Diaphragm for audio components

Abstract

A single-layer film for acoustic components with hardening properties. According to the present invention, a film for acoustic components can be provided that improves shape retention before molding, shapeability during molding, and mold conformability, and prevents the film from adhering to molds such as metal molds during molding, and can be peeled off from the release film without damage when peeling off the release film before molding.

Description

[Technical Field]

[0001] This invention relates to a membrane for an audio component, an audio component, a diaphragm, an audio transducer, a method for manufacturing a membrane for an audio component, a polysiloxane membrane, a molded article, a method for manufacturing a polysiloxane membrane, a membrane, a method for manufacturing a membrane, a method for manufacturing an audio component, and a method for using the membrane in an audio component. [Previous Technology]

[0002] With the widespread use of small electronic devices such as smartphones, PDAs, laptops, DVDs, LCD TVs, digital cameras, and portable music devices, the demand for small speakers (commonly referred to as miniature speakers) or small handsets, and further, microphones, headphones, and other small electronic audio transducers used in these devices is increasing. As diaphragms used in these electronic audio transducers, polyetherimide (PEI) resin and polyetheretherketone (PEEK) resin are widely used.

[0003] Furthermore, research has begun in recent years on the use of polysiloxane resin in the aforementioned vibratory plates. For example, Patent Document 1 discloses a vibratory plate sheet formed by sequentially stacking a release sheet, a first layer comprising an uncured liquid polysiloxane composition, and a second layer mainly comprising thermoplastic polyurethane, and a method for manufacturing a vibratory plate using the vibratory plate sheet. In Patent Document 1, a vibratory plate is manufactured by placing the vibratory plate sheet in a metal mold and shaping it, and then peeling the release sheet off from the formed product. Because the vibratory plate sheet described in Patent Document 1 uses an uncured liquid polysiloxane composition, it can improve the shapeability during molding and also improve the conformability to the metal mold. [Prior Art Documents] [Patent Documents]

[0004] Patent Document 1: Japanese Patent Application Publication No. 2018-152817 [Summary of the Invention]

[0005] [The problem the invention aims to solve]

[0006] In Patent Document 1, the vibratory plate sheet is formed by placing it in a metal mold with a release film deposited on the first layer containing an uncured liquid polysiloxane composition. Therefore, the release film needs to be peeled off after forming. However, due to the heating and pressure during forming, the release film is often difficult to peel off from the first layer, resulting in reduced workability and difficulty in mass production. Therefore, it is ideal to place the vibratory plate sheet in a mold such as a metal mold after peeling off the release film. However, without a release film, problems arise such as the first layer containing the uncured liquid polysiloxane composition adhering to the metal mold, making it difficult to easily remove the molded product. Furthermore, there is a problem of damage to the first layer containing the uncured liquid polysiloxane composition during the peeling process. Moreover, if the vibratory plate sheet in Patent Document 1 lacks a release film, its shape retention before forming is also reduced.

[0007] Therefore, the first aspect of the present invention aims to provide a film for audio components that improves shape retention during molding and mold conformability, and can be peeled off from the release film without damage when peeling off the release film before molding. Furthermore, the second aspect of the present invention aims to provide a polysiloxane film that improves shape retention before molding and shape retention during molding, and can prevent the film from adhering to the mold during molding. Furthermore, the third aspect of the present invention aims to provide a film for audio components that possesses shape retention before molding, shape retention during molding, and mold conformability, and can be peeled off from the release film without damage when peeling off the release film before molding. Furthermore, the fourth aspect of the present invention aims to provide a film that improves shape retention before molding, shape retention during molding, and mold conformability, and can prevent the film from adhering to molds such as metal molds during molding. [Technical Means for Solving the Problem]

[0008] Through diligent research, the inventors have discovered that the above-mentioned problems can be solved by using a single-layer acoustic component film with curable properties, a single-layer polysiloxane film with curable properties and controlling the static friction coefficient of at least one side, a film with a specific storage modulus, or a multi-layer structure with controlling the static friction coefficient of the outermost / backmost layer and the middle layer having curable properties, and the following invention is finally completed. The main idea of ​​the invention is as follows. [1] A single-layer acoustic component film having curable properties. [2] The acoustic component film described in [1] above has a gel content of 60% to 90% or less. [3] The acoustic component film described in [1] or [2] above has the following viscoelastic properties: (a) The storage modulus E' at a measurement temperature of 20°C is 0.1 MPa to 500 MPa or less. [4] The acoustic component film described in any one of [1] to [3] above has thermosetting properties. [5] The acoustic component membrane described in any one of [1] to [4] above has a cross-linked structure. [6] The acoustic component membrane described in any one of [1] to [5] above has the following viscoelastic properties (b) to (d) in its hardened state: (b) the storage modulus E'20 at a measuring temperature of 20°C is 0.1 MPa or more and 500 MPa or less; (c) the storage modulus E'100 at a measuring temperature of 100°C is 0.1 MPa or more and 500 MPa or less; (d) the ratio of the storage modulus E'100 to the storage modulus E'20 (E'100 / E'20) is 0.2 or more and 1.0 or less. [7] The acoustic component membrane described in any one of [1] to [6] above is a diaphragm membrane. [8] The acoustic component membrane described in any one of [1] to [7] above is a polysiloxane membrane. [9] The acoustic component membrane described in any one of [1] to [8] above has a static friction coefficient of 3 or less on at least one side.

[10] An acoustic component formed by hardening the acoustic component membrane described in any one of [1] to [9] above.

[11] A diaphragm formed by hardening the acoustic component membrane described in any one of [1] to [9] above.

[12] An acoustic transducer comprising the acoustic component described in

[10] above.

[13] An acoustic transducer comprising the diaphragm described in

[11] above.

[14] A method for manufacturing the acoustic component membrane described in any one of [1] to [9] above, comprising a step of irradiating with radiation.

[15] A method for manufacturing the acoustic component membrane described in

[14] above, wherein after irradiating with radiation, a resin layer laminated on a release film is peeled off from the resin layer.

[16] A method for manufacturing a membrane for an acoustic component as described in any one of [1] to [9] above, comprising the steps of: depositing a resin layer between two release films having a surface roughness (Ra) of 0.10 to 6.00 μm; hardening the deposited resin layer; and peeling off at least one release film from the hardened resin layer.

[17] A single-layer polysiloxane film having curability and a static friction coefficient of 3 or less on at least one side.

[18] The polysiloxane film described in

[17] above, having a gel content of 60% to 90%.

[19] The polysiloxane film described in

[17] or

[18] above, having the following viscoelastic properties: (a) a storage modulus E' at a measurement temperature of 20°C of 0.1 MPa to 500 MPa.

[20] The polysiloxane film described in any one of

[17] to

[19] above has thermosetting properties.

[21] The polysiloxane film described in any one of

[17] to

[20] above has a cross-linked structure.

[22] The polysiloxane film described in any one of

[17] to

[21] above has the following viscoelastic properties (b) to (d) in the cured state: (b) the storage modulus E'20 at a measurement temperature of 20°C is 0.1 MPa or more and 500 MPa or less; (c) the storage modulus E'100 at a measurement temperature of 100°C is 0.1 MPa or more and 500 MPa or less; (d) the ratio of the storage modulus E'100 to the storage modulus E'20 (E'100 / E'20) is 0.2 or more and 1.0 or less.

[23] The polysiloxane film described in any of

[17] to

[22] above is a film for an acoustic component.

[24] The polysiloxane film described in any of

[17] to

[23] above is a film for a diaphragm.

[25] A polysiloxane film with a release film attached, comprising the polysiloxane film described in any of

[17] to

[24] above, and a release film disposed on at least one side of the polysiloxane film.

[26] A molded article formed by curing the polysiloxane film described in any of

[17] to

[24] above.

[27] An acoustic component formed by curing the polysiloxane film described in any of

[17] to

[24] above.

[28] A diaphragm formed by curing the polysiloxane film described in any of

[17] to

[24] above.

[29] An audio transducer comprising an audio component as described in

[27] above.

[30] An audio transducer comprising a diaphragm as described in

[28] above.

[31] A method for manufacturing a polysiloxane film as described in any one of

[17] to

[24] above, comprising a step of irradiation with radiation.

[32] A method for manufacturing a polysiloxane film as described in

[31] above, wherein after irradiating a polysiloxane resin layer deposited on a release film with radiation, the release film is peeled off from the polysiloxane resin layer.

[33] A method for manufacturing a polysiloxane film as described in any one of

[17] to

[24] above, comprising the steps of: depositing a polysiloxane layer between two release films having a surface roughness (Ra) of 0.10 to 6.00 μm; hardening the deposited polysiloxane layer; and peeling off at least one release film from the hardened polysiloxane layer.

[34] A film for an acoustic component, which is a curable film and has the following viscoelastic properties: (a) a storage modulus E' of 0.1 MPa to 500 MPa at a temperature of 20°C and a frequency of 10 Hz.

[35] The film for an acoustic component as described in

[34] above has thermosetting properties.

[36] The film for an acoustic component as described in

[34] or

[35] above has a cross-linked structure.

[37] The acoustic component membrane described in any of

[34] to

[36] above has a gel content of 90% or less.

[38] The acoustic component membrane described in any of

[34] to

[37] above is a polysiloxane membrane.

[39] The acoustic component membrane described in any of

[34] to

[38] above has the following viscoelastic properties (b) to (d) in its hardened state: (b) the storage modulus E'20 at a measured temperature of 20°C and a frequency of 10 Hz is 0.1 MPa or more and 500 MPa or less; (c) the storage modulus E'100 at a measured temperature of 100°C and a frequency of 10 Hz is 0.1 MPa or more and 500 MPa or less; (d) the above E'100 / E'20 is 0.4 to 1.0.

[40] A release liner for an acoustic component, comprising an acoustic component membrane as described in any one of

[34] to

[39] above, and a release liner disposed on at least one side of the acoustic component membrane.

[41] An acoustic component formed by curing an acoustic component membrane as described in any one of

[34] to

[40] above.

[42] An acoustic transducer comprising an acoustic component as described in

[41] above.

[43] A method for manufacturing an acoustic component membrane as described in any one of

[34] to

[39] above, comprising a step of curing at least a portion of one or more resin layers constituting the membrane.

[44] A method for manufacturing an acoustic component membrane as described in

[43] above, comprising a step of laminating a cured resin layer with a resin layer having curability.

[45] A membrane comprising an outermost / backmost layer including a hardened resin layer and at least one hardened intermediate layer disposed between the outermost / backmost layers, wherein the static friction coefficient of the outermost / backmost layer is 3 or less.

[46] The membrane described in

[45] above has a gel content of 0% to 90% or less.

[47] The membrane described in

[45] or

[46] above, wherein the gel content of the outermost / backmost layer is 80% or more.

[48] ​​The membrane described in any one of

[45] to

[47] above has the following viscoelastic properties (a): (a) the storage modulus E' at a measurement temperature of 20°C is 0.1 MPa or more and 500 MPa or less.

[49] The membrane described in any one of

[45] to

[48] above has thermosetting properties.

[50] The membrane described in any one of

[45] to

[49] above has a cross-linked structure.

[51] The membrane described in any one of

[45] to

[50] above is a polysiloxane membrane.

[52] The membrane described in any one of

[45] to

[51] above has the following viscoelastic properties (b) in its cured state: (b) the storage modulus E'20 at a measurement temperature of 20°C is 0.1 MPa or more.

[53] The membrane described in any one of

[45] to

[52] above has the following viscoelastic properties (c) to (e) in its hardened state: (c) the storage modulus E'20 at a measuring temperature of 20°C is 0.1 MPa or more and 500 MPa or less; (d) the storage modulus E'100 at a measuring temperature of 100°C is 0.1 MPa or more and 500 MPa or less; (e) the ratio of the storage modulus E'100 to the storage modulus E'20 (E'100 / E'20) is 0.4 or more and 1.0 or less.

[54] The membrane is for acoustic components, and the membrane described in any one of

[45] to

[53] above.

[55] The membrane described in any one of

[45] to

[54] above is a membrane for a diaphragm.

[56] A membrane with a release liner, comprising a membrane as described in any one of

[45] to

[55] above, and a release liner disposed on at least one side of the membrane.

[57] An acoustic component, which is formed by curing a membrane as described in any one of

[45] to

[55] above.

[58] A diaphragm, which is formed by curing a membrane as described in any one of

[45] to

[55] above.

[59] An acoustic transducer, comprising an acoustic component as described in

[57] above.

[60] An acoustic transducer, comprising a diaphragm as described in

[58] above.

[61] A method for manufacturing a membrane as described in any one of

[45] to

[55] above, comprising the step of laminating an uncured or semi-cured intermediate layer between a cured outermost / backmost layer.

[62] A method for manufacturing an acoustic component, wherein a mold is used to shape a membrane for an acoustic component as described in any one of [1] to [9] above, a polysiloxane membrane as described in any one of

[17] to

[24] above, a membrane for an acoustic component as described in any one of

[34] to

[39] above, or a membrane as described in any one of

[45] to

[55] above.

[63] The method for manufacturing an acoustic component as described in

[62] above includes a step of heating the membrane before placing the membrane in the mold.

[64] In the method of manufacturing an acoustic component as described in

[62] or

[63] above, the heating temperature during shaping is 180°C or higher and 260°C or lower.

[65] In the method of manufacturing an acoustic component as described in any one of

[62] to

[64] above, the shaping time is 1 second or higher and 5 minutes or lower.

[66] In the method of manufacturing an acoustic component as described in any one of

[62] to

[65] above, the shaping is performed by any one of pressure forming, vacuum forming, and air-forming.

[67] A method of manufacturing an acoustic component in which the polysiloxane film with release film as described in

[25] above, the acoustic component film with release film as described in

[40] above, or the film with release film as described in

[56] above, is peeled off from the release film, and the polysiloxane film is placed in a mold for shaping.

[68] A method of using a membrane in an acoustic component, wherein the membrane is an acoustic component membrane as described in any one of [1] to [9] above, a polysiloxane membrane as described in any one of

[17] to

[24] above, an acoustic component membrane as described in any one of

[34] to

[39] above, or a membrane as described in any one of

[45] to

[55] above.

[69] An acoustic component having a static friction coefficient of 3 or less on at least one side.

[70] An acoustic component as described in

[69] above, comprising a polysiloxane membrane.

[71] An acoustic component as described in

[69] or

[70] above, having a thickness of 5 μm or more and 500 μm or less.

[72] An acoustic component as described in any one of

[69] to

[71] above, having a cross-linked structure.

[73] The acoustic component described in any one of

[69] to

[72] above has the following viscoelastic properties (b) to (d): (b) the storage modulus E'20 at a measured temperature of 20°C is 0.1 MPa or more and 500 MPa or less; (c) the storage modulus E'100 at a measured temperature of 100°C is 0.1 MPa or more and 500 MPa or less; (d) the ratio of the above storage modulus E'100 to the above storage modulus E'20 (E'100 / E'20) is 0.2 or more and 1.0 or less. [Effects of the Invention].

[0009] According to the present invention, a film for audio components can be provided, which improves shape retention during molding and mold conformability, and can be peeled off from the release film without damage when peeling off the release film before molding (first aspect of the present invention). Furthermore, a polysiloxane film can be provided, which improves shape retention before molding and shape retention during molding, and can prevent the film from adhering to the mold during molding (second aspect of the present invention). Moreover, a film for audio components can be provided, which has shape retention before molding, shape retention during molding, and mold conformability, and can be peeled off from the release film without damage when peeling off the release film before molding (third aspect of the present invention). Furthermore, a film can be provided, which improves shape retention before molding, shape retention during molding, and mold conformability, and can prevent the film from adhering to molds such as metal molds during molding (fourth aspect of the present invention).

Implementation Method

[0011] Hereinafter, embodiments of the present invention will be described, but the present invention is not limited to the embodiments described below as long as it does not depart from its spirit. Furthermore, there is no clear distinction between membranes and sheets; therefore, in the present invention, membranes include sheets.

[0012] [First Embodiment of the Invention] The first embodiment of the present invention is a single-layer membrane for acoustic components that has curable properties. <Membrane for Acoustic Components> The membrane for acoustic components of the present invention (hereinafter sometimes referred to as "this membrane (1)") has curable properties and is single-layered, making it suitable for use in acoustic components. This membrane (1) has curable properties and at least partially uncured portions, thus possessing shape-forming properties. As it is single-layered, it does not have the problem of interlayer delamination.

[0013] <<Gel Content>> The gel content of this membrane (1) is preferably 60% to 90%. If the gel content is within this range, it has moderate curability, and can also achieve a state where the surface is moderately cured and the interior is uncured or semi-cured, thus realizing the effects of the present invention. From the above point of view, the gel content of this membrane (1) is more preferably 60% to 85%, and more preferably 65% ​​to 80%. Furthermore, the gel content is determined by the method described in the examples.

[0014] <<Viscoelastic Properties (Storage Modulus)>> The film (1) preferably has the viscoelastic properties described in (a) below. (a) The storage modulus E' at a temperature of 20°C and a frequency of 10 Hz is 0.1 MPa or more and 500 MPa or less. If the storage modulus E' is 0.1 MPa or more, when the film (1) is laminated onto a release film, it is easy to peel off from the release film due to the moderate hardness of the film (1), and there is no risk of breakage during peeling. Furthermore, it can maintain its shape after peeling off the release film. On the other hand, if the storage modulus E' is 500 MPa or less, the film has moderate softness and good mold conformability or shaping properties during molding. Based on the above viewpoints, E' is preferably 0.5 MPa to 300 MPa, more preferably 0.8 MPa to 200 MPa, further preferably 1.0 MPa to 100 MPa, further preferably 1.2 MPa to 10 MPa, and especially preferably 1.5 MPa to 5 MPa.

[0015] Furthermore, the membrane (1) preferably has the viscoelastic properties of the following (b) to (d) in the cured state. (b) The storage modulus E'20 at a temperature of 20°C and a frequency of 10 Hz is 0.1 MPa or more and 500 MPa or less. (c) The storage modulus E'100 at a temperature of 100°C and a frequency of 10 Hz is 0.1 MPa or more and 500 MPa or less. (d) The above-mentioned E'100 / E'20 is 0.2 or more and 1.0 or less.

[0016] If the storage modulus E'20 at a temperature of 20°C and a frequency of 10 Hz is 0.1 MPa or higher in (b), it has a certain hardness after curing, and therefore, its operability after curing is good. On the other hand, if E'20 is 500 MPa or less, when this membrane (1) is used as a diaphragm, there is a tendency for the acoustic characteristics of the diaphragm, such as sound quality and playability, to be excellent. From the viewpoint of acoustic characteristics and operability after curing, the storage modulus E'20 at 20°C after curing is preferably 1 MPa or more and 400 MPa or less, more preferably 2 MPa or more and 200 MPa or less, more preferably 3 MPa or more and 50 MPa or less, and especially preferably 4 MPa or more and 10 MPa or less.

[0017] Furthermore, if the storage modulus E'100 at a temperature of 100°C and a frequency of 10 Hz is 0.1 MPa or more and 500 MPa or less, then the heat resistance is good, and excellent acoustic characteristics are expected even in high-temperature environments. From the viewpoint of acoustic characteristics and operability after curing, the storage modulus E'100 is more preferably 1 MPa or more and 400 MPa or less, more preferably 2 MPa or more and 200 MPa or less, more preferably 3 MPa or more and 50 MPa or less, and even more preferably 3.5 MPa or more and 10 MPa or less.

[0018] Furthermore, by setting the ratio of (d) storage modulus (E'100 / E'20) to within the range of 0.2 to 1.0, there is a tendency for the change in elastic modulus with temperature to be reduced, resulting in good heat resistance. Also, the change in elastic modulus during heating is small; therefore, the sound quality is less likely to deteriorate under high-temperature conditions, and excellent sound reproduction is easily maintained from the low-temperature range to the high-temperature range. From the above perspective, the aforementioned ratio (E'100 / E'20) is preferably 0.25 to 0.99, more preferably 0.3 to 0.97, and even more preferably 0.35 to 0.95. Furthermore, the storage modulus is a value measured using the method described in the examples after being hardened by a simple method of pressing two flat plates under a pressure of 0.2 MPa while heating one side at 200°C for 2 minutes.

[0019] <<Coefficient of Static Friction>> The static friction coefficient of this film (1) is preferably 3 or less on at least one side. By making the static friction coefficient 3 or less, the film has good operability. For example, in the case of a release film, it is easy to peel off from the release film, and there is no risk of damage during peeling. In addition, it is easy to peel off from the metal mold, which can prevent the film from sticking to the mold during molding. In view of the above, the static friction coefficient is preferably 2.8 or less, more preferably 2.5 or less, and even more preferably 2.3 or less, and particularly preferably 2.1 or less. There is no particular limitation on the lower limit of the static friction coefficient. For example, it can be 0.3 or more, or 0.5 or more, or 0.7 or more. The static friction coefficient required above is that at least one side of this film (1) is 3 or less. As for the static friction coefficient of other sides, it can be more than 3 or less than 3. Furthermore, the static friction coefficient is a value obtained by measuring the stainless steel plate (SUS430) by the method described in the embodiment.

[0020] The static friction coefficient can be appropriately adjusted by the film forming method, the film material, the gel content of the surface portion, etc. Specifically, the static friction coefficient can be adjusted by appropriately adjusting the surface shape. For example, by giving the surface portion roughness, the static friction coefficient can be reduced. As a method to adjust the static friction coefficient, various methods such as sandblasting, shot peening, etching, engraving, embossing roller transfer, embossing tape transfer, embossing film transfer, and surface crystallization can be used to give the surface unevenness. The surface shape can also be changed and the static friction coefficient adjusted by adding particles to the film. As a specific form, the resin composition used to form this film (1) is laminated or extruded onto a release film with unevenness on the surface to form a film. By irradiating the release film side with radiation, the surface portion is cross-linked as described above, and the unevenness of the release film is transferred, thereby producing a film with a static friction coefficient of 3 or less.

