JP2021141393A - Resin composition for acoustic member, film for acoustic member, laminate and diaphragm for acoustic member - Google Patents

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

The present invention relates to a resin composition for an acoustic member, a film for an acoustic member, a laminate provided with a film for an acoustic member, and a diaphragm for an acoustic member formed from the film for an acoustic member and the laminate, and above all, vibration for an electroacoustic converter. The present invention relates to a resin composition for an acoustic member, a film for an acoustic member, a laminate, and a diaphragm for an acoustic member, which can be suitably used as a plate, particularly a speaker diaphragm.

For example, with the widespread use of small electronic devices such as smartphones, PDAs, notebook computers, DVDs, LCD TVs, digital cameras, and portable music devices, small speakers (usually called microspeakers) and small ones used in these electronic devices Demand for small electro-acoustic converters such as microphones and earphones is increasing.

Generally, the diaphragm used in the electro-acoustic converter, especially the speaker diaphragm, has a low density in order to maintain the acoustic radiated sound pressure level, and has a high rigidity in order to suppress distortion and maintain a large allowable input. In addition, it is required that the elastic coefficient is in a specific range in order to widen the reproduction frequency band, and that the internal loss is large in order to suppress the split vibration of the diaphragm and flatten the frequency characteristics. In addition, when used in the vicinity of a voice coil, which is the drive source of a speaker, or in an in-vehicle speaker, the diaphragm is exposed to high temperatures for a long time, so heat resistance that can withstand such usage conditions is required. It becomes.

Cyclic olefin resins, polyetheretherketone resins, polyamide resins, polyetherimide resins and the like having excellent acoustic characteristics have been studied for such diaphragms for electroacoustic converters from the past. For example, Patent Document 1 and Patent Document 2 disclose a diaphragm containing a cyclic olefin resin as a main component, and describe that the diaphragm has excellent acoustic characteristics. Further, Patent Document 3 discloses a method for producing a diaphragm film made of polyetheretherketone resin, which can improve the uniformity of sound quality of the diaphragm. Patent Document 4 discloses a method for producing a film for a speaker diaphragm made of a polyamide resin, which can obtain excellent moisture resistance, water resistance, heat resistance, light weight, moldability, and sound quality characteristics.

On the other hand, in recent years, with the miniaturization of electroacoustic transducers, especially speakers, due to the higher functionality and performance of small electronic devices, the materials with better reproducibility in a wider range, especially bass, that is, the elastic modulus has been compared. There is a demand for low-quality materials. Further, since the operating environment temperature becomes high as the output increases, there is a demand for a material in which the change in sound quality from low temperature to high temperature is small, that is, the change in elastic modulus from low temperature to high temperature is small.

Japanese Unexamined Patent Publication No. 6-225383 Japanese Unexamined Patent Publication No. 2011-176621 Japanese Unexamined Patent Publication No. 2018-062153 Japanese Unexamined Patent Publication No. 2016-167757

However, the diaphragm described in Patent Document 1 uses a cyclic olefin resin alone or by adding a 4-methylpentene resin or various fillers, and there is a concern that the elastic modulus is high. Actually, the elastic modulus values described in the examples all exceed 2000 MPa, which is not suitable for sound reproducibility, especially low-pitched sound reproducibility, and does not meet the characteristics required for recent diaphragms. ..

Further, the diaphragm described in Patent Document 2 uses a cyclic olefin resin and polypropylene as an olefin resin in a blend, and there is a concern that the elastic modulus is also high. Furthermore, it has been clarified by the study of the present inventor that there is a problem in durability because the interface between the cyclic olefin resin and polypropylene is weak.

Further, the diaphragms described in Patent Documents 3 and 4 have a high elastic coefficient and have a problem in sound reproducibility, particularly low-pitched sound reproducibility. In addition, since they have a high water absorption rate, the environmental humidity when the diaphragm is used. It has also been clarified by the study of the present inventor that there is a problem that the change in the amount of water and water absorption due to use over time affect the sound quality.

The present invention has been made under such circumstances, and provides a resin composition for an acoustic member having an elastic modulus in an appropriate range, a small change in elastic modulus due to a temperature change, and further high heat resistance. The purpose is to do that.

As a result of diligent studies, the present inventors have succeeded in finding a resin composition capable of solving the above-mentioned problems of the prior art, and have completed the present invention.

That is, the present invention provides the following [1] to [29].
[1] The tensile storage elastic modulus (E ₂₀ ) at 20 ° C. is 1100 MPa or less, and the ratio (E ₁₀₀ / _{) of the tensile storage elastic modulus (E 20} ) at 20 ° C. and the tensile storage elastic modulus (E _{100) at 100 ° C.} A _{resin composition for an acoustic member, wherein E 20} ) is 0.5 or more and 1.2 or less.
[2] The tensile storage modulus at ₂₀ ℃ _(E 20) and the ratio of the tensile storage modulus at _{100 ℃ (E 100) (E} 100 / E 20) is 0.5 or more and 1 or less, the above-mentioned [1] The resin composition for an acoustic member according to.
[3] Tensile storage modulus at 20 ° C. and _{(E 20)} is not less than 2000MPa resin (a), a tensile at 20 ° C. storage elastic modulus _{(E 20)} includes a resin (b) is less than 50 MPa, the The resin composition for an acoustic member according to [1] or [2].
[4] The ratio _(E 100 _/ E ₂₀₎ of the resin tensile storage modulus at 20 ° C. of _{(b) (E 20)} and the tensile storage modulus at ₁₀₀ ℃ _(E 100) 0.1 to 1.1 The resin composition for an acoustic member according to the above [3].
[5] The ratio of the tensile storage modulus at 20 ° C. of the resin _{(a) (E 20)} and the tensile storage modulus at _{100 ℃ (E 100) (E} 100 / E 20) is 0.5 or more and 1 or less , The resin composition for an acoustic member according to the above [3] or [4].
[6] The resin composition for an acoustic member according to any one of [3] to [5] above, wherein the glass transition temperature of the resin (a) is 140 ° C. or higher and 200 ° C. or lower.
[7] The resin composition for an acoustic member according to any one of [3] to [6] above, 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 an acoustic member 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 an acoustic member according to any one of the above [3] to [8], wherein the resin (b) is a styrene-based copolymer (B).

[10] A resin composition for an acoustic member containing a cyclic olefin resin (A) and a styrene copolymer (B).
[11] The resin composition for an acoustic member according to the above [10], wherein the tensile storage elastic modulus (E _{20) at 20 ° C. is 1 MPa or more and 1100 MPa or less.}
[12] The resin composition for an acoustic member according to the above [10] or [11], wherein the tensile storage elastic modulus (E _{100) at 100 ° C. is 1 MPa or more and 1100 MPa or less.}
[13] The ratio of the tensile storage modulus at ₂₀ ℃ _(E 20) and the tensile storage modulus at _{100 ℃ (E 100) (E} 100 / E 20) is 0.5 to 1.2, the [ 10] The resin composition for an acoustic member according to any one of [12].
[14] The resin composition for an acoustic member 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 an acoustic member 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.

[16] The resin composition for an acoustic member 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 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 isoprene. 9] The resin composition for an acoustic member according to any one of [16].
[18] The resin composition for an acoustic member according to any one of [9] to [17] above, wherein the proportion of the styrene component contained in the styrene-based copolymer (B) is 1% by mass or more and 30% by mass or less. thing.
[19] The above-mentioned [9] to [18], wherein the styrene-based copolymer (B) is a styrene-isobutylene-styrene triblock copolymer or a styrene-isobutyrene block copolymer. Resin composition for acoustic members.
[20] The resin composition for an acoustic member according to any one of the above [1] to [19], wherein the water absorption rate when immersed at 23 ° C. for 24 hours is 0.1% or less.

