阅读说明：本技术 防水构件和电子设备 (Waterproof member and electronic device ) 是由 福岛玉青 菅谷阳辅 平井文太 阿部悠一 于 2018-12-28 设计创作，主要内容包括：本公开的防水构件具有容许声音和/或气体通过并且防止水侵入的防水膜、和具有厚度方向的透气性的支承层,所述防水构件具有：接合区域,在该接合区域中,所述防水膜与所述支承层接合；以及非接合区域,在该非接合区域中,所述防水膜与所述支承层处于彼此分开的状态,在从与所述防水膜的主面垂直的方向看时,所述非接合区域由所述接合区域包围,所述非接合区域中的所述支承层的厚度小于100μm。本公开的防水构件例如是具有防水透声膜和该膜的支承层的防水透声构件,且是改善了透声特性的构件。(The waterproof member of the present disclosure has a waterproof membrane that allows sound and/or gas to pass through and prevents water intrusion, and a support layer having air permeability in a thickness direction, the waterproof member having: a joining region in which the waterproof film is joined to the support layer; and a non-joined region in which the waterproof film and the support layer are in a state of being separated from each other, the non-joined region being surrounded by the joined region when viewed from a direction perpendicular to a main surface of the waterproof film, the support layer in the non-joined region having a thickness of less than 100 μm. The waterproof member of the present disclosure is, for example, a waterproof sound-transmitting member having a waterproof sound-transmitting membrane and a supporting layer of the membrane, and is a member having improved sound-transmitting characteristics.)

1. A waterproof member having a waterproof membrane that allows sound and/or gas to pass therethrough and prevents water intrusion, and a support layer having air permeability in a thickness direction,

the waterproof member has:

a joining region in which the waterproof film is joined to the support layer; and

a non-joint region in which the waterproof film and the support layer are in a state of being separated from each other,

the non-bonding region is surrounded by the bonding region when viewed from a direction perpendicular to a main surface of the waterproof film,

the thickness of the support layer in the non-engagement region is less than 100 μm.

2. The waterproof member according to claim 1,

the supporting layer is a non-woven fabric, a grid body, a mesh body or a through hole sheet.

3. The waterproof member according to claim 1,

the supporting layer is a mesh body.

4. The waterproof member according to any one of claims 1 to 3,

the area of the non-joined region as viewed from the perpendicular direction was 12mm²The following.

5. The waterproof member according to any one of claims 1 to 4,

the ratio of the area of the non-joined region to the sum of the area of the joined region and the area of the non-joined region when viewed in the vertical direction is 20% or less.

6. The waterproof member according to any one of claims 1 to 5, wherein,

the waterproof membrane comprises a Polytetrafluoroethylene (PTFE) membrane.

7. The waterproof member according to any one of claims 1 to 6, wherein,

the air permeability of the waterproof film in the thickness direction is represented by Gurley air permeability and is 20 seconds/100 mL or more.

8. The waterproof member according to any one of claims 1 to 7,

in the joining region, the waterproof film and the support layer are joined with a double-sided adhesive tape.

9. The waterproof member according to any one of claims 1 to 8,

the waterproof film and the support layer in the non-joined region are separated by a distance of 200 μm or less.

10. The waterproof member according to any one of claims 1 to 9,

a fixing portion having a shape surrounding the non-joined region when viewed in a direction perpendicular to a main surface of the waterproof membrane is formed on a surface of the waterproof membrane opposite to the joining surface joined to the supporting layer and/or a surface of the supporting layer opposite to the joining surface joined to the waterproof membrane.

11. An electronic device, wherein,

the electronic device has:

a housing having an opening; and

the waterproof member according to any one of claims 1 to 10, which is attached to the housing so as to close the opening,

the waterproof member is attached to the case in such a manner that one side of the waterproof membrane of the waterproof member faces the outside of the case and one side of the supporting layer of the waterproof member faces the inside of the case.

12. The electronic device of claim 11,

a voice converting part for converting an electric signal and a voice is accommodated in the housing,

the opening is located between the voice converting part and the outside of the housing.

Technical Field

The invention relates to a waterproof member and an electronic apparatus.

Background

Wearable devices such as mobile phones, smart watches, and electronic devices such as cameras have a voice function. A voice converter (transducer) such as a speaker or a microphone is housed inside a casing of an electronic device having a voice function. An opening (external sound transmission port) for introducing sound from the outside to the voice converter and/or for leading out sound from the voice converter to the outside is provided in the casing of the electronic apparatus. Water must be prevented from entering the interior of the housing. Therefore, a waterproof sound-transmitting membrane capable of allowing sound to pass therethrough and preventing water from intruding is attached to the external sound-transmitting port.

A waterproof sound-transmitting member having a waterproof sound-transmitting membrane and a supporting layer supporting the membrane is well known. By having the supporting layer, for example, it is possible to prevent the breakage of the waterproof sound-transmitting membrane caused by the water pressure applied to the waterproof sound-transmitting member when the electronic apparatus is dropped into water. Patent document 1 discloses a waterproof sound-transmitting member in which a porous polytetrafluoroethylene (hereinafter referred to as "PTFE") membrane and a porous support layer are selectively bonded to each other at their peripheral edges.

Disclosure of Invention

Problems to be solved by the invention

According to the waterproof sound-transmitting member of patent document 1, the waterproof sound-transmitting membrane and the supporting layer are independently freely vibrated in the non-bonded region on the inner side where they are not bonded to each other, and thus, high sound-transmitting characteristics can be obtained although the waterproof sound-transmitting member has the supporting layer. However, in order to cope with miniaturization of electronic equipment, the size of the waterproof sound-transmitting member tends to be limited. Therefore, further improvement of the sound transmission characteristics is required for the waterproof sound-transmitting member.

In addition, the waterproof film may be attached to an opening provided in a housing of the electronic device, and the opening does not require sound transmission. The opening is, for example, a ventilation opening for ensuring ventilation inside and outside the casing. In this case, the waterproof film functions only as a waterproof breathable film that allows gas to pass therethrough and prevents water from entering. A waterproof and breathable member having a waterproof and breathable film and a support layer supporting the film is also used.

The object of the present invention is to improve the characteristics of a waterproof member which is a waterproof sound-transmitting member and/or a waterproof air-permeable member.

Means for solving the problems

Conventionally, improvement of the sound transmission characteristics of a waterproof sound-transmitting member having a waterproof sound-transmitting membrane and a supporting layer has been achieved by improving the sound transmission characteristics of the waterproof sound-transmitting membrane. However, there is a limit to a method of improving the sound transmission characteristics only by improving the waterproof sound transmission membrane. In addition, the improvement of the sound-transmitting property of the waterproof sound-transmitting membrane may cause a decrease in the waterproofness of the membrane. As a result of the investigation by the present inventors, it has been found that in a waterproof sound-transmitting member in which a waterproof sound-transmitting membrane is selectively bonded to a supporting layer, the improvement of the supporting layer can improve sound-transmitting characteristics. The improvement of the supporting layer can also improve the characteristics of the waterproof and breathable member.

That is, the present invention provides a waterproof member,

the waterproof member has a waterproof membrane that allows sound and/or gas to pass through and prevents water intrusion, and a support layer having air permeability in the thickness direction, wherein,

the waterproof member has:

a joining region in which the waterproof film is joined to the support layer; and

a non-joint region in which the waterproof film and the support layer are in a state of being separated from each other,

the non-bonding region is surrounded by the bonding region when viewed from a direction perpendicular to a main surface of the waterproof film,

the thickness of the support layer in the non-engagement region is less than 100 μm.

