Resin composition for acoustic components, film for acoustic components, laminate, and diaphragm for acoustic components

Abstract

To provide a resin composition for an acoustic member, which has an elastic modulus in an appropriate range, which is small in the change in elastic modulus accompanying the change in temperature, and which is high in heat resistance.SOLUTION: A resin composition for an acoustic member has a tensile storage modulus (E20) of 1100 MPa or less at 20°C, in which the ratio (E100 / E20) of a tensile storage modulus (E100) at 100°C to the tensile storage modulus (E20) at 20°C is 0.5 or larger and 1.2 or smaller.SELECTED DRAWING: None

Description

[Technical field]

[0001] The present invention relates to a resin composition for acoustic components, a film for acoustic components, a laminate including the film for acoustic components, and a diaphragm for acoustic components formed from the film for acoustic components and the laminate, and in particular to a resin composition for acoustic components, a film for acoustic components, a laminate, and a diaphragm for acoustic components that can be suitably used as a diaphragm for electro-acoustic transducers, in particular a speaker diaphragm. [Background technology]

[0002] 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.

[0003] In general, diaphragms used in electroacoustic transducers, particularly speaker diaphragms, are required to have a low density to maintain the acoustic radiation sound pressure level, a high rigidity to suppress distortion and maintain a large allowable input, an elastic modulus within a specific range to widen the reproduction frequency band, a large internal loss to suppress the divided vibration of the diaphragm and flatten the frequency characteristics, etc. Furthermore, when used near the voice coil, which is the driving source of the speaker, or in a car speaker, the diaphragm is exposed to high temperatures for a long period of time, so it is necessary for the diaphragm to have heat resistance sufficient to withstand such conditions of use.

[0004] For such electroacoustic transducer diaphragms, cyclic olefin resins, polyether ether ketone resins, polyamide resins, polyetherimide resins, and the like, which have excellent acoustic properties, have been considered in the past. For example, Patent Document 1 and Patent Document 2 disclose diaphragms mainly composed of cyclic olefin resins, and state that they have excellent acoustic properties. In addition, Patent Document 3 discloses a method for producing a polyether ether ketone resin film for diaphragms, which can improve the uniformity of the sound quality of the diaphragm. Patent Document 4 discloses a method for producing a polyamide resin film for speaker diaphragms, which can provide excellent moisture resistance, water resistance, heat resistance, light weight, moldability, and sound quality characteristics.

[0005] On the other hand, in recent years, with the miniaturization of electroacoustic transducers, especially speakers, associated with the high functionality and high performance of small electronic devices, there is a demand for materials with good reproduction in a wider range of sounds, especially in low tones, that is, materials with a relatively low elastic modulus. Furthermore, as the output power increases, the operating environment temperature becomes higher, so there is a demand for materials with little change in sound quality from low to high temperatures, that is, materials with less change in elastic modulus from low to high temperatures. [Prior art documents] [Patent documents]

[0006] [Patent Document 1] Japanese Patent Application Publication No. 6-225383 [Patent Document 2] JP 2011-176621 A [Patent Document 3] JP 2018-062153 A [Patent Document 4] JP 2016-167757 A Summary of the Invention [Problem to be solved by the invention]

[0007] However, the diaphragm described in Patent Document 1 uses a cyclic olefin resin alone or with the addition of 4-methylpentene resin or various fillers, and there are concerns about its high elastic modulus. In fact, all of the elastic modulus values ​​described in the examples exceed 2000 MPa, which is not suitable for sound reproduction, especially low-pitched sound reproduction, and does not meet the characteristics required for recent diaphragms.

[0008] In addition, the diaphragm described in Patent Document 2 uses a blend of cyclic olefin resin and polypropylene as an olefin resin, and there is concern about the high elastic modulus. Furthermore, the inventor's investigation revealed that the interface between the cyclic olefin resin and polypropylene is weak, which also causes problems with durability.

[0009] Furthermore, the inventors' investigations have revealed that the diaphragms described in Patent Documents 3 and 4 have a high elastic modulus, which causes problems with sound reproduction, especially in low-frequency sounds. In addition, the diaphragms have a high water absorption rate, which causes problems such as changes in the environmental humidity when the diaphragm is in use and water absorption over time that affects the sound quality.

[0010] The present invention has been made under these circumstances, and aims to provide a resin composition for acoustic components which has an elastic modulus within an appropriate range, little change in elastic modulus due to temperature change, and high heat resistance. [Means for solving the problem]

[0011] As a result of extensive investigations, the present inventors have succeeded in finding a resin composition capable of solving the above-mentioned problems of the conventional techniques, and have thus completed the present invention.

[0012] That is, the present invention provides the following [1] to

[29] . [1] Tensile storage modulus at 20°C (E 20 ) is 1100MPa or less, and the tensile storage modulus (E 20 ) and tensile storage modulus at 100°C (E 100 ) and the ratio (E 100 / E 20) is 0.5 or more and 1.2 or less. [2] The tensile storage modulus at 20 ° C (E 20 ) and tensile storage modulus at 100°C (E 100 ) ratio (E 100 / E 20 ) is 0.5 or more and 1 or less. [3] Tensile storage modulus at 20°C (E 20 Resin (a) having a tensile storage modulus at 20°C (E 20 The resin composition for acoustic components according to the above [1] or [2], further comprising a resin (b) having a modulus of elasticity of 50 MPa or less. [4] The tensile storage modulus (E 20 ) and tensile storage modulus at 100°C (E 100 ) ratio (E 100 / E 20 ) is 0.1 or more and 1.1 or less. [5] The tensile storage modulus (E 20 ) and tensile storage modulus at 100°C (E 100 ) ratio (E 100 / E 20 ) is 0.5 or more and 1 or less. [6] The resin composition for acoustic components according to any one of the above [3] to [5], wherein the glass transition temperature of the resin (a) is 140° C. or higher and 200° C. or lower. [7] The resin composition for acoustic components according to any one of the above [3] to [6], wherein the resin (b) has a mass average molecular weight of 50,000 or more and 300,000 or less. [8] The resin composition for acoustic components according to any one of the above [3] to [7], wherein the resin (a) is a cyclic olefin resin (A). [9] The resin composition for acoustic members according to any one of the above [3] to [8], wherein the resin (b) is a styrene-based copolymer (B).

[0013]

[10] A resin composition for acoustic components, comprising a cyclic olefin resin (A) and a styrene copolymer (B).

[11] Tensile storage modulus at 20°C (E 20 The resin composition for acoustic components according to the above

[10] , wherein the compressive strength is 1 MPa or more and 1100 MPa or less.

[12] Tensile storage modulus at 100°C (E 100 The resin composition for acoustic components according to the above

[10] or

[11] , wherein the compressive strength is 1 MPa or more and 1100 MPa or less.

[13] Tensile storage modulus at 20°C (E 20 ) and tensile storage modulus at 100°C (E 100 ) and the ratio (E 100 / E 20 ) is 0.5 or more and 1.2 or less.

[14] The resin composition for acoustic components according to any one of the above

[10] to

[13] , wherein the glass transition temperature of the cyclic olefin resin (A) is 140°C or higher and 200°C or lower.

[15] The resin composition for acoustic components according to any one of the above

[10] to

[14] , wherein the styrene-based copolymer (B) has a mass average molecular weight of 50,000 or more and 300,000 or less.

[0014]

[16] The resin composition for acoustic components according to any one of the above [8] to

[15] , wherein the cyclic olefin resin (A) contains at least a polycyclic olefin as a polymerization component.

[17] The resin composition for acoustic components according to any one of the above [9] to

[16] , wherein the styrene-based copolymer (B) is a copolymer of styrene and at least one soft segment selected from the group consisting of butadiene, isoprene, ethylene, butylene, propylene, and isobutylene.

[18] The resin composition for acoustic components according to any one of the above [9] to

[17] , wherein the proportion of the styrene component contained in the styrene-based copolymer (B) is from 1% by mass to 30% by mass.

[19] The resin composition for acoustic components according to any one of the above [9] to

[18] , wherein the styrene-based copolymer (B) is a styrene-isobutylene-styrene triblock copolymer or a styrene-isobutylene diblock copolymer.

