JP7516879B2 - Acoustic member, laminate for acoustic member, method for manufacturing acoustic member, laminate for thermoforming, and method for manufacturing molded article - Google Patents

Description

The present invention relates to acoustic members, laminates such as laminates for acoustic members, and methods for manufacturing molded products such as acoustic members, and in particular to acoustic members, laminates for acoustic members, and methods for manufacturing acoustic members, which can be suitably used as diaphragms for electroacoustic transducers, particularly speaker diaphragms.

For example, the widespread use of small electronic devices such as smartphones, PDAs, notebook computers, DVDs, LCD televisions, digital cameras, and portable music devices has led to an increased demand for small speakers (usually called micro-speakers) and small receivers used in these electronic devices, as well as small electro-acoustic transducers such as microphones and earphones.

In general, diaphragms used in electroacoustic transducers, and speaker diaphragms in particular, are required to have a specific range of elastic modulus to widen the reproduction frequency band, a high tensile yield elongation so that repeated vibration over a long period of time does not cause deformation and change in sound quality, and high toughness so that they do not break even after repeated vibration over a long period of time. Furthermore, when used near the voice coil, which is the driving source of the speaker, or in car speakers, the diaphragm is exposed to high temperatures for long periods of time, so it needs to have heat resistance sufficient to withstand such conditions of use.

For example, Patent Document 1 discloses a method for manufacturing a diaphragm in which polyether ether ketone resin is laminated on both sides of a silicone rubber composition, and describes that the diaphragm has excellent heat resistance, durability, and acoustic properties.

Patent Document 2 also discloses a sheet for diaphragms formed by sequentially laminating a release sheet, a first layer made of an uncured liquid silicone composition, and a second layer mainly containing thermoplastic polyurethane, and a method for manufacturing a diaphragm using the sheet for diaphragms. In the method for manufacturing a diaphragm, the sheet for diaphragms is set in a mold and molded, and then the release sheet is peeled off from the molded product to manufacture a diaphragm. Patent Document 2 also shows that the use of the sheet for diaphragms can improve the production efficiency of diaphragms with excellent sound quality and heat resistance.

JP 2018-064150 A JP 2018-152817 A

However, the diaphragm described in Patent Document 1 has polyether ether ketone resin laminated on both sides of the silicone rubber composition, so the elastic modulus of the film constituting the diaphragm as a whole is high, and there is a risk of a narrow reproduction frequency band. In addition, not only is there concern that the film is prone to yielding, which could cause changes in sound quality, but it also has insufficient toughness and may break. Furthermore, although polyether ether ketone resin has excellent heat resistance among thermoplastic resins, it has a glass transition temperature near 150°C, and above this temperature the elastic modulus drops significantly, so depending on the usage environment, it does not have sufficient heat resistance.

On the other hand, when silicone resin is used alone, if the degree of crosslinking or the proportion of insoluble matter after curing is low, the elastic modulus will be low, raising concerns that handling properties and acoustic characteristics may deteriorate. Patent Document 1 only describes a laminate of silicone resin and polyether ether ketone resin, and not only is there no description of the properties of silicone resin when used alone, but there is also no description or suggestion of the optimal degree of crosslinking or proportion of insoluble matter for silicone resin when used as an acoustic component.

In addition, when a diaphragm is manufactured using the diaphragm sheet described in Patent Document 2, the diaphragm includes a second layer that mainly contains thermoplastic polyurethane, and therefore heat resistance may be insufficient. Furthermore, since the first layer is made of a liquid silicone composition, the productivity of manufacturing the diaphragm sheet may decrease, and further, the liquid silicone composition may flow out during transportation or when forming a diaphragm from the diaphragm sheet, and handling properties are also insufficient.

The present invention has been made under these circumstances, and has an object to provide an acoustic component having an elastic modulus within an appropriate range and having high heat resistance, toughness, and tensile yield elongation.
Another object of the present invention is to provide a laminate for acoustic members that can produce heat-resistant acoustic members with good productivity and ease of handling.

As a result of intensive research, the inventors have succeeded in discovering an acoustic component and a laminate for an acoustic component that can solve the problems of the conventional technology described above, and have completed the present invention.

That is, the present invention provides the following [1] to [41].
[1] An acoustic component comprising a resin component containing an organopolysiloxane (A), characterized in that the proportion of insoluble matter after immersion in chloroform for 24 hours is 50% or more.
[2] The acoustic component according to the above [1], which comprises a film (X1) containing organopolysiloxane (A) and having a proportion of insoluble matter of 50% or more after immersion in chloroform for 24 hours.
[3] The acoustic component according to the above [2], which consists of a single layer of the film (X1).
[4] The acoustic component according to any one of the above [1] to [3], wherein the degree of crosslinking of the organopolysiloxane (A) is 35% or more.
[5] An acoustic component according to any one of the above [1] to [4], having a tensile yield elongation of 20% or more.
[6] An acoustic component according to any one of the above [1] to [4], which does not have a yield point.
[7] The acoustic member according to any one of the above [1] to [6], wherein the ratio (E ₁₀₀ /E ₂₀ ) of the tensile storage modulus at 20° C. (E ₂₀ ) to the tensile storage modulus at 100° C. (E ₁₀₀ ) is 0.5 or more and 1.2 or less.
[8] The acoustic member according to any one of the above [1] to [7], having a tensile storage modulus (E ₂₀ ) at 20° C. of 800 MPa or less.
[9] An acoustic component according to any one of the above [1] to [8], having a tensile breaking elongation of 200% or more.
[10] The acoustic component according to any one of the above [1] to [9], wherein the resin component is a millable type containing an organopolysiloxane (A).
[11] The acoustic component according to any one of the above [1] to [10], wherein the resin component has a type A durometer hardness of 30 or more and 90 or less.
[12] The acoustic member according to any one of [1] to [11] above, having at least one of a dome shape and a cone shape.
[13] An acoustic component according to any one of the above [1] to [12], having a tangential edge on the surface.
[14] The acoustic member according to any one of the above [1] to [13], which is a diaphragm for an electroacoustic transducer.
[15] The acoustic component according to any one of the above [1] to [14], which is a speaker diaphragm.

[16] A laminate for acoustic components, comprising a curable resin layer (X) made of a millable type resin component containing an organopolysiloxane (A), and a resin layer (Y) laminated on at least one surface of the resin curable layer (X), wherein the resin layer (Y) is peelable from the curable resin layer (X) after curing.
[17] The laminate for acoustic components according to the above [16], wherein the resin layer (Y) is directly laminated on at least one surface of the curable resin layer (X).
[18] The laminate for acoustic components according to the above [16] or [17], wherein the resin layer (Y) is laminated on both sides of the curable resin layer (X).
[19] The laminate for acoustic components according to any one of [16] to [18] above, wherein the glass transition temperature of the resin (B) constituting the resin layer (Y) is 250° C. or lower.
[20] The laminate for acoustic components according to any one of [16] to [19] above, wherein the resin (B) is at least one selected from the group consisting of polyetherimide, polyethylene terephthalate, polymethylpentene, polyether ether ketone, polysulfone, polyarylate, polycarbonate, and polypropylene.
[21] The laminate for acoustic members according to any one of [16] to [20] above, wherein the thickness of the curable resin layer (X) is 1 μm or more and 300 μm or less.
[22] The laminate for acoustic components according to any one of [16] to [21] above, wherein the thickness of the resin layer (Y) is 1 μm or more and 200 μm or less.
[23] The laminate for acoustic members according to any one of [16] to [22] above, at least a portion of which is formed into at least one of a dome shape and a cone shape.
[24] The laminate for acoustic components according to any one of [16] to [23] above, which is molded so as to impart a tangential edge to the surface.
[25] The laminate for acoustic members according to any one of the above [16] to [24], which is used as a diaphragm for an electroacoustic transducer.
[26] The laminate for acoustic components according to the above [25], wherein the diaphragm is a speaker diaphragm.
[27] The laminate for acoustic components according to any one of [16] to [26] above, wherein the peel strength of the resin layer (Y) to the curable resin layer (X) after curing is 10 N/10 mm or less.
[28] The laminate for acoustic components according to any one of [16] to [27] above, wherein the peel strength of the resin layer (Y) to the curable resin layer (X) before curing is 0.01 N/10 mm or more.