In another aspect, the present invention provides an electronic device,

the electronic device has:

a housing having an opening; and

the waterproof member of the present invention is mounted to the housing so as to close the opening,

the member is attached to the housing such that one side of the waterproof membrane of the member faces the outside of the housing and one side of the support layer of the member faces the inside of the housing.

ADVANTAGEOUS EFFECTS OF INVENTION

According to the present invention, not only the sound transmission characteristics of a waterproof sound-transmitting member having a waterproof sound-transmitting membrane and a supporting layer for the membrane can be improved, but also the characteristics of a waterproof member having a waterproof membrane and a supporting layer for the membrane can be improved.

Drawings

Fig. 1A is a sectional view schematically showing one example of a waterproof member (waterproof sound-transmitting member) of the present invention.

Fig. 1B is a plan view of the waterproof sound-transmitting member shown in fig. 1A as viewed from the side of the waterproof sound-transmitting membrane.

Fig. 2 is a sectional view schematically showing another example of the waterproof member (waterproof sound-transmitting member) of the present invention.

Fig. 3 is a sectional view schematically showing still another example of the waterproof member (waterproof sound-transmitting member) of the present invention.

Fig. 4 is a sectional view schematically showing still another example of the waterproof member (waterproof sound-transmitting member) of the present invention.

Fig. 5 is a cross-sectional view schematically showing an example of the waterproof member (waterproof sound-transmitting member) of the present invention, which is different from the above.

Fig. 6 is a cross-sectional view schematically showing an example of the waterproof member (waterproof sound-transmitting member) of the present invention, which is different from the above.

Fig. 7 is a front view showing an example of an electronic device (smartphone) in which a waterproof member (waterproof sound-transmitting member) of the present invention is attached to an opening (external sound-transmitting port) of a housing.

Fig. 8 is a diagram for explaining a method of evaluating the sound transmission characteristics of the waterproof sound-transmitting member, which is performed in the example.

Detailed Description

Embodiments of the present invention are described below with reference to the drawings. The present invention is not limited to the following embodiments.

Fig. 1A and 1B show an example of a waterproof sound-transmitting member of the present invention. Fig. 1B shows the waterproof sound-transmitting member 1 as viewed from the side of the waterproof sound-transmitting membrane 2. The section a-a shown in fig. 1B is shown in fig. 1A.

The waterproof sound-transmitting member 1 has: a joining region 5 in which the waterproof sound-transmitting membrane 2 is joined to the support layer 3; and a non-bonded region 4, the non-bonded region 4 being surrounded by a bonded region 5 when viewed from a direction perpendicular to the main surface of the waterproof sound-transmitting membrane 2 (fig. 1B). The joining region 5 includes regions of the peripheral edge portions of the waterproof sound-transmitting membrane 2 and the support layer 3. The waterproof sound-transmitting membrane 2 and the support layer 3 are joined by a joint 6.

As shown in fig. 1A, in the non-joining region 4, the support layer 3 is separated from the waterproof sound-transmitting membrane 2. The support layer 3 has air permeability in the thickness direction. The thickness of the support layer 3 in the non-joining zone 4 is less than 100 μm. That is, in the non-joined region 4, the support layer 3 having air permeability in the thickness direction and having a thickness of less than 100 μm is disposed separately from the waterproof sound-transmitting membrane 2.

The waterproof sound-transmitting member 1 can be attached to a housing of an electronic apparatus having a voice function. The waterproof sound-transmitting member 1 can be attached to the housing so as to cover the external sound-transmitting port and to direct one side surface of the waterproof sound-transmitting membrane 2 to the outside (external space). With the waterproof sound-transmitting member 1 having the waterproof sound-transmitting membrane 2, sound can be transmitted between the voice converter provided in the electronic apparatus and the outside, and water can be prevented from entering the inside of the electronic apparatus through the external sound-transmitting port. When water pressure is applied to the external sound-transmitting port of the electronic apparatus to which the waterproof sound-transmitting member 1 is attached, the waterproof sound-transmitting membrane 2 deforms in the direction of the support layer 3 (the direction from the outside into the case) in the non-joined region 4. However, in the waterproof sound-transmitting member 1, the deformation of the waterproof sound-transmitting membrane 2 is limited to a certain range by the contact of the deformed waterproof sound-transmitting membrane 2 with the support layer 3, and the breakage of the waterproof sound-transmitting membrane 2 can be prevented. Thus, by having the support layer 3, the waterproof sound-transmitting member 1 can have higher waterproofness than the waterproof sound-transmitting membrane 2 itself has (for example, extreme water pressure resistance).

Deformation (hereinafter referred to as "permanent deformation") remaining in the waterproof sound-transmitting membrane 2 after the escape of the water pressure deteriorates the sound-transmitting characteristics of the waterproof sound-transmitting member 1. The support layer 3 can alleviate the permanent deformation of the waterproof sound-transmitting membrane 2 by restricting the deformation of the waterproof sound-transmitting membrane 2.

The shapes of the waterproof sound-transmitting member 1 and the non-joined region 4 are not limited. In the example shown in fig. 1A and 1B, the waterproof sound-transmitting member 1 is rectangular and the non-bonded region 4 is circular when viewed from a direction perpendicular to the main surface of the waterproof sound-transmitting membrane 2. The shapes of the waterproof sound-transmitting member 1 and the non-joint region 4 are independent of each other, and are, for example, a circle (including substantially a circle), an ellipse (including substantially an ellipse), and a polygon including a rectangle and a square. The corners of the polygon may also be rounded. The waterproof sound-transmitting member 1 can be attached between an external sound-transmitting port and an internal sound-transmitting port so that, for example, the sound-transmitting port (internal sound-transmitting port) of the speech converter is covered with the surface on the support layer 3 side and the sound-transmitting port (external sound-transmitting port) provided in the housing is covered with the surface on the waterproof sound-transmitting membrane 2 side.

The shape of the joining region 5 is not limited as long as it surrounds the non-joining region 4. The joining region 5 is typically a region including the peripheral edge portion of the waterproof sound-transmitting membrane 2 and/or the support layer 3. In the example shown in fig. 1A and 1B, the region other than the joining region 5 where the waterproof sound-transmitting membrane 2 is joined to the support layer 3 is the non-joining region 4. In the example shown in fig. 1A and 1B, in the non-joint region 4, the waterproof sound-transmitting membrane 2 is exposed to one face of the waterproof sound-transmitting member 1. In addition, in the non-joining region 4, the support layer 3 is exposed to the other face of the waterproof sound-transmitting member 1.

The waterproof sound-transmitting member 1 can have high sound-transmitting characteristics, although having the non-joint region 4 with a small area. The area of the non-bonded region 4 when viewed from the direction perpendicular to the main surface of the waterproof sound-transmitting membrane 2 is, for example, 12mm²The following. The area of the non-joint region 4 may be 10mm²Below, 8.0mm²Below, 5.0mm²Below, 3.2mm²2.0mm below²Below, even 1.8mm²The following. The lower limit of the area of the non-joined region 4 is not limited, and is, for example, 0.02mm²The above. The waterproof sound-transmitting member 1 is suitable for use in a small-sized electronic device having a voice function. An example of a small electronic device is a wearable device such as a smart watch.

