TECHNICAL FIELD
[0001] The present invention relates to a method for applying a coating material onto a
fiber material, a method for manufacturing a fiber material, and an apparatus for
processing a fiber material, and more particularly to a method for applying a coating
material and an apparatus for processing a fiber material that can be used for, for
example, dyeing and antibacterial/deodorizing treatment of a fiber material.
BACKGROUND ART
[0002] Production industries such as textile and paper manufacturing are key industries
in Japan which contribute greatly, in particular, to local economy, but in recent
years, in the face of fierce international competition which is due to the development
of emerging economies, a demand has been created for further reduction in manufacturing
cost and improvement of performance and quality of products. For example, in the textile
industry, the treatment of the so-called dyeing wastewater which is generated in the
dyeing process has become an important problem. For example, when cellulose fibers
such as cotton or rayon are dyed, the fibers are typically charged into a dyeing bath
including a reactive dye, and the fibers are then taken out and the excess dye is
washed away. As a result, the dyeing bath and washing water are discharged as wastewater
including a large amount of dye. To resolve this problem, it has been suggested to
use, for example, a component derived from the Abelmoschus of Malvaceae genus as flocculant
for purifying dyeing wastewater (see PTL1). Another problem associated with the conventional
dyeing methods is that significant drying treatment is required and the methods are
not suitable for small-lot production of a large number of product types. In particular,
fuel consumption required for the drying treatment has been reduced by, for example,
the transition to fuels other than heavy oil and introduction of energy-saving equipment,
but the fuel consumption still reaches 606,000 kL (2011; in crude oil equivalent)
in the entire dyeing industry, and further reduction in the amount of fuel used is
needed.
[0003] Meanwhile, a phenomenon called "electrospray" in which a liquid is sprayed toward
a counter electrode as a result of applying a high voltage between a nozzle filled
with the liquid and the counter electrode has been used for mass analysis (see PTL2)
and deposition of polymer compounds, etc. (see PTL3). Since the electrospray phenomenon
enables ionization without requiring such conditions as high temperature, it is advantageous
for mass analysis of easily destructible compounds such as biopolymers. It is also
well known that because very small droplets of easily vaporizable solvents can be
sprayed, the electrospray phenomenon is advantageous for forming nanoparticles or
carbon nanofibers, etc.
CITATION LIST
PATENT LITERATURE
SUMMARY OF INVENTION
TECHNICAL PROBLEM
[0005] As indicated in PTL 1, adequately purifying the dyeing wastewater generated in the
fiber material dyeing process is a very important issue, but it is also important
to minimize the amount of the dyeing wastewater itself. For example, where utilization
efficiency of dye, etc. is increased by improving the dyeing method, etc., or the
method is made suitable for small-lot production of a large number of various products,
the production cost and environmental load can be reduced.
[0006] Further, in recent years a demand has been created for fibers having various functions
such as antibacterial/deodorizing activity and fire resistance, and the treatment
performed to impart those functions has also become a factor causing the generation
of a large amount of wastewater.
[0007] It is an objective of the present invention to provide novel processing method and
processing apparatus for a fiber material which are capable of resolving the above-described
problems associated with the dyeing and antibacterial/deodorizing treatment, etc.
SOLUTION TO PROBLEM
[0008] The inventors have conducted a comprehensive study aimed at the resolution of the
above-described problems. The results obtained have demonstrated that by comprising
an electrolyte solution in a fiber material, it is possible to apply efficiently a
coating material comprising a dye, an antibacterial agent, and a deodorant to the
fiber material by using the electrospray phenomenon. This finding led to the creation
of the present invention.
[0009] Thus, the present invention relates to:
- <1> A method for applying a coating material to a fiber material, the method comprising:
a preparation step of preparing a fiber material comprising an electrolyte solution;
and a spraying step of spraying the coating material onto the fiber material by electrospray.
- <2> The method for applying according to <1>, wherein the electrolyte solution comprises
at least one selected from a group consisting of alkali metal salts, alkaline earth
metal salts, aluminum salts, ammonium salts, and transition metal salts.
- <3> The method for applying according to <1> or <2>, wherein the preparation step
comprises at least one selected from a group consisting of: immersing the fiber material
into the electrolyte solution; spraying the electrolyte solution onto the fiber material;
and dropping the electrolyte solution onto the fiber material.
- <4> The method for applying according to any one of <1> to <3>, wherein the coating
material comprises at least one selected from a group consisting of a dye, an antibacterial
agent, a deodorant, a water and oil repellent, a flame retardant, a bleaching agent,
a softener, a sizing agent, and an anti-fouling agent.
- <5> The method for applying according to any one of <1> to <4>, wherein with the fiber
material comprising a reducing agent and with the coating material being a solution
that comprises a metal ion, when the coating material comprising the metal ion is
sprayed onto the fiber material in the spraying step, the metal ion reacts with the
reducing agent, and as a result a metal particle is generated in the fiber material.
- <6> The method for applying according to any one of <1> to <5>, wherein the spraying
step comprises spraying one or two or more types of coating materials by using two
or more electrospray sprayers.
- <7> The method for applying according to <6>, wherein the spraying step comprises
spraying one or two or more types of coating materials continuously by moving the
fiber material and/or the electrospray sprayers.
- <8> The method for applying according to any one of <1> to <7>, wherein the preparation
step and the spraying step are performed continuously by moving the fiber material
comprising the electrolyte solution.
- <9> The method for applying according to any one of <1> to <8>, wherein the fiber
material is a yarn, woven fabric, nonwoven fabric, knitted fabric, paper, or a film.
- <10> A method for manufacturing a fiber material, comprising at least one step selected
from a group consisting of (1) to (8) below:
- (1) a dye treatment step comprising dyeing a fiber material by applying a coating
material comprising a dye by the method for applying according to any one of <1> to
<9>;
- (2) an antibacterial/deodorizing treatment step comprising imparting an antibacterial
activity and/or a deodorizing activity to a fiber material by applying a coating material
comprising an antibacterial agent and/or a deodorant by the method for applying according
to any one of <1> to <9>;
- (3) a water and oil repelling treatment step comprising imparting a water and oil
repelling activity to a fiber material by applying a coating material comprising a
water and oil repellent by the method for applying according to any one of <1> to
<9>;
- (4) a flame retardant treatment step of making a fiber material less flammable by
applying a coating material comprising a flame retardant by the method for applying
according to any one of <1> to <9>;
- (5) a bleaching treatment step comprising bleaching a fiber material by applying a
coating material comprising a bleaching agent by the method for applying according
to any one of <1> to <9>;
- (6) a softening treatment step comprising softening a fiber material by applying a
coating material comprising a softener by the method for applying according to any
one of <1> to <9>;
- (7) a sizing treatment step comprising sizing a fiber material by applying a coating
material comprising a sizing agent by the method for applying according to any one
of <1> to <9>; and
- (8) an anti-fouling treatment step comprising imparting an anti-fouling activity to
a fiber material by applying a coating material comprising an anti-fouling agent by
the method for applying according to any one of <1> to <9>.
- <11> The method for manufacturing a fiber material according to <10>, further comprising
at least one step selected from a group consisting of a fiber forming step, a stretching
step, a spinning step, a knitting and weaving step, and a scouring step.
- <12> An apparatus for processing a fiber material, comprising: an electrolyte solution
contact mechanism performing at least one selected from a group consisting of immersing
the fiber material into an electrolyte solution, spraying the electrolyte solution
onto the fiber material, and dropping the electrolyte solution onto the fiber material;
an electrospray sprayer that sprays a coating material toward the fiber material comprising
the electrolyte solution; and a fiber material feed mechanism for moving the fiber
material comprising the electrolyte solution to a spray target for the electrospray
sprayer.
- <13> The apparatus for processing a fiber material according to <12>, comprising two
or more electrospray sprayers.
- <14> The apparatus for processing a fiber material according to <12> or <13>, comprising
an electrospray sprayer that sprays at least one coating material selected from a
group consisting of (1) to (8) below as the electrospray sprayer:
- (1) a coating material comprising a dye;
- (2) a coating material comprising an antibacterial agent and/or a deodorant;
- (3) a coating material comprising a water and oil repellent;
- (4) a coating material comprising a flame retardant;
- (5) a coating material comprising a bleaching agent;
- (6) a coating material comprising a softener;
- (7) a coating material comprising a sizing agent; and
- (8) a coating material comprising an anti-fouling agent.
ADVANTAGEOUS EFFECTS OF INVENTION
[0010] According to the present invention, the coating material can be efficiently applied
to the fiber material. Therefore, by using such technique for dyeing and antibacterial/deodorizing
treatment, it is possible to decrease the amount of wastewater generated in such treatment
and reduce the drying treatment. At the same time, the technique can be used for small-lot
production and production of products of a large number of types, and the production
cost of the fiber products and the environmental load can be reduced.
BRIEF DESCRIPTION OF DRAWIONGS
[0011]
[Fig. 1]
Fig. 1 is a conceptual diagram representing the state in which a coating material
is sprayed toward a fiber material by electrospray.
[Fig. 2]
Fig. 2(A) is a conceptual diagram showing how one or two or more coating materials
are continuously sprayed by moving the fiber material. Fig. 2(B) is a conceptual diagram
showing how one or two or more coating materials are sprayed at the same position
of the fiber material. Fig. 2(C) is a conceptual diagram illustrating how the spraying
is performed while moving an electrospray sprayer.