[0021] <<Tension Elongation at Break>> The tensile elongation at break of this membrane (1) in its cured state is preferably 100% or more, more preferably 200% or more, and even more preferably 300% or more. If the tensile elongation at break is within this range, the toughness of the membrane is improved, thereby making it less prone to breakage due to long-term vibration, and it tends to have excellent durability when used in acoustic components such as diaphragms. Furthermore, the higher the tensile elongation at break, the better, and there is no particular upper limit, usually below 1500%. Furthermore, the tensile elongation at break can be obtained as follows: by measuring the elongation at break of this membrane (1) after curing in an environment of 200 mm / min and 23°C according to the method of JIS K7161:2014, for the direction orthogonal to the resin flow direction.

[0022] This membrane (1) is a curable membrane. As for the type of curing, it can be any type such as photocurable, moisture-curable, or thermocurable, but thermocurable is preferred. By making this membrane (1) thermocurable, it can be cured while being heated and formed, thus its formability is better. Furthermore, since this membrane (1) is curable, its gel content increases by curing treatment such as heating.

[0023] This film (1) preferably has a cross-linked structure. By having a moderate cross-linked structure, it is easy to obtain a film with suitable viscoelastic properties when cross-linked and hardened. In addition, the shape retention before hardening (i.e. before molding) is easily improved. This film (1) may be in a state where the surface is partially cross-linked and the interior is not hardened. Considering the flexibility of the film, the mold-following or shaping properties during molding, the film as a whole is preferably a film with a moderate degree of cross-linking. That is, as for the overall hardness of the film, it is preferably a film that is harder than an uncross-linked film and softer than a fully hardened film. In this invention, the presence or absence of a cross-linked structure can be determined by the presence of trace amounts of unreacted cross-linking agent and the cross-linking agent after reaction (decomposition) in the case of condensation type, and by the presence of vinyl groups participating in the cross-linking reaction in the case of addition type.

[0024] The thickness of the membrane (1) is not particularly limited, but is preferably 5 μm to 500 μm, more preferably 15 μm to 400 μm, and even more preferably 30 μm to 300 μm. If the membrane thickness is within this range, a membrane with a small thickness deviation can be manufactured during the membrane manufacturing process, and a molded product with a suitable thickness for, for example, a vibrating plate can be manufactured.

[0025] This membrane (1) is composed of a resin layer, and the resin constituting the resin layer is preferably a curable resin, and more preferably a thermosetting resin. Among them, preferred specific examples include: epoxy resin, urethane resin, polysiloxane resin, acrylic resin, phenolic resin, unsaturated polyester resin, polyimide resin, melamine resin, etc. These resins can be used alone or in combination of two or more. This membrane (1) is preferably a polysiloxane membrane. If this membrane (1) is a polysiloxane membrane, it has good heat resistance, mechanical strength, etc., and it is easy to meet the above-mentioned viscoelastic properties (a) and (b) to (d). In addition, the elongation at break can be easily adjusted to the above-mentioned required range.

[0026] <<Polysiloxane Film>> The polysiloxane polymer (organopolysiloxane) used in the polysiloxane film has, for example, the structure represented by the following formula (I). RnSiO(4-n) / 2・・・(I) Here, R is a monovalent hydrocarbon group that may be the same or different, substituted or unsubstituted, preferably a monovalent hydrocarbon group with 1 to 12 carbon atoms, more preferably a monovalent hydrocarbon group with 1 to 8 carbon atoms, and n is a positive number of 1.95 to 2.05.

[0027] As R, examples include: alkyl such as methyl, ethyl, propyl, butyl, hexyl and dodecyl, cycloalkyl such as cyclohexyl, alkenyl such as vinyl, allyl, butenyl and hexenyl, aryl such as phenyl and tolyl, aralkyl such as β-phenylpropyl, and chloromethyl, trifluoropropyl and cyanoethyl, etc., in which one or all of the hydrogen atoms bonded to the carbon atom of such groups are substituted with halogen atoms or cyano groups.

[0028] Furthermore, the organopolysiloxane of the present invention preferably has its molecular chain ends capped with trimethylsilyl, dimethylvinyl, dimethylhydroxysilyl, or trivinylsilyl groups. Moreover, the organopolysiloxane preferably has at least two alkenyl groups in its molecule. Specifically, R preferably contains 0.001 mol% to 5 mol%, more preferably 0.005 mol% to 3 mol%, more preferably 0.01 mol% to 1 mol%, and even more preferably 0.02 mol% to 0.5 mol%, and most preferably contains vinyl groups. The organopolysiloxane is substantially linear, but may partially have branches. It may also be a mixture of two or more molecules with different molecular structures.

[0029] The resin composition used to form the polysiloxane is preferably a mimable type containing an organopolysiloxane. The mimable resin composition is non-liquid (e.g., solid or paste) without self-flowing properties in an uncured state (e.g., uncured state before radiation exposure) at room temperature (25°C), but can be uniformly mixed using a mixer described later. Furthermore, resins other than polysiloxanes can also be mixed as the resin in the resin composition used to form the polysiloxane. Also, commercially available products can be used as organopolysiloxanes, including mixtures containing additives such as cerium oxide fillers and silicon oxide fillers in addition to organopolysiloxanes. Specifically, products manufactured by Shin-Etsu Chemical Industry Co., Ltd. under the trade names "KE-5550-U", "KE-597-U", and "KE-594-U" can also be used.

[0030] <<Radiation>> The polysiloxane film preferably forms a semi-crosslinked structure, making it suitable for fabrication by irradiation. The type of radiation is not particularly limited as long as it is within the scope of achieving the effects of this invention; examples include: X-rays, gamma rays, electron beams, beta rays, alpha rays, protons, deuterium nuclei, heavy ions, neutron beams, meson beams, etc. Regarding the radiation dose and irradiation time, it is ideal to adjust them according to the type of radiation to achieve the aforementioned gel fraction and / or storage modulus range.

[0031] (Crosslinking agent) In the resin composition used to form the polysiloxane, in addition to the aforementioned organopolysiloxane, a crosslinking agent may also be formulated, wherein an organic peroxide is preferred. By formulating an organic peroxide, the polysiloxane can be easily hardened during subsequent shaping and other processes. Considering the film's flexibility, mold conformability, or shapeability during molding, a film with a suitable degree of crosslinking is preferred. That is, in terms of hardness, a film that is harder than an uncrosslinked film and softer than a fully hardened film is preferred. For example, a semi-hardened state is preferable to keep the gel fraction within the desired range.

[0032] Examples of organic peroxides include alkyl peroxides such as ditert-tert-butyl peroxide, 2,5-dimethyl-2,5-di(tert-butylperoxy)hexane, and 2,5-dimethyl-2,5-bis(tert-butylperoxy)hexane, and aralkyl peroxides such as 2,4-diisopropylphenyl peroxide. From the viewpoint of crosslinking speed or safety, alkyl peroxides are preferred, especially 2,5-dimethyl-2,5-di(tert-butylperoxy)hexane.

[0033] The amount of organic peroxide in the resin composition used to form the polysiloxane film is preferably 0.01% by mass or more and 10% by mass or less, more preferably 0.03% by mass or more and 5% by mass or less, further preferably 0.05% by mass or more and 4% by mass or less, particularly preferably 0.1% by mass or more and 3% by mass or less, and even more preferably 0.3% by mass or more and 2% by mass or less, based on the total amount of the resin composition. If the amount of organic peroxide is within this range, there is a tendency to safely obtain a composition with a sufficient curing speed.

[0034] (Filling Material) This membrane (1) may contain a filler. Preferably, the filler is cerium oxide, smoky silicon oxide, or precipitated silicon oxide. By containing a filler, the mechanical properties of the membrane, such as storage modulus or elongation at break, can be set within a suitable range. Furthermore, by using a filler, the viscosity or hardness of the resin composition can be easily adjusted, and the flowability or secondary processing properties of the resin composition can be easily optimized. Moreover, it has the advantage that the hardness can be appropriately adjusted according to the design of the acoustic components or the acoustic characteristics. In addition, the filler constitutes part of the gel component when the gel fraction is measured, and the gel fraction of this membrane (1) is higher due to the presence of the filler. Even if the gel fraction is higher due to the presence of the filler, the hardness of this membrane (1) can be increased in the same way as when the gel fraction is increased by crosslinking.

[0035] The content of filler in the resin composition used to form the membrane (1) is based on the total amount of the resin composition, for example, 10% by mass or more and 50% by mass or less, preferably 15% by mass or more and 40% by mass or less, and more preferably 20% by mass or more and 35% by mass or less. Furthermore, the average particle size of the filler is, for example, 0.01 μm or more and 20 μm or less, preferably 0.1 μm or more and 10 μm or less, and more preferably 0.5 μm or more and 5 μm or less. The average particle size of the filler can be determined using a particle size distribution measuring device based on laser diffraction or the like, as the median particle size (D50).

[0036] The resin composition used to form this film (1) may contain various additives such as heat stabilizers, antioxidants, ultraviolet absorbers, light stabilizers, antibacterial and antifungal agents, antistatic agents, lubricants, pigments, dyes, flame retardants, and impact modifiers within the range of non-destructive effects.

[0037] <Membrane with Release Film> This membrane (1) can also be used as a membrane with release film attached. The membrane with release film attached has the above-mentioned membrane (1) and a release film disposed on at least one side of the membrane (1). Furthermore, in the membrane with release film attached, it is preferable to have release films disposed on both sides of the membrane (1).

[0038] The release film can be a resin film, or a resin film having a release layer formed by at least one side being treated with a release layer. When the release film has a release layer, it is preferable to deposit the release film onto the film (1) in such a way that the release layer contacts the film (1). Examples of resins used as the release film include: polyolefin resins such as polypropylene, acrylic resins, polystyrene resins, polyacetal resins, polyamide resins, polyester resins, polycarbonate resins, ABS resins, polyetheretherketone resins, etc. Among these, polyester resins are preferred, and polyethylene terephthalate resins are preferred. The thickness of the release film is not particularly limited, but is preferably 5 μm or more and 150 μm or less, more preferably 7 μm or more and 120 μm or less, and even more preferably 10 μm or more and 100 μm or less, and particularly preferably 10 μm or more and 80 μm or less.

[0039] This film (1) is protected by a release film. Therefore, damage to this film (1) is prevented during transportation, etc. Furthermore, the release film can be the release film deposited during the manufacture of this film (1), or a release film can be deposited on the manufactured film (1). Also, this film (1) can be formed by, for example, shaping as described below, but during forming, it is advisable to peel the release film from this film (1) and place it in a mold such as a metal mold. At this time, this film (1) can be peeled off from the release film without damage.

[0040] <<Manufacturing Method of This Film (1)>> This film (1) can be formed by a general molding method, such as extrusion molding. A resin composition for forming the film is obtained by mixing, etc., as follows, and the resin composition is formed by extrusion molding, etc. Furthermore, in order to adjust the static friction coefficient of this film (1) to 3 or less, post-processing such as embossing can be performed on the film as described above. Also, a release film with unevenness can be used, and the resin composition can be laminated between or on the release film to obtain this film (1) with a static friction coefficient adjusted to 3 or less.

[0041] More specifically, the following method is preferably described. The method for manufacturing this membrane (1) (membrane for acoustic components) includes the following steps: depositing a resin layer between two release films with a surface roughness (Ra) of 0.10 to 6.00 μm; hardening the deposited resin layer; and peeling off at least one release film from the hardened resin layer. Here, the surface roughness (Ra) is measured by the method described in the examples.

[0042] There are no particular limitations on the resin compositions. For example, they can be obtained by mixing the materials constituting the resin composition. The mixing machine used for mixing can be a known mixing machine such as a single-shaft or twin-shaft extruder, a two-roll or three-roll calender, a roller mill, a plastomill, a Bamboo mixer, a kneader, or a planetary mixer. The mixing temperature is adjusted appropriately according to the type or mixing ratio of the resin, and the presence or type of additives. To inhibit cross-linking (hardening) and moderately reduce the resin viscosity for easy mixing, a temperature of 20°C to 150°C is preferred, more preferably 30°C to 140°C, further preferably 40°C to 130°C, particularly preferably 50°C to 120°C, and especially preferably 60°C to 110°C. The mixing time is sufficient to achieve a uniform mixing of the materials constituting the resin composition, for example, from a few minutes to a few hours, preferably from 5 minutes to 1 hour.

[0043] This membrane (1) can be partially hardened by heating, light irradiation, moisture application, or a combination of these treatments on the membrane obtained as described above. In this invention, it is preferable to use radiation to facilitate easy adjustment of membrane properties and to enable mass production at a faster speed. That is, the manufacturing method of this membrane (1) preferably includes the step of irradiation. Furthermore, when it has the form of a release film, it is preferable to include the step of irradiating the resin layer deposited on the release film with radiation and then peeling the release film off the resin layer.

[0044] <Molded Article> This film (1) can be molded into a molded article by forming and hardening it using a mold such as a metal mold. Typically, it is suitable to be molded into various molded articles by mold forming. It is suitable to be hardened according to the characteristics of this film (1), and it is suitable to be hardened by heating, light irradiation, moisture application or a combination of these treatments, preferably by heating. This film (1) can be used as a diaphragm membrane, and molded articles including this film (1) can be used in particular as acoustic components such as diaphragms.

[0045] In this invention, the gel fraction of the molded article obtained from the above-described film is preferably 80% or more. If the gel fraction is 80% or more, it is easy to obtain a molded article with a storage modulus and mechanical strength suitable for acoustic components. The gel fraction of the molded article is more preferably 85% or more, and even more preferably 90% or more. Furthermore, there is no particular limitation on the upper limit of the gel fraction of the molded article; it can be 100% or less, generally below 100%, for example, 99% or less. Moreover, the gel fraction of the molded article refers to the gel fraction of the entire molded article, and it is advisable to take samples evenly in the thickness direction of the molded article for measurement. The detailed method for measuring the gel fraction is as described in the examples.

[0046] <<Method for Manufacturing Molded Article>> Molded articles can be obtained using this film (1). Hereinafter, a method for manufacturing molded articles using this film (1) will be described. When a molded article is obtained from this film (1), it is preferable to perform at least the following steps 1 and 2. Step 1: Heating the film (1), forming it using a mold, and hardening the film (1) Step 2: Peeling the formed and hardened film (1) (i.e., the molded article) from the mold.

[0047] The following describes each step in more detail. (Step 1) In step 1, the film (1) is heated, shaped using a mold, and the film (1) is hardened to form a molded article. The molded article is preferably shaped using a mold to form the desired shape. The forming in step 1 is not particularly limited, and can be carried out by any forming method such as vacuum forming, air forming, or pressure forming. Among these, pressure forming is preferred in terms of the ease of forming.

[0048] As a mold, a corresponding mold can be prepared according to the molding method, and it is advisable to set the mold with concave and convex shapes corresponding to the shape of the molded article being manufactured. Typically, a metal mold (metal mold) is used as the mold, but a resin mold can also be used. For example, as described below, if the molded article (vibrating plate) has at least one part that is domed or conical, it is advisable to set the mold with concave and convex shapes corresponding to the dome or cone. Furthermore, when the surface of the molded article (vibrating plate) has a tangential edge, it is advisable to set the mold with concave and convex shapes corresponding to the tangential edge.

[0049] As described above, this film (1) is sometimes attached with a release film. As described above, this film (1) is preferably placed in the mold after the release film is peeled off.

[0050] In step 1, the heated film (1) can be shaped using a mold. For example, the film (1) placed on the mold can be shaped by heating while the mold is in place, or the preheated film (1) can be placed on the mold and then shaped by the mold. These methods can also be combined. Furthermore, the film (1) can be heated by any method. For example, when heating the film placed on the mold, the mold can be heated to utilize the heat conduction, or other methods can be used for heating.

[0051] The heating temperature during shaping or hardening is preferably 180°C to 260°C, more preferably 190°C to 250°C, and even more preferably 200°C to 240°C. If the temperature during shaping or hardening is within this range, there is a tendency for the film (1) to harden at a sufficient rate without deforming due to thermal melting.

[0052] The forming time is preferably 1 second to 5 minutes, more preferably 5 seconds to 4 minutes, further preferably 10 seconds to 3 minutes, and even more preferably 20 seconds to 2 minutes. If the heat treatment time during forming is within this range, there is a tendency for sufficient hardening while maintaining productivity. Furthermore, the film (1) is preferably formed and hardened at the same time, but there is no particular limitation, and it may also be hardened after forming. Furthermore, the forming time refers to the time from forming to hardening of the film (1) in the mold, excluding the mold movement time before forming begins and after forming ends, or the time when demolding the laminate.

[0053] (Step 2) In step 2, the film (1) formed and hardened in step 1 is peeled off from the mold to obtain a molded article. In this invention, since the gel fraction of the film (1) does not reach a certain value, its shapeability is high, and the film's conformity to the mold is high. Therefore, the molded article can be manufactured with high forming accuracy. Furthermore, since the film (1) has specific viscoelastic properties, its shape retention is high and its operability is good. Moreover, it can be peeled off without damage when peeling off the release film, maintaining the film shape and easily placed in the metal mold. In addition, by not depositing the release film, the step of peeling the release film off the molded article can be omitted, thus making mass production easy.

[0054] <Application> The membrane of the present invention is preferably used in audio components. Specifically, it is preferably used as a membrane for audio components, and more particularly as a membrane for diaphragms. The audio component of the present invention, such as a diaphragm, is preferably formed by hardening the membrane (1), and more particularly, it preferably includes the above-described molded article. The audio component is more preferably a diaphragm, specifically a speaker diaphragm, and more particularly preferably used as a miniature speaker diaphragm for mobile phones, etc.

[0055] <<Audio Component>> By properly shaping and hardening this membrane (1), various audio components such as diaphragms can be manufactured. The audio component preferably has, for example, at least a portion of it having a dome or cone shape. Furthermore, the audio component may have tangent edges on its surface. When it has a dome or cone shape, or has tangent edges, the audio component is preferably used as a diaphragm, and more preferably as a loudspeaker diaphragm.

[0056] A preferred embodiment is an acoustic component possessing the characteristics of this film. That is, the static friction coefficient of one side of the acoustic component formed using this film, especially the side in contact with the metal mold, can be set to 3 or less, thereby facilitating peeling from the metal mold. The preferred range of the static friction coefficient is as described above. Furthermore, an acoustic component formed from this film, which is a single-layer film, has the advantage of not having interlayer delamination problems. Moreover, an acoustic component formed from this film, which is a polysiloxane film, has good heat resistance, mechanical strength, etc., easily meets the viscoelastic properties (a) and (b) to (d) suitable for acoustic components, and the elongation at break can also be easily adjusted to the required range described above. Specifically, (b) the storage modulus E'20 at a measurement temperature of 20°C is 0.1 MPa to 500 MPa, (c) the storage modulus E'100 at a measurement temperature of 100°C is 0.1 MPa to 500 MPa, and (d) the ratio of the storage modulus E'100 to the storage modulus E'20 (E'100 / E'20) is 0.2 to 1.0. Furthermore, the thickness of the acoustic component can be set to 5 μm to 500 μm, thereby enabling the acoustic component, such as a diaphragm, to obtain good acoustic characteristics. Moreover, by giving the acoustic component a cross-linked structure, the aforementioned viscoelastic properties (b) to (d) are easily satisfied.

[0057] <<Vibrating Plate>> In more detail, the shape of the vibrating plate is not particularly limited; it can be any shape, such as circular, oval, or egg-shaped. Furthermore, a vibrating plate generally has a main body that vibrates in response to electrical signals, etc., and an edge surrounding the main body. The main body of the vibrating plate is usually supported by the edge. As described above, the shape of the vibrating plate can be domed, conical, or a combination of these shapes, or other shapes used for vibrating plates.

[0058] At least a part of the acoustic component can be formed by this membrane (1). For example, the main body of the diaphragm can be formed by this membrane (1), and the edge of the diaphragm can be formed by other components; or the edge can be formed by this membrane (1), and the main body can be formed by other components. Of course, the main body and the edge can also be integrally formed by this membrane (1), or the entire diaphragm can be formed by this membrane (1).

[0059] FIG1 is a diagram showing the structure of a diaphragm 1 according to one embodiment of the present invention. It is a cross-sectional view obtained by cutting the circular diaphragm 1 along a plane passing through the center line of the circle from a top view. The diaphragm 1 is a diaphragm for a miniature loudspeaker. As shown in FIG1, the diaphragm 1 has a recessed portion 1b mounted on the voice coil 2, a peripheral portion (edge) 1c, and an external attachment portion 1d attached to the frame, etc., with the dome (body) 1a as the center.

[0060] FIG2 is a diagram showing the structure of a diaphragm 11 according to another embodiment of the present invention. It is a cross-sectional view obtained by cutting the circular diaphragm 11 along a plane passing through the center line of the circle from a top view. The diaphragm 11 is a diaphragm for a miniature loudspeaker. As shown in FIG2, the diaphragm 11 has a recessed portion 11b for mounting the voice coil 2, a conical portion 11j for mounting the voice coil 2, and a peripheral portion (edge) 11c, with a dome-shaped portion 11a as the center. As illustrated by the diaphragm 11, a portion of the diaphragm can be machined into a dome shape, and the other portions can be machined into a conical shape. Furthermore, the peripheral portion 11c of the diaphragm 11 can be directly mounted to a frame or the like, or it can be mounted to a frame or the like via other components.

[0061] As described above, tangent edges can be formed on the surface of the vibrating plate. The cross-sectional shape of the tangent edges is preferably formed by, for example, a V-shaped groove. FIG3 shows a top view of a vibrating plate 21 according to another embodiment of the present invention. The vibrating plate 21 has a tangent edge portion 21g with a plurality of tangent edges 21e formed on the outer periphery of the circular dome (body) 21a, and a tangent edge portion 21h with a plurality of tangent edges 21f formed on the outer periphery of the tangent edge portion 21g. Furthermore, FIG3 shows an example of two tangent edge portions arranged radially, but only one tangent edge portion may be arranged radially, or more than three tangent edge portions may be arranged.

[0062] Furthermore, as described above, the diaphragm is a loudspeaker diaphragm, and more preferably a miniature loudspeaker diaphragm. From the viewpoint of suitability for use as a miniature loudspeaker diaphragm, the size of the diaphragm should preferably be 25 mm or less, more preferably 20 mm or less, and the maximum diameter should be 5 mm or more. Furthermore, the term "maximum diameter" refers to the diameter when the diaphragm is circular, and the major diameter when it is oval or egg-shaped.

[0063] The vibrating plate can be formed solely from this membrane (1), or it can be formed from a composite material of this membrane (1) and other components. For example, as described above, any part of the edge or the main body can be formed from other components.