The ratio of the area of the non-joined region 4 to the total of the area of the joined region 5 and the area of the non-joined region 4 when viewed from the direction perpendicular to the main surface of the waterproof sound-transmitting membrane 2 in the waterproof sound-transmitting member 1 is not limited, and is, for example, 1 to 90%. The upper limit of the proportion may be 50% or less, 20% or less, 15% or less, or even 10% or less. The smaller the above ratio, i.e., the larger the ratio of the joining region 5 to the waterproof sound-transmitting member 1, the more firmly the waterproof sound-transmitting membrane 2 and the support layer 3 can be joined. Therefore, the smaller the above ratio, the more the degree of deformation and permanent deformation of the waterproof sound-transmitting membrane 2 due to the water pressure can be further reduced, the more the waterproofness of the waterproof sound-transmitting member 1 can be improved, or the more reliably the decrease in the sound-transmitting property of the waterproof sound-transmitting member 1 due to the water pressure can be suppressed.

The shape of the waterproof sound-transmitting membrane 2 and the shape of the support layer 3 may be the same or different when viewed from a direction perpendicular to the principal surface of the waterproof sound-transmitting membrane 2. In the example shown in fig. 1A and 1B, the shape of the waterproof sound-transmitting membrane 2 and the shape of the support layer 3 are the same as each other, and are also the same as the shape of the waterproof sound-transmitting member 1.

The thickness of the waterproof sound-transmitting member 1 is, for example, 500 μm or less. The thickness of the waterproof sound-transmitting member 1 may be 300 μm or less, 250 μm or less, or even 200 μm or less. The lower limit of the thickness of the waterproof sound-transmitting member 1 is not limited, and is, for example, 60 μm or more. The waterproof sound-transmitting member 1 is suitable for use in a small electronic device in which the volume inside the housing is limited. In addition, in an electronic device having a voice function, when the distance from the external sound-transmitting port to the voice converter is increased, the voice converted by the voice converter tends to be deteriorated. The deterioration of sound is particularly serious when the speech converter is a sound receiving unit such as a microphone, or when the area of the external sound transmission port and/or the internal sound transmission port is small. When the thickness of the waterproof sound-transmitting member 1 is within the above range, the distance from the external sound-transmitting port to the internal sound-transmitting port is not excessively large even if the waterproof sound-transmitting member 1 is disposed. Therefore, deterioration of the sound converted by the voice converter can be suppressed.

The separation distance between the waterproof sound-transmitting membrane 2 and the support layer 3 in the non-joined region 4 is, for example, 200 μm or less. The separation distance may also be 150 μm or less, 130 μm or less, 100 μm or less, less than 100 μm, or even 80 μm or less. The lower limit of the separation distance is not limited, and may be, for example, 5 μm or more, or 10 μm or more, 20 μm or more, or even 30 μm or more. In the case where the separation distance of the waterproof sound-transmitting membrane 2 from the support layer 3 in the non-joined region 4 is within these ranges, deformation and permanent deformation of the waterproof sound-transmitting membrane 2 due to water pressure can be more reliably suppressed. In addition, the thickness of the waterproof sound-transmitting member 1 can be made more reliably within the above range.

The thickness of the support layer 3 in the non-joining zone 4 is less than 100 μm. The thickness of the support layer 3 may be 99 μm or less, 80 μm or less, 70 μm or less, 60 μm or less, 55 μm or less, 50 μm or less, 45 μm or less, or even 40 μm or less. The lower limit of the thickness is not limited, and is, for example, 2 μm or more. The support layer 3 is not limited to the non-engagement areas 4 and can have the above-mentioned thickness. The support layer 3 may have the above thickness as a whole. In addition, the support layer 3 having a thickness of less than 100 μm also contributes to a reduction in the thickness of the waterproof sound-transmitting member 1.

The support layer 3 is not limited as long as it has air permeability in the thickness direction. The air permeability of the support layer 3 in the thickness direction is generally higher than the air permeability of the waterproof sound-transmitting membrane 2 in the thickness direction. In addition, the strength of the support layer 3 is generally higher than that of the waterproof sound-transmitting membrane 2.

The material constituting the support layer 3 is not limited, and examples thereof include metals such as aluminum and stainless steel, polyolefins (polyethylene, polypropylene, and the like), polyesters (polyethylene terephthalate (PET), and the like), polyamides (various aliphatic polyamides including nylon, aromatic polyamides, and the like), resins such as polyimide, and composite materials thereof.

The form of the support layer 3 is not limited, and examples thereof include nonwoven fabric, woven fabric, mesh, and perforated sheet. The mesh body and the mesh body have a lattice structure composed of a space between skeletons (generally referred to as "eyes") and skeletons. The skeleton of the lattice structure is made of fibers such as filaments, wires, and tubes. The filaments may also be monofilament or multifilament. In the present specification, the mesh body is used as a term having the following meaning: a structure in which fibers are woven with fibers and the fibers are three-dimensionally crossed at intersections (intersections of a lattice structure) between the fibers, and a lattice body is used as a term as follows: the crossing fibers are integrated with the fibers at the crossing points and are not woven.

The through-hole sheet is a sheet in which a plurality of through-holes (perforations) penetrating the sheet in the thickness direction are provided in an original sheet having a non-porous matrix structure, for example, a non-porous sheet. The through-hole sheet may be a sheet having no air-permeable path in the thickness direction other than the plurality of through-holes. The through hole may be a straight hole extending linearly in the thickness direction of the sheet. The mesh body and the eyes of the mesh body are generally polygonal such as a quadrangle when viewed from a direction perpendicular to the main surface of the through hole piece, whereas the shape of the opening of the through hole is generally circular or elliptical. The shape of the cross section of the through hole may be constant from one main surface to the other main surface of the sheet, or may vary from one main surface to the other main surface of the sheet. The through holes may be formed such that their openings are regularly arranged on the main surface of the sheet when viewed in a direction perpendicular to the main surface, or may be formed such that their openings are randomly located on the main surface. The via sheet may be a metal sheet or a resin sheet. The through hole can be formed by, for example, laser processing or opening processing by ion beam irradiation and subsequent chemical etching of the original sheet. By laser processing, through holes having openings regularly arranged on the main surface of the sheet when viewed in a direction perpendicular to the main surface can be more reliably formed. As the through-hole sheet, for example, the sheet disclosed in japanese patent laid-open No. 2012-20279 can be used. However, the sheet may be subjected to or may not be subjected to the liquid-repellent treatment.

The material and form of the support layer 3 can be arbitrarily combined.

The support layer 3 is preferably a mesh or grid, and particularly preferably a mesh. The mesh body and the grid body are suitable for maintaining the strength under the thickness of less than 100 mu m. Therefore, in the waterproof sound-transmitting member 1 having the support layer 3 as the mesh body or the mesh body, deformation and permanent deformation of the waterproof sound-transmitting membrane 2 caused by water pressure can be more reliably suppressed. In addition, when the support layer 3 is a mesh body or a mesh body, the rigidity and handling property of the waterproof sound-transmitting member 1 can be improved. Wherein the mesh body is adapted to improve the sound transmission characteristics of the waterproof sound-transmitting member 1.

When the skeleton is made of a resin such as PET, the weight per unit area of the support layer 3 as a mesh body is, for example, 25 to 70g/m². The lower limit of the weight per unit area may be 30g/m²Above 35g/m²Above, even 38g/m²The above. The upper limit of the weight per unit area may be 60g/m²55g/m below²Below, even 45g/m²The following. When the skeleton is made of metal such as stainless steel, the weight per unit area of the support layer 3 as the mesh body is, for example, 30 to 140g/m². The lower limit of the weight per unit area may be 35g/m²Above, 50g/m²Above 60g/m²Above, even 70g/m²The above. The upper limit of the weight per unit area may be 130g/m²120g/m or less²Below, even 115g/m²The following.

