Note: Descriptions are shown in the official language in which they were submitted.
CA 02737687 2011-03-17
DESCRIPTION
Title of Invention: WATERPROOF SOUND-PERMEABLE HOOD
Technical Field
[0001]
The present invention relates to a waterproof sound-permeable hood having
excellent waterproofness and excellent sound permeability.
Background Art
[0002]
Conventionally, rainwears to be used in daily life or for work, such as
raincoats and rain jackets, are each provided with a waterproof hood for
preventing
the head of a wearer from becoming wet with raindrops or the like. Such a
waterproof hood is formed of a waterproof material such as a waterproof fabric
or a
waterproof sheet. However, when a hole or break occurs in the waterproof
material
by, for example, abrasion while wearing or stress during washing, the
waterproofness
of the waterproof hood becomes lost. Therefore, in view of improving the
durability
against, for example, abrasion while wearing, a material obtained by the
waterproof
treatment of a relatively thick fabric of polyamide, polyester, or any other
resin is
often used as a waterproof material forming a waterproof hood.
[0003]
In the meantime, a waterproof hood usually has such a structure as to cover
the head (the parietal region, the temporal region, and the occipital region)
of a
wearer. Therefore, when a waterproof hood is worn, the waterproof hood also
covers
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both ears of the wearer. In addition, as described above, a waterproof hood is
often
formed of a relatively thick waterproof material. However, such a waterproof
hood
formed of a relatively thick waterproof material has a very low sound
permeability.
Therefore, when a waterproof hood is worn, ambient sounds are difficult to
hear,
which causes the following problems. For example, the wearer may have
difficulty
in making a conversation while wearing the waterproof hood. Alternatively, the
wearer may miss an alarm from a device or the like at a worksite.
[0004]
Thus, to improve sound permeability during wearing, various proposals have
been made for waterproof hoods having openings in positions respectively
corresponding to the ears of a wearer (e.g., Patent Documents 1 and 2).
However,
the waterproof hoods disclosed in Patent Documents 1 and 2 had a problem that
raindrops infiltrate through the openings.
Prior Art Documents
Patent Documents
[0005]
Patent Document 1: Japanese Utility Model Registration Publication No.
3054521
Patent Document 2: Japanese Patent Laid-open Publication No. 2002-275723
Summary of the Invention
Problems to be Solved by the Invention
[0006]
The present invention was completed in view of the above problems, and it is
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t
an object of the present invention to provide a waterproof sound-permeable
hood
having excellent waterproofness and excellent sound permeability.
Means of Solving the Problems
[0007]
The waterproof sound-permeable hood of the present invention, which can
solve the above problems, is formed of a waterproof material, which hood
comprises
a waterproof sound-permeable means provided on at least one of portions
respectively facing to the ears of a wearer who wears the waterproof material,
wherein the waterproof sound-permeable means comprises a waterproof sound-
permeable membrane having a sound-transmission loss of not greater than 5 db.
The
use of a waterproof sound-permeable membrane having a sound-transmission loss
of
not greater than 5 db as the waterproof sound-permeable means makes it
possible to
improve the waterproofness of a waterproof sound-permeable hood without
deteriorating the sound permeability of the waterproof sound-permeable hood.
[0008]
As the waterproof sound-permeable membrane, there may be preferred those
which have at least one porous polytetrafluoroethylene layer. In addition, as
the
waterproof sound-permeable membrane, there can also be used those which are
obtained by the water-repellant treatment of nonwoven fabrics, meshes, and any
other materials so as to have waterproofness.
[0009]
The waterproof sound-permeable means may preferably have at least one
protective layer to protect the waterproof sound-permeable membrane. In
addition,
the at least one protective layer may preferably be firmly attached to the
waterproof
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sound-permeable membrane.
[0010]
In the waterproof sound-permeable hood of the present invention, one
embodiment may be preferred in which the waterproof sound-permeable means
comprises a holing member having a cylindrical swaging part and a holding part
formed on one end of the cylindrical swaging part and wherein the holding
member
holds the waterproof sound-permeable membrane in the holding part and is fixed
to
the waterproof material by the cylindrical swaging part. The holding member
may
preferably have a gap between the waterproof sound-permeable membrane and the
holding part, which gap is sealed with a sealing member.
Effects of the Invention
[0011]
According to the present invention, a waterproof sound-permeable hood
having excellent waterproofness and excellent sound permeability can be
obtained.
Brief Description of the Drawings
[0012]
[FIG. 1 ]
This is a perspective view showing one embodiment of the waterproof sound-
permeable hood, of which waterproof sound-permeable means has a holding
member.
[FIG. 2]
This is a side view of the waterproof hood shown in FIG. 1.
[FIG. 3]
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This is a sectional view of the holding member.
[FIG. 4]
This is a perspective view of the holding member.
[FIG 5]
This is a sectional view of the holding member fixed to the waterproof
material.
[FIG. 6]
This is a perspective view showing another embodiment of the waterproof
sound-permeable hood, of which waterproof sound-permeable means does not have
a
holding member.
[FIG. 7]
This is a side view of the waterproof sound-permeable hood shown in FIG 6.
Mode for Carrying Out the Invention
[0013]
The following will describe one embodiment of the waterproof sound-
permeable hood of the present invention by reference to the drawings. FIG. 1
is a
perspective view showing one embodiment of the waterproof sound-permeable
hood,
of which waterproof sound-permeable means has a holding member. FIG. 2 is a
side
view of the waterproof sound-permeable hood shown in FIG. 1.
[0014]
As shown in FIGS. 1 and 2, the waterproof sound-permeable hood of the
present invention is formed of a waterproof material, which hood comprises a
waterproof sound-permeable means provided on at least one of portions
respectively
facing to the ears of a wearer who wear the waterproof material, wherein the
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waterproof sound-permeable means comprises a waterproof sound-permeable
membrane having a sound-transmission loss of not greater than 5 db.