[0064] Furthermore, in order to improve the secondary processing suitability or dust resistance of the diaphragm, or to adjust or enhance its acoustic characteristics, the surface of the diaphragm may be appropriately coated with an antistatic agent, or subjected to metal vapor deposition or sputtering, or colored (black or white, etc.). Furthermore, it may also be appropriately laminated with metals such as aluminum, or composited with non-woven fabrics, etc.

[0065] (Audio Converter) The audio converter of the present invention is an audio converter having the above-mentioned audio components, preferably a vibrating plate. Typical audio converters are electrical audio converters, including: speakers, handsets, microphones, headphones, etc. Among these, the audio converter is preferably a speaker, preferably a miniature speaker such as that found in mobile phones.

[0066] [Second Embodiment of the Invention] The second embodiment of the present invention is a single-layer polysiloxane film having curability and a static friction coefficient of 3 or less on at least one side. <Polysiloxane Film> The single-layer polysiloxane film of the present invention (hereinafter sometimes referred to as "this film (2)") is characterized by having curability and a static friction coefficient of 3 or less on at least one side. That is, this film (2) has curability and at least some uncured portions, thus it has shapeability, and since the static friction coefficient is 3 or less, it has good peelability from metal molds or release films. Furthermore, since it is a single layer, there is no problem of interlayer peeling. As a method for producing the polysiloxane film of the present invention, that is, a film in the form of a film having curability and a static friction coefficient of 3 or less on at least one side, it is preferred to form a so-called semi-crosslinked structure by irradiation.

[0067] <<Radiation>> The radiation used to manufacture the membrane of the present invention is not particularly limited as long as it is within the scope of achieving the effects of the present invention. Examples include: X-rays, gamma rays, electron beams, beta rays, alpha rays, protons, deuterium nuclei, heavy ions, neutron beams, meson beams, etc. Regarding the radiation dose and radiation irradiation time, it is ideal to adjust them according to the type of radiation to achieve the range of gel fraction and / or storage modulus described below.

[0068] <<Gel Content>> The gel content of this membrane (2) is preferably 60% to 90%. If the gel content is within this range, it has moderate curability, and can also achieve a state where the surface is moderately cured and the interior is uncured or semi-cured, thus realizing the effects of the present invention. From the above point of view, the gel content of this membrane (2) is more preferably 60% to 85%, and more preferably 65% ​​to 80%. Furthermore, the gel content is determined by the method described in the examples.

[0069] The polysiloxane polymer (organopolysiloxane) used in this membrane (2) has, for example, the structure represented by the following formula (I). RnSiO(4-n) / 2・・・(I) Here, R is a monovalent hydrocarbon group that may be the same or different, substituted or unsubstituted, preferably a monovalent hydrocarbon group with 1 to 12 carbon atoms, more preferably a monovalent hydrocarbon group with 1 to 8 carbon atoms, and n is a positive number of 1.95 to 2.05.

[0070] As R, examples include: alkyl such as methyl, ethyl, propyl, butyl, hexyl and dodecyl, cycloalkyl such as cyclohexyl, alkenyl such as vinyl, allyl, butenyl and hexenyl, and chloromethyl, trifluoropropyl and cyanoethyl such as those in which one or all of the hydrogen atoms bonded to the carbon atom are replaced by halogen atoms or cyano groups.

[0071] Furthermore, the organopolysiloxane of the present invention preferably has its molecular chain end capped with trimethylsilyl, dimethylvinyl, dimethylhydroxysilyl, or trivinylsilyl groups. Moreover, the organopolysiloxane preferably has at least two alkenyl groups in its molecule. Specifically, R preferably contains 0.001 mol% to 5 mol%, more preferably 0.005 mol% to 3 mol%, more preferably 0.01 mol% to 1 mol%, and even more preferably 0.02 mol% to 0.5 mol%, and most preferably contains vinyl groups. The organopolysiloxane is substantially linear, but may partially have branches. It may also be a mixture of two or more molecules with different molecular structures.

[0072] <Coefficient of Static Friction> The film (2) is characterized in that the coefficient of static friction on at least one side is 3 or less. By making the coefficient of static friction 3 or less, the film has good operability. For example, in the case of a release film, it is easy to peel off from the release film, and there is no risk of damage during peeling. It is also easy to peel off from the metal mold, which can prevent the film from sticking to the mold during molding. In view of the above, the coefficient of static friction is preferably 2.8 or less, more preferably 2.5 or less, and even more preferably 2.3 or less, and particularly preferably 2.1 or less. There is no particular limitation on the lower limit of the coefficient of static friction. For example, it can be 0.3 or more, or 0.5 or more, or 0.7 or more. The required coefficient of static friction is that at least one side of the film (2) is 3 or less. As for the coefficient of static friction on other sides, it can be more than 3 or less than 3. Furthermore, the coefficient of static friction is a value obtained by measuring the stainless steel plate (SUS430) by the method described in the embodiment.

[0073] The static friction coefficient can be appropriately adjusted by the film forming method, the film material, the gel content of the surface portion, etc. Specifically, the static friction coefficient can be adjusted by appropriately adjusting the surface shape. For example, by giving the surface portion roughness, the static friction coefficient can be reduced. As a method to adjust the static friction coefficient, various methods such as sandblasting, shot peening, etching, engraving, embossing roller transfer, embossing tape transfer, embossing film transfer, and surface crystallization can be used to give the surface unevenness. The surface shape can also be changed and the static friction coefficient adjusted by adding particles to the film. As a specific form, the resin composition used to form this film (2) is laminated or extruded onto a release film with unevenness on the surface to form a film. By irradiating the release film side with radiation, the surface portion is cross-linked as described above, and the unevenness of the release film is transferred, thereby producing a film with a static friction coefficient of 3 or less.

[0074] <Viscoelastic Properties (Storage Modulus)> The film (2) preferably has the viscoelastic properties described in (a) below. (a) The storage modulus E' at a temperature of 20°C and a frequency of 10 Hz is 0.1 MPa or more and 500 MPa or less. If the storage modulus E' is 0.1 MPa or more, when the film (2) is laminated onto a release film, it is easy to peel off from the release film due to the moderate hardness of the film (2), and there is no risk of breakage during peeling. Furthermore, it can maintain its shape after the release film is peeled off. On the other hand, if the storage modulus E' is 500 MPa or less, the film has moderate softness and good mold conformability or shaping properties during molding. Based on the above viewpoints, E' is preferably 0.5 MPa to 300 MPa, more preferably 0.8 MPa to 200 MPa, further preferably 1.0 MPa to 100 MPa, further preferably 1.2 MPa to 10 MPa, and especially preferably 1.5 MPa to 5 MPa.

[0075] Furthermore, the membrane (2) preferably has the viscoelastic properties of the following (b) to (d) in the cured state. (b) The storage modulus E'20 at a temperature of 20°C and a frequency of 10 Hz is 0.1 MPa or more and 500 MPa or less. (c) The storage modulus E'100 at a temperature of 100°C and a frequency of 10 Hz is 0.1 MPa or more and 500 MPa or less. (d) The above-mentioned E'100 / E'20 is 0.2 or more and 1.0 or less.

[0076] If the storage modulus E'20 at a temperature of 20°C and a frequency of 10 Hz is 0.1 MPa or higher in (b), it has a certain hardness after curing, and therefore, its operability after curing is good. On the other hand, if E'20 is 500 MPa or less, when this membrane (2) is used as a diaphragm, there is a tendency for the acoustic characteristics of the diaphragm, such as sound quality and playability, to be excellent. From the viewpoint of acoustic characteristics and operability after curing, the storage modulus E'20 at 20°C after curing is preferably 1 MPa or more and 400 MPa or less, more preferably 2 MPa or more and 200 MPa or less, more preferably 3 MPa or more and 50 MPa or less, and especially preferably 4 MPa or more and 10 MPa or less.

[0077] Furthermore, if the storage modulus E'100 at a temperature of 100°C and a frequency of 10 Hz is 0.1 MPa or more and 500 MPa or less, then the heat resistance is good, and excellent acoustic characteristics are expected even in high-temperature environments. From the viewpoint of acoustic characteristics and operability after curing, the storage modulus E'100 is more preferably 1 MPa or more and 400 MPa or less, more preferably 2 MPa or more and 200 MPa or less, more preferably 3 MPa or more and 50 MPa or less, and even more preferably 3.5 MPa or more and 10 MPa or less.

[0078] Furthermore, by setting the ratio of (d) storage modulus (E'100 / E'20) to within the range of 0.2 to 1.0, there is a tendency for the change in elastic modulus with temperature to be reduced, resulting in good heat resistance. Also, the change in elastic modulus during heating is small; therefore, the sound quality is less likely to deteriorate under high-temperature conditions, and excellent sound reproduction is easily maintained from the low-temperature range to the high-temperature range. From the above perspective, the ratio (E'100 / E'20) is preferably 0.25 to 0.99, more preferably 0.3 to 0.97, and even more preferably 0.35 to 0.95. Furthermore, the storage modulus is a value measured using the method described in the examples after hardening by a simple method of pressing two flat plates under a pressure of 0.2 MPa while heating one side at 200°C for 2 minutes.

[0079] This membrane (2) is a curable membrane. As for the type of curing, it can be any type such as photocurable, moisture-curable, or thermocurable, but thermocurable is preferred. By making this membrane (2) thermocurable, it can be cured while being heated and formed, thus its formability is better. Furthermore, since this membrane (2) is curable, its gel content increases by curing treatment such as heating.

[0080] This film (2) preferably has a cross-linked structure. By having a moderate cross-linked structure, it is easy to obtain a film with suitable viscoelastic properties when cross-linked and hardened. In addition, the shape retention before hardening (i.e. before molding) is easily improved. As mentioned above, this film (2) can be in a state of partial surface cross-linking and internal unhardened state. Considering the flexibility of the film, the mold-following or shaping properties during molding, the film as a whole is preferably a film with a moderate degree of cross-linking. That is, as for the overall hardness of the film, it is preferably a film that is harder than an uncross-linked film and softer than a fully hardened film. In this invention, the presence or absence of a cross-linked structure can be determined by the presence of trace amounts of unreacted cross-linking agent and the cross-linking agent after reaction (decomposition) in the case of condensation type, and by the presence of vinyl groups participating in the cross-linking reaction in the case of addition type.

[0081] The thickness of the membrane (2) is not particularly limited, but is preferably 5 μm to 500 μm, more preferably 15 μm to 400 μm, and even more preferably 30 μm to 300 μm. If the membrane thickness is within this range, a membrane with a small thickness deviation can be manufactured during the membrane manufacturing step, and a molded product with a suitable thickness for, for example, a vibrating plate can be manufactured.

[0082] <Tensive Elongation at Break> The tensile elongation at break of the membrane (2) in its cured state is preferably 100% or more, more preferably 200% or more, and even more preferably 300% or more. If the tensile elongation at break is within this range, the toughness of the membrane is improved, thereby making it less prone to breakage due to long-term vibration, and tending to have excellent durability when used in acoustic components such as diaphragms. Furthermore, the higher the tensile elongation at break, the better, and there is no particular upper limit, usually below 1500%. Furthermore, the tensile elongation at break can be obtained as follows: by measuring the elongation at break of the cured membrane (2) in the direction orthogonal to the resin flow direction at a tensile speed of 200 mm / min and an environment of 23°C, according to the method of JIS K7161:2014.

[0083] In the resin composition used to form the film (2), in addition to the above-mentioned organopolysiloxane, a crosslinking agent may also be formulated, wherein an organic peroxide is preferred. By formulating an organic peroxide, the film (2) can be easily hardened during subsequent shaping and other processes. Considering the film's flexibility, mold conformability, or shaping properties during molding, a film with a moderate degree of crosslinking is preferred. That is, in terms of hardness, a film that is harder than an uncrosslinked film and softer than a fully hardened film is preferred. For example, a semi-hardened state is preferable so that the gel fraction is within the desired range.

[0084] Examples of organic peroxides include alkyl peroxides such as ditert-tert-butyl peroxide, 2,5-dimethyl-2,5-di(tert-butylperoxy)hexane, and 2,5-dimethyl-2,5-bis(tert-butylperoxy)hexane, and aralkyl peroxides such as 2,4-diisopropylphenyl peroxide. From the viewpoint of crosslinking speed or safety, alkyl peroxides are preferred, especially 2,5-dimethyl-2,5-di(tert-butylperoxy)hexane.

[0085] The amount of organic peroxide in the resin composition used to form the film (2) is preferably 0.01% by mass or more and 10% by mass or less, more preferably 0.03% by mass or more and 5% by mass or less, further preferably 0.05% by mass or more and 4% by mass or less, particularly preferably 0.1% by mass or more and 3% by mass or less, and even more preferably 0.3% by mass or more and 2% by mass or less, based on the total amount of the resin composition. If the amount of organic peroxide is within this range, there is a tendency to safely obtain a composition with a sufficient curing speed.

[0086] The resin composition used to form the membrane (2) is preferably a composable type containing an organopolysiloxane. The composable resin composition is non-liquid (e.g., solid or paste) without self-flowing at room temperature (25°C) in an uncured state (e.g., uncured state before irradiation) but can be uniformly mixed using a mixer described later.

[0087] Furthermore, the resin used in the resin composition for forming this membrane (2) may also be a resin other than polysiloxane (organopolysiloxane). Also, this membrane (2) may contain a filler. Preferably, the filler includes: cerium oxide, smoky silica, or precipitated silica, etc. By including the filler in this membrane (2), it is easy to set the mechanical properties of the membrane, such as storage modulus or elongation at break, within a suitable range. Furthermore, by using the filler, it is easy to adjust the viscosity or hardness of the resin composition, and the flowability or secondary processing properties of the resin composition are easily optimized. Moreover, it has the advantage of easily adjusting the hardness appropriately according to the design of the acoustic components or the acoustic characteristics. Furthermore, the filler constitutes part of the gel component when the gel fraction is measured, and the gel fraction of this membrane (2) is higher due to the presence of the filler. Even if the gel fraction is increased due to the presence of fillers, the hardness of the membrane (2) can be increased in the same way as when the gel fraction is increased by cross-linking.

[0088] The content of filler in the resin composition used to form the membrane (2) is based on the total amount of the resin composition, for example, 10% by mass or more and 50% by mass or less, preferably 15% by mass or more and 40% by mass or less, and more preferably 20% by mass or more and 35% by mass or less. Furthermore, the average particle size of the filler is, for example, 0.01 μm or more and 20 μm or less, preferably 0.1 μm or more and 10 μm or less, and more preferably 0.5 μm or more and 5 μm or less. The average particle size of the filler can be determined using a particle size distribution measuring device based on laser diffraction or the like, as the median particle size (D50).

[0089] The resin composition used to form this film (2) may contain various additives such as heat stabilizers, antioxidants, ultraviolet absorbers, light stabilizers, antibacterial and antifungal agents, antistatic agents, lubricants, pigments, dyes, flame retardants, and impact modifiers within the range of non-destructive effects.

[0090] In this invention, commercially available organopolysiloxanes may also be used. Furthermore, commercially available products containing mixtures of additives such as cerium oxide fillers and silicon oxide fillers, in addition to organopolysiloxanes, may also be used. Specifically, products manufactured by Shin-Etsu Chemical Industry Co., Ltd. under the trade names "KE-5550-U", "KE-597-U", and "KE-594-U" may also be used.

[0091] <Polysiloxane film with release film> This film (2) may be attached with a release film and thus be used as a polysiloxane film with release film. The polysiloxane film with release film has the above-described film (2) and a release film disposed on at least one side of the film (2). Furthermore, in the polysiloxane film with release film, it is preferable to have release films disposed on both sides of the film (2).

[0092] The release film can be a resin film, or a resin film having a release layer formed by at least one side being treated with a release layer. When the release film has a release layer, it is preferable to deposit the release film onto the film (2) in such a way that the release layer contacts the film (2). Examples of resins used as the release film include: polyolefin resins such as polypropylene, acrylic resins, polystyrene resins, polyacetal resins, polyamide resins, polyester resins, polycarbonate resins, ABS resins, polyetheretherketone resins, etc. Among these, polyester resins are preferred, and polyethylene terephthalate resins are preferred. The thickness of the release film is not particularly limited, but is preferably 5 μm or more and 150 μm or less, more preferably 7 μm or more and 120 μm or less, and even more preferably 10 μm or more and 100 μm or less, and particularly preferably 10 μm or more and 80 μm or less.

[0093] This film (2) is protected by a release film. Therefore, damage to this film (2) is prevented during transportation, etc. Furthermore, the release film can be the release film deposited during the manufacture of this film (2), or a release film can be deposited on the manufactured film (2). Also, this film (2) can be shaped by, for example, shaping as described below, but during shaping, it is advisable to peel the release film off the film (2) and place it in a mold such as a metal mold. At this time, this film (2) can be peeled off from the release film without damage.

[0094] <Manufacturing Method of This Film (2)> This film (2) can be formed by a general molding method, such as extrusion molding. A resin composition for forming the film is obtained by mixing or the like in the following manner, and the resin composition is formed by extrusion molding or the like. Furthermore, in order to adjust the static friction coefficient to 3 or less, as described above, the film can be post-processed by embossing or the like. Also, a release film with an uneven surface can be used, and the resin composition can be laminated between or on the release film to obtain this film (2) with a static friction coefficient adjusted to 3 or less.

[0095] More specifically, the following method is preferably described. The manufacturing method of this film (1) (film for acoustic components) includes the following steps: depositing a resin layer between two release films with a surface roughness (Ra) of 0.10 to 6.00 μm; hardening the deposited resin layer; and peeling off at least one of the release films from the hardened resin layer. Here, the surface roughness (Ra) is measured by the method described in the examples.

[0096] There are no particular limitations on the resin compositions. For example, they can be obtained by mixing the materials constituting the resin composition. The mixing machine used for mixing can be a known mixing machine such as a single-shaft or twin-shaft extruder, a two-roll or three-roll calender, a roller mill, a plastomill, a Bamboo mixer, a kneader, or a planetary mixer. The mixing temperature is adjusted appropriately according to the type or mixing ratio of the resin, and the presence or type of additives. To inhibit cross-linking (hardening) and moderately reduce the resin viscosity for easy mixing, a temperature of 20°C to 150°C is preferred, more preferably 30°C to 140°C, further preferably 40°C to 130°C, particularly preferably 50°C to 120°C, and especially preferably 60°C to 110°C. The mixing time is sufficient to achieve a uniform mixing of the materials constituting the resin composition, for example, from a few minutes to a few hours, preferably from 5 minutes to 1 hour.

[0097] This membrane (2) can be partially hardened by heating, light irradiation, moisture application, or a combination of these treatments on the membrane obtained in the manner described above. In this invention, it is preferable to use radiation to facilitate easy adjustment of the membrane properties and to enable mass production at a faster speed. That is, the manufacturing method of this membrane (2) preferably includes the step of irradiation. Furthermore, when it has the form of a release film, it is preferable to include the step of irradiating the polysiloxane layer laminated on the release film with radiation and then peeling the release film off from the polysiloxane layer.

[0098] [Molded Articles] This membrane (2) can be molded into molded articles by forming and hardening it using a mold such as a metal mold. Typically, it is suitable to be molded into various molded articles by molding. It is suitable to harden the membrane (2) according to its properties, preferably by heating, light irradiation, moisture application or a combination of these treatments, preferably by heating. This membrane (2) can be used as a membrane for diaphragms, and molded articles containing this membrane (2) can be used in particular as acoustic components such as diaphragms.

[0099] In this invention, the gel fraction of the molded article obtained from the above-described film is preferably 80% or more. If the gel fraction is 80% or more, it is easy to obtain a molded article with a storage modulus and mechanical strength suitable for acoustic components. The gel fraction of the molded article is more preferably 85% or more, and even more preferably 90% or more. Furthermore, there is no particular limitation on the upper limit of the gel fraction of the molded article; it can be 100% or less, generally below 100%, for example, 99% or less. Moreover, the gel fraction of the molded article refers to the gel fraction of the entire molded article, and it is advisable to take samples evenly in the thickness direction of the molded article for measurement. The detailed method for measuring the gel fraction is as described in the examples.

[0100] <Method for Manufacturing Molded Article> Molded articles can be obtained using this film (2). Hereinafter, a method for manufacturing molded articles using this film (2) will be described. When a molded article is obtained from this film (2), it is preferable to perform at least the following steps 1 and 2. Step 1: Heating the film (2), forming it using a mold, and hardening the film (2) Step 2: Peeling the formed and hardened film (2) (i.e., the molded article) from the mold.

[0101] The following is a more detailed explanation of each step. (Step 1) In step 1, the film (2) is heated, shaped using a mold, and the film (2) is hardened to form a molded article. The molded article is preferably shaped using a mold to form the desired shape. There are no particular limitations on the forming in step 1, and it is preferable to use any forming method such as vacuum forming, air forming, or pressure forming. Among these, pressure forming is preferred in terms of the ease of forming.

[0102] As a mold, a corresponding mold can be prepared according to the molding method. It is advisable to set the mold with concave and convex shapes that correspond to the shape of the molded article being manufactured. Typically, a metal mold (metal mold) is used as the mold, but a resin mold can also be used. For example, as described below, if the molded article (vibrating plate) has at least one part that is domed or conical, it is advisable to set the mold with concave and convex shapes that correspond to the dome or cone shape. Also, when the surface of the molded article (vibrating plate) has tangential edges, it is advisable to set the mold with concave and convex shapes that correspond to the tangential edges.

[0103] As mentioned above, this film (2) is sometimes attached with a release film. As mentioned above, this film (2) is preferably placed in the mold after the release film is peeled off.

[0104] In step 1, the heated film (2) can be shaped using a mold. For example, the film (2) placed on the mold can be shaped by heating while the mold is in place, or the preheated film (2) can be placed on the mold and then shaped by the mold. These methods can also be combined. Furthermore, the film (2) can be heated by any method. For example, when heating the film placed on the mold, the mold can be heated to utilize the heat conduction, or other methods can be used for heating.

[0105] The heating temperature during shaping or hardening is preferably 180°C to 260°C, more preferably 190°C to 250°C, and even more preferably 200°C to 240°C. If the temperature during shaping or hardening is within this range, there is a tendency for the film (2) to harden at a sufficient rate without deforming due to thermal melting.

