JP3233683B2 - Oil-repellent waterproof ventilation filter products - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to products such as electronic equipment and precision equipment using an oil-repellent waterproof and air-permeable filter.

[0002]

2. Description of the Related Art When waterproofing communication devices such as portable telephones, cordless telephones and intercoms, and electronic devices such as cameras, waterproofing is performed by telephones, zooming and focusing are performed by cameras, and temperature is also reduced by cameras. In order to mitigate the change in the internal pressure due to the change, a vent having a waterproof property is required. In addition, when vents are required in precision equipment such as pressure sensors and pressure switches, waterproofing is required to maintain the performance of precision equipment, and batteries are required to vent gas generated inside and prevent water intrusion. There is a need. In addition, it is necessary to ventilate the inside of the storage case, but there are many cases where it is difficult for water to pass through.

In such a case, a porous polytetrafluoroethylene resin sheet, a nonwoven fabric, a mesh or the like coated with a polytetrafluoroethylene resin is conventionally used as a waterproof gas-permeable membrane (filter). Was.

[0004]

The conventional waterproof air-permeable filter can achieve the purpose of waterproofness and air-permeability, but can be used for liquids containing surfactants such as detergents and shampoos used in ordinary living environments. Even if the oil content is small, the water resistance and air permeability of the filter almost disappear when the oil comes into contact with the filter portion, and there is a problem that the originally required waterproofness and air permeability cannot be obtained.

Therefore, the present invention provides a waterproof gas-permeable filter which imparts oil repellency to a water-permeable gas-permeable filter and is durable even to a liquid containing a surfactant or oil.
An object is to provide an electronic device, a precision device, a storage case, and the like using the same.

[0006]

SUMMARY OF THE INVENTION In order to achieve the above object, the present invention provides an expanded porous polytetrafluoroethylene.
An oil-repellent, water-permeable, air-permeable filter made of a material in which an amorphous fluoropolymer is contained in a gas-permeable base made of an electronic device case containing electronic components, a precision device case, or a storage case body or lid. It is characterized by providing.

[0007] Expanded porous polytetrafluoroethylene
By treating Ranaru breathable base material an amorphous fluoropolymer, without loss of waterproofness, the conventional substrate (conventional substrate Most oil repellency was not) to impart oil repellency was improved from And the amorphous fluoropolymer can retain the breathability of the breathable substrate. In order to maintain the breathability of the breathable substrate, the amorphous copolymer is coated so as not to completely block the air holes.

The air-permeable base material used is hydrophobic.
Stretched porous polytetrafluoroethylene membrane and each
Use a seed laminate. Gurley number is less than 1000 seconds,
It is preferably 600 seconds or less. As a breathable substrate
All stretched porous polytetrafluoroethylene membranes have nominal pores
The diameter is preferably 0.01 to 15 μm. Also special for base material
Of various properties or as a processing aid
Additives (eg, UV stabilizers, colorants, plasticizers, etc.)
Can be included as long as it does not adversely affect the final product
You.

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

[0010] Such an amorphous fluoropolymer is used as a solvent, for example, perfluoro (2-butyltetrahydrofuran) [Sumitomo 3M "Fluorinert FC-7".
5 "), and the resulting solution is used as a treatment liquid for a gas permeable substrate. This solution must be diluted to leave the substrate breathable, and is typically 0.01-5.0.
A concentration of% by weight is preferred.

The method of treating the gas 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, an electronic device refers to an electronic component, a general device including the electronic component, and a communication device such as a telephone, a pager, a transceiver, an intercom, and a microphone, a camera, a video, a radio, a tape recorder, a radio cassette, and a television. AV equipment (especially portable), electric razor, electric toothbrush, clock, various timers, electronic organizer, headphone, various motors, bath control unit, bath foam generator, bathtub cleaning brush, etc. In addition to electronic components such as batteries. Further, precision equipment is not particularly limited, and refers to general equipment requiring high 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. The storage case is a general case for storing various things,
A case for storing a specific object, for example, a battery case may be used.

[0012]

EXAMPLE Production sample 1 of oil-repellent waterproof breathable filter 1 Polytetrafluoroethylene (PTF) as a breathable substrate
E) Film (Gore-Tex film, nominal pore size 1.0 μm,
(Teflon AF1600) from DuPont (dioxol unit is about 65 mol%)
Products) from Sumitomo 3M “Fluorinert FC-7
5 "was coated on a substrate using a solution dissolved at a concentration of 1.0% by weight to obtain a filter sample 1 having the following characteristics.