[Fig. 3]
Fig. 3(A) is a conceptual diagram illustrating how the spraying step is continuously
performed after the fiber material has been immersed into an electrolyte solution
in the preparation step. Fig. 3(B) is a conceptual diagram illustrating how the spraying
step is continuously performed after the electrolyte solution has been sprayed onto
the fiber material in the preparation step. Fig. 3(C) is a conceptual diagram illustrating
how the spraying step is continuously performed after the electrolyte solution has
been dropped onto the fiber material in the preparation step.
[Fig. 4]
Fig. 4(A) is a photograph (photograph replacing the drawing) illustrating the state
in which ethanol of Example 1 is sprayed. Fig. 4(B) is a photograph (photograph replacing
the drawing) illustrating the state in which ethanol of Comparative Example 1 is sprayed.
Fig. 4(C) is a conceptual diagram showing how droplets sprayed from the nozzle are
focused toward a cotton yarn.
[Fig. 5]
Fig. 5(A) is a conceptual diagram of the device used in Example 2. Fig. 5(B) is a
top view of an electrospray sprayer portion of the device used in Example 2.
[Fig. 6]
Fig. 6 is a photograph (photograph replacing the drawing) illustrating the state in
which the dye solution of Example 2 is sprayed.
[Fig. 7]
Fig. 7(A) is a conceptual diagram of the device used in Example 3. Fig. 7(B) is a
top view of an electrospray sprayer portion of the device used in Example 3. Fig.
7(C) is a photograph (photograph replacing the drawing) illustrating the state in
which the dye solution of Example 3 is sprayed.
[Fig. 8]
Fig. 8 is a photograph (photograph replacing the drawing) of a cotton yarn which has
been multicolor dyed in Example 3.
[Fig. 9]
Fig. 9 is a photograph (photograph replacing the drawing) illustrating the state in
which the dye solution of Comparative Example 2 is sprayed.
[Fig. 10]
Fig. 10(A) is a conceptual diagram of the device used in Example 4. Fig. 10(B) is
a top view of an electrospray sprayer portion of the device used in Example 4.
[Fig. 11]
Fig. 11 is a conceptual diagram of the device for washing the cotton yarn with water.
[Fig. 12]
Fig. 12(A) shows a photograph (photograph replacing the drawing) of a cotton yarn
before impregnation with metallic silver particles (left side) and a photograph of
the cotton yarn impregnated with metallic silver particles in Example 4 (right side),
and Fig. 12(B) is a scanning electron microphotograph (photograph replacing the drawing)
of the cotton yarn impregnated with metallic silver particles in Example 4.
[Fig. 13]
Fig. 13 is a conceptual diagram illustrating how a cotton yarn successively passes
through a tank filled with an electrolyte solution, a dyeing treatment step, a functional
material addition (antibacterial/deodorizing treatment) step, a sizing treatment step
and a heating and drying device.
[Fig. 14]
Fig. 14 is a graph representing the relationship between the feed rate of a cotton
yarn and the impregnated amount of metallic silver particles.
[Fig. 15]
Fig. 15(A) is a conceptual diagram of the device used in Example 6, and Fig. 15(B)
is a photograph (photograph replacing the drawing) of a silk yarn subjected to plant
dyeing in Example 6.
[Fig. 16]
Fig. 16(A) is a conceptual diagram of the device used in Example 7, and Fig. 16(B)
is a photograph (photograph replacing the drawing) of a cotton yarn subjected to gradation
dyeing in Example 7.
[Fig. 17]
Fig. 17(A) is a conceptual diagram of the device used in Example 8, and Fig. 17(B)
is a photograph (photograph replacing the drawing) of a silk yarn subjected to gradation
dyeing in Example 8.
[Fig. 18]
Fig. 18(A) is a conceptual diagram of the device used in Example 9, and Fig. 18(B)
is a photograph (photograph replacing the drawing) of a cotton yarn subjected to deep-color
dyeing in Example 9.
[Fig. 19]
Fig. 19 is a photograph (photograph replacing the drawing) of a paper yarn dyed in
Example 10.
[Fig. 20]
Fig. 20 is a photograph (photograph replacing the drawing) of a cotton yarn dyed by
using various reactive dyes.
DESCRIPTION OF EMBODIMENTS
[0012] The method for applying a coating material to a fiber material, the method for manufacturing
a fiber material, and the apparatus for processing a fiber material, which are the
embodiments of the present invention, are explained hereinbelow in detail by referring
to specific examples, but they are not limited to the contents described hereinbelow
and can be changed, as appropriate, provided that they do not depart from the essence
of the present invention.
<Method for applying a coating material to a fiber material>
[0013] A method for applying a coating material to a fiber material which is an aspect of
the present invention (can be referred to hereinbelow as "application method according
to the present invention") is characterized in comprising a preparation step of preparing
a fiber material comprising an electrolyte solution (can be referred to hereinbelow
in abbreviated form as "preparation step"), and a spraying step of spraying the coating
material onto the fiber material by electrospray (can be referred to hereinbelow in
abbreviated form as "spraying step").
[0014] The inventors have conducted a comprehensive research of novel methods for processing
fiber materials that can be used for dyeing and antibacterial/deodorizing treatment,
etc. The results obtained have demonstrated that a coating material comprising a dye,
an antibacterial agent, a deodorant, etc., can be efficiently applied to a fiber material
by comprising an electrolyte solution in the fiber material and using an electrospray
phenomenon. With the electrospray phenomenon, a high voltage is applied between a
nozzle filled with a liquid and a counter electrode to generate an electric field
between the nozzle and the counter electrode, whereby the liquid is sprayed toward
the counter electrode in the form of charged droplets. The problem associated with
this method is that when the spraying object is an insulator such as a fiber material,
the electric field is difficult to generate between the insulator and the nozzle,
and the coating material cannot be applied with good efficiency. The inventors have
discovered that by imparting electric conductivity to the fiber material by comprising
an electrolyte solution therein, it is possible to generate an electric field between
the fiber material and the nozzle and enable the application using the electrospray
phenomenon. The electric field between the nozzle and fiber material can be generated
by using, for example, an electric power source and setting the nozzle side to a positive
potential and setting the fiber material side to 0 kV or a negative potential, or
by setting the nozzle side to a negative potential and setting the fiber material
side to 0 kV or a positive potential. Further, since a potential gradient may be created
between the nozzle and the fiber material, the electrospray phenomenon can be generated,
for example, also when (potential of nozzle) > (potential of fiber material) > 0,
or when 0 V > (potential of fiber material) > (potential of nozzle). With such an
electrospray method, since the generated charged droplets are drawn by the electric
field to the spraying object, the coating material can be applied with good efficiency.
Therefore, by using such a method for dyeing and antibacterial/deodorizing treatment,
it is possible, for example, to decrease the amount of wastewater generated in such
treatment and reduce the drying treatment. Furthermore the method is suitable for
small-lot production and production of a large number of various products and can
reduce the production cost and environmental load. When the application method according
to the present invention is used for dyeing a fiber material, the electrolyte solution
also plays the role of a fixing agent ("dyeing enhancer") for fixing the dye to the
fiber material. As a result, the dyeing is performed with a very high efficiency.
[0015] The "fiber material", as referred to in the present invention, means a fibrous material
comprising a polymer compound as a constituent component, or a material obtained by
bundling such fibrous material (cotton, woven fabric, nonwoven fabric, paper, etc.),
and the specific material, whether natural fibers or synthetic fibers, and form of
the material, etc. are not particularly limited. Further, the present invention is
not intended to exclude the use of the application method when processing into garments
and paper products, and the application method according to the present invention
is also inclusive of the use of the application method with products in which the
shape of a fiber material is retained.
[0016] The expression "spraying the coating material onto the fiber material by electrospray"
is assumed to mean that the coating material is sprayed onto the fiber material by
using the electrospray phenomenon, that is, the coating material is loaded into the
nozzle of a sprayer, an electric field is generated between the nozzle and the fiber
material which is the spraying object, and the coating material is sprayed toward
the fiber material (a device for spraying the coating material by using the electrospray
phenomenon can be referred to hereinbelow in abbreviated form as "electrospray sprayer").
A conceptual diagram illustrating the state in which the coating material is sprayed
onto the fiber material by electrospray is shown in Fig. 1 (the reference numeral
101 stands for a fiber material comprising an electrolyte solution; 102 - a nozzle
of an electrospray sprayer; 103 - a sprayed coating material; and 104 - a distance
between the nozzle of the electrospray sprayer and the fiber material; the fiber material
101 and the nozzle of the electrospray sprayer are connected through an electrode,
conductive, a power source, and the like). The electrospray sprayer is usually equipped
with at least a nozzle for defining the spraying direction, and a power source (voltage-controlled
device; includes an electrode, a conductive wire, etc., connecting the nozzle and
fiber material) for generating an electric field between the nozzle and the fiber
material which is the spraying object (when two or more electrospray sprayers are
used, the electrospray sprayers may share a power source, or each of the electrospray
sprayers may not be equipped with a power source). The nozzle itself is fabricated
from an electrically conductive material, or an electrode (for example, a platinum
wire) is disposed in the nozzle. The arrangement is such that the nozzle and the fiber
material which is the spraying object are each connected to the power source (voltage-controlled
device, etc.) and an electric field is generated between the nozzle and fiber material
by applying a voltage thereto.
