TW200401579A - Heat resistant electret material, heat resistant electret using the same, method for manufacturing the same, and electrostatic acoustic sensor - Google Patents

Abstract

A heat resistant electret material including a porous sheet (2) including fluorocarbon resin, which has a porosity of 15-80%, is prepared, and this heat resistant electret material is attached to the surface of the metal plate (3). Furthermore, by attaching a film including fluorocarbon resin onto this porous sheet (2), the surface can be smoothed. Furthermore, after the resin composition including fluorocarbon resin is applied to the surface of the metal plate (3), and the resin composition is foamed, thereby forming a porous resin layer including fluorocarbon resin on the surface of the metal plate (3). Thus, it is possible to provide a heat resistant electret material, a heat resistant electret using the same and the method for manufacturing the same.

Description

200401579 发明 Description of the invention: [Technical field to which the invention belongs] The present invention relates to a material for heat-resistant electrets used in earphones (10ne, headphone), or microphones, and the like. Heat-resistant electret, method for manufacturing the same, and electrostatic type acoustic wave sensor. [Prior technology] In the past, in the electret used in earphones (earphone, headphone), or micro-earphones, a thermoplastic resin film that can form an electret was laminated on a metal sheet, and this was proposed. Method for electretization of resin (see Japanese Patent Document 1). The copolymer then burns this and gold once it has been contacted, especially when it is raised to the point where ^ ^ ^ ^ Fev (FEP) fine particles of organic solvent are coated on a metal plate to form a thin film, and the thin film is used as an electret The method of incorporation (see Japanese Patent Document 2) is a method of electretization in which a spray solution (dispersed with FEp particles) is sprayed on a metal plate, and then electretization is performed (see Japanese Patent Document 3). Japanese Patent Document 1: Japanese Patent Application Laid-Open No. 64_44〇10 Japanese Patent Document 2: Japanese Patent Application Laid-Open No. 1-150795 Japanese Patent Patent Document 3: Japanese Patent Application Laid-Open No. 2000-1 15895 The electret is used to make a micro-headphone current peaking device or a fusion welding (refl0w) device for welding: South temperature will cause the performance of the electret to decrease. This is the problem with the recent lack of M materials. When welding Temperature-around 26 ° C, the function of the electret itself has a serious problem of 200401579. The Ben Sheming system provides a heat-resistant and highly resistant electret material, a resistive sleeve using the electret material, and a method for manufacturing the electret limb, and a method for producing the same, and an electrostatic sonic sensor. Tester. [Summary of the Invention] 3. To provide a material for heat-resistant electrets to solve the year of weakness and invention, it is characterized in that 'is a porous sheet # containing a resin, and the porous sheet is porous. The degree is 15 to 80%. The present invention also provides a heat-resistant electret, characterized in that the heat-resistant electret material is disposed on a surface of a metal plate. The present invention also provides a method for producing a heat-resistant electret, which is characterized in that it is based on Imago & + + t,,, and 'on the other hand, the heat-resistant electret is surface-bonded. Also, a method for manufacturing a heat-resistant electret is provided. The method is based on the fact that the surface of the metal plate is coated with a resin composition containing a fluororesin to make the resin group. Jie private holes, occupants, and products are foamed to form a porous resin layer containing fluororesin on the surface of the metal plate. In addition, the present invention provides a method for manufacturing a heat-resistant electret, which is characterized in that the surface is coated with a resin composition (containing fluororesin and Compared with fluororesin, the resin added is lower than that of fluororesin, and then the tree Yuetian composition is fired to decompose and remove the bucket and the moon and the sun, and the surface of the metal plate A porous resin layer having a right resin + Rt is selected to have a lice resin. In addition, the present invention provides a method for producing __ 接 # # ω κ, a heat-resistant electret, which is characterized by: After coating the powdered fluororesin composition on the surface of the taxi, magma, and scorpion board, it is allowed to be formed. ≫ λ, or ^^ i, the resin composition is fired to A porous resin layer containing a fluororesin is formed on the surface of the metal plate. In addition, the present invention provides an electrostatic acoustic sensor including the heat-resistant electret described above. [Embodiment] The present invention A material for heat-resistant electrets, characterized in that it is porous with a fluororesin The porosity of the porous sheet is 15 ~ 80%, more preferably 50 ~ 80%. In general, the fluororesin is a resin with high heat resistance, and if the porosity is further increased to 1580 / 〇 The porous fluororesin sheet is used as an electret material, which can suppress the decrease of the surface potential of the electret at high temperature and improve the heat resistance of the electret 1. Here, if the porosity is less than 15%, The surface potential of the electret at a high temperature may be greatly reduced. If the porosity is more than 80%, it is difficult to produce a sheet as an electret material. In addition, the representative gas resin is polytetrafluoroethylene. The dazzling point of dilute (PTFE) is about 32rc. If this fluororesin is used, MEMS 8 (μ · 〇⑽⑺) with a processing temperature of about 300 t can be used.