The waterproof sound-transmitting membrane 2 is not limited as long as it allows sound to pass therethrough and prevents water from entering. Various well-known waterproof sound-transmitting membranes can be applied to the waterproof sound-transmitting membrane 2. The water-repellent sound-transmitting membrane 2 may be subjected to lyophobic treatment or oleophobic treatment.

The waterproof sound-transmitting membrane 2 may be made of polyester such as PET, polycarbonate, polyethylene, polyimide, PTFE, or other resins. As a material of the waterproof sound-transmitting membrane 2, PTFE is suitable. The membrane made of PTFE (PTFE membrane) has a good balance between quality and strength.

The PTFE membrane may be a porous membrane (PTFE porous membrane) formed by extending a paste extrudate or a cast membrane containing PTFE particles. The PTFE membrane may also be fired.

In the case where the electronic apparatus mounted with the waterproof sound-transmitting member 1 is assumed to be placed under higher water pressure, the PTFE membrane is preferably a PTFE microporous membrane or a PTFE nonporous membrane. The PTFE microporous membrane and the PTFE nonporous membrane can have high water pressure resistance and a small degree of deformation due to water pressure.

In the present specification, the PTFE microporous membrane refers to a membrane in which: the air permeability in the thickness direction is a membrane having an air permeability (Gurley air permeability) measured by an air permeability measurement method B (Gurley shape method) specified in japanese industrial standards (hereinafter, JIS) L1096, and is 20 seconds/100 mL or more and 1 ten thousand seconds/100 mL or less. The lower limit of the Gurley air permeability of the PTFE microporous membrane may be more than 30 seconds/100 mL, or 40 seconds/100 mL or more, 50 seconds/100 mL or more, or even 70 seconds/100 mL or more. The upper limit of the Gurley air permeability of the PTFE microporous membrane may be 5000 seconds/100 mL or less, 1000 seconds/100 mL or less, or even 300 seconds/100 mL or less. In the present specification, a PTFE non-porous membrane refers to a membrane that: the air permeability in the thickness direction was set to the above Gurley air permeability, and was a film exceeding 1 ten thousand seconds/100 mL.

In addition, when the size of the waterproof sound-transmitting membrane 2 does not satisfy the size of the test piece (about 50mm × 50mm) in the Gurley shape method described above, the Gurley air permeability can be evaluated by using a measuring jig. An example of the measuring jig is a circular plate made of polycarbonate having a thickness of 2mm and a diameter of 47mm, which is provided with a through hole (circular cross section having a diameter of 1mm or 2mm) at the center. The measurement of Gurley air permeability using the measurement jig can be performed as follows.

The method for measuring Gurley air permeability includes the steps of passing air only through an opening and an effective test portion (a portion overlapping the opening when viewed in a direction perpendicular to a main surface of a fixed waterproof sound-transmitting membrane) of the waterproof sound-transmitting membrane to be evaluated, and fixing the waterproof sound-transmitting membrane by using a double-sided adhesive tape in which an air-permeable port having a shape conforming to the shape of the opening is punched at a center portion, wherein the double-sided adhesive tape is disposed between the measurement jig and the waterproof sound-transmitting membrane such that a peripheral portion of the air-permeable port conforms to a peripheral portion of the opening, and measuring the air permeability of the waterproof sound-transmitting membrane by using a waterproof sound-transmitting membrane measuring apparatus having a fixed waterproof sound-transmitting membrane disposed downstream of the fixed surface of the waterproof sound-transmitting membrane in the air flow direction during measurement, wherein the time t1 for passing 100mL of air through the waterproof sound-transmitting membrane is measured by using a waterproof sound-transmitting membrane (1 mm) area measuring apparatus [ 1mm (1 mm) of the waterproof sound-transmitting membrane²])/642[mm²]And converting the measured time t1 into air permeability measurement B method (Gurley method) of JIS L1096 at every 642[ mm ]²]The value t of the effective test area can be set as the Gurley air permeability of the waterproof sound-transmitting membrane. In the case of using the above circular plate as a measuring jig, the area of the effective test portion of the waterproof sound-transmitting membrane is the area of the cross section of the through hole.

When the temperature of the case is lowered by using the case in water or mounting electronic equipment, dew condensation may occur inside the case. The amount of water vapor accumulated in the casing can be reduced to prevent dew condensation. When the waterproof sound-transmitting membrane 2 is a PTFE non-porous membrane, it is possible to prevent water vapor from entering the interior of the case through the waterproof sound-transmitting membrane 2. Therefore, by selecting a PTFE non-porous membrane as the waterproof sound-transmitting membrane 2, the amount of water vapor accumulated in the casing can be reduced, and dew condensation can be prevented from occurring in the casing.

On the other hand, even if no water vapor enters the interior of the case through the waterproof sound-transmitting membrane 2, it may be unavoidable that water vapor remains in the interior of the case. For example, the case may be made of a resin having moisture absorption properties such as polybutylene terephthalate (PBT), acrylonitrile-butadiene-styrene (ABS), polymethyl methacrylate (PMMA), polypropylene (PP), or Polycarbonate (PC). In the case made of a resin having a moisture-absorbing property, the external water vapor absorbed in the case itself tends to be released into the case by heat from the heat source in the case and directly stagnated. In this case, in order to prevent dew condensation from occurring inside the casing, it is preferable to select the waterproof sound-transmitting membrane 2 capable of releasing water vapor accumulated inside the casing to the outside. An example of a waterproof sound-transmitting membrane 2 that can be selected is a PTFE microporous membrane. When the waterproof sound-transmitting membrane 2 is a PTFE microporous membrane, high waterproof property can be achieved, and the retained water vapor can be discharged to the outside by appropriate air permeability of the membrane 2, and dew condensation can be prevented from occurring inside the case.

The average pore diameter of the waterproof sound-transmitting membrane 2 as a PTFE microporous membrane is, for example, 0.01 to 1 μm. The porosity of the waterproof sound-transmitting membrane 2 as a PTFE microporous membrane is, for example, 5 to 50%. The average pore diameter of the PTFE membrane can be measured based on ASTM (American society for testing and materials) F316-86. The porosity of the PTFE film can be calculated by substituting the mass, thickness, area (area of the main surface), and true density of the film into the following expressions. Further, the true density of PTFE was 2.18g/cm³。

Porosity (%) {1- (mass [ g) }]/(thickness [ cm)]× area [ cm ]²]× true density [2.18g/cm³]))}×100

The thickness of the waterproof sound-transmitting membrane 2 is, for example, 1 to 50 μm. The thickness of the waterproof sound-transmitting membrane 2 may be 3 to 30 μm or 5 to 20 μm. When the thickness of the waterproof sound-transmitting membrane 2 is within these ranges, the waterproof property and the sound-transmitting property of the waterproof sound-transmitting membrane 2 can be improved in a well-balanced manner.

The surface density of the waterproof sound-transmitting membrane 2 is, for example, 1 to 30g/m². The surface density of the waterproof sound-transmitting membrane 2 may be 1 to 25g/m². The surface density can be calculated by dividing the mass of the waterproof sound-transmitting membrane 2 by the area (the area of the main surface).