[21] A film for an acoustic member made of the resin composition according to any one of the above [1] to [20].
[22] The film for an acoustic member according to the above [21], wherein at least a part thereof is processed into at least one of a dome shape and a cone shape.
[23] The film for an acoustic member according to any one of the above [21] and [22], which is formed by imparting a tangential edge to the surface.
[24] The film for an acoustic member according to any one of the above [21] to [23], which is used for a diaphragm for an electroacoustic converter.
[25] A laminate having an acoustic member film according to any one of the above [21] to [24] and an adhesive layer provided on at least one surface of the acoustic member film.
[26] A diaphragm for an acoustic member formed by molding the film for an acoustic member according to any one of the above [21] to [24] or the laminate according to the above [25].
[27] The diaphragm for an acoustic member according to the above [26], which is a speaker diaphragm.
[28] A method of using the film for an acoustic member according to any one of the above [21] to [24] or the laminate according to the above [25] as an acoustic member.
[29] Use as the acoustic member film according to any one of the above [21] to [24], or as an acoustic member of the laminate according to the above [25].

According to the present invention, it is possible to provide a resin composition for an acoustic member having an elastic modulus in an appropriate range, a small change in elastic modulus due to a temperature change, and excellent heat resistance. Further, the diaphragm for an electro-acoustic converter such as a speaker diaphragm using the film for an acoustic member made of the resin composition of the present invention has excellent sound reproduction from a low temperature range to a high temperature range, and can be used in a high temperature or the like. It can be expected that problems such as affecting the sound quality are unlikely to occur.

It is sectional drawing which shows the structure of the microspeaker diaphragm 1 which concerns on one Embodiment of this invention. It is sectional drawing which shows the structure of the microspeaker diaphragm 11 which concerns on another Embodiment of this invention. It is a top view which shows the structure of the microspeaker diaphragm 21 which concerns on another Embodiment of this invention.

[Resin composition for acoustic members]
<First aspect>
First, the resin composition for an acoustic member according to the first aspect of the present invention (hereinafter, the resin composition for an acoustic member may be abbreviated as "resin composition") will be described in detail. The resin composition according to the first aspect is a tensile at 20 ° C. storage elastic modulus _{(E 20)} is 1100MPa or less, the tensile storage modulus at ₂₀ ℃ _(E 20) and the tensile storage modulus at 100 ° C. _{(E 100} ) ratio of _(E 100 _/ E ₂₀₎ is 0.5 or more and 1.2 or less.
In the present invention, with the above configuration, 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. Further, since the change in elastic modulus due to the temperature change is small, it can be expected that the change in sound quality from the low temperature range to the high temperature range is small, the sound reproduction is excellent, and the deterioration of sound quality in a high temperature environment is less likely to occur.

As described above, the resin composition according to the first aspect of the present invention has a tensile storage elastic modulus (E ₂₀ ) at 20 ° C. of 1100 MPa or less. If the tensile storage elastic modulus (E ₂₀ ) at 20 ° C. is larger than 1100 MPa, there is a risk that problems will occur in sound reproducibility, especially in bass reproducibility, when used in acoustic members, especially diaphragms for electroacoustic converters that have become smaller in recent years. There is.
The tensile storage elastic modulus (E ₂₀ ) at 20 ° C. is preferably 1 MPa or more and 1100 MPa or less, more preferably 10 MPa or more and 1050 MPa or less, further preferably 100 MPa or more and 1000 MPa or less, and 200 MPa or more. , 900 MPa or less is particularly preferable, and 300 MPa or more and 800 MPa or less are particularly preferable. When the tensile storage elastic modulus at 20 ° C. is within the above range, excellent acoustic characteristics can be obtained even when used for an acoustic member, particularly a diaphragm for an electroacoustic converter to be miniaturized, while maintaining handleability at the time of molding. It will be easier.

The tensile storage elastic modulus refers to a value obtained from a dynamic elastic modulus measurement according to JIS K7244-4: 1999, and details are as described in Examples. The same applies to the tensile storage elastic modulus described below. As the test piece for obtaining the tensile storage elastic modulus, a film may be prepared from the resin composition or the resin alone by, for example, press molding or extrusion molding, and the film may be used as the test piece. In the case of extrusion molding, it is better to manufacture without stretching, but since there is directionality, it is possible to measure MD (extrusion direction) and TD (direction orthogonal to MD in the film plane) and obtain the average value. good. When there is no directionality such as press molding, measurement is performed in only one direction, and the measured value is used as the tensile storage elastic modulus.

Further, the resin composition according to the first aspect of the present invention preferably has a tensile storage elastic modulus (E ₁₀₀ ) at 100 ° C. of 1 MPa or more and 1100 MPa or less, and more preferably 10 MPa or more and 1050 MPa or less. It is 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. When the tensile storage elastic modulus at 100 ° C. of the resin composition is within such a range, the heat resistance is likely to be excellent while maintaining the handleability at the time of molding. Further, since the change in elastic modulus in the high temperature range is small, it is expected that excellent acoustic characteristics can be obtained even in a high temperature environment.

In the resin composition according to the first aspect of the present invention, the ratio E ₁₀₀ / E _{20 of the tensile storage elastic modulus E 20 at 20} ° C. and the tensile storage elastic modulus E ₁₀₀ at 100 ° C. is 0.5 or more and 1.2 or less. be. When the ratio E ₁₀₀ / E ₂₀ is smaller than 0.5 or larger than 1.2, the change in elastic modulus with temperature change becomes large and the heat resistance decreases. Further, since the elastic modulus changes greatly in the high temperature region, the sound quality in the high temperature environment tends to deteriorate, and it becomes difficult to improve the sound reproduction from the low temperature region to the high temperature region.
_{The ratio E 100} / E ₂₀ of the resin composition for an acoustic member according to the first aspect of the present invention is preferably 0.55 or more and 1.1 or less, and preferably 0.6 or more and 1 or less. It is more preferably 0.65 or more and 0.97 or less, and particularly preferably 0.7 or more and 0.95 or less. Within the range where E ₁₀₀ / E ₂₀ is applied, the moldability is maintained and the change in elastic modulus is small, so that the heat resistance is excellent. Therefore, it is easy to prevent deterioration of sound quality in a high temperature environment and improve sound reproducibility from a low temperature range to a high temperature range.

The water absorption rate of the resin composition according to the first aspect when immersed at 23 ° C. for 24 hours is preferably 0.1% or less. Within such a range, the influence of water absorption on sound quality can be reduced. The water absorption rate according to the first aspect 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 in accordance with, for example, JIS K7209: 2000 by preparing a film from the resin composition as shown in Examples and using the film as a test piece.

[Resin (a), (b)]
The resin composition according to the first aspect, the tensile storage modulus at 20 ° C. and _{(E 20)} is not less than 2000MPa resin (a), a tensile at 20 ° C. storage elastic modulus _{(E 20)} is less than 50MPa resin It is preferable to include (b). By using the resins (a) and (b) having different tensile storage elastic moduli in this way, while maintaining the elastic modulus of the entire resin composition within the above range, a molded product such as a film made of the resin composition can be used. It becomes easy to improve the impact resistance by increasing the folding resistance and the like, and cracks and breakages are less likely to occur when used as an acoustic member.

From the above viewpoint, the tensile storage elastic modulus (E ₂₀ ) of the resin (a) is more preferably 2150 MPa or more, further preferably 2300 MPa or more, and preferably 5000 MPa or less, more preferably 4000 MPa or less, still more preferably 3000 MPa or more. It is as follows.
From the above viewpoint, the tensile storage elasticity (E ₂₀ ) of the resin (b) is more preferably 30 MPa or less, further preferably 15 MPa or less, particularly preferably 10 MPa or less, and particularly preferably 5 MPa or less. Further, it is preferably 0.1 MPa or more, more preferably 0.5 MPa or more, still more preferably 1 MPa or more.