[0106] The forming time is preferably 1 second to 5 minutes, more preferably 5 seconds to 4 minutes, further preferably 10 seconds to 3 minutes, and even more preferably 20 seconds to 2 minutes. If the heat treatment time during forming is within this range, there is a tendency for sufficient hardening while maintaining productivity. Furthermore, the film (2) is preferably formed and hardened at the same time, but there is no particular limitation, and it may also be hardened after forming. Furthermore, the forming time refers to the time from forming to hardening of the film (2) in the mold, excluding the mold movement time before forming begins and after forming ends, or the time when demolding the laminate.

[0107] (Step 2) In step 2, the film (2) formed and hardened in step 1 is peeled off from the mold to obtain a molded article. In this invention, since the gel fraction of the film (2) does not reach a certain value, its shapeability is high, and the film's conformity to the mold is high. Therefore, the molded article can be manufactured with high forming accuracy. Furthermore, since the film (2) has specific viscoelastic properties, its shape retention is high and its operability is good. Moreover, it can be peeled off without damage when peeling off the release film, maintaining the film shape and easily placed in the metal mold. In addition, by not depositing the release film, the step of peeling the release film off the molded article can be omitted, thus making mass production easy.

[0108] [Applications] The polysiloxane film of the present invention is preferably used in audio components. Specifically, it is preferably used as a film for audio components, and more particularly as a film for diaphragms. The audio component of the present invention, such as a diaphragm, is preferably formed by hardening the film (2), and more particularly, it preferably includes the above-described molded article. The audio component is more preferably a diaphragm, specifically a speaker diaphragm, and more particularly preferably used as a miniature speaker diaphragm for mobile phones, etc.

[0109] By properly shaping this membrane (2), various acoustic components such as diaphragms can be manufactured. The acoustic component preferably has, for example, at least a portion of it having a dome or cone shape. Furthermore, the acoustic component may have tangent edges on its surface. When it has a dome or cone shape, or has tangent edges, the acoustic component is preferably used as a diaphragm, and more preferably as a loudspeaker diaphragm.

[0110] (Vibrating Plate) To provide a more detailed description of the vibrating plate, there are no particular limitations on its shape; it can be any shape, such as circular, oval, or egg-shaped. Furthermore, a vibrating plate generally has a main body that vibrates in response to electrical signals, etc., and an edge surrounding the main body. The main body of the vibrating plate is usually supported by the edge. As mentioned above, the shape of the vibrating plate can be domed, conical, or a combination of these shapes, or other shapes used for vibrating plates.

[0111] At least a part of the acoustic component can be formed by this membrane (2). For example, the main body of the diaphragm can be formed by this membrane (2), and the edge of the diaphragm can be formed by other components; or the edge can be formed by this membrane (2), and the main body can be formed by other components. Of course, the main body and the edge can also be integrally formed by this membrane (2), or the entire diaphragm can be formed by this membrane (2).

[0112] FIG1 is a diagram showing the structure of the vibrating plate 1 according to one embodiment of the present invention, which is the same as that described in this membrane (1). FIG2 is a diagram showing the structure of the vibrating plate 11 according to another embodiment of the present invention, which is the same as that described in this membrane (1). FIG3 is a top view of the vibrating plate 21 according to another embodiment of the present invention, which is also the same as that described in this membrane (1).

[0113] Furthermore, as described above, the diaphragm is a loudspeaker diaphragm, and more preferably a miniature loudspeaker diaphragm. From the viewpoint of suitability for use as a miniature loudspeaker diaphragm, the size of the diaphragm should preferably be 25 mm or less, more preferably 20 mm or less, and the maximum diameter should be 5 mm or more. Furthermore, the term "maximum diameter" refers to the diameter when the diaphragm is circular, and the major diameter when it is oval or egg-shaped.

[0114] The vibrating plate can be formed solely from this membrane (2) or from a composite material of this membrane (2) and other components. For example, as described above, any part of the edge or body can be formed from other components.

[0115] Furthermore, in order to improve the secondary processing suitability or dust resistance of the diaphragm, or to adjust or enhance its acoustic characteristics, the surface of the diaphragm may be appropriately coated with an antistatic agent, or subjected to metal vapor deposition or sputtering, or colored (black or white, etc.). Furthermore, it may also be appropriately laminated with metals such as aluminum, or composited with non-woven fabrics, etc.

[0116] (Audio Converter) The audio converter of the present invention is an audio converter having the above-mentioned audio components, preferably a vibrating plate. Typical audio converters are electrical audio converters, including: speakers, handsets, microphones, headphones, etc. Among these, the audio converter is preferably a speaker, preferably a miniature speaker such as that found in mobile phones.

[0117] [Third Embodiment of the Invention] The third embodiment of the present invention is a film for an audio component. <Film for Audio Components> The film for an audio component of the present invention (hereinafter also referred to as the film (3)) has the following viscoelastic properties (a). (Viscoelastic Properties) (a) The storage modulus E' at a temperature of 20°C and a frequency of 10 Hz is 0.1 MPa or more and 500 MPa or less. If the storage modulus E' is 0.1 MPa or more, the film has moderate hardness and is easy to peel off from the release film, and there is no risk of breakage during peeling. Furthermore, it can maintain its shape after the release film is peeled off. On the other hand, if the storage modulus E' is 500 MPa or less, the film has moderate softness and can achieve mold conformability or shaping during molding. Based on the above viewpoints, E' is preferably 0.5 MPa to 300 MPa, more preferably 0.8 MPa to 200 MPa, and even more preferably 1.0 MPa to 100 MPa.

[0118] Furthermore, the membrane (3) preferably has the viscoelastic properties of the following (b) to (d) in the hardened state. (b) The storage modulus E'20 at a temperature of 20°C and a frequency of 10 Hz is 0.1 MPa to 500 MPa. (c) The storage modulus E'100 at a temperature of 100°C and a frequency of 10 Hz is 0.1 MPa to 500 MPa. (d) The above E'100 / E'20 is 0.4 to 1.0.

[0119] If the storage modulus E'20 at a temperature of 20°C and a frequency of 10 Hz, as measured in (b), is 0.1 MPa or higher, then the hardened material possesses a certain degree of hardness, and therefore, its operability after hardening is good. On the other hand, if E'20 is 500 MPa or lower, there is a tendency for the sound characteristics of the diaphragm, such as sound quality and playability, to be excellent. From the viewpoint of sound characteristics and operability after hardening, the storage modulus E'20 at 20°C after hardening is preferably 1 MPa or higher and 400 MPa or lower, more preferably 2 MPa or higher and 200 MPa or lower, and even more preferably 4 MPa or higher and 50 MPa or lower.

[0120] Furthermore, if the storage modulus E'100 at a measured temperature of 100°C and a frequency of 10 Hz is 0.1 MPa or more and 500 MPa or less, then the heat resistance is good, and excellent acoustic characteristics are expected even under high-temperature environments. From the viewpoint of acoustic characteristics and operability after curing, the storage modulus E'100 is more preferably 1 MPa or more and 400 MPa or less, more preferably 2 MPa or more and 200 MPa or less, and even more preferably 4 MPa or more and 50 MPa or less.

[0121] Furthermore, by setting the ratio of (d) storage modulus (E'100 / E'20) to within the range of 0.4 to 1.0, there is a tendency for the change in elastic modulus with temperature to be reduced, resulting in good heat resistance. Also, the change in elastic modulus during heating is relatively small; therefore, the sound quality is less likely to deteriorate under high-temperature conditions, and excellent sound reproduction is easily maintained from the low-temperature range to the high-temperature range. From the above perspective, the aforementioned ratio (E'100 / E'20) is preferably 0.5 to 0.99, more preferably 0.55 to 0.97, and even more preferably 0.6 to 0.95.

[0122] This membrane (3) can be a single-layer membrane or a multilayer membrane, provided that it has the viscoelastic properties described in (a) above, and preferably the viscoelastic properties described in (b) to (d) above in the hardened state. The key to satisfying condition (a) above is that the membrane has a certain degree of hardness. In the case of a multilayer membrane, it is advisable that at least one of the multilayers has a certain degree of hardness. If it is a single-layer membrane, it is preferable to have a cross-linked structure that satisfies the degree of cross-linking described in condition (a) above. Considering the flexibility of the membrane, its conformability to the mold during forming, or its shapeability, it is preferable to have a membrane with a moderate degree of cross-linking. That is, in terms of hardness, it is preferable to be a membrane that is harder than an uncross-linked membrane and softer than a fully hardened membrane (low-hardness membrane).

[0123] Furthermore, if it is a multilayer film, one of its layers may be a layer with a cross-linked structure and a high hardness (hereinafter sometimes referred to as a "high hardness layer"). That is, this film (3) preferably has at least one high hardness layer and at least one unhardened layer. Specifically, examples include: a two-layer structure of high hardness layer / unhardened layer, and two three-layer structures of high hardness layer / unhardened layer / high hardness layer and unhardened layer / high hardness layer / unhardened layer. Also, it may be a four-layer structure, for example, with two intermediate layers, and an interlayer may exist between each layer. In this way, in the case of a laminated film, by designing the hardness of a certain layer to be higher, it is easy to obtain a laminated film that satisfies the above condition (a), and it is especially preferred to have a laminated structure of high hardness layer / unhardened layer / high hardness layer. Moreover, here, the so-called unhardened layer not only refers to the case of complete non-crosslinking, but also includes the partially crosslinked form, for example, the above-mentioned low hardness film can also be used as the unhardened layer. Furthermore, the gel fraction of the uncured layer should be lower than that of the highly cured layer.

[0124] (Gel fraction) The gel fraction of this film (3) is preferably 90% or less. If the gel fraction is 90% or less, the film can remain soft before molding and can be sufficiently hardened during molding, thereby obtaining shapeability or mold conformability, and obtaining a degree of moldability suitable for practical use. From the point of view of shapeability and moldability, the gel fraction is preferably 85% or less, more preferably 80% or less. There is no particular limitation on the lower limit of the gel fraction, which is 0% or more, preferably 10% or more, and more preferably 20% or more. If the gel fraction is 10% or more, it is easy to adjust the above condition (a) to the above specific range, and the film (3) is not easily damaged when the release film is peeled off before molding.

[0125] As described above, the film preferably has at least one highly hardened layer and at least one unhardened layer. The unhardened layer preferably has a gel content of 0% or more and less than 80%. If the gel content of the unhardened layer is less than 80%, the film can easily remain soft before molding, and it can be sufficiently hardened during molding. Therefore, the shapeability and mold conformability are sufficient, and the formability is improved. From the viewpoint of shapeability and formability, the gel content of the unhardened layer is preferably 70% or less, more preferably 65% ​​or less, and even more preferably 60% or less. The gel content of the intermediate layer is not particularly limited, and it can be 0% or more, for example, it can be 10% or more, or it can be 20% or more.

[0126] On the other hand, the gel fraction of the high-curing layer is preferably 80% or more. If the gel fraction of the outermost / backmost layer is 80% or more, the membrane (3) is easy to peel off from the release membrane, and there is little risk of damage during peeling. Furthermore, as mentioned above, by increasing the gel fraction of the membrane (3), the shape retention before curing can also be further improved. From the above point of view, the gel fraction of the high-curing layer is preferably 85% or more, and more preferably 90% or more. There is no particular upper limit to the gel fraction of the high-curing layer, it can be 100% or less, generally below 100%, for example, it can be 99% or less.

[0127] This membrane (3), whether it is a single layer or a multilayer, if the gel content of the membrane surface is 75% or more, it can prevent the membrane from being difficult to remove from the metal mold after being clamped between the metal molds for pressurization.

[0128] Furthermore, the gel fraction can be determined based on the following steps: 1) Collect approximately 100 mg of sample from the entire membrane, or from the middle layer, outermost layer, or backmost layer of the membrane, and determine the mass of the sample (a); 2) Immerse the collected sample in chloroform at 23°C for 24 hours; 3) Remove the solids from the chloroform and vacuum dry at 50°C for 7 hours; 4) Determine the mass of the dried solids (b); 5) Using the masses (a) and (b), calculate the gel fraction according to the following formula (i).

[0129] [Number 1]

[0130] According to the above measurement method, the gel fraction is calculated by including not only the cross-linking components contained in the membrane, but also the insoluble components other than the cross-linking components such as fillers. Among them, for the intermediate layer of the membrane (3) before curing, the gel fraction is calculated by the ratio of the gel fraction of the entire membrane (3) before curing and the outermost / backmost layer to the layer thickness.

[0131] This membrane (3) is a curable membrane. As for the type of curing, it can be any type of light curing, moisture curing, or thermocuring, but it is preferably thermocurable. By making this membrane (3) thermocurable, it can be cured while being heated and formed, thus its formability is better. Furthermore, if this membrane (3) is thermocurable, its gel fraction increases by heating.

[0132] This membrane (3) preferably has a cross-linked structure. By having a moderate cross-linked structure, as described above, in the case of a single-layer membrane, it is easy to obtain a membrane that satisfies the above-mentioned viscoelastic property (a). Furthermore, the shape retention before curing (i.e., before forming) is easily improved. Furthermore, in the case of this membrane (3) being a laminated membrane, as described above, by having at least one of the multilayers have a cross-linked structure, it is easy to obtain a membrane that satisfies the above-mentioned viscoelastic property (a). If this is the case, the shape retention before curing is easily improved and the flexibility of the membrane is not significantly impaired.

[0133] The thickness of the membrane (3) is not particularly limited, but it is preferably 5 μm or more and 500 μm or less, more preferably 15 μm or more and 400 μm or less, and even more preferably 30 μm or more and 300 μm or less. If the thickness of the membrane is within this range, a molded product with a suitable thickness for use as a vibrating plate can be manufactured.

[0134] (Elongation at break) The elongation at break of this membrane (3) is preferably 100% or more in the hardened state, more preferably 200% or more, and even more preferably 300% or more. If the elongation at break is within this range, the toughness of the membrane is improved, thereby making it less prone to breakage due to long-term vibration, and it tends to have excellent durability when used in sound components such as diaphragms. Furthermore, the higher the elongation at break, the better, and there is no particular upper limit, usually below 1500%.

[0135] Furthermore, the storage modulus and tensile elongation at break can be determined by the method described in the examples. The storage modulus and tensile elongation at break in the hardened state can be measured by hardening the membrane in a manner that makes the overall gel content of the membrane (3) reach 80% or more. Specific methods for hardening the membrane (3) to a gel content of 80% or more can be listed as follows: heat curing and radiation curing. In the case of heat curing, the heating temperature during curing is preferably 180°C or higher and 260°C or lower, more preferably 190°C or higher and 250°C or lower, and even more preferably 200°C or higher and 240°C or lower. Also, the heating time is preferably 1 second or higher and 5 minutes or lower, more preferably 5 seconds or higher and 4 minutes or lower, even more preferably 10 seconds or higher and 3 minutes or lower, and particularly preferably 20 seconds or higher and 2 minutes or lower. Furthermore, the heating pressure is preferably between 0.01 MPa and 100 MPa, and more preferably between 0.1 MPa and 50 MPa. On the other hand, in the case of radiation curing, the radiation used for radiation crosslinking can be electron beams, X-rays, gamma rays, etc. By adjusting the type of radiation used and the cumulative radiation dose, the membrane (3) can be cured to a gel fraction of 80% or more. Furthermore, the detailed methods for measuring storage modulus and elongation at break are as described in the examples. When the membrane has directionality, it is advisable to measure TD (the direction orthogonal to the resin flow direction).

[0136] This membrane (3) is composed of resin layers, and the resin constituting the resin layers is preferably a curable resin, and more preferably a thermosetting resin. Among them, preferred specific examples include: epoxy resin, urethane resin, polysiloxane resin, acrylic resin, phenolic resin, unsaturated polyester resin, polyimide resin, melamine resin, etc. When this membrane (3) is a multilayer membrane, it is preferable that each layer is a resin layer. Furthermore, the resin in each layer of this membrane (3) can be a single type, or two or more types can be used together. Furthermore, when this membrane (3) is a multilayer membrane, each layer can use the same type of resin, or different types of resin can be used, but it is preferable to use the same type of resin. By using the same type of resin, it is easy to bond the layers together even without using an adhesive layer, etc.

[0137] Furthermore, this membrane (3) is preferably a polysiloxane membrane. Moreover, in the case of a multilayer membrane, the polysiloxane membrane may be a membrane in which polysiloxane resin is used as the resin in some of the multilayer layers, and it is particularly preferred that polysiloxane resin is used in all layers. If this membrane (3) is a polysiloxane membrane, it has good heat resistance, mechanical strength, etc., and it is also easy to meet the above-mentioned viscoelastic properties (a) and (b) to (d). In addition, the elongation at break can also be easily adjusted to the above-mentioned required range.

[0138] (Organic polysiloxane) As the polysiloxane used in this membrane (3), organopolysiloxanes can be listed. Organopolysiloxanes, for example, have the structure represented by the following formula (I). RnSiO(4-n) / 2・・・(I) Here, R is a monovalent hydrocarbon group that may be the same or different, substituted or unsubstituted, preferably a monovalent hydrocarbon group with 1 to 12 carbon atoms, more preferably a monovalent hydrocarbon group with 1 to 8 carbon atoms, and n is a positive number of 1.95 to 2.05.

[0139] As R, examples include: alkyl such as methyl, ethyl, propyl, butyl, hexyl and dodecyl, cycloalkyl such as cyclohexyl, alkenyl such as vinyl, allyl, butenyl and hexenyl, aryl such as phenyl and tolyl, aralkyl such as β-phenylpropyl, and chloromethyl, trifluoropropyl and cyanoethyl, etc., in which one or all of the hydrogen atoms bonded to the carbon atom of such groups are substituted with halogen atoms or cyano groups.

[0140] The organopolysiloxane is preferably end-capped with trimethylsilyl, dimethylvinyl, dimethylhydroxysilyl, or trivinylsilyl groups. Furthermore, the organopolysiloxane preferably has at least two alkenyl groups in its molecule. Specifically, R preferably contains 0.001 mol% to 5 mol%, more preferably 0.005 mol% to 3 mol%, more preferably 0.01 mol% to 1 mol%, and even more preferably 0.02 mol% to 0.5 mol%, and most preferably contains vinyl groups. The organopolysiloxane is essentially a linear organopolysiloxane, and some may have branches. It may also be a mixture of two or more molecules with different molecular structures.

[0141] The organic polysiloxane constituting the resin layer of this membrane (3) is preferably cross-linked by a cross-linking agent, and more preferably by an organic peroxide. Therefore, the resin layer is preferably a cured product formed by curing a resin composition containing an organic polysiloxane and an organic peroxide as a cross-linking agent. At this time, the resin layer should be cured to the extent that the gel fraction is within the range required above. In the case of the monolayer membrane, it is preferable to have a moderate cross-linking structure and moderate hardness. It is preferable to be in a semi-cured state so that the gel fraction is within the range required above. Therefore, the organic peroxide formulated in the resin layer constituting the monolayer membrane should be partially decomposed and partially contained in the resin layer in the state of organic peroxide without decomposition.

[0142] On the other hand, when the membrane (3) is a multilayer membrane, it is preferable to have at least a highly hardened layer and an unhardened layer. The highly hardened layer is preferably an organopolysiloxane crosslinked by an organic peroxide, which decomposes and is almost no longer present. On the other hand, the unhardened layer is preferably a resin composition containing a crosslinking agent such as an organopolysiloxane and an organic peroxide, and is in an unhardened state, or even if hardened, in a semi-hardened state, so that the gel fraction is within the aforementioned desired range. The organic peroxide formulated in the unhardened layer should be almost undecomposed and remain in the unhardened layer in the state of organic peroxide.

[0143] Furthermore, in the case of this membrane (3) being, for example, two types of three-layer laminated membranes, there are two configurations: the surface layer and the back layer are highly hardened layers and the middle layer is an unhardened layer; and there are two configurations: the surface layer and the back layer are unhardened layers and the middle layer is a highly hardened layer. Regardless of the layer composition, the organic polysiloxane in the unhardened layer is in an uncrosslinked state, or even if it is crosslinked, it is in a partially crosslinked state (semi-hardened state), and the organic peroxide is almost not decomposed and remains in the unhardened layer. On the other hand, the organic polysiloxane in the highly hardened layer is preferably crosslinked by organic peroxide, and the organic peroxide decomposes and is almost no longer present.

[0144] As an organic peroxide, examples include: alkyl peroxides such as ditert-tert-butyl peroxide, 2,5-dimethyl-2,5-di(tert-butylperoxy)hexane, and 2,5-dimethyl-2,5-bis(tert-butylperoxy)hexane, and aralkyl peroxides such as 2,4-diisopropylphenyl peroxide. From the viewpoint of crosslinking speed or safety, alkyl peroxides are preferred, especially 2,5-dimethyl-2,5-di(tert-butylperoxy)hexane.

[0145] The amount of organic peroxide in the resin composition forming the resin layer is preferably 0.01% by mass to 10% by mass, more preferably 0.03% by mass to 5% by mass, further preferably 0.05% by mass to 4% by mass, particularly preferably 0.1% by mass to 3% by mass, and even more preferably 0.3% by mass to 2% by mass. If the amount of organic peroxide is within this range, there is a tendency to safely obtain a composition with a sufficient curing speed. Furthermore, the organic peroxide formulated in the resin composition is substantially decomposed and almost no longer present in the highly cured layer, but preferably present in the uncured layer at an amount within the above-mentioned formulation range.

[0146] The resin composition is preferably a composable type containing an organopolysiloxane. The composable resin composition is non-liquid (e.g., solid or paste) without self-flowing in the uncured state at room temperature (25°C), but can be uniformly mixed using a mixer described later. By using a composable resin composition in this film (3), the productivity of processing the resin composition into an intermediate layer or the outermost / backmost layer is good in the case of a laminated film.

[0147] Furthermore, as described above, the resin composition forming the resin layer may also use a resin other than polysiloxane (organopolysiloxane) as the resin. In this case, the outermost / backmost layer should also be a layer formed by curing, for example, a resin composition containing resin and crosslinking agent in such a way that the gel fraction is within the desired range. Furthermore, the intermediate layer should preferably be formed from a resin composition similarly containing resin and crosslinking agent, but in this case, the resin composition should preferably be in an uncured state, or even if cured, in a semi-cured state, so that the gel fraction is within the aforementioned desired range.