The waterproofness of the waterproof sound-transmitting membrane 2 can be evaluated by water pressure resistance (ultimate water pressure resistance). The water pressure resistance of the waterproof sound-transmitting membrane 2 is, for example, 80kPa or more. The water pressure resistance of the waterproof sound-transmitting membrane 2 may be 100kPa or more, 300kPa or more, 500kPa or more, 600kPa or more, 700kPa or more, 750kPa or more, 800kPa or more, 900kPa or more, or even 1000kPa or more. The upper limit of the water pressure resistance is not limited, and is, for example, 2000kPa or less. The water pressure resistance of the waterproof sound-transmitting membrane 2 can be measured by the water resistance test a method (low water pressure method) or B method (high water pressure method) by JISL1092 using a measuring jig as follows.

An example of the measuring jig is a circular plate made of stainless steel having a diameter of 47mm provided with a through hole (having a circular cross section) having a diameter of 1mm at the center. The disk has a thickness that is not deformed by the water pressure applied when measuring the water pressure resistance. The water pressure resistance measurement using the measuring jig can be performed as follows.

A waterproof sound-transmitting membrane as an evaluation object is fixed to one surface of the jig so as to cover the opening of the through hole of the measurement jig. The fixing is performed in such a manner that water is prevented from leaking from the fixed portion of the membrane in the measurement of the water pressure resistance. In the fixing of the waterproof sound-transmitting membrane, a double-sided pressure-sensitive adhesive tape can be used in which a water passage port having a shape conforming to the shape of the opening is punched in the center portion. The double-sided adhesive tape may be disposed between the measuring jig and the waterproof sound-transmitting membrane so that the peripheral portion of the water passage opening coincides with the peripheral portion of the opening. Next, a measuring jig to which the waterproof sound-transmitting membrane is fixed is set in a test apparatus so that a surface of the waterproof sound-transmitting membrane opposite to the fixed surface becomes a water pressure applying surface at the time of measurement, and water pressure resistance is measured according to a water resistance test a method (low water pressure method) or a B method (high water pressure method) of JIS L1092. The water pressure resistance is measured based on the water pressure at which water flows out from one place of the membrane surface of the waterproof sound-transmitting membrane. The measured water pressure resistance can be set to the water pressure resistance of the waterproof sound-transmitting membrane. The following devices can be used as the test device: the test piece mounting structure has the same structure as the water resistance test apparatus exemplified in JIS L1092, and can be provided with the measurement jig.

Penetration of the waterproof sound-transmitting membrane 2The acoustic characteristics can be evaluated by the insertion loss at 1kHz (insertion loss with respect to sound of frequency 1 kHz). The area of the sound-transmitting area of the membrane is 1.8mm²In this case, the insertion loss of the waterproof sound-transmitting membrane 2 at 1kHz is, for example, 17dB or less, and may be 13dB or less, 10dB or less, 8dB or less, 7dB or less, or even 6dB or less.

The sound transmission characteristics of the waterproof sound-transmitting membrane 2 can also be evaluated by the insertion loss at 200Hz (insertion loss with respect to sound at a frequency of 200 Hz). The area of the sound-transmitting area of the membrane is 1.8mm²In this case, the insertion loss of the waterproof sound-transmitting membrane 2 at 200Hz is, for example, 13dB or less, or 11dB or less, 10dB or less, or even 8dB or less.

The degree of decrease in the sound-transmitting characteristics of the waterproof sound-transmitting membrane 2 due to the water pressure can be evaluated by the rate of decrease in the sound-transmitting characteristics (rate of change in insertion loss) obtained from the insertion loss of the waterproof sound-transmitting membrane 2 before and after the water pressure holding test. The water pressure holding test is a test in which a certain water pressure is applied to the waterproof sound-transmitting membrane for a certain time (water pressure application time). The water pressure holding test can be performed using the above-described measuring jig and water resistance test apparatus for measuring the water pressure resistance of the waterproof sound-transmitting membrane. More specifically, as in the case of measuring the water pressure resistance, the measuring jig to which the waterproof sound-transmitting membrane is fixed may be installed in the testing apparatus such that the surface of the waterproof sound-transmitting membrane opposite to the fixed surface is a water pressure applying surface, and the water pressure may be applied to the waterproof sound-transmitting membrane for a certain period of time. In this case, if water leaks from one position of the membrane surface of the waterproof sound-transmitting membrane, it is determined that "water leakage" is present. The water pressure applied to the waterproof sound-transmitting membrane in the test is not limited, and is, for example, 50kPa to 1000 kPa. The water pressure application time is, for example, 10 minutes to 30 minutes. The sound transmission characteristic degradation rate can be obtained by the following equation. L1 in the following formula represents the insertion loss of the waterproof sound-transmitting membrane before the test (for example, the insertion loss at 1 kHz), and L2 represents the insertion loss of the waterproof sound-transmitting membrane after the test (for example, the insertion loss at 1 kHz).

Sound transmission characteristic degradation rate (%) (L2-L1)/L1 × 100

The sound transmission characteristic degradation rate (calculated based on the insertion loss at 1 kHz) of the waterproof sound-transmitting membrane 2 determined from the insertion loss before and after the water pressure holding test (water pressure of 500kPa, water pressure application time of 10 minutes) is, for example, 50% or less, or 40% or less, 30% or less, or even 25% or less.

In the example shown in fig. 1A and 1B, the waterproof sound-transmitting membrane 2 is a single-layer membrane. The waterproof sound-transmitting membrane 2 may be a laminate of two or more membranes. The waterproof sound-transmitting membrane 2 may be a laminate of two or more PTFE membranes.

The waterproof sound-transmitting membrane 2 may also be a colored membrane. The waterproof sound-transmitting membrane 2 may also be colored, for example, gray or black. The gray or black waterproof sound-transmitting membrane 2 can be formed, for example, by mixing a gray or black coloring agent into the material constituting the membrane. The black colorant is, for example, carbon black. In addition, it can be expressed by "achromatic brightness NV" defined in JIS Z8721 that colors within a range of 1 to 4 are defined as "black", and colors within a range of 5 to 8 are defined as "gray".

The structure of the joint portion 6 is not limited as long as the joint region 5 and the non-joint region 4 can be formed. The bonding portion 6 is, for example, an adhesive layer or an adhesive layer. The joint portion 6 as the adhesive layer or the adhesive layer can be formed by applying a known adhesive or bonding agent to the surface of the waterproof sound-transmitting membrane 2, for example. The joint portion 6 may be formed of a double-sided adhesive tape. That is, the waterproof sound-transmitting membrane 2 may be joined to the support layer 3 in the joining region 5 by a double-sided adhesive tape. When the joint portion 6 is formed of a double-sided adhesive tape, the joint between the waterproof sound-transmitting membrane 2 and the support layer 3 is more reliable, and the waterproofness of the waterproof sound-transmitting member 1 can be further improved. In addition, the control of the separation distance of the waterproof sound-transmitting membrane 2 from the support layer 3 in the non-joined region 4 becomes easier.

A known double-sided adhesive tape can be used as the double-sided adhesive tape constituting the joint portion 6. The substrate of the double-sided adhesive tape is, for example, a film of resin, a nonwoven fabric or a foam. The resin that can be used for the base material is not limited, and examples thereof include polyester (PET, etc.), polyolefin (polyethylene, etc.), and polyimide. As the pressure-sensitive adhesive layer of the double-sided pressure-sensitive adhesive tape, various pressure-sensitive adhesives such as acrylic pressure-sensitive adhesives and silicone pressure-sensitive adhesives can be used. An acrylic adhesive is preferably used for the adhesive layer in order to improve the bonding force between the waterproof sound-transmitting membrane 2 and the support layer 3. The double-sided adhesive tape may also be a thermal adhesive tape.