[20] The resin composition for acoustic components according to any one of the above [1] to

[19] , which has a water absorption rate of 0.1% or less when immersed at 23°C for 24 hours.

[0015]

[21] A film for acoustic components, comprising the resin composition according to any one of [1] to

[20] above.

[22] The film for acoustic components described in

[21] above, at least a portion of which is processed into at least one of a dome shape and a cone shape.

[23] A film for acoustic components according to either

[21] or

[22] above, which has a tangential edge on its surface.

[24] The film for acoustic members according to any one of the above

[21] to

[23] , which is used for a diaphragm for an electroacoustic transducer.

[25] A laminate comprising a film for acoustic members according to any one of the above

[21] to

[24] and an adhesive layer provided on at least one surface of the film for acoustic members.

[26] A diaphragm for acoustic members obtained by molding the film for acoustic members according to any one of the above

[21] to

[24] or the laminate according to the above

[25] .

[27] The diaphragm for acoustic components according to

[26] above, which is a speaker diaphragm.

[28] A method of using the film for acoustic members according to any one of the above

[21] to

[24] or the laminate according to the above

[25] as an acoustic member.

[29] Use of the film for acoustic materials according to any one of

[21] to

[24] above, or the laminate according to

[25] above, as an acoustic material. Effect of the Invention

[0016] According to the present invention, it is possible to provide a resin composition for acoustic components having an appropriate elastic modulus, small change in elastic modulus with temperature change, and excellent heat resistance. In addition, it is expected that a diaphragm for an electroacoustic transducer, such as a speaker diaphragm, using a film for acoustic components made of the resin composition of the present invention has excellent sound reproduction from low to high temperature ranges, and is less susceptible to problems such as the sound quality being affected by the use environment, such as high temperature. [Brief description of the drawings]

[0017] [Figure 1] 1 is a cross-sectional view showing the structure of a micro-speaker diaphragm 1 according to one embodiment of the present invention. [Diagram 2] 10 is a cross-sectional view showing the structure of a micro-speaker diaphragm 11 according to another embodiment of the present invention. [Diagram 3] 11 is a plan view showing the structure of a micro-speaker diaphragm 21 according to another embodiment of the present invention. FIG. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0018] [Resin composition for acoustic components] <First aspect> First, a resin composition for acoustic components according to a first aspect of the present invention (hereinafter, the resin composition for acoustic components may be abbreviated to "resin composition") will be described in detail. The resin composition according to the first aspect has a tensile storage modulus (E 20 ) is 1100MPa or less, and the tensile storage modulus (E 20 ) and tensile storage modulus at 100°C (E 100 ) and the ratio (E 100 / E 20 ) is greater than or equal to 0.5 and less than or equal to 1.2. In the present invention, the elastic modulus is in an appropriate range and the change in elastic modulus due to temperature change is small, so that the heat resistance is excellent. In addition, since the change in elastic modulus due to temperature change is small, the change in sound quality from low to high temperature ranges is small, so that the sound reproduction is excellent and it is expected that the deterioration of sound quality in high temperature environments will not occur easily.

[0019] As described above, the resin composition according to the first aspect of the present invention has a tensile storage modulus at 20° C. (E 20 The tensile storage modulus (E 20 ) exceeds 1100 MPa, when used in acoustic components, particularly diaphragms for electroacoustic transducers which have become increasingly miniaturized in recent years, problems may arise in sound reproduction, particularly in low-pitched sounds. Tensile storage modulus at 20℃ (E 20 ) is preferably 1 MPa or more and 1100 MPa or less, more preferably 10 MPa or more and 1050 MPa or less, even more preferably 100 MPa or more and 1000 MPa or less, particularly preferably 200 MPa or more and 900 MPa or less, and particularly preferably 300 MPa or more and 800 MPa or less. When the tensile storage modulus at 20°C is within the above range, excellent acoustic characteristics can be easily obtained even when the material is used for an acoustic component, particularly a diaphragm for a miniaturized electroacoustic transducer, while maintaining the handleability during molding.

[0020] The tensile storage modulus refers to a value obtained from dynamic modulus measurement according to JIS K7244-4:1999, and is described in detail in the Examples. The same applies to the tensile storage modulus described below. In addition, a test piece for obtaining the tensile storage modulus may be prepared by, for example, press molding, extrusion molding, or the like, from a resin composition or a resin alone, and the film may be used as the test piece. In the case of extrusion molding, it is preferable to prepare the film without stretching, but since there is directionality, it is preferable to measure in MD (extrusion direction) and TD (direction perpendicular to MD in the film plane) and obtain an average value. In the case of press molding, where there is no directionality, measurement is performed in only one direction, and the measured value is used as the tensile storage modulus.

[0021] In addition, the resin composition according to the first aspect of the present invention has a tensile storage modulus at 100° C. (E 100) is preferably 1 MPa or more and 1100 MPa or less, more preferably 10 MPa or more and 1050 MPa or less, even more preferably 100 MPa or more and 1000 MPa or less, particularly preferably 150 MPa or more and 900 MPa or less, and particularly preferably 200 MPa or more and 800 MPa or less. If the tensile storage modulus of the resin composition at 100°C is within this range, it is likely to have excellent heat resistance while maintaining handleability during molding. In addition, since the change in modulus of elasticity at high temperatures is small, it is expected that excellent acoustic properties will be obtained even in high-temperature environments.

[0022] The resin composition according to the first aspect of the present invention has a tensile storage modulus E 20 and tensile storage modulus E at 100°C 100 Ratio of E 100 / E 20 is 0.5 or more and 1.2 or less. 100 / E 20 If it is smaller than 0.5 or larger than 1.2, the change in elastic modulus with temperature increases, and heat resistance decreases. In addition, because the change in elastic modulus is large in the high temperature range, sound quality is likely to decrease in high temperature environments, and it becomes difficult to achieve excellent sound reproduction from low to high temperature ranges. The ratio E of the resin composition for acoustic components according to the first aspect of the present invention 100 / E 20 is preferably 0.55 or more and 1.1 or less, more preferably 0.6 or more and 1 or less, further preferably 0.65 or more and 0.97 or less, and particularly preferably 0.7 or more and 0.95 or less. 100 / E 20 Within this range, the moldability is maintained while the change in elastic modulus is small, resulting in excellent heat resistance. This prevents deterioration of sound quality in high-temperature environments and makes it easier to achieve excellent sound reproduction from low to high temperature ranges.

[0023] The water absorption rate of the resin composition according to the first embodiment when immersed at 23°C for 24 hours is preferably 0.1% or less. If the water absorption rate is within this range, the effect of water absorption on sound quality can be reduced. Moreover, the water absorption rate according to the first embodiment is more preferably 0.07% or less, further preferably 0.05% or less, and particularly preferably 0.03% or less. The water absorption rate can be measured, for example, in accordance with JIS K7209:2000, by preparing a film from the resin composition as shown in the examples and using the film as a test piece.

[0024] [Resin (a), (b)] The resin composition according to the first aspect has a tensile storage modulus (E 20 Resin (a) having a tensile storage modulus at 20°C (E 20 It is preferable that the resin (a) contains a resin (b) having a tensile storage modulus of 50 MPa or less. By using resins (a) and (b) having different tensile storage moduli in this way, it is possible to maintain the elastic modulus of the entire resin composition within the above range while increasing the folding strength of a molded product such as a film made of the resin composition, thereby making it easier to improve impact resistance, and thus making it less likely to crack or break when used as an acoustic component.

[0025] Tensile storage modulus of resin (a) (E 20 From the above viewpoints, the compressive strength is more preferably 2150 MPa or more, further preferably 2300 MPa or more, and is preferably 5000 MPa or less, more preferably 4000 MPa or less, further preferably 3000 MPa or less. In addition, the tensile storage modulus of resin (b) (E 20 From the above viewpoints, the pressure is more preferably 30 MPa or less, even more preferably 15 MPa or less, particularly preferably 10 MPa or less, and particularly preferably 5 MPa or less. Also, the pressure is preferably 0.1 MPa or more, more preferably 0.5 MPa or more, and even more preferably 1 MPa or more.