[0148] The resin layer constituting this membrane (3) may also contain fillers such as silicon oxide fillers. By including fillers in this membrane (3), it is easy to set the mechanical properties of the membrane, such as storage modulus or elongation at break, within a suitable range. Furthermore, by using fillers, it is easy to adjust the viscosity or hardness of the resin composition, and the flowability or secondary processing properties of the resin composition are also easily optimized. Moreover, it has the advantage of being able to adjust the hardness appropriately according to the design of the acoustic component or the acoustic characteristics. Furthermore, the filler constitutes part of the gel component when the gel fraction is measured, and the gel fraction of each layer is increased due to the presence of fillers. Even if the gel fraction is increased due to the presence of fillers, the hardness of each layer can be increased in the same way as when the gel fraction is increased by crosslinking.

[0149] Examples of silica-based fillers include fuming silica or precipitated silica, as well as silica-based fillers surface-treated with silane coupling agents. The filler content in each layer is based on the total amount of the resin composition constituting each layer, and is, for example, 10% by mass to 50% by mass, preferably 15% by mass to 40% by mass, and more preferably 20% by mass to 35% by mass. Furthermore, the average particle size of the filler is, for example, 0.01 μm to 20 μm, preferably 0.1 μm to 10 μm, and more preferably 0.5 μm to 5 μm. The average particle size of the filler can be measured using a particle size distribution measuring device based on laser diffraction, etc., as the median particle size (D50).

[0150] In this invention, the resin composition used to form the resin layer may contain various additives such as heat stabilizers, antioxidants, ultraviolet absorbers, light stabilizers, antibacterial and antifungal agents, antistatic agents, lubricants, pigments, dyes, flame retardants, and impact modifiers within the range of non-destructive effects.

[0151] When the film (3) is a laminated film, the resin compositions used to form each layer may have the same composition or different compositions. Furthermore, the composition of the resin composition referred to here means the composition of the resin composition before curing.

[0152] In this invention, commercially available products can also be used as organopolysiloxanes. Furthermore, commercially available products containing mixtures of additives such as silicon oxide fillers in addition to organopolysiloxanes can also be used. Specifically, products manufactured by Shin-Etsu Chemical Industry Co., Ltd. under the trade names "KE-597-U" and "KE-594-U" can also be used.

[0153] [Membrane with release film attached] The above-mentioned membrane (3) may also be used as a membrane with release film attached. The membrane with release film attached has the above-mentioned membrane (3) and a release film disposed on at least one side of the membrane (3). Furthermore, in the membrane with release film attached, it is preferable to have release films disposed on both sides of the membrane (3).

[0154] The release film can be a resin film, or a resin film having a release layer formed by at least one side being treated with a release layer. When the release film has a release layer, it is preferable to deposit the release film onto the film (3) in such a way that the release layer contacts the film (3). Examples of resins used as resin films include: polyolefin resins such as polypropylene, acrylic resins, polystyrene resins, polyacetal resins, polyamide resins, polyester resins, polycarbonate resins, ABS resins, polyetheretherketone resins, etc. Among these, polyester resins are preferred, and polyethylene terephthalate resins are preferred. The thickness of the release film is not particularly limited, but is preferably 5 μm or more and 100 μm or less, more preferably 7 μm or more and 80 μm or less, and even more preferably 10 μm or more and 50 μm or less.

[0155] This film (3) is protected by a release film. Therefore, damage to this film (3) is prevented during transportation, etc. Furthermore, the release film can be the release film deposited during the manufacture of this film (3), or a release film can be deposited on the manufactured film (3). Also, this film (3) can be shaped by, for example, shaping as described below, but during shaping, it is advisable to peel the release film from this film (3) and place it in a mold such as a metal mold. At this time, this film (3) can be peeled off from the release film without damage.

[0156] [Manufacturing Method of the Film (3)] The film (3) can be formed by a general molding method, such as extrusion molding. In the case of a single-layer film, a resin composition for forming a single-layer film is obtained by mixing, etc., and the resin composition is formed by extrusion molding, etc. Alternatively, a release film can be used, and the resin composition is laminated between the release films to obtain the film (3) with the release film attached. In the case of a single-layer film, it is preferable to be semi-cured to satisfy the condition (a) of viscoelastic properties. As for the semi-curing condition, there is no particular limitation as long as the above condition (a) is satisfied. In the case of the film (3) being a laminated film, it can be formed by lamination molding, co-extrusion molding, coating, or a combination thereof. Among these, considering the ease of multilayering of the outermost / backmost layer and the intermediate layer, lamination molding is preferred. As described above, the preferred method for manufacturing this membrane (3) includes a step of curing at least a portion of one or more resin layers used to form the membrane.

[0157] Furthermore, in the case of multiple layers, it is preferable to include a step of laminating a cured resin layer with a resin layer having curable properties. In the case of using lamination molding, it is preferable to first prepare an outermost layer and an outermost back layer, and then laminate an intermediate layer between these outermost and backmost layers. More specifically, it is preferable to first prepare a resin composition for obtaining the outermost and backmost layers (resin composition for the outermost or backmost layer), and a resin composition for obtaining the intermediate layer (resin composition for the intermediate layer).

[0158] There are no particular limitations on the resin compositions; for example, they can be obtained by mixing the materials constituting the resin composition. The mixing machine used for mixing can be a known mixing machine such as a single-shaft or twin-shaft extruder, a two-roll or three-roll calender, a roller mill, a plastomill, a Bamboo mixer, a kneader, or a planetary mixer. The mixing temperature is adjusted appropriately according to the type or mixing ratio of the resin, and the presence or type of additives. To inhibit cross-linking (hardening) and moderately reduce the resin viscosity for easy mixing, a temperature of 20°C to 150°C is preferred, more preferably 30°C to 140°C, further preferably 40°C to 130°C, particularly preferably 50°C to 120°C, and especially preferably 60°C to 110°C. The mixing time is sufficient to achieve a uniform mixing of the materials constituting the resin composition, for example, from a few minutes to a few hours, preferably from 5 minutes to 1 hour.

[0159] Hereinafter, a method for manufacturing two types of three-layer films—a highly hardened layer, an unhardened layer, and a highly hardened layer—will be described. A laminated body is obtained by depositing the resin composition of the outermost or backmost layer prepared as described above onto a release film using a conventional method. Subsequently, the laminated body is heated or otherwise hardened to obtain the resin composition. This yields a laminated body formed by depositing the outermost or backmost layer onto a release film. Furthermore, when the laminated body has a release treatment surface, it is preferable to deposit the resin composition of the outermost / backmost layer onto the release treatment surface of the release film.

[0160] Next, the film (3) is obtained by laminating an intermediate layer formed of an intermediate layer resin composition between the above-mentioned laminated films by lamination. Specifically, the intermediate layer resin composition is fed into the laminated films in an uncured or semi-cured state between two laminated films, for example, between a pair of rollers, from two directions. Here, the intermediate layer resin composition is preferably fed into the laminated films by extrusion from a T-die or the like using an extruder. Furthermore, each laminated film is preferably fed out sequentially with the outermost and backmost layers facing each other. Then, the thickness is adjusted as needed by the gap between the rollers to obtain a laminated body with an uncured or semi-cured intermediate layer formed between the laminated films. This laminated body is preferably a laminated structure of release film / outermost layer / intermediate layer / backmost layer / laminated film to become the above-mentioned film with release film attached.

[0161] On the other hand, in the case of an uncured layer / highly cured layer / uncured layer, firstly, a monolayer film is obtained in advance by extrusion molding or the like, and then crosslinked and cured to prepare a monolayer film for a highly cured layer. Secondly, a resin composition for an uncured layer is coated on both sides of the highly cured layer, thereby manufacturing a film of this type.

[0162] [Molded Article] This film (3) can be molded into a molded article by forming and hardening it using a mold such as a metal mold. Typically, it is advisable to use a mold to shape it into various molded articles. It is advisable to harden it according to the characteristics of this film (3), preferably by heating, light irradiation, moisture application or a combination of these treatments, preferably by heating. This film (3) is a film for a vibrating plate, and the molded article constitutes a vibrating plate. When obtaining a molded article from this film (3), it is advisable to perform at least the following steps 1 and 2. Step 1: Heating this film (3), forming it using a mold, and hardening this film (3) Step 2: Peeling the formed and hardened film (3) (i.e., the molded article) from the mold.

[0163] The following is a more detailed explanation of each step. (Step 1) In step 1, the film (3) is heated, shaped using a mold, and the film (3) is hardened to form a molded article. The molded article is preferably shaped using a mold to form the desired shape. There are no particular limitations on the forming in step 1, and it is advisable to use any forming method such as vacuum forming, air forming, or pressure forming. Among these, pressure forming is preferred in terms of the ease of forming.

[0164] As a mold, a corresponding mold can be prepared according to the molding method. It is advisable to set the mold with concave and convex shapes that correspond to the shape of the molded article being manufactured. Typically, a metal mold (metal mold) is used as the mold, but a resin mold can also be used. For example, as described below, if the molded article (vibrating plate) has at least one part that is domed or conical, it is advisable to set the mold with concave and convex shapes that correspond to the domed or conical shape. Also, when the surface of the molded article (vibrating plate) has tangential edges, it is advisable to set the mold with concave and convex shapes that correspond to the tangential edges.

[0165] As mentioned above, this film (3) is sometimes attached with a release film. As mentioned above, this film (1) is preferably placed in the mold after the release film is peeled off.

[0166] In step 1, the heated film (3) can be shaped using a mold. For example, the film (3) placed on the mold can be shaped by heating while the mold is in place, or the preheated film (3) can be placed on the mold and then shaped by the mold. These methods can also be combined. Furthermore, the film (3) can be heated by any method. For example, when heating the film placed on the mold, the mold can be heated and the heat can be conducted, or other methods can be used for heating.

[0167] The heating temperature during shaping or hardening is preferably 180°C to 260°C, more preferably 190°C to 250°C, and even more preferably 200°C to 240°C. If the temperature during shaping or hardening is within this range, there is a tendency for the film (3) to harden at a sufficient rate without deforming due to thermal melting.

[0168] The forming time is preferably 1 second to 5 minutes, more preferably 5 seconds to 4 minutes, further preferably 10 seconds to 3 minutes, and even more preferably 20 seconds to 2 minutes. If the heat treatment time during forming is within this range, there is a tendency for sufficient hardening while maintaining productivity. Furthermore, the film (3) is preferably formed and hardened at the same time, but there is no particular limitation, and it may also be hardened after forming. Furthermore, the forming time refers to the time from forming to hardening of the film (3) in the mold, excluding the mold movement time before forming begins and after forming ends, or the time when demolding the laminate.

[0169] (Step 2) In step 2, the film (3) formed and hardened in step 1 is peeled off from the mold to obtain a molded article. In this invention, since the gel fraction of the film (3) does not reach a certain value, its shapeability is high, and the film's conformity to the mold is high. Therefore, the molded article can be manufactured with high forming accuracy. Furthermore, since the film (3) has specific viscoelastic properties, its shape retention is high and its operability is good. Moreover, it can be peeled off without damage when peeling off the release film, maintaining the film shape and easily placed in the metal mold. In addition, by not depositing the release film, the step of peeling the release film off the molded article can be omitted, thus making mass production easy.

[0170] In this invention, the gel fraction of the molded article obtained from the above-described film is preferably 80% or more. If the gel fraction is 80% or more, it is easy to obtain a molded article with a storage modulus and mechanical strength suitable for acoustic components. The gel fraction of the molded article is more preferably 85% or more, and even more preferably 90% or more. Furthermore, there is no particular limitation on the upper limit of the gel fraction of the molded article; it can be 100% or less, generally below 100%, for example, 99% or less. Moreover, the gel fraction of the molded article refers to the gel fraction of the entire molded article, and it is advisable to take samples equally along the thickness direction of the molded article for measurement. The detailed method for measuring the gel fraction is as described above.

[0171] [Uses of the membrane] As described above, the membrane of the present invention is preferably used in audio components. The audio component of the present invention is formed by hardening the membrane (3), and more specifically, it preferably includes the above-described molded article. The audio component is more preferably a diaphragm, specifically a speaker diaphragm, and is particularly preferably used as a miniature speaker diaphragm for mobile phones, etc.

[0172] By properly shaping this membrane (3), it can become various acoustic components such as diaphragms. The acoustic component preferably has, for example, at least a portion of it having a dome or cone shape. Furthermore, the acoustic component may have tangent edges on its surface. When it has a dome or cone shape, or has tangent edges, the acoustic component is preferably used as a diaphragm, and more preferably as a loudspeaker diaphragm.

[0173] (Vibrating Plate) To provide a more detailed description of the vibrating plate, there are no particular limitations on its shape; it can be any shape, such as circular, oval, or egg-shaped. Furthermore, a vibrating plate generally has a main body that vibrates in response to electrical signals, etc., and an edge surrounding the main body. The main body of the vibrating plate is usually supported by the edge. As described above, the shape of the vibrating plate can be domed, conical, or a combination of these shapes, or other shapes used for vibrating plates.

[0174] At least a part of the acoustic component can be formed by this membrane (3). For example, the main body of the diaphragm can be formed by this membrane (3) and the edge of the diaphragm can be formed by other components; or the edge can be formed by this membrane (3) and the main body can be formed by other components. Of course, the main body and the edge can also be integrally formed by this membrane (3), or the entire diaphragm can be formed by this membrane (3).

[0175] FIG1 is a diagram showing the structure of the vibrating plate 1 according to one embodiment of the present invention, which is the same as that described in this membrane (1). FIG2 is a diagram showing the structure of the vibrating plate 11 according to another embodiment of the present invention, which is the same as that described in this membrane (1). FIG3 is a top view of the vibrating plate 21 according to another embodiment of the present invention, which is also the same as that described in this membrane (1).

[0176] Furthermore, as described above, the diaphragm is a loudspeaker diaphragm, and more preferably a miniature loudspeaker diaphragm. From the viewpoint of suitability for use as a miniature loudspeaker diaphragm, the size of the diaphragm should preferably be 25 mm or less, more preferably 20 mm or less, and the maximum diameter should be 5 mm or more. Furthermore, the term "maximum diameter" refers to the diameter when the diaphragm is circular, and the major diameter when it is oval or egg-shaped.

[0177] The vibrating plate can be formed solely from this membrane (3) or from a composite material of this membrane (3) and other components. For example, as described above, any part of the edge or body can be formed from other components.

[0178] Furthermore, in order to improve the secondary processing suitability or dust resistance of the diaphragm, or to adjust the acoustic characteristics or enhance the design, the surface of the diaphragm may be appropriately coated with an antistatic agent, or subjected to metal vapor deposition or sputtering, or colored (black or white, etc.). Furthermore, it may also be appropriately laminated with metals such as aluminum, or composited with non-woven fabrics, etc.

[0179] (Audio Converter) The audio converter of the present invention is an audio converter having the above-described audio components, preferably a vibrating plate. Typical audio converters are electrical audio converters, including: speakers, handsets, microphones, headphones, etc. Among these, the audio converter is preferably a speaker, preferably a miniature speaker such as that found in mobile phones.

[0180] [Fourth Embodiment of the Invention] The fourth embodiment of the present invention is a film. <Film> The film of the present invention (hereinafter also referred to as the film (4)) comprises an outermost / backmost layer (outermost surface layer and outermost backmost layer) with a static friction coefficient of 3 or less, and at least one hardening intermediate layer disposed between the outermost / backmost layer. By making the outermost / backmost layer relatively hard and reducing the static friction coefficient of the outermost / backmost layer, the film (4) can prevent adhesion to the mold during molding. Furthermore, by using a hardening intermediate layer, the film is ensured to have a certain degree of softness before molding and can be sufficiently hardened during molding, thus exhibiting good shapeability and good mold conformability. Moreover, although the intermediate layer is hardening and the film as a whole is relatively soft, by providing relatively hard outermost / backmost layers on both surfaces, the film is appropriately kept soft by utilizing the outermost / backmost layers, thereby maintaining good shape retention before molding even without laminating release films or the like with the film (4), and exhibiting good operability. Therefore, even without the addition of a release film, this film (4) can be easily placed in the mold for forming, thus eliminating the need for peeling off the release film after forming.

[0181] (Static Friction Coefficient) As described above, the static friction coefficient of the outermost / backmost layer of this film (4) is 3 or less. If the static friction coefficient is higher than 3, the film (4) is prone to sticking to the mold, making it difficult to achieve good formability. The static friction coefficient of the outermost / backmost layer is preferably 2.5 or less, more preferably 2 or less, and even more preferably 1.5 or less. As described above, reducing the static friction coefficient of the outermost / backmost layer can further suppress adhesion to the mold. There is no particular limitation on the lower limit of the static friction coefficient of the outermost / backmost layer of this film (4), for example, it can be 0.3 or more, or 0.5 or more, or 0.7 or more. Furthermore, the static friction coefficients of the outermost / backmost layer (i.e., the outermost surface layer and the outermost backmost layer) can be the same or different.

[0182] The static friction coefficient can be appropriately adjusted by the forming method of the outermost / backmost layer, the material of the outermost / backmost layer, and the gel content of the outermost / backmost layer. For example, if the gel content of the outermost / backmost layer is increased, the outermost / backmost layer tends to harden, and the static friction coefficient tends to decrease. More specifically, by setting the gel content of the outermost / backmost layer to 80% or more, it is easy to make the static friction coefficient 3 or less. Furthermore, by using specific resins such as polysiloxane resin or inorganic particles in the resin constituting the outermost / backmost layer, the static friction coefficient can also be reduced. Moreover, the static friction coefficient can be adjusted by appropriately adjusting the surface shape of the outermost / backmost layer; for example, by imparting roughness to the outermost / backmost layer, the static friction coefficient can also be reduced. Furthermore, the static friction coefficient is for stainless steel plates and can be measured by a sliding test based on JIS K7125 (1999).

[0183] (Gel content) The gel content of this membrane (4) is preferably 0% to 90%. If the gel content is 90% or less, the membrane can be kept soft before molding, and it can be fully hardened during molding. Therefore, the shapeability or mold conformability is sufficient, and the formability is improved. From the point of view of shapeability and formability, the gel content of this membrane (4) is preferably 80% or less, more preferably 75% or less, and even more preferably 70% or less. The gel content of this membrane (4) is not particularly limited, and it can be 0% or more, for example, 10% or more, or 20% or more. Furthermore, the gel content of this membrane (4) is a value obtained by measuring the gel content of the entire membrane.

[0184] As described above, at least one hardening intermediate layer is provided between the outermost and back layers. The gel content of the hardening intermediate layer is preferably 0% or more and less than 80%. If the intermediate layer has a gel content of less than 80%, the film before molding is easily kept soft, and it can be sufficiently hardened during molding. Therefore, the shapeability and mold conformability are sufficient, and the formability is improved. From the viewpoint of shapeability and formability, the gel content of the intermediate layer is preferably 70% or less, more preferably 65% ​​or less, and even more preferably 60% or less. The gel content of the intermediate layer is not particularly limited; it can be 0% or more, for example, 10% or more, or 20% or more.

[0185] The aforementioned curing intermediate layer may comprise one layer or two or more layers, but preferably one layer. Therefore, the membrane (4) preferably has a three-layer structure of an outermost layer / intermediate layer / backmost layer, and may also have a four-layer structure of an outermost layer / intermediate layer / intermediate layer / backmost layer with two or more intermediate layers between the outermost and backmost layers. Furthermore, the membrane (4) may also have layers other than the aforementioned curing intermediate layer between the outermost layer and the backmost layer. For example, other layers such as adhesive layers for improving the adhesion between these layers may be provided between the intermediate layer and the outermost layer, or between the intermediate layer and the backmost layer. Furthermore, other layers such as adhesive layers may also be provided between intermediate layers.

[0186] In this film (4), the gel fraction of the outermost / backmost layer (i.e., the outermost surface layer and the outermost backmost layer) is preferably 80% or more. If the gel fraction of the outermost / backmost layer is 80% or more, the static friction coefficient mentioned above is easily reduced, and the situation of sticking to the mold is less likely to occur during molding. Also, as mentioned above, by increasing the gel fraction of this film (4), the outermost / backmost layer can also be relatively hard before the film hardens, and the shape retention before molding can be further improved. From the above point of view, the gel fraction of the outermost / backmost layer is preferably 85% or more, and more preferably 90% or more. There is no particular limit to the upper limit of the gel fraction of the outermost / backmost layer, it can be 100% or less, generally below 100%, for example, it can be 99% or less. Furthermore, the gel fraction of the outermost / backmost layer (i.e., the outermost surface layer and the outermost backmost layer) can be the same or different.

[0187] Furthermore, the gel fraction can be determined based on the following steps: 1) Collect approximately 100 mg of sample from the entire membrane, or from the outermost or backmost layer of the membrane, and determine the mass of the sample (a); 2) Immerse the collected sample in chloroform at 23°C for 24 hours; 3) Remove the solids from the chloroform and vacuum dry at 50°C for 7 hours; 4) Determine the mass of the dried solids (b); 5) Using the masses (a) and (b), calculate the gel fraction according to the following formula (i).

[0188] [Number 2]

[0189] According to the above measurement method, the gel fraction is calculated by including not only the cross-linking components contained in the membrane, but also the insoluble components other than the cross-linking components such as fillers. Among them, for the intermediate layer of the membrane (4) before curing, the gel fraction is calculated by the ratio of the gel fraction of the entire membrane (4) before curing and the outermost / backmost layer to the layer thickness.

[0190] (Viscoelastic Properties) The film (4) preferably has the viscoelastic properties described in (a) below. (a) The storage modulus E' at a measurement temperature of 20°C is 0.1 MPa or more and 500 MPa or less. If the storage modulus E' is 0.1 MPa or more, the film (4) as a whole has a certain degree of hardness, thereby making it easy to peel off from the release film with little risk of breakage during peeling. Furthermore, even without a release film, it is easy to improve shape retention. On the other hand, by setting the storage modulus E' of the film (4) to 500 MPa or less, a certain degree of flexibility can be ensured, thereby achieving good mold conformability or shaping properties during molding. From these points of view, the storage modulus E' of the film (4) is preferably 0.5 MPa or more, more preferably 0.8 MPa or more, and more preferably 1.0 MPa or more. Furthermore, it is preferable to use an amplitude of 300 MPa or less, even more preferable to use an amplitude of 200 MPa or less, even more preferable to use an amplitude of 100 MPa or less, and most preferably to use an amplitude of 50 MPa or less.

