JP7336417B2 - Resin film for speaker diaphragm, manufacturing method thereof, and speaker diaphragm - Google Patents

Description

TECHNICAL FIELD The present invention relates to a resin film for a speaker diaphragm which is excellent in bass reproduction characteristics, heat resistance, etc., a method for producing the same, and a speaker diaphragm.

2. Description of the Related Art Mobile devices such as mobile phones, mobile game devices, smart phones, etc., have built-in small speakers called micro speakers. The diaphragm that generates the sound waves of the speaker called a microspeaker is generally made of (1) metal foil, (2) natural resin paper, woven fabric, or non-woven fabric, and (3) synthetic resin film. It is an important component that affects sound quality.

If the diaphragm is made of synthetic resin film (3) instead of (1) or (2), it has been used with polyethylene (PE) resin, polyolefin resin such as polypropylene (PP) resin, polyethylene terephthalate (PET). Films made of resins, polyester resins such as polyethylene naphthalate (PEN) resins, polyphenylene sulfide (PPS), polyetherimide (PEI) resins, etc. are used (see Patent Documents 1 and 2).

By the way, in recent years, speakers have become more and more advanced in functionality and performance. Therefore, the required characteristics of the speaker diaphragm are becoming more and more severe. The characteristics required for this diaphragm are light weight (low density or specific gravity), appropriate rigidity (Young's modulus, elastic modulus), excellent thickness accuracy, and high elongation at break. , and excellent durability. In addition to these properties, it also has excellent heat resistance, moisture resistance, water resistance, and moldability (press molding, vacuum molding, air pressure molding, etc.).

However, when the diaphragm of the speaker is made of the metal foil of (1), although it is excellent in heat resistance, moisture resistance, and water resistance, it has high density and rigidity, so the minimum resonance frequency (f ₀ ) is high, and the bass reproduction characteristics are poor. inadequate. In addition, when the speaker diaphragm is made of paper, woven fabric, or non-woven fabric made of natural resin as in (2), although the density is small and the weight is light, there are problems with heat resistance, moisture resistance, and water resistance, and the speaker manufacturing process also become complicated.

When the speaker diaphragm is made of a synthetic resin film of (3), specifically, a film made of polyolefin resin, it is lightweight, has a large loss tangent, and is excellent in moisture resistance, water resistance, and moldability. , Poor rigidity and problems with heat resistance. Also, when the diaphragm of the speaker is made of a film made of polyethylene terephthalate resin, it has better heat resistance than a film made of polyolefin resin, but the loss tangent is small and the sound quality is insufficient. In addition, since it deforms at a temperature of around 70° C., it cannot be said that the heat resistance is sufficient.

In addition, when the speaker diaphragm is made of polyethylene naphthalate resin film, the loss tangent and strength are large, the durability is excellent, and the sound quality characteristics are also excellent. , must be oriented. However, if the film is highly biaxially stretched and oriented, the rigidity (elastic modulus) of the film increases, so that the minimum resonance frequency (f ₀ ) increases, resulting in insufficient bass reproduction characteristics. In addition, the moldability of press molding, vacuum molding, air pressure molding, etc. may deteriorate.

In the case where the diaphragm of the speaker is a film made of polyphenyl sulfide resin, excellent heat resistance can be obtained if the film is highly biaxially stretched and oriented. However, if it is highly biaxially stretched and oriented, the minimum resonance frequency (f ₀ ) will increase, the low-frequency sound reproduction characteristics will become insufficient, and there is a risk of deterioration in moldability such as press molding, vacuum molding, and air pressure molding. . In addition, the loss tangent is small, which causes problems in sound quality.

In view of the above, films made of polyetherimide (PEI) resin and films made of polyetheretherketone (PEEK) resin have been proposed and used as diaphragm films (see Patent Documents 2, 3, and 4). .

Polyetherimide resin has a lower density and is lighter than polyethylene terephthalate resin, polyethylene naphthalate resin, and polyphenylene sulfide resin. In addition, since polyetherimide resin is an amorphous resin, when forming a film, it is more difficult to form a diaphragm than a film made of crystalline resin such as polyethylene terephthalate resin, polyethylene naphthalate resin, or polyphenylene sulfide resin. (diaphragm molding: press molding, air pressure molding, vacuum molding, etc.). Furthermore, since the polyetherimide resin film has a high loss tangent and excellent sound quality characteristics, it can be It is used for the diaphragm of automotive speakers.