[0015]
Waterproof Sound-Permeable Means
The waterproof sound-permeable means to be used in the present invention is
not particularly limited, so long as the waterproof sound-permeable means has
a
waterproof sound-permeable membrane having a sound-transmission loss of not
greater than 5 db. As the embodiment of the waterproof sound-permeable means
to
be used in the present invention, there can be mentioned an embodiment in
which the
waterproof sound-permeable means is formed only of a waterproof sound-
permeable
membrane; an embodiment in which the waterproof sound-permeable means is
formed of a waterproof sound-permeable membrane and a protective layer to
protect
the waterproof sound-permeable membrane; and an embodiment in which the
waterproof sound-permeable means is formed of a waterproof sound-permeable
membrane and a holding member described later.
[0016]
Waterproof Sound-Permeable Membrane
The following will describe a waterproof sound-permeable membrane having
a sound-transmission loss of not greater than 5 db, which membrane is used for
the
waterproof sound-permeable means (the membrane may hereinafter be referred to
simply as a "waterproof sound-permeable membrane").
[0017]
The waterproof sound-permeable membrane has a sound-transmission loss of
not greater than 5 db, preferably not greater than 3 db, and more preferably
not
greater than 1 db. When the sound-transmission loss is greater than 5 db, the
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waterproof sound-permeable means has an increased sound-transmission loss, and
therefore, a waterproof sound-permeable hood having excellent sound
permeability
cannot be obtained. The lower limit of the sound-transmission loss of the
waterproof
sound-permeable membrane is not particularly limited, but is, of course,
greater than
0 db. There will be described later about the method of measuring the sound-
transmission loss of the waterproof sound-permeable membrane in the present
invention.
[0018]
The mass per unit area of the waterproof sound-permeable membrane, for
example, when a single-layer membrane of porous polytetrafluoroethylene as
described later is used as the waterproof sound-permeable membrane, may
preferably
be not smaller than 0.5 g/m2, more preferably not smaller than 1.0 g/m2, and
still
more preferably not smaller than 2.0 g/m2, but may preferably be not greater
than 20
g/m2, more preferably not greater than 10 g/m2, and still more preferably not
greater
than 5 g/m2. When the mass per unit area of the waterproof sound-permeable
membrane is smaller than 0.5 g/m2, a problem may arise with handleability
during
the production of the waterproof sound-permeable membrane. When the mass per
unit area of the waterproof sound-permeable membrane is greater than 20 g/m2,
the
sound permeability of the waterproof sound-permeable means has a tendency to
be
decreased. The mass per unit area of the waterproof sound-permeable membrane
is
determined by, for example, cutting the waterproof sound-permeable membrane
into
a 10 cm square and measuring the mass of the square with a precision balance.
[0019]
The thickness of the waterproof sound-permeable membrane may preferably
be not smaller than 3 m, more preferably not smaller than 4 gm, and still
more
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preferably not smaller than 5 gm, but may preferably be not greater than 150
gm,
more preferably not greater than 33 gm, and still more preferably not greater
than 10
gm. When the thickness of the waterproof sound-permeable membrane is smaller
than 3 gm, a problem may arise with handleability during the production of the
waterproof sound-permeable membrane. When the thickness of the waterproof
sound-permeable membrane is greater than 150 gm, the sound permeability of the
waterproof sound-permeable means has a tendency to be decreased. The
measurement of the thickness of the waterproof sound-permeable membrane is
based
on the average thickness measured with a dial thickness gauge (the measurement
of
the average thickness was carried out using a 1/1000 mm dial thickness gauge,
available from Teclock Corporation, in the state where no load was applied
other
than the spring load of the gauge body).
[0020]
The waterproof sound-permeable membrane is not particularly limited, so
long as the sound-transmission loss is not greater than 5 db, but may be a
single-
layer membrane or a multi-layer membrane in which two or more layers are
laminated. As the material forming the waterproof sound-permeable membrane,
there can be mentioned many polymer materials including, for example, silicone
rubber; polyurethane; polyamide; polyester; polyolefin such as polyethylene
and
polypropylene; and fluoropolymer. As the fluoropolymer, there may be
preferred,
for example, polyfluorovinylidene (PVDF), tetrafluoroethylene-
hexafluoropropylene
copolymer (FEP), tetrafluoroethylene-(perfluoroalkyl)vinyl ether copolymer
(PFA),
and polytetrafluoroethylene (PTFE). In addition, as the waterproof sound-
permeable
membrane, there can also be used those which are obtained by the water-
repellant
treatment of nonwoven fabrics, meshes, and any other materials so as to have
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waterproofness.
[0021]
As the waterproof sound-permeable membrane to be used in the present
invention, there may be preferred those which have at least one layer of
porous
polytetrafluoroethylene (which may hereinafter be referred to as a "porous
PTFE
film"). In this case, as the waterproof sound-permeable membrane, there can be
used
a single-layer membrane formed only of a porous PTFE film layer, or a multi-
layer
membrane in which a porous PTFE film layer is laminated with a layer formed of
another material. Among these, a single-layer membrane formed only of a porous
PTFE film layer may be more preferred in view of the sound permeability of the
waterproof sound-permeable membrane.
[0022]
The porous PTFE film means one obtained by preparing a shaped material
from a paste obtained by mixing a fine powder of polytetrafluoroethylene
(PTFE)
with a forming aid; removing the forming aid from the shaped material; and
then
stretching the shaped material in planar form at high temperature and high
speed, and
therefore, the porous PTFE film has a porous structure. That is, the porous
PTFE
film is formed of nodes, which are aggregates of polytetrafluoroethylene
primary
particles connected to one another by minute crystal ribbons, and fibrils,
which are
bundles of fully elongated crystal ribbons pulled out from the primary
particles. The
spaces defined by the fibrils and the nodes connecting the fibrils become
pores. The
porosity, the maximum pore diameter, and any other properties, which are
described
later, of the porous PTFE film can be controlled by stretch ratio and any
other
factors.
[0023]
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The maximum pore diameter of the porous PTFE film may preferably be not
smaller than 0.01 gm, more preferably not smaller than 0.1 m, but may
preferably
be not greater than 15 m, more preferably not greater than 10 gm. When the
maximum pore diameter is smaller than 0.01 gm, it is difficult to produce the
porous
PTFE film. On the other hand, when the maximum pore diameter is greater than
15
gm, the waterproofness of the porous PTFE film has a tendency to be decreased,
and
the strength of the film also becomes decreased. Thus, it is likely to be
difficult to
handle the porous PTFE film in the subsequent steps such as lamination.