[0191] The membrane (4) preferably has the viscoelastic properties described in (b) below in its cured state, and also preferably has the viscoelastic properties described in (c) below. (b) The storage modulus E'20 at a measured temperature of 20°C is 0.1 MPa or more. (c) The storage modulus E'20 at a measured temperature of 20°C is 0.1 MPa or more and 500 MPa or less. By making the storage modulus E'20 of the membrane (4) 0.1 MPa or more, it has a certain hardness after curing, and therefore has good operability after curing. Furthermore, by making the membrane (4) have the viscoelastic properties described in (c) above, when used in audio components such as diaphragms, it tends to have excellent sound quality and playback performance. From the viewpoint of sound characteristics and operability after curing, the storage modulus E'20 at 20°C after curing is preferably 1 MPa or more, more preferably 2 MPa or more, more preferably 4 MPa or more, and even more preferably 400 MPa or less, more preferably 300 MPa or less, more preferably 200 MPa or less, particularly preferably 100 MPa or less, and most preferably 50 MPa or less.

[0192] The membrane (4) preferably has the following viscoelastic properties (d) in its cured state. (d) The storage modulus E'100 at a measurement temperature of 100°C is 0.1 MPa or more and 500 MPa or less. By ensuring that the storage modulus E'100 of the membrane (4) is within the above range after curing, it exhibits good heat resistance and is expected to obtain excellent acoustic properties even in high-temperature environments. The storage modulus E'100 is more preferably 1 MPa or more, more preferably 1.5 MPa or more, more preferably 2.5 MPa or more, and more preferably 400 MPa or less, more preferably 300 MPa or less, more preferably 200 MPa or less, particularly preferably 100 MPa or less, and most preferably 50 MPa or less.

[0193] Furthermore, the membrane (4) preferably has the viscoelastic properties described below (e) in its hardened state. (e) The ratio of the storage modulus E'100 to the storage modulus E'20 (E'100 / E'20) is 0.4 or more and 1.0 or less. By setting the ratio of the storage modulus (E'100 / E'20) within the above range, there is a tendency for the change in elastic modulus with temperature to be reduced, resulting in good heat resistance. Moreover, the change in elastic modulus during heating is small, therefore, the sound quality is not easily degraded under high temperature conditions, and it is easy to maintain excellent sound playback performance from the low temperature range to the high temperature range. The ratio (E'100 / E'20) is more preferably 0.5 or more, more preferably 0.6 or more, and more preferably 0.65 or more. Furthermore, it is more preferably 0.99 or less, more preferably 0.97 or less, more preferably 0.95 or less, and especially preferably 0.93 or less.

[0194] (Elongation at break) The elongation at break of this membrane (4) is preferably 100% or more in the hardened state, more preferably 200% or more, and even more preferably 300% or more. If the elongation at break is within this range, the toughness of the membrane is improved, thereby making it less prone to breakage due to long-term vibration, and it tends to have excellent durability when used in acoustic components such as diaphragms. Furthermore, the higher the elongation at break, the better, and there is no particular upper limit, usually below 1500%.

[0195] Furthermore, the storage modulus and tensile elongation at break can be determined by the method described in the examples. The storage modulus and tensile elongation at break in the hardened state can be measured by hardening the membrane in a manner that makes the overall gel content of the membrane (4) reach 80% or more. Specific methods for hardening the membrane (4) to a gel content of 80% or more can be listed as follows: heat curing and radiation curing. In the case of heat curing, the heating temperature during curing is preferably 180°C or higher and 260°C or lower, more preferably 190°C or higher and 250°C or lower, and even more preferably 200°C or higher and 240°C or lower. Also, the heating time is preferably 1 second or higher and 5 minutes or lower, more preferably 5 seconds or higher and 4 minutes or lower, even more preferably 10 seconds or higher and 3 minutes or lower, and particularly preferably 20 seconds or higher and 2 minutes or lower. Furthermore, the heating pressure is preferably between 0.01 MPa and 100 MPa, and more preferably between 0.1 MPa and 50 MPa. On the other hand, in the case of radiation curing, the radiation used for radiation crosslinking can be electron beams, X-rays, gamma rays, etc. By adjusting the type of radiation used and the cumulative radiation dose, the membrane (4) can be cured to a gel fraction of 80% or more. Furthermore, the detailed methods for measuring the storage modulus and tensile elongation at break are as described in the examples. In the case where the membrane has directionality, it is advisable to measure TD (the direction orthogonal to the resin flow direction MD).

[0196] As described above, the film (4) is curable by at least making the intermediate layer curable. The film (4) can be photocurable, moisture-curable, or thermocurable, but is preferably thermocurable. By making the film (4) thermocurable, it can be cured while being heated and formed, thus its formability is better. Furthermore, if the film (4) is thermocurable, its gel fraction increases by heating. Also, at least the intermediate layer of the film (4) needs to be thermocurable, and the outermost / backmost layers may also be appropriately thermocurable.

[0197] This membrane (4) preferably has a cross-linked structure. By giving this membrane (4) a cross-linked structure, the shape retention before curing (i.e., before forming) is easily improved. Furthermore, this membrane (4) preferably has a cross-linked structure at least in the outermost / backmost layer. By giving the outermost / backmost layer a cross-linked structure, the shape retention before curing is easily improved without significantly damaging the flexibility of the membrane. Furthermore, by giving the outermost / backmost layer a cross-linked structure, the gel fraction of the outermost / backmost layer can be easily adjusted to the aforementioned desired range.

[0198] The thickness of this membrane (4) is not particularly limited, but it is preferably 5 μm to 500 μm, more preferably 15 μm to 400 μm, and even more preferably 30 μm to 300 μm. If the thickness of the membrane is within this range, it can be manufactured as a molded product with a suitable thickness for use as an acoustic component, especially a diaphragm.

[0199] The thickness of the intermediate layer is not particularly limited, but is preferably 3 μm to 300 μm, more preferably 5 μm to 200 μm, and even more preferably 20 μm to 150 μm. By setting the thickness of the intermediate layer to the lower limit value or above, an uncured portion with a certain thickness and high flexibility is provided in the film (4), thereby improving the formability and making it easier to follow the mold during molding. Furthermore, by setting it to the upper limit value or below, the portion with higher flexibility is prevented from exceeding the necessary thickness, which easily improves the shape retention before molding. Moreover, the thickness of the intermediate layer, when there are two or more intermediate layers, refers to their total thickness.

[0200] Furthermore, the ratio of the thickness of the intermediate layer to the thickness of the overall film (intermediate layer / overall film) is preferably 4 / 10 or more, more preferably 5 / 10 or more, and even more preferably 6 / 10 or more. By setting the thickness ratio (intermediate layer / overall film) to the lower limit value mentioned above, a certain proportion of more flexible portions are provided in the film, thus easily improving formability and mold following during molding. Furthermore, the thickness ratio (intermediate layer / overall film) is preferably 9.9 / 10 or less, more preferably 9.8 / 10 or less, and even more preferably 9.7 / 10 or less. By setting the thickness ratio (intermediate layer / overall film) to the upper limit value mentioned above, it is easy to make the outermost / backmost layers have a certain thickness.

[0201] The thickness of the outermost / backside layer is not particularly limited, but it is preferably 1 μm to 100 μm, more preferably 1 μm to 60 μm, and even more preferably 1 μm to 30 μm. By setting the thickness of the outermost / backside layer to the lower limit value or above, good shape retention before molding can be achieved, and adhesion to the mold can be easily prevented. Furthermore, by setting it to the upper limit value or below, the thickness of the portion with a certain hardness is prevented from exceeding the necessary limit, which can easily improve the formability and mold following ability during molding.

[0202] The thickness of each of the outermost and backmost layers should be less than the thickness of the intermediate layers. The ratio of the thickness of each of the outermost and backmost layers to the thickness of the intermediate layers (outermost layer or backmost layer / intermediate layer) is preferably 1 / 50 or more and less than 1. If the thickness of each of the outermost and backmost layers is less than the thickness of the intermediate layers, the film contains a portion with higher flexibility at a certain thickness ratio, thus easily improving shapeability and mold conformability during molding. Furthermore, if the ratio (outermost layer or backmost layer / intermediate layer) is set to the lower limit value mentioned above or above, the shape retention before molding is improved, and adhesion to the mold is easily prevented. From these points of view, the ratio (outermost layer or backmost layer / intermediate layer) is more preferably 1 / 50 or more and 3 / 5 or less, and more preferably 1 / 50 or more and 2 / 5 or less.

[0203] The intermediate layer and the outermost / backmost layer of this membrane (4) are resin layers, and the resin constituting each resin layer is preferably a curable resin, and more preferably a thermosetting resin. Among them, preferred specific examples include: epoxy resin, urethane resin, polysiloxane resin, acrylic resin, phenolic resin, unsaturated polyester resin, polyimide resin, melamine resin, etc. Each layer of this membrane (4) may use only one of these resins, but it is preferable to use two or more in combination. Furthermore, in this membrane (4), each layer (intermediate layer, outermost layer, and backmost layer) may use the same type of resin or different types of resin, but it is preferable that the intermediate layer and the outermost / backmost layer use the same type of resin. That is, for example, when polysiloxane resin is used in the intermediate layer, it is advisable to also use polysiloxane resin in the outermost / backmost layer. By using the same type of resin, it is easy to bond the layers together (e.g., the middle layer and the outermost layer, the middle layer and the backmost layer) even without using an adhesive layer.

[0204] Furthermore, this membrane (4) is preferably a polysiloxane membrane. Moreover, a polysiloxane membrane refers to a membrane in which one of the intermediate layer, the outermost layer, and the backmost layer uses polysiloxane resin as the resin, and preferably, all three layers (intermediate layer, outermost layer, and backmost layer) use polysiloxane resin. If this membrane (4) is a polysiloxane membrane, it has good heat resistance, mechanical strength, etc., and easily meets the aforementioned viscoelastic properties (a) to (e). Furthermore, the tensile elongation at break or the coefficient of static friction can also be easily adjusted to the aforementioned required range.

[0205] (Organic Polysiloxane) Examples of polysiloxanes used as intermediate layers and outermost / backmost layers include organopolysiloxanes. Organopolysiloxanes, for example, have a structure represented by the following formula (I): RnSiO(4-n) / 2・・・(I) Here, R is a monovalent hydrocarbon group that may be the same or different, substituted or unsubstituted, preferably a monovalent hydrocarbon group with 1 to 12 carbon atoms, more preferably a monovalent hydrocarbon group with 1 to 8 carbon atoms, and n is a positive number from 1.95 to 2.05.

[0206] As R, examples include: alkyl such as methyl, ethyl, propyl, butyl, hexyl and dodecyl, cycloalkyl such as cyclohexyl, alkenyl such as vinyl, allyl, butenyl and hexenyl, aryl such as phenyl and tolyl, aralkyl such as β-phenylpropyl, and chloromethyl, trifluoropropyl and cyanoethyl, etc., in which one or all of the hydrogen atoms bonded to the carbon atom of such groups are substituted with halogen atoms or cyano groups.

[0207] The organopolysiloxane is preferably end-capped with trimethylsilyl, dimethylvinyl, dimethylhydroxysilyl, or trivinylsilyl groups. Furthermore, the organopolysiloxane preferably has at least two alkenyl groups in its molecule. Specifically, R preferably contains 0.001 mol% to 5 mol%, more preferably 0.005 mol% to 3 mol%, more preferably 0.01 mol% to 1 mol%, and even more preferably 0.02 mol% to 0.5 mol%, and most preferably contains vinyl groups. The organopolysiloxane is essentially a linear organopolysiloxane, and some may have branches. It may also be a mixture of two or more molecules with different molecular structures.

[0208] The organopolysiloxane in the outermost / backmost layer is preferably cross-linked by a cross-linking agent, and more preferably by an organic peroxide. Therefore, the outermost / backmost layer is preferably a cured product formed by curing a resin composition containing an organopolysiloxane and an organic peroxide as a cross-linking agent. At this time, the outermost / backmost layer is preferably cured to the extent that the gel content is within the aforementioned desired range. Therefore, the organic peroxide formulated in the outermost / backmost layer is substantially decomposed, and the outermost / backmost layer does not contain organic peroxide, or even if it does contain organic peroxide, it is only in small amounts.

[0209] On the other hand, the organopolysiloxane in the intermediate layer is preferably in an uncrosslinked state, or even if crosslinked, in a partially crosslinked state. Therefore, the intermediate layer is preferably a resin composition comprising a crosslinking agent such as an organopolysiloxane and an organic peroxide. In this case, the intermediate layer is preferably in an uncured state, or even if cured, in a semi-cured state, so that the gel fraction is within the aforementioned desired range. Therefore, the organic peroxide formulated in the intermediate layer is preferably contained in the intermediate layer in a state where it is almost undecomposed.

[0210] As an organic peroxide, examples include: alkyl peroxides such as ditert-tert-butyl peroxide, 2,5-dimethyl-2,5-di(tert-butylperoxy)hexane, and 2,5-dimethyl-2,5-bis(tert-butylperoxy)hexane, and aralkyl peroxides such as 2,4-diisopropylphenyl peroxide. From the viewpoint of crosslinking speed or safety, alkyl peroxides are preferred, especially 2,5-dimethyl-2,5-di(tert-butylperoxy)hexane.

[0211] The amount of organic peroxide in the resin composition forming the intermediate layer and the outermost / backmost layers, based on the total amount of the resin composition, is preferably 0.01% by mass to 10% by mass, more preferably 0.03% by mass to 5% by mass, further preferably 0.05% by mass to 4% by mass, particularly preferably 0.1% by mass to 3% by mass, and even more preferably 0.3% by mass to 2% by mass. If the amount of organic peroxide is within this range, there is a tendency to safely obtain a composition with a sufficient curing speed. Furthermore, as described above, the organic peroxide formulated in the resin composition is substantially decomposed and almost no longer present in the outermost / backmost layers, but preferably present in the intermediate layer at an amount within the above-mentioned formulation range.

[0212] The resin composition is preferably a composable type containing an organopolysiloxane. The composable resin composition is non-liquid (e.g., solid or paste) without self-flowing properties in its uncured state at room temperature (25°C), but can be uniformly mixed using a mixer described later. By using a composable resin composition in this film (4), as described below, the productivity of processing the resin composition into an intermediate layer or an outermost / backmost layer is good.

[0213] Furthermore, as described above, the resin compositions used in the intermediate layer and the outermost / backmost layers may also use resins other than polysiloxanes (organosiloxanes). In this case, the outermost / backmost layers should also be layers formed by curing, for example, a resin composition containing resin and a crosslinking agent in such a way that the gel fraction is within the desired range. Furthermore, the intermediate layer should preferably be formed from a resin composition similarly containing resin and a crosslinking agent, but in this case, the resin composition should preferably be in an uncured state, or even if cured, in a semi-cured state, so that the gel fraction is within the aforementioned desired range.

[0214] The intermediate layer, outermost layer, and backmost layer of the present invention may also contain fillers such as silicon oxide fillers. By including fillers in each layer of the membrane (4), it is easy to set the mechanical properties of the membrane, such as storage modulus or elongation at break, within a suitable range. Furthermore, by using fillers, it is easy to adjust the viscosity or hardness of the resin composition, and the flowability or secondary processing properties of the resin composition are also easily optimized. Moreover, it has the advantage that the hardness can be appropriately adjusted according to the design of the acoustic component or the acoustic characteristics. Furthermore, the filler constitutes part of the gel component when the gel fraction is measured, and the gel fraction of each layer is increased due to the presence of fillers. Even if the gel fraction is increased due to the presence of fillers, the hardness of each layer can be increased in the same way as when the gel fraction is increased by crosslinking.

[0215] Examples of silica-based fillers include fuming silica or precipitated silica, as well as silica-based fillers surface-treated with silane coupling agents. The filler content in each layer is based on the total amount of the resin composition constituting each layer, and is, for example, 10% by mass to 50% by mass, preferably 15% by mass to 40% by mass, and more preferably 20% by mass to 35% by mass. Furthermore, the average particle size of the filler is, for example, 0.01 μm to 20 μm, preferably 0.1 μm to 10 μm, and more preferably 0.5 μm to 5 μm. The average particle size of the filler can be measured using a particle size distribution measuring device based on laser diffraction, etc., as the median particle size (D50).

[0216] In this invention, the resin composition used to form each layer may contain various additives such as heat stabilizers, antioxidants, ultraviolet absorbers, light stabilizers, antibacterial and antifungal agents, antistatic agents, lubricants, pigments, dyes, flame retardants, and impact modifiers within a range that does not cause damage.

[0217] In this membrane (4), the resin compositions used to form the outermost and backmost layers may have the same composition or different compositions. Similarly, the resin composition used to form the intermediate layer may have the same composition as the resin composition used to form the outermost or backmost layer, or it may have different compositions. Furthermore, the composition of the resin composition referred to here means the composition of the resin composition before it hardens.

[0218] In this invention, commercially available products can also be used as organopolysiloxanes. Furthermore, commercially available products containing mixtures of additives such as silicon oxide fillers in addition to organopolysiloxanes can also be used. Specifically, products manufactured by Shin-Etsu Chemical Industry Co., Ltd. under the trade names "KE-597-U" and "KE-594-U" can also be used.

[0219] [Membrane with Release Film] The above-described membrane (4) may also be used as a membrane with a release film attached. The membrane with release film attached includes the above-described membrane (4) and a release film disposed on at least one side of the membrane (4). Furthermore, in the membrane with release film attached, it is preferable to provide release films on both sides of the membrane (4). Moreover, the release film is deposited on the outermost layer or the outermost layer of the membrane (4), or both of these layers.

[0220] The release film can be a resin film or a resin film having a release layer formed by at least one side being treated with a release layer. When the release film has a release layer, it is preferable to deposit the release film onto the film (4) in such a way that the release layer contacts the outermost / backmost layer of the film (4). Examples of resins used as resin films include: polyolefin resins such as polypropylene, acrylic resins, polystyrene resins, polyacetal resins, polyamide resins, polyester resins, polycarbonate resins, ABS resins, polyetheretherketone resins, etc. Among these, polyester resins are preferred, and polyethylene terephthalate resins are preferred. The thickness of the release film is not particularly limited, but is preferably 5 μm or more and 100 μm or less, more preferably 7 μm or more and 80 μm or less, and even more preferably 10 μm or more and 50 μm or less.

[0221] This film (4) is protected by a release film. Therefore, damage to this film (4) is prevented during transportation, etc. Furthermore, as described below, the release film can be the release film deposited on the outermost / backmost layer during the manufacture of this film (4), or a release film can be deposited on the manufactured film (4) separately. Also, this film (4) can be shaped by, for example, shaping as described below, but during shaping, it is advisable to peel the release film from this film (4) and place it in a mold such as a metal mold. As described above, even without a release film, this film (4) has good shape retention before curing due to having specific outermost / backmost layers, and it can also prevent adhesion to the metal mold during shaping.

[0222] [Manufacturing method of this film (4)] This film (4) can be formed by a general forming method, such as lamination, co-extrusion or other extrusion, coating or a combination thereof. Among these, considering the ease of multilayering of the outermost / backside layer and the intermediate layer, lamination is preferred.

[0223] When using lamination molding, it is advisable to first prepare the outermost layer and the backmost layer, and then laminate an intermediate layer between the outermost layer and the backmost layer. More specifically, it is advisable to first prepare a resin composition for obtaining the outermost layer and the backmost layer (resin composition for the outermost layer or the backmost layer), and a resin composition for obtaining the intermediate layer (resin composition for the intermediate layer).

[0224] There are no particular limitations on the resin compositions; for example, they can be obtained by mixing the materials constituting the resin composition. The mixing machine used for mixing can be a known mixing machine such as a single-shaft or twin-shaft extruder, a two-roll or three-roll calender, a roller mill, a plastomill, a Bamboo mixer, a kneader, or a planetary mixer. The mixing temperature is adjusted appropriately according to the type or mixing ratio of the resin, and the presence or type of additives. To inhibit cross-linking (hardening) and moderately reduce the resin viscosity for easy mixing, a temperature of 20°C to 150°C is preferred, more preferably 30°C to 140°C, further preferably 40°C to 130°C, particularly preferably 50°C to 120°C, and especially preferably 60°C to 110°C. The mixing time is sufficient to achieve a uniform mixture of the materials constituting the resin composition, for example, from a few minutes to a few hours, preferably from 5 minutes to 1 hour.

[0225] A laminated body is obtained by laminating the resin composition of the outermost or backmost layer prepared as described above onto a release film using a conventional method. The laminated body is then heated or subjected to other methods to harden the resin composition. This yields a laminated body (hereinafter also referred to as a "laminated film") formed by laminating the outermost or backmost layer onto a release film. The outermost or backmost layer in the laminated film forms a cross-linked structure through hardening, and as described above, the gel fraction is preferably 80% or more. Furthermore, when the release film has a release treatment surface, it is preferable to apply the resin composition of the outermost / backmost layer to the release treatment surface of the release film. Alternatively, the resin composition of the outermost or backmost layer can be laminated between two release films, and then the resin composition can be appropriately hardened by heating or other methods. Afterward, one release film is peeled off to obtain the aforementioned laminated film.

[0226] Furthermore, in this manufacturing method, as described above, a resin composition is applied to the outermost / backmost layer of the release film layer and then cured, thereby obtaining a surface of the outermost / backmost layer that corresponds to the surface shape of the release film. Therefore, by adjusting the surface shape of the release film, the surface shape of the outermost / backmost layer can also be adjusted.

[0227] Next, the film (4) is obtained by laminating an intermediate layer formed of an intermediate layer resin composition between the above-mentioned laminated films. Specifically, the intermediate layer resin composition is fed into the laminated films in an uncured or semi-cured state between two laminated films, for example, between a pair of rollers, from two directions. Here, the intermediate layer resin composition is preferably fed into the laminated films by extrusion from a T-die or the like using an extruder. Furthermore, each laminated film is preferably fed out sequentially with the outermost and backmost layers facing each other. Then, the thickness is adjusted as needed by the gap between the rollers to obtain a laminated body with an uncured or semi-cured intermediate layer formed between the laminated films. This laminated body preferably has a laminated structure of release film / outermost layer / intermediate layer / backmost layer / release film to become the above-mentioned film with a release film attached.