[0026] The tensile storage modulus (E 20 ) and tensile storage modulus at 100°C (E 100 ) ratio (E100 / E 20 ) is preferably 0.5 or more and 1 or less, more preferably 0.6 or more and 0.95 or less, and even more preferably 0.7 or more and 0.9 or less. 100 / E 20 Within this range, the change in elastic modulus of the resin composition due to temperature change can be easily reduced by using a resin that can be practically used. In addition, the tensile storage modulus (E 20 ) and tensile storage modulus at 100°C (E 100 ) ratio (E 100 / E 20 ) is, for example, 0.1 or more and 1.1 or less, preferably 0.15 or more and 1 or less, more preferably 0.2 or more and 0.95 or less, and even more preferably 0.3 or more and 0.9 or less. E of resin (b) 100 / E 20 Within this range, the change in elastic modulus of the resin composition due to temperature change can be easily reduced by using a resin that can be practically used.

[0027] The glass transition temperature of the resin (a) is preferably 140°C or more and 200°C or less, more preferably 145°C or more and 195°C or less, even more preferably 150°C or more and 190°C or less, particularly preferably 155°C or more and 185°C or less, and particularly preferably 160°C or more and 180°C or less. If the glass transition temperature of the resin (a) is within this range, the balance between melt moldability and heat resistance is easily excellent. The glass transition temperature can be measured as the peak top temperature of the tensile loss factor (tan δ) of the dynamic elastic modulus measurement, for example, in accordance with JIS K7244-4:1999. The dynamic elastic modulus measurement may be performed in the same manner as the measurement of the tensile storage elastic modulus described above.

[0028] The mass average molecular weight of the resin (b) is, for example, 50,000 or more and 300,000 or less, but preferably 700,000 or more and 260,000 or less. When the mass average molecular weight is 50,000 or more, the elastic modulus at high temperatures can be maintained at a high value, so that the change in the elastic modulus from low to high temperatures is small, and the elastic modulus ratio (E 100 / E 20 ) is easily maintained at a large value. In addition, by making it 300,000 or less, the melt viscosity is not too high, and the melt moldability tends to be excellent. From these viewpoints, the mass average molecular weight of the resin (b) is more preferably 100,000 or more and 200,000 or less, further preferably 110,000 or more and 180,000 or less, and particularly preferably 120,000 or more and 150,000 or less. The mass average molecular weight is a mass average molecular weight calculated by gel permeation chromatography in terms of the molecular weight of standard polystyrene.

[0029] As the resin (a), it is preferable that the elastic modulus is in an appropriate range and the change in the elastic modulus from low to high temperatures is small. For example, specifically, cyclic olefin resins, amorphous polyamides, polysulfones, polyethersulfones, polyphenylsulfones, polyetherimides, polyetherimide sulfones, polyarylates, polymethylmethacrylimides, polyetheretherketones, polyetherketones, polyetherketoneketones, etc. can be used. Among these, cyclic olefin resins are preferable from the viewpoints of excellent heat resistance and melt moldability, small change in elastic modulus even when the environmental temperature during use changes, less influence on sound quality, and low polarity and excellent dispersibility of resin (b). In addition, by using a cyclic olefin resin as resin (a), it is easy to impart water absorption resistance to the resin composition, and the influence of water absorption over time on sound quality can be reduced. Incidentally, a specific description of the cyclic olefin resin is the same as that of the cyclic olefin resin (A) described in the second embodiment below, and therefore the description thereof will be omitted.

[0030] In addition, the resin (b) is preferably a resin whose modulus of elasticity is in an appropriate range and whose change in modulus of elasticity from low to high temperatures is small, and specifically, for example, styrene-based polymers, olefin-based polymers, amide-based polymers, ester-based polymers, vinyl chloride-based polymers, fluorine-based polymers, acrylic-based polymers, etc. can be used. Among these, copolymers are preferred, and styrene-based copolymers are more preferred, from the viewpoint that the modulus of elasticity can be easily adjusted to an appropriate range and can correspond to a wide range of sounds when used with a diaphragm. In addition, by using a styrene-based polymer, particularly a styrene-based copolymer, as the resin (b), it becomes easier to impart water absorption resistance to the resin composition, and the effect of water absorption over time on sound quality can be reduced. Incidentally, a specific description of the styrene-based copolymer is the same as that of the styrene-based copolymer (B) described in the second embodiment below, and therefore the description thereof will be omitted.

[0031] The content ratio of resin (a) and resin (b) in the resin composition is preferably in the range of (a):(b)=99:1 to 1:99 on a mass basis, more preferably in the range of 90:10 to 10:90, even more preferably in the range of 80:20 to 20:80, particularly preferably in the range of 70:30 to 30:70, and particularly preferably in the range of 60:40 to 40:60. If the content ratio of resin (a) and resin (b) is in this range, the elastic modulus of the resin composition tends to be in an appropriate range. In addition, the heat resistance tends to be excellent.

[0032] The resin composition may contain other resin components (c) in addition to the resins (a) and (b) as long as the effects of the present invention are not impaired. The other resin components (c) have a tensile storage modulus at 20°C that is equal to or lower than the tensile storage modulus (E 20 ) is preferably a resin outside the range, for example, each of the resins listed as the other resin component (C) described in the second embodiment described later can be used. In addition, the tensile storage modulus (E 20 As long as the resin is outside the above range, it may be a styrene-based copolymer or a cyclic olefin-based resin. When the resin composition further contains another resin component (c), the content of the other resin component (c) in the resin composition is preferably 0.1% by mass or more, more preferably 0.3% by mass or more, even more preferably 0.5% by mass or more, particularly preferably 1% by mass or more, and particularly preferably 3% by mass or more. Also, the content is preferably 10% by mass or less, more preferably 9% by mass or less, even more preferably 8% by mass or less, particularly preferably 7% by mass or less, and particularly preferably 5% by mass or less. When the resin composition further contains another resin component (c), as long as the content ratio is within the above range, the desired effect can be imparted while maintaining the effect of the present invention.

[0033] The resin composition according to the first aspect may contain various additives such as a heat stabilizer, an antioxidant, an ultraviolet absorber, a light stabilizer, an antibacterial or antifungal agent, an antistatic agent, a lubricant, a pigment, and a dye, within a range that does not impair the effects of the present invention.

[0034] <Second aspect> Next, the resin composition for acoustic components according to the second aspect of the present invention will be described in detail. The resin composition for acoustic components according to the second aspect of the present invention is a resin composition containing a cyclic olefin resin (A) and a styrene copolymer (B). The cyclic olefin resin (A) has a high glass transition temperature and is heat resistant. Furthermore, even if the environmental temperature during use changes, the elastic modulus changes little, and the effect on sound quality is minimal. By including a styrene copolymer (B) in the resin, the elastic modulus can be adjusted to an appropriate range, and when used with a diaphragm, it can accommodate a wide range of sounds. Furthermore, both the cyclic olefin resin (A) and the styrene copolymer (B) have low water absorption, so the effect of water absorption over time on sound quality is minimal. In addition, by using the cyclic olefin resin (A) and the styrene copolymer (B), the folding strength of the film made of the resin composition is likely to be increased, the film has excellent impact resistance, and is less likely to crack or break when used as an acoustic component.

[0035] The content ratio of the cyclic olefin resin (A) and the styrene copolymer (B) in the resin composition according to the second embodiment is preferably in the range of (A):(B)=99:1 to 1:99, more preferably in the range of 90:10 to 10:90, even more preferably in the range of 80:20 to 20:80, particularly preferably in the range of 70:30 to 30:70, and particularly preferably in the range of 60:40 to 40:60. If the content ratio of the cyclic olefin resin (A) and the styrene copolymer (B) is in this range, the resin composition tends to have an appropriate elastic modulus and excellent heat resistance.

[0036] [Cyclic olefin resin (A)] The cyclic olefin resin (A) used in the present invention means a resin having a ring structure derived from a cyclic olefin, with at least a polymerizable cyclic olefin having an ethylenic double bond in the ring as a polymerization component. The cyclic olefin resin (A) is a resin obtained by polymerizing the polymerization components. The cyclic olefin may be a monocyclic olefin or a polycyclic olefin.