[29] A step of heating the acoustic member laminate according to any one of [16] to [28] above, shaping the laminate in a mold, and curing the curable resin layer (X);
and peeling off the resin layer (Y) from the shaped and cured curable resin layer (X).
[30] The method for producing an acoustic member according to the above [29], wherein the heating temperature during shaping is 180°C or higher and 260°C or lower.
[31] The method for producing an acoustic member according to the above [29] or [30], wherein the shaping time is from 1 second to 5 minutes.
[32] The method for producing an acoustic member according to any one of [29] to [31] above, wherein the acoustic member laminate is shaped by any one of press molding, vacuum molding, and pressure molding.
[33] A method for using the laminate for acoustic members according to any one of [16] to [28] above in an acoustic member.
[34] Use of a laminate for acoustical members, comprising the laminate for acoustical members according to any one of [16] to [28] above.

[35] A thermoforming laminate comprising a curable resin layer (Xa) and a resin layer (Ya) laminated on both sides of the curable resin layer (Xa), wherein the resin layer (Ya) is peelable from the curable resin layer (Xa) after curing.
[36] The thermoforming laminate according to the above [35], wherein the resin layer (Ya) is directly laminated on both sides of the curable resin layer (Xa).
[37] The thermoforming laminate according to the above [35] or [36], wherein the peel strength of the resin layer (Y) to the curable resin layer (Xa) after curing is 10 N/10 mm or less.
[38] The thermoforming laminate according to any one of [35] to [37], wherein the peel strength of the resin layer (Ya) to the curable resin layer (Xa) before curing is 0.01 N/10 mm or more.
[39] The thermoforming laminate according to any one of the above [35] to [38], wherein the curable resin layer (Xa) is made of a resin component containing an organopolysiloxane (A).
[40] The thermoforming laminate according to the above [39], wherein the curable resin layer (Xa) is made of a millable resin component containing an organopolysiloxane (A).
[41] A step of heating the thermoforming laminate according to any one of the above [35] to [40] to shape it using the mold, and curing the curable resin layer (Xa);
and peeling off both of the resin layers (Y) provided on both sides from the shaped and cured curable resin layer (Xa).

According to the present invention, it is possible to provide an acoustic member having an appropriate elastic modulus and high heat resistance, toughness, and tensile yield elongation. In addition, when the acoustic member of the present invention is used as a diaphragm for an electroacoustic transducer such as a speaker diaphragm, it is expected to have excellent sound reproduction properties from low to high temperature ranges, to be less susceptible to problems such as the effect of high temperature and other usage environments on sound quality, and to be free from deformation or breakage due to long-term vibration.
Furthermore, according to the present invention, it is possible to provide a laminate for acoustic members that can produce heat-resistant acoustic members with good productivity and ease of handling.

1 is a cross-sectional view showing a structure of a micro-speaker diaphragm 1 according to an embodiment of the present invention. 4 is a cross-sectional view showing the structure of a micro-speaker diaphragm 11 according to another embodiment of the present invention. FIG. FIG. 11 is a plan view showing the structure of a micro-speaker diaphragm 21 according to another embodiment of the present invention.

Hereinafter, an embodiment of the present invention will be described, however, the present invention is not limited to the embodiment described below as long as it does not depart from the gist of the present invention.
Incidentally, since the boundary between a film and a sheet is not clearly defined, in the present invention, the film includes a sheet.

[Acoustic components]
The acoustic member of the present invention is an acoustic member made of a resin component containing organopolysiloxane (A), characterized in that the proportion of insoluble matter after immersion in chloroform for 24 hours is 50% or more. In the present invention, by making the proportion of the insoluble matter 50% or more, the total proportion of the crosslinking component and the filler mixed as necessary in the acoustic member is high. Therefore, an acoustic member having an appropriate elastic modulus and high heat resistance, toughness, and tensile yield elongation can be provided. When used in a diaphragm for an electroacoustic transducer such as a speaker diaphragm, it is expected to have excellent sound reproduction from low to high temperature ranges, and problems such as the use environment such as high temperature affecting the sound quality are unlikely to occur, and deformation or breakage due to long-term vibration is unlikely to occur.

On the other hand, if the proportion of insoluble matter in an acoustic component falls below 50%, the elastic modulus may become too low, or mechanical strength such as tensile strength may decrease, causing problems with sound quality and handling. In addition, if the component is placed in a high-temperature environment during use, crosslinking may progress, causing a significant change in sound quality.

The acoustic member of the present invention is a cured product of a resin component containing an organopolysiloxane (A). In this specification, the resin component may be composed of the organopolysiloxane (A) alone, or may be a resin composition containing a resin other than the organopolysiloxane (A), an additive other than the resin, a curing agent, or other components.
The acoustic member may be made of a single layer of film (X1). The film (X1) is a cured product of the above-mentioned resin component, that is, the acoustic member of the present invention may be made of a film (X1) that contains organopolysiloxane (A) and has an insoluble content of 50% or more after immersion in chloroform for 24 hours. The acoustic member may be made of a single layer of film (X1), which makes it suitable for use as a diaphragm or the like.

The proportion of the insoluble matter in the acoustic member (preferably film (X1)) is preferably 60% or more, more preferably 70% or more, even more preferably 75% or more, even more preferably 85% or more, particularly preferably 90% or more, and most preferably 93% or more. The proportion of the insoluble matter is preferably as close to 100% as possible, and there is no particular upper limit, so long as it is 100% or less. If the proportion of the insoluble matter in organopolysiloxane (A) is within this range, the acoustic member of the present invention has an optimal elastic modulus and is excellent in sound quality and handling. Furthermore, even when placed in a high-temperature environment during use, crosslinking does not progress much, so changes in sound quality can be kept small.

The above-mentioned proportion of insoluble matter can be measured as follows.
1) Approximately 100 mg of a sample is taken from the acoustic member, and the sample mass (a) is measured.
2) The collected sample is immersed in chloroform at 23° C. for 24 hours.
3) The solid content in the chloroform is removed and vacuum dried at 50° C. for 7 hours.
4) The mass (b) of the solid content after drying is measured.
5) Using the masses (a) and (b), calculate the proportion of insoluble matter based on the following formula (i).

As is clear from the above measurement method, the insoluble matter is the total amount of the crosslinked components of the organopolysiloxane (A) contained in the acoustic component and the insoluble matter other than the crosslinked components, such as the filler.

The acoustic member of the present invention preferably has a tensile yield elongation of 20% or more, more preferably 30% or more, even more preferably 40% or more, and particularly preferably 50% or more, and particularly preferably has no yield point. The higher the tensile yield elongation, the more preferable it is, and there is no particular upper limit. If the tensile yield elongation is equal to or greater than the above lower limit, or if there is no yield point, there is little deformation due to long-term vibration, and the effect on changes in acoustic properties tends to be small.
The tensile yield elongation refers to the elongation (%) at the yield point of the stress-strain curve obtained in a tensile test. A material that does not have a yield point until breakage is said to have no yield point.

In the acoustic member of the present invention, the ratio _E100 /E20 of the tensile storage modulus _E20 at 20°C to the tensile storage modulus _E100 at 100°C is preferably 0.5 or more and 1.2 or _less . By setting the ratio _E100 / _E20 within the above range, the change in the modulus of elasticity due to temperature change becomes small, and the heat resistance tends to be good. In addition, since the change in the modulus of elasticity in the high temperature range is small, the sound quality is less likely to deteriorate in a high temperature environment, and the sound reproduction can be improved from the low temperature range to the high temperature range.
The ratio _E100 / _E20 of the acoustic member of the present invention is preferably 0.55 or more and 1.1 or less, preferably 0.6 or more and 1 or less, more preferably 0.65 or more and 0.97 or less, and particularly preferably 0.7 or more and 0.95 or less. If _E100 / _E20 is in this range, the heat resistance tends to be excellent because the change in elastic modulus is small while maintaining moldability. Therefore, it is possible to prevent deterioration of sound quality in high-temperature environments and to easily achieve excellent sound reproduction from low to high temperature ranges.