The thickness of the joint portion 6 is, for example, 200 μm or less. The thickness of the joint portion 6 may be 150 μm or less, 130 μm or less, 100 μm or less, less than 100 μm, or even 80 μm or less. The lower limit of the thickness of the bonding portion 6 is not limited, and may be, for example, 5 μm or more, or 10 μm or more, 20 μm or more, or even 30 μm or more. When the thickness of the joint portion 6 is within these ranges, the separation distance between the waterproof sound-transmitting membrane 2 and the support layer 3 in the non-joined region 4 can be controlled within the above-described preferable range, and deformation and permanent deformation of the waterproof sound-transmitting membrane 2 due to water pressure can be more reliably suppressed.

The waterproof sound-transmitting member 1 can be disposed between a case of an electronic device and a voice converter housed in the case. The waterproof sound-transmitting member 1 is usually fixed to the inner wall surface of the housing so as to cover the external sound-transmitting port. The waterproof sound-transmitting member 1 can be fixed to the casing of the voice converter or the surface of the substrate having the voice converter so as to cover the internal sound-transmitting port. The positional relationship between the external sound-transmitting port and the internal sound-transmitting port in the fixed state and the non-joint region 4 of the waterproof sound-transmitting member 1 is not limited as long as the voice can be transmitted between the external sound-transmitting port and the voice converter. The outer sound-transmitting port and the inner sound-transmitting port in the fixed state may overlap with the non-joined region 4 when viewed from a direction perpendicular to the main surface of the waterproof sound-transmitting membrane 2.

The fixing method of the waterproof sound-transmitting member 1 with respect to the housing and the voice converter is not limited. The waterproof sound-transmitting member 1 can be fixed to the housing and/or the voice converter by various welding such as heat welding, ultrasonic welding, laser welding, or adhesion using an adhesive, or the like. The waterproof sound-transmitting member 1 can also be fixed by a fixing portion composed of an adhesive layer, or a double-sided adhesive tape. In the case where the fixing portion is formed of a double-sided adhesive tape, the waterproof sound-transmitting member 1 can be more reliably fixed to the housing and the voice converter. The double-sided adhesive tape constituting the fixing portion can be the one described in the description of the joining portion 6. The waterproof sound-transmitting member 1 fixed to both the housing and the voice converter may be fixed to the housing by the same method as that for fixing to the voice converter, or may be fixed to the housing by a different method.

Fig. 2 shows an example of the waterproof sound-transmitting member of the present invention further having a fixing portion 7A. In the waterproof sound-transmitting member 1 shown in fig. 2, the fixing portion 7A is disposed on the surface of the waterproof sound-transmitting membrane 2 opposite to the bonding surface bonded to the support layer 3. The fixing portion 7A includes a peripheral edge region of the waterproof sound-transmitting membrane 2 when viewed from a direction perpendicular to the main surface of the waterproof sound-transmitting membrane 2. The fixing portion 7A has the same shape as the joining region 5 when viewed from the above-described perpendicular direction. The fixing portion 7A has an opening 8 having a shape corresponding to the non-joined region 4 when viewed in the vertical direction. The sound propagates mainly through the opening 8 of the fixing portion 7A. The opening 8 is a sound-transmitting region of the waterproof sound-transmitting membrane 2 and the waterproof sound-transmitting member 1. The opening 8 is aligned with the non-bonded region 4 when viewed in the vertical direction. The waterproof sound-transmitting member 1 shown in fig. 2 can be fixed to the housing by the fixing portion 7A. The shape of the opening 8 of the fixing portion 7A may be the same as the shape of the external sound transmission port of the housing. In this case, the waterproof sound-transmitting member 1 can be fixed to the housing so that the peripheral portion of the opening 8 and the peripheral portion of the external sound-transmitting port coincide with each other when viewed in the vertical direction.

Fig. 3 shows another example of the waterproof sound-transmitting member of the present invention further having a fixing portion 7A. The waterproof sound-transmitting member 1 shown in fig. 3 is the same as the waterproof sound-transmitting member 1 shown in fig. 2 except for the shape of the fixing portion 7A. The fixing portion 7A of the waterproof sound-transmitting member 1 shown in fig. 3 has an opening 8 that is larger than the non-joined region 4 when viewed in the vertical direction and overlaps with the non-joined region 4 (more specifically, includes the non-joined region 4). In the waterproof sound-transmitting member 1 shown in fig. 3, the shape of the opening 8 of the fixing portion 7A may be the same as the shape of the external sound-transmitting port of the housing. In the waterproof sound-transmitting member 1 shown in fig. 3, the area of the non-joined region 4 can be made smaller than the area of the external sound-transmitting port. Therefore, the waterproof performance of the electronic apparatus to which the waterproof sound-transmitting member 1 is fixed can be further improved.

Fig. 4 shows an example of the waterproof sound-transmitting member of the present invention further having the fixing portion 7B. In the waterproof sound-transmitting member 1 shown in fig. 4, the fixing portion 7B is disposed on the surface of the support layer 3 opposite to the bonding surface bonded to the waterproof sound-transmitting membrane 2. The fixing portion 7B may have the same shape as the fixing portion 7A shown in fig. 2 or 3 when viewed from the direction perpendicular to the principal surface of the waterproof sound-transmitting membrane 2. The waterproof sound-transmitting member 1 shown in fig. 4 can be fixed to the voice converter by the fixing portion 7B.

Fig. 5 shows an example of the waterproof sound-transmitting member of the present invention further having fixing portions 7A, 7B. In the waterproof sound-transmitting member 1 shown in fig. 5, the fixing portion 7A is disposed on the surface of the waterproof sound-transmitting membrane 2 opposite to the bonding surface bonded to the support layer 3. The fixing portion 7B is disposed on the surface of the support layer 3 opposite to the bonding surface to be bonded to the waterproof sound-transmitting membrane 2. The fixing portions 7A and 7B may have the same shape as the fixing portions 7A shown in fig. 2 or 3 when viewed from the direction perpendicular to the principal surface of the waterproof sound-transmitting membrane 2. The shape of the fixing portion 7A may be the same as or different from that of the fixing portion 7B. The waterproof sound-transmitting member 1 shown in fig. 5 can be fixed to the housing by the fixing portion 7A and can be fixed to the voice converter by the fixing portion 7B.

The shape of the fixing portions 7A and 7B is not limited to the above examples. However, from the viewpoint that sound is mainly propagated through the openings 8 of the fixing portions 7A and 7B, the fixing portions 7A and 7B preferably have a shape that is accommodated in the joint region 5 when viewed in a direction perpendicular to the main surface of the waterproof sound-transmitting membrane 2. The thickness of the waterproof sound-transmitting member 1 having the fixing portion 7A and/or the fixing portion 7B is defined including the thickness of the fixing portion.

The waterproof sound-transmitting member of the present invention may have any layer and/or member other than those described above as long as the effects of the present invention can be obtained.

The waterproofness of the waterproof sound-transmitting member 1 can be evaluated by water pressure resistance (limit water pressure resistance). The water pressure resistance of the waterproof sound-transmitting member 1 can be measured according to the above-described method of measuring the water pressure resistance of the waterproof sound-transmitting membrane 2. Wherein the water pressure at the time of measurement is applied to the waterproof sound-transmitting member 1 from one side of the waterproof sound-transmitting membrane 2. The waterproof sound-transmitting member 1 has a higher water pressure resistance than the waterproof sound-transmitting membrane 2.