[0037] Representative examples of cyclic olefins include norbornenes, cyclopentadienes or dicyclopentadienes, 1,4,5,8-dimethano-1,2,3,4,4a,5,8,8a-octahydronaphthalenes obtained by condensation of norbornenes with cyclopentadiene, hexacyclo[6.6.1.1.1.0.0]heptadecenes-4, and polycyclic olefins such as 6-ethylbicyclo[2.2.1]hept-2-ene synthesized from 1-butene and cyclopentadiene.

[0038] The cyclic olefin may have a substituent. Examples of the substituent include an alkyl group (e.g., a C1-10 alkyl group such as a methyl group, preferably a C1-5 alkyl group), a cycloalkyl group (e.g., a C5-10 cycloalkyl group such as a cyclohexyl group), an aryl group (e.g., a C6-10 aryl group such as a phenyl group), an alkenyl group (e.g., a C2-10 alkenyl group such as a propenyl group), a cycloalkenyl group (e.g., a C5-10 cycloalkenyl group such as a cyclopentenyl group, a cyclohexenyl group), an alkylidene group (e.g., an ethylidene group), Examples of the cyclic olefin include hydrocarbon groups such as C2-10 alkylidene groups such as C2-10 alkylidene groups, preferably C2-5 alkylidene groups; alkoxy groups (e.g., C1-10 alkoxy groups such as methoxy group, preferably C1-6 alkoxy groups); acyl groups (e.g., C2-5 acyl groups such as acetyl group); alkoxycarbonyl groups (e.g., C1-10 alkoxy-carbonyl groups such as methoxycarbonyl group); hydroxyl groups, carboxyl groups, amino groups, substituted amino groups, halogen atoms, haloalkyl groups, nitro groups, cyano groups, oxo groups (=O), heterocyclic groups (nitrogen atom-containing heterocyclic groups such as pyridyl group, etc.). The cyclic olefin may have a substituent, either alone or in combination of two or more.

[0039] Specific examples of the cyclic olefin include monocyclic olefins, bicyclic olefins, tricyclic olefins, polycyclic olefins such as polycyclic olefins having four or more rings, and the like. Examples of the monocyclic olefins include cycloalkenes (for example, cycloC3-10 alkenes such as cyclobutene, cyclopentene, cycloheptene, and cyclooctene), cycloalkadiene (for example, cycloC3-10 alkadiene such as cyclopentadiene), and the like. Bicyclic olefins include bicycloalkenes such as norbornenes (e.g., 2-norbornene, 5-methyl-2-norbornene, 5,5 or 5,6-dimethyl-2-norbornene, 5-ethylidene-2-norbornene, 5-cyano-2-norbornene, 5-methoxycarbonyl-2-norbornene, 5-phenyl-2-norbornene, 5-methyl-5-methoxycarbonyl-2-norbornene, 5,6-dimethoxycarbonyl-2-norbornene, 5,6-di(trifluoromethyl)-2-norbornene, 7-methyl-2-norbornene, 5 ... bicycloalkadienes such as norbornadienes (e.g., 2,5-norbornadiene, 5-methyl-2,5-norbornadiene, 5-cyano-2,5-norbornadiene, 5-methoxycarbonyl-2,5-norbornadiene, 5-phenyl-2,5-norbornadiene, 5,6-dimethyl-2,5-norbornadiene, 5,6-di(trifluoromethyl)-2,5-norbornadiene, 7-oxo-2-norbornadiene, etc.); Examples of tricyclic olefins include tricycloalkenes such as C6-25 tricycloalkenes, such as dihydrodicyclopentadienes (dihydrodicyclopentadiene, etc.); tricycloalkadienes such as dicyclopentadienes (dicyclopentadiene, methyldicyclopentadiene, etc.), C6-25 tricycloalkadienes, such as tricyclo[4.4.0.12,5]undeca-3,7-diene, tricyclo[4.4.0.12,5]undeca-3,8-diene, etc. Examples of polycyclic olefins having four or more rings include tetracyclic olefins such as tetracycloalkenes (e.g., C8-30 tetracycloalkenes such as tetracyclo[4.4.0.12,5.17,10]-3-dodecene, 8-methyltetracyclo[4.4.0.12,5.17,10]-3-dodecene, and 8,9-dimethyltetracyclo[4.4.0.12,5.17,10]-3-dodecene); pentacyclic olefins such as pentacycloalkadienes (e.g., C10-35 pentacycloalkadienes such as tricyclopentadiene); and hexacyclic olefins such as hexacycloalkenes (e.g., C12-40 hexacycloalkenes such as hexacyclo[6.6.1.13,6.02,7.09,1 4]-4-heptadecene).

[0040] These cyclic olefins can be used alone or in combination. Among these cyclic olefins, polycyclic olefins such as norbornenes are preferred. It is more preferred that the cyclic olefin resin has a polycyclic structure.

[0041] The cyclic olefin resin may be a homopolymer or copolymer of a cyclic olefin (for example, a copolymer of a monocyclic olefin and a polycyclic olefin), or a copolymer of a cyclic olefin and a copolymerizable monomer.

[0042] The copolymerizable monomer is not particularly limited as long as it is copolymerizable, but may be any of alkenes (e.g., ethylene, propylene, 1-butene, 1-pentene, 1-hexene, 3-methyl-1-butene, 2-methyl-1-pentene, 3-ethyl-1-pentene, 4-methyl-1-pentene, 4-methyl-1-hexene, 4,4-dimethyl-1-hexene, 4,4-dimethyl-1-pentene, 4-ethyl-1-hexene, 3- Examples of such copolymerizable monomers include C2-20 alkenes such as ethyl-1-hexene, 1-octene, 1-decene, 1-dodecene, 1-tetradecene, 1-hexadecene, 1-octadecene, and 1-eicosene, and chain olefins such as alkadienes (e.g., non-conjugated C5-20 alkadienes such as 1,4-hexadiene, 4-methyl-1,4-hexadiene, 5-methyl-1,4-hexadiene, and 1,7-octadiene). These copolymerizable monomers can be used alone or in combination of two or more. The copolymerizable monomer may be an α-olefin (for example, a C2-10 α-olefin, particularly a C2-6 α-olefin, such as ethylene, propylene, 1-butene, 1-pentene, or 1-hexene).

[0043] Furthermore, as the copolymerizable monomer, polymerizable nitrile compounds (e.g., (meth)acrylonitrile, etc.), (meth)acrylic monomers (e.g., (meth)acrylic acid esters such as methyl (meth)acrylate and ethyl (meth)acrylate, (meth)acrylic acid, etc.), unsaturated dicarboxylic acids or derivatives thereof (e.g., maleic anhydride, etc.), vinyl esters (e.g., vinyl acetate, vinyl propionate, etc.), conjugated dienes (butadiene, isoprene, etc.), etc. may be used alone or in combination of two or more of these copolymerizable monomers.

[0044] The cyclic olefin resin may be a copolymer of a cyclic olefin and a chain olefin, or a resin having a polycyclic olefin (e.g., a bicyclic to hexacyclic olefin) as a polymerization component, particularly a copolymer of a polycyclic olefin (e.g., a monomer having a norbornene skeleton, such as the norbornenes and dicyclopentadienes) and an α-olefin. In particular, a copolymer of a cyclic olefin and a chain olefin (e.g., a copolymer of an α-C2-4 olefin and a polycyclic olefin, such as a copolymer of ethylene and a monomer having a norbornene skeleton) has the properties of both an olefin polymer (e.g., an ethylene polymer) and a cyclic olefin polymer, and by adjusting the copolymerization ratio of the chain olefin, a high molecular weight polymer can be obtained.

[0045] When the cyclic olefin resin (A) is a copolymer of a cyclic olefin (X) and a chain olefin (Y), the copolymerization ratio (X:Y) is preferably in the range of 99:1 to 1:99, more preferably 95:5:10 to 90, further preferably 90:10 to 20:80, particularly preferably 85:15 to 30:70, and particularly preferably 80:20 to 40:60, in terms of molar ratio. If the copolymerization ratio of the cyclic olefin to the chain olefin is in this range, the balance between melt moldability and heat resistance tends to be excellent.