[0024]
The porosity of the porous PTFE film may preferably be not smaller than
50%, more preferably not smaller than 60%, but may preferably be not greater
than
98%, more preferably not greater than 95%. When the porosity of the porous
PTFE
film is not smaller than 50%, the sound permeability of the film can be
ensured.
When the porosity of the porous PTFE film is not greater than 98%, the
strength of
the film can be ensured.
[0025]
The maximum pore diameter of the porous PTFE film is the value measured
in accordance with the requirements ofASTM F-316. Using the apparent density
(p)
measured in accordance with the apparent density measurements of JIS K 6885,
the
porosity of the porous PTFE film is determined by calculation with the
following
formula, where the true density of the PTFE is regarded as being 2.2 g/cm3:
Porosity (%) = 100 x (2.2 - p)/2.2
[0026]
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The porous PTFE film may preferably have greater air permeability. When
expressed in the Gurley number, the air permeability of the porous PTFE film
may
preferably be not greater than 50 sec, more preferably not greater than 10
sec. When
the air permeability of the porous PTFE film is greater than 50 sec in the
Gurley
number, the sound permeability of the porous PTFE film becomes decreased. The
air
permeability (Gurley number) of the porous PTFE film is measured based on JIS
P
8117.
[0027]
When the porous PTFE film is used, the surfaces inside the pores of the
porous PTFE film may preferably be coated with a water- and oil-repellent
polymer.
The reason for this is as follows. If contaminants, such as machine oils,
beverages,
and laundry detergents, penetrate into, or are held in, the pores of the
porous PTFE
film, the contaminants become a cause to reduce the hydrophobicity of the
porous
PTFE film and to deteriorate the waterproofness of the porous PTFE film.
However,
the coating of the surfaces inside the pores of the porous PTFE film with a
water-
and oil-repellent polymer (which may hereinafter be referred to as a "coating
polymer") makes it possible to prevent contaminants, such as machine oils,
beverages, and laundry detergents, from penetrating into, or being held in,
the pores
of the porous PTFE film.
[0028]
As the coating polymer, there can be used, for example, a polymer having
fluorine-containing side chains. The details of such a polymer and a method
for the
combined use of the polymer in the porous PTFE film are disclosed in WO
94/22928
and other publications. An example thereof is shown below.
[0029]
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As the coating polymer, there can preferably be used a polymer having
fluorine-containing side chains (the fluorinated alkyl moiety thereof may
preferably
have from 6 to 16 carbon atoms), the polymer being obtained by polymerizing a
fluoroalkyl acrylate and/or a fluoroalkyl methacrylate, represented by the
following
general formula (1):
[0030]
[Chemical Formula 1]
0
11
CF3(CF2)õ-CH2CH2-O-C-CR=CH2 (1)
wherein n is an integer of from 3 to 13 and R is hydrogen or a methyl group.
[0031]
To coat the inside of the pores of the porous PTFE film with the polymer, an
aqueous micro-emulsion of the polymer (having an average particle diameter of
from
0.01 gm to 0.5 gm) is prepared using a fluorine-containing surfactant (e.g.,
ammonium perfluorooctanoate), and the inside of the pores of the porous PTFE
film
is impregnated with the aqueous micro-emulsion, followed by heating. As a
result of
the heating, the water and the fluorine-containing surfactant are removed, and
at the
same time, the polymer having fluorine-containing side chains is melted to
coat the
surfaces inside the pores of the porous PTFE film such that the continuous
pores are
maintained. Thus, a porous PTFE film having high water repellency and high oil
repellency can be obtained.
[0032]
Alternatively, as another coating polymer, there can be used, for example,
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"AF Polymer" available from E. I. du Pont de Nemours and Company, and "CYTOP
(registered trademark)" available from Asahi Glass Co., Ltd. To coat the
surfaces
inside the pores of the porous PTFE film with each polymer, the polymer may be
dissolved in an inert solvent, such as "FLUORINERT (registered trademark)"
available from 3M Company, and the porous PTFE film may be impregnated with
the resulting solution, and then, the solvent may be removed by evaporation.
[0033]
Protective Layer
The waterproof sound-permeable means to be used in the present invention
may preferably have at least one protective layer that protects the waterproof
sound-
permeable membrane. The inclusion of a protective layer makes it possible to
prevent an external force from being applied to the waterproof sound-permeable
membrane when the waterproof sound-permeable hood is used, thereby preventing
the waterproof sound-permeable membrane from being damaged. The waterproof
sound-permeable means may preferably have a protective layer on each side of
the
waterproof sound-permeable means.
[0034]
The protective layer is not particularly limited, so long as the protective
layer
does not deteriorate the effect of the present invention. As the protective
layer,
porous members, such as meshes, nets, foam rubbers, sponges, nonwoven fabrics,
woven fabrics, and knits, may be preferred because such porous members each
have
sufficient strength and also ensure the sound permeability of the waterproof
sound-
permeable means. Each of these porous member may preferably have through pores
of substantially the same shape, which though pores are formed uniformly
throughout the porous member. If through pores of substantially the same shape
are
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formed uniformly throughout the porous member, the sound permeability and the
strength are uniform throughout the porous member, and therefore, there can be
obtained a waterproof sound-permeable means having sound permeability and
strength, both of which are uniform throughout the waterproof sound-permeable
means.
[0035]
The thickness of the protective layer may preferably be not smaller than 10
gm, more preferably not smaller than 100 m, but may preferably be not greater
than
1,000 m, more preferably not greater than 500 m. When the thickness of the
protective layer is smaller than 10 m, a problem may arise with handleability
during
the production of the protective layer. When the thickness of the protective
layer is
greater than 1,000 pm, the sound permeability of the waterproof sound-
permeable
means becomes decreased. The method of measuring the thickness of the
protective
layer is the same as that of the waterproof sound-permeable membrane.
