Film for diaphragm, diaphragm for acoustic apparatus, acoustic apparatus, and electronic apparatus

Abstract

To provide a film for a diaphragm which is excellent in low-temperature characteristics, heat resistance and flexibility and has a feature that a change in flexibility from a low temperature to a high temperature is small.SOLUTION: The film for a diaphragm uses a polycarbonate resin composition which contains a carbonate structural unit (X) derived from an aliphatic dihydroxy compound (1) represented by the following formula (1) and a carbonate structural unit (Y) derived from a dihydroxy compound (2) satisfying the following requirement I and which has a melting point peak temperature as measured by a differential scanning calorimeter. <Requirement I> A polycarbonate resin (2) obtained by polymerizing the dihydroxy compound (2) and a carbonate source by a transesterification method has a melting point peak temperature as measured by a differential scanning calorimeter. (X and Y are each a single bond or a divalent liking group comprising 1-15 carbon atoms, 0-6 oxygen atoms and 2-30 hydrogen atoms and having no cyclic structure; and n is 2-100.)SELECTED DRAWING: None

Description

[Technical Field]

[0001] The present invention relates to a diaphragm film that has excellent low-temperature properties (low-temperature mechanical strength), heat resistance, and flexibility, and exhibits small changes in elastic modulus, an index of flexibility, from low to high temperatures; a diaphragm for an acoustic device that uses this diaphragm film; an acoustic device that has this diaphragm for an acoustic device; and an electronic device that has this acoustic device. [Background technology]

[0002] Polycarbonate resin has excellent mechanical strength, electrical properties, transparency, etc., and is widely used as an engineering plastic in various fields such as electrical and electronic equipment and automobiles. However, unlike polyester-based thermoplastic elastomers and thermoplastic polyurethanes, there are currently few polycarbonate resins used as elastomers. Therefore, the development of polycarbonate-based thermoplastic elastomers may lead to further expansion of applications.

[0003] In recent years, speaker diaphragms have been required to be flexible, and rubber and thermoplastic elastomers have been attracting attention. Furthermore, because speakers reach high temperatures during use, heat resistance is required. Furthermore, to maintain high sound quality at operating temperatures, the material must have a small change in elastic modulus from low to high temperatures.

[0004] Patent Document 1 proposes a sheet for speaker diaphragms that is made of aramid nanofibers and is lightweight, has high rigidity, and a high loss tangent value. However, the sheet for speaker diaphragms in Patent Document 1 has the disadvantage of being poor in flexibility.

[0005] On the other hand, concerns about global warming due to the depletion of petroleum resources and increased carbon dioxide emissions have led to a demand for the development of plastics made from carbon-neutral plant-derived monomers. Under these circumstances, Patent Document 2 discloses a polycarbonate resin that uses a compound produced from a plant-derived raw material and has excellent flexibility, color, and thermal stability, and a polycarbonate resin composition that uses the polycarbonate resin as an impact modifier and has excellent impact resistance and heat resistance. Patent Document 2 specifically proposes a copolymer polycarbonate resin that uses polytrimethylene ether glycol (hereinafter sometimes abbreviated as "PO3G") and isosorbide. [Prior art documents] [Patent documents]

[0006] [Patent Document 1] Japanese Patent Publication No. 2022-17796 [Patent Document 2] Patent Publication No. 2021-91900 Summary of the Invention [Problem to be solved by the invention]

[0007] Although the copolymer polycarbonate resin of Patent Document 2 has excellent flexibility, the copolymerization of polytrimethylene ether glycol significantly lowers the glass transition temperature and reduces heat resistance, making it difficult to use for diaphragms, which require heat resistance.

[0008] The object of the present invention is to provide a film for diaphragms that has excellent low-temperature properties (low-temperature mechanical strength), heat resistance, and flexibility, and that exhibits small changes in elastic modulus, which is an indicator of flexibility, from low to high temperatures; a diaphragm for an acoustic device that uses this diaphragm film; an acoustic device that has this diaphragm for an acoustic device; and an electronic device that has this acoustic device. [Means for solving the problem]

[0009] The present inventors have discovered that a film for a diaphragm that meets the above-mentioned objectives can be obtained by using a polycarbonate resin composition that contains carbonate structural units derived from a specific aliphatic dihydroxy compound and carbonate structural units derived from a dihydroxy compound that meets specific requirements, and that has a melting point peak temperature.

[0010] The present invention is summarized as follows [1] to

[15] .

[0011] [1] A film for a diaphragm obtained using a polycarbonate resin composition, the polycarbonate resin composition containing carbonate structural units (X) derived from an aliphatic dihydroxy compound (1) represented by the following formula (1) and carbonate structural units (Y) derived from a dihydroxy compound (2) satisfying the following requirement I, wherein the polycarbonate resin composition has a peak melting point temperature when heated at a temperature rise rate of 20°C / min using a differential scanning calorimeter and measured for the peak melting point temperature. <Requirement I> The polycarbonate resin (2) obtained by polymerizing the dihydroxy compound (2) and a carbonate source by a transesterification method has a peak melting point temperature when the peak melting point temperature is measured by heating at a temperature increase rate of 20°C / min using a differential scanning calorimeter.

[0012] [ka]

[0013] (In formula (1), X and Y are different from each other and each independently represent a single bond or a divalent linking group having 1 to 15 carbon atoms, 0 to 6 oxygen atoms, and 2 to 30 hydrogen atoms and not having a cyclic structure. n is an integer of 2 to 100.)

[0014] [2] The film for diaphragms according to [1], wherein the polycarbonate resin composition contains 1 to 99 mass% of the carbonate structural units (X) and 1 to 99 mass% of the carbonate structural units (Y) relative to 100 mass% of all carbonate structural units.

[0015] [3] The film for diaphragms according to [2], wherein the polycarbonate resin composition contains 40 to 85 mass% of the carbonate structural units (X) and 15 to 60 mass% of the carbonate structural units (Y) relative to 100 mass% of all carbonate structural units.

[0016] [4] The film for a diaphragm according to any one of [1] to [3], wherein the aliphatic dihydroxy compound (1) has a number average molecular weight of 400 or more and 10,000 or less.

[0017] [5] The film for a diaphragm according to any one of [1] to [4], wherein the aliphatic dihydroxy compound (1) is an aliphatic dihydroxy compound represented by the following formula (2):

[0018] [ka]

[0019] (In formula (2), n is an integer of 2 to 100.)

[0020] [6] The film for a diaphragm according to any one of [1] to [5], wherein the dihydroxy compound (2) is any one of the dihydroxy compounds represented by the following formulas (3) to (6):

[0021] [ka]

[0022] [7] The film for a diaphragm according to any one of [1] to [6], wherein the glass transition temperature of the polycarbonate resin composition is −100° C. or higher and 30° C. or lower.

[0023] [8] The film for a diaphragm according to any one of [1] to [7], wherein the polycarbonate resin composition has a peak melting point of 130°C or more and 350°C or less.

[0024] [9] The film for diaphragms according to any one of [1] to [8], wherein the storage modulus E'(-30°C) (unit: MPa) of the polycarbonate resin composition at -30°C as determined by dynamic viscoelasticity measurement is 0.1 or more and 700 or less.

[0025]

[10] The film for diaphragms according to any one of [1] to [9], wherein the storage modulus E'(130°C) (unit: MPa) of the polycarbonate resin composition at 130°C as determined by dynamic viscoelasticity measurement is 0.1 or more and 700 or less.

[0026]

[11] The film for diaphragms according to any one of [1] to

[10] , wherein the ratio E'(130°C) / E'(-30°C) of the storage modulus E'(-30°C) (unit: MPa) at 130°C to the storage modulus E'(-30°C) (unit: MPa) of the polycarbonate resin composition measured by dynamic viscoelasticity measurement is 0.07 or more and 1.20 or less.

[0027]

[12] The film for a diaphragm according to any one of [1] to

[11] , wherein the viscosity average molecular weight of the polycarbonate resin composition is 15,000 or more and 150,000 or less.

[0028]

[13] A diaphragm for acoustic equipment, which uses the diaphragm film according to any one of [1] to

[12] .

[0029]

[14] An acoustic device having the diaphragm for an acoustic device described in

[13] .

[0030]

[15] An electronic device having the acoustic device described in

[14] . [Effects of the Invention]

[0031] The diaphragm film of the present invention has excellent low-temperature properties, heat resistance, and flexibility, and exhibits little change in elastic modulus, which is an index of flexibility, from low to high temperatures, so that it can maintain good sound quality over a wide temperature range. Therefore, by using the diaphragm film of the present invention, it is possible to provide a diaphragm for acoustic equipment that can be used in a wide temperature range from low to high and that exhibits excellent sound quality characteristics over a wide temperature range, as well as an acoustic equipment using this diaphragm for acoustic equipment and an electronic device that has this acoustic equipment. DETAILED DESCRIPTION OF THE INVENTION

[0032] The present invention will be described in detail below with reference to embodiments and examples, but the present invention should not be construed as being limited to the embodiments and examples shown below. In this specification, unless otherwise specified, the symbol "to" is used to mean that the numerical values before and after it are included as the lower limit and upper limit.

[0033] [Vibration plate film] The film for diaphragms of the present invention is a film for diaphragms obtained using a polycarbonate resin composition, the polycarbonate resin composition containing carbonate structural units (X) derived from an aliphatic dihydroxy compound (1) represented by the following formula (1) and carbonate structural units (Y) derived from a dihydroxy compound (2) satisfying the following requirement I, and the polycarbonate resin composition is a polycarbonate resin composition having a melting point peak temperature when heated at a temperature rise rate of 20°C / min using a differential scanning calorimeter and the melting point peak temperature is measured (hereinafter, this may be referred to as "the polycarbonate resin composition of the present invention"). <Requirement I> The polycarbonate resin (2) obtained by polymerizing the dihydroxy compound (2) and a carbonate source by a transesterification method has a peak melting point temperature when the peak melting point temperature is measured by heating at a temperature increase rate of 20°C / min using a differential scanning calorimeter.

[0034] [ka]

[0035] (In formula (1), X and Y are different from each other and each independently represent a single bond or a divalent linking group having 1 to 15 carbon atoms, 0 to 6 oxygen atoms, and 2 to 30 hydrogen atoms and not having a cyclic structure. n is an integer of 2 to 100.)

[0036] [Polycarbonate resin composition] First, the polycarbonate resin composition of the present invention that constitutes the diaphragm film of the present invention will be described.

[0037] <Aliphatic dihydroxy compounds (1)> The aliphatic dihydroxy compound (1) that serves as a raw material for the carbonate structural unit (X) is an aliphatic dihydroxy compound represented by the following formula (1).

[0038] [ka]

[0039] (In formula (1), X and Y are different from each other and each independently represent a single bond or a divalent linking group having 1 to 15 carbon atoms, 0 to 6 oxygen atoms, and 2 to 30 hydrogen atoms and not having a cyclic structure. n is an integer of 2 to 100.)