[0013] wet within 30 minutes unwetted treated product untreated A) Gurley number (seconds) 11 35 B) WEP [kg / cm ² 1.1 1.2 C) engine oil 1h after wetted instantaneously wetting no later wettability ethanol 1h D) polytetrafluoroethylene (PTF in engine oil after deposition of the water resistance 0.5 kg / cm ² 1min No leakage 0 kg / cm ² as leakage sample 2 breathable substrate
E) Film (Gore-Tex film, nominal pore size 1.0 μm,
(Teflon AF2400) from DuPont (a dioxol unit is about 85 mol%)
Products) from Sumitomo 3M “Fluorinert FC-7
5 "was coated on a substrate using a solution dissolved at a concentration 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) Wettable ethanol Not wet after 1 h Instantly wet Engine oil Not wet after 1 h Wet within 30 minutes D) Oil resistance by engine oil 0.5 kg / cm ² Water leakage at 0 kg / cm ² at 1 min No oil leakage Sample 3 Polytetrafluoroethylene (PTF)
E) Film (Gore-Tex film, nominal pore size 3.0 μm,
Film thickness 30 μm) and polypropylene delnet (thickness 0.3 mm).
Using a laminated product with 15 mm non-woven fabric, "Teflon AF1600" (product having a dioxole unit of about 65 mol%) of DuPont as a processing solution was added to "Fluorinert FC-75" of Sumitomo 3M to 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.

The treated product untreated A) Gurley number (seconds) 1.5 0.6 B) WEP [kg / cm ² 0.6 0.5 C) Wettability washed "biobeads" 30 minutes after detergent wet within 10 minutes unwetted "Mamaremon" in the no leakage at leakage of water resistance at pollution ^{0.1kg / cm 2 1min 0kg / cm} 2 by D) detergent wetted within 10 minutes unwetted after 30 minutes, 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 results are expressed in Gurley numbers. The number of Gurleys is 100 cm ³ of air per inch ² (6.45 cm ² ).
It is the time (sec) required to flow under the pressure of 88 inch (124 mm) H ₂ O. ASTM D726-58, TAPPI-T4 as reference standard
60, JIS P8117 and JIS L1096.

B) WEP (Water Intrusion Pressure) Test A water pressure is gradually applied from one side of the sample, and the WEP is applied at a pressure kg / cm ² at which water leakage is confirmed on the opposite side of the sample.
And Water intrusion was read by placing a pH paper on one side of the sample and changing the color of the paper. JIS K6328 as a reference standard,
There is JIS L1092.

C) Wetting test 2 to 3 ml using a pipette or the like on the surface of the sample placed horizontally.
The test liquid was gently dropped in the form of a droplet, and the state of wetting and the presence or absence of permeation were observed by self-view. Generally, a wet sample turns transparent. D) Water resistance after adhering engine oil After adhering engine oil to one side of the whole sample and leaving it to stand naturally for 1 hour, removing adhering oil, water pressure 0.5
The presence or absence of water leakage after 1 min of kg / cm ² was observed.

[0019] An example of a cordless telephone to the electronic device phone Figure 1 (b). In FIG. 1, 1
Is the receiver (speaker), 2 is the transmitter (microphone),
Reference numeral 3 denotes a transmission unit (ringer unit), and reference numeral 4 denotes a battery unit.

At the places where sound enters and exits, such as the speaker section 1, the microphone section 2, the ringer section 3, etc., in order to minimize a decrease in sound volume and sound quality and to prevent water from entering from outside.
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, wherein 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.

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

Camera If the camera is made airtight to make it waterproof, there is a risk that the equipment may be deformed or the element may be damaged due to a change in the internal pressure due to a change in temperature. Since there are disadvantages such as difficulty in focusing and zooming, a waterproof vent is provided. Fig. 2 (a) shows an example of the case, a case of a waterproof camera for living.
FIG. 2B is an enlarged view of the vent, 23 is a case main body, 24 is an oil-repellent waterproof ventilation filter, 25 is a guard, and 26 is an air hole.