[0036]
When a porous member is used as the protective layer, the maximum pore
diameter of the protective layer may preferably be not smaller than 10 gm,
more
preferably not smaller than 100 m, but may preferably be not greater than 5
mm,
more preferably not greater than 1 mm. When the maximum pore diameter of the
protective layer is smaller than 10 gm, the sound permeability of the
waterproof
sound-permeable means may significantly be decreased. On the other hand, when
the maximum pore diameter of the protective layer is greater than 5 mm, the
open
pores may become so large that the protective effect on the waterproof sound-
permeable means cannot be obtained. The maximum pore diameter can be measured
using a microscope.
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[0037]
In addition, the porosity of the protective layer may preferably be not
smaller
than 10%, more preferably not smaller than 50%, but may preferably be not
greater
than 95%, more preferably not greater than 90%. When the porosity of the
protective layer is not smaller than 10%, the sound permeability of the
waterproof
sound-permeable means can be ensured. When the porosity of the protective
layer is
not greater than 90%, the strength of the protective layer can be ensured to
effectively protect the waterproof sound-permeable means. The porosity is
measured
in the same manner as described for the waterproof sound-permeable membrane.
[0038]
Examples of the material of the protective layer may include polyolefin resins
such as polyethylene and polypropylene; polyester resins such as polyethylene
terephthalate and polycarbonate; thermoplastic resins such as polyimide
resins; and
metals such as stainless steel. As described later, when the protective layer
is firmly
attached to the waterproof sound-permeable membrane, the material of the
protective
layer may preferably be a thermoplastic resin having a lower melting point
than that
of the waterproof sound-permeable membrane. This is because such a
thermoplastic
resin can be fusion-bonded to the waterproof sound-permeable membrane by
thermal
lamination, without using an adhesive.
[0039]
Specific examples by product name of the protective layer may include "Net
Eyelet #25" available from Morito Co., Ltd. In addition, specific examples by
product name of the protective layer to be brought in firm contact with the
waterproof sound-permeable membrane may include "Conwed (registered
trademark) Net XN6065" available from Nisseki Plasto Co., Ltd.
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[0040]
In the waterproof sound-permeable means to be used in the present invention,
the at least one protective layer may preferably be firmly attached to the
waterproof
sound-permeable membrane.
[00411
The waterproof sound-permeable membrane needs to be made thin to ensure
the sound permeability of the waterproof sound-permeable means. Thus, a
pinhole
or break may easily occur in the waterproof sound-permeable membrane by, for
example, stress during washing, and there is fear that the waterproofness of
the
waterproof sound-permeable membrane may be lost. Therefore, the at least one
protective layer may preferably be firmly attached to the waterproof sound-
permeable membrane to support the waterproof sound-permeable membrane. The
protective layer may be firmly attached to one side of the waterproof sound-
permeable membrane, or the protective layer may be firmly attached to each
side of
the waterproof sound-permeable membrane. In view of the sound permeability of
the waterproof sound-permeable means, the protective layer may preferably be
firmly attached to only one side of the waterproof sound-permeable membrane.
[0042]
The protective layer to be firmly attached to the waterproof sound-permeable
membrane may preferably be a net, a nonwoven fabric, or any other materials
formed
of a resin, in view of strength and fusion bondability. Examples of the resin
net may
include "Delnet (registered trademark) (integrally formed polypropylene
product)
RB0404-12P" available from DelStar Technologies, Inc. In addition, examples of
the resin nonwoven fabric may include "ECOOL (registered trademark) (polyester
nonwoven fabric) 3151A" available from Toyobo Co., Ltd., in view of, for
example,
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sound permeability.
[0043]
The method of firmly attaching the protective layer to the waterproof sound-
permeable membrane is not particularly limited, but examples thereof may
include
adhesion using an adhesive; and melt bonding by thermal lamination. When an
adhesive is used and a porous product is used as the waterproof sound-
permeable
membrane, the adhesive may block a large portion of the pores of the
waterproof
sound-permeable membrane, and there is fear that the sound permeability of the
waterproof sound-permeable means may significantly be decreased. However, if a
thermoplastic resin having a lower melting point than that of the waterproof
sound-
permeable membrane is used as the material of the protective layer and is
fusion-
bonded by thermal lamination, the number of the pores of the waterproof sound-
permeable membrane to be blocked by the thermoplastic resin can be reduced,
and
this prevents the sound permeability of the waterproof sound-permeable means
from
decreasing, which may be preferred.
[0044]
When the protective layer is firmly attached to the waterproof sound-
permeable membrane, the sound-transmission loss of the waterproof sound-
permeable membrane, to which the protective layer has been firmly attached
(which
may hereinafter be referred to as a "laminated waterproof sound-permeable
membrane"), may preferably be not greater than 5 db, more preferably not
greater
than 4 db, and still more preferably not greater than 3 db. When the sound-
transmission loss of the laminated waterproof sound-permeable membrane is
greater
5 db, the sound-transmission loss of the waterproof sound-permeable means is
increased, and therefore, a waterproof sound-permeable hood having excellent
sound
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permeability cannot be obtained. The method of measuring the sound-
transmission
loss of the laminated waterproof sound-permeable membrane in the present
invention
is the same as that of the waterproof sound-permeable membrane.
[0045]
Holding Member
In the waterproof sound-permeable hood of the present invention, there is a
preferred embodiment in which the waterproof sound-permeable means comprises a
holding member having a cylindrical swaging part and a holding part formed on
one
end of the cylindrical swaging part, and the holding member holds the
waterproof
sound-permeable membrane in the holding part and is fixed to the waterproof
material by the cylindrical swaging part.
[0046]
Referring to FIGS. 3 to 5, the following will describe one example of the
waterproof sound-permeable means using the holding member. FIG. 3 is a
sectional
view of the holding member. FIG. 4 is a perspective view of the holding
member.
FIG. 5 is a sectional view of the holding member fixed to the waterproof
material.