[0040] From the viewpoint of low-temperature impact resistance, X in the above formula (1) is preferably a divalent linking group having no cyclic structure and consisting of 1 to 15 carbon atoms, 1 to 6 oxygen atoms, and 2 to 30 hydrogen atoms, and more preferably an alkylene ether group consisting of an alkylene group having 2 to 10 carbon atoms and one oxygen atom. Y in the formula (1) is preferably a divalent linking group having no cyclic structure and consisting of 1 to 15 carbon atoms, 0 to 6 oxygen atoms, and 2 to 30 hydrogen atoms, and more preferably an alkylene group having 2 to 10 carbon atoms.

[0041] From the viewpoint of ease of polymerization, the aliphatic dihydroxy compound (1) is preferably polytrimethylene ether glycol (PO3G), which is an aliphatic dihydroxy compound represented by the following formula (2).

[0042] [ka]

[0043] (In formula (2), n is an integer of 2 to 100.)

[0044] In this case, it is preferable to use PO3G with a biomass content of 100%, which is synthesized by condensing 1,3-propanediol produced from plant-derived raw materials. Whether PO3G or other substances are produced from plant-derived resources can be determined by, for example, radiocarbon ( 14 This can be confirmed by measuring the concentration of C).

[0045] The number average molecular weight of the aliphatic dihydroxy compound (1) such as PO3G is preferably 400 or more and 10,000 or less. The lower limit of the number average molecular weight of the aliphatic dihydroxy compound (1) such as PO3G is more preferably 420 or more, and even more preferably 450 or more. The upper limit of the number average molecular weight of PO3G is more preferably 7,000 or less, and even more preferably 3,000 or less. Therefore, n in the above formulas (1) and (2) is preferably a number that satisfies this number average molecular weight.

[0046] In the polycarbonate resin composition of the present invention, the carbonate structural units (X) derived from the aliphatic dihydroxy compound (1) such as PO3G form soft segments, and the carbonate structural units (Y) derived from the dihydroxy compound (2) form hard segments, thereby exhibiting heat resistance and flexibility. When the number-average molecular weight of the aliphatic dihydroxy compound (1) such as PO3G is at least the lower limit, soft segments and hard segments are easily formed, and it tends to be easier to achieve both heat resistance and flexibility.When the number-average molecular weight of the aliphatic dihydroxy compound (1) such as PO3G is at most the upper limit, compatibility with the dihydroxy compound (2) is good, and the problem of unsuccessful polymerization can be prevented.

[0047] <Dihydroxy compound (2)> The dihydroxy compound (2) that serves as the raw material for the carbonate structural unit (Y) satisfies the following requirement I. <Requirement I> The polycarbonate resin (2) obtained by polymerizing the dihydroxy compound (2) and a carbonate source by a transesterification method has a peak melting point temperature when the peak melting point temperature is measured by heating at a temperature increase rate of 20°C / min using a differential scanning calorimeter.

[0048] In the above-mentioned requirement I, the method for producing the polycarbonate resin (2) by polymerizing the dihydroxy compound (2) and the carbonate source by the transesterification method can be specifically carried out in the same manner as the melt transesterification method in the method for producing the polycarbonate resin composition of the present invention described later. The carbonate source used in this method includes those exemplified as carbonate esters in the melt transesterification method described later.

[0049] The polycarbonate resin (2) “having a peak melting point temperature” as described above means that the polycarbonate resin (2) “has crystallinity.” If the dihydroxy compound (2) can produce a crystalline polycarbonate resin (2), the polycarbonate resin composition of the present invention having a peak melting point temperature can be produced as described below, and a polycarbonate resin composition that combines heat resistance and flexibility can be provided.

[0050] In measuring the melting peak temperature using a differential scanning calorimeter, the polycarbonate resin (2) obtained by polymerization using a transesterification method is directly subjected to the measurement of the melting peak temperature. In other words, the polycarbonate resin (2) itself must be crystalline immediately after production. Even if a polycarbonate resin obtained by dissolving a polycarbonate resin in a solvent and then drying and removing the solvent has a melting point peak temperature, this polycarbonate resin has become crystalline by being dissolved in a solvent after production, and then crystallized by drying and removing the solvent, and therefore does not satisfy requirement I of the present invention. A polycarbonate resin (2) that is itself crystalline immediately after production (a polycarbonate resin (2) that has a peak melting point temperature when the polycarbonate resin (2) obtained by polymerizing the polycarbonate resin (2) by a transesterification method is directly subjected to measurement of the peak melting point temperature) has higher crystallinity than a polycarbonate resin that has become crystalline by dissolving it in a solvent after production and then removing the solvent by drying. Therefore, in the present invention, a dihydroxy compound (2) that provides such a polycarbonate resin (2) is used.

[0051] The melting point peak temperature of the polycarbonate resin (2) is not particularly limited, but for the same reasons as those for the melting point peak temperature of the polycarbonate resin composition of the present invention described later, it is preferably 150°C or higher, more preferably 165°C or higher, and even more preferably 180°C or higher, and is preferably 330°C or lower, and more preferably 280°C or lower. When the polycarbonate resin (2) has a plurality of peak melting temperatures, it is preferable that at least the higher peak melting temperature is within the above range.

[0052] The melting peak temperature of the polycarbonate resin (2) is a melting peak temperature obtained by measuring the calorific value of the polycarbonate resin (2) by heating it at a heating rate of 20°C / min using a differential scanning calorimeter, and taking the temperature at the apex of the melting peak. Specifically, it is measured by the method described in the Examples section below.

[0053] The dihydroxy compound (2) is not particularly limited as long as it satisfies the above requirement I, and examples thereof include dihydroxy compounds represented by the following formulas (3) to (6). That is, spiroglycol represented by the following formula (3) (hereinafter, sometimes abbreviated as "SPG"), 4,4'-dihydroxydiphenyl ether represented by the following formula (4) (hereinafter, sometimes abbreviated as "DHDE"), bis(4-hydroxyphenylmethane (=bisphenol F) represented by the following formula (5) (hereinafter, sometimes abbreviated as "BPF"), and 4,4'-methylenebis(2,6-dimethylphenol) represented by the following formula (6) (hereinafter, sometimes abbreviated as "TmBPF") may be mentioned.

[0054] [ka]

[0055] The dihydroxy compounds represented by the above formulas (3) to (6) themselves have crystallinity when made into the polycarbonate resin (2). In particular, spiroglycol (SPG) represented by the above formula (3) is particularly preferred from the viewpoints of high crystallinity, high polymerizability, and compatibility between heat resistance and flexibility.

[0056] <Containing form of carbonate structural unit (X) and carbonate structural unit (Y)> There are no particular limitations on the form in which the carbonate structural unit (X) and the carbonate structural unit (Y) are contained in the polycarbonate resin composition of the present invention. Generally, the carbonate structural unit (X) and the carbonate structural unit (Y) are contained in a polycarbonate resin.

[0057] The polycarbonate resin composition of the present invention may be a polycarbonate resin mixture of a polycarbonate resin containing a carbonate structural unit (X) and a polycarbonate resin containing a carbonate structural unit (Y), or may contain a copolymer-type polycarbonate resin containing both the carbonate structural unit (X) and the carbonate structural unit (Y).

[0058] The polycarbonate resin composition of the present invention may be a mixture of a polycarbonate resin containing the carbonate structural unit (X) and / or the carbonate structural unit (Y) and a copolymer polycarbonate resin containing the carbonate structural unit (X) and the carbonate structural unit (Y).

[0059] The polycarbonate resin composition of the present invention may further contain a polycarbonate resin that does not contain either the carbonate structural unit (X) or the carbonate structural unit (Y).

[0060] When the polycarbonate resin composition of the present invention contains the carbonate structural unit (X) and the carbonate structural unit (Y) as a copolymer polycarbonate resin containing the carbonate structural unit (X) and the carbonate structural unit (Y), the polycarbonate resin composition of the present invention is referred to as a "polycarbonate resin."

[0061] When the polycarbonate resin composition of the present invention is a mixture of a polycarbonate resin containing the carbonate structural unit (X) and a polycarbonate resin containing the carbonate structural unit (Y), it is generally referred to as a "polycarbonate resin composition." The same applies to the above-mentioned other content forms.

[0062] In the present invention, the term "polycarbonate resin composition" includes cases where the composition is composed of one type of copolymer polycarbonate resin containing carbonate structural units (X) and carbonate structural units (Y). However, in the examples and comparative examples given below, a single copolymer polycarbonate resin is produced, and therefore it is referred to as a "polycarbonate resin" (the "polycarbonate resin" of the present invention).

[0063] <Content of each carbonate structural unit (X) and carbonate structural unit (Y)> The content of the carbonate structural unit (X) in 100% by mass of all carbonate structural units in the polycarbonate resin composition of the present invention (hereinafter, the contents of carbonate structural units such as the carbonate structural unit (X) and the carbonate structural unit (Y) are all expressed as mass percentages relative to 100% by mass of all carbonate structural units in the polycarbonate resin composition) is preferably 1% by mass or more and 99% by mass or less, and the content of the carbonate structural unit (Y) is preferably 1% by mass or more and 99% by mass or less. By containing from 1% by mass to 99% by mass of the carbonate structural unit (X) and from 1% by mass to 99% by mass of the carbonate structural unit (Y), the polycarbonate resin composition of the present invention can be characterized by excellent low-temperature properties (low-temperature mechanical strength), heat resistance, and flexibility, and by small change in elastic modulus, which is an index of flexibility, from low to high temperatures.

[0064] From the viewpoints of flexibility and mechanical strength, the content of the carbonate structural unit (X) in the polycarbonate resin composition of the present invention is preferably 1% by mass or more, more preferably 20% by mass or more, even more preferably 25% by mass or more, particularly preferably 27% by mass or more, and especially preferably 40% by mass or more, and the content of the carbonate structural unit (Y) is preferably 99% by mass or less, more preferably 80% by mass or less, even more preferably 75% by mass or less, particularly preferably 73% by mass or less, and especially preferably 60% by mass or less. From the viewpoint of heat resistance, the content of the carbonate structural unit (X) is preferably 99% by mass or less, more preferably 95% by mass or less, even more preferably 92% by mass or less, particularly preferably 90% by mass or less, and especially preferably 85% by mass or less, and the content of the carbonate structural unit (Y) is preferably 1% by mass or more, more preferably 5% by mass or more, even more preferably 8% by mass or more, particularly preferably 10% by mass or more, and especially preferably 15% by mass or more. The content ratio of the carbonate structural unit (X) and the content ratio of the carbonate structural unit (Y) in the polycarbonate resin composition are 1 It can be determined by measuring H-NMR.

[0065] From the viewpoint of more reliably obtaining the effects of excellent low-temperature properties (low-temperature mechanical strength), heat resistance, and flexibility, and small change in elastic modulus, which is an index of flexibility, due to the inclusion of the carbonate structural unit (X) and the carbonate structural unit (Y), the sum of the content of the carbonate structural unit (X) and the content of the carbonate structural unit (Y) in 100% by mass of all carbonate structural units in the polycarbonate resin composition of the present invention is preferably 70% by mass or more, more preferably 75% by mass or more, and even more preferably 90 to 100% by mass.

[0066] The polycarbonate resin composition of the present invention may use only one type or two or more types of aliphatic dihydroxy compounds (1) constituting the carbonate structural units (X). That is, the composition may contain carbonate structural units (X) derived from two or more types of aliphatic dihydroxy compounds (1). The composition may also contain only one type or two or more types of carbonate structural units (Y). That is, the composition may contain carbonate structural units (Y) derived from two or more types of dihydroxy compounds (2).