[0228] [Molded Article] This film (4) can be molded into a molded article by forming and hardening it using a mold such as a metal mold. Typically, it is advisable to use a mold to shape it into various molded articles. It is advisable to harden it according to the characteristics of this film (4), preferably by heating, light irradiation, moisture application or a combination of these treatments, preferably by heating. The molded article is preferably an audio component, and more preferably a diaphragm. When obtaining a molded article from this film (4), it is advisable to perform at least the following steps 1 and 2. Step 1: Heating this film (4), forming it using a mold, and hardening this film (4) Step 2: Peeling the formed and hardened film (4) (i.e., the molded article) from the mold.

[0229] The following is a more detailed explanation of each step. (Step 1) In step 1, the film (4) is heated, shaped using a mold, and the film (4) is hardened to form a molded article. The molded article is preferably shaped using a mold to form the desired shape. The forming in step 1 is not particularly limited, and can be carried out by any forming method such as vacuum forming, air-press forming, or pressure forming. Among these, pressure forming is preferred in terms of the ease of forming. That is, in step 1, the film is placed in the mold and thermoformed to obtain a laminate containing the mold and the film, but the film is preferably hot-pressed.

[0230] As a mold, a corresponding mold can be prepared according to the molding method. It is advisable to set the mold with concave and convex shapes that correspond to the shape of the molded article being manufactured. Typically, a metal mold (metal mold) is used as the mold, but a resin mold can also be used. For example, as described below, if the molded article (sound component) has at least one part that is domed or conical, it is advisable to set the mold with concave and convex shapes that correspond to the dome or cone shape. Also, when the surface of the molded article (sound component) has tangent edges, it is advisable to set the mold with concave and convex shapes that correspond to the tangent edges.

[0231] As mentioned above, this film (4) is sometimes attached with a release film. As mentioned above, this film (4) is preferably placed in the mold after the release film is peeled off.

[0232] In step 1, the heated film (4) can be shaped using a mold. For example, the film (4) placed on the mold can be shaped by heating while the mold is in place, or the preheated film (4) can be placed on the mold and then shaped by the mold. These methods can also be combined. Furthermore, the film (4) can be heated by any method. For example, when heating the film placed on the mold, the mold can be heated to utilize the heat conduction, or other methods can be used for heating.

[0233] The heating temperature during shaping or hardening is preferably 180°C to 260°C, more preferably 190°C to 250°C, and even more preferably 200°C to 240°C. If the temperature during shaping or hardening is within this range, there is a tendency for the film (4) to harden at a sufficient rate without deforming due to thermal melting.

[0234] The forming time is preferably 1 second to 5 minutes, more preferably 5 seconds to 4 minutes, further preferably 10 seconds to 3 minutes, and even more preferably 20 seconds to 2 minutes. If the heat treatment time during forming is within this range, there is a tendency for sufficient hardening while maintaining productivity. Furthermore, the film (4) is preferably formed and hardened at the same time, but there is no particular limitation, and it may also be hardened after forming. Furthermore, the forming time refers to the time from forming to hardening of the film (4) in the mold, excluding the mold movement time before forming begins and after forming ends, or the time when demolding the laminate.

[0235] (Step 2) In step 2, the film (4) formed and hardened in step 1 is peeled off from the mold to obtain a molded article. In this invention, since the static friction coefficient of the outermost / backmost layer of the film is low, even without the deposition of a release film, the film can be prevented from adhering to the mold, and the molded article obtained from the film can be easily peeled off from the mold. Furthermore, since the gel fraction of the middle layer of the film does not reach a certain value, the shapeability is high, and the film's conformability to the mold is high. Therefore, the molded article can be manufactured with high forming accuracy. Furthermore, by setting the outermost / backmost layer, the film (4) has high shape retention, and even without a release film, it is easy to operate and can maintain its shape and be easily placed in a metal mold without a release film. Moreover, by not depositing a release film, the step of peeling the release film off the molded article can be omitted, thus making mass production easy.

[0236] In this invention, the gel fraction of the molded article obtained from the above-described film is preferably 80% or more. If the gel fraction is 80% or more, it is easy to obtain a molded article with a storage modulus and mechanical strength suitable for acoustic components. The gel fraction of the molded article is more preferably 85% or more, and even more preferably 90% or more. Furthermore, there is no particular limitation on the upper limit of the gel fraction of the molded article; it can be 100% or less, generally below 100%, for example, 99% or less. Moreover, the gel fraction of the molded article refers to the gel fraction of the entire molded article, and it is advisable to take samples parallel to the thickness direction of the molded article for measurement. The detailed method for measuring the gel fraction is as described above.

[0237] [Uses of the membrane] As described above, the membrane of the present invention is preferably used in audio components, wherein it can be applied to a diaphragm. The audio component of the present invention is formed by hardening the membrane (4), and specifically, it preferably includes the above-described molded article. The diaphragm is more preferably a speaker diaphragm, and is particularly suitable for use as a miniature speaker diaphragm for mobile phones, etc.

[0238] By properly shaping this membrane (4), it can become various acoustic components such as diaphragms. The acoustic component preferably has, for example, at least a portion of it having a dome or cone shape. Also, the acoustic component may have tangent edges on its surface. When it has a dome or cone shape, or has tangent edges, the acoustic component is preferably used as a diaphragm, and more preferably as a loudspeaker diaphragm.

[0239] (Vibrating Plate) To provide a more detailed description of the vibrating plate, there are no particular limitations on its shape; it can be any shape, such as circular, oval, or egg-shaped. Furthermore, a vibrating plate generally has a main body that vibrates in response to electrical signals, etc., and an edge surrounding the main body. The main body of the vibrating plate is usually supported by the edge. As described above, the shape of the vibrating plate can be domed, conical, or a combination of these shapes, or other shapes used for vibrating plates.

[0240] At least a portion of the vibrating plate can be formed by this membrane (4). For example, the main body of the vibrating plate can be formed by this membrane (4), and the edge of the vibrating plate can be formed by other components; or the edge can be formed by this membrane (4), and the main body can be formed by other components. Of course, the main body and the edge can also be integrally formed by this membrane (4), or the entire vibrating plate can be formed by this membrane (4).

[0241] FIG1 is a diagram showing the structure of the vibrating plate 1 according to one embodiment of the present invention, which is the same as that described in this membrane (1). FIG2 is a diagram showing the structure of the vibrating plate 11 according to another embodiment of the present invention, which is the same as that described in this membrane (1). FIG3 is a top view of the vibrating plate 21 according to another embodiment of the present invention, which is also the same as that described in this membrane (1).

[0242] Furthermore, as described above, the diaphragm is a loudspeaker diaphragm, and more preferably a miniature loudspeaker diaphragm. From the viewpoint of suitability for use as a miniature loudspeaker diaphragm, the size of the diaphragm should preferably be 25 mm or less, more preferably 20 mm or less, and the maximum diameter should be 5 mm or more. Furthermore, the term "maximum diameter" refers to the diameter when the diaphragm is circular, and the major diameter when it is oval or egg-shaped.

[0243] The vibrating plate can be formed solely from this membrane (4), or it can be formed from a composite material of this membrane (4) and other components. For example, as described above, any part of the edge or body can be formed from other components.

[0244] Furthermore, in order to improve the secondary processing suitability or dust resistance of the diaphragm, or to adjust or enhance its acoustic characteristics, the surface of the diaphragm may be appropriately coated with an antistatic agent, or subjected to metal vapor deposition or sputtering, or colored (black or white, etc.). Furthermore, it may also be appropriately laminated with metals such as aluminum, or composited with non-woven fabrics, etc.

[0245] (Audio Converter) The audio converter of the present invention is an audio converter having the above-described audio component, preferably a vibrating plate. Typical audio converters are electrical audio converters, including: speakers, handsets, microphones, headphones, etc. Among these, the audio converter is preferably a speaker, preferably a miniature speaker from a mobile phone, etc. [Example]

[0246] Hereinafter, the present invention will be described in detail by way of embodiments, but the present invention is not limited thereto.

[0247] [Evaluation and Measurement Methods] In this embodiment, various physical properties were measured and the membrane was evaluated as described below. Furthermore, "this membrane" refers to the entirety of this membrane (1) to (4). (1) Determination of Gel Fraction (1-1) The gel fraction of this membrane (1) and (2) was determined before and after pressure molding by the following method. Furthermore, as can be seen from the following measurement method, the gel fraction is calculated by including not only the cross-linking components contained in the membrane, but also the insoluble components other than the cross-linking components such as fillers, in the gel component. (A) Cut the sample evenly parallel to the thickness direction of the membrane and collect approximately 100 mg of sample. Determine the mass of the sample (a); (B) Immerse the collected sample in chloroform at 23°C for 24 hours; (C) Remove the solids from the chloroform and vacuum dry at 50°C for 7 hours; (D) Determine the mass of the dried solids (b); (E) Using the masses (a) and (b), calculate the gel fraction according to the following formula (i).

[0248] [Number 3]

[0249] (1-2) This membrane (3) According to the method described in the instruction manual, the gel fraction of the entire membrane before curing, the gel fraction of the outermost / backmost layer of the membrane before curing, and the gel fraction of the entire membrane after curing are determined. When determining the overall gel fraction of the membrane, samples are taken by cutting along a direction parallel to the thickness direction of the membrane. Furthermore, for the intermediate layer of the membrane before curing, it is calculated by the ratio of the gel fraction of the entire membrane before curing and the outermost / backmost layer to the layer thickness.

[0250] (1-3) This membrane (4) The gel fraction of the entire membrane before curing, the gel fraction of the outermost / backmost layer of the membrane before curing, and the gel fraction of the entire membrane after curing are determined according to the method described in the instruction manual. When determining the overall gel fraction of the membrane, samples are taken equally parallel to the thickness direction of the membrane. Furthermore, for the intermediate layer of the membrane (4) before curing, it is calculated by the ratio of the gel fraction of the entire membrane (4) before curing and the outermost / backmost layer to the layer thickness.

[0251] (2) Storage Modulus E' (2-1) The membranes (1) and (2) obtained from the various examples and comparative examples were cut into 4 mm × 8 cm test pieces as test specimens. Using the test specimens, according to JIS K7244-4:1999, a viscoelastic spectrometer "DVA-200 (manufactured by IT Measurement & Control Co., Ltd., Japan)" was used. The test mode was set to tensile, the frequency was 10 Hz, the strain was 0.1%, and the temperature range was 0 to 300°C. The temperature was increased at a heating rate of 3°C / min, and the storage modulus at 20°C and 100°C was measured. Furthermore, the storage modulus at 20°C was measured for the membranes before and after pressure forming. Also, the storage modulus at 100°C was measured for the membranes after pressure forming.

[0252] (2-2) This film (3) Test pieces of 4 mm × 8 cm were cut from the film (3) obtained before and after curing in each example and comparative example, and used as test samples. Using the test samples, measurements were performed using a viscoelastic spectrometer "DVA-200 (manufactured by IT Measurement & Control Co., Ltd., Japan)" according to JIS K7244-4:1999. For the film before pressure forming, the measurement mode was set to tensile, frequency 10 Hz, strain 0.1%, temperature range -100 to 300°C, and the temperature was increased at a heating rate of 3°C / min. The storage modulus at 20°C was measured. For the film after pressure forming, the temperature was increased at a frequency of 10 Hz, strain 0.1%, temperature range -100 to 300°C, and the temperature was increased at a heating rate of 3°C / min. The storage modulus at 20°C and 100°C was measured. Furthermore, measurements were performed in the TD direction.

[0253] (2-3) This film (4) Test pieces of 4 mm × 8 cm were cut from the films (4) obtained before and after curing in each example and comparative example, as test samples. Using the test samples, according to JIS K7244-4:1999, a viscoelastic spectrometer "DVA-200 (manufactured by IT Measurement & Control Co., Ltd., Japan)" was used. The measurement mode was set to tensile, frequency 10 Hz, strain 0.1%, temperature range 0-300°C, and the temperature was increased at a heating rate of 3°C / min. The storage modulus at 20°C was measured for the film before curing. The storage modulus at 20°C and 100°C was also measured for the film after curing. The TD direction was measured.

[0254] (3) Static friction coefficient (surface friction coefficient) (3-1) The static friction coefficients of the outermost surface of the film obtained in each embodiment and comparative example with stainless steel plate (SUS430) and the outermost back surface with stainless steel plate (SUS430) were measured. The outermost surface of the film obtained in each embodiment and comparative example before thermoforming was measured twice, and the static friction coefficient was obtained from the average value of the measurements. The specific method for measuring the static friction coefficient is as follows. Referring to JIS K7125:1999, the surface of the film was kept in contact with the stainless steel plate for 15 seconds before the test began. Then, the measurement was carried out along the longitudinal direction (MD) under the following conditions to evaluate the static friction coefficient with the stainless steel plate. • Apparatus: Plastic film sliding tester (manufactured by Intesco) • Slider: Total mass 200 g (contact area is a square with sides of 63 mm) • Contact area: 400 cm² • Test speed: 100 mm / min • Temperature: 23℃±2℃ • Relative humidity: 50%±10%

[0255] (3-2) This film (4) The static friction coefficient between the outermost surface of the film obtained in each embodiment and comparative example and the stainless steel plate (SUS430) and the outermost back surface of the film obtained in each embodiment and comparative example and the stainless steel plate (SUS430) was measured. The outermost surface and the outermost back surface of the film obtained in each embodiment and comparative example before thermoforming were measured 3 times, and the static friction coefficient was obtained from the average value of these measurements. The specific method for measuring the static friction coefficient is as follows. Referring to JIS K7125 (1999), before the start of the test, the outermost back surface or outermost surface of the film was kept in contact with the stainless steel plate for 15 seconds. Then, under the following conditions, the measurement was carried out along the longitudinal direction (MD) to evaluate the static friction coefficient with the stainless steel plate. • Apparatus: Plastic film sliding tester (manufactured by Intesco) • Slider: Total mass 200 g (contact area is a square with sides of 63 mm) • Contact area: 40 cm² • Test speed: 100 mm / min • Temperature: 23℃±2℃ • Relative humidity: 50%±10%

[0256] (4) Operability (4-a) No damage (4-a-1) This membrane (1), (2) and (4) are evaluated for no damage during the step of peeling off the release film by hand. If the release film is peeled off without damage, it is evaluated as "0"; if a part of the film remains on the release film and is damaged, it is evaluated as "×". Furthermore, the membrane in the state of release film peeling is used for various evaluations and measurements other than no damage. (4-a-2) This membrane (3) In each example and comparative example, this membrane was made with the release film on the outermost and backmost surfaces. The step of peeling off the release film on the outermost and backmost surfaces of this membrane by hand before hardening is evaluated for no damage. If the release film is peeled off without damage, it is evaluated as "0"; if a part of the film remains on the release film and is damaged, it is evaluated as "×". Furthermore, the membrane is used in various evaluations and measurements other than whether it is damaged, in the state of release film peeling.

[0257] (4-b) Shape retention: The shape retention of the membrane before curing obtained in each embodiment and comparative example is evaluated. When the membrane is peeled off from the release film and used for various evaluations or measurements, the membrane that can maintain its shape and is easy to operate is evaluated as "0", and the membrane that cannot maintain its shape and curls, becomes tangled or breaks during operation is evaluated as "×".

[0258] (5) Formability and Shapeability (5-1) This film (1) and (2) (Shapeability) Test pieces of approximately 7 cm × 10 cm were cut from the films obtained in the various examples and comparative examples and used as evaluation samples. The evaluation samples were clamped into a metal mold for a vibrating plate with tangential edges that was preheated to 230°C and pressurized with a pressure of 0.1 MPa. After being held under pressure for 20 seconds, the samples were removed from the metal mold. The samples after removal were visually confirmed. Those that were given the same concave and convex shape as the metal mold were evaluated as "0", and those that were given a concave and convex shape smaller than the metal mold or were not given a concave and convex shape were evaluated as "×".

[0259] (5-2) This membrane (3) The membrane obtained from each embodiment and comparative example is cut into test pieces of about 7 cm × 10 cm as evaluation samples. The evaluation sample is clamped into a metal mold for a vibrating plate with a dome-shaped tangent edge that has been preheated to 230°C, and pressure is applied at 0.1 MPa. After being held under pressure for 20 seconds, the sample is removed from the metal mold.

[0260] (5-3) This membrane (4) Test pieces of approximately 7 cm × 10 cm were cut from the membranes obtained in the various examples and comparative examples and used as evaluation samples. The evaluation samples were clamped into a metal mold for a vibrating plate with tangential edges that was preheated to 230°C and pressurized with a pressure of 0.1 MPa. After being held under pressure for 20 seconds, the samples were removed from the metal mold. The samples after removal were visually confirmed. Those with a concave-convex shape that was exactly the same as that of the metal mold were evaluated as "0", and those with a concave-convex shape that was only smaller than that of the metal mold or without a concave-convex shape were evaluated as "×".

[0261] (6) Adhesion to the metal mold (6-1) Similar to the evaluation of the formability and shapeability of the film (1), (2) and (4) obtained in each embodiment and comparative example, test pieces of about 7 cm × 10 cm were cut from the film and used as evaluation samples. The evaluation samples were clamped into a metal mold for a vibrating plate that was preheated to 230°C, and pressure was applied at 0.1 MPa. After being held under pressure for 20 seconds, the samples were removed from the metal mold. When the evaluation samples were removed from the metal mold, those that were easy to remove and did not adhere to the metal mold were evaluated as "0", and those that adhered to or remained in the metal mold were evaluated as "×".

[0262] (6-2) This film (3) Similar to the above evaluation of formability and shapeability, test pieces of approximately 7 cm × 10 cm were cut from the films obtained in each example and comparative example as evaluation samples. The evaluation samples were clamped into a metal mold for a vibrating plate that was preheated to 230°C, and pressure of 0.1 MPa was applied. After being held under pressure for 20 seconds, the samples were removed from the metal mold.

[0263] (7) Elongation at break was measured in the TD direction of the hardened film at a tensile speed of 200 mm / min and at 23°C, according to the method of JIS K7161:2014.

[0264] (8) Surface roughness (Ra) For the roughened surface of the release film, a contact surface roughness meter Surf Coder ET4000A (manufactured by Kosaka Research Institute) was used to measure along the longitudinal direction of the film under the conditions of a stylus tip radius of 0.5 mm, a measurement length of 8.0 mm, a reference length of 8.0 mm, a critical value of 0.8 mm, and a measurement speed of 0.2 mm / s. The arithmetic mean roughness (Ra) was calculated.

[0265] Example 1-1 <Raw Materials> ・Polysiloxane (A-1): A mixture of organic polysiloxane and silicon oxide (trade name "KE-597-U", manufactured by Shin-Etsu Chemical Co., Ltd.) ・Organic peroxide composite polysiloxane (B-1) (hereinafter referred to as "organic peroxide"): Polysiloxane containing approximately 40% 2,5-dimethyl-2,5-di(tertiary butylperoxy)hexane (trade name "C-8B", manufactured by Shin-Etsu Chemical Co., Ltd.)

[0266] Using a mixer, 100 parts by weight of polysiloxane rubber (A-1) and 1 part by weight of organic peroxide (B-1) were mixed at 90°C for 5 minutes to obtain a composable resin composition (1). A PET film (1) with a rough surface roughness (Ra) of 0.98 μm was prepared as a release film and fed along two calendering rolls with the rough surface on the inside. The resin composition (1) was placed between the release films, and a bank was formed between the rolls at a roll temperature of 90°C. The thickness of the resin composition (1) was adjusted to 100 μm to obtain a polysiloxane film with a release film attached. The obtained polysiloxane film was irradiated with radiation. After irradiation, the release films on both sides were peeled off to obtain a sample of the polysiloxane film. Assuming the obtained sample is molded into a finished product through shaping, it is hardened using a simple method of heating one side at 200°C for 2 minutes while simultaneously pressing it under a pressure of 0.2 MPa using two flat plates. For the sample before pressing, the surface friction coefficient, gel fraction, and storage modulus were measured to evaluate operability, shapeability, and adhesion to the metal mold. Furthermore, for the sample after pressing, the gel fraction and storage modulus were measured. The results are shown in Table 1. The surface friction coefficient of this sample did not change before and after pressing.

[0267] Comparative Example 1-1: A heat treatment at 200°C for 2 minutes was performed to replace radiation irradiation. Otherwise, the sample was obtained using the same method as in Example 1-1. For the sample before pressure molding, the surface friction coefficient, gel fraction, and storage modulus were measured to evaluate operability, shapeability, and adhesion to the metal mold. Furthermore, for the sample after pressure molding, the gel fraction and storage modulus were measured. Moreover, based on the gel fraction value, it can be determined that the film of Comparative Example 1-1 is a non-curing film.

[0268] [Table 1] Table 1 Example 1-1 Comparative Example 1-1 raw material Polysiloxane rubber A-1 100 100 Organic peroxides B-1 1 1 evaluate Before pressure molding Surface friction coefficient 2.0 1.9 Gel fraction (%) 71.4 96.1 E'@20℃(MPa) 2.4 6.2 Formability 〇 × Operability Is there any damage? 〇 〇 Shape retention 〇 〇 Inhibit adhesion to metal molds 〇 〇 After pressure molding Gel fraction (%) 95.7 96.1 E'@20℃(MPa) 5.0 6.2 E'@100℃(MPa) 4.2 4.6 E' 100 / E' 20 0.8 0.7

[0269] As shown in Table 1, the polysiloxane film with release film in Example 1-1 is semi-crosslinked by irradiation, thus it can be peeled off from the release film without damage. After peeling off the release film, it also maintains a moderate film shape and has excellent workability. Furthermore, the film after pressure molding (after hardening) satisfies the viscoelastic properties described in (b) to (d) above. Therefore, if a diaphragm is formed from the film of Example 1-1, it is expected to obtain excellent sound quality and playback performance.