[0047]
Holding Member
The holding member 20 has a cylindrical swaging part 21 and a holding part
22 formed around one end of the cylindrical swaging part 21, the holding part
22
having such a large outer diameter as to correspond in size to the inward
folding
when supporting the waterproof sound-permeable membrane. In addition, in this
embodiment, the waterproof sound-permeable membrane 11 has protective layers
12a and 12b on the respective sides thereof such that the protective layer 12a
is
firmly attached to the waterproof sound-permeable membrane 11. As shown in
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FIGS. 3 and 4, after the waterproof sound-permeable membrane 11 and the
protective layers 12a and 12b are laminated on the holding part 22, the edge
of the
holding part 22 is folded inwardly. Thus, the edges of the waterproof sound-
permeable membrane 11 and the protective layers 12a and 12b are attached
together
so as to be sandwiched by the holding part 22.
[0048]
The material of the holding part 20 is not particularly limited, but examples
thereof may include metals such as brass, and resins.
[0049]
The inner diameter of the cylindrical swaging part is not particularly
limited,
but may preferably be not smaller than 3 mm, more preferably not smaller than
5
mm, and still more preferably not smaller than 8 mm, but may preferably not
greater
than 80 mm, more preferably not greater than 60 mm, and still more preferably
not
greater than 40 mm. When the inner diameter of the cylindrical swaging part is
set
to be not smaller than 3 mm and not greater than 80 mm, the sound permeability
of
the waterproof sound-permeable means can be ensured, and the attachment of the
cylindrical swaging part to the waterproof material becomes facilitated.
[0050]
In addition, as shown in FIG. 3, in the holding member 20, the gap between
the waterproof sound-permeable membrane 11 and the holding section 22 may
preferably be sealed with a sealing member 23.
[0051]
When the gap between the waterproof sound-permeable membrane and the
holding section 22 is sealed with the sealing member 23, the waterproof
performance
of the waterproof sound-permeable hood can further be improved. Examples of
the
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sealing member to be used for the sealing may include resins such as silicone
resins,
polyamide resins, polyester resins, polyvinyl acetate resins, and polyurethane
resins.
These resins can appropriately be used alone, or two or more kinds of these
resins
can also appropriately be used as a mixture.
[0052]
Then, as shown in FIG. 5, the holding member 20 is attached and fixed to a
waterproof material 2 by causing the cylindrical swaging part 21 to directly
break
through and penetrate the waterproof material 2, to which the holding member
20 is
to be attached; fitting a female ring 24 around the cylindrical swaging part
21
extending to the opposite side of the waterproof material 2, and then crushing
the end
of the cylindrical swaging part 21 by a pressing force from the inner
direction. The
use of the holding member in this manner makes it possible to form a sound-
permeable opening in the waterproof material and attach a waterproof sound-
permeable membrane to the waterproof material at one time, resulting in an
improvement of workability.
[0053]
Waterproof Sound-Permeable Hood
Referring to FIGS. 1 and 2, the following will describe the structure of the
waterproof sound-permeable hood of the present invention.
[0054]
The waterproof sound-permeable hood of the present invention is formed of a
waterproof material, and comprises a waterproof sound-permeable means provided
on at least one of portions respectively facing to the ears of a wearer who
wears the
waterproof material.
[0055]
CA 02737687 2011-03-17
The waterproof sound-permeable hood of the present invention may include
not only those which are used alone as hoods, but also those which have been
attached to rainwears such as rain jackets and raincoats, and those which are
attachable to and detachable from these rainwears.
[0056]
As shown in FIGS. 1 and 2, the waterproof sound-permeable hood 1 of the
present invention is formed of the waterproof material 2, and the main unit of
the
waterproof sound-permeable hood 1 has such a structure as to cover the head
(the
parietal region, the temporal region, and the occipital region) of a wearer.
The
structure of the main unit of the waterproof sound-permeable hood 1 is not
particularly limited, so long as the main unit of the waterproof sound-
permeable
hood 1 covers at least the head of a wearer. For example, the main unit of the
waterproof sound-permeable hood 1 may cover the cheeks or the neck of a
wearer.
Alternatively, the connecting portion between the main unit of the waterproof
sound-
permeable hood 1 and a rainwear, such as a rain jacket, may be formed in an
integrated manner.
[0057]
The waterproof material is not particularly limited, so long as it has
waterproofness, but examples thereof may include waterproof sheets formed of
resins or rubbers; waterproof fabrics obtained by impregnating fabrics, such
as
woven fabrics or knitted fabrics, with resins or rubbers; and waterproof
laminated
products having the lamination of a fabric such as a woven fabric or a knitted
fabric
with a sheet formed of a resin or a rubber. In view of improving the feel of
the
waterproof laminated product against the wearer's skin, the lamination may
preferably include a woven fabric or a knitted fabric as a lining. Among
these, the
21
CA 02737687 2011-03-17
s
waterproof material forming the waterproof sound-permeable hood of the present
invention may preferably have the lamination of a woven fabric, a waterproof
moisture-permeable membrane, and a lining, such that the woven fabric serves
as the
outer material and the main unit of the lamination.
[0058]
Examples of the resin and the rubber to be used for the waterproof sheet and
the waterproof fabric may include polyurethane resins; polyester resins such
as
polyethylene terephthalate and polybutyrene terephthalate; acrylic resins;
polyolefin
resins such as polyethylene and polypropylene; polyamide resins; vinyl
chloride
resins; synthetic rubbers; natural rubbers; and fluorine-containing resins.
[0059]
In addition, the fibers forming the woven fabric and the knitted fabric may be
either natural fibers or synthetic fibers. Examples of the natural fibers may
include
plant fibers such as cotton and linen; and animal fibers such as silk, wool,
and any
other animal hairs. In addition, examples of the synthetic fibers may include
polyamide fibers; polyester fibers; and acrylic fibers. In particular, when
the fibers
are used for clothing or any other products, polyamide fibers, polyester
fibers, and
any other fibers may be preferred in view of characteristics such as
flexibility,
strength, durability, cost, and lightweightness.