[0067] The content of each carbonate structural unit (X) or (Y) in the polycarbonate resin composition of the present invention can be determined as the proportion of each dihydroxy compound, i.e., the aliphatic dihydroxy compound (1) or the dihydroxy compound (2), in all dihydroxy compounds used in the production of the polycarbonate resin composition of the present invention. The same applies to the other carbonate structural units described below.

[0068] <Other carbonate structural units> The polycarbonate resin composition of the present invention may contain other carbonate structural units than the carbonate structural unit (X) and the carbonate structural unit (Y), i.e., carbonate structural units derived from aromatic or aliphatic dihydroxy compounds other than the aliphatic dihydroxy compound (1) and the dihydroxy compound (2), within the scope of the present invention.

[0069] Other carbonate structural units may also be contained as copolymer polycarbonate resins with the carbonate structural unit (X) and / or the carbonate structural unit (Y), and polycarbonate resins comprising other carbonate structural units may be mixed with polycarbonate resins containing the carbonate structural unit (X) and / or the carbonate structural unit (Y).

[0070] When the polycarbonate resin composition of the present invention contains other carbonate structural units, the content of the other carbonate structural units in 100% by mass of all carbonate structural units in the polycarbonate resin composition is preferably 30% by mass or less, particularly 25% by mass or less, and especially 10% by mass or less. When the polycarbonate resin composition contains other carbonate structural units, it may be possible to obtain improving effects such as improved mechanical strength due to the other carbonate structural units. However, if the content is too large, the effects of the present invention, such as improved low-temperature properties (low-temperature mechanical strength), heat resistance, and flexibility, which are achieved by containing the carbonate structural units (X) and (Y), may be impaired.

[0071] The polycarbonate resin composition of the present invention may contain only one type of other carbonate structural unit, or may contain two or more types.

[0072] <Other ingredients> The polycarbonate resin composition of the present invention may contain other components in addition to the polycarbonate resin containing the carbonate structural unit (X) and / or the carbonate structural unit (Y), as necessary, as long as the desired physical properties are not significantly impaired. Examples of the other components include polycarbonate resins not containing the carbonate structural unit (X) and the carbonate structural unit (Y), resins other than polycarbonate resins, various resin additives, etc.

[0073] Examples of resin additives include heat stabilizers, antioxidants, mold release agents, light stabilizers (HALS), flame retardants, antistatic agents, antifogging agents, lubricants, antiblocking agents, flow improvers, plasticizers, dispersants, antibacterial agents, dyes, pigments, etc. Furthermore, the polycarbonate resin composition of the present invention may contain a filler as needed. These resin additives may be contained alone or in any combination and ratio of two or more.

[0074] The filler contained in the polycarbonate resin composition of the present invention may be in the form of particles or fibers, but is preferably in the form of particles from the standpoint of moldability. Suitable examples of the filler include inorganic particles such as silica, mica, sericite, illite, talc, kaolinite, montmorillonite, smectite, vermiculite, titanium dioxide, potassium titanate, lithium titanate, boehmite, and alumina, and organic particles such as silicone, polytetrafluoroethylene (PTFE), and perfluoroalkoxyalkane (PFA). Among these, talc and mica are preferred from the viewpoint of improving crystallinity. Only one type of filler may be used, or two or more types may be used.

[0075] By including such a filler, the film maintains a low modulus of elasticity while suppressing tackiness, making it easier to remove from the mold after molding.

[0076] When the polycarbonate resin composition of the present invention contains a filler, the content thereof is preferably in the range of 0.1 to 5 mass% in the polycarbonate resin composition of the present invention. When the content of the filler is equal to or greater than the above-mentioned lower limit, the effect of adding the filler can be fully obtained, and when it is equal to or less than the above-mentioned upper limit, the elastic modulus of the film is maintained. From the above viewpoints, the content of the filler in the polycarbonate resin composition of the present invention is more preferably in the range of 0.5 to 4 mass%, and even more preferably in the range of 1 to 3 mass%.

[0077] Other resins that can be contained in the polycarbonate resin composition of the present invention include, for example, thermoplastic polyester resins such as polyethylene terephthalate resin, polytrimethylene terephthalate, and polybutylene terephthalate resin; styrene-based resins such as polystyrene resin, high impact polystyrene resin (HIPS), acrylonitrile-styrene copolymer (AS resin), acrylonitrile-styrene-acrylic rubber copolymer (ASA resin), and acrylonitrile-ethylene propylene rubber-styrene copolymer (AES resin); polyolefin resins such as polyethylene resin and polypropylene resin; polyamide resin; polyimide resin; polyetherimide resin; polyurethane resin; polyphenylene ether resin; polyphenylene sulfide resin; polysulfone resin; and polymethacrylate resin. The other resins may be contained either alone or in any combination and ratio of two or more.

[0078] When the polycarbonate resin composition of the present invention contains the above-mentioned other resins, from the viewpoint of more effectively obtaining the effects of the present invention provided by containing the carbonate structural unit (X) and the carbonate structural unit (Y), the content of the other resins in the polycarbonate resin composition of the present invention is preferably 10% by mass or less, particularly preferably 5% by mass or less.

[0079] <Peak Melting Point Temperature of Polycarbonate Resin Composition> The polycarbonate resin composition of the present invention has a peak melting point temperature when measured by heating at a temperature increase rate of 20°C / min using a differential scanning calorimeter, i.e., has crystallinity. The polycarbonate resin composition “having a peak melting point temperature” as described above means that the polycarbonate resin composition “has crystallinity.” Note that, in measuring the peak melting point temperature using a differential scanning calorimeter, the polycarbonate resin composition is subjected to measurement of the peak melting point temperature as is, and does not include the case where the peak melting point temperature is measured for a polycarbonate resin composition obtained by dissolving a polycarbonate resin in a solvent and then drying and removing the solvent. The polycarbonate resin composition of the present invention has a peak melting point temperature as measured by the above-mentioned differential scanning calorimeter, and thus good rubber elasticity can be obtained through pseudo-crosslinking, and a polycarbonate resin composition excellent in low-temperature properties (low-temperature mechanical strength), heat resistance, and flexibility can be provided.

[0080] The melting peak temperature of the polycarbonate resin composition of the present invention is not particularly limited, but the melting peak temperature, determined by heating the polycarbonate resin composition of the present invention at a heating rate of 20°C / min using a differential scanning calorimeter, measuring the calorific value, and taking the temperature at the apex of the melting peak, is preferably 130°C or higher, more preferably 150°C or higher, and even more preferably 180°C or higher. A melting peak temperature above the above lower limit is preferred because of excellent heat resistance. From the viewpoint of moldability, the upper limit of the melting peak temperature of the polycarbonate resin composition of the present invention is preferably 350°C or lower, more preferably 300°C or lower, and even more preferably 280°C or lower. When the polycarbonate resin composition of the present invention has a plurality of melting point peak temperatures, it is preferred that at least the higher melting point peak temperature is within the above range. The melting point peak temperature of the polycarbonate resin composition of the present invention is specifically measured by the method described in the Examples section below.

[0081] <Storage Modulus of Polycarbonate Resin Composition> The storage modulus E'(-30°C) (unit: MPa) (hereinafter sometimes simply referred to as "E'(-30°C)") of the polycarbonate resin composition of the present invention at -30°C, as determined by dynamic viscoelasticity measurement, is preferably 0.1 to 700, more preferably 1 to 500, and even more preferably 5 to 300. When E'(-30°C) is equal to or greater than the lower limit, the mechanical strength is good, whereas when E'(-30°C) is equal to or less than the upper limit, the flexibility is good.

[0082] The storage modulus E'(130°C) (unit: MPa) (hereinafter sometimes simply referred to as "E'(130°C)") of the polycarbonate resin composition of the present invention at 130°C, as determined by dynamic viscoelasticity measurement, is preferably 0.1 to 700, more preferably 1 to 500, and even more preferably 5 to 300. If E'(130°C) is equal to or greater than the lower limit, the mechanical strength is good, whereas if E'(130°C) is equal to or less than the upper limit, the flexibility is good.

[0083] Furthermore, the ratio E'(130°C) / E'(-30°C) of E'(130°C) to E'(-30°C) of the polycarbonate resin composition of the present invention is preferably 0.07 to 1.20, more preferably 0.10 to 1.10, and even more preferably 0.15 to 1.00. When the E'(130°C) / E'(-30°C) of the polycarbonate resin composition of the present invention is within the above range, the diaphragm film of the present invention exhibits small changes in elastic modulus with temperature change and has excellent heat resistance. Furthermore, because the change in elastic modulus with temperature change is small, the change in sound quality from low to high temperature ranges is small, resulting in excellent sound reproduction and less deterioration of sound quality in high-temperature environments.

[0084] The E'(-30°C) and E'(130°C) of the polycarbonate resin composition of the present invention are measured by the method described in the Examples section below.

[0085] <Molecular weight of polycarbonate resin composition> The molecular weight of the polycarbonate resin composition of the present invention is preferably 15,000 or more and 150,000 or less, in terms of viscosity average molecular weight (Mv) calculated from the solution viscosity. If the viscosity average molecular weight (Mv) is equal to or more than the above lower limit, the mechanical properties of the polycarbonate resin composition of the present invention will be good, which is preferable. If the viscosity average molecular weight (Mv) is equal to or less than the above upper limit, the flowability and moldability of the polycarbonate resin composition of the present invention will tend to be good, which is preferable. From this viewpoint, the viscosity average molecular weight (Mv) of the polycarbonate resin composition of the present invention is more preferably 20,000 or more, still more preferably 25,000 or more, and more preferably 120,000 or less, still more preferably 100,000 or less.

[0086] The viscosity average molecular weight (Mv) of the polycarbonate resin composition of the present invention can be determined by measuring the intrinsic viscosity (limiting viscosity) [η] (unit: dL / g) at 20°C using an Ubbelohde viscometer in chloroform as a solvent, and then calculating the viscosity average molecular weight (Mv) using the Schnell viscosity formula, i.e., η = 1.23 × 10 -4 Mv 0.83 The intrinsic viscosity (η) is calculated from the following formula after measuring the specific viscosity (ηsp) at each solution concentration (C) (g / dL).

[0087]

number

[0088] In the measurement of viscosity-average molecular weight, for polycarbonate resin compositions whose viscosity-average molecular weight cannot be measured because they are insoluble in a solvent, the degree of polymerization can be evaluated by the fluidity (Q value) shown below.

[0089] <Flowability (Q value) of polycarbonate resin composition> The polycarbonate resin composition of the present invention has a flowability (Q value), which is an index of moldability, of 1×10 when measured at 240°C and 160 kgf using a Koka type flow tester. -2 cm 3 / sec or more, and more preferably 5×10 -2 cm 3 / sec or more, more preferably 10 × 10 -2 cm 3 If the Q value is equal to or greater than the above lower limit, the flowability and moldability are excellent. On the other hand, if the Q value is 250×10 -2 cm 3 / sec or less, and more preferably 200 × 10 -2 cm 3 / sec or less, more preferably 150 × 10 -2 cm 3 If the Q value is equal to or less than the above upper limit, the mechanical strength is excellent.