JP-A-62-263797 JP-A-60-139098 JP-A-58-222699 JP-A-2007-43597

However, it has been reported that the heat resistance temperature of diaphragms made of polyetherimide resin films is 150° C. or less (Patent Document 3). Therefore, a film made of polyetherimide resin cannot obtain sufficient heat resistance. Furthermore, since the tensile elongation at break is small, there is a problem that the film is torn when the external output is increased.

On the other hand, it has been reported that the heat resistance temperature of the diaphragm obtained from the film made of polyetheretherketone resin is about 200 to about 300°C. Excellent in points. However, the elastic modulus (tensile elastic modulus) of the polyetheretherketone resin film is very large and exceeds 2800 N/mm ² . Therefore, the diaphragm obtained from this film has a high minimum resonance frequency (f ₀ ), resulting in insufficient bass reproduction.

The present invention has been made in view of the above. Another object of the present invention is to provide a speaker diaphragm.

Means for Solving the Problems As a result of intensive studies aimed at solving the above problems, the present inventors have focused on the combination of a polyarylene ether ketone resin and an adhesive fluororesin, and completed the present invention.

That is, in order to solve the above-mentioned problems, the present invention is characterized by being molded from a molding material containing 100 parts by mass of polyarylene ether ketone resin and 1 part by mass or more and 100 parts by mass or less of adhesive fluororesin. .

It is preferable that the tensile modulus at 23°C is 100 N/mm ² or more and 2500 N/mm ² or less, and the tensile elongation at break at 23°C is 50% or more.
Moreover, it is preferable that the loss tangent at 20°C is 0.010 or higher, and the first inflection point temperature of the storage elastic modulus after cooling is 130°C or higher.

Further, in order to solve the above problems, the present invention provides a method for manufacturing a resin film for a speaker diaphragm according to claim 1, 2, or 3, comprising:
100 parts by mass of polyarylene ether ketone resin and 1 part by mass or more and 100 parts by mass or less of adhesive fluororesin are melt-kneaded to prepare a molding material. It is characterized in that it is extruded into a resin film, and this diaphragm resin film is brought into contact with a cooling roll to be cooled.

In order to solve the above-mentioned problems, the present invention is characterized in that the resin film for a speaker diaphragm described in claim 1, 2 or 3 and an elastomer layer having a thickness of 10 μm or more and 100 μm or less are laminated. and

The elastomer layer is a silicone resin, and the durometer hardness of the silicone resin is preferably A10 or more and A90 or less when measured with a durometer type A according to JIS K 6253.
Further, it is preferable that a primer layer is interposed between the silicone resin and the diaphragm resin film.

Here, the resin film for a diaphragm in the scope of claims is not particularly limited to transparent, opaque, translucent, unstretched resin film, uniaxially stretched resin film, and biaxially stretched resin film. This diaphragm resin film can be laminated on one side or both sides of the elastomer layer. Any one of an antistatic agent layer, an elastomer layer, and a metal layer can be laminated on the diaphragm resin film, if necessary. In addition, speakers are mainly built in mobile devices, and mobile devices include at least mobile phones, mobile music devices, mobile game devices, smart phones, tablet PCs, laptop computers, and the like.

According to the present invention, since the molding material contains a polyarylene ether ketone resin, it is possible to obtain a resin film for a diaphragm that is excellent in toughness, heat resistance, solvent resistance, and the like. In addition, since the molding material is prepared from polyarylene ether ketone resin and adhesive fluororesin, it is possible to obtain excellent sound quality characteristics by suppressing the occurrence of resonance and increasing loss tangent as well as bass characteristics.

According to the present invention, it is possible to obtain excellent heat resistance and sound quality characteristics, and moreover, it is possible to prevent complication of the speaker manufacturing process.

According to the second aspect of the invention, the resin film for diaphragm has a tensile modulus of elasticity of 100 N/mm ² or more and 2500 N/mm ² or less at 23° C. Therefore, handling performance during processing of the speaker is deteriorated, and high-pitched sound reproduction is deteriorated. Insufficiency can be prevented, and moreover, bass reproduction can be satisfied. Further, since the tensile elongation at break of the diaphragm resin film at 23° C. is 50% or more, there is little risk of troubles such as breakage or cracking during processing of the diaphragm resin film, which facilitates production. Moreover, it is possible to prevent the durability of the diaphragm of the diaphragm resin film from deteriorating.