[0046] The cyclic olefin resin may be a resin obtained by addition polymerization, or may be a resin obtained by ring-opening polymerization such as ring-opening metathesis polymerization. In the ring-opening polymerization, a polycyclic olefin may be ring-opened, and for example, an olefin having three or more rings such as tetracyclododecene is preferably ring-opened. In addition, the cyclic olefin resin (for example, a resin obtained by ring-opening metathesis polymerization) may be a hydrogenated resin. In addition, the cyclic olefin resin may be a crystalline or amorphous resin, and may usually be an amorphous resin. The cyclic olefin resin may be prepared by a conventional polymerization method. Examples of the polymerization method include addition polymerization using a Ziegler type catalyst, addition polymerization using a metallocene catalyst, and ring-opening metathesis polymerization using a metathesis polymerization catalyst.

[0047] The glass transition temperature of the cyclic olefin resin (A) is preferably 140° C. or more and 200° C. or less, more preferably 145° C. or more and 195° C. or less, even more preferably 150° C. or more and 190° C. or less, particularly preferably 155° C. or more and 185° C. or less, and particularly preferably 160° C. or more and 180° C. or less. If the glass transition temperature of the cyclic olefin resin (A) is within this range, the balance between melt moldability and heat resistance tends to be excellent.

[0048] The tensile storage modulus (E 20 The elastic modulus (E 20 When the elastic modulus of the entire resin composition is set to be within a desired range described later, the folding strength of a film made of the resin composition can be increased, and impact resistance can be improved by making the elastic modulus 2000 MPa or more. The tensile storage modulus (E 20 ) is more preferably 2150 MPa or more, even more preferably 2300 MPa or more, and is preferably 5000 MPa or less, more preferably 4000 MPa or less, even more preferably 3000 MPa or less. The tensile storage modulus (E 20 ) and tensile storage modulus at 100°C (E 100 ) ratio (E 100 / E 20 ) is preferably 0.5 or more and 1 or less, more preferably 0.6 or more and 0.95 or less, and even more preferably 0.7 or more and 0.9 or less. E of the cyclic olefin resin (A) 100 / E 20 Within this range, the change in elastic modulus of the resin composition due to temperature change can be easily reduced by using a resin that can be practically used.

[0049] The cyclic olefin resin (A) may be polymerized by the above method, or a commercially available product may be used, such as "ZEONOR" and "ZEONEX" manufactured by Zeon Corporation, "ARTON" manufactured by JSR Corporation, "APPEL" manufactured by Mitsui Chemicals, Inc., and "TOPAS" manufactured by Polyplastics Co., Ltd.

[0050] [Styrene-based copolymer (B)] The styrene copolymer (B) used in the present invention is a copolymer of styrene and other components. There is no particular restriction on the copolymerization component, but it is preferable that the component itself functions as a soft segment and forms an elastomer with styrene as a hard segment. Specifically, it is preferable that the soft segment is at least one selected from the group consisting of butadiene, isoprene, ethylene, butylene, propylene, and isobutylene. The styrene-based copolymer (B) is preferably a block copolymer, and specifically, it preferably has a hard block composed of styrene and a soft block composed of one or more of the copolymerization components that compose the soft segment.

[0051] Specific examples of the styrene copolymer (B) include styrene-butadiene copolymer (SB), styrene-butadiene-styrene copolymer (SBS), styrene-isoprene copolymer (SI), styrene-isoprene-styrene copolymer (SIS), styrene-isobutylene copolymer (SIB), styrene-isobutylene-styrene copolymer (SIBS), styrene-butadiene-butylene-styrene copolymer (SBBS), styrene-ethylene-butylene-styrene copolymer (SEBS), styrene-ethylene-propylene-styrene copolymer (SEPS), styrene-ethylene-ethylene-propylene-styrene (SEEPS) copolymer, etc. Among them, from the viewpoints of dispersibility and flexibility in the cyclic olefin resin (A) and small change in elastic modulus from low temperature to high temperature, it is preferable to contain isobutylene as a copolymerization component of the soft segment, specifically, SIB and SIBS, which are copolymers with isobutylene, are preferable, and SIBS is more preferable. Each of the copolymers described above as specific examples may be a block copolymer. For example, SIB is a diblock copolymer, and SIBS is a triblock copolymer.

[0052] The proportion of the styrene component contained in the styrene copolymer (B) is preferably 1% by mass or more and 30% by mass or less, more preferably 3% by mass or more and 28% by mass or less, even more preferably 5% by mass or more and 25% by mass or less, particularly preferably 7% by mass or more and 23% by mass or less, and particularly preferably 10% by mass or more and 20% by mass or less. If the proportion of the styrene component is within this range, the elastic modulus is unlikely to decrease near the glass transition temperature derived from styrene while maintaining the handleability at room temperature, so that the change in elastic modulus from low to high temperatures can be reduced, and the elastic modulus ratio (E 100 / E 20 ) to a large value.

[0053] The mass average molecular weight of the styrene copolymer (B) is, for example, 50,000 or more and 300,000 or less, and preferably 70,000 or more and 260,000 or less. When the mass average molecular weight is 50,000 or more, the change in elastic modulus from low temperature to high temperature becomes small, and the elastic modulus ratio (E 100 / E 20 ) is easily maintained at a large value. In addition, by making it 300,000 or less, the melt viscosity is not too high, and the melt moldability tends to be excellent. From these viewpoints, the mass average molecular weight of the styrene-based copolymer (B) is more preferably 100,000 or more and 200,000 or less, further preferably 110,000 or more and 180,000 or less, and particularly preferably 120,000 or more and 150,000 or less. The mass average molecular weight is a mass average molecular weight calculated in terms of the molecular weight of standard polystyrene by gel permeation chromatography, and can be measured, for example, under the following conditions. Equipment: Tosoh HLC-8320GPC Column: 4 columns connected Shim-pack GPC-806C Shim-pack GPC-804C Shim-pack GPC-8025C Shim-pack GPC-801C Length 300mm, inner diameter 8.0mm Eluent: Chloroform Flow rate: 1ml / min Detector: RI Column thermostat temperature: 40℃ Sample concentration: Approximately 0.3% by mass (20 mg / 4 ml) Injection volume: 20μl

[0054] The tensile storage modulus (E 20 The tensile storage modulus (E 20By setting the tensile storage modulus (E) to 30 MPa or less, it is possible to increase the folding endurance of a film made of the resin composition while maintaining the elastic modulus of the entire resin composition within the above range, and to improve the impact resistance. From these viewpoints, the tensile storage modulus (E 20 ) is more preferably 20 MPa or less, even more preferably 15 MPa or less, particularly preferably 10 MPa or less, and particularly preferably 5 MPa or less. Also, it is preferably 0.1 MPa or more, more preferably 0.5 MPa or more, and even more preferably 1 MPa or more. The tensile storage modulus E of the styrene copolymer (B) at 20°C 20 and tensile storage modulus E at 100°C 100 Ratio of E 100 / E 20 is, for example, 0.1 or more and 1.1 or less, preferably 0.15 or more and 1 or less, more preferably 0.2 or more and 0.95 or less, and further preferably 0.3 or more and 0.9 or less. E of the styrene-based copolymer (B) 100 / E 20 Within this range, the change in elastic modulus of the resin composition due to temperature change can be easily reduced by using a resin that can be practically used.

[0055] The resin composition may contain other resin components (C) in addition to the cyclic olefin resin (A) and the styrene copolymer (B) as long as the effect of the present invention is not impaired. Specific examples of the other resin components (C) include polyethylene, polypropylene, polyvinyl chloride, polystyrene, polyvinylidene chloride, polyvinyl alcohol, ethylene-vinyl alcohol copolymer, polymethylpentene, polyphenylene ether, polyethylene terephthalate, polybutylene terephthalate, polyacetal, aliphatic polyamide, polymethyl methacrylate, polycarbonate, ABS, polyphenylene sulfide, aromatic polyamide, polyarylate, polyetherimide, polyphenylsulfone, polyetherimide sulfone, polyether ketone, polyether ether ketone, polyether ketone ketone, polyether ether ketone ketone, polyether ether ketone ketone, polyamide imide, polysulfone, polyether sulfone, liquid crystal polymer, or copolymers thereof, or mixtures thereof. When the composition further contains another resin component (C), the content of the other resin component (C) in the resin composition is preferably 0.1% by mass or more, more preferably 0.3% by mass or more, even more preferably 0.5% by mass or more, particularly preferably 1% by mass or more, and particularly preferably 3% by mass or more. Also, the content is preferably 10% by mass or less, more preferably 9% by mass or less, even more preferably 8% by mass or less, particularly preferably 7% by mass or less, and particularly preferably 5% by mass or less. When the composition further contains another resin component (C), as long as the content ratio is within the above range, the desired effect can be imparted while maintaining the effect of the present invention.