[0090] <Glass transition temperature of polycarbonate resin composition> The glass transition temperature of the polycarbonate resin composition of the present invention is not particularly limited, but the glass transition temperature of the polycarbonate resin composition of the present invention, as determined by measuring the calorific value while heating at a heating rate of 20°C / min using a differential scanning calorimeter, is preferably 30°C or lower, more preferably 20°C or lower, and even more preferably 10°C or lower. If the glass transition temperature is below the above upper limit, the composition will have excellent low-temperature mechanical strength and rubber elasticity. There is no particular limit to the lower limit of the glass transition temperature of the polycarbonate resin composition of the present invention, but it is usually -100°C or higher. When the polycarbonate resin composition of the present invention has a plurality of glass transition temperatures, it is preferred that at least the lower glass transition temperature is within the above range.

[0091] <Biomass content of polycarbonate resin composition> The biomass degree of the polycarbonate resin composition of the present invention is defined as the mass ratio of carbonate structural units synthesized from plant-derived resources to the carbonate structural units contained in the polycarbonate resin composition of the present invention. The polycarbonate resin composition of the present invention preferably has a biomass degree of 10% by mass or more, more preferably 25% by mass or more.

[0092] [Method for producing polycarbonate resin composition] <Manufacturing method of polycarbonate resin> The polycarbonate resin constituting the polycarbonate resin composition of the present invention can be produced by a conventionally known polymerization method, and the polymerization method is not particularly limited. Examples of polymerization methods include interfacial polymerization, melt transesterification, pyridine method, ring-opening polymerization of cyclic carbonate compounds, and solid-phase transesterification of prepolymers. Among these, the melt transesterification and interfacial polymerization methods are preferred, and the melt transesterification method is more preferred. Below, particularly preferred methods among these methods will be specifically described.

[0093] (melt transesterification method) In the melt transesterification method, for example, a transesterification reaction is carried out between a carbonate ester and a raw material dihydroxy compound.

[0094] By using a raw material dihydroxy compound containing an aliphatic dihydroxy compound (1) and a dihydroxy compound (2), a copolymer polycarbonate resin containing a carbonate structural unit (X) and a carbonate structural unit (Y) can be produced. By using one of these dihydroxy compounds, a polycarbonate resin containing a carbonate structural unit (X) or a carbonate structural unit (Y) can be produced. When producing a polycarbonate resin containing the above-mentioned other carbonate structural units, one or more dihydroxy compounds other than the aliphatic dihydroxy compound (1) and the dihydroxy compound (2) may be used.

[0095] The carbonate ester may be, for example, a compound represented by the following formula (7), and examples thereof include aryl carbonates, dialkyl carbonates, biscarbonates of dihydroxy compounds, monocarbonates of dihydroxy compounds, and carbonates of dihydroxy compounds such as cyclic carbonates.

[0096] [ka]

[0097] In the above formula (7), R 11 and R 12 each independently represents an alkyl group, an aryl group, or an arylalkyl group having 1 to 30 carbon atoms, which may have a substituent. Below, R 11 and R 12 However, when the group is an alkyl group or an arylalkyl group, it is called a dialkyl carbonate, and when the group is an aryl group, it is called a diaryl carbonate. Among them, from the viewpoint of reactivity with dihydroxy compounds, R 11 and R 12 are preferably both optionally substituted aryl groups, and more preferably diaryl carbonate represented by the following formula (8).

[0098] [ka]

[0099] In the above formula (8), R 13 and R 14 are each independently a halogen atom, a nitro group, a cyano group, an alkyl group having 1 to 20 carbon atoms, an alkoxycarbonyl group having 1 to 20 carbon atoms, a cycloalkyl group having 4 to 20 carbon atoms, or an aryl group having 6 to 20 carbon atoms. p and q are each independently an integer of 0 to 5.

[0100] Specific examples of such carbonate esters include dialkyl carbonates such as dimethyl carbonate, diethyl carbonate, and di-t-butyl carbonate, diphenyl carbonate (hereinafter sometimes abbreviated as "DPC"), bis(4-methylphenyl)carbonate, bis(4-chlorophenyl)carbonate, bis(4-fluorophenyl)carbonate, bis(2-chlorophenyl)carbonate, bis(2,4-difluorophenyl)carbonate, bis(4-nitrophenyl)carbonate, bis(2-nitrophenyl)carbonate, bis(methylsalicylphenyl)carbonate, and diaryl carbonates which may have a substituent such as ditolyl carbonate. Of these, diphenyl carbonate is preferred. These carbonate esters can be used alone or in combination of two or more.

[0101] The carbonate ester may be substituted with a dicarboxylic acid or dicarboxylic acid ester, preferably in an amount of 50 mol % or less, more preferably 30 mol % or less. Typical dicarboxylic acids or dicarboxylic acid esters include terephthalic acid, isophthalic acid, diphenyl terephthalate, and diphenyl isophthalate. When substituted with such a dicarboxylic acid or dicarboxylic acid ester, a polyester carbonate is obtained.

[0102] The ratio of the starting dihydroxy compound to the carbonate ester may be any ratio as long as the desired polycarbonate resin is obtained. When polymerizing the carbonate ester with the dihydroxy compound, it is preferable to use a slightly smaller amount or a slightly larger amount than the starting dihydroxy compound. That is, the amount of the carbonate ester is preferably 0.95 to 1.30 times (molar ratio), more preferably 0.98 to 1.20 times (molar ratio), relative to the amount of the dihydroxy compound. If this molar ratio is too small, the resulting polycarbonate resin will have many terminal OH groups, which tends to deteriorate the thermal stability of the resin.If this molar ratio is too large, the transesterification reaction rate will decrease, making it difficult to produce a polycarbonate resin with the desired molecular weight, or the amount of carbonate ester remaining in the resin will increase, which may cause an odor during molding or when the molded product is made.

[0103] When producing a polycarbonate resin by the melt transesterification method, a transesterification catalyst is usually used. The transesterification catalyst is not particularly limited, and conventionally known catalysts can be used. For example, it is preferable to use an alkali metal compound and / or an alkaline earth metal compound. In addition, a basic compound such as a basic boron compound, a basic phosphorus compound, a basic ammonium compound, or an amine compound may be used in combination as an auxiliary. The transesterification catalyst may be used alone or in any combination of two or more in any ratio.

[0104] In the melt transesterification method, the reaction temperature is not particularly limited, but is usually 100 to 300°C. The pressure during the reaction is not particularly limited, but is usually reduced to 2 mmHg or less. Specifically, the melt polycondensation reaction may be carried out under the above conditions while removing by-products.

[0105] In the presence of an alkali catalyst, the polycarbonate resin composition of the present invention is significantly affected by thermal history and oxidation, leading to deterioration of color. Therefore, the reaction temperature is preferably set to 300°C or lower. In addition, to prevent oxygen leakage from the equipment due to excessive pressure reduction, it is preferable to select reduced pressure conditions with a lower limit of approximately 0.05 mmHg.

[0106] The reaction can be carried out in either a batch or continuous manner. When the reaction is carried out in a batch manner, the order in which the reaction substrates (reaction raw materials), catalyst, additives, etc. are mixed can be any order as long as the desired polycarbonate resin can be obtained, and an appropriate order can be set as desired.

[0107] In the melt transesterification method, a catalyst deactivator may be used as needed. As the catalyst deactivator, any compound that neutralizes the transesterification catalyst can be used. Examples of such a catalyst deactivator include sulfur-containing acidic compounds and their derivatives, phosphorus-containing acidic compounds and their derivatives, etc. The catalyst deactivator may be used alone or in any combination of two or more in any ratio.

[0108] The amount of catalyst deactivator used is not particularly limited, but is usually 0.5 equivalents or more, preferably 1 equivalent or more, more preferably 3 equivalents or more, and usually 50 equivalents or less, preferably 10 equivalents or less, more preferably 8 equivalents or less, relative to the transesterification catalyst. The amount of the catalyst deactivator used is usually 1 ppm or more and 1000 ppm or less, preferably 500 ppm or less, based on the polycarbonate resin.

[0109] <Method for producing polycarbonate resin composition> When the polycarbonate resin composition of the present invention is a mixture of a polycarbonate resin containing a carbonate structural unit (X) and a polycarbonate resin containing a carbonate structural unit (Y), or a mixture of a polycarbonate resin containing a carbonate structural unit (X) and / or a carbonate structural unit (Y) and a copolymer polycarbonate resin containing the carbonate structural unit (X) and the carbonate structural unit (Y), or a mixture containing a polycarbonate resin containing neither the carbonate structural unit (X) nor the carbonate structural unit (Y), the polycarbonate resin composition of the present invention may be a polycarbonate resin composition containing two or more polycarbonate resins. For example, there are no particular limitations on the method for producing the polycarbonate resin composition of the present invention by mixing two or more polycarbonate resins, for example, polycarbonate resin (a) and polycarbonate resin (b). Examples of the method include the following methods 1) to 4). 1) A method of melt-kneading a polycarbonate resin (a) and a polycarbonate resin (b); 2) A method of melt-kneading a molten polycarbonate resin (a) and a molten polycarbonate resin (b); 3) A method in which the polycarbonate resin (a) and the polycarbonate resin (b) are mixed in a solution state; 4) A method of dry blending polycarbonate resin (a) and polycarbonate resin (b); Each method will be explained below.

[0110] 1) A method of melt-kneading a polycarbonate resin (a) and a polycarbonate resin (b); Pellets or powder particles of polycarbonate resin (a) and pellets or powder particles of polycarbonate resin (b) are melt-kneaded using a mixing device such as a kneader, twin-screw extruder, single-screw extruder, etc. Pellets or powder particles of polycarbonate resin (a) and pellets or powder particles of polycarbonate resin (b) may be mixed in advance in a solid state and then kneaded, or one of them may be melted first in the mixing device, and the other polycarbonate resin may be added thereto and kneaded.

[0111] There are no particular restrictions on the temperature during kneading, but it is preferably 200°C or higher, more preferably 220°C or higher, and even more preferably 230°C or higher. Also, it is preferably 320°C or lower, and particularly preferably 300°C or lower. If the kneading temperature is too low, the polycarbonate resin (a) and the polycarbonate resin (b) may not be mixed completely, which may result in variations in hardness and impact resistance when a molded product is produced, and this is undesirable. If the kneading temperature is too high, the color tone of the polycarbonate resin composition may deteriorate, which is also undesirable.

[0112] 2) A method of melt-kneading a molten polycarbonate resin (a) and a molten polycarbonate resin (b); The molten polycarbonate resin (a) and the molten polycarbonate resin (b) are mixed using a mixing device such as a stirring tank, a static mixer, a kneader, a twin-screw extruder, a single-screw extruder, etc. In this case, if the polycarbonate resin is obtained by, for example, a melt polymerization method, it may be introduced into the mixing device in a molten state without being cooled and solidified.

[0113] 3) A method in which the polycarbonate resin (a) and the polycarbonate resin (b) are mixed in a solution state; In this method, polycarbonate resin (a) and polycarbonate resin (b) are dissolved in an appropriate solvent to form a solution, mixed in the solution state, and then isolated as a polycarbonate resin composition.