Tensile storage modulus at 20 ° C. of the resin _{(a) (E 20)} and the ratio of the tensile storage modulus at _{100 ℃ (E 100) (E} 100 / E 20) is 0.5 or more, preferably 1 or less , 0.6 or more and 0.95 or less, and more preferably 0.7 or more and 0.9 or less. _{As long as E 100} / E ₂₀ of the resin (a) is applied, it is easy to reduce the change in elastic modulus due to the temperature change of the resin composition by using a practically usable resin.
The ratio of resin tensile storage modulus at 20 ° C. of _{(b) (E 20)} and the tensile storage modulus at _{100 ℃ (E 100) (E} 100 / E 20) , for example 0.1 or higher, 1.1 or less However, it is 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. _{As long as E 100} / E ₂₀ of the resin (b) is applied, it is easy to reduce the change in elastic modulus due to the temperature change of the resin composition by using a practically usable resin.

The glass transition temperature of the resin (a) is preferably 140 ° C. or higher and 200 ° C. or lower, more preferably 145 ° C. or higher and 195 ° C. or lower, and further preferably 150 ° C. or higher and 190 ° C. or lower. It is particularly preferably 155 ° C. or higher and 185 ° C. or lower, and particularly preferably 160 ° C. or higher and 180 ° C. or lower. Within the range where the glass transition temperature of the resin (a) is applied, the balance between melt moldability and heat resistance tends to be excellent. The glass transition temperature can be measured as the peak top temperature of the tensile loss coefficient (tan δ) of the dynamic elastic modulus measurement, for example, in accordance with JIS K7244-4: 1999. The dynamic elastic modulus may be measured in the same manner as the above-mentioned measurement of the tensile storage elastic modulus.

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 260000 or less. When the mass average molecular weight is 50,000 or more, the elastic modulus at high temperature can be maintained at a high value, so that the change in elastic modulus from low temperature to high temperature becomes small, and the elastic modulus ratio of the resin (b) and the resin composition (E ₁₀₀ /). It _{becomes easier to maintain E 20} ) at a large value. Further, when it is set to 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 the mass average molecular weight converted to the standard polystyrene molecular weight of the gel permeation chromatography method.

The resin (a) is preferably a resin having an elastic coefficient in an appropriate range and a small change in the elastic coefficient from a low temperature to a high temperature. For example, specifically, a cyclic olefin resin or an amorphous resin. Polysulfone, polysulfone, polyethersulfone, polyphenylsulfone, polyetherimide, polyetherimidesulfone, polyarylate, polymethylmethacrylimide, polyether ether ketone, polyether ketone, polyether ketone ketone and the like can be used. Among these, the resin (b) has excellent heat resistance and melt moldability, has a small change in elastic modulus even when the environmental temperature during use changes, has less influence on sound quality, and has a low polarity. A cyclic olefin resin is preferable from the viewpoint of excellent dispersibility. Further, by using the cyclic olefin resin as the resin (a), it becomes easy to impart water absorption resistance to the resin composition, and the influence of water absorption over time on the sound quality can be reduced.
Since the specific description of the cyclic olefin resin is the same as that of the cyclic olefin resin (A) described in the second aspect described later, the description thereof will be omitted.

Further, the resin (b) is preferably a resin having an elastic coefficient in an appropriate range and a small change in elastic coefficient from a low temperature to a high temperature. For example, specifically, a styrene polymer or an olefin. System-based polymers, amide-based polymers, ester-based polymers, vinyl chloride-based polymers, fluorine-based polymers, acrylic-based polymers and the like can be used. Among these, copolymers are preferable, and styrene-based copolymers are preferable, from the viewpoint that the elastic modulus can be easily adjusted in an appropriate range and can be used in a wide range when used with a diaphragm. More preferable. Further, by using a styrene-based polymer, particularly a styrene-based copolymer, as the resin (b), it becomes easy to impart water absorption resistance to the resin composition, and the influence of water absorption over time on sound quality can be reduced.
Since the specific description of the styrene-based copolymer is the same as that of the styrene-based copolymer (B) described in the second aspect described later, the description thereof will be omitted.

The content ratio of the resin (a) and the resin (b) in the resin composition is preferably in the range of (a): (b) = 99: 1 to 1:99 on a mass basis, and is 90:10 to 10 The range of: 90 is more preferable, the range of 80:20 to 20:80 is further preferable, the range of 70:30 to 30:70 is particularly preferable, and the range of 60:40 to 40:60 is particularly preferable. It is particularly preferable that the range is. As long as the content ratio of the resin (a) and the resin (b) is within such a range, the elastic modulus of the resin composition tends to be in an appropriate range. In addition, the heat resistance tends to be excellent.

The resin composition may contain other resin components (c) in addition to the resin (a) and the resin (b) as long as the effects of the present invention are not impaired. The other resin component (c) is preferably a resin whose tensile storage elastic modulus at 20 ° C. is outside the range of _{the tensile storage elastic modulus (E 20) shown in the resins (a) and (b).} Each resin listed as another resin component (C) described in the second aspect described later can be used. _{Further, any resin outside the range of the tensile storage elastic modulus (E 20} ) shown in the resins (a) and (b) may be a styrene copolymer or a cyclic olefin resin.
When the other resin component (c) is further contained, the content of the other resin component (c) is preferably 0.1% by mass or more, preferably 0.3% by mass or more in the resin composition. Is more preferable, 0.5% by mass or more is further preferable, 1% by mass or more is particularly preferable, and 3% by mass or more is particularly preferable. Further, it is preferably 10% by mass or less, more preferably 9% by mass or less, further preferably 8% by mass or less, particularly preferably 7% by mass or less, and 5% by mass or less. It is especially preferable to have. When the other resin component (c) is further contained, a necessary effect can be appropriately imparted while maintaining the effect of the present invention as long as the content ratio is within such a range.

The resin composition according to the first aspect is a heat stabilizer, an antioxidant, an ultraviolet absorber, a light stabilizer, an antibacterial / antifungal agent, an antistatic agent, a lubricant, a pigment, as long as the effect of the present invention is not impaired. , Dyes and other additives may be included.

<Second aspect>
Next, the resin composition for an acoustic member according to the second aspect of the present invention will be described in detail. The resin composition for an acoustic member 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 excellent in heat resistance. Furthermore, even if the ambient temperature during use changes, the elastic modulus does not change much, and the effect on sound quality is small. By including the styrene-based copolymer (B) here, the elastic modulus can be adjusted in an appropriate range, and when used with a diaphragm, it can correspond to a wide range. Further, since both the cyclic olefin resin (A) and the styrene copolymer (B) have low water absorption, the water absorption over time has little effect on the sound quality.
Further, by using the cyclic olefin resin (A) and the styrene copolymer (B), the folding strength of the film made of the resin composition tends to be high, the impact resistance is excellent, and the film is used as an acoustic member. When it is used, cracks and breakage are less likely to occur.

The content ratio of the cyclic olefin resin (A) and the styrene copolymer (B) in the resin composition according to the second aspect is based on mass, (A): (B) = 99: 1 to 1:99. It is preferably in the range of 90:10 to 10:90, more preferably in the range of 80:20 to 20:80, and more preferably in the range of 70:30 to 30:70. It is particularly preferable to be in the range of 60:40 to 40:60. As long as the content ratio of the cyclic olefin resin (A) and the styrene copolymer (B) is within such a range, the resin composition tends to have an elastic modulus in an appropriate range and excellent heat resistance.

[Cyclic olefin resin (A)]
The cyclic olefin resin (A) used in the present invention means a resin having a cyclic olefin-derived ring structure, which comprises 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 a polymerization component. The cyclic olefin may be a monocyclic olefin or a polycyclic olefin.

Typical cyclic olefins include, for example, norbornenes, cyclopentadiene or dicyclopentadiene, and 1,4,5,8-dimethano-1,2,3,4 obtained by condensation of norbornenes and cyclopentadiene. , 4a, 5,8,8a-octahydronaphthalene, hexacyclo [6.6.1.1.1.1.0.0] heptadecene-4, 1-butene and 6-ethylbicyclo synthesized from cyclopentadiene [2.2.1] Polycyclic olefins such as hept-2-ene can be exemplified.