According to the third aspect of the invention, since the loss tangent of the diaphragm resin film at 20° C. is 0.010 or more, it is possible to prevent poor sound quality caused by resonance. In addition, since the first inflection point temperature of the storage modulus of the resin film for diaphragm after cooling is 130° C. or more, sufficient heat resistance can be obtained, and the diaphragm obtained from the resin film for diaphragm can be used as a speaker. When used, it is possible to prevent deterioration in durability such as deformation, cracking, or breakage of the diaphragm obtained from the diaphragm resin film due to high heat accompanying high vibration of the voice coil.

According to the fourth aspect of the present invention, since the melt extrusion molding method is adopted for manufacturing the diaphragm resin film, it is possible to achieve ease of handling of the diaphragm resin film and simplification of equipment.

According to the fifth aspect of the invention, a resin film obtained by adding an adhesive fluororesin to a polyarylene ether ketone resin having an appropriate tensile modulus is used, so that the diaphragm of a high-performance loudspeaker excellent in bass reproduction and treble reproduction is used. can be obtained. Further, a resin film for a diaphragm, which is obtained by adding an adhesive fluororesin to a polyarylene ether ketone resin, can realize a speaker diaphragm having a small specific gravity, a light weight, and excellent heat resistance. In addition, it is possible to prevent the compression set property of the elastomer layer from deteriorating and the vibration propagation velocity of the diaphragm of the speaker to decrease, thereby preventing the sound quality from being degraded.

According to the sixth aspect of the invention, it is possible to suppress the deterioration of the compression set property of the silicone resin of the elastomer layer and the decrease of the vibration propagation speed of the diaphragm of the speaker. Moreover, it is possible to prevent deterioration of the performance of the diaphragm due to a decrease in the loss tangent.
According to the seventh aspect of the present invention, the diaphragm resin film and the silicone resin of the elastomer layer can be firmly adhered to each other, and separation of the diaphragm resin film and the silicone resin can be prevented.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is an overall explanatory view schematically showing an embodiment of a speaker diaphragm resin film and a method for producing the same according to the present invention. 4 is a graph schematically showing the relationship between the first inflection point temperature and the storage elastic modulus in the example of the method for producing a resin film for a speaker diaphragm according to the present invention. FIG. 5 is an explanatory view schematically showing a second embodiment of a speaker diaphragm resin film and a speaker diaphragm according to the present invention.

Preferred embodiments of the present invention will now be described with reference to the drawings. As shown in FIG. It is a resin film molded from a molding material 1 containing .

The molding material 1 is prepared by containing 100 parts by mass of a polyarylene ether ketone resin and 1 to 100 parts by mass of an adhesive fluororesin. This molding material 1 contains a polyarylene ether ketone resin, an adhesive fluororesin, an antioxidant, a light stabilizer, an ultraviolet absorber, a plasticizer, a lubricant, a flame retardant, and an electrifier as long as the properties of the present invention are not impaired. Inhibitors, heat resistance improvers, inorganic compounds, organic compounds, resin modifiers, etc. are selectively added.

The polyarylene ether ketone resin of the molding material 1 is a crystalline resin composed of an arylene group, an ether group, and a carbonyl group. Super engineering plastics growing in advanced applications: PEEK (above)], etc., which are excellent in mechanical properties, heat resistance, and water resistance.

Specific examples of the polyarylene ether ketone resin include, for example, a polyether ether ketone (PEEK) resin having a chemical structural formula represented by the chemical formula (1), a polyether ketone having a chemical structure represented by the chemical formula (2) ( PEK) resin, polyether ketone ketone (PEKK) resin having a chemical structure represented by chemical formula (3), polyether ether ketone ketone (PEEKK) resin having a chemical structure represented by chemical formula (4), or chemical formula (5) Polyether ketone ether ketone ketone (PEKEKK) resin having a chemical structure, and the like.

Among these polyarylene ether ketone resins, polyether ether ketone resins and polyether ketone ketone resins are preferred from the viewpoint of availability, cost, and moldability of resin films. Specific examples of polyether ether ketone resins include Victrek's product name: Victrex Powder series and Victrex Granules series, Daicel-Evonik's product name: Vestakeep series, and Solvay Specialty Polymers' product name: KetaSpire. The PEEK series can be mentioned. A specific example of the polyether ketone ketone resin is the KEPSTAN series manufactured by Arkema.

