JPH05320255A - Oil repellent waterproof breathable filter products - Google Patents

Abstract

(57) [Summary] [Purpose] In order to prevent the waterproof ventilation filter from deteriorating the waterproof ventilation performance due to the adhesion of oil such as detergent or surfactant, the waterproof ventilation filter is provided with oil repellency without impairing the waterproof ventilation. Provide electronic equipment, precision equipment, and storage cases. [Structure] Amorphous fluoropolymer is used as the breathable substrate, especially 60 to 90 mol% of perfluoro-2,2-dimethyl-
An oil-repellent waterproof breathable filter made of a material containing an amorphous polymer composed of 1,3-carbonyl, 40 to 10 mol% of tetrafluoroethylene, and optionally a small amount of another monomer is used for electronic equipment and precision equipment. It should be provided in a storage case.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a product such as an electronic device or a precision device using an oil repellent waterproof ventilation filter.

[0002]

2. Description of the Related Art When waterproofing communication equipment such as mobile phones, cordless telephones, intercoms, and electronic equipment such as cameras, telephones are used for sound propagation, cameras are used for zooming and focusing, and temperature is further increased. In order to alleviate the change in the internal pressure due to the change, a waterproof vent hole is required. Also, when a precision device such as a pressure sensor or pressure switch requires a vent hole, it must be waterproofed to maintain the performance of the precision device, and the battery vents the gas generated inside and prevents water from entering. There is a need. In addition, it is necessary to ventilate the inside of the storage case, but it is often difficult for water to pass through.

In such a case, conventionally, a porous polytetrafluoroethylene resin sheet, a non-woven fabric, a mesh or the like coated with polytetrafluoroethylene resin has been used as a waterproof gas permeable membrane (filter). It was

[0004]

Although the conventional waterproof ventilation filter fulfills the purpose of waterproofness and breathability, it can be used for liquids containing surfactants such as detergents and shampoos used in general living environments. If the filter portion is touched even with a small amount of oil, there is a problem that the water resistance and air permeability of the filter are almost lost, and the originally required waterproof property and air permeability cannot be obtained.

Therefore, the present invention provides a waterproof ventilation filter that is oil-repellent and is durable against liquids and oils containing a surfactant.
It is an object to provide an electronic device, a precision device, a storage case, etc. using the same.

[0006]

In order to achieve the above object, the present invention provides an oil-repellent waterproof breathable filter made of a material in which an amorphous fluoropolymer is contained in a breathable substrate, and an electronic component incorporated therein. The electronic device case, the precision device case, or the storage case body or lid is provided.

By treating the breathable substrate with an amorphous fluoropolymer, it imparts improved oil repellency over conventional substrates (which had little oil repellency) without losing waterproofness. The amorphous fluoropolymer can retain the breathability of the breathable substrate. To maintain the breathability of the breathable substrate, the amorphous copolymer is coated so as not to completely block the vent holes.

The air-permeable base material that can be used is not particularly limited, and any gas-permeable material, especially air-permeable material, may be used, regardless of whether it is a natural material or a synthetic material. A net, a porous film, or a laminated product of these can be used. In addition, various additives (eg, UV stabilizers, colorants, plasticizers, etc.) are added to the base material to impart special properties or as processing aids, as long as they do not adversely affect the final product. You can Preferred breathable substrates include hydrophobic stretched polytetrafluoroethylene membranes and various laminated products thereof, and the Gurley number is preferably 1000 seconds or less, more preferably 600 seconds or less. The stretched porous polytetrafluoroethylene membrane as the breathable substrate preferably has a nominal pore diameter of 0.01 to 15 μm.

As the amorphous fluoropolymer, 60-
Amorphous copolymers consisting of 90% perfluoro-2,2-dimethyl-1,3-dioxole, 10-40 mol% tetrafluoroethylene and optionally small amounts of other monomers are preferred. Examples of this amorphous copolymer include "Teflon AF1600" (a product containing about 65 mol% of dioxole unit) manufactured by DuPont.
2400 "(a product containing about 85 mol% dioxole units)
and so on.

Such an amorphous fluoropolymer is used as a solvent, for example, perfluoro (2-butyltetrahydrofuran) [“Fluorinert FC-7” manufactured by Sumitomo 3M Limited].
5) ”, and the resulting solution is used as a treatment liquid for the air permeable base material. This solution must be diluted to leave the substrate breathable, typically 0.01-5.0.
A concentration of wt% is preferred.