The acoustic member of the present invention preferably has a tensile storage modulus ( _E20 ) at 20°C of 1 MPa to 800 MPa, more preferably 2 MPa to 400 MPa, even more preferably 3 MPa to 100 MPa, particularly preferably 4 MPa to 60 MPa, and particularly preferably 5 MPa to 30 MPa. If the tensile storage modulus ( _E20 ) at 20°C is within this range, the modulus is in an appropriate range, and therefore the acoustic characteristics such as sound quality and reproducibility tend to be excellent.

The acoustic member of the present invention preferably has a tensile breaking elongation of 200% or more, more preferably 250% or more, even more preferably 300% or more, particularly preferably 350% or more, and especially preferably 400% or more. The higher the tensile breaking elongation, the better, and there is no particular upper limit. If the tensile breaking elongation is within this range, the toughness of the acoustic member will be high, making it less likely to break due to long-term vibration and tending to have excellent durability.

In the acoustic member of the present invention, the Type A durometer hardness of the resin component is preferably 30 or more and 90 or less. When the Type A durometer hardness is in the above range, the elastic modulus tends to be in an appropriate range, and sound quality and handling properties tend to be good. From these viewpoints, the Type A durometer hardness is more preferably 40 or more and 85 or less, and even more preferably 50 or more and 80 or less.

The measured values of the tensile elongation at yield, the tensile elongation at break, and the tensile storage modulus may be obtained by measuring the acoustic member (for example, film (X1)) as it is, or may be obtained by measuring a film obtained by curing a resin component described later under the same molding method and curing conditions (heating temperature, pressure, and heating time) as those for the acoustic member. The type A durometer hardness can be measured based on JIS K 6253-3:2012 for a test piece having a thickness of 6 mm obtained by curing a resin component described later under the same conditions of curing temperature x heating time of 20 minutes as those for the acoustic member. The details of the method for measuring the tensile elongation at yield, the tensile elongation at break, and the tensile storage modulus are as described in the examples, and if the film has a directional property, it is recommended to measure in the TD direction (the direction perpendicular to the resin flow direction).

[Organopolysiloxane (A)]
The organopolysiloxane (A) of the present invention has a structure represented by the following formula (ii).
R _n SiO _(4-n)/2 ...(ii)
Here, R may be the same or different, and is a substituted or unsubstituted monovalent hydrocarbon group, preferably a monovalent hydrocarbon group having 1 to 12 carbon atoms, more preferably 1 to 8 carbon atoms, and n is a positive number from 1.95 to 2.05.

R can be, for example, alkyl groups such as methyl, ethyl, propyl, butyl, hexyl, and dodecyl; cycloalkyl groups such as cyclohexyl; alkenyl groups such as vinyl, allyl, butenyl, and hexenyl; aryl groups such as phenyl and tolyl; aralkyl groups such as β-phenylpropyl; and chloromethyl, trifluoropropyl, and cyanoethyl groups in which some or all of the hydrogen atoms bonded to the carbon atoms of these groups have been replaced with halogen atoms or cyano groups.

It is also preferable that the molecular chain terminals of the organopolysiloxane (A) are blocked with a trimethylsilyl group, a dimethylvinyl group, a dimethylhydroxysilyl group, a trivinylsilyl group, or the like. It is also preferable that the organopolysiloxane (A) has at least two alkenyl groups in the molecule. Specifically, it is preferable that the R has alkenyl groups in an amount of 0.001 mol % or more and 5 mol % or less, preferably 0.005 mol % or more and 3 mol % or less, more preferably 0.01 mol % or more and 1 mol % or less, and particularly 0.02 mol % or more and 0.5 mol % or less, and it is especially preferable that the organopolysiloxane has vinyl groups. The organopolysiloxane is basically a linear diorganopolysiloxane, but may be partially branched. It may also be a mixture of two or more types with different molecular structures.

In the acoustic component, the organopolysiloxane (A) is crosslinked, preferably by an organic peroxide (C). Examples of the organic peroxide (C) include di-t-butyl peroxide, 2,5-dimethyl-2,5-di(t-butylperoxy)hexane, 2,5-dimethyl-2,5-bis(t-butylperoxy)hexane, and other alkyl peroxides, and 2,4-dicumyl peroxide and other aralkyl peroxides. From the viewpoints of crosslinking speed and safety, however, alkyl peroxides, particularly 2,5-dimethyl-2,5-di(t-butylperoxy)hexane, are preferred.

The organic peroxide (C) is contained as an additive in the resin component. The content of the organic peroxide (C) in the resin component 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, even more 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 especially preferably 0.3% by mass or more and 2% by mass or less. If the content of the organic peroxide (C) is within this range, a composition having a sufficient curing speed tends to be obtained safely.

The resin component is preferably a millable type containing organopolysiloxane (A). In an uncured state, the millable type resin component is non-liquid (e.g., solid or paste-like) with no self-flowability at room temperature (25°C), but can be mixed uniformly using a kneader, which will be described later. By using a millable type resin component, the acoustic member of the present invention, as will be described later, has good productivity when processing the resin component into a curable resin layer (X) and good handleability of the laminate for acoustic members having a curable resin layer (X), and also tends to have excellent handleability when shaping the acoustic member.

The resin component of the present invention may contain a filler such as a silica-based filler. The filler constitutes a part of the insoluble portion, and therefore, by containing the filler, the resin component of the present invention has a higher ratio of insoluble portions, which makes it easier to set the mechanical properties of the acoustic component, such as the elastic modulus and tensile strength, within an appropriate range. In addition, by adding the filler, it is easy to adjust the viscosity and hardness of the resin component, that is, it is easy to optimize the balance between the fluidity and secondary processability of the resin component during processing. In addition, there is an advantage that it is easy to appropriately adjust the hardness according to the design and acoustic characteristics of the acoustic component. Examples of the silica-based filler include fumed silica and precipitated silica, and the silica-based filler may be surface-treated with a silane coupling agent.
The content of the silica-based filler is, 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, more preferably 20% by mass or more and 35% by mass or less, based on the total amount of the resin components. The average particle size of the silica-based 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, more preferably 0.5 μm or more and 5 μm or less. The average particle size of this silica-based filler can be measured as the median size (D50) using a particle size distribution measuring device using a laser light diffraction method or the like.

The resin component of the present invention may contain various additives such as heat stabilizers, antioxidants, UV absorbers, light stabilizers, antibacterial and antifungal agents, antistatic agents, lubricants, pigments, dyes, flame retardants, and impact modifiers, to the extent that the effect is not impaired.

In the present invention, commercially available organopolysiloxane (A) can be used. In addition to organopolysiloxane (A), commercially available silicone resin compositions containing additives such as silica-based fillers can also be used. Specifically, products sold by Shin-Etsu Chemical Co., Ltd. under the trade names "KE-597-U" and "KE-594-U" can also be used.

In the acoustic component, the crosslinking degree of the organopolysiloxane (A) is preferably 35% or more. By making the crosslinking degree of the organopolysiloxane (A) 35% or more, the organopolysiloxane (A) is crosslinked to a certain amount or more. Therefore, the elastic modulus becomes a more appropriate value, and it becomes easier to provide an acoustic component having high heat resistance, toughness, and tensile yield elongation. In addition, even if it is placed in a high temperature environment during use, crosslinking is unlikely to proceed, and there is a tendency that the sound quality can be prevented from changing.
From the above viewpoints, the degree of crosslinking of the organopolysiloxane (A) is more preferably 50% or more, even more preferably 60% or more, even more preferably 70% or more, particularly preferably 80% or more, and most preferably 90% or more. The higher the degree of crosslinking of the organopolysiloxane (A), the better, and it is sufficient that it is 100% or less.

The degree of crosslinking is an index showing the proportion of crosslinked components in the organopolysiloxane (A) contained in the acoustic component. The degree of crosslinking can be calculated by determining the mass (c) of the insoluble components other than the organopolysiloxane (A) contained in the sample mass (a) in the measurement of the proportion of the insoluble components, and subtracting the mass (c) from the masses (a) and (b). Specifically, the degree of crosslinking can be calculated by the following formula (iii).
The mass (c) can be determined by measuring the proportion of insoluble components other than the organopolysiloxane (A) contained in the acoustic member using a method such as NMR. Specifically, the mass (c) can be determined by, for example, identifying the chemical structure of the organopolysiloxane (A) contained in the acoustic member using a method such as solution NMR or solid-state NMR, and calculating the proportion of insoluble components other than the organopolysiloxane (A) from the area ratio of the detected peaks.