[0023] While shows the example in precision equipment pressure sensor 3 (i), the pressure sensor to compare the pressure of the gas and the air to be measured across a partition wall 31, inlet gas to be measured 32 and an inlet 33 for the atmosphere, and when the pressure of the measurement gas exceeds a certain pressure, the partition 31
, And the electrode 34 has a structure for detecting this.
Fig. 3 (b) is an enlarged view of the air inlet 33, 35 is a pressure sensor case body, 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 a storage case 41 as shown in FIG. 4A, and in order to make it waterproof, an oil repellency according to the present invention as shown in an enlarged view of FIG. The use of the waterproof ventilation filter can provide a waterproof vent that is waterproof and durable even in the living environment against oil stains and detergents. In the figure, 43 is a case 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, gas is generated from the inside of the battery, and pressure changes based on a volume change due to a temperature change of the internal air occur. Therefore, it is usual to provide a vent hole. Therefore, if an oil-repellent waterproof ventilation filter is provided according to the present invention, washing with water or cleaning with a detergent can be performed safely. FIG. 5 (a) shows an example of such a case.
Is a battery, 52 is a battery case, and 53 is a vent. Fig. 5 (b) is an enlarged view of the vent part, 52 is a battery case main body, 54 is an oil-repellent waterproof ventilation filter, 55 is a holder, and 56 is a washer. Inside the case.

[0026]

According to the present invention, an expanded porous polytetraf 、
By subjecting a breathable substrate made of fluoroethylene to a surface treatment with an amorphous fluoropolymer solution, oil repellency can be significantly improved without impairing the breathability. In particular, expanded porous PTFE membranes and laminates thereof are known as waterproof and breathable materials. However, since they have almost no oil repellency, when a surfactant, a detergent, etc. adhere, the waterproof and breathable performance is reduced, Although not durable, coating with an amorphous fluoropolymer solution according to the present invention can provide oil repellency without impairing conventional waterproof breathability. Therefore, in an electronic device having a built-in electronic component, a precision device requiring precision, a storage case requiring waterproofness, and the like, an effect of providing a waterproof ventilation filter that is durable against oily dirt and detergent adherence. Is a great thing.

[Brief description of the drawings]

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

FIG. 2 is a cross-sectional view and a partially enlarged view of the 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]

 DESCRIPTION OF SYMBOLS 1 ... Speaker part 2 ... Microphone part 3 ... Ringer 5 ... Case main 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 ... Life waterproof camera case 22 ... Vent 23 ... Case body 24 ... Oil repellent waterproof ventilation filter 25 ... Guard 26 ... Air hole 31 ... Partition wall 32 ... Gas inlet to be measured 33 ... Atmospheric 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 waterproof ventilation filter 45 ... Adhesive Agent 46… Air vent 51… Battery 52… Battery case 53… Vent part 54… Oil repellent waterproof ventilation filter 55… Holder 56… Washer

────────────────────────────────────────────────── ─── Continuing on the front page (72) Inventor Jinichi Wada 1-42-5 Akatsutsumi, Setagaya-ku, Tokyo Japan Japangore-Tex Co., Ltd. (72) Inventor Takao Tadama 1-42-Akatsutsu, Setagaya-ku, Tokyo No. 5 Japangore Tex Co., Ltd. Head Office (72) Inventor Fumihiro Sasaki 123 south of Yoshinaga-cho, Wake-gun, Okayama Prefecture Japangore-Tex Co., Ltd. Okayama Plant (56) References JP-A-5-23652 (JP, A (58) Fields surveyed (Int. Cl. ⁷ , DB name) B01D 39/00-39/20 C08F 34/02

Claims (3)

(57) [Claims] An electronic device having a built-in electronic component is provided with an oil-repellent waterproof air-permeable filter in a case of an electronic device, and the oil-repellent waterproof air-permeable filter is formed of an expanded porous polytetrafluorocarbon.
Perfluoro 60 to 90 percent breathable base material consisting Roechiren ─2,2─ dimethyl ─1,3─ dioxole and 1
An electronic device comprising a material containing an amorphous copolymer of 0 to 40 mol% of tetrafluoroethylene. 2. A precision instrument case is provided with an oil-repellent waterproof gas-permeable filter, and the oil-repellent waterproof gas-permeable filter is formed of an expanded porous polytetrafluoroethylene with a gas permeability of 60 to 50%. A precision instrument comprising a material containing an amorphous copolymer consisting of 90% of perfluoro {2,2-dimethyl} 1,3-dioxole and 10 to 40 mol% of tetrafluoroethylene. 3. An oil-repellent waterproof gas-permeable filter is provided on a main body or a lid of the storage case, and the oil-repellent waterproof gas-permeable filter is made of expanded porous polytetrafluoroethylene.
Ranaru breathable base material 60 to 90% of the perfluoro ─2,
A storage case comprising a material containing an amorphous copolymer of 2-dimethyl-1,3-dioxole and 10 to 40 mol% of tetrafluoroethylene.