The method of treating the air-permeable material with this solution is not particularly limited, and it can be treated by coating, impregnation, spraying or the like. The treated material is air dried or heat treated to evaporate the solvent. In the present invention, electronic devices refer to electronic components and general devices including electronic components, such as communication devices such as telephones, pagers, transceivers, intercoms, microphones, cameras, videos, radios, tape recorders, radio cassettes, televisions, etc. AV equipments (especially for portable use), electric razors, electric toothbrushes, watches, various timers, electronic notebooks, headphones, various motors, bath control units, bath foam generators, bath cleaning brushes, etc. Besides, it also includes electronic parts such as batteries. Further, the precision equipment is not particularly limited, and refers to general equipment requiring precision such as a pressure sensor, a temperature sensor, an oxygen sensor, a position measuring device, a fish finder, and various closed switches for automobiles. In addition to a general case for storing various things, the storage case,
It may be a case for storing a specific object, such as a battery case.

[0012]

Example Production sample 1 of oil-repellent waterproof breathable filter Polytetrafluoroethylene (PTF) as breathable substrate
E) Film (Gore-Tex film, nominal pore size 1.0 μm,
A film thickness of 0.3 mm) is used as a processing liquid, and "Teflon AF1600" (a dioxole unit is about 65 mol%) manufactured by DuPont.
Product of "Sumitomo 3M Company," Fluorinert FC-7
5 "was coated on a substrate using a solution of 1.0% by weight to obtain a filter sample 1 having the following characteristics.

Treated product Untreated product A) Gurley number [seconds] 1 1 35 B) WEP [kg / cm ² 1.1 1.2 C) Wetting property Ethanol 1h not wet after instant Engine oil 1h not wet after 30h Wet within 30 minutes D) Water resistance after engine oil adherence 0.5kg / cm ² 1min No water leakage Water leakage at 0kg / cm ² Sample 2 Polytetrafluoroethylene (PTF) as air-permeable base material
E) Film (Gore-Tex film, nominal pore size 1.0 μm,
Using a film thickness of 0.5 mm), "Teflon AF2400" manufactured by DuPont as a treatment liquid (about 85 mol% of dioxole unit)
Product of "Sumitomo 3M Company," Fluorinert FC-7
5 "was coated on a substrate using a solution of 1.0% by weight to obtain a filter sample 1 having the following characteristics.

Treated product Untreated product A) Gurley number [sec] 2000 70 B) WEP [kg / cm ² 2.0 1.5 C) Wettability Ethanol 1h not wet after instant Engine oil 1h not wet after 30h Wet within 30 minutes D) Oil resistance by engine oil 0.5kg / cm ² Water leakage at 0kg / cm ² at 1min No oil leakage Sample 3 Polytetrafluoroethylene (PTF) as air-permeable base material
E) Film (Gore-Tex film, nominal pore size 3.0 μm,
Film thickness 30 μm) and polypropylene delnet (thickness 0.
15mm non-woven fabric) and used as a treatment liquid for DuPont's "Teflon AF1600" (product containing about 65 mol% of dioxole unit) to Sumitomo 3M's "Fluorinert FC-75" at a concentration of 0.75% by weight. A substrate was coated with the dissolved solution to obtain a filter sample 1 having the following characteristics.

Treated product Untreated product A) Gurley number [seconds] 1.5 0.6 B) WEP [kg / cm ² 0.6 0.5 C) Wettability Washing "Bio beads" Do not get wet after 30 minutes Detergent "Mama Lemon" Not wet after 30 minutes Wet within 10 minutes D) Detergent contamination 0.1kg / cm ² 1min Water leakage resistance at 0kg / cm ² No water leakage In the above, the test methods were as follows.

A) Gurley number The resistance of the sample to the air flow was measured by an Oken type air permeability tester. The result is displayed in Gurley number. The Gurley number is 100 cm ³ of air per 1 inch ² (6.45 cm ² ) of 4.
It is the time (seconds) required to flow under the pressure of 88 inch (124 mm) H ₂ O. As a reference standard, ASTM D726-58, TAPPI-T4
There are 60, JIS P8117, and JIS L1096.