[0056] The resin composition according to the second embodiment may contain various additives such as a heat stabilizer, an antioxidant, an ultraviolet absorber, a light stabilizer, an antibacterial or antifungal agent, an antistatic agent, a lubricant, a pigment, and a dye, within a range that does not impair the effects of the present invention.

[0057] The tensile storage modulus (E 20) is preferably 1 MPa or more and 1100 MPa or less, more preferably 10 MPa or more and 1050 MPa or less, even more preferably 100 MPa or more and 1000 MPa or less, particularly preferably 200 MPa or more and 900 MPa or less, and particularly preferably 300 MPa or more and 800 MPa or less. If the tensile storage modulus at 20°C is within this range, excellent acoustic characteristics can be easily obtained even when used in acoustic components, particularly diaphragms for electroacoustic transducers, which have become smaller in size in recent years, while maintaining handleability during molding.

[0058] The tensile storage modulus (E 100 ) is preferably 1 MPa or more and 1100 MPa or less, more preferably 10 MPa or more and 1050 MPa or less, even more preferably 100 MPa or more and 1000 MPa or less, particularly preferably 150 MPa or more and 900 MPa or less, and particularly preferably 200 MPa or more and 800 MPa or less. If the tensile storage modulus at 100°C of the resin composition is within this range, it is likely to have excellent heat resistance while maintaining handleability during molding.

[0059] The tensile storage modulus (E 20 ) and tensile storage modulus at 100°C (E 100 ) ratio (E 100 / E 20 ) is preferably 0.5 or more and 1.2 or less, more preferably 0.55 or more and 1.1 or less, even more preferably 0.6 or more and 1 or less, particularly preferably 0.65 or more and 0.97 or less, and particularly preferably 0.7 or more and 0.95 or less. 100 / E 20 Within this range, the moldability is maintained while the change in elastic modulus is small, resulting in excellent heat resistance. This prevents deterioration of sound quality in high-temperature environments, making it easier to reproduce sound from low to high temperatures.

[0060] The water absorption rate of the resin composition according to the second aspect when immersed at 23°C for 24 hours is preferably 0.1% or less. If it is within this range, the effect of water absorption on sound quality can be reduced. Moreover, the water absorption rate according to the second aspect is more preferably 0.07% or less, further preferably 0.05% or less, and particularly preferably 0.03% or less.

[0061] (Method of producing resin composition) The method for producing the resin composition for acoustic components in each embodiment is not particularly limited, but for example, the resin composition for acoustic components can be obtained by melt-kneading the materials constituting the resin composition for acoustic components. As a kneader for melt-kneading, a known kneader such as an extruder such as a single screw or twin screw extruder, or a plastomill can be used. In particular, when two or more resins are mixed and used, the dispersion state of the resin components can be appropriately adjusted by selecting the type of kneader and the kneading conditions, which makes it easy to obtain a resin composition having a desired tensile storage modulus. The melting temperature is adjusted appropriately depending on the type and mixing ratio of the resin, the presence or absence and type of additives, but from the viewpoint of productivity, etc., it is preferably 230° C. or higher, more preferably 240° C. or higher, and even more preferably 250° C. or higher. The melting temperature is preferably 300° C. or lower, more preferably 290° C. or lower, and even more preferably 280° C. or lower. If the melting temperature is within this range, it is easy to sufficiently flow the resin while suppressing decomposition and crosslinking.

[0062] The kneader is preferably an extruder in which the ratio L / D, which is the ratio of the screw length L (mm) to the screw diameter D (mm), is preferably 15 or more, more preferably 20 or more, and preferably 50 or less, more preferably 40 or less. By making the ratio 15 or more, it becomes easier to improve the dispersibility of the resin components and to obtain a resin composition with a desired tensile storage modulus, and by making the ratio 50 or less, it becomes easier to suppress discoloration, outgassing, gel-like foreign matter, and the like, which are caused by thermal degradation due to a long resin residence time or an excessively high resin temperature. The screw configuration of the extruder is preferably a structure having a kneading unit, particularly a spiral kneading unit, in order to improve kneading properties. One or two kneading units are preferred.

[0063] The ratio Q / Ns of the discharge rate Q (kg / hr) during melt kneading to the screw rotation speed Ns (rpm) is preferably 0.01 or more, more preferably 0.05 or more, and preferably 10 or less, more preferably 5 or less. By setting this value within the above range, discoloration of the resin composition and generation of foreign matter caused by an excessively high resin temperature or an excessively long residence time can be suppressed, while improving the dispersibility of each resin component and making it easy to obtain a resin composition having a desired tensile storage modulus.

[0064] A continuous kneader is also preferably used as the kneader. A continuous kneader is a kneader in which a screw rotatably attached in the cylinder of an extruder is provided with a plurality of rotating blades, and a fixed blade is further provided in the cylinder in a state inserted between the plurality of rotating blades. When the screw rotates, the raw material moving along the screw axis passes through the gap formed between the rotating blade and the fixed blade in a zigzag manner, from the center side to the outer periphery side, and then from the outer periphery side to the center side, and is kneaded. Therefore, the three actions of compression, shearing, and replacement can be efficiently given to the raw material, and the dispersibility of each component can be improved more effectively than with a single-screw or twin-screw extruder. There is no particular restriction on the shape of the blade, but for example, a fan-shaped, chrysanthemum-shaped, or mortar-shaped blade can be used. For example, the "NES·KO series" manufactured by Chemical Engineering Co., Ltd. can be mentioned as such a continuous kneader.

[0065] [Film for acoustic components] The film for acoustic components of the present invention (hereinafter sometimes referred to as "the film") is a film made of the resin composition for acoustic components related to the first embodiment or the resin composition for acoustic components related to the second embodiment.

[0066] The thickness of the film is preferably 1 μm or more and 100 μm or less, more preferably 2 μm or more and 50 μm or less, even more preferably 3 μm or more and 35 μm or less, and particularly preferably 4 μm or more and 20 μm or less. If the thickness is within this range, the balance between the handling property and the sound quality is excellent, and further, it tends to contribute to the miniaturization of the diaphragm and the space saving.

[0067] (Film manufacturing method) The film can be produced by a general molding method, such as extrusion molding, injection molding, blow molding, vacuum molding, pressure molding, press molding, etc. In each molding method, the apparatus and processing conditions are not particularly limited, but from the viewpoint of productivity and thickness control, extrusion molding, particularly the T-die method, is preferred. In addition, the resin composition extruded by the T-die may be taken up by, for example, a cast roll.

[0068] The method for producing the film of the present invention is not particularly limited, but for example, the film can be obtained by forming the constituent material of the film (i.e., the resin composition) into a non-stretched or stretched film, and from the viewpoint of secondary processability, it is preferable to obtain it as a non-stretched film. Note that the non-stretched film is a film that is not actively stretched for the purpose of controlling the orientation of the sheet, and also includes a film that is oriented when taken up by a cast roll in the T-die method.

[0069] For example, the resin composition can be produced by melt-kneading each component material to obtain a resin composition, extruding the resin composition, and cooling it. For melt-kneading, a known kneader such as a single-screw or twin-screw extruder or a plastomill can be used. The details of melt-kneading are as described above. The molding can be carried out, for example, by extrusion molding using a die such as a T-die, and it is preferable to cool the mixture using a cast roll.