[0114] Suitable solvents include, for example, aliphatic hydrocarbons such as hexane and n-heptane; chlorinated aliphatic hydrocarbons such as dichloromethane, chloroform, carbon tetrachloride, dichloroethane, trichloroethane, tetrachloroethane, dichloropropane, and 1,2-dichloroethylene; aromatic hydrocarbons such as benzene, toluene, and xylene; and substituted aromatic hydrocarbons such as nitrobenzene and acetophenone. Among these, chlorinated hydrocarbons such as dichloromethane and chlorobenzene are preferred. These solvents can be used alone or in combination with other solvents.

[0115] Examples of the mixing device include a stirring tank, a static mixer, etc. The mixing temperature is not particularly limited as long as the polycarbonate resin (a) and the polycarbonate resin (b) are dissolved, and the mixing is usually carried out at a temperature equal to or lower than the boiling point of the solvent used.

[0116] 4) A method of dry blending polycarbonate resin (a) and polycarbonate resin (b); This method involves dry blending pellets or granules of polycarbonate resin (a) with pellets or granules of polycarbonate resin (b) using a tumbler, super mixer, Henschel mixer, Nauta mixer, or the like.

[0117] Among the above methods 1) to 4), methods 1) and 2) in which polycarbonate resin (a) and polycarbonate resin (b) are melt-kneaded, and method 4) in which polycarbonate resin (a) and polycarbonate resin (b) are dry-blended are preferred.

[0118] In producing the polycarbonate resin composition, in any of the above methods, fillers, pigments, dyes, mold release agents, heat stabilizers, etc. may be added as appropriate within the range that does not impair the object of the present invention.

[0119] [Method of manufacturing diaphragm film] The diaphragm film of the present invention can be produced by a general molding method, such as extrusion molding, injection molding, blow molding, vacuum molding, pressure molding, press molding, etc., using the polycarbonate resin composition of the present invention described above. The apparatus and processing conditions for each molding method are not particularly limited, but extrusion molding, particularly the T-die method, is preferred from the viewpoint of productivity and thickness control. The polycarbonate resin composition extruded through a T-die can be taken up, for example, by a cast roll. When the film is taken up, in order to prevent the wound film from fusing together or from being wound onto a metal roll, the film may be formed by an extrusion lamination method using a film such as polyethylene terephthalate or polypropylene.

[0120] The molding temperature when molding the polycarbonate resin composition of the present invention is preferably 200° C. or higher, more preferably 220° C. or higher, and even more preferably 230° C. or higher, and is preferably 320° C. or lower, and more preferably 300° C. or lower. If the molding temperature is too low, the melt viscosity will be high, the fluidity will be reduced, and moldability may be reduced. If the molding temperature is too high, the polycarbonate resin composition will be colored, and the color tone of the resulting diaphragm film may also be deteriorated, which is undesirable. In addition, polycarbonate resin compositions containing structural units derived from aliphatic dihydroxy compounds, such as carbonate structural units (X), may decompose at high temperatures.

[0121] When injection molding or extrusion molding is carried out, fillers, pigments, dyes, mold release agents, heat stabilizers, etc. may be added to the polycarbonate resin composition of the present invention as appropriate within the range that does not impair the object of the present invention.

[0122] The method for producing the diaphragm film of the present invention is not particularly limited, but for example, the film can be obtained by molding the constituent material of the film (i.e., the polycarbonate resin composition of the present invention) 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.

[0123] For example, the diaphragm film of the present invention can be produced by melt-kneading the constituent materials of the polycarbonate resin composition of the present invention to obtain a polycarbonate resin composition, extruding the polycarbonate 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 the melt-kneading are as described above. The molding can be carried out by extrusion molding using a mold such as a T-die, and it is preferable to cool the mixture using a cast roll.

[0124] 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, the film has excellent adhesion to the film, is less likely to wrinkle due to rapid cooling, and has a good appearance. 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 mark when it is released, making it easier to obtain a film with a good appearance. 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.

[0125] In the case of an unstretched film, for example, the components constituting the polycarbonate resin composition may be melt-kneaded at the above-mentioned melting temperature to obtain a polycarbonate resin composition, and the polycarbonate resin composition may be formed into a film by press molding or lamination molding.

[0126] [Thickness of diaphragm film] The thickness of the diaphragm film of the present invention is preferably 1 μm or more and 500 μm or less, more preferably 2 μm or more and 300 μm or less, even more preferably 3 μm or more and 200 μm or less, and particularly preferably 4 μm or more and 150 μm or less. If the thickness is within this range, the balance between handling properties and sound quality is excellent, and further, it tends to contribute to miniaturization of the diaphragm and space saving.

[0127] [Application] The diaphragm film of the present invention has excellent low-temperature properties, heat resistance, and flexibility, exhibits little change in elastic modulus (an index of flexibility) from low to high temperatures, and can maintain good sound quality over a wide temperature range, making it useful as a diaphragm film for acoustic devices such as speakers in electronic devices. Specifically, it can be used for various electroacoustic transducers (acoustic diaphragms) such as speakers, receivers, microphones, and earphones, and among these, speaker diaphragms are more preferred, and it can be particularly suitably used as a diaphragm for microspeakers in mobile phones, smartphones, portable music devices, portable game consoles, tablet PCs, and the like. The diaphragm film of the present invention is appropriately subjected to secondary processing and molded into various acoustic devices, preferably into diaphragms for electroacoustic transducers, and particularly preferably into diaphragms for speakers. The diaphragm film of the present invention may be, for example, at least a portion of the film processed into a dome shape, a cone shape, or the like. Furthermore, a tangential edge may be provided on the surface of the film. When processed into a dome shape or a cone shape or when a tangential edge is provided, the film is preferably used as a diaphragm for an acoustic device, more preferably as a diaphragm for a speaker. 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 then mold the film by press molding, vacuum molding, or the like.

[0128] [Diaphragm for audio equipment] To explain in more detail the diaphragm for acoustic equipment using the diaphragm film of the present invention, the shape of the diaphragm is not particularly limited and can be any shape, such as a circular shape, an elliptical shape, or an oval shape. Furthermore, diaphragms for acoustic equipment generally have a body that vibrates in response to an electrical signal or the like, and an edge surrounding 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 commonly used for diaphragms.

[0129] The diaphragm film of the present invention may form at least a part of the diaphragm for an acoustic device, and for example, the body or edge of the diaphragm may be formed from the diaphragm film of the present invention, and the edge or body of the diaphragm may be formed from a separate member. Of course, both the body and the edge may be integrally formed from the diaphragm film of the present invention, or the entire diaphragm for an acoustic device may be formed from the diaphragm film of the present invention.

[0130] [Electronic equipment] The electronic device of the present invention includes an acoustic device having a diaphragm for acoustic devices using the diaphragm film of the present invention. Here, the acoustic device refers to a device for recording, reproducing, or converting sound, and specifically refers to devices such as a speaker, a receiver, a microphone, and an earphone. Preferred examples of the electronic device of the present invention that includes such an acoustic device include mobile phones, smartphones, portable music devices, portable game consoles, and tablet PCs. [Example]

[0131] The present invention will be described in more detail below with reference to examples, although the present invention is not limited to the following examples. The physical properties of the polycarbonate resins obtained in the following Examples and Comparative Examples were evaluated by the following methods.

[0132] (1) Viscosity average molecular weight (Mv) The polycarbonate resin was dissolved in chloroform (concentration 6.0 g / L), and the intrinsic viscosity (limiting viscosity) [η] (unit: dL / g) at 20°C was determined using an Ubbelohde viscosity tube (manufactured by Moritomo Rika Kogyo Co., Ltd.), and the viscosity average molecular weight (Mv) was calculated using Schnell's viscosity formula (the following formula). η = 1.23 × 10 -4 Mv 0.83 Although methylene chloride is usually used as a solvent to measure the viscosity average molecular weight of a polycarbonate resin, the polycarbonate resin of the present invention has poor solubility in methylene chloride, so the measurement was carried out using chloroform instead of methylene chloride.

[0133] (2) Q value The flowability of the resin was evaluated by measuring its flow value (Q value). Measurements were carried out using a Shimadzu CFT-500EX flow tester with a die having a hole diameter of 1.0 mm and a length of 10 mm, at a test temperature of 240°C and a test force of 160 kg / cm. 2 , the amount of molten resin discharged under the condition of a preheating time of 180 seconds (unit: × 10 -2 cm 3The Q value is an index of melt viscosity, and equivalent values indicate equivalent moldability.

[0134] (3) Glass transition temperature (Tg) and melting point peak temperature (Tm) Measurements were performed using a differential scanning calorimeter (DSC6220, manufactured by SII). The resulting polycarbonate resin was used as the measurement sample without drying. An aluminum sample pan containing approximately 10 mg of the measurement sample was heated from 30°C to 300°C at a heating rate of 20°C / min with a nitrogen gas flow rate of 50 mL / min, and then cooled to -120°C at a heating rate of 40°C / min. The pan was then heated again to 300°C at a heating rate of 20°C / min. The differential scanning calorimetry curve obtained in the second temperature rise was analyzed as the measurement curve. The glass transition temperature (Tg) and melting peak temperature (Tm) were analyzed in accordance with JIS K7121-1987. The extrapolated glass transition onset temperature was determined as the temperature at the intersection of a straight line extending the low-temperature baseline toward the high-temperature side and a tangent drawn at the point where the gradient of the step-like change in the glass transition curve is maximum. This extrapolated glass transition temperature was designated the glass transition temperature (Tg). The peak melting point temperature (Tm) was designated as the peak of the melting point temperature.

[0135] (4) Dynamic viscoelasticity measurement Measurements were performed using a viscoelasticity spectrometer (DVA-200, manufactured by IT Measurement & Control Co., Ltd.). The resulting polycarbonate resin was sandwiched between two metal plates and press-molded at a temperature of 230°C, a pressure of 3 MPa, and a molding time of 10 seconds to form a 0.3 mm-thick polycarbonate resin film. A 4 mm x 8 cm test piece was cut from the resulting film and measured using a viscoelasticity spectrometer in accordance with JIS K7244-4:1999. Measurement mode: tensile; frequency: 10 GHz; strain: 0.1%; temperature range: -50 to 300°C; heating rate: 3°C / min. Storage moduli at -30°C and 130°C (E'(-30°C) and E'(130°C), respectively) were measured, and the ratio of the elastic moduli at 130°C to -30°C was calculated.

[0136] [raw materials] The compounds used in the following Examples and Comparative Examples are abbreviated as follows: The compounds used were manufactured by the following manufacturers. Of the following compounds, plant-derived raw materials were used for PO3G.