Mechanical Systems) technology to make micro-headphones and the like. Further, the material for a heat-resistant electret of the present invention may be further adhered with a film containing a fluororesin to the two porous sheets. By this, the surface of the electret can be smoothed, and when the electret is used in a micro-headphone or the like, the operation of the vibration plate is not hindered. In the heat-resistant electret material of the present invention, the fluororesin is selected from polytetrafluoroethylene (PTFE), tetrafluoroethylene-perfluoroalkyl vinyl ether copolymer 200401579 (PFA) 'tetrafluoroethylene-hexafluoro Acrylic copolymers (rigid and tetrafluoroethylene-perfluoro f-based vinyl ether (MFA) are at least one group. By using the above-mentioned fluororesin, excellent resistance can be imparted to the product surface. Excellent performance in water repellency, weather resistance, etc. Also, it will not damage the & properties of the electret. Also, the processing of the 'electret's flower is easier.

The dielectric constant and volume resistivity of the porous sheet are respectively 2.1 or less and 1 or more; 0 × 10 Qcm or more. In addition, the lower limit value of the dielectric coefficient is preferably "coefficient -1", which is close to the public thunder of air Α. Moreover, by making it porous, the dielectric coefficient of the fluororesin itself appears to be apparent. The dielectric constant will be lower. &Quot; t2 'The heat-resistant electret of the present invention is characterized in that it is made of a metal material and has the above-mentioned material for the heat-resistant electret. This can provide heat-resistant materials. kdifferent electret. The thickness of the porous sheet is not particularly limited, but it is usually 5 to 4 ... preferably 10 to 5 "m. As long as it is within this range-the characteristics of the electret, while seeking thinning and miniaturization of the electret. As the form of the upper Lt porous sheet, a non-woven cloth, a woven cloth paper, a stretched film, and the like can be used. In addition, for the heat-resistant electret of the present invention, the metal plate is selected from ordinary copper, stainless steel, copper, titanium, zinc-copper, phosphor bronze, and Γ: Γ: two metals and a metal on which these materials f are vapor-deposited. :: 成 = Sex, ^ is better. The reason is that 'these metals are excellent in corrosion resistance, electrical properties, and workability. In the case of using the above metal plate, first use a non-adhered grease, etc. 200401579. Second, the second: the right: the bottom layer treatment to improve the formation of skin media with the porous sheet or the ^ treatment, for example, anodizing , 5 times the production process, and other methods to improve adhesion. It is based on the manufacturing method of metal: heat-resistant electret, which is characterized by, for example, the following: (the material for the heat-resistant electret.) The pair of porous sheet rolls plus ^ and a pair of crimps without light source σ ... are supplied to the metal plate on the roll side, ^ The porosity is only sealed from the '耵 + roll side with heat source and sealed The metal plate is inserted between the crimping roller and the porosity. The working system is 1 to 20 mm to perform thermal compression bonding of the whole body. The metal plate and the porous sheet are ::: The obtained electret is cut to a predetermined size with a laminated board system, and after the polarizing and charging are performed by using a military discharge, etc., the aging process is performed on the earphones _P11_, `` rings, micro earphones, etc. '' Another method for manufacturing a heat-resistant electret is characterized in that 'the surface of a metal plate is coated with a resin composition containing ^ 3 messy resin, and the gas is foamed on the surface of the metal plate. A porous resin layer is formed. That is, 'for example, a gas-containing resin is dissolved with an electrolyte to form an I: composition. A nebulizer or the like is applied to a metal plate and foamed when the resin = is fired, so that a porous resin layer contained on the surface of the metal plate can be formed. In the foaming method, the use of hair The method of soaking d, or the method of firing under reduced pressure, etc. Also, 'the other method of manufacturing the alkaline electret of the present invention is characterized by ^ UU401579, which is based on the centrifugal, After the surface of the board is coated with a resin composition (containing fluororesin and added resin with a low fluororesin and low addition ratio), the resin composition is $ Λ, the heart becomes The added resin is decomposed and removed, and on the surface of the metal plate: a porous resin layer containing a fluororesin is formed. By changing the size and shape of the added resin, the shape of the stone can be arbitrarily controlled. As for the added