Further, the cyclic olefin may have a substituent. Examples of the substituent include an alkyl group (for example, a C1-10 alkyl group such as a methyl group, preferably a C1-5 alkyl group), a cycloalkyl group (for example, a C5-10 cycloalkyl group such as a cyclohexyl group), and an aryl group. (For example, C6-10aryl group such as phenyl group), alkenyl group (for example, C2-10alkenyl group such as propenyl group), cycloalkenyl group (for example, cyclopentenyl group, cyclohexenyl group and the like C5-10cyclo A hydrocarbon group such as an alkenyl group (such as an alkenyl group), an alkylidene group (eg, a C2-10 alkylidene group such as an ethylidene group, preferably a C2-5 alkylidene group); an alkoxy group (eg, a C1-10 alkoxy group such as a methoxy group), Preferably C1-6 alkoxy group); acyl group (eg, C2-5 acyl group such as acetyl group); alkoxycarbonyl group (eg, C1-10 alkoxy-carbonyl group such as methoxycarbonyl group); hydroxyl group, carboxyl Examples thereof include a group, an amino group, a substituted amino group, a halogen atom, a haloalkyl group, a nitro group, a cyano group, an oxo group (= O), and a heterocyclic group (such as a nitrogen atom-containing heterocyclic group such as a pyridyl group). The cyclic olefin may have a substituent alone or in combination of two or more.

Specific examples of cyclic olefins include monocyclic olefins, bicyclic olefins, tricyclic olefins, and polycyclic olefins such as polycyclic olefins having four or more rings.
Examples of monocyclic olefins include cycloalkenes (eg, cycloC3-10 alkenes such as cyclobutene, cyclopentene, cycloheptene, and cyclooctene), cycloalkanes (eg, cycloC3-10 alkanes such as cyclopentadiene), and the like. Can be mentioned.
Bicyclic olefins include bicycloalkenes, such as norbornadiene (eg, 2-norbornadiene, 5-methyl-2-norbornadiene, 5,5 or 5,6-dimethyl-2-norbornadiene, 5-ethylidene-2-. Norbornadiene, 5-cyano-2-norbornadiene, 5-methoxycarbonyl-2-norbornadiene, 5-phenyl-2-norbornene, 5-methyl-5-methoxycarbonyl-2-norbornadiene, 5,6-dimethoxycarbonyl-2-norbornadiene , 5,6-di (trifluoromethyl) -2-norbornene, 7-oxo-2-norbornene, etc.) C4-20 bicycloalkene; bicycloalkadiene, eg, norbornadiene (eg, 2,5-norbornadiene, etc.) 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.) and the like.
Tricyclic olefins include, for example, tricycloalkenes, such as C6-25 tricycloalkenes such as dihydrodicyclopentadienes (such as dihydrodicyclopentadiene); tricycloalkanes, such as dicyclopentadiene (such as dicyclopentadiene). Dicyclopentadiene, methyldicyclopentadiene, etc.), tricyclo [4.4.0.12,5] undeca-3,7-diene, tricyclo [4.4.0.12,5] undeca-3,8-diene C6-25 tricycloalkanediene and the like can be mentioned.
Examples of tetracyclic olefins having four or more rings include tetracycloalkenes (eg, tetracyclo [4.4.0.12,5.17,10] -3-dodecene, 8-methyltetracyclo [4.4]. .0.12, 5.17,10] -3-dodecene, 8,9-dimethyltetracyclo [4.4.0.12,5.17,10] -3-dodecene and other C8-30 tetracycloalkenes Tetracyclic olefins such as (eg, C10-35 pentacycloalkadiene such as tricyclopentadiene); eg, hexacycloalkenes (eg, hexacycloalkene [6.). Hexocyclic olefins such as C12-40 hexacycloalkene) such as 6.1.13, 6.02, 7.09, 14] -4-heptadecene) can be mentioned.

These cyclic olefins can be used alone or in combination of two or more. Of these cyclic olefins, polycyclic olefins such as norbornenes are preferable. It is more preferable that the cyclic olefin resin has a polycyclic structure.

The cyclic olefin resin may be a cyclic olefin alone or a copolymer (for example, a copolymer of a monocyclic olefin and a polycyclic olefin), or a cyclic olefin and a copolymerizable monomer. It may be a copolymer.

The copolymerizable monomer is not particularly limited as long as it can be copolymerized, but the alkene (for example, ethylene, propylene, 1-butene, 1-pentene, 1-hexene, 3-methyl-1-butene, 2-methyl) is not particularly limited. -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-ethyl-1-hexene, 1-octene, 1-decene, 1-dodecene, 1-tetradecene, 1-hexadecene, 1-octadecene, 1-eicosene and other C2-20 alkenes), Chain olefins such as alkazines (eg, non-conjugated C5-20 alkanenes such as 1,4-hexadiene, 4-methyl-1,4-hexadiene, 5-methyl-1,4-hexadiene, 1,7-octadiene) and the like. Can be exemplified. These copolymerizable monomers can be used alone or in combination of two or more.
Copolymerizable monomers are α-olefins (eg, C2-10α-olefins such as ethylene, propylene, 1-butene, 1-pentene, 1-hexene, especially C2-6α-olefins). May be good.

Further, as a copolymerizable monomer, a polymerizable nitrile compound (for example, (meth) acrylonitrile, etc.) and a (meth) acrylic monomer (for example, (meth) acrylic) are used as long as the object of the present invention is not impaired. Methyl acid, (meth) acrylic acid esters such as ethyl (meth) acrylate, (meth) acrylic acid, etc.), unsaturated dicarboxylic acids or derivatives thereof (maleic anhydride, etc.), vinyl esters (eg, vinyl acetate, etc.) (Vinyl propionate, etc.), conjugated dienes (butadiene, isoprene, etc.) and the like may be used. These copolymerizable monomers may also be used alone or in combination of two or more.

The cyclic olefin resin is a copolymer of a cyclic olefin and a chain olefin, or a resin containing a polycyclic olefin (for example, 2- to hexacyclic olefin) as a polymerization component, particularly a polycyclic olefin (for example, for example). It may be a copolymer of α-olefin and a monomer having a norbornene skeleton such as the norbornenes and the dicyclopentadiene. In particular, a copolymer of a cyclic olefin and a chain olefin (for example, a polymer of an α-C2-4 olefin such as a copolymer of ethylene and a monomer having a norbornene skeleton and a polycyclic olefin). Can obtain a high molecular weight polymer by having the properties of an olefin polymer (such as an ethylene polymer) and a cyclic olefin polymer and adjusting the copolymerization ratio of the chain olefin.

When the cyclic olefin resin (A) is a copolymer of the cyclic olefin (X) and the chain olefin (Y), the copolymerization ratio (X: Y) is 99: 1 to 1:99 in molar ratio. It is preferably in the range, more preferably 95: 5: 10 to 90, even more preferably 90: 10 to 20:80, and particularly preferably 85: 15 to 30:70, 80. : 20 to 40:60 is particularly preferable. As long as the copolymerization ratio of the cyclic olefin and the chain olefin is within such a range, the balance between melt moldability and heat resistance tends to be excellent.

The cyclic olefin resin may be a resin obtained by addition polymerization or a resin obtained by ring-opening polymerization such as ring-opening metathesis polymerization. In ring-opening polymerization, it is preferable to open a polycyclic olefin, and it is preferable to open a ring of three or more rings such as tetracyclododecene. Further, the cyclic olefin resin (for example, a resin obtained by ring-opening metathesis polymerization) may be a hydrogenated resin. Further, the cyclic olefin resin may be a crystalline or amorphous resin, and may be usually 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 Cheegler type catalyst, addition polymerization using a metallocene-based catalyst, ring-opening metathesis polymerization using a metathesis polymerization catalyst, and the like.

The glass transition temperature of the cyclic olefin resin (A) is preferably 140 ° C. or higher and 200 ° C. or lower, more preferably 145 ° C. or higher and 195 ° C. or lower, and 150 ° C. or higher and 190 ° C. or lower. Further preferably, it is particularly preferably 155 ° C. or higher and 185 ° C. or lower, and particularly preferably 160 ° C. or higher and 180 ° C. or lower. Within the range where the glass transition temperature of the cyclic olefin resin (A) is applied, the balance between melt moldability and heat resistance tends to be excellent.