The polyarylene ether ketone resin may be used singly or in combination of two or more. Also, the polyarylene ether ketone resin may be a copolymer having two or more chemical structures represented by chemical formulas (1) to (5). Polyarylene ether ketone resins are usually used in a form suitable for molding, such as powder, granules, or pellets. In addition, the method for producing the polyarylene ether ketone resin is not particularly limited, but for example, the production method described in the document [Asahi Research Center Co., Ltd.: Super engineering plastic PEEK growing in advanced applications (above)]. can give.

The adhesive fluororesin has a repeating unit (a) based on tetrafluoroethylene (hereinafter referred to as TFE) and/or chlorotrifluoroethylene (hereinafter referred to as CTFE), a dicarboxylic anhydride group, and in the ring Repeating unit (b) based on a cyclic hydrocarbon monomer having a polymerizable unsaturated group, and repeating based on other monomers (excluding repeating units (a) and (b) if they overlap) Contains unit (c).

In the adhesive fluororesin, the repeating unit (a) is 50 to 99.89 mol% with respect to the total molar amount of the repeating unit (a), the repeating unit (b), and the repeating unit (c), the repeating unit (b ) is 0.01 to 5 mol %, and the repeating unit (c) is 0.1 to 49.99 mol %. Preferably, the repeating unit (a) is 50 to 99.47 mol%, the repeating unit (b) is 0.03 to 3 mol%, and the repeating unit (c) is 0.5 to 49.97 mol%, more preferably contains 50 to 98.95 mol % of repeating unit (a), 0.05 to 2 mol % of repeating unit (b), and 1 to 49.95 mol % of repeating unit (c).

This is because the heat resistance and chemical resistance of the adhesive fluororesin are improved when the mol% of the repeating unit (a), the repeating unit (b), and the repeating unit (c) are in the range. Also, if the mol % of the repeating unit (b) is within the range, the adhesive fluororesin will have excellent adhesiveness to the crystalline polyarylene ether ketone resin. Furthermore, if the mol % of the repeating unit (c) is within the range, the adhesive fluororesin will be excellent in mechanical properties such as moldability and stress crack resistance.

The "cyclic hydrocarbon monomer having a dicarboxylic anhydride group and a polymerizable unsaturated group in the ring" (hereinafter simply referred to as a cyclic hydrocarbon monomer) has one or more five-membered rings or six A polymerizable compound which is a cyclic hydrocarbon consisting of a membered ring and has a dicarboxylic anhydride group and an intracyclic polymerizable unsaturated group.

As cyclic hydrocarbons, cyclic hydrocarbons having one or more bridged polycyclic hydrocarbons are preferred. That is, a cyclic hydrocarbon consisting of a bridged polycyclic hydrocarbon, a cyclic hydrocarbon in which two or more bridged polycyclic hydrocarbons are condensed, or a cyclic hydrocarbon in which a bridged polycyclic hydrocarbon and another cyclic hydrocarbon are condensed Preferably. In addition, this cyclic hydrocarbon monomer has one or more intracyclic polymerizable unsaturated groups, ie, one or more polymerizable unsaturated groups present between carbon atoms constituting a hydrocarbon ring. The cyclic hydrocarbon monomer further has a dicarboxylic anhydride group (--CO--O--CO--), and the dicarboxylic anhydride group may be bonded to two carbon atoms constituting the hydrocarbon ring, and the ring It may be bonded to two outer carbon atoms.

Preferably, the dicarboxylic anhydride group is a carbon atom that constitutes the ring of the cyclic hydrocarbon and bonds to two adjacent carbon atoms. Furthermore, instead of hydrogen atoms, halogen atoms, alkyl groups, halogenated alkyl groups, and other substituents may be bonded to the carbon atoms that constitute the ring of the cyclic hydrocarbon. Specific examples include those represented by the following formulas (6) to (13). Here, R in formulas (7) and (10) to (13) is a halogen atom selected from a lower alkyl group having 1 to 6 carbon atoms, a fluorine atom, a chlorine atom, a bromine atom, and an iodine atom; A halogenated alkyl group in which a hydrogen atom in a lower alkyl group is substituted with a halogen atom.