resin, polyethylene, S, etc. can be used. Because the fluororesin is fired at a temperature close to 400 ° C, the above-mentioned added resin will decompose and disappear during firing to form voids. Another manufacturing method of the invention's heat-resistant electret, which It is characterized in that 'the surface of a metal plate is coated with a resin composition containing powdered fluororesin to form a void, and then the resin composition is fired to form a porous wax containing fluorine resin on the surface of the metal plate. In this method, even without using a foaming agent or adding a resin, & the shape of the porous resin layer can be arbitrarily controlled by changing the size / shape of the powder, such as the thickness of the coating layer. The electrostatic type acoustic wave sensor of the present invention is characterized in that the above-mentioned heat-resistant electret is prepared. The electrostatic type acoustic wave sensor includes, for example, earphones, headphones, micro-earphones, hearing aids, and ultrasonic sensors. (Acceleration sensor), etc. (Examples) The present invention will be described in more detail below using examples and comparative examples (Example 1) A non-woven fabric manufactured by Daikin Industries Co., Ltd. is compacted with a calender roll to reduce the early area. 50g / m2 ptfe This PTFE non-woven fabric is ready to be used as electret 10 200401579 body material. This PTFE non-woven fabric was pressed to a thickness of 0.2 mm with a heating roller, and then the steel plate was cut into 5 Gem in length and 2 ° in width, as in the electret of Example 1. The thermocompression bonding was performed at a temperature of 3 kgf / cm2. The pressure is, for example, a cross-sectional view of the electret produced in this implementation. The electret i # PTFE non-woven fabric 2 and the stainless steel plate formed in this embodiment. (Example 2) A PTFE non-woven fabric with a weight per unit area of 150 and ^ 2 manufactured by Daikin Industries was prepared as a material for electrets. This ρτρΕ non-woven fabric and a stainless steel plate having a thickness of 0.2 mm were heat-pressed and lightly pressed, and then cut into the same size as in Example 1 to obtain the electret of Example 2. The thermocompression bonding was performed at a temperature of 360 ° C and a pressure of 6 kgf / cm2. (Example 3) A PTFE nonwoven fabric having a basis weight of i50 g / m2 manufactured by Daikin Industries was prepared as a material for electrets. This non-woven fabric and a stainless steel sheet having a thickness of 0.2 mm were thermo-compression-bonded with a heating roller, and then cut into the same size as in Example 1 to obtain the electret of Example 3. The hot dust connection was performed at a temperature of 360 ° C and a pressure of 3 kgf / Cm2. (Example 4) A PTFE non-woven fabric having a basis weight of 250 g / m2 manufactured by Daikin Industries was prepared as a material for an electret. This pTFE non-woven fabric and a stainless steel sheet having a thickness of 0.2 mm were thermo-compression-bonded with a heating roller, and then cut into the same size as in Example 1 to obtain the electret of Example 4. The thermocompression bonding was performed at a temperature of 200401579 degrees 360 ° C and a pressure of 3 kgf / cm2. (Example 5) A PTFE paper manufactured by Daikin Industries Co., Ltd., PA-5L "was used as an electret material. This PTFE paper and a stainless steel plate having a thickness of 0.2 mm were thermocompression-bonded with a heating roller, and then cut. The electret of Example 5 was obtained in the same size as that of Example 1. The thermocompression bonding was performed at a temperature of 36 ° C. and a pressure of 6 kgf / cm 2. (Example 6) A PTFE paper manufactured by Daikin Industries was prepared. "PA-5L" was used as the electret material. This PTFE paper was thermocompression bonded to a stainless steel plate with a thickness of 0.2 mm by heating, and then cut into the same size as in Example 1 to obtain the electret of Example 6. Polar body. The thermocompression bonding was performed at a temperature of 360 ° C and a pressure of 3 kgf / cm2. (Example 7) Prepare a thickness of 150 g / m2 PTFE nonwoven fabric made by Daikin Industries and a thickness manufactured by Daikin Industries The sheet laminated with 〆m's pFA film AF-0025 "is used as an electret material. The PTFE non-woven fabric side of this sheet and a stainless steel plate with a thickness of 0.2 mm are used to heat Qin " for thermocompression bonding. , And then cut into the same size as in Example 1 to obtain the electret of Example 7. The thermocompression bonding was performed at a temperature of 34 (TC and a pressure of 3 kgf / cm2.) (Example 8) A TFE nonwoven fabric having a basis weight of 250 g / m2 manufactured by Daikin Industries Co., Ltd. and a thickness of 25 # m manufactured by Daikin Industries Co., Ltd. were prepared. Of PFA thin