[0137] <Hydroxy compounds> PO3G1000: Polytrimethylene ether glycol, number average molecular weight 1076 (manufactured by ALLESSA, trade name: VELVETOL) PO3G2700-1: Polytrimethylene ether glycol, number average molecular weight 2723 (manufactured by ALLESSA, trade name: VELVETOL) PO3G2700-2: Polytrimethylene ether glycol, number average molecular weight 2743 (manufactured by ALLESSA, trade name: VELVETOL) SPG: Spiroglycol (Mitsubishi Gas Chemical Company, Inc.) DHDE: 4,4'-dihydroxydiphenyl ether (Tokyo Chemical Industry Co., Ltd.) BPF: Bis(4-hydroxyphenyl)methane (=bisphenol F) (Tokyo Chemical Industry Co., Ltd.) TmBPF: 4,4-methylenebis(2,6-dimethylphenol) (Tokyo Chemical Industry Co., Ltd.) BPA: 2,2-bis(4-hydroxyphenyl)propane (=bisphenol A) (Mitsubishi Chemical Corporation) THPE: 1,1,1-tris(4-hydroxyphenyl)ethane (Tokyo Chemical Industry Co., Ltd.)

[0138] <Carbonate ester> DPC: Diphenyl carbonate (Mitsubishi Chemical Corporation)

[0139] <Polymerization catalyst> Calcium acetate monohydrate (Fujifilm Wako Pure Chemical Industries, Ltd.) Cesium carbonate (Kishida Chemical Co., Ltd.)

[0140] [Measurement of the melting point peak temperature of polycarbonate resin (2)] Using only the compounds shown in Table 1 as dihydroxy compounds, polycarbonate resins (corresponding to polycarbonate resin (2)) containing 100% by mass of carbonate structural units (Y) were produced by the polymerization method described below, and their peak melting points were measured. The measurement method was the same as above, except that the temperature was lowered to 50°C instead of -120°C at a temperature lowering rate of 10 to 40°C / min. The results are shown in Table 1. If the polycarbonate resin (2) has a peak melting point when measured at a temperature lowering rate of 10 to 40°C / min (generally, the slower the temperature lowering rate, the easier it is to detect the peak melting point), it is judged to have such a peak melting point.

[0141] [Table 1]

[0142] [SPG polymerization method] A raw material mixture was prepared by adding 116.71 g (approximately 0.383 mol) of SPG, 83.37 g (approximately 0.389 mol) of DPC, and a 3.0 mass% aqueous solution of calcium acetate monohydrate as a catalyst to a 570 mL glass reactor equipped with a reactor stirrer, a reactor heating device, and a reactor pressure adjusting device so that the calcium acetate monohydrate was present at 100 μmol per 1 mol of the total dihydroxy compounds.

[0143] Next, the pressure inside the glass reactor was reduced to 1.3 to 4.0 kPa (10 to 30 Torr), and then the pressure was returned to atmospheric pressure with nitrogen. This operation was repeated five times to purge the inside of the reactor with nitrogen. After nitrogen purge, the external temperature of the reactor was increased to 220°C, and the internal temperature of the reactor was gradually increased to dissolve the mixture. The stirrer was then rotated at 100 rpm. Then, the pressure inside the reactor was reduced from 101.3 kPa (760 Torr) to 13.3 kPa (100 Torr) absolute over 40 minutes, while distilling off phenol, which was a by-product of the oligomerization reaction of the dihydroxy compound and DPC inside the reactor.

[0144] Next, the pressure inside the reactor was maintained at 13.3 kPa, and the transesterification reaction was carried out for 45 minutes while further distilling off phenol. The temperature outside the reactor was then raised to 285°C, and the pressure inside the reactor was reduced from 13.3 kPa (100 Torr) to 399 Pa (3 Torr) absolute over 40 minutes, and the distilled phenol was removed from the system. The absolute pressure inside the reactor was then further reduced to 60 Pa (approximately 0.4 Torr), and the polycondensation reaction was carried out. The polycondensation reaction was terminated when the reactor's agitator reached a predetermined stirring power.

[0145] Next, the pressure inside the reactor was restored to 101.3 kPa absolute pressure with nitrogen, and then increased to 0.2 MPa gauge pressure. The polycarbonate resin was extracted in the form of strands from the bottom of the reactor, and the strand-like polycarbonate resin was obtained and then pelletized using a rotary cutter.

[0146] [DHDE polymerization method] A raw material mixture was prepared by adding 116.71 g (approximately 0.577 mol) of DHDE, 123.64 g (approximately 0.577 mol) of DPC, and a 0.4 mass% aqueous solution of cesium carbonate as a catalyst to a glass reactor having an internal volume of 570 mL and equipped with a reactor stirrer, a reactor heating device, and a reactor pressure adjusting device, so that the amount of cesium carbonate was 5 μmol per 1 mol of the total dihydroxy compounds.

[0147] Next, the pressure inside the glass reactor was reduced to 1.3 to 4.0 kPa (10 to 30 Torr), and then the pressure was returned to atmospheric pressure with nitrogen. This operation was repeated five times to purge the inside of the reactor with nitrogen. After nitrogen purge, the external temperature of the reactor was increased to 220°C, and the internal temperature of the reactor was gradually increased to dissolve the mixture. The stirrer was then rotated at 100 rpm. Then, the pressure inside the reactor was reduced from 101.3 kPa (760 Torr) to 13.3 kPa (100 Torr) absolute over 40 minutes, while distilling off phenol, which was a by-product of the oligomerization reaction of the dihydroxy compound and DPC inside the reactor.

[0148] Next, the pressure inside the reactor was maintained at 13.3 kPa, and the transesterification reaction was carried out for 80 minutes while further distilling off phenol. The temperature outside the reactor was then raised to 250°C, and the pressure inside the reactor was reduced from 13.3 kPa (100 Torr) to 399 Pa (3 Torr) absolute over 40 minutes, and the distilled phenol was removed from the system. The temperature outside the reactor was then raised to 280°C, and the absolute pressure inside the reactor was reduced to 60 Pa (approximately 0.4 Torr), and the polycondensation reaction was carried out. The polycondensation reaction was terminated when the reactor's agitator reached a predetermined stirring power.

[0149] Next, the pressure inside the reactor was restored to 101.3 kPa absolute pressure with nitrogen, and then increased to 0.2 MPa gauge pressure. The polycarbonate resin was extracted in the form of strands from the bottom of the reactor, and the strand-like polycarbonate resin was obtained and then pelletized using a rotary cutter.

[0150] [TmBPF polymerization method] A raw material mixture was prepared by adding 116.71 g (approximately 0.455 mol) of TmBPF, 99.97 g (approximately 0.467 mol) of DPC, and a 0.4 mass% aqueous solution of cesium carbonate as a catalyst, so that the cesium carbonate concentration was 20 μmol per 1 mol of total dihydroxy compounds. The DHDE polymerization method was used, except that the external temperature of the reactor was raised to 290 °C instead of 250 °C when reducing the pressure from 13.3 kPa (100 Torr), and the reaction was continued at 290 °C until the end of the reaction. Crystallization occurred during the polymerization, making it difficult to extract the polycarbonate resin in strand form. Therefore, the polycarbonate resin was extracted from the reactor together with the stirring blade, and the polycarbonate resin was obtained.

[0151] [BPF polymerization method] A raw material mixture was prepared by adding 10.00 g (approximately 0.0499 mol) of BPF, 10.97 g (approximately 0.0512 mol) of DPC, and a 0.4 mass% aqueous solution of cesium carbonate as a catalyst so that the cesium carbonate concentration was 10 μmol per 1 mol of all dihydroxy compounds. The polymerization was carried out using the DHDE polymerization method, except that the external temperature of the reactor was raised to 285°C instead of 250°C when reducing the pressure from 13.3 kPa (100 Torr), and the temperature was maintained at 285°C until the end of the reaction. A polycarbonate resin was obtained.

[0152] [BPA polymerization method] A raw material mixture was prepared by adding 116.71 g (approximately 0.511 mol) of BPA, 117.18 g (approximately 0.547 mol) of DPC, and a 0.04 mass% aqueous solution of cesium carbonate as a catalyst so that the cesium carbonate concentration was 0.5 μmol per 1 mol of all dihydroxy compounds. The polymerization was carried out by the DHDE polymerization method, except that the external temperature of the reactor was raised to 290°C instead of 250°C when reducing the pressure from 13.3 kPa (100 Torr), and the temperature was maintained at 290°C until the end of the reaction. A polycarbonate resin was obtained.

[0153] [Example 1] A raw material mixture was prepared by adding 70.03 g (approximately 0.0255 mol) of PO3G2700-1, 46.68 g (approximately 0.153 mol), 40.05 g (approximately 0.187 mol) of SPG, 40.05 g (approximately 0.187 mol) of DPC, and a 3.0 mass% aqueous solution of calcium acetate monohydrate as a catalyst to a glass reactor having an internal volume of 570 mL and equipped with a reactor stirrer, a reactor heating device, and a reactor pressure adjusting device. The amount of calcium acetate monohydrate was 100 μmol per 1 mol of the total dihydroxy compounds.

[0154] Next, the pressure inside the glass reactor was reduced to 1.3 to 4.0 kPa (10 to 30 Torr), and then the pressure was returned to atmospheric pressure with nitrogen. This operation was repeated five times to purge the inside of the reactor with nitrogen. After nitrogen purge, the external temperature of the reactor was increased to 220°C, and the internal temperature of the reactor was gradually increased to dissolve the mixture. The agitator was then rotated at 100 rpm. After stirring for 60 minutes, the temperature was increased to 240°C, and the pressure inside the reactor was reduced from 101.3 kPa (760 Torr) to 13.3 kPa (100 Torr) absolute over 40 minutes while distilling off phenol, which was a by-product of the oligomerization reaction of the dihydroxy compound and DPC inside the reactor.

[0155] Next, the pressure inside the reactor was maintained at 13.3 kPa, and the transesterification reaction was carried out for 80 minutes while further distilling off phenol. The temperature outside the reactor was then raised to 250°C, and the pressure inside the reactor was reduced from 13.3 kPa (100 Torr) to 399 Pa (3 Torr) absolute over 40 minutes, and the distilled phenol was removed from the system. The absolute pressure inside the reactor was then reduced to 40 Pa (approximately 0.3 Torr), and the polycondensation reaction was carried out. The polycondensation reaction was terminated when the reactor's agitator reached a predetermined stirring power.

[0156] Next, the pressure inside the reactor was restored to 101.3 kPa absolute pressure with nitrogen, and then increased to 0.2 MPa gauge pressure. The polycarbonate resin was extracted in the form of strands from the bottom of the reactor, and the strand-like polycarbonate resin was obtained and then pelletized using a rotary cutter. This polycarbonate resin contains 58.2 mass % of carbonate structural units (X) and 41.8 mass % of carbonate structural units (Y), and has a biomass content of 57.7 mass %.

[0157] The viscosity average molecular weight (Mv), glass transition temperature (Tg), melting peak temperature (Tm), and dynamic viscoelasticity of the polycarbonate resin thus obtained were measured. The results are shown in Table 2.

[0158] [Example 2] A raw material mixture was prepared from 81.70 g (approximately 0.0298 mol) of PO3G2700-1, 35.01 g (approximately 0.115 mol), 32.42 g (approximately 0.151 mol) of DPC, and a 3.0 mass% aqueous solution of calcium acetate monohydrate as a catalyst, with the addition of calcium acetate monohydrate at 100 μmol per 1 mol of total dihydroxy compounds. A polycarbonate resin was produced in the same manner as in Example 1, except that the external temperature of the reactor was not increased to 250°C when the pressure was reduced from 13.3 kPa (100 Torr) but was maintained at 240°C during the reaction. The obtained polycarbonate resin contained 68.5% by mass of carbonate structural units (X) and 31.5% by mass of carbonate structural units (Y), and had a biomass content of 67.8% by mass.