The thickness of film (X1) (i.e., the acoustic member) is preferably 1 μm or more and 300 μm or less, more preferably 5 μm or more and 200 μm or less, even more preferably 10 μm or more and 170 μm or less, particularly preferably 20 μm or more and 150 μm or less, and especially preferably 30 μm or more and 130 μm or less. If the thickness is within this range, the balance between handleability and sound quality is excellent, and furthermore, it tends to contribute to miniaturization and space saving of acoustic members such as diaphragms.

(Applications of acoustic components)
The acoustic member of the present invention has excellent heat resistance, a specific range of elastic modulus, and small change in elastic modulus from low temperature to high temperature, and is therefore suitable for use as a diaphragm among other acoustic members. As described above, the acoustic member may be made of a single layer of film (X1).
The acoustic component of the present invention can be used specifically in various electroacoustic transducers such as speakers, receivers, microphones, and earphones, and among these, it is more preferable for it to be used as a speaker diaphragm, and it can be particularly suitably used as a micro-speaker diaphragm for mobile phones and the like.

The acoustic member can be formed into various acoustic members such as a diaphragm by appropriate molding, and is preferably used as a diaphragm for an electroacoustic transducer, and particularly preferably as a speaker diaphragm.
The acoustic member may have, for example, at least a part thereof in a dome shape or a cone shape. The acoustic member may also have a tangential edge on its surface. When the acoustic member has a dome or cone shape or a tangential edge, the acoustic member is preferably used as a diaphragm for an electroacoustic transducer, more preferably as a speaker diaphragm.

(Vibration plate)
To explain the diaphragm in more detail, the shape of the diaphragm is not particularly limited and can be any shape, such as a circle, an ellipse, or an oval. The diaphragm generally has a body that vibrates in response to an electric signal or the like, and an edge surrounding the periphery of the body. The body of the diaphragm is usually supported by the edge. The shape of the diaphragm may be a dome shape or a cone shape as described above, a shape that combines these, or any other shape used for a diaphragm.

The acoustic member of the present invention may form at least a part of the diaphragm. For example, the body or edge of the diaphragm may be formed by the acoustic member of the present invention, and the edge or body of the diaphragm may be formed by another member. Of course, both the body and the edge may be integrally formed by the acoustic member of the present invention, or the entire diaphragm may be formed by the acoustic member of the present invention.

Figure 1 shows the structure of a diaphragm 1 according to one embodiment of the present invention, and is a cross-sectional view of the diaphragm 1, which is circular in plan view, cut along a plane passing through the center line of the circle. As shown in Figure 1, the diaphragm 1 has a dome portion (body) 1a at its center, a recessed portion 1b for attaching to a voice coil 2, a peripheral portion (edge) 1c, and an external attachment portion 1d on its outer periphery for attaching to a frame or the like.

Figure 2 is a diagram showing the structure of a diaphragm 11 in another embodiment of the present invention, and is a cross-sectional view of a circular diaphragm 11 in a plan view, cut along a plane passing through the center line of the circle. As shown in Figure 2, the micro speaker diaphragm 11 has a dome-shaped dome portion (body) 11a at the center, a recessed portion 11b attached to the voice coil 2, a cone portion 11j processed into a cone shape, and a peripheral portion (edge) 11c. As shown in the diaphragm 11, a portion of the diaphragm may be processed into a dome shape, and the remaining portion may be processed into a cone shape. Note that the peripheral portion 11c of the micro speaker diaphragm 11 may be directly attached to a frame or the like, or may be attached to a frame or the like via another member.

As described above, a tangential edge may be provided on the surface of the diaphragm. The tangential edge may be, for example, a groove having a V-shaped cross section. FIG. 3 shows a plan view of a diaphragm 21 according to another embodiment of the present invention. The diaphragm 21 has a tangential edge portion 21g having multiple tangential edges 21e provided on the outer periphery of a circular dome portion (body) 21a, and a tangential edge portion 21h having multiple tangential edges 21f arranged on the outer periphery of the tangential edge portion 21g. Note that FIG. 3 shows an example in which two tangential edge portions are provided along the radial direction, but the number of tangential edge portions may be only one or three or more along the radial direction.

As described above, the diaphragm is preferably a speaker diaphragm, particularly a micro speaker diaphragm. From the viewpoint of suitable use as a micro speaker diaphragm, the size of the diaphragm is such that the maximum diameter is 25 mm or less, preferably 20 mm or less, and the maximum diameter is preferably 5 mm or more. Note that the maximum diameter refers to the diameter when the diaphragm is circular, and the major diameter when the diaphragm is elliptical or oval.

The diaphragm may be formed only from the acoustic member of the present invention (preferably a single layer of film (X1)), or may be formed from a composite material of the acoustic member of the present invention and another member. For example, as described above, either the edge or the body may be formed from another member.

Furthermore, in order to improve the secondary processing suitability and dust resistance of the diaphragm, or to adjust the acoustic characteristics and improve the design, the surface of the diaphragm may be further treated as appropriate by coating it with an antistatic agent, vapor-depositing a metal, sputtering, coloring it (black, white, etc.), etc. Furthermore, it may be appropriately laminated with a metal such as aluminum, or combined with a nonwoven fabric, etc.

(Method of manufacturing acoustic components)
The acoustic component of the present invention is obtained by forming the resin component into a film, for example, and curing the organopolysiloxane (A) by heating or the like to crosslink the organopolysiloxane (A). The method for forming the resin component into a film and heating it is not particularly limited, but it is preferable to mold the film into a desired shape by shaping during heating. In addition, the acoustic component is preferably manufactured using a laminate for acoustic components, the details of which will be described later.

The method for producing the resin component is not particularly limited, but when the resin component is a mixture of multiple resins, fillers, additives, etc., it can be obtained, for example, by kneading the materials constituting the resin component. As a kneader used for kneading, a known kneader such as an extruder such as a single-screw or twin-screw extruder, a calendar roll such as a two-roller or three-roller, a roll mill, a plastomill, a Banbury mixer, a kneader, or a planetary mixer can be used. In addition, when two or more resins are mixed and used, the dispersion state of the resin component can be appropriately adjusted by selecting the type of kneader and the kneading conditions.
The kneading temperature is adjusted as appropriate depending on the type and mixing ratio of the resins, and the presence and type of additives. In order to appropriately reduce the viscosity of the resin while suppressing crosslinking to facilitate kneading, the kneading temperature is preferably 20° C. or higher and 150° C. or lower, more preferably 30° C. or higher and 140° C. or lower, even more preferably 40° C. or higher and 130° C. or lower, particularly preferably 50° C. or higher and 120° C. or lower, and especially preferably 60° C. or higher and 110° C. or lower.
The kneading time may be long enough to uniformly mix the materials constituting the resin component, and may be, for example, several minutes to several hours, and preferably 5 minutes to 1 hour.

[Laminate for acoustic components]
The above-mentioned acoustic member of the present invention is preferably produced from the laminate for acoustic members of the present invention described below.
The laminate for acoustic components of the present invention comprises a curable resin layer (X) made of a millable resin component containing an organopolysiloxane (A) and a resin layer (Y) laminated on at least one side of the curable resin layer (X), and the resin layer (Y) is peelable from the curable resin layer (X) after curing. The resin layer (Y) is preferably laminated directly on the curable resin layer (X), and is preferably laminated on both sides of the curable resin layer (X), and more preferably laminated directly on both sides of the curable resin layer (X).
In the present invention, by using the laminate for acoustic members, it is possible to produce heat-resistant acoustic members with good productivity and ease of handling.