12 200401579 Film AF-0025 is laminated as an electret material. The PTFE non-woven fabric side of this sheet and a stainless steel plate having a thickness of 0.2 mm were thermally pressure-bonded with a heating roller, and then cut into the same size as in Example 1 to obtain the electret of Example 8. The thermocompression bonding was performed at a temperature of 34 ° C and a pressure of 3 kgf / cm2. (Comparative Example 1) A film "AF-0050" formed by stacking 3 pieces of pfa film made by Daikin Industries Co., Ltd., was used as an electret. Material: This film is thermally bonded to a stainless steel plate with a thickness of 0_2 mm by a heating roller, and then cut into the same size as in Example 丨 to obtain an electret of a comparative example. The thermal compression bonding is based on The temperature was 360 ° C and the pressure was 3 kgf / cm2. (Comparative Example 2) A film "NF-0050" formed by stacking three FEp films with a thickness of 50 // m manufactured by Daikin Industries was prepared as an electret. Material: This film was thermocompression bonded to a stainless steel plate with a thickness of 0.2mm by a heating roller, and then cut into the same size as in Example 1 to obtain the electret of Comparative Example 2. The thermocompression bonding was performed at a temperature of 360 ° C. And pressure of 3 kgf / cm2. Lu (Comparative Example 3) A film "920-UL" formed by stacking 6 pTFE films with a thickness of 25 // m manufactured by Nitto Denko Corporation was used as the electret material. This film was thermo-compression-bonded with a stainless steel plate having a thickness of 0.2 mm by a heating roller, and then cut into the same shape as in Example 1. It is small enough to obtain the electret of Comparative Example 3. The thermocompression bonding was performed at a temperature of 360 ° C and a pressure of 3 kgf / cm2. (Comparative Example 4) 13 200401579 A PFA with a thickness of 25 // m manufactured by Daikin Industries was prepared. The film "AF-0025" was used as an electret material. This film was thermocompression-bonded with a stainless steel plate having a thickness of 2 · 2τηι with a heating roller, and then cut into the same size as in Example 1 to obtain a film of Comparative Example 4. Polar body. The thermocompression bonding was performed at a temperature of 360 ° C and a pressure of 3 kgf / cm2. (Comparative Example 5) A 25 // m thick FEP film NF-0025 "manufactured by Daikin Industries was prepared as an electret Material. This film and the thickness of stainless steel plate were heat-pressed with a heating roller, and then cut to the same size as in Example 丨 to obtain the electret of Comparative Example 5. The heat-pressed connection was at a temperature of 33 °. And pressure of 3 kgf / cm2. (Comparative Example 6)

A 25mm thick pTFE film "920-UL" manufactured by Yoto Denko Corporation is to be used as an electret material. This film is thermocompression bonded to a stainless steel plate with a thickness of 0.2 legs by a heating roller. Then cut into the same size as in Example 1 to obtain the electret of Comparative Example 6. The thermocompression bonding was performed at a temperature of me and a pressure of 3 kgf / Cm2. The thickness and surface of the electrets of Comparative Examples 1 to 6 Roughness and Porosity Secondly, the above-mentioned Examples 1 to 8 were used to measure the material thickness of the electret and the residual potential of the surface potential of the electret after thermocompression bonding. The surface of the material for the electret is a surface roughness meter "㈣㈣" made by Mitutoyo Corporation. The porosity of the material for the electret is an electronic display manufactured by Japan 14 200401579 23 80N / EMAX_7000 ”was measured from an electron microscope photograph. The residual rate of the surface potential of the electret was measured in the following manner. First, the sample was polarized with a negative corona discharge at a temperature of 25 ° C, and immediately afterwards, the surface potential was measured with a surface potentiometer "modei 3 44" manufactured by Trek. Next, after holding for 10 minutes at 270 t or 300 t, the surface potential was measured in the same manner. Then, based on the surface potential of the electret just after the polarization treatment (100%), and the surface potential after 27 minutes (Kc or 3⑽.c) as the relative value (%), the surface potential remains rate.