[0159] The viscosity average molecular weight (Mv), glass transition temperature (Tg), melting peak temperature (Tm), and dynamic viscoelasticity of the polycarbonate resin thus obtained were measured. The results are shown in Table 2.

[0160] [Example 3] A raw material mixture was prepared by adding 58.36 g (approximately 0.0213 mol) of PO3G2700-2, 58.36 g (approximately 0.289 mol) of DHDE, 68.04 g (approximately 0.318 mol) of DPC, and a 0.4 mass% aqueous solution of cesium carbonate as a catalyst to a 570 mL glass reactor equipped with a reactor stirrer, a reactor heating device, and a reactor pressure adjusting device, so that the concentration of cesium carbonate was 5 μmol per 1 mol of all dihydroxy compounds.

[0161] Next, the pressure inside the glass reactor was reduced to 1.3 to 4.0 kPa (10 to 30 Torr), and then the pressure was returned to atmospheric pressure with nitrogen. This operation was repeated five times to purge the inside of the reactor with nitrogen. After nitrogen purge, the external temperature of the reactor was increased to 220°C, and the internal temperature of the reactor was gradually increased to dissolve the mixture. The stirrer was then rotated at 100 rpm. Then, the pressure inside the reactor was reduced from 101.3 kPa (760 Torr) to 13.3 kPa (100 Torr) absolute over 40 minutes, while distilling off phenol, which was a by-product of the oligomerization reaction of the dihydroxy compound and DPC inside the reactor.

[0162] Next, the pressure inside the reactor was maintained at 13.3 kPa, and the transesterification reaction was carried out for 80 minutes while further distilling off phenol. The temperature outside the reactor was then raised to 240°C, and the pressure inside the reactor was reduced from 13.3 kPa (100 Torr) to 399 Pa (3 Torr) absolute over 40 minutes, and the distilled phenol was removed from the system. The temperature outside the reactor was then raised to 260°C, and the absolute pressure inside the reactor was reduced to 60 Pa (approximately 0.4 Torr), and the polycondensation reaction was carried out. The polycondensation reaction was terminated when the reactor's agitator reached a predetermined stirring power.

[0163] Next, the pressure inside the reactor was restored to 101.3 kPa absolute pressure with nitrogen, and then increased to 0.2 MPa gauge pressure. The polycarbonate resin was extracted in the form of strands from the bottom of the reactor, and the strand-shaped polycarbonate resin was obtained and then cut into pellets with scissors. The obtained polycarbonate resin contained 47.2 mass % of carbonate structural units (X) and 52.8 mass % of carbonate structural units (Y), and had a biomass content of 46.7 mass %.

[0164] The viscosity average molecular weight (Mv), glass transition temperature (Tg), melting peak temperature (Tm), and dynamic viscoelasticity of the polycarbonate resin thus obtained were measured. The results are shown in Table 2.

[0165] [Example 4] After polymerizing polycarbonate resin by the method described in Example 3, Micron White 5000S (talc manufactured by Hayashi Kasei Co., Ltd.) was added to the mixture so as to obtain the content shown in Table 2, followed by stirring. The polycarbonate resin was extracted in the form of strands from the bottom of the reactor, and the strand-shaped polycarbonate resin was obtained and cut into pellets with scissors. The obtained polycarbonate resin contained 46.7 mass % of carbonate structural units (X) and 52.3 mass % of carbonate structural units (Y), and had a biomass content of 46.2 mass %.

[0166] The viscosity average molecular weight (Mv), glass transition temperature (Tg), melting peak temperature (Tm), and dynamic viscoelasticity of the polycarbonate resin thus obtained were measured. The results are shown in Table 2.

[0167] [Example 5] A raw material mixture was prepared from 70.03 g (approximately 0.0255 mol) of PO3G2700-2, 46.68 g (approximately 0.231 mol), 56.57 g (approximately 0.264 mol), and a 0.4 mass% aqueous solution of cesium carbonate as a catalyst, with the addition of 5 μmol of cesium carbonate per 1 mol of the total dihydroxy compounds. A polycarbonate resin was produced by the method described in Example 1. The obtained polycarbonate resin contained 57.3 mass % of carbonate structural units (X) and 42.7 mass % of carbonate structural units (Y), and had a biomass content of 56.7 mass %.

[0168] The viscosity average molecular weight (Mv), glass transition temperature (Tg), melting peak temperature (Tm), and dynamic viscoelasticity of the polycarbonate resin thus obtained were measured. The results are shown in Table 2.

[0169] [Example 6] A raw material mixture was prepared from 80.47 g (approximately 0.0296 mol) of PO3G2700-1, 34.49 g (approximately 0.135 mol), 1.75 g (approximately 0.00439 mol), 36.93 g (approximately 0.172 mol), and a 3.0 mass% aqueous solution of calcium acetate monohydrate as a catalyst, with the calcium acetate monohydrate added so that the amount was 500 μmol per mole of total dihydroxy compounds. A polycarbonate resin was produced in the same manner as in Example 1, except that the external temperature of the reactor was increased to 260°C instead of 250°C when the pressure was reduced from 13.3 kPa (100 Torr). The obtained polycarbonate resin contained 67.0 mass % of carbonate structural units (X), 31.4 mass % of carbonate structural units (Y), and 1.6 mass % of other carbonate structural units, and had a biomass content of 66.3 mass %.

[0170] The viscosity average molecular weight (Mv), glass transition temperature (Tg), melting peak temperature (Tm), and dynamic viscoelasticity of the polycarbonate resin thus obtained were measured. The results are shown in Table 2.

[0171] [Example 7] A raw material mixture was prepared from 10.00 g (approximately 0.00365 mol) of PO3G2700-2, 10.00 g (approximately 0.0499 mol), 12.05 g (approximately 0.0563 mol), and a 0.4 mass% aqueous solution of cesium carbonate as a catalyst, with the addition of 5 μmol of cesium carbonate per 1 mol of the total dihydroxy compounds. A polycarbonate resin was produced by the method described in Example 3. The obtained polycarbonate resin contained 47.2 mass % of carbonate structural units (X) and 52.8 mass % of carbonate structural units (Y), and had a biomass content of 46.7 mass %.

[0172] The viscosity average molecular weight (Mv), glass transition temperature (Tg), melting peak temperature (Tm), and dynamic viscoelasticity of the polycarbonate resin thus obtained were measured. The results are shown in Table 2.

[0173] [Comparative Example 1] A raw material mixture was prepared from 58.36 g (approximately 0.0213 mol) of PO3G2700-2, 58.36 g (approximately 0.256 mol), 62.29 g (approximately 0.291 mol), and a 0.4 mass% aqueous solution of cesium carbonate as a catalyst, with the addition of 5 μmol of cesium carbonate per 1 mol of the total dihydroxy compounds. A polycarbonate resin was produced by the method described in Example 6. The obtained polycarbonate resin contained 47.5% by mass of carbonate structural units (X) and 52.5% by mass of other carbonate structural units, and had a biomass content of 46.9% by mass.

[0174] The viscosity average molecular weight (Mv), glass transition temperature (Tg), melting peak temperature (Tm), and dynamic viscoelasticity of the polycarbonate resin thus obtained were measured. The results are shown in Table 2.

[0175] Comparative Example 2 The glass transition temperature (Tg), melting peak temperature (Tm), and dynamic viscoelasticity of a commercially available bio-based polyester thermoplastic elastomer, "Arnitel (registered trademark) VT3108" (manufactured by DSM Engineering Materials), were measured. The results are shown in Table 2.

[0176] Comparative Example 3 The glass transition temperature (Tg), melting peak temperature (Tm), and dynamic viscoelasticity of a commercially available thermoplastic polyurethane elastomer, "Rezamin P2294" (manufactured by Dainichiseika Color & Chemicals Mfg. Co., Ltd.), were measured. The results are shown in Table 2.

[0177] [Example 8] A first reactor equipped with a stirrer, heat transfer jacket, vacuum pump, and reflux condenser was charged with 4.020 kg (approximately 1.476 mol) of PO3G2700-1, 2.680 kg (approximately 8.805 mol), 2.213 kg (approximately 10.33 mol), and a 3.0 mass% aqueous solution of calcium acetate monohydrate (as a catalyst) so that the calcium acetate monohydrate concentration was 100 μmol per mole of total dihydroxy compounds. The raw material mixture was then thoroughly purged with nitrogen (oxygen concentration: 0.0005-0.001 vol%). Next, the pressure inside the first reactor was reduced to 1.33 kPa (10 Torr), followed by a cycle of returning the pressure to atmospheric pressure with nitrogen. This cycle was repeated five times to purge the inside of the first reactor with nitrogen. After nitrogen purging, the internal temperature of the first reactor was gradually increased by passing a heat transfer medium at 230 °C through the heat transfer jacket, and the mixture was dissolved. The agitator was then rotated at 300 rpm, and the mixture was stirred for 1 hour. The temperature inside the heat medium jacket was controlled, and the internal temperature of the first reactor was gradually increased from 220°C until it reached 240°C approximately 1 hour after the start of stirring. The gauge pressure was then increased to 0.2 MPa, and the oligomer in the first reactor was pumped through a transfer pipe preheated to 200°C or higher into a second reactor equipped with a stirrer, heat medium jacket, vacuum pump, and reflux condenser, and having an internal temperature of 240°C. Next, the agitator for the raw material pumped into the second reactor was rotated at 33 rpm, and the pressure inside the second reactor was reduced from 101.3 kPa (760 Torr) to 13.3 kPa (100 Torr) absolute over 40 minutes, while distilling off phenol, a by-product of the oligomerization reaction of dihydroxy compounds and DPC occurring inside the second reactor. Next, the pressure in the second reactor was maintained at 13.3 kPa, and a transesterification reaction was carried out for 80 minutes while further distilling off phenol. The temperature was then increased, and the internal pressure was reduced from 13.3 kPa to 399 Pa (3 Torr) absolute over a further 40 minutes, and the distilled phenol was removed from the system. The temperature continued to be increased, and after the absolute pressure in the second reactor reached 70 Pa (approximately 0.5 Torr), the pressure was maintained at 70 Pa, and a polycondensation reaction was carried out. The final internal temperature in the second reactor was raised to 250°C, and when the agitator in the second reactor reached a predetermined agitation power, the polycondensation reaction was terminated, the reactor was repressurized with nitrogen, and the mixture was removed from the bottom of the reactor under pressure and cooled in a water-cooled tank to obtain a polycarbonate resin. The resulting polycarbonate resin was then blended with 74 ppm of butyl paratoluenesulfonate, melt-kneaded in a φ30 mm twin-screw extruder, and the strand-shaped product was cut in a pelletizer to obtain pelletized polycarbonate resin. The obtained polycarbonate resin contained 58.2 mass % of carbonate structural units (X) and 41.8 mass % of carbonate structural units (Y), and had a biomass content of 57.7 mass %.