_{The tensile storage elastic modulus (E 20} ) of the cyclic olefin resin (A) at 20 ° C. is preferably 2000 MPa or more. When the elastic modulus (E ₂₀ ) of the cyclic olefin resin (A) is 2000 MPa or more, the elastic modulus of the entire resin composition is kept within the desired range described later, and the folding resistance of the film made of the resin composition is increased. This makes it easier to improve impact resistance.
_{The tensile storage elastic modulus (E 20} ) of the cyclic olefin resin (A) at 20 ° C. is more preferably 2150 MPa or more, further preferably 2300 MPa or more, and preferably 5000 MPa or less, more preferably 4000 MPa or less, still more preferable. Is 3000 MPa or less.
Tensile storage modulus at 20 ° C. of the cyclic olefin resin _{(A) (E 20)} and 100 the ratio of the tensile storage modulus at _{℃ (E 100) (E 100} / E 20) is 0.5 or more, is 1 or less It is more preferable, it is more preferably 0.6 or more and 0.95 or less, and further preferably 0.7 or more and 0.9 or less. As long as the cyclic olefin resin (A) E ₁₀₀ / E ₂₀ is applied, a practically usable resin makes it easy to reduce the change in elastic modulus due to the temperature change of the resin composition.

The cyclic olefin resin (A) may be polymerized by the above method, or a commercially available one may be used. Examples of commercially available products include "Zeonor" and "Zeonex" manufactured by Zeon Corporation, "Arton" manufactured by JSR Corporation, "Apel" manufactured by Mitsui Chemicals, and "TOPAS" manufactured by Polyplastics Corporation.

[Styrene-based copolymer (B)]
The styrene-based copolymer (B) used in the present invention is a copolymer of styrene and other components. The copolymerizing component is not particularly limited, but it is preferable that the component itself functions as a soft segment and forms an elastomer having styrene as a hard segment. Specifically, it is preferably at least one soft segment 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 is composed of a hard block composed of styrene and one or more of the copolymerization components constituting the soft segment. It is preferable to provide a soft block.

Specific examples of the styrene-based copolymer (B) include a styrene-butadiene copolymer (SB), a styrene-butadiene-styrene copolymer (SBS), a styrene-isoprene copolymer (SI), and a styrene-isoprene-. Styrene copolymer (SIS), styrene-isobutylene copolymer (SIB), styrene-isobutylene-styrene copolymer (SIBS), styrene-butadiene-butylene-styrene copolymer (SBBS), styrene-ethylene-butylene- Examples thereof include a styrene copolymer (SEBS), a styrene-ethylene-propylene-styrene copolymer (SEPS), and a styrene-ethylene-ethylene-propylene-styrene (SEEPS) copolymer. Above all, from the viewpoint of dispersibility and flexibility in the cyclic olefin resin (A) and a 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, and specifically, isobutylene. SIB and SIBS, which are copolymers with SIB, are preferable, and SIBS is more preferable. Each of the copolymers described as the above specific examples may be a block copolymer, for example, SIB may be a diblock copolymer and SIBS may be a triblock copolymer.

The ratio of the styrene component contained in the styrene-based 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, and 5% by mass. As mentioned above, it is more preferably 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. As long as the ratio of the styrene component is within the range, the elastic modulus does not easily 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 temperature to high temperature can be reduced. It becomes easy to maintain the elastic modulus ratio (E ₁₀₀ / E ₂₀ ) of the resin composition at a large value.

The mass average molecular weight of the styrene-based copolymer (B) is, for example, 50,000 or more and 300,000 or less, but preferably 70,000 or more and 260000 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 it becomes easy to maintain _{the elastic modulus ratio (E 100} / E _{20) of the resin composition at a large value.} Further, when it is set to 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 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 the mass average molecular weight converted to the standard polystyrene molecular weight of the gel permeation chromatography method, and can be measured under the following conditions, for example.
Equipment: Tosoh HLC-8320GPC
Column: 4 connected
Shim-pack GPC-806C
Shim-pack GPC-804C
Shim-pack GPC-8025C
Shim-pack GPC-801C
Length 300 mm, inner diameter 8.0 mm
Eluent: Chloroform flow rate: 1 ml / min
Detector: RI
Column constant temperature bath temperature: 40 ° C
Sample concentration: Approximately 0.3% by mass (20 mg / 4 ml)
Injection volume: 20 μl

_{The tensile storage elastic modulus (E 20} ) of the styrene-based copolymer (B) at 20 ° C. is preferably 30 MPa or less. By setting the tensile storage elastic modulus (E ₂₀ ) of the styrene-based copolymer (B) to 30 MPa or less, the elastic modulus of the entire resin composition is maintained within the above range, and the film made of the resin composition is resistant to folding. It becomes easier to improve the impact resistance by increasing the strength. From these viewpoints, the tensile storage elastic modulus (E ₂₀ ) of the styrene-based copolymer (B) is more preferably 20 MPa or less, further preferably 15 MPa or less, particularly preferably 10 MPa or less, and particularly preferably 5 MPa or less. Is. Further, it is preferably 0.1 MPa or more, more preferably 0.5 MPa or more, still more preferably 1 MPa or more.
Further, the ratio E ₁₀₀ / E ₂₀ of the tensile storage elastic modulus E _{20 at 20} ° C. and the tensile storage elastic modulus E ₁₀₀ at 100 ° C. of the styrene copolymer (B) is, for example, 0.1 or more and 1.1 or less. However, it is 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. _{As long as E 100} / E _{20 of the} styrene-based copolymer (B) is applied, the change in elastic modulus due to the temperature change of the resin composition can be easily reduced by the resin that can be practically used.

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 effects of the present invention are not impaired. Specific examples of the other resin component (C) include polyethylene, polypropylene, polyvinyl chloride, polystyrene, polyvinylidene chloride, polyvinyl alcohol, ethylene-vinyl alcohol copolymer, polymethylpentene, polyphenylene ether, polyethylene terephthalate, and poly. Butylene terephthalate, polyacetal, aliphatic polyamide, polymethylmethacrylate, polycarbonate, ABS, polyphenylene sulfide, aromatic polyamide, polyarylate, polyetherimide, polyphenylsulphon, polyetherimidesalphon, polyetherketone, polyetheretherketone , Polyetherketoneketone, polyetherketoneetherketoneketone, polyetheretherketoneketone, polyamideimide, polysalphon, polyethersalphon, liquid crystal polymers, or copolymers thereof, or mixtures thereof. When the other resin component (C) is further contained, the content of the other resin component (C) is preferably 0.1% by mass or more, preferably 0.3% by mass or more in the resin composition. Is more preferable, 0.5% by mass or more is further preferable, 1% by mass or more is particularly preferable, and 3% by mass or more is particularly preferable. Further, it is preferably 10% by mass or less, more preferably 9% by mass or less, further preferably 8% by mass or less, particularly preferably 7% by mass or less, and 5% by mass or less. It is especially preferable to have. When the other resin component (C) is further contained, if the content ratio is within such a range, a necessary effect can be appropriately imparted while maintaining the effect of the present invention.

The resin composition according to the second aspect is a heat stabilizer, an antioxidant, an ultraviolet absorber, a light stabilizer, an antibacterial / antifungal agent, an antistatic agent, a lubricant, a pigment, as long as the effect of the present invention is not impaired. , Dyes and other additives may be included.

_{The tensile storage elastic modulus (E 20} ) of the resin composition according to the second aspect at 20 ° C. is preferably 1 MPa or more and 1100 MPa or less, more preferably 10 MPa or more and 1050 MPa or less, and 100 MPa or more and 1000 MPa or less. It is more 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 elastic modulus at 20 ° C. is within the range, excellent acoustic characteristics can be obtained even when used for acoustic members, especially diaphragms for electroacoustic converters, which have been miniaturized in recent years, while maintaining handleability during molding. It becomes easy to be.