(Preparation step)
[0017] In the preparation step according to the present invention, a fiber material is prepared
which is to be used in the below-describes spraying step. A specific preparation method
is not particularly limited, and the fiber material comprising an electrolyte solution
may be purchased or may be produced. When the fiber material comprising the electrolyte
solution is produced, the production method is not particularly limited, and the examples
of suitable methods comprise a method for immersing the fiber material into the electrolyte
solution, a method for spraying the electrolyte solution onto the fiber material,
and a method for dropping the electrolyte solution onto the fiber material. The preparation
step according to the present invention is preferably a step comprising at least one
selected from a group consisting of: immersing the fiber material into the electrolyte
solution; spraying the electrolyte solution onto the fiber material; and dropping
the electrolyte solution onto the fiber material.
[0018] The type, concentration, content, etc. of the electrolyte in the electrolyte solution
comprised in the fiber material are not particularly limited and they can be selected,
as appropriate, according to, for example, the type of the coating material which
is to be applied and the type of the fiber material (for example, a neutral electrolyte
or an alkaline electrolyte can be selected according to the type of the fiber material).
[0019] Examples of suitable electrolytes include alkali metal salts, alkaline earth metal
salts, and aluminum salts such as sodium carbonate, sodium acetate, sodium sulfate,
sodium hydroxide, sodium chloride, magnesium chloride, aluminum sulfate, aluminum
carbonate, potassium carbonate, potassium acetate, potassium sulfate, potassium chloride,
calcium chloride, and potassium alum, and also ammonium salts such as ammonium carbonate,
ammonium acetate, ammonium sulfate, ammonium hydroxide, and ammonium chloride, and
transition metal salt such as iron chloride and iron sulfate. Among them, it is preferred
that at least one be selected from a group consisting of sodium carbonate, sodium
acetate, sodium sulfate, sodium hydroxide, aluminum sulfate, aluminum carbonate, ammonium
acetate, potassium alum, and iron sulfate.
[0020] The concentration of the electrolyte solution is generally 0.001% by mass or more,
preferably 0.1% by mass or more, more preferably 2.5% by mass or more, and usually
20.0% by mass or less, preferably 15.0% by mass or less, more preferably 10.0% by
mass or less. When the concentration is within such ranges, the coating material can
be applied with good efficiency.
[0021] The content of the electrolyte solution comprised in the fiber material (mass of
the electrolyte solution in 100% by mass the fiber material) is usually 300% by mass
or more, preferably 400% by mass or more, more preferably 500% by mass or more, and
usually 1000% by mass or less, preferably 850% by mass or less, more preferably 700%
by mass or less. Within those ranges, the coating material can be applied with good
efficiency.
[0022] The fiber material prepared in the preparation step according to the present invention
may comprise a reducing agent. For example, the fiber material comprises a reducing
agent, and where a coating material comprising metal ions is sprayed in the spraying
step according to the present invention, the metal ions react with the reducing agent,
thereby generating metal particles in the fiber material (this procedure will be described
hereinbelow in greater detail).
[0023] Examples of the reducing agent include sodium borohydride, lithium aluminum hydride,
sulfites, nitrites, hydrazine, ascorbic acid and salts thereof, and oxalic acid and
salts thereof. Since these reducing agents also act as an electrolyte, solutions comprising
these reducing agents may be used as the electrolyte solution instead of the electrolyte
described hereinabove.
[0024] The fiber material prepared in the preparation step according to the present invention
is not necessarily required to comprise the electrolyte solution over the entire surface,
and the electrolyte solution may be comprised locally. In the electrospray method,
the sprayed droplets are drawn to the charged portions. Therefore, the electrospray
method can be also used for applying a coating material locally to the fiber material.
[0025] An immersion method which is used when the preparation method of the present invention
involves immersing the fiber material into the electrolyte solution is not particularly
limited. For example, a method can be used by which the fiber material is immersed
in a liquid tank filled with the electrolyte solution. Further, a spraying method
which is used when the electrolyte solution is sprayed onto the fiber material is
not particularly limited, and a method can be used by which the electrolyte solution
is sprayed onto the fiber material by using a well-known sprayer such as a spray gun.
A dropping method which is used when the electrolyte solution is dropped on the fiber
material is not particularly limited, and a method can be used by which the electrolyte
solution is dropped onto the fiber material by using a well-known dropping device.
(Spraying step)
[0026] In the spraying step according to the present invention, the coating material is
sprayed by electrospray toward the fiber material prepared in the above-described
preparation step. The structure, etc. of the electrospray sprayer to be used is not
particularly limited and a well-known structure can be selected as appropriate. The
nozzle itself is usually fabricated from an electrically conductive material, or an
electrode (for example, a platinum wire) is disposed inside the nozzle, so that the
loaded coating material be in contact with the electric field generated by voltage
application.
[0027] The diameter of the spraying port of the nozzle of the electrospray sprayer is usually,
0.03 mm or more, preferably 0.05 mm or more, more preferably 0.1 mm or more, and usually
1.0 mm or less, preferably 0.5 mm or less, more preferably 0.3 mm or less. Where the
diameter is within those ranges, the coating material can be applied with good efficiency.
[0028] In the spraying step according to the present invention, the coating material is
sprayed toward the fiber material by electrospray, but since the sprayed coating material
is drawn by the generated electric field to the fiber material, it is not always necessary
that the fiber material be present on the spraying direction of the nozzle of the
electrospray sprayer. Thus, the fiber material is preferably present in a range within
45°, more preferably in a range within 30° from the spraying direction of the nozzle
of the electrospray sprayer. Within those ranges, the coating material can be applied
with good efficiency.
[0029] The distance between the nozzle of the electrospray sprayer and the fiber material
in the spraying step according to the present invention (the shortest distance between
the nozzle tip of the electrospray sprayer and the fiber material) is usually 5 mm
or more, preferably 7 mm or more, more preferably 10 mm or more, and usually 40 mm
or less, preferably 30 mm or less, and more preferably 20 mm or less. Within those
ranges, the coating material can be applied with good efficiency.
[0030] The applied voltage in the spraying step according to the present invention (the
difference in potential generated between the nozzle and fiber material) is usually
5.5 kV or more, preferably 6 kV or more, more preferably 7 kV or more, and usually
16 kV or less, preferably 15 kV or less, and more preferably 12 kV or less.
[0031] Further, the electric potential applied to the nozzle is usually a positive potential,
and this potential, in the case of ground taken as a reference potential, is usually
+2.0 kV or more, preferably +3.0 kV or more, more preferably +4.5 kV or more, and
usually +10.0 kV or less, preferably +8 kV or less, even more preferably +7 kV or
less.
[0032] Meanwhile, the electric potential applied to the fiber material is usually a negative
potential, and this potential, in the case of ground taken as a reference potential,
is usually -5 kV or more, preferably -4 kV or more, more preferably - 3.5 kV or more,
and usually -0.5 kV or less, preferably -1 kV or less, even more preferably -2 kV
or less.
[0033] Within those ranges, the coating material can be applied with good efficiency.
[0034] The sprayed amount of the coating material in the spraying step according to the
present invention is usually 3 µL/min or more, preferably 5 µL/min or more, more preferably
7 µL/min or more, and usually 50 µL/min or less, preferably 30 µL/min or less, more
preferably 20 µL/min or less. Within those ranges, the coating material can be applied
with good efficiency.
[0035] Components to be comprised in the coating material which is to be sprayed in the
spraying step according to the present invention can be selected, as appropriate,
according to the application target (usage of the application method). The components
to be comprised in the coating material can be classified, for example, into (a) modifying
and functionalizing components and auxiliary components that are used for modifying
the fiber material or for imparting functions to the fiber material; (b) starting
material compounds of the substances to be formed in the fiber material; and (c) solvents.
Those groups (a) to (c) of components will be explained hereinbelow in greater detail.
(a) Modifying or functionalizing components and auxiliary components
[0036] The "modifying and functionalizing components", as referred to herein, mean well-known
components that are used for modifying fiber materials or for imparting functions
to fiber materials, examples thereof comprising dyes (pigments) for dying fiber materials
and also antibacterial agents, deodorants, water and oil repellents, flame retardants,
bleaching agents, softeners, sizing agents, and anti-fouling agents. The "auxiliary
components" means auxiliary components that are used for processing fiber materials,
examples thereof comprising surfactants which are used for increasing dispersivity
and fixability of the dye and also acids and bases which are used in the dye. Specific
types of dyes, etc., are listed below, but the modifying and functionalizing components
that can be used for fiber materials are widely commercially available, and the application
method according to the present invention is not limited to the components listed
below. The "dye", as referred to in the present invention, is assumed to be also inclusive
of "pigments" which are not soluble in solvents.
- Dyes (pigments)
[0037] Direct dyes, acidic dyes (leveling dyes, half-milling dyes, milling dyes), disperse
dyes (azo, quinone), reactive dyes, cationic dyes, vat dyes, sulfur dyes, and naphthol
dyes.
- Antibacterial agents, deodorants
[0038] Silver, titanium oxide, zinc oxide, gold, platinum, copper, zeolites, charcoal, triazine
compounds, phenol compounds, chitin, and chitosan.