[0270] The film obtained in Example 1-1 was evaluated for shapeability using the above method, and the results showed that it exhibited shapeability suitable for practical use. Furthermore, in the evaluation of adhesion to the metal mold, when the evaluation sample was removed from the metal mold, the evaluation sample of the film obtained in Example 1-1 was easily removed without adhering to the metal mold. On the other hand, it can be seen that the film of Comparative Example 1-1, being fully hardened, lacked curability, was harder, had insufficient shapeability, and poor formability.

[0271] Example 2-1 <Raw Materials> ・Polysiloxane (A-1): A mixture of organic polysiloxane and silicon oxide (trade name "KE-597-U", manufactured by Shin-Etsu Chemical Co., Ltd.) ・Organic peroxide composite polysiloxane (B-1) (hereinafter referred to as "organic peroxide"): Polysiloxane containing approximately 40% 2,5-dimethyl-2,5-di(tertiary butylperoxy)hexane (trade name "C-8B", manufactured by Shin-Etsu Chemical Co., Ltd.)

[0272] Using a mixer, 100 parts by mass of polysiloxane rubber (A-1) and 1 part by mass of organic peroxide (B-1) were mixed at 90°C for 5 minutes to obtain a composable resin composition (1). A PET film (1) with a rough surface roughness (Ra) of 0.98 μm was prepared as a release film and fed along two calendering rolls with the rough surface on the inside. The resin composition (1) was placed between the release films, and a bank was formed between the rolls at a roll temperature of 90°C. The thickness of the resin composition (1) was adjusted to 100 μm to obtain a polysiloxane film with a release film attached. The obtained polysiloxane film was irradiated with radiation. After irradiation, the release films on both sides were peeled off to obtain a sample of the polysiloxane film. Assuming the obtained sample is molded into a finished product through shaping, it is hardened using a simple method of heating at 200°C for 2 minutes while simultaneously pressing it under a pressure of 0.2 MPa using two flat plates. For the sample before pressing, the surface friction coefficient, gel fraction, and storage modulus were measured to evaluate operability, shapeability, and adhesion to the metal mold. Furthermore, for the sample after pressing, the gel fraction and storage modulus were measured. The results are shown in Table 1.

[0273] Comparative Example 2-1: A PET film (2) with a surface roughness (Ra) of 0 μm was used as the release film. Otherwise, samples were obtained using the same method as in Example 2-1. For the sample before pressure molding, the surface friction coefficient, gel fraction, and storage modulus were measured to evaluate operability, shapeability, and adhesion to the metal mold. For the sample after pressure molding, the gel fraction and storage modulus were measured.

[0274] Comparative Example 2-2: A heat treatment at 200°C for 2 minutes was performed to replace radiation irradiation. Otherwise, the sample was obtained using the same method as in Example 2-1. For the sample before pressure molding, the surface friction coefficient, gel fraction, and storage modulus were measured to evaluate operability, shapeability, and adhesion to the metal mold. Furthermore, for the sample after pressure molding, the gel fraction and storage modulus were measured.

[0275] [Table 2] Table 2 Example 2-1 Comparative Example 2-1 Comparative Example 2-2 raw material Polysiloxane rubber A-1 100 100 100 Organic peroxides B-1 1 1 1 evaluate Before pressure molding Surface friction coefficient 2.0 >5.0 1.9 Gel fraction (%) 71.4 78.3 96.1 E'@20℃(MPa) 2.4 1.9 6.2 Formability 〇 〇 × Operability Is there any damage? 〇 〇 〇 Shape retention 〇 〇 〇 Inhibit adhesion to metal molds 〇 × 〇 After pressure molding Gel fraction (%) 95.7 95.9 96.1 E'@20℃(MPa) 5.0 7.3 6.2 E'@100℃(MPa) 4.2 5.6 4.6 E' 100 / E' 20 0.8 0.8 0.7

[0276] As shown in Table 1, the polysiloxane film with release film in Example 2-1 is semi-crosslinked by irradiation. Therefore, it can be peeled off from the release film without damage. After peeling off the release film, it also maintains a moderate film shape and has excellent workability. Furthermore, the film after pressure molding (after hardening) satisfies the viscoelastic properties described in (b) to (d) above. Therefore, if a diaphragm is formed from the film of Example 2-1, it is expected to obtain excellent sound quality and playback performance.

[0277] Regarding the film obtained in Example 2-1, the shapeability was evaluated using the above method, and the results showed that it exhibited a degree of shapeability suitable for practical use. Furthermore, in the evaluation of adhesion to the metal mold, when the evaluation sample was removed from the metal mold, the evaluation sample of the film obtained in Example 2-1 was easily removed without adhering to the metal mold. On the other hand, it can be seen that the film of Comparative Example 2-1, due to its higher surface friction coefficient (static friction coefficient), was difficult to detach from the metal mold and thus difficult to handle. Furthermore, it can be seen that the film of Comparative Example 2-2, being fully hardened, lacked curability, was harder, had insufficient shapeability, and poor formability.

[0278] Example 3-1 Prepare a PET film (1) with a surface roughness (Ra) of 0.88 μm and a PET film (2) with a surface roughness (Ra) of 1.9 μm as release films. Lay a 20 μm thick polysiloxane rubber (trade name "TSE2571-5U", manufactured by Momentive Performance Materials) between the PET film (1) and the PET film (2) and allow it to harden to prepare a laminated film. Peel off the PET film (1) to expose the hardened polysiloxane. Using a planetary mixer, 100 parts by weight of a mixture of organopolysiloxane and silicon oxide (trade name "KE-597-U", manufactured by Shin-Etsu Chemical Co., Ltd.) and 1 part by weight of an organic peroxide (trade name "C-8B", manufactured by Shin-Etsu Chemical Co., Ltd., containing approximately 40% by weight of 2,5-dimethyl-2,5-di(tert-butylperoxy)hexane as an organic peroxide) were mixed at 90°C for 10 minutes to obtain a composable resin composition (1). The two laminated films obtained above were fed along two 100 mm diameter calendering rolls with the exposed polysiloxane surface facing inwards. Resin composition (1) was added between the laminated films between the calendering rolls. At room temperature (25°C) and roll temperature (90°C), a bank was formed between the rolls, resulting in an intermediate layer thickness of 100 μm. This yielded a film containing a release film, an outermost layer, an intermediate layer, a backmost layer, and another release film. The outermost and backmost layers had a thickness of 20 μm. The two release films were successfully peeled off under these conditions without damage. Shape retention was also good. The gel fraction and storage modulus at 20°C were measured for the film after release film peeling. The results are shown in Table 1.

[0279] Assuming that a molded article is manufactured by shaping, the above-obtained membrane is hardened by a simple method of heating one side at 220°C for 2 minutes while simultaneously pressing it under a pressure of 0.2 MPa using two flat plates. For the obtained hardened membrane, the gel fraction (overall membrane), storage modulus at 20°C and 100°C, and tensile elongation at break are measured. The measurement results are shown in Table 1.

[0280] Example 3-2 The release film (PET film (2)) used in Example 3-1 was used as a standalone unit instead of the laminated film. It was fed along two calendering rolls with a diameter of 100 mm. The resin composition (1) was added between the release films between the calendering rolls. At room temperature of 25°C and roll temperature of 90°C, a bank was formed between the rolls, making the thickness of the resin layer 100 μm, thus obtaining a film containing a release film / single-layer film / release film with a release film attached. The film with the release film attached was semi-cured by a simple method of heating at 150°C for 2 minutes and pressing it with two flat plates at a pressure of 0.2 MPa, thus obtaining a film with the storage modulus and gel fraction described in Table 1. The two release films were peeled off under the above conditions, and the peeling was successful without any damage to the film. In addition, the shape retention was also good. The gel fraction and storage modulus at 20°C were measured for the film after the release film was peeled off. The measurement results are shown in Table 1. Furthermore, the membrane was pressure-cured under the same conditions as in Example 3-1, and the gel fraction (whole membrane), storage modulus at 20°C and 100°C, and tensile elongation at break were measured for the cured membrane.

[0281] Comparative Example 3-1: In Example 3-2, no semi-curing was performed. Otherwise, a film with the gel fraction described in Table 1 was obtained in the same manner as in Example 3-2. Under the above conditions, two release films were peeled off from the obtained film with the release film attached, resulting in partial damage to the film. Therefore, a definite value for the storage modulus E' could not be obtained.

[0282] The membrane was cured, and its physical properties were evaluated using the method described above. As a curing method, a simple method was adopted, which involved heating one side at 220°C for 2 minutes while simultaneously pressing it under a pressure of 0.2 MPa using two flat plates. For the cured membrane obtained, the gel fraction, storage modulus at 20°C and 100°C, and tensile elongation at break were measured.

[0283] The evaluation results of Examples 3-1, 3-2 and Comparative Example 3-1 are shown in Table 3 below.

[0284] [Table 3] Table 3 Example 3-1 Example 3-2 Comparative Example 3-1 constitute Topmost layer / Middle layer / Backmost layer (Two types of three-layer) single layer single layer pressurization Before forming Storage modulus E' (MPa) 20℃, 10 Hz 1.5 4.1 <0.1 Gel fraction (%) Membrane as a whole 66 76 54 Top / back layer 97 - - Intermediate layer 54 - - Layer thickness (μm) 20 / 100 / 20 100 100 Operability Is there any damage? 〇 〇 × Shape retention 〇 〇 × pressurization After forming Storage modulus E' (MPa) 20℃, 10 Hz 5.1 7.7 7.7 100℃, 10 Hz 3.7 5.2 5.2 Comparison (100℃ / 20℃) 0.73 0.68 0.68 Gel fraction (%) Membrane as a whole 95 95 95 Elongation at break (%) >400 >400 >400

[0285] The membrane of Example 3-1, which has an intermediate layer and an outermost / backmost layer, and the outermost / backmost layer is a highly hardened layer, can be peeled off from the release film without damage. Furthermore, since the outermost / backmost layer is relatively hard, it retains a suitable film shape after the release film is peeled off, resulting in excellent operability. Moreover, since the hardened membrane satisfies the viscoelastic properties described in (b) to (d) above, if a diaphragm is formed from the membrane of Example 3-1, it is expected to obtain excellent sound quality and playback characteristics. Furthermore, the hardened membrane has a high elongation at break, making it less prone to breakage due to prolonged vibration, and is also expected to provide a durable audio component.

[0286] Furthermore, the membrane with the release film attached in Example 3-2, which is a semi-cured monolayer membrane, can be peeled off from the release film without damage. Also, this monolayer membrane is a relatively hard layer, and after the release film is peeled off, it retains its membrane shape appropriately, resulting in excellent operability.

[0287] The formability and shapeability of the films obtained in Examples 3-1 and 3-2 were evaluated using the above method, and the results showed that they exhibited formability and shapeability to a degree that is practically usable. Furthermore, in the evaluation of adhesion to the metal mold, when the evaluation sample was removed from the metal mold, the evaluation sample of the films obtained in Examples 3-1 and 3-2 was also easily removed without adhering to the metal mold.

[0288] In contrast, the relatively soft release film of Comparative Example 3-1 was damaged when the release film was peeled off. Also, it was difficult to maintain its shape properly, resulting in poor operability.

[0289] Furthermore, the formability and shapeability of the film of Comparative Example 3-1 were evaluated, and the results showed that the formability and shapeability were of a practical level. However, in the evaluation of the adhesion to the metal mold, the evaluation sample adhered to and remained on the metal mold, which was an undesirable situation.

[0290] Example 4-1 Prepare a PET film (1) with a surface roughness (Ra) of 0.88 μm and a PET film (2) with a surface roughness (Ra) of 1.9 μm as release films for the outermost / backmost layers. Lay a 20 μm thick polysiloxane rubber (trade name "TSE2571-5U", manufactured by Momentive Performance Materials) between the PET film (1) and the PET film (2) and allow it to harden to prepare a laminated film. Peel off the PET film (1) to expose the hardened polysiloxane.

[0291] Using a planetary mixer, 100 parts by weight of a mixture of organic polysiloxane and silicon oxide (trade name "KE-597-U", manufactured by Shin-Etsu Chemical Co., Ltd.) and 1 part by weight of an organic peroxide (trade name "C-8B", manufactured by Shin-Etsu Chemical Co., Ltd., containing approximately 40% by weight of 2,5-dimethyl-2,5-di(tert-butylperoxy)hexane as an organic peroxide) were mixed at 90°C for 10 minutes to obtain a composable resin composition (1). The above-mentioned laminated film was fed through two calendering rolls with the hardened polysiloxane exposed surface facing inwards. Resin composition (1) was added between the laminated films between the calendering rolls. At room temperature of 25°C and roll temperature of 90°C, a bank was formed between the rolls, making the thickness of the intermediate layer 100 μm, thus obtaining a film with a release film attached, comprising a release film / outermost layer / intermediate layer / backmost layer / release film. Two release films were peeled off from the obtained film with the release film attached by hand to obtain the film. The gel fraction of the outermost / backmost layer and intermediate layer, the static friction coefficient of the outermost / backmost layer, and the storage modulus of the film at 20°C were measured. The measurement results and the evaluation results of operability are shown in Table 1.

[0292] Assuming that a molded article is manufactured by shaping, the above-obtained membrane is hardened by a simple method of heating one side at 220°C for 2 minutes and pressing it under a pressure of 0.2 MPa using two flat plates. For the obtained hardened membrane, the gel fraction (whole membrane), storage modulus and tensile elongation at break are measured.

[0293] Comparative Example 4-1 A release film (PET film (2)) was used as a standalone unit instead of a laminated film. It was fed along two calendering rolls with a diameter of 100 mm. A resin composition (1) was added between the release films between the calendering rolls. At room temperature of 25°C and roll temperature of 90°C, a bank was formed between the rolls, making the thickness of the intermediate layer 100 μm, thus obtaining a film with a release film attached, comprising a release film / intermediate layer / release film. Two release films were peeled off from the obtained film with a release film attached to obtain the present film. The present film comprises a single intermediate layer. The gel fraction and static friction coefficient of the present film (intermediate layer) were measured, and the storage modulus at 20°C was measured. The measurement results and the evaluation results of operability are shown in Table 1.

[0294] Assuming the forming process, the above-obtained membrane was hardened by a simple method of heating one side at 220°C for 2 minutes while simultaneously pressing it under a pressure of 0.2 MPa using two flat plates. For the hardened membrane, the gel fraction, storage modulus, and tensile elongation at break were measured.

[0295] Comparative Example 4-2 A release film (PET film (2)) was used as a standalone unit instead of a laminated film. It was fed along two calendering rolls with a diameter of 100 mm. A resin composition (1) was added between the release films between the calendering rolls. At room temperature of 25°C and a roll temperature of 90°C, a bank was formed between the rolls, making the thickness of the intermediate layer 100 μm, thus obtaining a film with a release film attached, comprising a release film / intermediate layer / release film. The intermediate layer was hardened by heating the film with the release film attached using a simple method of heating at 220°C for 2 minutes while pressing it with two flat plates at a pressure of 0.2 MPa. After the intermediate layer was hardened, the two release films were peeled off from the obtained film with the release film attached to obtain the film. The film contains a single intermediate layer. The static friction coefficient and storage modulus at 20°C of the film (intermediate layer) were measured. The measurement results and the evaluation results of operability are shown in Table 1.

[0296] Furthermore, since the membrane has been completely hardened, the gel fraction, storage modulus and tensile elongation at break of the membrane were measured.

[0297] The evaluation results of Example 4-1 and Comparative Examples 4-1 to 4-2 are summarized in Table 4 below.

[0298] [Table 4] Table 4 Example 4-1 Comparative Example 4-1 Comparative Example 4-2 constitute Topmost layer / Middle layer / Backmost layer (Two types of three-layer) single layer single layer pressurization Before forming Gel fraction (%) Membrane as a whole 66 54 95 Top / back layer 97 - - Intermediate layer 54 - - Layer thickness (μm) 20 / 100 / 20 100 100 Static friction coefficient of the outermost / backmost layer 1.3 4.9 1.8 Elastic modulus E' (MPa) @ 20℃, 10 Hz 1.5 Unable to determine 7.7 Operability Is there any damage? 〇 × 〇 Shape retention 〇 × 〇 After pressure molding Formability and shaping properties 〇 〇 × Gel fraction (%) overall 95 95 95 Adhesion to metal molds none have none Elastic modulus E' (MPa) 20℃ (10 Hz) 5.1 7.7 7.7 100℃ (10 Hz) 3.7 5.2 5.2 Comparison (100℃ / 20℃) 0.73 0.68 0.68 Elongation at break (%) >400 >400 >400

[0299] The membrane in the above embodiments has a hardenable intermediate layer and an outermost / backmost layer, and the static friction coefficient of the outermost / backmost layer is 3 or less. Therefore, it can be fully shaped by molding and has good conformability to metal molds, while preventing the membrane from sticking to the metal mold during molding. Furthermore, since the outermost / backmost layer is a relatively hard layer, it retains a suitable membrane shape after the release film is peeled off, resulting in excellent operability and easy placement in the metal mold. Moreover, since the hardened membrane satisfies the viscoelastic properties described in (c) to (e) above, it is expected that excellent sound quality and playback performance can be obtained from the membrane-molded diaphragm and other audio components of Example 4-1. In addition, the hardened membrane has a high elongation at break, making it less prone to breakage due to long-term vibration, and it is also expected to provide audio components with excellent durability.

[0300] In contrast, the film of Comparative Example 4-1 has a higher coefficient of static friction, resulting in good shapeability and conformability to metal molds. However, during molding, the film adheres to the metal mold. Furthermore, because it does not employ a multi-layer structure with an outermost / backmost layer and a hardening intermediate layer, the film is relatively soft overall, making it difficult to maintain its shape properly after the release film is peeled off, resulting in poor operability. Comparative Example 4-2, on the other hand, has a lower coefficient of static friction, so there is no film adhesion to the metal mold during molding. However, because it does not employ a multi-layer structure with an outermost / backmost layer and a hardening intermediate layer, the film is relatively hard overall, making it difficult to fully shape during molding, and its conformability to metal molds is also insufficient. [Industrial Applicability]

[0301] The molded articles obtained from the membrane of the present invention can be easily removed from the metal mold during the manufacturing process, and therefore can be applied to various molded articles. In particular, it can be used as a membrane for audio components such as diaphragms, which is of great industrial significance. [Simplified Explanation of the Diagram]

[0010] FIG1 is a cross-sectional view showing the structure of a miniature loudspeaker diaphragm 1 according to one embodiment of the present invention. FIG2 is a cross-sectional view showing the structure of a miniature loudspeaker diaphragm 11 according to another embodiment of the present invention. FIG3 is a top view showing the structure of a miniature loudspeaker diaphragm 21 according to another embodiment of the present invention.

Claims

1. A membrane having curability and viscoelastic properties as described in (a), and in its cured state having viscoelastic properties as described in (b) to (d): (a) a storage modulus E' of 0.1 MPa to 500 MPa at a temperature of 20°C and a frequency of 10 Hz; (b) a storage modulus E'20 of 0.1 MPa to 500 MPa at a temperature of 20°C and a frequency of 10 Hz; (c) a storage modulus E'100 of 0.1 MPa to 500 MPa at a temperature of 100°C and a frequency of 10 Hz; (d) the ratio of E'100 / E'20 is 0.4 to 1.

0.

2. The membrane in request item 1 is a single layer.

3. The membrane, as requested in item 1 or 2, has thermosetting properties.

4. The membrane of claim 1 or 2 has a cross-linked structure.

5. The membrane of request item 1 or 2 has a gel fraction of less than 90%.

6. The membrane in claim 1 or 2 is a polysiloxane membrane.

7. The film of claim 1 or 2 has a static friction coefficient of 3 or less on at least one side.

8. The membrane of request item 2 has a gel fraction of 60% to 90%.

9. The membrane of claim 1, comprising an outermost / backmost layer including a hardened resin layer, and at least one hardened intermediate layer disposed between the outermost / backmost layers, wherein the static friction coefficient of the outermost / backmost layer is 3 or less.

10. The membrane of claim 9, wherein the gel content of the intermediate layer is 0% or more but less than 80%.

11. The membrane of claim 9, wherein the gel fraction of the outermost / backside layer is 80% or more.

12. A diaphragm for an acoustic component, comprising a diaphragm as claimed in any one of claims 1 to 11.

13. The diaphragm for the acoustic components as requested in item 12 is a diaphragm for a diaphragm.

14. A membrane with a release film attached, comprising a membrane as claimed in any one of claims 1 to 11, and a release film disposed on at least one side of the membrane.

15. An acoustic component formed by hardening a membrane as claimed in any one of claims 1 to 11.

16. An audio converter having an audio component as claimed in claim 15.

17. A method of manufacturing a membrane as claimed in any one of claims 1 to 11, comprising the step of curing at least a portion of one or more resin layers used to constitute the membrane.

18. A method for manufacturing a membrane as claimed in claim 17, comprising the step of laminating a cured resin layer with a resin layer having curability.

19. A method for manufacturing a membrane as claimed in claim 2, comprising the step of irradiating with radiation.

20. A method for manufacturing a film as claimed in claim 19, wherein after irradiating a resin layer deposited on a release film with radiation, the release film is peeled off from the resin layer.

21. A method for manufacturing a film as claimed in claim 19 or 20, comprising the steps of: depositing a resin layer between two release films having a surface roughness (Ra) of 0.10 to 6.00 μm; hardening the deposited resin layer; and peeling at least one of the release films from the hardened resin layer.

22. A method of manufacturing a membrane as claimed in any one of claims 9 to 11, comprising the step of laminating an uncured or semi-cured intermediate layer between a cured outermost / backmost layer.

23. A method for manufacturing an acoustic component, wherein a mold is used to shape the membrane of any one of claims 1 to 11.

24. The method for manufacturing an acoustic component as claimed in claim 23, comprising the step of heating the diaphragm before placing it in the mold.

25. The method for manufacturing an acoustic component as claimed in claim 23 or 24, wherein the heating temperature during shaping is above 180°C and below 260°C.

26. The method of manufacturing an acoustic component as claimed in claim 23 or 24, wherein the shaping time is more than 1 second and less than 5 minutes.

27. The method of manufacturing the acoustic component as claimed in claim 23 or 24 is to shape it by any of the following methods: pressure forming, vacuum forming and air forming.

28. A method for manufacturing an acoustic component, wherein a mold is used to shape a release liner as claimed in claim 14.

29. Use of the diaphragm as claimed in any one of claims 1 to 11, for use in acoustic components.

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