The curable resin layer (X) is made of a millable resin component containing an organopolysiloxane (A). In the present invention, by using a millable resin component as the resin component, the productivity when processing the resin component into the curable resin layer (X) is improved. In addition, the uncured resin component is less likely to flow out during molding or transportation, and the handling properties are improved. Furthermore, since the uncured millable resin component (i.e., the curable resin layer (X)) generally has tackiness and can be adhered to the resin layer (Y) with a relatively high adhesive force, the curable resin layer (X) is less likely to peel off from the resin layer (Y) when the laminate for acoustic components is placed in a mold or during transportation, and the handling properties are also improved in this respect.
The details of the resin component are as described above. Therefore, the resin component (i.e., the curable resin layer (X)) preferably contains, in addition to the organopolysiloxane (A), an organic peroxide (C) or a filler such as a silica-based filler, and is cured to become the above-mentioned film (X1).

In addition, when the curable resin layer (X) (i.e., the film (X1)) is cured and the elastic modulus increases, the adhesive strength of the resin layer (Y) to the curable resin layer (X) decreases, and the resin layer (Y) becomes peelable from the curable resin layer (X). Therefore, in the laminate for acoustic components, the cured curable resin layer (X) can be separated from the resin layer (Y) and used appropriately as an acoustic component, for example as a single layer. Note that "peelable" means that after the curable resin layer (X) is cured, the resin layer (Y) can be peeled off from the resin layer (X) by hand, machine, etc. without destroying the resin layer (X).

The resin layer (Y) may be provided on only one side of the curable resin layer (X), but is preferably provided on both sides of the curable resin layer (X). By providing the resin layer (Y) on both sides, even if the curable resin layer (X) has tackiness, it has excellent handling properties and is easy to transport, and since the curable resin layer (X) is not exposed, it is difficult to cause poor appearance such as rubbing and scratches. In addition, when forming using a mold as described later, problems such as the curable resin layer (X) adhering to the mold are unlikely to occur. In addition, it is easy to improve the thickness accuracy and molding accuracy of the film (X1).
The resin layer (Y) provided on one or both sides of the curable resin layer (X) may be laminated directly on the curable resin layer (X), or may be laminated via another layer as long as the resin layer (Y) is peelable, but it is preferable that the resin layer (Y) is laminated directly on the curable resin layer (X). By laminating the resin layer (Y) directly on the curable resin layer (X), the structure of the laminate for acoustic components can be simplified, and further, it becomes easier to manufacture an acoustic component such as a diaphragm made of a single-layer film (X1).

In the present invention, it is preferable that the resin layer (Y) does not have any other layer such as a release layer formed by a release agent on its surface, and is laminated directly to the curable resin layer (X) without a release layer or the like. When the curable resin layer (X) is cured, the tackiness is reduced, and the adhesive strength of the resin layer (Y) to the curable resin layer (X) is reduced. As a result, the resin layer (Y) can be easily peeled off from the cured curable resin layer (X) without a release layer or the like.

When the resin layer (Y) is laminated to the curable resin layer (X) via another layer, the other layer may be, for example, a release layer.
Examples of the release agent used in the release layer include alkyd-based, olefin-based, acrylic-based, long-chain alkyl group-containing compound-based, rubber-based, melamine-based, urea-based, urea-melamine-based, cellulose-based, benzoguanamine-based, and other resins and surfactants, which may be used alone or in combination. The release agent may further contain other components such as a curing agent and a catalyst.

The thickness of the release layer is not particularly limited, and is preferably, for example, 0.02 μm or more and 2 μm or less, more preferably 0.04 μm or more and 1 μm or less, and even more preferably 0.05 μm or more and 0.5 μm or less. By setting the thickness of the release layer within the above range, it tends to be easier for the layer to fully function as a release surface.

There are no particular limitations on the method for forming the release layer. A previously formed release film or the like may be laminated with the curable resin layer (X) or resin layer (Y) by a lamination method or the like, or the release agent may be dissolved in an organic solvent or water to form a coating material, which is then applied to the curable resin layer (X) or resin layer (Y) by a normal printing method such as gravure printing, screen printing, or offset printing, and then dried and cured to form the layer.

The resin (B) constituting the resin layer (Y) is preferably a thermoplastic resin, and the glass transition temperature of the resin (B) is preferably 250°C or lower. If the glass transition temperature is 250°C or lower, the resin layer (Y) is moderately softened during shaping, and the shaping property tends to be good. From such a viewpoint, the glass transition temperature of the resin (B) is more preferably 240°C or lower, and even more preferably 230°C or lower. In addition, the glass transition temperature of the resin (B) is preferably -20°C or higher, more preferably -15°C or higher, even more preferably -10°C or higher, and particularly preferably -5°C or higher. If the glass transition temperature of the release film is equal to or higher than the lower limit, even if the temperature during shaping is sufficiently high to harden the organopolysiloxane, defects such as wrinkles due to deformation or sticking to the shaping mold are unlikely to occur.
The glass transition temperature can be measured as the peak top temperature of the tensile loss factor (tan δ) in dynamic modulus measurement according to, for example, JIS K7244-4: 1999. The dynamic modulus measurement may be carried out in the same manner as the measurement of the tensile storage modulus described above.

The thermoplastic resin constituting the resin layer (Y) is not particularly limited, and for example, a cyclic olefin resin, an amorphous polyamide, a polysulfone, a polyethersulfone, a polyphenylsulfone, a polyetherimide, a polyethylene terephthalate, a polymethylpentene, a polyetherimide sulfone, a polyarylate, a polymethylmethacrylimide, a polyetheretherketone, a polyetherketone, a polyetherketoneketone, a polycarbonate, and a polypropylene can be used. These may be used alone or in combination of two or more. When two or more types are used in combination, they may be used as a mixture, for example.
Furthermore, the resin layer (Y) may be multi-layered, or may have two or more resin layers composed of one or more of these resins. When the resin layer (Y) is provided on both sides of the curable resin layer (X), the resin layers (Y) may have different configurations from each other, but it is preferable that the resin layers (Y) have the same configuration from the viewpoint of easily suppressing curling of the laminate.

Among the above, from the viewpoints of heat resistance, formability, and peelability from the curable resin layer (X) after curing, at least one selected from polyetherimide, polyethylene terephthalate, polymethylpentene, polyetheretherketone, polysulfone, polyarylate, polycarbonate, and polypropylene is preferred. Among these, at least one selected from polyetheretherketone, polyetherimide, polymethylpentene, and polyethylene terephthalate is more preferred, and from the viewpoints of excellent heat resistance, formability, and peelability, it is even more preferred to use any one of polyetherimide, polymethylpentene, and polypropylene alone or in combination.

In addition to the resin (B), the resin layer (Y) may contain, as necessary, conventionally known inorganic particles, organic particles, antioxidants, antistatic agents, heat stabilizers, lubricants, dyes, pigments, UV absorbers, flame retardants, impact resistance modifiers, etc., within the scope of the present invention.

The thickness of the curable resin layer (X) is preferably 1 μm or more and 300 μm or less, more preferably 5 μm or more and 200 μm or less, even more preferably 10 μm or more and 170 μm or less, particularly preferably 20 μm or more and 150 μm or less, and especially preferably 30 μm or more and 130 μm or less. If the thickness is within this range, it becomes easier to manufacture an acoustic member made of a film (X1) having the above-mentioned thickness.

The thickness of the resin layer (Y) is preferably 1 μm or more and 200 μm or less, more preferably 3 μm or more and 150 μm or less, even more preferably 5 μm or more and 100 μm or less, particularly preferably 10 μm or more and 80 μm or less, and particularly preferably 15 μm or more and 60 μm or less. By making the thickness 1 μm or more, it is possible to prevent the resin layer (Y) from being damaged during shaping, and since it is made self-supporting, it tends to be easy to handle during production and has excellent handling properties when released from the mold. In addition, by making the thickness 200 μm or less, it becomes easier to properly shape the resin layer (X) into the desired shape even if the laminate for acoustic components is shaped as it is.

The laminate for acoustic components is preferably in the form of a film, and although there are no particular limitations on its overall thickness, it is preferably 2 μm or more and 700 μm or less, more preferably 8 μm or more and 500 μm or less, even more preferably 20 μm or more and 370 μm or less, particularly preferably 40 μm or more and 310 μm or less, and especially preferably 60 μm or more and 250 μm or less.