- Water and oil repellents
[0039] Fluorine-based polymer compounds, silicon-based polymer compounds, and polyolefin-based
polymer organic compounds.
- Flame retardants
[0040] Phosphorus-based organic compounds, halogen compounds, ammonium sulfate, antimony
oxide, aluminum hydroxide, and sodium silicate.
(b) Starting material compounds
[0041] The "starting material compounds", as referred to herein, specifically means starting
material compounds of the substances that are to be formed in the fiber material,
for example, a component effective in applying inorganic solid compounds such as silver
and titanium oxide which are used as antibacterial agent and deodorant to the fiber
material. Specific examples of the starting material compounds comprise metal ions
(metal salts) serving as starting materials for inorganic solid compounds, organometallic
compounds, oxidizing agents that oxidize metal ions or organometallic compounds, and
reducing agents therefor.
- Metal ions (metal salts)
[0042] Silver nitrate (AgNO
3), tetrachloroauric (III) acid (HAuCl
4), hexachloroplatinic acid (H
2PtCl
6), and copper (II) chloride (CuCl
2).
- Organometallic compounds
- Oxidizing agents
[0044] Hydrogen peroxide, ozone, hydrochloric acid, and sulfuric acid.
- Reducing agents
[0045] Sodium borohydride, lithium aluminum hydride, sulfites, nitrites, hydrazine, ascorbic
acid and salts thereof, oxalic acid and salts thereof.
(c) Solvents
[0046] The solvent to be used in the coating material needs to be selected, as appropriate,
according to the components etc. to be comprised in the coating material. From the
standpoint of cost, water is usually used. Examples of solvents that can be used in
addition to water comprise protic polar solvents such as methanol, ethanol, 1-propyl
alcohol, 2-propyl alcohol, butanol, acetic acid, and formic acid; aprotic polar solvents
such as acetone, methyl ethyl ketone, acetonitrile, N,N-dimethylformamide, N,N-dimethylacetamide,
N-methyl-2-pyrrolidone, and dimethyl sulfoxide; and nonpolar solvents such as hexane,
cyclohexane, cyclohexanone, dichloromethane, dichloroethane, trichloroethane, chloroform,
trichloroethylene, benzene, ethylbenzene, xylene, toluene, diethyl ether, 1,4-dioxane,
methyl acetate, ethyl acetate, tetrahydrofuran, and methylene chloride. Those solvents
may be used not only individually, but also in combinations of two or more thereof.
[0047] The concentration of the components comprised in the coating material which is to
be sprayed in the spraying step according to the present invention is selected, as
appropriate, according to the type of the components and the like, but is usually
0.05% by mass or more, preferably 0.1% by mass or more, more preferably 0.25% by mass
or more, and usually 2.0% by mass or less, preferably 1.5% by mass or less, more preferably
1.0 mass% or less. Within those ranges, the coating material can be applied with good
efficiency.
[0048] In a preferred embodiment of the spraying step according to the present invention,
a coating material comprising metal ions is sprayed onto the fiber material. For example,
where the fiber material comprises a reducing agent, by spraying the coating material
comprising metal ions in the spraying process according to the present invention,
it is possible to generate metal particles in the fiber material by a reaction of
the metal ions with the reducing agent.
[0049] The type (element) of the metal particles to be produced in such a manner and the
form of the particles, etc. are not particularly limited, but noble metals with an
ionization tendency less than that of hydrogen are preferred. The preferred specific
examples include copper, silver, palladium, platinum, and gold. With such metals,
the generation of particles in the fiber material is facilitated, and the antibacterial
activity and deodorizing activity based on bacteria growth inhibition are demonstrated.
Therefore, the method can be used as an antibacterial and deodorizing method that
imparts the antibacterial activity and/or deodorizing activity to the fiber material.
Further, the average particle diameter of the generated metal particles is usually
100 nm or less, preferably 70 nm or less, more preferably 50 nm or less, and usually
1 nm or more, preferably 2 nm or more, more preferably 3 nm or more. The average particle
size of the metal particles specifically means a volume average particle diameter.
It can be measured, for example, by electron microscopy or dynamic light scattering
method.
[0050] The spraying step according to the present invention may be a step in which one or
two or more coating materials are sprayed using two or more electrospray sprayers.
One or two or more coating materials can be sprayed using two or more electrospray
sprayers, for example, in a mode illustrated by Fig. 2(A) in which the fiber material
is moved and one or two or more coating materials are sprayed continuously (can be
referred to hereinbelow in abbreviated form as "the mode illustrated by Fig. 2(A)"),
or a mode illustrated by Fig. 2(B) in which one or two or more coating materials are
sprayed on the same position of the fiber material (can be referred to hereinbelow
in abbreviated form as "the mode illustrated by Fig. 2(B)") (in Fig. 2, the reference
numeral 201 stands for a fiber material comprising an electrolyte solution, 202 -
an electrospray sprayer, 203 - a sprayed coating material, and 204 - a sprayed coating
material of a type different from that of 203).
[0051] The mode illustrated by Fig. 2(A) can be used, for example, when dyes of the same
or different colors are continuously applied and also when an antibacterial agent
and/or a deodorant is applied after a dye has been applied. In the mode illustrated
by Fig. 2(A), a conductive wire or an electrode for applying an electric potential
to the fiber material are not fixed to the fiber material (for example, a voltage
applying electrode denoted by the reference numeral 507 in Fig. 5), as an overhead
wire and a pantograph in railroad trains, in order to move the fiber material.
[0052] Examples of more specific modes include a dyeing method in which color and shade
are continuously changed by applying dyes of different colors (gradation dyeing, see
Examples 7 and 8); a dyeing method in which the color tone is adjusted by applying
three primary colors, black color, and white color, etc.; and a dyeing method in which
a color is darkened by applying the same color (dark dyeing, see Example 9). Further,
in those dyeing methods, more sophisticated dyeing, etc. can be performed by adjusting
precisely the amount of the fiber material by using a shutter (for example, filter
paper shutters 1609, 1709 in Examples 7 and 8) that temporarily blocks the application
of the sprayed coating material to the fiber material, or by ON/OFF switching the
power supply relay.
[0053] The mode illustrated by Fig. 2(B) can be used, for example, when the same or different
coating materials are simultaneously applied to the same position of the fiber material.
[0054] The spraying step according to the present invention may be a step involving spraying
while moving the electrospray sprayer. An example of a mode of spraying while moving
the electrospray sprayer is presented in Fig. 2(C) (can be referred to hereinbelow
in abbreviated form as "the mode illustrated by Fig. 2(C)").
[0055] The mode illustrated by Fig. 2(C) can be used, for example, when a dye is wished
to be applied selectively or when a dye is wished to be applied in a focused manner.
[0056] The application method of the present invention is not otherwise particularly limited,
provided that it comprises the above-described preparation step and spraying step.
Thus the application method may comprise, in addition to the preparation step and
spraying step, a washing step of washing away the electrolyte solution and/or coating
material from the fiber material, a drying step of drying the fiber material, and
a blending step of comprising a reducing agent in addition to the electrolyte solution
in the fiber material. Further, the application method of the present invention is
not limited to the embodiments in which the preparation step and spraying step are
performed once each, and the preparation step and spraying step may be each performed
a plurality of times, with the other step being interposed therebetween. Furthermore,
in the application method according to the present invention, instead of implementing
the preparation step and spraying step individually, the so-called line production
method may be used in which the preparation step and spraying step are performed continuously,
for example, by moving the fiber material comprising the electrolyte solution. By
performing the preparation step and spraying step continuously, it is possible to
apply the coating material more efficiently. Examples of modes for "performing the
preparation step and spraying step continuously by moving the fiber material" are
illustrated by Fig. 3. Thus, Fig. 3(A) illustrates a mode in which the fiber material
is immersed in the electrolyte solution as a preparation step, and the spraying step
is performed continuously thereafter. Fig. 3(B) illustrates a step in which the electrolyte
solution is sprayed onto the fiber material as the preparation step, and the spraying
step is performed continuously thereafter. Fig. 3(C) illustrates a step in which the
electrolyte solution is dropped onto the fiber material as the preparation step, and
the spraying step is performed continuously thereafter (in Fig. 3, the reference numeral
301 stands for a fiber material, 302 - a roller, 303 - an electrospray sprayer, 304
- a sprayed coating material, 305 - a water tank, 306 - an electrolyte solution, 307
- a spray device for spraying the electrolyte solution, 308 - the sprayed electrolyte
solution, 309 - a dropping device, and 310 - a dropped electrolyte solution).
(Fiber material)
[0057] The specific material, whether natural fibers or synthetic fibers, and form of the
"fiber material", which is the object of the application method of the present invention,
are not particularly limited, provided that it is a fibrous material comprising a
polymer compound as a constituent component, or a material obtained by bundling such
fibrous material (cotton, woven fabric, nonwoven fabric, paper, etc.).
[0058] Examples of the types of the fiber material comprise plant fibers such as hemp and
cotton, animal fibers such as wool and silk, regenerated fibers such as rayon, polyamide
synthetic fibers, polyester synthetic fiber, acrylic synthetic fibers, polyvinyl alcohol
synthetic fibers, polyolefin synthetic fiber, polyurethane synthetic fibers, cellulose-based
semisynthetic fibers, and protein-based semisynthetic fibers.