The waterproofness of the waterproof sound-transmitting member 1 can also be evaluated by a water pressure holding test. The water pressure holding test can be performed in the same manner as the water pressure holding test for the waterproof sound-transmitting membrane. Wherein the water pressure at the time of the test is applied to the waterproof sound-transmitting member 1 from one side of the waterproof sound-transmitting membrane 2. The waterproof sound-transmitting member 1 can be a member that: even if a water pressure holding test in which the water pressure is 60kPa and the water pressure application time is 10 minutes is performed, water leakage does not occur in the waterproof sound-transmitting membrane 2. The waterproof sound-transmitting member 1 can be a member that: even if a water pressure holding test in which the water pressure is 500kPa and the water pressure application time is 10 minutes is performed, water leakage does not occur in the waterproof sound-transmitting membrane 2. The waterproof sound-transmitting member 1 can be a member that: even if a water pressure holding test in which the water pressure is 700kPa and the water pressure application time is 30 minutes is performed, water leakage does not occur in the waterproof sound-transmitting membrane 2. The waterproof sound-transmitting member 1 can be a member that: even if the water pressure holding test is repeatedly performed 30 times with the water pressure of 700kPa and the water pressure application time of 30 minutes with the interval between the tests set to 1 minute, the waterproof sound-transmitting membrane 2 does not leak water.

The sound transmission characteristics of the waterproof sound-transmitting member 1 can be evaluated by the insertion loss at 1kHz (insertion loss with respect to sound of a frequency of 1 kHz). The insertion loss at 1kHz of the waterproof sound-transmitting member 1 was 1.8mm in the area of the non-joined region 4²For example, 17dB or less, 13dB or less, 10dB or less, 9dB or less, 8dB or less, 7dB or less, or even 6.5dB or less may be used.

The sound transmission characteristics of the waterproof sound-transmitting member 1 can also be evaluated by the insertion loss at 200Hz (insertion loss with respect to sound at a frequency of 200 Hz). The insertion loss at 200Hz of the waterproof sound-transmitting member 1 was 1.8mm in the area of the non-joined region 4²For example, the value is 14dB or less, and may be 12dB or less, 11dB or less, 10dB or less, or even 9dB or less.

The sound transmission characteristics of the waterproof sound-transmitting member 1 can also be evaluated by the increase in the insertion loss of the waterproof sound-transmitting member 1 relative to the insertion loss of the waterproof sound-transmitting membrane 2 (the insertion loss of the waterproof sound-transmitting membrane 2 itself measured without providing the support layer 3) (relative to the increase of the waterproof sound-transmitting membrane alone). The increase amount can be represented by the formula: [ increase in insertion loss]Insertion loss of waterproof sound-transmitting member 1]- [ insertion loss of Water-proof Sound-transmitting Membrane 2]And (4) obtaining. The area of the non-joint region 4 is 1.8mm²In this case, the increase in insertion loss of the waterproof sound-transmitting member 1 at 1kHz is, for example, 5dB or less, and may be 4dB or less, 2dB or less, 1.5dB or less, or even 1dB or less. The area of the non-joint region 4 is 1.8mm²In the case, the amount of increase in insertion loss of the waterproof sound-transmitting member 1 at 200Hz is, for example, 10dB or less, and may be 6dB or less, 5dB or less, 4dB or less, 2dB or less, 1.5dB or less, or even 1dB or less. In particular, the amount of increase can be reduced in the case where the support layer 3 is a mesh body.

In the waterproof sound-transmitting member 1, the deterioration of sound-transmitting characteristics due to the water pressure can be suppressed. After a water pressure holding test in which the water pressure was 500kPa and the water pressure application time was 10 minutes, the area at the non-joining region 4 was 1.8mm²In this case, the waterproof sound-transmitting member 1 also exhibits an insertion loss at 1kHz of, for example, 11dB or less. The insertion loss may be below 10dB, below 9dB, below 7dB, even below 6.5 dB.

The sound transmission characteristic degradation rate (calculated from the insertion loss at 1 kHz) of the waterproof sound-transmitting member 1 determined from the insertion loss before and after the water pressure holding test (water pressure of 500kPa, water pressure application time of 10 minutes) may be, for example, less than 6.6%, 6.0% or less, 5.5% or less, 5.0% or less, 4.0% or less, 3.0% or less, 2.0% or less, 1.5% or less, or even 1.0% or less. The sound transmission characteristic degradation rate of the waterproof sound-transmitting member can be evaluated by the above-described method for evaluating the sound transmission characteristic degradation rate of the waterproof sound-transmitting membrane, except that the object for measuring the insertion loss is changed from the waterproof sound-transmitting membrane to the waterproof sound-transmitting member.

The waterproof sound-transmitting member 1 can be supplied in a form of being disposed on a sheet-like base film or a form of being disposed on a strip-like base film and wound into a roll or reel (reel), for example. In the arrangement of the waterproof sound-transmitting member 1 with respect to the base film, the fixing portion 7A or the fixing portion 7B can be utilized. A release layer may be formed on the surface of the base film on which the waterproof sound-transmitting member 1 is disposed, and the release layer facilitates the release of the waterproof sound-transmitting member 1 from the base film. The base film can be, for example, a polymer film, paper, a metal film, and a composite film thereof. Fig. 6 shows an example of a state in which the waterproof sound-transmitting member 1 is disposed on the base film. In the example shown in fig. 6, a waterproof sound-transmitting member 1 is disposed on a base film 11 via a fixing portion 7A. In addition, in the waterproof sound-transmitting member 1 shown in fig. 6, the fixing portion 7B is provided with a separation film 12 for protecting the fixing portion 7B and the non-joined region 4. When the waterproof sound-transmitting member 1 is used, the separator 12 is peeled off.

The purpose of the waterproof sound-transmitting member 1 is not limited. The waterproof sound-transmitting member 1 can be used for applications requiring both sound-transmitting properties and waterproof properties, and can be used for, for example, a waterproof sound-transmitting structure, an article having a waterproof sound-transmitting structure, and the like. The waterproof sound-transmitting member 1 is typically used for an electronic apparatus having a voice function.

Fig. 7 shows an example of an electronic device using the waterproof sound-transmitting member 1. The electronic device shown in fig. 7 is a smartphone 20. A voice converter for converting an electric signal and voice is disposed inside the case 22 of the smartphone 20. The speech converter is for example a loudspeaker, a microphone. The housing 22 is provided with an opening 23 and an opening 24 as external sound transmission ports.

In the smartphone 20, the 1 st waterproof sound-transmitting member 1 is fixed to an inner wall surface of the case 22 so as to cover the opening 23. The 2 nd waterproof sound-transmitting member 1 is fixed to the inner wall surface of the housing 22 so as to cover the opening 24. With regard to the two waterproof sound-transmitting members 1, the face on the waterproof sound-transmitting membrane 2 side faces the outside via the opening 23 or the opening 24. Further, the non-joint region 4 of each waterproof sound-transmitting member 1 overlaps with the opening 23 or the opening 24 when viewed from the direction perpendicular to the principal surface of the waterproof sound-transmitting membrane 2.

The 1 st waterproof sound-transmitting member 1 and the 2 nd waterproof sound-transmitting member 1 are fixed to a voice converter (not shown) housed in the casing. With regard to the two waterproof sound-transmitting members 1, the face on the support layer 3 side is in contact with the voice converter. Further, the non-joint region 4 of each waterproof sound-transmitting member 1 overlaps the inner sound-transmitting port of the voice converter to which each waterproof sound-transmitting member 1 is fixed, when viewed from the direction perpendicular to the principal surface of the waterproof sound-transmitting membrane 2.