[0178] The viscosity average molecular weight (Mv), glass transition temperature (Tg), and melting point peak temperature (Tm) of the polycarbonate resin thus obtained were measured. The resulting polycarbonate resin was kneaded at 220°C using a φ25mm counter-rotating twin-screw extruder equipped with a T-die, extruded through the T-die, and then cooled on a casting roll at approximately 60°C to obtain a film with a thickness of 300 μm. The resulting film was cut to the aforementioned size, and its dynamic viscoelasticity was measured. The results are shown in Table 3.

[0179] [Example 9] A raw material mixture was prepared by adding 4.690 kg (approximately 1.722 mol) of PO3G2700-1, 2.010 kg (approximately 6.604 mol), 1.801 kg (approximately 8.409 mol) of DPC, and a 3.0 mass% aqueous solution of calcium acetate monohydrate as a catalyst so that the calcium acetate monohydrate was 100 μmol per 1 mol of total dihydroxy compounds. Polycarbonate resin was produced by the same method as in Example 8, except that the external temperature of the reactor was not raised to 250°C when the pressure was reduced from 13.3 kPa (100 Torr) but was maintained at 240°C during the reaction, and 60 ppm of butyl paratoluenesulfonate was added to the polycarbonate resin. The obtained polycarbonate resin contained 68.5% by mass of carbonate structural units (X) and 31.5% by mass of carbonate structural units (Y), and had a biomass content of 67.8% by mass.

[0180] The viscosity average molecular weight (Mv), glass transition temperature (Tg), and melting peak temperature (Tm) of the polycarbonate resin thus obtained were measured. Furthermore, a film was produced by the same method as in Example 8, and the dynamic viscoelasticity was measured. The results are shown in Table 3.

[0181] [Example 10] A first reactor equipped with a stirrer, heat medium jacket, vacuum pump, and reflux condenser was charged with 4.020 kg (approximately 3.736 mol) of PO3G1000, 2.680 kg (approximately 8.805 mol), 2.713 kg (approximately 12.67 mol), and a 3.0 mass% aqueous solution of calcium acetate monohydrate as a catalyst, with the calcium acetate monohydrate added to a concentration of 150 μmol per mole of total dihydroxy compounds. The raw material mixture was then thoroughly purged with nitrogen (oxygen concentration: 0.0005-0.001 vol%). Next, the pressure inside the first reactor was reduced to 1.33 kPa (10 Torr), followed by a cycle of returning the pressure to atmospheric pressure with nitrogen. This cycle was repeated five times to purge the inside of the first reactor with nitrogen. After nitrogen purging, the internal temperature of the first reactor was gradually increased by passing a heat medium at 230 °C through the heat medium jacket, and the mixture was dissolved. Then, the agitator was rotated at 300 rpm, and the temperature in the heat medium jacket was controlled to maintain the internal temperature of the first reactor at 220 ° C. The gauge pressure was then increased to 0.2 MPa, and the oligomer in the first reactor was pressure-fed to a second reactor equipped with a stirrer, heat medium jacket, vacuum pump, and reflux condenser via a transfer pipe previously heated to 200 ° C or higher. The internal temperature was 220 ° C. The agitator was then rotated at 33 rpm to transfer the raw material pressured into the second reactor. The pressure in the second reactor was reduced from 101.3 kPa (760 Torr) to 13.3 kPa (100 Torr) absolute over 40 minutes while distilling off the phenol by-product of the oligomerization reaction of dihydroxy compound and DPC occurring inside the second reactor. The pressure in the second reactor was then maintained at 13.3 kPa, and the transesterification reaction was carried out for 80 minutes while further distilling off the phenol. The temperature was then increased, and the internal pressure was reduced from 13.3 kPa to 399 Pa (3 Torr) absolute over a period of 40 minutes, and the distilled phenol was removed from the system. The temperature was then continued to be increased, and after the absolute pressure in the second reactor reached 70 Pa (approximately 0.5 Torr), the pressure was maintained at 70 Pa, and the polycondensation reaction was carried out. The final internal temperature in the second reactor was raised to 240°C, and when the agitator of the second reactor reached a predetermined agitation power, the polycondensation reaction was terminated, the reactor was repressurized with nitrogen, and the mixture was then removed from the bottom of the reactor under pressure and cooled in a water-cooled tank to obtain a polycarbonate resin. The resulting polycarbonate resin was then blended with 128 ppm of butyl paratoluenesulfonate, melt-kneaded in a φ30 mm twin-screw extruder, and the strand-shaped mixture was cut in a pelletizer to obtain pelletized polycarbonate resin. The obtained polycarbonate resin contained 58.6 mass % of carbonate structural units (X) and 41.4 mass % of carbonate structural units (Y), and had a biomass content of 57.1 mass %.

[0182] The viscosity average molecular weight (Mv), glass transition temperature (Tg), and melting peak temperature (Tm) of the polycarbonate resin thus obtained were measured. Furthermore, a film was produced by the same method as in Example 8, and the dynamic viscoelasticity was measured. The results are shown in Table 3.

[0183] [Example 11] The polycarbonate resin synthesized in Example 10 was blended with 128 ppm of butyl paratoluenesulfonate and Micron White 5000S (talc manufactured by Hayashi Kasei Co., Ltd.) so that the blend amount was 1% by mass of the total resin composition. The blend was melt-kneaded in a φ30 mm twin-screw extruder, and the strand-shaped material was cut with a pelletizer to obtain pelletized polycarbonate resin. The obtained polycarbonate resin composition contained 58.0% by mass of carbonate structural units (X) and 41.0% by mass of carbonate structural units (Y), and had a biomass content of 56.5% by mass. The results are shown in Table 2.

[0184] The viscosity average molecular weight (Mv), glass transition temperature (Tg), and melting peak temperature (Tm) of the polycarbonate resin thus obtained were measured. Furthermore, a film was produced by the same method as in Example 8, and the dynamic viscoelasticity was measured. The results are shown in Table 3.

[0185] [Example 12] A raw material mixture was prepared by adding 4.690 kg (approximately 4.359 mol) of PO3G1000, 2.010 kg (approximately 6.604 mol), 2.372 kg (approximately 11.07 mol) of DPC, and a 3.0 mass% aqueous solution of calcium acetate monohydrate as a catalyst so that the calcium acetate monohydrate was 150 μmol per 1 mol of total dihydroxy compounds. A polycarbonate resin was produced by the method described in Example 10, except that 113 ppm of butyl paratoluenesulfonate was added to the polycarbonate resin. The obtained polycarbonate resin contained 68.8 mass % of carbonate structural units (X) and 31.2 mass % of carbonate structural units (Y), and had a biomass content of 67.0 mass %.

[0186] The viscosity average molecular weight (Mv), glass transition temperature (Tg), and melting peak temperature (Tm) of the polycarbonate resin thus obtained were measured. Furthermore, a film was produced by the same method as in Example 8, and the dynamic viscoelasticity was measured. The results are shown in Table 3.

[0187] [Table 2]

[0188] [Table 3]

[0189] Tables 2 and 3 show that by using the polycarbonate resin composition of the present invention, it is possible to provide a film for diaphragms that has excellent low-temperature properties (low-temperature mechanical strength), heat resistance, and flexibility, and that exhibits little change in elastic modulus, which is an indicator of flexibility, from low to high temperatures. In contrast, Comparative Example 1 does not contain the carbonate structural unit (Y) derived from the dihydroxy compound (2) that satisfies Requirement I, and therefore has a large E' (-30°C), poor flexibility, and a small E' (130°C) / E' (-30°C) ratio, meaning that the elastic modulus cannot be maintained over a wide temperature range. In other words, the sound quality is easily affected by temperature changes. Comparative Examples 2 and 3 used commercially available elastomers, and both had small E'(130°C) / E'(-30°C) values, meaning that the elastic modulus could not be maintained over a wide temperature range. In other words, the sound quality was prone to change with temperature changes.

Claims

1. A film for a diaphragm obtained using a polycarbonate resin composition, The polycarbonate resin composition contains carbonate structural units (X) derived from an aliphatic dihydroxy compound (1) represented by the following formula (1) and carbonate structural units (Y) derived from a dihydroxy compound (2) satisfying the following requirement I: The polycarbonate resin composition has a peak melting point temperature when the melting point peak temperature is measured by heating at a temperature increase rate of 20°C / min using a differential scanning calorimeter. <Requirement I> The polycarbonate resin (2) obtained by polymerizing the dihydroxy compound (2) and a carbonate source by a transesterification method has a peak melting point temperature when the peak melting point temperature is measured by heating at a temperature increase rate of 20°C / min using a differential scanning calorimeter. 【Chemical 1】 (In formula (1), X and Y are different from each other and each independently represent a single bond or a divalent linking group having 1 to 15 carbon atoms, 0 to 6 oxygen atoms, and 2 to 30 hydrogen atoms and not having a cyclic structure; and n is an integer of 2 to 100.)

2. The polycarbonate resin composition contains 1 to 99% by mass of the carbonate structural unit (X) and 1 to 99% by mass of the carbonate structural unit (Y), based on 100% by mass of all carbonate structural units. The film for diaphragms according to claim 1.

3. The polycarbonate resin composition contains 40 to 85 mass% of the carbonate structural unit (X) and 15 to 60 mass% of the carbonate structural unit (Y) in 100 mass% of all carbonate structural units. The film for diaphragms according to claim 2.

4. 2. The film for a diaphragm according to claim 1, wherein the number average molecular weight of the aliphatic dihydroxy compound (1) is 400 or more and 10,000 or less.

5. 2. The film for a diaphragm according to claim 1, wherein the aliphatic dihydroxy compound (1) is an aliphatic dihydroxy compound represented by the following formula (2): 【Chemistry 2】 (In formula (2), n is an integer from 2 to 100.)

6. The film for a diaphragm according to claim 1, wherein the dihydroxy compound (2) is any one of dihydroxy compounds represented by the following formulas (3) to (6): 【Chemistry 3】

7. The film for diaphragms according to claim 1, wherein the polycarbonate resin composition has a glass transition temperature of -100°C or higher and 30°C or lower.

8. 2. The film for diaphragms according to claim 1, wherein the polycarbonate resin composition has a peak melting point of 130°C or higher and 350°C or lower.

9. The film for diaphragms according to claim 1, wherein the storage modulus E' (-30°C) (unit: MPa) of the polycarbonate resin composition at -30°C as measured by dynamic viscoelasticity measurement is 0.1 or more and 700 or less.

10. 2. The film for diaphragms according to claim 1, wherein the polycarbonate resin composition has a storage modulus E' (130°C) (unit: MPa) at 130°C as measured by dynamic viscoelasticity measurement of 0.1 or more and 700 or less.

11. The polycarbonate resin composition according to claim 1, wherein the ratio E'(130°C) / E'(-30°C) of the storage modulus E'(-30°C) (unit: MPa) at 130°C to the storage modulus E'(-30°C) (unit: MPa) at -30°C measured by dynamic viscoelasticity measurement is 0.07 or more and 1.20 or less.

12. 2. The film for diaphragms according to claim 1, wherein the viscosity average molecular weight of the polycarbonate resin composition is 15,000 or more and 150,000 or less.

13. A diaphragm for acoustic equipment, which uses the diaphragm film according to any one of claims 1 to 12.

14. An acoustic device comprising the diaphragm for acoustic devices according to claim 13.

15. An electronic device comprising the acoustic device according to claim 14.

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