_{The tensile storage elastic modulus (E 100} ) of the resin composition according to the second aspect at 100 ° C. is preferably 1 MPa or more and 1100 MPa or less, more preferably 10 MPa or more and 1050 MPa or less, and 100 MPa or more and 1000 MPa or less. It is more preferably 150 MPa or more and 900 MPa or less, and particularly preferably 200 MPa or more and 800 MPa or less. When the tensile storage elastic modulus at 100 ° C. of the resin composition is within such a range, the heat resistance is likely to be excellent while maintaining the handleability at the time of molding.

The ratio (E ₁₀₀ / E ₂₀ ) of the tensile storage elastic modulus (E ₂₀ ) at 20 ° C. to the tensile storage elastic modulus (E ₁₀₀ ) at 100 ° C. according to the second aspect is 0.5 or more. It is preferably 2 or less, more preferably 0.55 or more and 1.1 or less, further preferably 0.6 or more and 1 or less, and 0.65 or more and 0.97 or less. Is particularly preferable, and 0.7 or more and 0.95 or less are particularly preferable. Within the range where E ₁₀₀ / E ₂₀ is applied, the moldability is maintained and the change in elastic modulus is small, so that the heat resistance is excellent. Therefore, it is easy to prevent deterioration of sound quality in a high temperature environment and to improve sound reproduction from a low temperature range to a high temperature range.

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. Within such a range, the influence of water absorption on sound quality can be reduced. 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.

(Manufacturing method of resin composition)
The method for producing the resin composition for an acoustic member in each embodiment is not particularly limited, and for example, it can be obtained by melt-kneading the materials constituting the resin composition for an acoustic member. As the kneader for melt kneading, an extruder such as a single-screw or twin-screw extruder or a known kneader such as a plast mill 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, whereby the resin composition having a desired tensile storage elastic modulus can be adjusted. It becomes easy to get things.
The melting temperature is appropriately adjusted according to the type and mixing ratio of the resin and the presence and type of additives, but from the viewpoint of productivity and the like, it is preferably 230 ° C. or higher, and more preferably 240 ° C. or higher. It is preferably 250 ° C. or higher, and 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. As long as the melting temperature is within the range, it becomes easy to sufficiently flow the resin while suppressing decomposition and cross-linking of the resin.

As the kneader, L / D, which is the ratio of the screw length L (mm) to the diameter D (mm) of the screw, is preferably 15 or more, more preferably 20 or more, preferably 50 or less, and more preferably 40. The extruder below is preferred. By setting such a ratio to 15 or more, it becomes easy to improve the dispersibility of the resin component and obtain a resin composition having a desired tensile storage elastic modulus, and by setting such a ratio to 50 or less, the resin residence time becomes long. When the resin becomes too high or the resin temperature becomes too high, it tends to be easy to suppress the generation of discoloration, outgas, gel-like foreign matter, etc. due to thermal deterioration.
As the screw configuration of the extruder, a structure having a kneading unit, particularly a spiral kneading unit, is preferable in order to improve kneading property. The kneading unit is preferably one or two places.

The ratio Q / Ns of the discharge amount Q (kg / hr) and the screw rotation speed Ns (rpm) at the time of melt-kneading is preferably 0.01 or more, more preferably 0.05 or more, preferably 10 or less, and more. It is preferably 5 or less. By setting this value in the above range, the discoloration of the resin composition and the generation of foreign substances due to the resin temperature becoming too high or the residence time becoming too long are suppressed, and the dispersibility of each resin component is improved. This makes it easy to obtain a resin composition having a desired tensile storage elastic modulus.

Further, as the kneading machine, a continuous kneading machine is also preferably used. In a continuous kneader, a screw that is rotatably mounted in the cylinder of an extruder is provided with a plurality of rotary blades, and a fixed blade is inserted between the plurality of rotary blades. It is a kneading machine installed in the cylinder. When the screw rotates, the raw material that moves along the screw shaft is sent in a zigzag manner, such that the gap formed between the rotating blade and the fixed blade is sent from the center side to the outer peripheral side, and further from the outer peripheral side to the center side. Since it passes through and is kneaded, it is possible to efficiently apply the three actions of compression, shearing, and substitution to the raw material, and it is possible to improve the dispersibility of each component more effectively than with a single-screw or twin-screw extruder. can. The shape of the blade is not particularly limited, and for example, a fan-shaped, chrysanthemum-shaped, or mortar-shaped blade can be used. Examples of such a continuous kneader include the "NES / KO series" manufactured by Chemical Engineering Co., Ltd.

[Film for acoustic members]
The film for an acoustic member of the present invention (hereinafter, may be referred to as “the film”) is the resin composition for an acoustic member according to the first embodiment or the resin composition for an acoustic member according to the second embodiment. It is a film consisting of.

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, further preferably 3 μm or more and 35 μm or less, and 4 μm or more and 20 μm or less. Especially preferable. As long as it is thick, the balance between handleability and sound quality is excellent, and it tends to contribute to the miniaturization and space saving of the diaphragm.

(Film manufacturing method)
The film can be produced by a general molding method, for example, extrusion molding, injection molding, blow molding, vacuum molding, pressure molding, press molding or the like. 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 preferable. Further, the resin composition extruded by the T-die may be taken up by, for example, a cast roll.

The method for producing a film of the present invention is not particularly limited, but for example, it can be obtained by molding a film constituent material (that is, a resin composition) as a non-stretched or stretched film, and from the viewpoint of secondary processability, it can be obtained. It is preferably obtained as a non-stretched film. The non-stretched film is a film that is not actively stretched for the purpose of controlling the orientation of the sheet, and includes a film that is oriented when it is taken up by a cast roll by the T-die method.

For example, it can be produced by melt-kneading each constituent material to obtain a resin composition, then extruding the resin composition and cooling it. For melt kneading, a known kneader such as a single-screw or twin-screw extruder or a plast mill can be used. The details of melt-kneading are as described above.
Molding can be performed, for example, by extrusion molding using a mold such as a T-die, and it is preferable to cool using a cast roll.

The temperature of the cast roll is preferably 50 ° C. or higher, more preferably 100 ° C. or higher, and even more preferably 120 ° C. or higher. As long as the lower limit of the cast roll temperature is applied, the film has excellent adhesion to the film, is less likely to wrinkle due to quenching, and is easy to obtain a film having a good appearance.
On the other hand, the temperature of the cast roll is preferably 200 ° C. or lower, more preferably 190 ° C. or lower, and even more preferably 180 ° C. or lower. As long as the upper limit of the temperature of the cast roll is applied, the film sticks to the roll, and the sticking marks generated when the film is separated from the roll are less likely to occur, and a film having a good appearance can be easily obtained. It is also preferable to use a touch roll or an electric contact device in order to improve the adhesion between the cast roll and the film.

Further, in the case of a non-stretched film, for example, each component constituting the resin composition may be melt-kneaded at the above melting temperature to obtain a resin composition, and the resin composition may be press-molded into a film.

[Usage / Usage]
Since the film for an acoustic member of the present invention has excellent heat resistance, has an elastic modulus in a specific range, and has a small change in elastic modulus from low temperature to high temperature, it can be suitably used as a diaphragm for an acoustic member, particularly an acoustic member. can.
Specifically, the film for an acoustic member of the present invention can be used for various electroacoustic converters such as a speaker, a receiver, a microphone, and an earphone. Among these, a speaker diaphragm is more preferable, and a portable speaker is particularly portable. It can be suitably used as a microspeaker diaphragm for telephones and the like.

The film for an acoustic member is appropriately secondary processed and formed into various acoustic members such as a diaphragm for an acoustic member, and is preferably formed into a diaphragm for an electroacoustic converter, particularly preferably a speaker diaphragm.
As for the film for an acoustic member, for example, at least a part of the film may be processed into a dome shape or a cone shape. Further, the surface of the film may be provided with a tangential edge. When processed into a dome shape or a cone shape, or when a tangential edge is imparted, it is preferably used for a diaphragm for an acoustic member, and more preferably for 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 the softening temperature of the film, and to form the film by press molding, vacuum forming, or the like.