In the laminate for acoustic members, the curable resin layer (X) before curing has a relatively low elastic modulus and typically has tackiness, so that even if the peel strength with the resin layer (Y) is low, it can be moderately adhered to the resin layer (Y) and has good handleability. Therefore, the peel strength of the resin layer (Y) before curing with the curable resin layer (X) may be the same as, larger than, or smaller than the peel strength after curing described later.
The peel strength of the resin layer (Y) against the curable resin layer (X) before curing is not particularly limited, but is preferably 0.01N/10mm or more and 15N/10mm or less, more preferably 0.02N/10mm or more and 10N/10mm or less, even more preferably 0.04N/10mm or more and 5N/10mm or less, particularly preferably 0.05N/10mm or more and 3N/10mm or less, particularly preferably 0.06N/10mm or more and 1N/10mm or less, and most preferably 0.07N/10mm or more and 0.7N/10mm or less. By making the peel strength of the resin layer (Y) against the curable resin layer (X) before curing 0.01N/10mm or more, the resin layer (Y) is prevented from being accidentally peeled off from the curable resin layer (X) during transportation or molding, and the handling property is easily improved. Furthermore, by making the peel strength 15 N/10 mm or less, the peel strength of the resin layer (Y) from the curable resin layer (X) after curing can be easily reduced.

As described above, the elastic modulus of the curable resin layer (X) after curing is a certain value or more, and the peel strength of the resin layer (Y) against the cured curable resin layer (X) is reduced, so that the resin layer (Y) can be easily peeled off from the cured curable resin layer (X). On the other hand, depending on the resin type of the resin layer (Y), the elastic modulus of the curable resin layer (X) is higher than before curing by being cured, so that the peel strength of the cured resin layer (Y) against the cured curable resin layer (X) may be higher than the peel strength before curing. From such a viewpoint, the peel strength of the cured resin layer (Y) against the cured curable resin layer (X) is preferably 10N/10mm or less, more preferably 5N/10mm or less, even more preferably 3N/10mm or less, particularly preferably 2N/10mm or less, particularly preferably 1N/10mm or less, and most preferably 0.8N/10mm or less. By making the peel strength of the resin layer (Y) from the cured curable resin layer (X) 10 N/10 mm or less, the resin layer (Y) can be easily peeled from the cured curable resin layer (X), i.e., the film (X1). Therefore, even if the laminate for an acoustic component is directly shaped, an acoustic component made of the film (X1) alone can be easily produced.
Furthermore, the peel strength of the resin layer (Y) after curing with respect to the curable resin layer (X) is not particularly limited, but is preferably, for example, 0.01 N/10 mm or more, more preferably 0.03 N/10 mm or more, and even more preferably 0.05 N/10 mm or more.
The peel strength of the resin layer (Y) from the cured curable resin layer (X) refers to the peel strength after the curable resin layer (X) is cured under the curing conditions when actually manufacturing a molded product (acoustic member), and for example, refers to the peel strength when the crosslinking degree of the curable resin component in the curable resin layer (X) is 80% or more. The curing conditions for achieving a crosslinking degree of 80% or more depend on the thickness of the curable resin layer (X), but for example, in the case of a thickness of 100 μm, the acoustic member laminate can be measured after heating for about 2 to 5 minutes at a temperature of 180° C. or more. In addition, during curing, it is preferable to heat while applying pressure, for example, press heating at 0.2 MPa.
The peel strength means the peel strength when the curable resin layer (X) before or after curing is fixed and the resin layer (Y) is peeled from the fixed curable resin layer (X) at a peel angle of 180° and a peel speed of 300 mm/min. When the curable resin layer (X) has a directional property, it is preferable to measure the peel strength in the TD direction (the direction perpendicular to the resin flow direction). The peel strength is preferably measured according to a method in accordance with JIS K6854-2:1999.

The acoustic member laminate is used for acoustic members such as diaphragms, and is particularly used for the manufacture of acoustic members. The details of the acoustic members and diaphragms are as described above.
As described below, the acoustic member laminate is molded into a shape that corresponds to the shape of an acoustic member such as a diaphragm by being shaped using a mold. Therefore, it is preferable that at least a portion of the acoustic member laminate is molded into a dome shape, a cone shape, or the like. The acoustic member laminate may also be molded so that a tangential edge is provided on the surface of the acoustic member laminate.

(Method of manufacturing laminate for acoustic components)
The laminate for acoustic members can be formed by a general forming method, for example, lamination forming, extrusion forming such as co-extrusion, coating, etc. Among these, it is preferable to select lamination forming, taking into consideration the easiness of forming a multilayer structure of the curable resin layer (X) and the resin layer (Y).
In the laminate molding, the organopolysiloxane (A) and additives such as an organic peroxide (C) that is blended as necessary are added to the above-mentioned kneader and kneaded, and then the resin component is put between the resin films that are to become the resin layer (Y) that are uncured and fed from two directions. Here, the resin component may be put between the resin films by extruding it from a T-die or the like using an extruder or the like. Thereafter, the thickness is adjusted in the gap between the rolls as necessary, and an acoustic component laminate in which an uncured curable resin layer (X) is formed between the resin layers (Y) is obtained. The laminate molding may be performed by roll-to-roll. Alternatively, one of the resin films may be omitted to obtain an acoustic component laminate consisting of a curable resin layer (X) and a resin layer (Y).
In extrusion molding, for example, a laminate for acoustic components can be produced by co-extrusion of a resin component for forming the curable resin layer (X) and a resin (B) for forming the resin layer (Y).

In the laminate molding, instead of the resin film to be the resin layer (Y), a process film having high peelability against the uncured resin component may be prepared, and a laminate having a curable resin layer (X) formed between two process films may be obtained. In this case, the two process films may be peeled off from the obtained laminate, and instead of the process film, a resin film to be the resin layer (Y) may be attached to the curable resin layer (X) to obtain an acoustic member laminate having an uncured curable resin layer (X) formed between the resin layers (Y).
In addition, after forming a curable resin layer (X) between one process film and a resin film that will become the resin layer (Y), the process film may be peeled off and the resin film that will become the resin layer (Y) may be bonded to the curable resin layer (X) instead of the process film, thereby obtaining an acoustic component laminate in which an uncured curable resin layer (X) is formed between the resin layers (Y).
The processing film may be a resin film, or a release film whose surface is treated with a release agent. Examples of the resin film used as the processing film include a polyethylene terephthalate film, a polypropylene film, and a polymethylpentene film.

In other molding methods such as extrusion molding other than lamination molding, a laminate consisting of a process film and a curable resin layer (X) can be obtained in the same manner, the process film can be peeled off from the laminate, and a resin film that will become the resin layer (Y) can be attached to the curable resin layer (X) in place of the release film to obtain an acoustic member laminate.

Even when a processing film is used, an acoustic component laminate may be manufactured in which a resin layer (Y) is laminated on only one side of a curable resin layer (X). For example, after forming a curable resin layer (X) between one processing film and a resin film that will become the resin layer (Y), the processing film may be peeled off to obtain an acoustic component laminate in which a resin layer (Y) is laminated on only one side of the curable resin layer (X).

[Method of manufacturing an acoustic component using a laminate for an acoustic component]
The laminate for acoustic components of the present invention is used for acoustic components as described above, and more specifically, is used for manufacturing acoustic components. A method for manufacturing an acoustic component using the laminate for acoustic components includes the following steps 1 and 2.
Step 1: A step of heating the acoustic member laminate to form a shape using a mold and curing the curable resin layer (X). Step 2: A step of peeling the resin layer (Y) from the shaped and cured curable resin layer (X) (i.e., the film (X1)).

Each step will now be described in more detail.
(Step 1)
In step 1, the acoustic laminate is heated and shaped in a mold, and the curable resin layer (X) is cured, thereby forming the acoustic laminate into a desired shape. The shaping method in step 1 is not particularly limited, and may be performed by any of a vacuum forming method, a pressure forming method, a press forming method, etc., among which press forming is preferred because it is easier to form.
A mold may be prepared according to the molding method, and the mold may have projections and recesses corresponding to the shape of the acoustic member to be manufactured. A metal die is typically used as the mold, but a resin mold may also be used. For example, if the acoustic member has at least one of a dome shape and a cone shape, the mold may have projections and recesses corresponding to the dome shape or the cone shape. In addition, if the acoustic member has a tangential edge on the surface, the mold may have projections and recesses corresponding to the tangential edge.