[0070] The temperature of the casting roll is preferably 50° C. or higher, more preferably 100° C. or higher, and even more preferably 120° C. or higher. When the lower limit of the casting roll temperature is within this range, a film having excellent adhesion to the film, which is less prone to wrinkles due to rapid cooling and has a good appearance is easily obtained. On the other hand, the temperature of the casting roll is preferably 200° C. or less, more preferably 190° C. or less, and even more preferably 180° C. or less. If the upper limit of the casting roll temperature is within this range, the film is less likely to stick to the roll and then leave a trace of adhesion when it is released, and a film with good appearance is easily obtained. In addition, it is also preferable to use a touch roll or an electric adhesion device to improve the adhesion between the casting roll and the film.

[0071] In the case of a non-oriented film, for example, the components constituting the resin composition may be melt-kneaded at the above-mentioned melting temperature to obtain a resin composition, and the resin composition may be press-molded into a film.

[0072] [Use and mode of use] The film for acoustic members of the present invention has excellent heat resistance, an elastic modulus within a specific range, and a small change in elastic modulus from low to high temperatures, and therefore can be suitably used as an acoustic member, in particular a diaphragm for an acoustic member. The film for acoustic components 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 preferably used as a speaker diaphragm, and can be particularly suitably used as a micro-speaker diaphragm for mobile phones and the like.

[0073] The film for acoustic components is suitably secondary processed to be formed into various acoustic components such as diaphragms for acoustic components, preferably diaphragms for electroacoustic transducers, and particularly preferably speaker diaphragms. For example, at least a part of the film for acoustic components may be processed into a dome shape, a cone shape, or the like. The film may also have a tangential edge on the surface. When the film is processed into a dome or cone shape or has a tangential edge, it is preferably used as a diaphragm for acoustic components, more preferably a speaker diaphragm. The secondary processing method is not particularly limited, but it is preferable to heat the film in consideration of the glass transition temperature and softening temperature of the film, and mold the film by press molding, vacuum molding, or the like.

[0074] (Vibration plates for acoustic components) To explain the diaphragm for acoustic components 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 for acoustic components 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, or a combination of these shapes, or any other shape used for diaphragms.

[0075] The film for acoustic members of the present invention may form at least a part of the diaphragm for acoustic members, and for example, the body or edge of the diaphragm may be formed by the film for acoustic members of the present invention, and the edge or body of the diaphragm may be formed by another material. Of course, both the body and the edge may be integrally formed by the film for acoustic members of the present invention, or the entire diaphragm for acoustic members may be formed by the film for acoustic members.

[0076] Fig. 1 is a diagram showing 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 Fig. 1, the diaphragm 1 has a dome portion (body) 1a at the center, a recessed portion 1b to be attached to a voice coil 2, a peripheral portion (edge) 1c, and an external attachment portion 1d on the outer periphery to be attached to a frame or the like. The diaphragm 1 is formed from the film for acoustic components of the present invention.

[0077] FIG. 2 is a diagram showing the structure of a diaphragm 11 according to another embodiment of the present invention, and is a cross-sectional view of the circular diaphragm 11 cut along a plane passing through the center line of the circle in a plan view. As shown in FIG. 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 part of the diaphragm may be processed into a dome shape, and the other part 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.

[0078] 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 a plurality of tangential edges 21e provided on the outer periphery of a circular dome portion (body) 21a, and a tangential edge portion 21h having a plurality of tangential edges 21f arranged on the outer periphery of the tangential edge portion 21g. Note that, although FIG. 3 shows an example in which two tangential edge portions are provided along the radial direction, the number of tangential edge portions may be only one or three or more may be provided along the radial direction.

[0079] 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 a maximum diameter of 25 mm or less, preferably 20 mm or less, and a maximum diameter of 5 mm or more is preferably used. The maximum diameter refers to the diameter when the diaphragm is circular, and the major axis when the diaphragm is elliptical or oval.

[0080] The diaphragm may be formed by the film for acoustic members of the present invention alone, or may be formed by a composite material of the film for acoustic members of the present invention and another member. For example, as described above, either the edge or the body may be formed by another member. Also, the diaphragm may be formed by a laminate of the film for acoustic members and another layer.

[0081] The laminate may, for example, have the above-mentioned film for acoustic members and an adhesive layer provided on at least one surface of the film for acoustic members. By having the adhesive layer, the laminate is more likely to have good damping characteristics. In addition, the laminate is preferably a laminate having the above-mentioned acoustic member film as the front and back layers and the adhesive layer as the intermediate layer. By making such a laminate structure, in addition to the heat resistance, impact resistance and moldability of the acoustic member film of the front and back layers, the excellent damping characteristics of the intermediate layer can be imparted to the laminate. The method of making a diaphragm made of such a laminate is not particularly limited. For example, a method of making a diaphragm by secondary processing a pair of acoustic member films to make molded bodies constituting the front layer and the back layer, respectively, and bonding them via an adhesive used in the intermediate layer, or a method of bonding a pair of acoustic member films via an adhesive used in the intermediate layer to make a laminate film, and secondary processing the laminate film, etc. can be mentioned. In this case, the thickness of the front layer and the back layer is preferably 1 μm or more and 30 μm or less, more preferably 2 μm or more and 25 μm or less, and even more preferably 3 μm or more and 20 μm or less. On the other hand, the thickness of the intermediate layer is preferably 3 μm or more and 50 μm or less, more preferably 5 μm or more and 40 μm or less, and even more preferably 10 μm or more and 30 μm or less. If the material type of the intermediate layer and the thickness of each layer are such a configuration, it is easy to obtain a diaphragm that has excellent damping characteristics while maintaining various mechanical properties and moldability.

[0082] The laminate may include a resin film other than the above-mentioned film for acoustic components in addition to the above-mentioned film for acoustic components and adhesive layer. Examples of resin components used in the resin film include polyether ether ketone resin (PEEK), polyester elastomer (TPEE), polyetherimide resin, polyurethane resin, polybiphenyl ether sulfone resin (PPSU), crystalline polyimide resin, aliphatic polyamide resin, semi-aromatic polyamide resin, and mixtures thereof. When a resin film other than a film for acoustic components is used, the laminate may be a laminate in which one of the front and back layers is a film for acoustic components and the other is a resin film other than a film for acoustic components, with an adhesive layer as an intermediate layer; a laminate laminated in the order of film for acoustic components / resin film other than a film for acoustic components / adhesive layer; or a laminate laminated in the order of film for acoustic components / resin film other than a film for acoustic components / adhesive layer / resin film other than a film for acoustic components / film for acoustic components.

[0083] The adhesive layer used in the laminate may be formed of an adhesive. Examples of the adhesive used in the adhesive layer include acrylic adhesives, rubber adhesives, silicone adhesives, and urethane adhesives. From the viewpoint of adhesion, it is preferable to use an acrylic or silicone adhesive.

[0084] 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, etc., the surface of the film for acoustic components of the present invention or the molded diaphragm may be appropriately treated by coating or laminating an antistatic agent or various elastomers (e.g., urethane-based, silicone-based, hydrocarbon-based, fluorine-based, etc.), vapor-depositing a metal, sputtering, coloring (black, white, etc.), etc. Furthermore, lamination with metals such as aluminum or other films, or compounding with nonwoven fabric, etc. may be appropriately performed. When laminating with another film, the other film is preferably a film made of a resin such as polyether ether ketone, polyester elastomer, thermoplastic polyurethane, polybiphenyl ether sulfone resin (PPSU), crystalline polyimide resin, aliphatic polyamide resin, semi-aromatic polyamide resin, or a mixture thereof, from the viewpoints of tensile storage modulus, heat resistance, and secondary processability. EXAMPLES

[0085] The present invention will be described in detail below with reference to examples, but the present invention is not limited thereto.

[0086] 1. Production of resin composition and film In the examples and comparative examples, the raw materials shown in Table 1 below were used to produce resin compositions and films having the formulations shown in Table 2.

[0087] [Table 1]

[0088] Example 1 A dry blend of (A)-1:(B)-1 = 60:40 (mass ratio) was used as the raw material, which was then put into a Labo Plastomill manufactured by Toyo Seiki Seisakusho Co., Ltd. and melted while being kneaded. At this time, the temperature of the device was 260°C, the rotation speed was 60 rpm, and the kneading time was 10 minutes. The resin composition thus produced was hot-pressed at 260°C to produce an unstretched film having a thickness of 100 μm.