[0059] The fiber material is preferably a yarn, woven fabric, nonwoven fabric, knitted fabric,
paper, or a film.
[0060] The application method of the present invention can be used for a variety of treatments
performed in the process of manufacturing or processing the fiber material, and the
use thereof is not particularly limited. For example, it can be used in the below-described
methods (1) to (8).
- (1) a dyeing method for a fiber material in which the fiber material is dyed by applying
a coating material comprising a dye;
- (2) an antibacterial/deodorizing method for a fiber material comprising imparting
an antibacterial activity and/or a deodorizing activity to the fiber material by applying
a coating material comprising an antibacterial agent and/or a deodorant;
- (3) a water and oil repelling method for a fiber material comprising imparting a water
and oil repelling activity to the fiber material by applying a coating material comprising
a water and oil repellent;
- (4) a flame retardant method for a fiber material by which the fiber material is made
less flammable by applying a coating material comprising a flame retardant;
- (5) a bleaching method for a fiber material comprising bleaching the fiber material
by applying a coating material comprising a bleaching agent;
- (6) a softening method for a fiber material comprising softening the fiber material
by applying a coating material comprising a softener;
- (7) a sizing method for a fiber material comprising sizing the fiber material by applying
a coating material comprising a sizing agent; and
- (8) an anti-fouling method for a fiber material comprising imparting an anti-fouling
activity to the fiber material by applying a coating material comprising an anti-fouling
agent.
[0061] The continuous treatment such as depicted in Fig. 13 is a specific mode of using
the application method of the present invention (can be referred to hereinbelow in
abbreviated form as "the mode illustrated by Fig. 13") (in Fig. 13, the reference
numeral 1301 stands for a fiber material before processing (for example, a cotton
yarn), 1302 - a water tank that contains the electrolyte solution, 1303 - a dyeing
treatment step, 1304 - a functional material addition (antibacterial/deodorizing treatment)
step, 1305 - a sizing treatment step, 1306 - an electrospray sprayer, and 1307 - a
heating and drying device).
[0062] The mode illustrated by Fig. 13 is a line production method in which a cotton yarn
(fiber material) is moved using a roller. The cotton yarn passes successively through
the water tank that contains the electrolyte solution, dyeing treatment step, functional
material addition (antibacterial/deodorizing treatment) step, sizing treatment step,
and heating and drying device.
<Method of manufacturing fiber material>
[0063] It has been mentioned hereinbefore that the application method of the present invention
can be used, for example, in the methods (1) to (8), but a method for manufacturing
a fiber material that comprises those methods as treatment steps is also an aspect
of the present invention (can be referred to hereinbelow in abbreviated form as "the
manufacturing method of the present invention").
[0064] Thus, the manufacturing method of the present invention is characterized by comprising
at least one step selected from a group consisting of steps (1) to (8) below:
- (1) a dye treatment step comprising dyeing a fiber material by applying a coating
material comprising a dye by the application method according to the present invention;
- (2) an antibacterial/deodorizing treatment step comprising imparting an antibacterial
activity and/or a deodorizing activity to a fiber material by applying a coating material
comprising an antibacterial agent and/or a deodorant by the application method according
to the present invention;
- (3) a water and oil repelling treatment step comprising imparting a water and oil
repelling activity to a fiber material by applying a coating material comprising a
water and oil repellent by the application method according to the present invention;
- (4) a flame retardant treatment step of making a fiber material less flammable by
applying a coating material comprising a flame retardant by the application method
according to the present invention;
- (5) a bleaching treatment step comprising bleaching a fiber material by applying a
coating material comprising a bleaching agent by the application method according
to the present invention;
- (6) a softening treatment step comprising softening a fiber material by applying a
coating material comprising a softener by the application method according to the
present invention;
- (7) a sizing treatment step comprising sizing a fiber material by applying a coating
material comprising a sizing agent by the application method according to the present
invention; and
- (8) an anti-fouling treatment step comprising imparting an anti-fouling activity to
a fiber material by applying a coating material comprising an anti-fouling agent by
the application method according to the present invention.
[0065] In addition to the above-described steps (1) to (8), the manufacturing method of
the present invention may comprise well-known steps that are performed in the processes
for manufacturing fiber materials, for example, a fiber forming step (melt fiber forming,
dry fiber forming, wet fiber forming), a stretching step, a spinning step, a knitting
and weaving step, and a scouring step. In particular, the manufacturing method of
the present invention is suitable for continuously implementing the steps of applying
a coating material to a fiber material, such as the above-described steps (1) to (8)
and makes it possible to increase greatly the productivity of fiber materials when
implemented continuously in combination with a fiber forming step or the like.
[0066] Thus, the manufacturing method of the present invention preferably further comprises
at least one step selected from a group consisting of a fiber forming step, a stretching
step, a spinning step, a knitting and weaving step, and a scouring step.
<Apparatus for processing fiber material>
[0067] The application method of the present invention, in particular the application method
in which the preparation step and spraying step are performed continuously by moving
the fiber material comprising the electrolyte solution, enables efficient processing
of the fiber material, and an apparatus for processing a fiber material that can be
used in such application method is also an aspect of the present invention (can be
referred to hereinbelow in abbreviated form as "apparatus for processing a fiber material
of the present invention").
[0068] Thus, the apparatus for processing a fiber material of the present invention comprises:
an electrolyte solution contact mechanism performing at least one selected from a
group consisting of immersing the fiber material into an electrolyte solution, spraying
the electrolyte solution onto the fiber material, and dropping the electrolyte solution
onto the fiber material; an electrospray sprayer that sprays a coating material toward
the fiber material comprising the electrolyte solution; and a fiber material feed
mechanism for moving the fiber material comprising the electrolyte solution to the
spray target for the electrospray sprayer.
[0069] For instance, a device to be used in the electrolyte solution contact mechanism in
the apparatus for processing a fiber material of the present invention is not particularly
limited, provided that an arrangement is obtained for performing at least one selected
from a group consisting of immersing the fiber material into an electrolyte solution,
spraying the electrolyte solution onto the fiber material, and dropping the electrolyte
solution onto the fiber material. For example, an arrangement in which the fiber material
301 is immersed in the immersion liquid tank 305 into which the electrolyte solution
306 has been loaded, as depicted in Fig. 3(A), an arrangement in which the electrolyte
solution 308 is sprayed onto the fiber material 301 by using the spraying device 307,
as depicted in Fig. 3(B), and an arrangement in which the electrolyte solution 310
is dropped onto the fiber material 301 by using the dropping device 309, as depicted
in Fig. 3(C), can be used.
[0070] The apparatus for processing a fiber material of the present invention is preferably
provided with two or more electrospray sprayers. Where two or more electrospray sprayers
are provided, coating materials of two or more types can be sprayed, and the above-described
modes illustrated by Fig. 2(A) and Fig. 2(B) can be implemented.
[0071] In the electrospray sprayer in the apparatus for processing a fiber material of the
present invention, the type of the coating material to be sprayed can be selected,
as appropriate, according to the processing object. For example, a coating material
of at least one type selected from a group consisting of (1) to (8) hereinbelow can
be used.
- (1) a coating material comprising a dye;
- (2) a coating material comprising an antibacterial agent and/or a deodorant;
- (3) a coating material comprising a water and oil repellent;
- (4) a coating material comprising a flame retardant;
- (5) a coating material comprising a bleaching agent;
- (6) a coating material comprising a softener;
- (7) a coating material comprising a sizing agent; and
- (8) a coating material comprising an anti-fouling agent.
[0072] A device to be used in the fiber material feed mechanism in the apparatus for processing
a fiber material of the present invention is not particularly limited, provided that
an arrangement is obtained such that the fiber material comprising the electrolyte
solution can be moved to the spray target for the electrospray sprayer. For example,
a roller conveyor or a belt conveyor can be used.
[0073] Other features of the apparatus for processing a fiber material of the present invention
are not particularly limited, but it is preferred that the apparatus be configured
such that the distance between the electrospray sprayer and the fiber material which
is the spraying object, or the spraying direction of the electrospray sprayer could
be changed. By enabling such changes, it is possible to adapt the apparatus to various
processing applications and processing conditions.
[0074] It is also preferred that a power source (voltage-controlled device) that generates
an electric field between the electrospray sprayer and the fiber material which is
the spraying object have a variable application voltage. Where the application voltage
can be changed, it is possible to adapt the apparatus to various processing applications
and processing conditions.
[0075] It is also preferred that a shutter be provided for blocking the application of the
sprayed coating material to the fiber material. By providing the shutter, it is possible
to adjust precisely the amount of the coating material to be applied and perform more
sophisticated dyeing, etc.
EXAMPLES
[0076] The present invention will be explained hereinbelow in greater detail on the basis
of examples and comparative examples, but the present invention can be changed, as
appropriate, without departing from the spirit thereof. Therefore, the scope of the
invention should not be interpreted as being limited to the below-described specific
examples.
<Example 1>
[0077] A cotton yarn (material: cotton, thickness: No. 4 single yarn) manufactured by ASAHIBO
CO., LTD. was immersed in an aqueous solution of sodium carbonate (concentration:
5% by mass) to prepare a cotton yarn comprising the aqueous solution of sodium carbonate.