In step 1, the heated acoustic member laminate may be shaped using a mold. For example, the acoustic member laminate placed on the mold may be shaped using the mold while being heated, or a preheated acoustic member laminate may be placed on the mold and then shaped using the mold, or a combination of these may be used. The acoustic member laminate may be heated by any method. For example, when heating the acoustic member laminate placed on the mold, the mold may be heated and the laminate may be heated by heat transfer, or another method may be used.

The heating temperature during shaping 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. If the temperature during shaping is within this range, the resin layer (Y) tends to be able to cure at a sufficient speed without melting or deforming due to heat.

The shaping time is preferably 1 second to 5 minutes, more preferably 5 seconds to 4 minutes, even more preferably 10 seconds to 3 minutes, and particularly preferably 20 seconds to 2 minutes. If the heat treatment time during shaping is within this range, it tends to be easy to sufficiently harden the composition while maintaining productivity.
The curable resin layer (X) is preferably cured while being shaped, but may be cured after shaping without any particular limitation. The shaping time refers to the time during which the acoustic member laminate is shaped and cured in the mold, and does not include the time for moving the mold before the start of shaping and after the end of shaping, or the time for releasing the laminate from the mold.

(Step 2)
In step 2, the resin layer (Y) is peeled off from the curable resin layer (X) (film (X1)) shaped and cured in step 1. In step (2), the resin layer (Y) is peeled off to obtain an acoustic member consisting of the film (X1) alone and having a desired shape. In step (2), the curable resin layer (X) is cured, so that the resin layer (Y) can be easily peeled off from the cured curable resin layer (X) as described above. In step 2, when the resin layer (Y) is provided on both sides of the curable resin layer (X), both resin layers (Y) are peeled off from the cured curable resin layer (X) (film (X1)).

According to the above-mentioned manufacturing method, it is possible to manufacture a molded acoustic component with high molding accuracy and thickness accuracy even if the thickness is thin. In addition, it can be cured in a short time, the molding cycle is short, and the productivity is good. In addition, the mold is simple and it can be used for various shapes.
Furthermore, if the resin component is shaped after being cured, there is a concern that the resin will undergo elastic recovery and return to its original shape. However, by using the above-described production method, organopolysiloxane (A) is shaped while being cured, or is cured after being shaped, acoustic components such as diaphragms having complex shapes can be stably produced.

[Thermoforming laminate]
In another aspect, the present invention provides a thermoforming laminate, the thermoforming laminate comprising a curable resin layer (Xa) and resin layers (Ya) directly laminated on both sides of the curable resin layer (Xa), the resin layers (Ya) being peelable from the curable resin layer (Xa) after curing.
The resin constituting the curable resin layer (Xa) may be a thermosetting resin such as an epoxy resin, a urethane resin, a silicone resin, an acrylic resin, a phenolic resin, an unsaturated polyester resin, a polyimide resin, or a melamine resin. Of these, it is preferable to use a silicone resin.

When using a silicone resin, the silicone resin may be the organopolysiloxane (A) as described above, and the curable resin layer (Xa) may be made of a millable resin component containing the organopolysiloxane (A). That is, in a preferred embodiment of the thermoforming laminate, the curable resin layer (Xa) is the same as the curable resin layer (X) described above. The structure of the resin layer (Ya) in the thermoforming laminate may also be the same as the resin layer (Y) in the acoustic member laminate described above.
Therefore, the preferred embodiment of the thermoforming laminate is the same as that of the acoustic member laminate described above. That is, the thickness of the curable resin layer (Xa), the thickness of the resin layer (Ya), the thickness of the thermoforming laminate, the peel strength of the resin layer (Ya) to the curable resin layer (Xa) before and after curing, and the like are the same as the thickness of the curable resin layer (X), the thickness of the resin layer (Y), and the peel strength of the resin layer (Y) to the curable resin layer (X) before and after curing described in the acoustic member laminate, and the description thereof will be omitted.

The thermoforming laminate can also be used to manufacture molded products other than acoustic components, for example, packing, insulating sheets, process films, belt base materials, and other various molded products that can be manufactured by thermoforming. Thermoforming can be performed, for example, by using a mold to heat and harden the thermoforming laminate while shaping it or hardening it after shaping it, and the molding method can be vacuum molding, compressed air molding, press molding, etc., as described below.

The thermoforming laminate of the present invention is used for various molded articles as described above, and more specifically, is used for producing various molded articles. The method for producing a molded article using the thermoforming laminate includes the following steps 1a and 2a.
Step 1a: A step of heating the thermoforming laminate, shaping it with a mold, and curing the curable resin layer (Xa); Step 2a: A step of peeling off the resin layer (Ya) from the shaped and cured curable resin layer (Xa) (i.e., the film (Xa1));

(Step 1a)
In step 1a, the thermoforming laminate is heated and shaped in a mold, and the curable resin layer (Xa) is cured, thereby forming the thermoforming laminate into a desired shape. The shaping in step 1a is not particularly limited, and may be performed by any of a forming method such as vacuum forming, pressure forming, and press forming, among which press forming is preferred because it is easier to form.
The mold may be prepared according to the molding method, and may have projections and recesses according to the shape of the molded product to be manufactured. The mold may be a metal mold or a resin mold.
The details of a preferred embodiment of step 1a are the same as those of step 1 described above, and therefore the description thereof will be omitted.

(Step 2a)
In step 2a, the resin layer (Ya) is peeled off from the curable resin layer (Xa) (film (Xa1)) shaped and cured in step 1a. In step 2, the resin layers (Ya) on both sides of the curable resin layer (Xa) are peeled off from the cured curable resin layer (Xa). In step 2a, by peeling off the resin layer (Ya), a molded product consisting of the film (Xa1) alone and having a desired shape is obtained. In step 2a, by curing the curable resin layer (Xa) in step 1a, the resin layer (Ya) can be easily peeled off from the film (Xa1).
The film (Xa1) is a cured product of the above-mentioned curable resin layer (Xa), and is preferably the above-mentioned film (X1).

According to the above-mentioned manufacturing method, various molded products can be manufactured with high molding accuracy and thickness accuracy even if they are thin. In addition, the curing time is short, which is good productivity, and the mold is simple and can be used for various shapes.
In addition, when the curable resin layer (Xa) is shaped after being cured, there is a concern that the resin may elastically recover and return to its original shape. However, according to the above-described manufacturing method, the thermosetting resin is shaped while being thermally cured by crosslinking or the like, or is thermally cured after being shaped, so that molded articles having complex shapes can be stably manufactured.

The present invention will be described in detail below with reference to examples, but the present invention is not limited thereto.

Example 1
100 parts by mass of millable silicone resin composition (A)-1 (product name "KE-597-U", manufactured by Shin-Etsu Chemical Co., Ltd., silica 27% by mass, type A durometer hardness 70) containing organopolysiloxane and silica, and 1 part by mass of organic peroxide (C)-1 (product name "C-8B", manufactured by Shin-Etsu Chemical Co., Ltd., 2,5-dimethyl-2,5-di(t-butylperoxy)hexane, containing about 40% by mass) were kneaded using a planetary mixer at a temperature of 90°C for 10 minutes to obtain a resin component. The resin component was millable type. The resin component thus prepared was introduced between two polyetherimide films (product name "Superio UT (E type)", manufactured by Mitsubishi Chemical Corporation, thickness 50 μm, glass transition temperature of polyetherimide 220° C.) to be the resin layer (Y) supplied along two calendar rolls having a diameter of 100 mm, and a bank was formed on the rolls at room temperature of 25° C. and a roll temperature of 90° C., so that the thickness of the curable resin layer (X) was 100 μm, thereby obtaining a laminate consisting of resin layer (Y)/curable resin layer (X)/resin layer (Y).
The laminate was press-molded from two flat plates at a pressure of 0.2 MPa while heating at 220° C. for 2 minutes, assuming a molded shape. The curable resin layer (X) was cured by a simple method, and then both resin layers (Y) were peeled off to obtain a film (X1). The thickness of the film (X1) was 95 μm. When the peel strength of the obtained laminate was measured, the peel strength of the resin layer (Y) against the curable resin layer (X) before curing was 0.1 N/10 mm, and the peel strength of the resin layer (Y) against the curable resin layer (X) after curing was 0.3 N/10 mm. In each example, the peel strength was measured in the direction perpendicular to the extrusion direction of the film (TD direction) according to the method described in the specification.