[0089] Example 2 A film was produced in the same manner as in Example 1, except that the mass ratio was (A)-1:(B)-1=40:60.

[0090] Example 3 A film was produced in the same manner as in Example 1, except that the mass ratio was (A)-1:(B)-1=20:80.

[0091] Example 4 A film was produced in the same manner as in Example 1, except that (A)-2 was used instead of (A)-1, and the mass ratio was (A)-2:(B)-1 = 60:40. Example 5 A film was produced in the same manner as in Example 1, except that (A)-2 was used instead of (A)-1, (B)-2 was used instead of (B)-1, and the mass ratio was (A)-2:(B)-2 = 60:40.

[0092] Example 6 A dry blend of (A)-2:(B)-1 = 40:60 (mass ratio) was fed into a twin-screw extruder (L / D = 38) equipped with a Φ25 mm screw, melted while kneading at a temperature of 250°C and a rotation speed of 120 rpm, and extruded using a T-die at an extrusion temperature of 250°C. The extruded resin composition was taken up by a cast roll at 120°C to produce an unstretched film with a thickness of 100 μm.

[0093] Example 7 A film was produced in the same manner as in Example 6, except that (A)-3 was used instead of (A)-2, and the mass ratio was (A)-3:(B)-1 = 60:40.

[0094] Example 8 A film was produced in the same manner as in Example 6, except that (A)-3 was used instead of (A)-2, and the mass ratio was (A)-3:(B)-1 = 50:50.

[0095] Comparative Example 1 A film was produced in the same manner as in Example 1, except that (A)-1 was used alone.

[0096] Comparative Example 2 A film was produced in the same manner as in Example 1, except that (A)-2 was used alone.

[0097] Comparative Example 3 A film was produced in the same manner as in Example 1, except that (A)-3 was used alone.

[0098] Comparative Example 4 Polyetherimide ((C)-1) was fed into a single-screw extruder equipped with a φ40 mm screw, melted while being kneaded 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 produce an unstretched film with a thickness of 100 μm.

[0099] Comparative Example 5 Polyether ether ketone ((C)-2) was fed into a single-screw extruder equipped with a φ40 mm screw, melted while being kneaded 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 produce an unstretched film with a thickness of 100 μm.

[0100] Comparative Example 6 Polyamide 9T ((C)-3) was fed into a single-screw extruder equipped with a φ40 mm screw, melted while kneading at a temperature of 320° C., and extruded using a T-die at an extrusion temperature of 320° C. The extruded resin was taken up by a casting roll at 120° C. to produce an unstretched film with a thickness of 100 μm.

[0101] 2. Evaluation and measurement methods The resin compositions and films in the above Examples and Comparative Examples were evaluated and measured for various items as follows.

[0102] (1) Tensile storage modulus A test piece of 5 mm×8 cm (thickness 100 μm) was cut out from the film 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 ) was measured. In addition, since the extruded films of Examples 6 to 8 and Comparative Example 5 have directionality, measurements were made in the machine direction (the direction in which the resin composition is extruded from the T-die (MD)) and the transverse direction (TD) of the film, and the average value was taken as the tensile storage modulus. In Comparative Examples 4 and 6, the MD was not measured, so the TD value is shown as a reference value.

[0103] (2) Tensile storage modulus at 20°C (E 20 ) and tensile storage modulus at 100°C (E 100 ) ratio (E 100 / E 20 ) From the values ​​obtained by the measurement in (1), E 100 / E 20 was calculated.

[0104] (3) Water absorption rate A test piece of 10 cm×10 cm (thickness 100 μm) was cut out from the film obtained in each of the Examples and Comparative Examples to obtain a measurement sample. In accordance with JIS K7029:2000, the obtained measurement sample was immersed in water at 23° C. for 24 hours, and the water absorption rate was measured from the change in mass before and after immersion.

[0105] The evaluation and measurement results for Examples 1 to 8 and Comparative Examples 1 to 6 are summarized in Table 2 below.

[0106] [Table 2]

[0107] The resin compositions used in Examples 1 to 8 have a suitable tensile storage modulus at 20°C, and are presumed to have excellent sound quality and reproducibility when used, for example, as a diaphragm. In addition, the tensile storage modulus and ratio (E 100 / E 20 ) is in an appropriate range, there is little change in elastic modulus, and the heat resistance is excellent. In addition, the water absorption rate is low, so it is also excellent in low water absorption. It is also estimated that the effect of temperature and humidity on sound quality and playability is small.

[0108] On the other hand, the resin compositions used in Comparative Examples 1 to 6 have a high elastic modulus, and it is presumed that when used as a diaphragm, for example, the sound quality, especially the sound quality and reproducibility at low temperatures, is poor. Also, since highly polar super engineering plastics are used in Comparative Examples 4 to 6, it is presumed that the water absorption rate is high and that humidity has a large effect on the sound quality and reproducibility. Furthermore, from the investigations conducted by the present inventors thus far, it is presumed that the resin compositions of Examples 1 to 8 are also excellent in impact resistance, such as folding strength.

Claims

1. The present invention comprises a cyclic olefin resin (A) and a styrene copolymer (B), the glass transition temperature of the cyclic olefin resin (A) being 140° C. or higher and 200° C. or lower, The resin composition for acoustic components, wherein the styrene-based copolymer (B) is a styrene-isobutylene-styrene triblock copolymer or a styrene-isobutylene diblock copolymer.

2. Tensile storage modulus at 20 ° C (E ２０ 2. The resin composition for acoustic components according to claim 1, wherein the compressive strength (S) is 1 MPa or more and 1100 MPa or less.

3. Tensile storage modulus at 100 ° C (E １００ 3. The resin composition for acoustic components according to claim 1 or 2, wherein the compressive strength (S) is 1 MPa or more and 1100 MPa or less.

4. Tensile storage modulus at 20 ° C (E ２０ ) to the tensile storage modulus at 100 ° C. (E １００ / E ２０ 4. The resin composition for acoustic components according to claim 1, wherein the value of (a) is 0.5 or more and 1.2 or less.

5. The resin composition for acoustic components according to any one of claims 1 to 4, wherein the content ratio of the cyclic olefin resin (A) and the styrene copolymer (B) in the resin composition is, on a mass basis, in the range of (A):(B) = 99:1 to 1:

99.

6. The resin composition for acoustic components according to any one of claims 1 to 5, wherein the mass average molecular weight of the styrene-based copolymer (B) is 50,000 or more and 300,000 or less.

7. The resin composition for acoustic components according to any one of claims 1 to 6, wherein the cyclic olefin resin (A) contains at least a polycyclic olefin as a polymerization component.

8. The styrene-based copolymer (B) is a copolymer of at least one soft segment selected from the group consisting of butadiene, isoprene, ethylene, butylene, propylene, and isobutylene and styrene. The resin composition for acoustic members according to any one of claims 1 to 7.

9. The resin composition for acoustic components according to any one of claims 1 to 8, wherein the proportion of a styrene component contained in the styrene-based copolymer (B) is 1% by mass or more and 30% by mass or less.

10. The resin composition for acoustic components according to any one of claims 1 to 9, which has a water absorption rate of 0.1% or less when immersed at 23°C for 24 hours.

11. A film for acoustic components comprising the resin composition according to any one of claims 1 to 10.

12. The film for acoustic members according to claim 11, wherein at least a portion of the film is processed into at least one of a dome shape and a cone shape.

13. The film for acoustic members according to claim 11 or 12, which has a tangential edge on its surface.

14. The film for acoustic members according to any one of claims 11 to 13, which is used for a diaphragm for an electroacoustic transducer.

15. A laminate comprising the film for acoustic members according to any one of claims 11 to 14 and an adhesive layer provided on at least one surface of the film for acoustic members.

16. A diaphragm for acoustic components, which is obtained by molding the film for acoustic components according to any one of claims 11 to 14 or the laminate according to claim 15.

17. The diaphragm for acoustic members according to claim 16, which is a speaker diaphragm.

18. A method for using the film for acoustic members according to any one of claims 11 to 14, or the laminate according to claim 15, as an acoustic member.

19. Use of the film for acoustic members according to any one of claims 11 to 14, or the laminate according to claim 15 as an acoustic member.

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