[0078] An electrospray sprayer having a nozzle in the form of a glass capillary (opening
diameter 0.1 mm) with an electrode attached to the tip thereof and the cotton yarn
comprising the aqueous solution of sodium carbonate were each connected to a high-voltage
power source device (the nozzle electrode was connected to the positive electrode,
the cotton yarn was connected to the negative electrode, a reference electrode was
grounded). The cotton yarn was then positioned on the spraying direction of the nozzle,
and the nozzle tip and cotton yarn were fixed such that the shortest distance therebetween
was 30 mm. Spraying of ethanol toward the cotton yarn was started by applying an electric
potential of +3.0 kV to the nozzle electrode and -1.4 kV (reference potential: ground)
to the cotton yarn. A photograph illustrating the state of spraying is shown in Fig.
4(A).
<Comparative Example 1>
[0079] Ethanol was sprayed toward the cotton yarn in the same manner as in Example 1, except
that the cotton yarn was not immersed in the aqueous solution of sodium carbonate
(concentration: 5% by mass). A photograph illustrating the state of spraying is shown
in Fig. 4(B).
[0080] As clearly follows from Figs. 4(A) and 4(B), when the cotton yarn was immersed in
the electrolyte solution, the droplets focused to the cotton yarn, whereas when the
cotton yarn was not immersed in the electrolyte solution, the droplets diffused within
a wide range. The charged droplets apparently focused to the cotton yarn because when
the cotton yarn was immersed in the electrolyte solution, the cotton yarn became an
electric conductor and an electric field was formed between the nozzle and cotton
yarn.
<Example 2>
[0081] The lower end of a cotton yarn (material: cotton, thickness: No. 4 single yarn) with
a total length of 2 m or more which was manufactured by ASAHIBO CO., LTD. was fixed
to a winding roll, and the cotton yarn, electrospray sprayer, immersion liquid tank,
and electrodes for voltage application, etc., were disposed as shown in the conceptual
diagram in Fig. 5 (in Fig. 5, the reference numeral 501 stands for a cotton yarn,
502 - an electrospray sprayer, 503 - a sprayed dye solution, 504 - a sodium carbonate
solution, 505 - an immersion liquid tank, 506 - a roller, 507 - electrodes for voltage
application, and 508 - a winding roll). A stainless steel nozzle with an opening diameter
of the spraying port of 0.1 mm was used for the electrospray sprayer. The cotton yarn
was then positioned on the spraying direction (horizontal direction) of the nozzle,
and the nozzle tip and cotton yarn were fixed such that the shortest distance therebetween
was 30 mm. The electrospray sprayer was loaded with a dye solution (Remazol RED RU-N,
concentration: 0.5% by mass, manufactured by DyStar Japan Ltd.).
[0082] In the present arrangement, the preparation step in which the cotton yarn is immersed
in the electrolyte solution and the spraying step in which the dye solution is sprayed
toward the cotton yarn with the electrospray sprayer are performed continuously by
winding the cotton yarn. The preparation step and spraying step will be described
hereinbelow in greater detail.
(Preparation step)
[0083] An aqueous solution of sodium carbonate (concentration: 5% by mass) was loaded into
the immersion liquid tank. The cotton yarn was immersed for about 5 sec into the aqueous
solution of sodium carbonate, and the cotton yarn was then wound such as to move to
the spray target for the electrospray sprayer (the content of the aqueous solution
of sodium carbonate on the cotton yarn: 400% by mass).
(Spraying step)
[0084] The loaded dye solution was sprayed from the electrospray sprayer toward the cotton
yarn which passed through the aqueous solution of sodium carbonate. The spraying was
performed by applying 5.0 kV to the nozzle electrode and grounding the cotton yarn.
A photograph illustrating the state of spraying the dye solution is shown in Fig.
6.
[0085] As clearly follows from Fig. 6, the dye solution sprayed from the electrospray sprayer
was focused to the cotton yarn. Droplets that deviated from the cotton yarn were also
focused to the cotton yarn such as to be guided by and comprised in the electric field.
The dye solution utilization efficiency was calculated from the results obtained in
measuring the mass and concentration of the sprayed dye solution and the concentration
of the dye eluate from the dyed yarn. The calculation result indicated that 37% by
mass of the dye solution was used for application to the cotton yarn. Further, the
droplets scattered without focusing could be collected behind the fiber material,
and the amount thereof could be incinerated.
<Example 3>
[0086] A cotton yarn was dyed by spraying a dyeing solution in the same manner as in Example
2, except that dyeing solutions of two types were continuously sprayed using two electrospray
sprayers as in the conceptual diagrams shown in Figs. 7(A) and 7(B) (in Fig. 7(A)
and Fig. 7(B), the reference numeral 701 stands for a cotton yarn, 702 - an electrospray
sprayer, 703 - a sprayed dye solution, 704 - an electrospray sprayer, 705 - a sprayed
dye solution, 706 - a sodium carbonate solution, 707 - an immersion liquid tank, 708
- a roller, 709 - electrodes for voltage application, and 710 - a winding roll). A
photograph illustrating the state of spraying the dye solution is shown in Fig. 7(C).
[0087] As clearly follows from Fig. 8, by using two or more electrospray sprayers, multicolor
dyeing can be performed continuously with respect to one cotton yarn, and the processing
such as gradation dyeing can be performed by adjusting the applied potential and the
feed rate of the cotton yarn.
<Comparative Example 2>
[0088] A dye solution was sprayed toward a cotton yarn from an electrospray sprayer by the
same method as in Example 2, except that the cotton yarn was not immersed in the solution
of sodium carbonate (concentration: 5.0% by mass). A photograph illustrating the state
of spraying the dye solution is shown in Fig. 9. When the cotton yarn was not immersed
in the electrolyte solution, the dye solution sprayed from the electrospray sprayer
diffused within a wide range and could not be sufficiently supplied to the cotton
yarn.
<Example 4>
[0089] The lower end of a cotton yarn (material: cotton, thickness: No. 4 single yarn) with
a total length of 2 m or more which was manufactured by ASAHIBO CO., LTD. was fixed
to a winding roll, and the cotton yarn, electrospray sprayer, and immersion liquid
tank, etc. were disposed as shown in the conceptual diagram in Fig. 10 (in Fig. 10,
the reference numeral 1001 stands for a cotton yarn, 1002 - an electrospray sprayer,
1003 - a sprayed aqueous solution of silver nitrate, 1004 - an aqueous solution of
ascorbic acid, 1005 - an immersion liquid tank, 1006 - a roller, 1007 - electrodes
for voltage application, and 1008 - a winding roll). A stainless steel nozzle with
an opening diameter of the spraying port of 0.1 mm was used for the electrospray sprayer.
The cotton yarn was then positioned on the spraying direction (horizontal direction)
of the nozzle, and the nozzle tip and cotton yarn were fixed such that the shortest
distance therebetween was 20 mm. The electrospray sprayer was loaded with a silver
nitrate solution (silver ion concentration: 0.1 mol/L, solvent: ethanol/water = 4/1
(volume ratio)).
[0090] In the present arrangement, the preparation step in which the cotton yarn is immersed
in the electrolyte solution and the spraying step in which the aqueous solution of
silver nitrate is sprayed toward the cotton yarn with the electrospray sprayer are
performed continuously by winding the cotton yarn. The preparation step and spraying
step will be described herein below in greater detail.
(Preparation step)
[0091] An ascorbic acid solution (ascorbic acid concentration: 0.1 mol/L, solvent: ethanol/water
= 4/1 (volume ratio)) was loaded into the immersion liquid tank. The cotton yarn was
immersed for about 2 sec into the aqueous solution of ascorbic acid, and the cotton
yarn was then wound such as to move to the spray target for the electrospray sprayer
at a rate of 1 m/min (the content of the aqueous solution of ascorbic acid on the
cotton yarn: 400% by mass).
(Spraying step)
[0092] The loaded aqueous solution of silver nitrate was sprayed from the electrospray sprayer
toward the cotton yarn which has passed through the solution of ascorbic acid. The
spraying was performed by applying +6.0 kV to the nozzle electrode and -3.0 kV to
the cotton yarn (reference potential: ground).
[0093] The cotton yarn subjected to spraying was recovered, washed with water (conditions:
12 yards of the cotton yarn was picked up and then washed with water while introducing
into a pot of a dyeing testing device and rotating therein; cotton yarn : water =
1 : 20) in the device depicted in Fig. 11 and dried (conditions: constant-temperature
drying at 60°C) (in Fig. 11, the reference numeral 1111 stands for a processed yarn,
1112 - a cotton yarn (for bath ratio adjustment), 1113 - a pot, 1114 - a sample fixing
fixture, 1115 - washing water, and 1116 - hot solution (ethylene glycol)).
[0094] The photographs of the cotton yarn taken before and after the spraying are shown
in Fig. 12(A), and the scanning electron micrograph of the cotton yarn taken after
the spraying is shown in Fig. 12(B). As a result of impregnation with metallic silver
particles, the cotton yarn is colored black, and it is clear that fine particles have
been applied to the cotton yarn surface.
[0095] Further, silver was eluted from the cotton yarn with 1 N nitric acid, and the eluate
was measured with an atomic absorption spectrometer. Silver ions were detected and
it was confirmed that metallic silver was formed on the cotton yarn surface.