(Diaphragm for acoustic members)
Explaining the diaphragm for acoustic members in more detail, the shape of the diaphragm is not particularly limited and is arbitrary, and a circular shape, an elliptical shape, an oval shape, or the like can be selected. Further, the diaphragm for an acoustic member generally has a body that vibrates in response to an electric signal or the like, and an edge that surrounds the body. The body of the diaphragm is usually supported by the edges. The shape of the diaphragm may be a dome shape or a cone shape as described above, a shape obtained by combining these, or another shape used for the diaphragm.

The acoustic member film of the present invention may form at least a part of the acoustic member diaphragm. For example, the body or edge of the diaphragm is formed by the acoustic member film 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 of the film for the acoustic member of the present invention, or the entire diaphragm for the acoustic member may be formed of the film for the acoustic member.

FIG. 1 is a diagram showing a structure of a diaphragm 1 according to an embodiment of the present invention, and is a cross-sectional view of a circular diaphragm 1 cut along a plane passing through the center line of a circle in a plan view. As shown in FIG. 1, the diaphragm 1 is centered on the dome portion (body) 1a, the concave fitting portion 1b attached to the voice coil 2, the peripheral edge portion (edge) 1c, and the outer periphery to be attached to the frame or the like. It has a sticking portion 1d. The diaphragm 1 is formed by the film for an acoustic member of the present invention.

FIG. 2 is a diagram showing the structure of the diaphragm 11 in 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 a circle in a plan view. As shown in FIG. 2, the microspeaker diaphragm 11 is centered on a dome portion (body) 11a processed into a dome shape, a concave fitting portion 11b attached to the voice coil 2, and a cone portion 11j processed into a cone shape. It also has a peripheral edge (edge) 11c. As illustrated in the diaphragm 11, a part of the diaphragm may be processed into a dome shape, and a part other than the part may be processed into a cone shape. The peripheral portion 11c of the microspeaker diaphragm 11 may be directly attached to the frame or the like, or may be attached to the frame or the like via another member.

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

As described above, the diaphragm is preferably a speaker diaphragm, particularly a micro speaker diaphragm. From the viewpoint of preferably using the diaphragm as a microspeaker diaphragm, the diaphragm has a maximum diameter of 25 mm or less, preferably 20 mm or less, and a diaphragm having a maximum diameter of 5 mm or more is preferably used. The maximum diameter is defined as the diameter when the diaphragm has a circular shape, and the major diameter when the diaphragm has an elliptical shape or an oval shape.

The diaphragm may be formed of the acoustic member film of the present invention alone, or may be formed of a composite material of the acoustic member film of the present invention and another member. For example, as described above, either the edge or the body may be formed of other members. Further, it may be composed of a laminated body of a film for an acoustic member and another layer.

The laminate may have, for example, the above-mentioned film for an acoustic member and an adhesive layer provided on at least one surface of the film for an acoustic member. The laminated body tends to have good damping characteristics by having an adhesive layer.
Further, the laminated body is preferably a laminated body in which the above-mentioned film for an acoustic member is used as a front and back layer and an adhesive layer is used as an intermediate layer. With such a laminated structure, in addition to the heat resistance, impact resistance, and moldability of the film for the acoustic member of the front and back layers, the excellent damping characteristics of the intermediate layer can be imparted to the laminated body. The method for producing the diaphragm composed of such a laminated body is not particularly limited. For example, a method of secondary processing a pair of films for acoustic members to prepare molded bodies constituting a surface layer and a back layer, respectively, and adhering them via an adhesive used for an intermediate layer, or a method of producing the same. Examples thereof include a method in which a pair of films for acoustic members are adhered to each other via an adhesive used for an intermediate layer to produce a laminated film, and the laminated film is secondarily processed.
In this case, the thicknesses of the surface layer and the back layer are preferably 1 μm or more and 30 μm or less, more preferably 2 μm or more and 25 μm or less, and further 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 further 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 increased, it is easy to obtain a diaphragm having excellent damping characteristics while maintaining various mechanical properties and moldability.

In addition to the above-mentioned film for acoustic members and the adhesive layer, the laminate may include a resin film other than the above-mentioned film for acoustic members. Resin components used in the resin film include polyetheretherketone resin (PEEK), polyester elastomer (TPEE), polyetherimide resin, polyurethane resin, polyvinylphenyl ether sulfone resin (PPSU), crystalline polyimide resin, and fat. Examples thereof include group polyamide resins, semi-aromatic polyamide resins and mixtures thereof.
When a resin film other than the film for the acoustic member is provided, one of the front and back layers is a film for the acoustic member, the other of the front and back layers is a resin film other than the film for the acoustic member, and the adhesive layer is an intermediate layer. Laminated body, film for acoustic member / resin film other than film for acoustic member / laminate in the order of adhesive layer, film for acoustic member / resin film other than film for acoustic member / adhesive layer / film for acoustic member Examples thereof include a laminated body in which a resin film other than the above and a film for an acoustic member are laminated in this order.

The adhesive layer used for the laminate may be formed of an adhesive. Examples of the type of adhesive used for the adhesive layer include acrylic adhesive, rubber adhesive, silicone adhesive, urethane adhesive, etc., but from the viewpoint of adhesiveness, acrylic or silicone adhesive Is preferably used.

Further, in order to adjust the secondary processing suitability and dustproofness of the diaphragm, adjust the acoustic characteristics, improve the design, etc., an antistatic agent and various elastomers (antistatic agents and various elastomers) are further applied to the surface of the film for acoustic members or the molded diaphragm of the present invention. For example, even if treatments such as coating or laminating urethane-based, silicone-based, hydrocarbon-based, fluorine-based, etc., depositing metal, sputtering, or coloring (black, white, etc.) are performed as appropriate. good. Further, it may be laminated with a metal such as aluminum or another film, or composited with a non-woven fabric as appropriate.
When laminated with other films, the other films include polyether ether ketone, polyester elastomer, thermoplastic polyurethane, polybiphenyl ether sulfone resin (PPSU), crystalline polyimide resin, aliphatic polyamide resin, and semi-aromatic. A film made of a polyamide resin or a resin such as a mixture thereof is preferable from the viewpoint of tensile storage elasticity, heat resistance, and secondary processability.

Hereinafter, the present invention will be described in detail with reference to Examples, but the present invention is not limited thereto.

1. 1. Production of Resin Composition and Film In Examples and Comparative Examples, the resin composition and film having the compounding composition shown in Table 2 were produced using the raw materials shown in Table 1 below.

(Example 1)
A dry blend of (A) -1: (B) -1 = 60: 40 (mass ratio) was used as a raw material, and was put into a lab plast mill manufactured by Toyo Seiki Seisakusho Co., Ltd. and melted while kneading. At this time, the temperature of the apparatus was 260 ° C., the rotation speed was 60 rpm, and the kneading time was 10 minutes. The resin composition thus prepared was hot-pressed at 260 ° C. to prepare an unstretched film having a thickness of 100 μm.

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

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

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

(Example 6)
A dry blend of (A) -2: (B) -1 = 40: 60 (mass ratio) was put into a twin-screw extruder (L / D = 38) equipped with a screw of Φ25 mm, and the temperature was 250 ° C. It was melted while kneading at 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 on a cast roll at 120 ° C. to prepare an unstretched film having a thickness of 100 μm.

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

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

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

(Comparative Example 2)
A film was prepared in the same manner as in Example 1 except that (A) -2 was used alone.

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

(Comparative Example 4)
Polyetherimide ((C) -1) is put into a single-screw extruder equipped with a screw of φ40 mm, melted while kneading at a temperature of 380 ° C. and a rotation speed of 30 rpm, and extruded at an extrusion temperature of 380 ° C. using a T-die. Extruded. The extruded resin was taken up by a cast roll at 230 ° C. to prepare an unstretched film having a thickness of 100 μm.