[0060]
In addition, in a preferred embodiment of the waterproof laminated product
having the lamination of a fabric such as a woven fabric or a knitted fabric
with a
sheet formed of a resin or a rubber, a waterproof moisture-permeable sheet is
used as
the waterproof sheet included in the waterproof laminated product. The
waterproof
moisture-permeable sheet is a flexible sheet having "waterproofness" and
"moisture
22
CA 02737687 2011-03-17
permeability." That is, the waterproof laminated product can be provided with
"moisture permeability" as well as the "waterproofness" described above. For
example, the water vapor of perspiration generated from the human body of a
wearer
is released through the waterproof laminated product to the outside. This
makes it
possible to prevent stuffiness while wearing. The "moisture permeability" as
used
herein refers to the property of allowing the transmission of water vapor. The
desired "moisture permeability" may preferably be not smaller than 50 g/m2.h,
more
preferably not smaller than 100 g/m2.h, based on the rate of moisture
permeability as
measured by, for example, the JIS L 1099 B-2 method.
[0061]
Examples of the waterproof moisture-permeable sheet may include films
formed of hydrophilic resins such as polyurethane resins, polyester resins,
silicone
resins, and polyvinyl alcohol resins; and porous films formed of hydrophobic
resins
(which may hereinafter be referred to simply as "hydrophobic porous films")
such as
polyester resins, polyolefin resins, e.g., polyethylene and polypropylene,
fluorine-
containing resins, and polyurethane resins subjected to water-repellent
treatment.
The "hydrophobic resins" as used herein refers to resins in which the contact
angle
of a water droplet placed on the surface of a smooth and flat plate formed of
each of
the resins is not smaller than 60 degrees (as measured at a temperature of 25
C),
more preferably not smaller than 80 degrees.
[0062]
In the hydrophobic porous sheet, its porous structure having pores
(continuous pores) in the inside thereof maintains the moisture permeability,
while
the hydrophobic resin forming the base material of the sheet prevents water
from
infiltrating the pores. Thus, the hydrophobic porous sheet exhibits
waterproofness as
23
CA 02737687 2011-03-17
the entire sheet. Among these, the waterproof moisture-permeable sheet may
preferably be a porous film formed of a fluorine-containing resin, more
preferably a
porous PTFE film.
[0063]
The shape, the size, and the number of attached units of the waterproof
sound-permeable means included in the waterproof sound-permeable hood of the
present invention are not particularly limited, but may appropriately be
modified or
changed depending on the waterproof sound-permeable membrane, the protective
layer, and the holding member to be used. For example, when a porous PTFE film
is
used as the waterproof sound-permeable membrane and the holding member to be
used has a cylindrical swaging part having an inner diameter of 9 mm, the
number of
attached units of the waterproof sound-permeable means may preferably be at
least
one and not greater than six.
[0064]
Another Embodiment
Referring to FIGS. 6 and 7, the following will describe another embodiment
of the waterproof sound-permeable hood of the present invention, where a
holding
member is not used. FIG. 6 is a perspective view showing the waterproof sound-
permeable hood in an embodiment in which a waterproof sound-permeable means
does not have a holding member. FIG. 7 is a side view of the waterproof sound-
permeable hood shown in FIG. 6.
[0065]
In the waterproof sound-permeable hood of the present embodiment, the
waterproof sound-permeable means 10 does not have a holding member, but is
formed only of the waterproof sound-permeable membrane 11, or is formed of a
24
CA 02737687 2011-03-17
laminated product of the waterproof sound-permeable membrane 11 with a
protective
layer 12. The waterproof sound-permeable means 10 is attached to the
waterproof
hood 1 so as to close each sound-permeable opening 2a provided in the
waterproof
material 2 forming the waterproof hood 1. The method of attaching the
waterproof
sound-permeable means 10 is not particularly limited. For example, the
waterproof
sound-permeable membrane 11 and the protective layer 12 may be cut into a
predetermined size and then may be sewn onto, or fusion-bonded to, the
waterproof
material 2 so as to close each sound-permeable opening 2a.
[0066]
The waterproof sound-permeable membrane or the laminated waterproof
sound-permeable membrane may be sewn onto the waterproof material using a
sewing machine or any other means. As the material of the sewing thread to be
used
for the sewing, the following materials may be used alone, or any mixture of
the
following materials may also be used: cotton; silk; linen; polynosic;
polyamide
resins; polyester resins; vinylon resins; and polyurethane resins. Polyamide
resins or
polyester resins may preferably be used in view of strength and heat
resistance. The
thickness of the sewing thread may appropriately be adjusted depending on the
thickness of the laminated product to be sewn and the required strength of the
final
product. The method of sewing is not particularly limited, so long as the
sewing is
carried out using one or more threads. As the form of the stitch, lock stitch,
single
chain stitch, double chain stitch, or any other stitch may preferably be used,
and
there can be mentioned sewing in a linear, curved, zigzag, or any other
manner.
[0067]
In addition, examples of the method of melt bonding the waterproof sound-
permeable membrane or the laminated product of the waterproof sound-permeable
CA 02737687 2011-03-17
membrane with the support may include an indirectly melt bonding method using
a
sheet formed of a hot-melt resin (which may hereinafter be referred to simply
as a
"hot-melt sheet"). As the hot-melt sheet, there can be mentioned "Gore-Seam
(registered trademark) Sheet Adhesive" available from Japan Gore-Tex Inc. In
addition, as the hot-melt resin of the hot-melt sheet, there can be used the
same as the
one to be used for a hot-melt resin layer of a seam-sealing tape described
later. As
the conditions for melt bonding using the hot-melt sheet, there can be
employed the
same as those for compression-bonding a seam-sealing tape.
[0068]
In addition, as shown in FIG. 6, the portion where the waterproof sound-
permeable membrane or the laminated waterproof sound-permeable membrane has
been sewn or fusion-bonded may preferably be subjected to seam-sealing
treatment.
The seam-sealing treatment further improves the waterproofness and the
strength of
the waterproof sound-permeable hood obtained.
[0069]
The method of seam-sealing treatment is not particularly limited, so long as
the waterproofness can be ensured for the seam portion or the fusion-bonded
portion.