The above measurement results are shown in Table i. Fig. 2 shows the relationship between the surface potential residual rate and temperature in Example 3 and Comparative Examples 4 to 6.

It is clear from Table 1 that the tables of Examples 1 to 6 are superior to Comparative Examples 1 to 6. In addition, examples of the surface potential residual ratio phase 7 and Example 8

15 200401579 Difference at 300 ° C. The surface potential residual rate is better than that of Comparative Example j. From Examples 1 to 6, it can be seen that the surface potential residual rate is inevitably increased: the higher the porosity of the material for the polar body, the better. Sheep'4 is ^ liter. In particular, the porosity is 50% or more. Although the surface roughness of Example 7 and Example 8 is comparative to that of Comparative Example, it is because the inside has the same potential reduction. It is possible to suppress the surface and the thickness of the electret material. Ding is not so pleased that the surface potential remains effective. As described above, the present invention uses „, raA ^ ^ • belongs to the material for surface-adhesion resistant electrets (for fluororesin-containing, ... Sheet, and the porosity of the multi-class secret material is M ~ 80%), it can be improved-an electret with excellent heat resistance to use various electrostatic sonic sensors of the electret, industrial value局 [Simplified description of the diagram] (1) Part of the diagram is a cross-sectional view of the electret produced according to the embodiment. Figure 2 shows the electret ancestral survival rate and temperature of the electret. Relation diagram 〇 (一) Explanation of component symbols 1 Electret 2 PTFE non-woven 16 200401579

Claims (1)

200401579 The scope of patent application: 1 · -Heat-resistant electret material 'is characterized in that it is a fluororesin-containing porous sheet' The porous sheet has a porosity of 15 ~ _. Ichiyo / TJ Magazine Bamboo, with less holes in it! The raw sheet is further advanced—adhered to the film containing gas resin. 3. If the material for heat-resistant electrets in the scope of the patent application is applied, 'wherein' the fluororesin is selected from the polymer Siwengyue ^ κ tetramurethylene (PTFE), tetrafluoroethylene-perfluoroalkyl vinyl ether copolymer At least one of the group consisting of PFA, tetramethylene ethylene-hexamethylene propylene copolymer (FEP), and tetrafluoroethylene-methylene vinyl ether (MFA). 4. If the materials for application range 1 to 3 are used, 'wherein', the porous sheet is 2_1 or less and h0 > < 1016, which is characterized in any one of the items 5. · One kind of heat-resistant electret Decent, surface configuration patent application scope! ~ 4 materials. The coefficient of heat-resistant electret of any one of the above items and the volume resistivity Ω cm or more. 'It is used for the heat-resistant electret of the sheet of metal plate. The metal-resistant plate of item 5 of the scope of patent application is selected from brass, Shao, and non-recorded steel: including copper, all of them, and miscellaneous contributions Titanium, white copper, phosphorous, the metal of material 7 and the steam bond are formed by this kind of soil. . A system of heat-resistant electret! + The spear and method of a metal plate are characterized in that they are attached to the surface of the plate and are suitable for the material of "electret." The method for producing a heat-resistant species and heat-resistant electret according to any of 1zheng 1f1, It is characterized in that the surface of the metal plate is coated with a resin composition containing Wong ^ r ^ M on the surface of 18 200401579, and a porous resin layer is formed on the surface of the metal plate. The manufacturing method of a polar body is characterized in that a resin composition is coated on the surface of a stand-up plate, 'these +1 each have a messy resin, and the resin composition is decomposed at a lower temperature than that of Gu Zhiyue,' after the resin composition. It is formed to decompose and remove the added resin, and to form a porous resin layer with a fluororesin on the surface of the metal plate. 10. A method for producing a heat-resistant electret, characterized in that After the surface of the metal plate is coated with a resin composition containing a powdery fluororesin to form a void, the m㈣ is fired to form a porous resin layer containing the fluororesin on the surface of the metal plate. The method for manufacturing a heat-resistant electret according to any one of items 8 to 10, wherein the porosity of the porous resin layer is 15 to 80%. 12 · —An electrostatic sonic sensor, which is characterized in that The reason is that it has the heat-resistant electret with the number 5 or 6 of the applied patent.