(Comparative Example 5)
Polyetheretherketone ((C) -2) is put into a single-screw extruder equipped with a screw having a diameter of 40 mm, melted while kneading at a temperature of 380 ° C. and a rotation speed of 30 rpm, and the extrusion temperature is 380 ° C. using a T-die. Extruded with. The extruded resin was taken up by a cast roll at 230 ° C. to prepare an unstretched film having a thickness of 100 μm.

(Comparative Example 6)
Polyamide 9T ((C) -3) was put into a single-screw extruder equipped with a screw having a diameter of 40 mm, melted while kneading at a temperature of 320 ° C., and extruded at an extrusion temperature of 320 ° C. using a T-die. The extruded resin was taken up by a cast roll at 120 ° C. to prepare an unstretched film having a thickness of 100 μm.

2. Evaluation and Measurement Method The resin compositions and films in the above Examples and Comparative Examples were evaluated and measured for various items as follows.

(1) Tension storage elastic modulus A test piece (thickness 100 μm) of 5 mm × 8 cm was cut out from the films obtained in each Example and Comparative Example, and obtained as a measurement sample. Using the measurement sample, using the viscoelastic spectrometer "DVA-200 (manufactured by IT Measurement Control Co., Ltd.)" in accordance with JIS K7244-4: 1999, frequency 10 Hz, strain 0.1%, temperature range The temperature was raised at 20 to 400 ° C. and a heating rate of 3 ° C./min, and the tensile storage elastic modulus (E ₂₀ , E ₁₀₀ ) at 20 ° C. and 100 ° C. was measured.
Since the extruded films of Examples 6 to 8 and Comparative Example 5 are directional, measurements are taken in the vertical direction (direction in which the resin composition is extruded from the T die (MD)) and the horizontal direction (TD) of the film. Then, the average value was taken as the tensile storage elastic modulus. In Comparative Examples 4 and 6, since MD has not been measured, the value of TD is shown as a reference value.

(2) Tensile at 20 ° C. storage elastic modulus _{(E 20)} and the tensile storage modulus at 100 ° C. The ratio of _{(E 100) (E 100 /} E 20)
_{E 100} / E ₂₀ was calculated from each value obtained by the measurement of (1).

(3) Water Absorption A test piece (thickness 100 μm) of 10 cm × 10 cm was cut out from the films obtained in each Example and Comparative Example and obtained as a measurement sample.
According to JIS K7029: 2000, the obtained measurement sample was immersed in water for 24 hours at 23 ° C., and the water absorption rate was measured from the mass change before and after immersion.

Table 2 below summarizes the evaluation and measurement results of Examples 1 to 8 and Comparative Examples 1 to 6.

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

On the other hand, the resin compositions used in Comparative Examples 1 to 6 have a high elastic modulus, and are presumed to be inferior in sound quality, especially sound quality and reproducibility at low temperatures, when used as a diaphragm, for example. Further, since the super engineering plastics having high polarity are used in Comparative Examples 4 to 6, it is presumed that the water absorption rate is high and the humidity has a great influence on the sound quality and reproducibility.
Further, from the studies so far by the present inventor, it is inferred that the resin compositions of Examples 1 to 8 are also excellent in impact resistance such as folding strength.

Claims (29)

Tensile storage modulus at ₂₀ ℃ _(E 20) is not more than 1100 MPa, the tensile storage modulus at ₂₀ ℃ _(E 20) and the tensile storage modulus at 100 ° C. The ratio of the _{(E 100) (E 100 /} E 20) A resin composition for an acoustic member having a value of 0.5 or more and 1.2 or less. Wherein is the ratio of the tensile storage modulus at ₂₀ ℃ _(E 20) and the tensile storage modulus at _{100 ℃ (E 100) (E} 100 / E 20) is 0.5 or more and 1 or less, the acoustic of claim 1 Resin composition for members. Tensile storage modulus at 20 ° C. and _{(E 20)} is not less than 2000MPa resin (a), and a resin (b) is tensile at 20 ° C. storage elastic modulus _{(E 20)} is 50MPa or less, according to claim 1 or 2. The resin composition for an acoustic member according to 2. The ratio of resin tensile storage modulus at 20 ° C. of _{(b) (E 20)} and the tensile storage modulus at _{100 ℃ (E 100) (E} 100 / E 20) is 0.1 to 1.1, The resin composition for an acoustic member according to claim 3. The ratio _(E 100 _/ E ₂₀₎ is 0.5 or more and 1 or less of the tensile storage modulus at 20 ° C. of the resin _{(a) (E 20)} and the tensile storage modulus at ₁₀₀ ℃ _(E 100), claim The resin composition for an acoustic member according to 3 or 4. The resin composition for an acoustic member according to any one of claims 3 to 5, wherein the glass transition temperature of the resin (a) is 140 ° C. or higher and 200 ° C. or lower. The resin composition for an acoustic member according to any one of claims 3 to 6, wherein the resin (b) has a mass average molecular weight of 50,000 or more and 300,000 or less. The resin composition for an acoustic member according to any one of claims 3 to 7, wherein the resin (a) is a cyclic olefin resin (A). The resin composition for an acoustic member according to any one of claims 3 to 8, wherein the resin (b) is a styrene-based copolymer (B). A resin composition for an acoustic member containing a cyclic olefin resin (A) and a styrene copolymer (B). The resin composition for an acoustic member according to claim 10, wherein the tensile storage elastic modulus (E _{20) at 20 ° C. is 1 MPa or more and 1100 MPa or less.} The resin composition for an acoustic member according to claim 10 or 11, wherein the tensile storage elastic modulus (E _{100) at 100 ° C. is 1 MPa or more and 1100 MPa or less.} Tensile storage modulus at ₂₀ ℃ _(E 20) and the tensile storage modulus at ₁₀₀ ℃ _(E 100) the ratio of the _(E 100 _/ E ₂₀₎ is 0.5 to 1.2, according to claim 10 to 12 The resin composition for an acoustic member according to any one of the above items. The resin composition for an acoustic member according to any one of claims 10 to 13, wherein the glass transition temperature of the cyclic olefin resin (A) is 140 ° C. or higher and 200 ° C. or lower. The resin composition for an acoustic member according to any one of claims 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. The resin composition for an acoustic member according to any one of claims 8 to 15, wherein the cyclic olefin resin (A) contains at least a polycyclic olefin as a polymerization component. Claims 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 isoprene. The resin composition for an acoustic member according to any one of the above items. The resin composition for an acoustic member according to any one of claims 9 to 17, wherein the proportion of the styrene component contained in the styrene-based copolymer (B) is 1% by mass or more and 30% by mass or less. The resin for an acoustic member according to any one of claims 9 to 18, wherein the styrene-based copolymer (B) is a styrene-isobutylene-styrene triblock copolymer or a styrene-isobutyrene block copolymer. Composition. The resin composition for an acoustic member according to any one of claims 1 to 19, wherein the water absorption rate when immersed at 23 ° C. for 24 hours is 0.1% or less. A film for an acoustic member comprising the resin composition according to any one of claims 1 to 20. The film for an acoustic member according to claim 21, wherein at least a part thereof is processed into at least one of a dome shape and a cone shape. The film for an acoustic member according to claim 21 or 22, wherein the surface is provided with a tangential edge. The film for an acoustic member according to any one of claims 21 to 23, which is used for a diaphragm for an electroacoustic converter. A laminate having an acoustic member film according to any one of claims 21 to 24 and an adhesive layer provided on at least one surface of the acoustic member film. A diaphragm for an acoustic member obtained by molding the film for an acoustic member according to any one of claims 21 to 24 or the laminate according to claim 25. The diaphragm for an acoustic member according to claim 26, which is a speaker diaphragm. A method of using the film for an acoustic member according to any one of claims 21 to 24 or the laminate according to claim 25 as an acoustic member. Use of the film for an acoustic member according to any one of claims 21 to 24, or the laminate according to claim 25 as an acoustic member.

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