For example, when the waterproof sound-permeable membrane or the laminated
waterproof sound-permeable membrane is sewn onto the waterproof material,
there
may be preferred a method of closing the needle hole portions with a resin,
because
higher waterproofness can be attained. As the method of closing the needle
hole
portions with a resin, there can be mentioned a method of applying a resin to
the
seam portion and a method of adhering or melt bonding a tape-shaped resin
(seam-
sealing tape). The method using a seam-sealing tape may be preferred, because
the
seam-sealed portion has a higher waterproof durability. In addition, when the
26
CA 02737687 2011-03-17
waterproof sound-permeable membrane or the laminated waterproof sound-
permeable membrane is fusion-bonded to the waterproof material, the strength
of the
waterproof sound-permeable hood obtained is decreased. Therefore, the fusion-
bonded portion is subjected to seam-sealing treatment using a seam-sealing
tape or
any other means, thereby improving the strength of the waterproof sound-
permeable
hood obtained.
[0070]
As the seam-sealing tape to be used for the seam-sealing treatment of the
seam portion or the fusion-bonded portion in the waterproof sound-permeable
hood
of the present invention, there can appropriately be used a tape in which a
low
melting-point adhesive resin is laminated on the back face (the seam side) of
a base
material tape formed of a high melting-point resin, preferably a seam-sealing
tape in
which a hot-melt resin layer is provided on the back face of a base material
tape.
The front face (the side exposed to the outside) of the base material tape may
be
subjected to lamination processing with a knit, a mesh, or any other material.
As the
seam-sealing tape, there can appropriately be used, for example, seam-sealing
tapes
such as "T-2000" and "FU-700" available from San Chemicals, Ltd., and seam-
sealing tapes such as "MF-12T2" and "MF-IOF" available from Nisshinbo
Industries, Inc., each using a polyurethane resin film as the base material
tape and
using a polyurethane hot-melt resin as the adhesive resin; and "GORE-SEAM
(registered trademark) Tape" available from Japan Gore-Tex Inc., using a
porous
PTFE film as the base material tape and using a polyurethane hot-melt resin as
the
adhesive resin.
[0071]
As the hot-melt resin of the seam-sealing tape, the following various resins
27
CA 02737687 2011-03-17
may be used alone, or two or more kinds of the following various resins may
also be
used as a mixture: polyethylene resins or copolymer resins thereof; polyamide
resins;
polyester resins; butyral resins; polyvinyl acetate resins or copolymer resins
thereof;
cellulose derivative resins; polymethyl methacrylate resins; polyvinyl ether
resins;
polyurethane resins; polycarbonate resins; and polyvinyl chloride resins. When
the
hot-melt resin is used for a clothing product, polyurethane resins may be
preferred.
[0072]
The thickness of the hot-melt resin layer of the seam-sealing tape may
preferably be not smaller than 25 gm, more preferably not smaller than 50 gm,
but
may preferably be not greater than 400 m, more preferably not greater than
200 m.
When the thickness of the hot-melt resin layer is smaller than 25 m, the
amount of
resin is too small, which makes it difficult to completely cover the
irregularities of
threads in the needle holes, and there is fear that the waterproofness of the
seam
portion becomes insufficient. On the other hand, when the thickness of the hot-
melt
resin layer is greater than 400 m, there occurs the possibility that the
thermal
compression bonding of the tape may need a long time for sufficiently melting
the
hot-melt resin layer, thereby decreasing productivity, or may cause a thermal
damage
on the waterproof sound-permeable means, to which the tape is to be adhered.
In
addition, if the time for thermal compression bonding is shortened, the hot-
melt resin
layer does not sufficiently melt, resulting in that sufficient adhesive
strength and
sufficient waterproofness cannot be obtained.
[0073]
These seam-sealing tapes can be used for melt bonding processing with an
existing hot air sealer that applies hot air to the hot-melt resin layer side
of each tape,
and causes the compression bonding of the tape to an adherend with a pressure
roll in
28
CA 02737687 2011-03-17
the state where the resin is being melted. There can be used, for example,
"QHP-
805" available from Queen Light Electronic Industries Ltd., or "5000E"
available
from W. L. Gore & Associates, Inc. In addition, to achieve the melt bonding
processing of a short seam portion in an easier and simpler manner, the seam-
sealing
tape may be subjected to thermal compression bonding with a commercially
available heat press machine or iron. In this case, heat and pressure are
applied to
the seam-sealing tape layered on the seam portion. The conditions for thermal
compression bonding of the seam-sealing tape may appropriately be set
depending
on the softening point of the hot-melt resin to be used for the tape, the melt
bonding
speed, and any other factors.
Example
[0074]
The present invention will hereinafter be described in detail by reference to
Example; however, the present invention is not limited to the following
Example,
and various modifications, changes, and embodiments, which are made without
departing from the spirit of the present invention, are all included within
the scope of
the present invention.
[0075]
Evaluation Methods
1. Sound-Transmission Loss
The sound-transmission loss was measured using "Transmission Loss Tube
Kit (Type 4206-T)" and "PULSE sound and vibration analysis hardware (Type 3560-
C)" available from Bruel & Kjxr Sound & Vibration Measurement A/S. The
measurement conditions were as follows: a small tube (having an inner diameter
of
29
CA 02737687 2011-03-17
29 mm) was used as a transmission loss tube kit; and noise to be generated
from a
sound source was 120 db. The measurement was carried out in the state where
the
end opposite to the end, at which the sound source was disposed, of the
transmission
loss tube was closed, and also in the state where the opposite end was open.
The
sound-transmission loss was determined using analysis software "PULSE LabShop
Version 10.1Ø15" available from Bruel & Kjaer Sound & Vibration Measurement
A/S.
[0076]
2. Waterproofness
The waterproofness of waterproof sound-permeable hoods was evaluated by
visually checking the presence or absence of water leakage in the artificial
rain test
which was carried out using an artificial rain chamber under the conditions of
a
precipitation amount of not smaller than 50 mm/h and a period of 30 minutes.
[0077]
3. Durability Against Washing
The durability against washing of waterproof sound-permeable hoods was
evaluated by carrying out the above waterproof test after repeating the
washing
twenty times.
The step of washing the hood using a household fully-automatic washing
machine (available from Matsushita Electric Industrial Co., Ltd.; model number
"NA-F70PX I") and hanging the hood to dry at room temperature for 24 hours was
regarded as one cycle of the washing. Washing was carried out using 40 liters
of tap
water and 30 g of synthetic laundry detergent ("Attack (registered trademark)"
available from Kao Corporation) for 6 minutes, followed by rinsing two times
and
dewatering for 3 minutes.