[0096] Thus, it was made clear that when the fiber material comprises a reducing agent (also
acts as an electrolyte), such as ascorbic acid, and the coating material comprising
metal ions, such as a silver nitrate solution, is sprayed, it is possible to generate
metal particles in the fiber material.
<Impregnation capacity evaluation test for metallic silver particles>
[0097] Cotton yarns impregnated with metallic silver particles were prepared by the same
method as in Example 4, except that the feed rate (winding rate) of the cotton yarn
was changed, and the impregnated amount of the metallic silver particles was measured
before and after washing with water. The impregnated amount of the metallic silver
particles was determined by eluting silver with nitric acid and measuring the amount
of silver ions in the solution with an atomic absorption spectrometer in the same
manner as in Example 4. Fig. 14 shows the graph representing the relationship between
the feed rate of the cotton yarn and the impregnated amount of the metallic silver
particles. The impregnated amount of the metallic silver particles tends to decrease
with the increase in the feed rate of the cotton yarn, but since the difference between
the impregnated amount of the metallic silver particles before and after washing with
water decreases, it can be supposed that the impregnation with excess metallic silver
particles which can easily fall from the yarn is suppressed and that securely impregnated
metallic silver particles are selectively formed. Further, it is clear that by using
the application method of the present invention it is possible to impregnate the fiber
material securely with the metallic silver particles, without using a binder (binding
agent, joining agent). When a binder suitable for surface processing of fiber material
is used, since the exposed surface area of the substance to be affixed, such as metallic
silver particles, decreases, the effect thereof is considered to weaken. By contrast,
since the application method of the present invention enables the "binder-free" application,
it is possible to manufacture a fiber material with excellent antibacterial ability.
<Antibacterial ability evaluation test>
[0098] The antibacterial ability of the cotton yarn impregnated with metallic silver particles
of Example 4 was evaluated. The antibacterial activity was evaluated by a method conforming
to JIS L1902 (Bacterial liquid absorption methods). Staphylococcus aureus IFO12732
was used as bacteria.
[0099] More specifically, the cotton yarn, 0.15 g, was placed in a vial, and a test bacterial
solution, 0.2 ml, was inoculated and cultured for 18 h at 35°C. The bacteria were
then washed out from the cotton yarn by adding sterile water, 10 ml, the number of
bacteria in the washout solution was measured by an emission measurement method (ATP
method), and the bacteriostatic activity value and bactericidal activity value were
calculated by the following formulas:

[0100] The bacteriostatic activity value is the logarithmic representation of a value obtained
by dividing the number of viable bacteria in the standard yarn after culturing for
18 h by the number of viable bacteria in the processed yarn after culturing for 18
h. Where the bacteriostatic activity value is 2.0 or more, it is assumed that the
antibacterial/deodorizing effect is demonstrated. The bactericidal activity value
is the logarithmic representation of a value obtained by dividing the number of viable
bacteria in the standard yarn immediately after the inoculation by the number of viable
bacteria in the processed yarn after culturing for 18 h. Where the antibacterial activity
value is 0 or more, it is assumed that the antibacterial effect is demonstrated.
[0101] The results are shown in Table 1. The results obtained with the cotton yarn for which
the feed rate (winding rate) of the cotton yarn was changed from 1 m/min to 2 m/min
(Example 5) and for the standard cotton yarn that has not been impregnated with the
metallic silver particles (Comparative Example 3) are also shown in Table 1.
[0102] The results clearly indicate that the cotton yarn impregnated with the metallic silver
particles excels in antibacterial ability.
Table 1
| |
Feed rate of cotton yarn |
Number of viable bacteria |
[CFU/ml] |
Bacteriostatic activity value |
Bactericidal activity value |
| Number of inoculated bacteria |
After 18 h |
| Example 4 |
1 m/min |
3.1×105 |
0.59×105 |
2.07 |
0.72 |
| Example 5 |
2 m/min |
3.1×105 |
0.38×105 |
2.26 |
0.91 |
| Comparatives Example 3 |
Standard cotton yarn |
3.1×105 |
6.9×106 |
|
|
<Example 6 (plant dyeing)>
[0103] The lower end of a silk yarn (material: silk, thickness: 120 Nm double-yarn) with
a total length of 2 m or more which was manufactured by Jiangsu Spcc Silk Group Co.,
Ltd. was fixed to a winding roll, and the silk yarn, electrospray sprayer, immersion
liquid tank, etc., were disposed as shown in the conceptual diagram in Fig. 15(A)
(in Fig. 15(A), the reference numeral 1501 stands for a silk yarn, 1502 - an electrospray
sprayer, 1503 - a sprayed dye solution, 1504 - an electrolyte solution, 1505 - an
immersion liquid tank, 1506 - a roller, 1507 - electrodes for voltage application,
and 1508 - a winding roll). An electrospray sprayer had a nozzle in the form of a
glass capillary (opening diameter 0.1 mm) with an electrode attached to the tip thereof.
The silk yarn was positioned on the spraying direction (horizontal direction) of the
nozzle, and the nozzle tip and silk yarn were fixed such that the shortest distance
therebetween was 20 mm. The electrospray sprayer was loaded with a liquid plant dye
(sappanwood solution, sophora solution (TANAKANAO SENRYOTEN)), liquid plant dye :
ethanol/water = 1/1 (volume ratio)).
[0104] A mordant solution (aqueous solution of potassium alum or iron (II) sulfate; concentration:
1% by mass) was loaded into the immersion liquid tank. The silk yarn was immersed
for about 2 sec into the mordant solution, and the silk yarn was then wound at a rate
of 1 m/min such as to move to the spray target for the electrospray sprayer (the content
of the mordant solution in the silk yarn: 400% by mass).
[0105] The liquid plant dye was sprayed from the electrospray sprayer toward the silk yarn
which passed through the mordant solution. The spraying was performed by applying
+5.0 kV to the nozzle electrode and -3.0 kV to the silk yarn (reference potential:
ground).
[0106] The silk yarn subjected to spraying was recovered, baked for 5 min at 90°C, washed
with water (conditions: 12 yards of the silk yarn was picked up and then washed with
water while introducing into a pot of a dyeing testing device and rotating therein:
silk yarn : water = 1 : 20) in the device depicted in Fig. 11 and dried (conditions:
constant-temperature drying at 60°C). A photograph of the silk yarn is shown in Fig.
15(B).
<Example 7 (gradation dyeing (cotton))>
[0107] The lower end of a cotton yarn (material: cotton, thickness: No. 20 single yarn)
with a total length of 2 m or more which was manufactured by ASAHIBO CO., LTD. was
fixed to a winding roll, and the cotton yarn, electrospray sprayer, and immersion
liquid tank, etc. were disposed as shown in the conceptual diagram in Fig. 16(A) (in
Fig. 16(A), the reference numeral 1601 stands for a cotton yarn, 1602 - an electrospray
sprayer, 1603 - a sprayed dye solution, 1604 - an electrolyte solution, 1605 - an
immersion liquid tank, 1606 - a roller, 1607 - electrodes for voltage application,
1608 - a winding roll, and 1609 - a filter paper shutter). Each of three electrospray
sprayers had a nozzle in the form of a glass capillary (opening diameter 0.1 mm) with
an electrode attached to the tip thereof. The cotton yarns were positioned in parallel
on the spraying direction (horizontal direction) of the nozzle, and the nozzle tip
and cotton yarns were fixed such that the shortest distance therebetween was 20 mm.
Three electrospray sprayers were loaded with dye solutions of three colors (Remazol
RED RU-N, concentration: 5% by mass, Remazol BLUE RU-N, concentration: 5% by mass,
Remazol YELLOW RU-N, concentration: 5% by mass; manufactured by DyStar Japan Ltd.).
The spray of the dyes from the electrospray sprayers was cut off with the filter paper
shutter to obtain color gradation.
[0108] In the present arrangement, the preparation step in which the cotton yarn is immersed
in the electrolyte solution and the spraying step in which the dye solutions are sprayed
toward the cotton yarn with the electrospray sprayers are performed continuously by
winding the cotton yarn. The preparation step and spraying step will be described
hereinbelow in greater detail.
(Preparation step)
[0109] An aqueous solution of sodium carbonate (concentration: 5% by mass) was loaded into
the immersion liquid tank. The cotton yarn was immersed for about 5 sec into the aqueous
solution of sodium carbonate, and the cotton yarn was then wound such as to move to
the spray target for the electrospray sprayer (the content of the aqueous solution
of sodium carbonate on the cotton yarn: 400% by mass).
(Spraying step)
[0110] The loaded dye solutions of three colors were successively sprayed from the electrospray
sprayers toward the cotton yarn which passed through the aqueous solution of sodium
carbonate. The spraying was performed by applying +4.0 kV to the nozzle electrode
and -3.7 kV to the cotton yarn. A photograph of the cotton yarn is shown in Fig. 16(B).