The voice converter (voice conversion unit) is, for example, a speaker or a microphone. The speech transducer may also be a microphone.

The electronic device capable of using the waterproof sound-transmitting member 1 is not limited to the smartphone 20. The electronic devices are wearable devices such as smartwatches and bracelets, various cameras including sports cameras and anti-theft cameras, communication devices such as cell phones and smartphones, Virtual Reality (VR) devices, Augmented Reality (AR) devices, sensor devices, and the like.

The waterproof sound-transmitting member 1 can be used as a waterproof and air-permeable member even when the waterproof sound-transmitting membrane 2 has air permeability in the thickness direction. At this time, the waterproof sound-transmitting membrane 2 functions as a waterproof and air-permeable membrane that allows permeation of gas and prevents intrusion of water. The waterproof breathable member can be attached to the case so as to cover an opening (breathable opening) connecting the inside and outside of the case and to allow one side surface of the waterproof breathable film to face the outside (external space). The waterproof and breathable member having the waterproof and breathable film allows the inside and the outside of the case to be breathable through the opening in the electronic device, and prevents water from entering the inside of the case through the opening. The electronic device may have a voice conversion unit or may not have a voice conversion unit. When water pressure is applied to the opening of the electronic device to which the waterproof and breathable member is attached, the waterproof and breathable film deforms in the direction toward the support layer 3 (direction from the outside toward the inside of the case) in the non-joined region 4. However, in the waterproof and breathable member, the deformation of the waterproof and breathable film is limited to a certain range by the contact between the deformed waterproof and breathable film and the support layer 3, and the breakage of the waterproof and breathable film can be prevented. Thus, by having the support layer 3, the waterproof breathable member can have higher water repellency than the waterproof breathable film itself has (e.g., the limit water pressure resistance).

The permanent deformation remaining in the waterproof breathable film after the escape of the water pressure deteriorates the air permeability of the waterproof breathable member, for example, causes unevenness in air permeability or causes variation from the air permeability designed as the waterproof breathable member. The support layer 3 can alleviate the permanent deformation by restricting the deformation of the waterproof breathable film. In the case where the electronic device is a sensor device such as a pressure sensor, for example, variations in air permeability and variations in air permeability characteristics from design may adversely affect the performance of the device.

Further, the thickness of the support layer 3 in the non-joined region 4 is less than 100 μm, so that the responsiveness of air permeation as a waterproof and breathable member can be improved. The improvement in the responsiveness to air permeation is particularly advantageous in the case where the electronic device is a sensor device such as a pressure sensor.

In the waterproof member of the present invention as the waterproof and breathable member, the waterproof membrane can have the same structure as the waterproof and acoustically transparent member 1 as long as it has breathability in the thickness direction. The waterproof and breathable film of the waterproof and breathable member can be selected from the waterproof and breathable films 2 described above, which have breathability in the thickness direction. In addition, the waterproof member of the present invention as the waterproof and breathable member can have the same characteristics as the waterproof and acoustically transparent member 1.

In the waterproof member of the present invention as the waterproof and breathable member, variation in the breathable characteristics due to water pressure can be suppressed. The change rate of the air permeability characteristics before and after the water pressure holding test (water pressure of 500kPa, water pressure application time of 10 minutes) is, for example, 5% or less, or 4% or less, 3% or less, 2% or less, or even 1% or less. Regarding the rate of change in the air permeability characteristic of the waterproof and air-permeable member, the air permeability of the waterproof and air-permeable member before the water pressure holding test (air permeability in the direction of passing through the waterproof and air-permeable film and the support layer 3) can be represented by AP1, and the air permeability of the waterproof and air-permeable member after the water pressure holding test can be represented by AP2, and the following formula: i (| (AP2-AP1) |/AP1 × 100 (%). In addition, the air permeability of the waterproof and breathable member can be adjusted based on JIS P8117: 2009 was determined as the air impermeability (unit: sec/100 mL). The recommended dimensions of the test piece in the joker test method are 50mm × 50mm, but even when the dimensions of the waterproof and breathable member to be evaluated do not satisfy the recommended dimensions, the air impermeability of the test piece can be evaluated by the joker test method by using the measuring jig.

The measuring jig has a shape and a size that can be arranged in an air permeability measuring section of the joker test machine, and is made of a material and a thickness that are not deformed by a pressure difference applied to the test piece when measuring the air impermeability. An example of the measuring jig is a circular plate made of polycarbonate having a thickness of 2mm and a diameter of 47 mm. A through hole having an opening smaller in size than a waterproof and breathable member to be evaluated is provided in advance in the center in the plane of the measuring jig. The cross section of the through hole is typically circular, and is set to a diameter such that the opening of the through hole is completely covered by the waterproof and breathable member of the evaluation target. As the diameter of the through hole, for example, 1mm or 2mm can be adopted. Next, a waterproof and breathable member to be evaluated is fixed to one surface of the measuring jig so as to cover the opening. The fixation is performed in the following manner: in the measurement of the air impermeability, air passes only in the non-joined region 4, and the fixed portion does not obstruct the passage of air in the non-joined region 4. Either the waterproof breathable film faces the side of the measuring jig or the supporting layer 3 faces the side of the measuring jig. In the fixing of the waterproof and breathable member, a double-sided adhesive tape can be used in which a breathable opening having a shape conforming to the shape of the opening is punched in the center. The double-sided adhesive tape may be disposed between the measurement jig and the waterproof air-permeable member so that the peripheral portion of the air-permeable opening coincides with the peripheral portion of the opening. Next, a measurement jig to which the waterproof and breathable member is fixed is provided in the air permeability measurement unit of the jones test machine so that the fixing surface of the member is on the downstream side of the air flow at the time of measurement, a test by the jones test machine method is performed, and an air impermeability indication value t2 indicated by the test machine is recorded. Then, using the formula t_KT2 × (area of non-junction region 4 cm)²])/6.452[cm²]Converting the recorded air impermeability indication value t2 into each 6.452 cm specified by the Wanyan type testing machine method²]Value t of effective test area_KCan convert the obtained converted value t_KThe air impermeability of the waterproof and breathable member was measured by the royal jelly test method.

Examples of electronic devices that can use the waterproof member of the present invention as the waterproof and breathable member are a pressure sensor, a flow rate sensor, and a gas concentration sensor (O)₂Sensors, etc.). However, the electronic device is not limited to the above example.

As described above, the waterproof member of the present invention may be a waterproof sound-transmitting member,

the waterproof sound-transmitting member has a waterproof sound-transmitting membrane that allows sound to pass therethrough and prevents water from invading, and a support layer having air permeability in the thickness direction, wherein,

the member has:

a joining region in which the waterproof sound-transmitting membrane is joined to the support layer; and

a non-joint region in which the waterproof sound-transmitting membrane and the support layer are in a state of being separated from each other,

the non-joined region is surrounded by the joined region when viewed from a direction perpendicular to a main surface of the waterproof sound-transmitting membrane,

the thickness of the support layer in the non-engagement region is less than 100 μm.

The waterproof member of the present invention may be a waterproof and breathable member,

the waterproof and breathable member has a waterproof and breathable film that allows gas to pass therethrough and prevents water from invading, and a support layer having breathability in the thickness direction,

the member has:

a joining region in which the waterproof breathable film is joined to the support layer; and

a non-joined region in which the waterproof breathable film and the support layer are in a state of being separated from each other,

the non-joined region is surrounded by the joined region when viewed from a direction perpendicular to the main surface of the waterproof breathable film,

the thickness of the support layer in the non-engagement region is less than 100 μm.