Examples 2 to 4
A film (X1) was obtained in the same manner as in Example 1, except that the heating temperature and heating time for curing the curable resin layer (X) were changed as shown in Table 1.
The peel strength in the TD direction of the obtained laminate was measured. In all Examples, the peel strength of the resin layer (Y) from the curable resin layer (X) before curing was 0.1 N/10 mm, and the peel strength of the resin layer (Y) from the curable resin layer (X) after curing was 0.2 N/10 mm.

Example 5
The amount of organic peroxide (C)-1 used in preparing the resin component was changed to 0.05 parts by mass, and the heating temperature and heating time used in curing the curable resin layer (X) were changed as shown in Table 1. The same procedure as in Example 1 was repeated to obtain a film (X1).
The peel strength in the TD direction of the obtained laminate was measured. The peel strength of the resin layer (Y) from the curable resin layer (X) before curing was 0.1 N/10 mm, and the peel strength of the resin layer (Y) from the curable resin layer (X) after curing was 0.2 N/10 mm.

Comparative Example 1
Polyetherimide ((N)-1) was charged into a single-screw extruder equipped with a φ40 mm screw, melted while kneading at a temperature of 380° C. and a rotation speed of 30 rpm, and extruded using a T-die at an extrusion temperature of 380° C. The extruded resin was taken up by a cast roll at 230° C. to prepare an unstretched film having a thickness of 100 μm, which was evaluated as film (X1).

Comparative Example 2
Polyether ether ketone ((N)-2) was charged into a single-screw extruder equipped with a φ40 mm screw, melted while kneading at a temperature of 380° C. and a rotation speed of 30 rpm, and extruded using a T-die at an extrusion temperature of 380° C. The extruded resin was taken up by a cast roll at 230° C. to prepare an unstretched film having a thickness of 100 μm, which was evaluated as film (X1).

[Evaluation and measurement methods]
The films (X1) in the above Examples and Comparative Examples were evaluated and measured for various items as follows.

(1) Proportion of insoluble matter and degree of crosslinking According to the method described in the specification, the proportion of insoluble matter in the film (X1) and the degree of crosslinking of the organopolysiloxane (A) were measured.

(2) Tensile Yield Elongation The tensile elongation was measured in a direction perpendicular to the extrusion direction of the film (TD direction) at a tensile speed of 100 mm/min and at 23° C. according to a method in accordance with JIS K7161:2014.

(3) Tensile storage modulus A test piece of 5 mm x 8 cm (thickness 95 μm) was cut out from the film (X1) obtained in each Example and Comparative Example to obtain a measurement sample. The measurement sample was used to measure the tensile storage modulus (E 20 , E 100 ) at 20°C and 100°C using a viscoelasticity spectrometer "DVA- ₂₀₀ (manufactured by IT Measurement and Control Co., Ltd.)" in accordance with JIS K7244-4:1999, with a frequency of 10 Hz, a strain of _0.1 %, a temperature range of 20 to 400°C, and a heating rate of 3°C/min. The measurement was performed in the TD direction.

(4) Ratio of tensile storage modulus at 20°C ( _E20 ) to tensile storage modulus at 100°C ( _E100 ) ( _E100 / _E20 )
E ₁₀₀ /E ₂₀ was calculated from the respective values obtained by the measurement in (3).

(5) Tensile Elongation at Break A tensile test similar to that for the tensile yield elongation was carried out to measure the elongation at break of the film (X1).

The evaluation and measurement results for Examples 1 to 5 and Comparative Examples 1 and 2 are summarized in Table 1 below.

The films (X1) of Examples 1 to 5 above used organopolysiloxane (A) and had a ratio of insoluble matter of 50% or more, and thus had high tensile yield elongation, high tensile elongation at break, and excellent toughness. In addition, the tensile storage modulus at 20°C was in an appropriate range, and it is estimated that the acoustic properties such as sound quality and reproducibility were excellent. Furthermore, the ratio of the tensile storage modulus (E ₁₀₀ /E ₂₀ ) was in an appropriate range, and the change in modulus was small, and the heat resistance was also excellent. Therefore, when the acoustic member made of the film (X1) of each Example is used as a diaphragm for an electroacoustic transducer such as a speaker diaphragm, it is expected that the acoustic member has excellent sound reproducibility from low to high temperature ranges, and is unlikely to cause problems such as the effect of the use environment such as high temperature on sound quality, and is also unlikely to deform or break due to long-term vibration.

In contrast, in Comparative Examples 1 and 2, the tensile elongation at yield was low, the tensile elongation at break was low, and the toughness was poor. In addition, the elastic modulus of the film (X1) was high. Therefore, for example, when used as a diaphragm for an electroacoustic transducer, it is presumed that the sound quality and reproducibility are poor and deformation and breakage due to long-term vibration are likely to occur.

In addition, in each embodiment, a laminate is used that has a curable resin layer (X) made of a millable type resin component and a resin layer (Y) that is directly laminated to the curable resin layer (X), and the resin layer (Y) can be peeled off from the curable resin layer (X) after curing, so that a heat-resistant film (X1) can be produced with good productivity and handleability.

Considering the above results, it is believed that the same effects as the above examples can be obtained in the following embodiments:

(Examples 1 to 5)
A laminate produced in the same manner as in Examples 1 to 5, except that a polymethylpentene film (product name: "Opulent X44B", manufactured by Mitsui Chemicals, Inc., thickness 50 μm, glass transition temperature of polymethylpentene 42° C.) was used as the resin layer (Y).

(Examples 6 to 10)
A laminate produced in the same manner as in Examples 1 to 5, except that a polyether ether ketone film (product name: "Superio UT (KN type)", manufactured by Mitsubishi Chemical Corporation, thickness 20 μm, glass transition temperature of polyether ether ketone 154° C.) was used as the resin layer (Y).

Claims (15)

An acoustic component comprising a resin component, the proportion of insoluble matter after immersion in chloroform for 24 hours being 50% or more, the resin component being comprised of organopolysiloxane (A) or a silicone resin composition comprising organopolysiloxane (A) and an additive added thereto,
1. An acoustic component, characterized in that the organopolysiloxane (A) has a degree of crosslinking of 60% or more . The acoustic member according to claim 1, which is made of a film (X1) containing organopolysiloxane (A) and having an insoluble content of 50% or more after immersion in chloroform for 24 hours. The acoustic member according to claim 2, which consists of a single layer of the film (X1). The acoustic member according to any one of claims 1 to 3 , wherein the organopolysiloxane (A) contains an organopolysiloxane having at least two alkenyl groups in the molecule and is crosslinked. An acoustic member according to any one of claims 1 to 4, having a tensile yield elongation of 20% or more. An acoustic member according to any one of claims 1 to 4, which does not have a yield point. 7. The acoustic member according to claim 1, wherein the ratio (E ₁₀₀ /E ₂₀ ) of the tensile storage modulus (E ₂₀ ) at 20° C. to the tensile storage modulus (E ₁₀₀ ) at 100° C. is 0.5 or more and 1.2 or less. An acoustic member according to any one of claims 1 to 7, having a tensile storage modulus (E ₂₀ ) at 20°C of 800 MPa or less. An acoustic member according to any one of claims 1 to 8, having a tensile elongation at break of 200% or more. The acoustic member according to any one of claims 1 to 9, wherein the resin component is a millable type containing organopolysiloxane (A). The acoustic member according to any one of claims 1 to 10, wherein the resin component has a type A durometer hardness of 30 or more and 90 or less. An acoustic member according to any one of claims 1 to 11, having at least one of a dome shape and a cone shape. An acoustic member according to any one of claims 1 to 12, having a tangential edge on its surface. The acoustic member according to any one of claims 1 to 13, which is a diaphragm for an electroacoustic transducer. The acoustic component according to any one of claims 1 to 14, which is a speaker diaphragm.