<Example 8 (gradation dyeing (silk))>
[0111] The lower end of a silk yarn (material: silk, thickness: 120 Nm double-yarn) with
a total length of 2 m or more which was manufactured by Jiangsu Spcc Silk Group Co.,
Ltd. was fixed to a winding roll, and the silk yarn, electrospray sprayer, immersion
liquid tank, etc., were disposed as shown in the conceptual diagram in Fig. 17(A)
(in Fig. 17(A), the reference numeral 1701 stands for a silk yarn, 1702 - an electrospray
sprayer, 1703 - a sprayed dye solution, 1704 - an electrolyte solution, 1705 - an
immersion liquid tank, 1706 - a roller, 1707 - electrodes for voltage application,
1708 - a winding roll, and 1709 - a filter paper shutter). The three electrospray
sprayers each had a nozzle in the form of a glass capillary (opening diameter 0.1
mm) with an electrode attached to the tip thereof. The silk yarns were positioned
in parallel on the spraying direction (horizontal direction) of the nozzle, and the
nozzle tip and cotton yarns were fixed such that the shortest distance therebetween
was 20 mm. The three electrospray sprayers were loaded with dye solutions of three
colors (Kayanol Milling Blue BW, concentration: 1% by mass, Kayanol Milling Red 3BW,
concentration: 1% by mass, Kayanol Milling YELLOW BW, concentration: 1% by mass; manufactured
by Nippon Kayaku Co., Ltd.). The spray of the dyes from the electrospray sprayers
was cut off with the filter paper shutter to obtain color gradation.
[0112] In the present arrangement, the preparation step in which the silk yarn is immersed
in the electrolyte solution and the spraying step in which the dye solutions are sprayed
toward the silk yarn with the electrospray sprayers are performed continuously by
winding the cotton yarn. The preparation step and spraying step will be described
hereinbelow in greater detail.
(Preparation step)
[0113] An aqueous solution of ammonium acetate (concentration: 0.01 M) was loaded into the
immersion liquid tank. The silk yarn was immersed for about 5 sec into the aqueous
solution of ammonium acetate, and the silk yarn was then wound such as to move to
the spray target for the electrospray sprayer (the content of the aqueous solution
of ammonium acetate on the cotton silk: 400% by mass).
(Spraying step)
[0114] The loaded dye solutions of three colors were successively sprayed from the electrospray
sprayers toward the silk yarn which has passed through the aqueous solution of ammonium
acetate. The spraying was performed by applying +4.0 kV to the nozzle electrode and
-3.7 kV to the silk yarn. A photograph of the silk yarn is shown in Fig. 17(B).
<Example 9 (dark dyeing)>
[0115] The lower end of a cotton yarn (material: cotton, thickness: No. 20 single yarn)
with a total length of 2 m or more which was manufactured by ASAHIBO CO., LTD. was
fixed to a winding roll, and the cotton yarn, electrospray sprayer, and immersion
liquid tank, etc. were disposed as shown in the conceptual diagram in Fig. 18(A) (in
Fig. 18(A), the reference numeral 1801 stands for a cotton yarn, 1802 - an electrospray
sprayer, 1803 - a sprayed dye solution, 1804 - an electrolyte solution, 1805 - an
immersion liquid tank, 1806 - a roller, 1807 - electrodes for voltage application,
and 1808 - a winding roll). The three electrospray sprayers each had a nozzle in the
form of a glass capillary (opening diameter 0.1 mm) with an electrode attached to
the tip thereof. The cotton yarns were positioned in parallel on the spraying direction
(horizontal direction) of the nozzle, and the nozzle tip and cotton yarns were fixed
such that the shortest distance therebetween was 20 mm. The three electrospray sprayers
were all loaded with the same dye solution (Remazol RED RU-N, concentration: 5% by
mass; manufactured by DyStar Japan Ltd.).
[0116] In the present arrangement, the preparation step in which the cotton yarn is immersed
in the electrolyte solution and the spraying step in which the dye solutions are sprayed
toward the cotton yarn with the electrospray sprayers are performed continuously by
winding the cotton yarn. The preparation step and spraying step will be described
hereinbelow in greater detail.
(Preparation step)
[0117] An aqueous solution of sodium carbonate (concentration: 5% by mass) was loaded into
the immersion liquid tank. The cotton yarn was immersed for about 5 sec into the aqueous
solution of sodium carbonate, and the cotton yarn was then wound such as to move to
the spray target for the electrospray sprayer (the content of the aqueous solution
of sodium carbonate on the cotton yarn: 400% by mass).
(Spraying step)
[0118] The loaded dye solutions were successively sprayed from the electrospray sprayers
toward the cotton yarn which passed through the aqueous solution of sodium carbonate.
The spraying was performed by applying +4.0 kV to the nozzle electrode and -3.2 kV
to the cotton yarn. A photograph of the cotton yarn is shown in Fig. 18(B).
<Example 10 (paper yarn dyeing)>
[0119] The lower end of a paper yarn (material: paper, thickness: 41 Nm single yarn) with
a total length of 2 m or more which was manufactured by DAIGO FIBER LTD. was fixed
to a winding roll, and the paper yarn, electrospray sprayer, immersion liquid tank,
etc. were disposed as shown in the conceptual diagram in Fig. 5 (in Fig. 5, the reference
numeral 501 stands for a cotton yarn, 502 - an electrospray sprayer, 503 - a sprayed
dye solution, 504 - a sodium carbonate solution, 505 - an immersion liquid tank, 506
- a roller, 507 - electrodes for voltage application, and 508 - a winding roll). The
electrospray sprayer had a nozzle in the form of a glass capillary (opening diameter
0.1 mm) with an electrode attached to the tip thereof. The paper yarns were positioned
in parallel on the spraying direction (horizontal direction) of the nozzle, and the
nozzle tip and paper yarns were fixed such that the shortest distance therebetween
was 20 mm. The electrospray sprayer was loaded with a dye solution (Remazol RED RU-N,
concentration: 5% by mass, manufactured by DyStar Japan Ltd.).
[0120] In the present arrangement, the preparation step in which the paper yarn is immersed
in the electrolyte solution and the spraying step in which the dye solution is sprayed
toward the paper yarn with the electrospray sprayer are performed continuously by
winding the paper yarn. The preparation step and spraying step will be described hereinbelow
in greater detail.
(Preparation step)
[0121] An aqueous solution of sodium carbonate (concentration: 5% by mass) was loaded into
the immersion liquid tank. The paper yarn was immersed for about 5 sec into the aqueous
solution of sodium carbonate, and the paper yarn was then wound such as to move to
the spray target for the electrospray sprayer (the content of the aqueous solution
of sodium carbonate on the paper yarn: 400% by mass).
(Spraying step)
[0122] The loaded dye solution was sprayed from the electrospray sprayer toward the paper
yarn which passed through the aqueous solution of sodium carbonate. The spraying was
performed by applying 5.0 kV to the nozzle electrode and grounding the paper yarn.
A photograph of the paper yarn is shown in Fig. 19.
[0123] Photographs of cotton yarn dyed using other reactive dyes are shown in Fig. 20. The
application method of the present invention is clearly suitable for dyeing various
fiber materials such as cotton, silk, and paper. The application method can be also
used with various types of dyes.
INDUSTRIAL APPLICABILITY
[0124] The application method of the present invention enables efficient application of
a coating material to a fiber material such as yarns, woven fabrics, nonwoven fabrics,
and paper. Therefore, the application method can be used for dyeing, antibacterial/deodorizing
treatment, water and oil repelling treatment, flame retardant treatment, bleaching
treatment, softening treatment, and the like.
REFERENCE SIGNS LIST
[0125]
101 fiber material comprising an electrolyte solution
102 nozzle of electrospray sprayer
103 sprayed coating material
104 distance between the nozzle of the electrospray sprayer and the fiber material
201 fiber material comprising an electrolyte solution
202 electrospray sprayer
203 sprayed coating material
204 sprayed coating material of a type different from that of 203
301 fiber material
302 roller
303 electrospray sprayer
304 sprayed coating material
305 immersion liquid tank
306 electrolyte solution
307 spraying device for spraying an electrolyte solution
308 sprayed electrolyte solution
309 dropping device
310 dropped electrolyte solution
501 cotton yarn
502 electrospray sprayer
503 sprayed dye solution
504 sodium carbonate solution
505 immersion liquid tank
506 roller
507 electrode for voltage application
508 winding roll
701 cotton yarn
702 electrospray sprayer
703 sprayed dye solution
704 electrospray sprayer
705 sprayed dye solution
706 sodium carbonate solution
707 immersion liquid tank
708 roller
709 electrode for voltage application
710 winding roll
1001 cotton yarn
1002 electrospray sprayer
1003 sprayed aqueous solution of silver nitrate
1004 aqueous solution of ascorbic acid
1005 immersion liquid tank
1006 roller
1007 electrode for voltage application
1008 winding roll
1111 processed yarn
1112 cotton yarn (for bath ratio adjustment)
1113 pot
1114 sample fixing fixture
1115 water for washing
1116 hot solution (ethylene glycol)
1301 fiber material before processing
1302 tank containing electrolyte solution
1303 dyeing treatment step
1304 functional material addition (antibacterial/deodorizing treatment) step
1305 sizing step
1306 electrospray sprayer
1307 heating and drying device
1501, 1701 silk yarns
1502, 1602, 1702, 1802 electrospray sprayers
1503, 1603, 1703, 1803 sprayed dye solutions
1504, 1604, 1704, 1804 electrolyte solutions
1505, 1605, 1705, 1805 immersion liquid tanks
1506, 1606, 1706, 1806 rollers
1507, 1607, 1707, 1807 electrodes for voltage application
1508, 1608, 1708, 1808 winding rolls
1601, 1801 cotton yarns
1609, 1709 filter paper shutters.