B) WEP (water intrusion pressure) test WEP is carried out by gradually applying water pressure from one side of the sample to the pressure kg / cm ² when water leakage is confirmed on the other side of the sample.
And The penetration of water was read by observing a change in the color of this paper by placing a pH paper on one side of the sample. As a reference standard, JIS K6328,
There is JIS L1092.

C) Wettability test 2-3 ml using a pipette or the like on the surface of the sample placed horizontally
The test liquid of (1) was gently dropped in the form of liquid droplets, and the state of wetting and the presence or absence of permeation under the naked eye were observed. Generally, a wet sample turns transparent. D) Water resistance after adhering engine oil After adhering engine oil to one entire surface of the sample and allowing it to stand for 1 hour, the adhering oil is removed and the water pressure is adjusted to 0.5.
Presence / absence of water leakage was observed after 1 min of kg / cm ² .

Electronic Equipment Telephone FIG. 1A shows an example of a cordless telephone. 1 in FIG.
Is the receiver (speaker), 2 is the transmitter (microphone),
Reference numeral 3 is a transmitter section (ringer section), and 4 is a battery section.

In order to suppress the deterioration of the volume and the sound quality as much as possible and prevent the intrusion of water from the outside, in the parts such as the speaker part 1, the microphone part 2 and the ringer part 3 where sound comes in and goes out.
Use a waterproof ventilation filter. FIG. 1B is an enlarged view of the speaker unit 1, the microphone unit 2, and the ringer unit 3, 5 is a case body, 6 is a speaker, a microphone, or a ringer, 7
Is a waterproof ventilation filter, 8 is an O-ring or rubber, and 9 is an adhesive. By using the oil repellent waterproof ventilation filter of the present invention for the waterproof ventilation filter 7, the service life of the filter can be greatly extended.

Further, when a secondary battery is used as a battery, it is known that gas is generated at the time of overcharging, but this gas is quickly released to the outside and intrusion of water, soapy water, etc. from the outside. To prevent this, the oil repellent waterproof ventilation filter of the present invention is used as the vent filter of the battery case. FIG. 1 (c) is an enlarged view of the battery case portion 4, 5 is a case body, 11 is a battery, 12 is an oil-repellent waterproof ventilation filter, and 13 is an adhesive.

If the camera is made airtight in order to make it waterproof, there is a risk that the equipment will be deformed or the element will be damaged due to changes in the internal pressure due to temperature changes, and it will be difficult to open the lid if the internal pressure drops. Since there are disadvantages such as difficulty in focusing and zooming, a waterproof vent is provided. Figure 2 (a) is an example of this, which is the case of a waterproof camera for daily life.
A vent 22 is provided in 21. FIG. 2B is an enlarged view of the vent, in which 23 is a case body, 24 is an oil-repellent waterproof ventilation filter, 25 is a guard, and 26 is an air hole.

Precision instrument pressure sensor One example of which is shown in FIG. 3 (a). This pressure sensor compares the pressures of the gas to be measured and the atmosphere with the partition wall 31 interposed therebetween. 32 and an inlet 33 for the atmosphere, and the partition wall 31 when the pressure of the measurement gas exceeds a certain pressure.
The electrode 34 has a structure in which the electrode 34 is pressed to detect this.
FIG. 3B is an enlarged view of the air inlet 33, 35 is the case body of the pressure sensor, 36 is an oil-repellent waterproof ventilation filter,
37 is a rubber packing and 38 is an air hole.

Storage Case Storage Case A vent 42 is provided in a part of the storage case 41 as shown in FIG. 4A, and in order to make it waterproof, as shown in the enlarged view of FIG. 4B, the oil repellency according to the present invention. By using the waterproof ventilation filter, it is possible to obtain a waterproof vent which is waterproof and durable against adhesion of oil stains and detergents in the living environment. In the figure, 43 is a case main body, 44 is an oil-repellent waterproof ventilation filter, 45 is an adhesive, and 46 is a ventilation hole.