CA 02737687 2011-03-17
[0078]
4. Sound Permeability
A bell alarm clock ("G07Y5G" available from DAILY) was placed 2 m away
from a subject wearing a rain jacket ("R03 Rain Jacket" available from Japan
Gore-
Tex Inc.), to which each of hoods obtained in the following Production
Examples is
attached, or to which no hood is attached, such that the bell alarm clock was
placed
on one side of the subject, or in other words, placed so as to be directed to
one ear of
the subject. When the bell alarm clock was sounded in the state where the hood
was
worn, and also in the state where no hood was worn, noise near the ear of the
subject
was measured with a sound level meter (Sound Level Meter "NL-20" available
from
Rion Co., Ltd.). When the hood was worn, the detection section of the sound
level
meter was provided within the hood.
[0079]
Laminated Waterproof Sound-Permeable Membrane
A mesh laminate as a laminated waterproof sound-permeable membrane was
prepared as follows: a porous PTFE film (available from Japan Gore-Tex Inc.,
and
having a thickness of 8.5 m, a mass per unit area of 2.3 g/m2, an air
permeability
(Gurley number) of 0.032 sec., and a porosity of 87.4%) was used as a
waterproof
sound-permeable membrane; a polypropylene mesh ("Conwed (registered trademark)
net (having a thickness of 0.48 m and a mass per unit area of 100 g/m2)"
available
from Nisseki Plasto Co., Ltd.) was used as a protective layer; and the
protective layer
was firmly attached to the waterproof sound-permeable membrane by thermal
lamination (at 170 C for 5 seconds). The sound-transmission loss was measured
for
the obtained mesh laminate. The result is shown in Table 1.
[0080]
31
CA 02737687 2011-03-17
Waterproof Material Having Waterproof Sound-Permeable Means
A waterproof material having waterproof sound-permeable means was
prepared by attaching the mesh laminate as the laminated waterproof sound-
permeable membrane obtained as described above to a waterproof material ("EB
FPL70WDH/6366-WR" available from Japan Gore-Tex Inc.). For the attachment of
the mesh laminate, a net eyelet (available from Morito Co., Ltd.; the
cylindrical
swaging part thereof has an inner diameter of 9 mm and the protective layer
thereof
is a wire fabric) was used as a holding member, and the number of attached
mesh
laminate was one. The gap between the holding portion of the mesh eyelet and
the
mesh laminate was sealed with a silicone resin.
[0081]
The structure of the waterproof sound-permeable means according to the
present Example will be specifically described by reference to FIG 5. That is,
the
fabric corresponds to the waterproof material 2; the porous PTFE film forming
the
mesh laminate corresponds to the waterproof sound-permeable membrane 11; and
the polypropylene mesh corresponds to the protective layer 12a. In addition,
the
mesh eyelet corresponds to the holding member 20 and the female ring 24; the
wire
fabric included in the mesh eyelet corresponds to the protective layer 12b;
and the
silicone resin corresponds to the sealing member 23.
[0082]
The sound-transmission loss was measured for the obtained waterproof
material having the waterproof sound-permeable means. Further, as a
comparative
example, the sound-transmission loss of the waterproof material and the sound-
transmission loss of the waterproof material including an opening having an
inner
diameter of 10 mm were also measured. The results are shown in Table 1.
32
CA 02737687 2011-03-17
[0083]
[Table 1]
Sound-transmission loss (db)
Mesh laminate 2.76
Waterproof material having waterproof
sound-permeable means 8'75
Waterproof material 10.5
Waterproof material (having opening) 1.70
[0084]
Waterproof Hoods
Production Example 1
A waterproof hood was prepared by sewing a waterproof laminate ("EB
FPL70WDH/6366-WR" available from Japan Gore-Tex Inc.) as a waterproof
material. The seam was sealed using a seam-sealing tape ("GORE-SEAM
(registered trademark) Tape" available from Japan Gore-Tex Inc.). A waterproof
sound-permeable hood was prepared by attaching a waterproof sound-permeable
means to each of the portions of the obtained waterproof hood, which portions
respectively face to the right and left ears of a wearer. The waterproof sound-
permeable means had the same structure as used in the waterproof material
having
the waterproof sound-permeable means, and the number of attached means was one
for each of the portions facing to the right and left ears of the wearer.
[0085]
When a waterproof test and a durability-against-washing test were carried out
for the obtained waterproof sound-permeable hood, water leakage was not
observed
in either test. In addition, a sound permeability test was carried out for the
waterproof sound-permeable hood. The result is shown in Table 2.
[0086]
33
CA 02737687 2011-03-17
Production Example 2
A waterproof hood was prepared using the same waterproof laminated
product and seem-sealing tape as those which were used in Production Example
1. A
sound permeability test was carried out for the obtained waterproof hood. The
result
is shown in Table 2.
[0087]
Production Example 3
A waterproof hood was prepared using the same waterproof laminated
product and seem-sealing tape as those which were used in Production Example
1.
The waterproof hood obtained was provided with an opening having an inner
diameter of 25 mm each on the portions respectively facing to the right and
left ears
of a wearer to prepare a sound-permeable hood. A sound permeability test was
carried out for the obtained sound-permeable hood. The result is shown in
Table 2.
[0088]
[Table 2]
Sound noise measured value (db)
Waterproof sound-permeable hood 67.5
Waterproof hood 66.7
Sound-permeable hood 68.8
No hood 72.7
Industrial Applicability
[0089]
The present invention is useful for waterproof hoods having excellent
waterproofness and excellent sound permeability.
Explanation of Symbols
34
CA 02737687 2011-03-17
[0090]
1: Waterproof hood; 2: waterproof material; 2a: opening for sound-
permeation; 3: seam-sealing tape; 10: waterproof sound-permeable means; 11:
waterproof sound-permeable membrane; 12: protective layer; 20: holding member;
21: cylindrical swaging part; 22: holing part; 23: sealing member; and 24:
female
ring.