Battery Case In the battery case, a gas is generated from the inside of the battery and a pressure fluctuation occurs due to a volume change due to a temperature change of the internal air. Therefore, a vent hole is usually provided, but it is dangerous when exposed to water. Therefore, when the oil-repellent waterproof ventilation filter is provided according to the present invention, it becomes possible to safely wash with water and remove stains with a detergent. FIG. 5 (a) shows an example of this, and 51
Is a battery, 52 is a battery case, and 53 is a vent part. Figure 5 (b) is an enlarged view of the vent part, 52 is the battery case body, 54 is an oil repellent waterproof ventilation filter, 55 is a holder, 56 is a washer, and the left side of the oil repellent waterproof ventilation filter 54 is the battery in the figure. Inside the case.

[0026]

According to the present invention, by surface-treating a breathable substrate with an amorphous fluoropolymer solution, the oil repellency can be remarkably improved without impairing the breathability. In particular, stretched porous PTFE membranes and their laminated products are known as waterproof and breathable materials, but since they have little oil repellency by themselves, the waterproof and breathable performance deteriorates when surface active agents, detergents, etc. adhere. However, it was not durable, but by coating with the amorphous fluoropolymer solution according to the present invention, it can have oil repellency without impairing the conventional waterproof and breathable properties. Therefore, in an electronic device with a built-in electronic component, a precision device that requires precision, a storage case that requires waterproofness, etc., it is possible to provide a waterproof ventilation filter that is durable against oily dirt and detergent adhesion. Is great.

[Brief description of drawings]

FIG. 1 is a cross-sectional view and a partially enlarged view of a cordless telephone.

2A and 2B are a cross-sectional view and a partially enlarged view of a life waterproof camera.

FIG. 3 is a sectional view and a partially enlarged view of a pressure sensor.

FIG. 4 is a perspective view and a partially enlarged view of a storage case.

FIG. 5 is a sectional view and a partially enlarged view of a battery case.

[Explanation of symbols]

 1 ... Speaker part 2 ... Microphone part 3 ... Ringer 5 ... Case body 6 ... Speaker, microphone or ringer 7 ... Oil repellent waterproof ventilation filter 8 ... O ring or rubber 9 ... Adhesive 11 ... Battery 12 ... Oil repellent waterproof ventilation Filter 13 ... Adhesive 21 ... Waterproof camera case 22 ... Vent 23 ... Case body 24 ... Oil repellent waterproof ventilation filter 25 ... Guard 26 ... Air hole 31 ... Partition 32 ... Measurement gas inlet 33 ... Atmosphere Inlet 34 ... Electrode 35 ... Pressure sensor case body 36 ... Oil repellent waterproof ventilation filter 37 ... Rubber packing 38 ... Air hole 41 ... Storage case 42 ... Vent 43 ... Case body 44 ... Oil repellent waterproof ventilation filter 45 ... Adhesive Agent 46… Air hole 51… Battery 52… Battery case 53… Vent 54… Oil-repellent waterproof ventilation filter 55… Holder 56… Washer

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Jinichi Wada 1-42-5 Akakutsumi, Setagaya-ku, Tokyo Japan Pangoa Tex Co., Ltd. Main office (72) Inventor Takao Tadakuma 1-442-5 Akakutsumi, Setagaya-ku, Tokyo No. Japan Headquarters Co., Ltd. (72) Inventor Fumihiro Sasaki 123 South of Yoshinaga-cho, Wake-gun, Okayama Japan Gore-Tex Co., Ltd. Okayama Factory

Claims (3)

[Claims] 1. A case of an electronic device having a built-in electronic component is equipped with an oil-repellent waterproof air-permeable filter, and the oil-repellent waterproof air-permeable filter is used as an air-permeable base material with 60 to 90% of perfluoro-2. An electronic device comprising a material containing an amorphous copolymer of 2-dimethyl-1,3-dioxole and 10 to 40 mol% of tetrafluoroethylene. 2. A precision instrument case is equipped with an oil-repellent waterproof air-permeable filter, and the oil-repellent waterproof air-permeable filter is used on an air-permeable base material at 60 to 90% of perfluoro-2.
A precision instrument comprising a material containing an amorphous copolymer of 2-dimethyl-1,3-dioxole and 10 to 40 mol% of tetrafluoroethylene. 3. The main body or lid of the storage case is equipped with an oil-repellent waterproof air-permeable filter, and the oil-repellent waterproof air-permeable filter is used as an air-permeable base material with 60 to 90% of perfluoro-2,2-dimethyl. -1,3-dioxole and 10-4
A storage case made of a material containing an amorphous copolymer of 0 mol% tetrafluoroethylene.