As the cyclic hydrocarbon monomer, preferably represented by formula (6), 5-norbornene-2,3-dicarboxylic anhydride (hereinafter referred to as NAH), represented by formulas (8) and (9) Cyclic hydrocarbon monomers that are acid anhydrides, formulas (7), and formulas (10) to (13) include cyclic hydrocarbon monomers in which the substituent R is a methyl group. NAH is more preferable.

Other monomers include vinyl fluoride, vinylidene fluoride (hereinafter referred to as VdF), CTFE (except when used as repeating unit (a)), trifluoroethylene, hexafluoropropylene (hereinafter referred to as HFP ), CF ₂ ═CFOR ^{f 1} (wherein R ^{f 1} is a perfluoroalkyl group having 1 to 10 carbon atoms and which may contain an oxygen atom between carbon atoms), CF ₂ ═CFOR ^{f 2} SO ₂ X ¹ (R ^{f 2} is a perfluoroalkylene group having 1 to 10 carbon atoms which may contain an oxygen atom between carbon atoms, X ¹ is a halogen atom or a hydroxyl group), CF ₂ =CFOR ^{f 2} CO ₂ X ² (wherein R ^{f 2} is the above X ² is a hydrogen atom or an alkyl group having 1 to 3 carbon atoms), CF ₂ =CF(CF ₂ ) _p OCF=CF ₂ (where p is 1 or 2), CH ₂ =CX ³ (CF ₂ ) _q X ⁴ (where X ³ and X ⁴ are each independently a hydrogen atom or a fluorine atom, q is an integer of 2 to 10), perfluoro(2-methylene-4-methyl-1,3-dioxolane ), olefins having 2 to 4 carbon atoms such as ethylene, propylene and isobutene, vinyl esters such as vinyl acetate, and vinyl ethers such as ethyl vinyl ether and cyclohexyl vinyl ether. Other monomers may be used singly or in combination of two or more.

Specific examples of _CF2 = _CFOR ^f1 include _{CF2 = CFOCF2CF3 , CF2} = _{CFOCF2CF2CF3 , CF2} = _{CFOCF2CF2CF2CF3 , CF2 =} CFO( _CF2 ) ₈ F and the like. _{Preferably , CF2} = _CFOCF2CF2CF3 . Further, as specific examples of _CH2 = _CX3 ( _CF2 ) _qX4 ^, for example, _CH2 =CH( _CF2 ) _2F , _CH2 =CH( _CF2 ) _3F , _CH2 =CH( _CF2 ) ₄ F, CH ₂ =CF(CF ₂ ) ₃ H, CH ₂ =CF(CF ₂ ) ₄ H and the like. Preferably _CH2 =CH( _CF2 ) _4F or _CH2 =CH( _CF2 ) _2F .

Other monomers preferably include VdF, HFP, CTFE (except when used as repeating unit (a)), CF ₂ =CFOR ^{f 1} , CH ₂ =CX ₃ (CF ₂ ) _q X ⁴ , One or more selected from the group consisting of ethylene, propylene, and vinyl acetate, more preferably HFP, CTFE (except when used as repeating unit (a)), CF ₂ =CFOR ^{f 1} , It is one or more selected from the group ^consisting of ethylene and _CH2 = ^CX3 ( _CF2 ) _qX4 . Most preferably HFP or CF ₂ =CFOR ^{f 1} . As CF ₂ =CFOR ^{f 1} , R ^{f 1} is preferably a perfluoroalkyl group having 1 to 6 carbon atoms, more preferably a perfluoroalkyl group having 2 to 4 carbon atoms, and most preferably a perfluoropropyl group.

Specific examples _of the adhesive fluororesin include TFE/ _CF2 = _CFOCF2CF2CF3 /NAH copolymer, TFE _{/ HFP} /NAH copolymer, TFE/ _CF2 = _{CFOCF2CF2CF3 /} HFP/NAH copolymer, TFE/VdF/NAH copolymer, TFE/ _CH2 =CH( _CF2 ) _4F /NAH/ethylene copolymer, TFE/ _CH2 =CH( _CF2 ) _2F /NAH /ethylene copolymer, CTFE/ _CH2 =CH( _CF2 ) _4F /NAH/ethylene copolymer, CTFE/ _CH2 =CH( _CF2 ) _2F /NAH/ethylene copolymer, CTFE/ _CH2 ═CH(CF ₂ ) ₂ F/NAH/ethylene copolymer and the like.

The melting point of the adhesive fluororesin is preferably 150° C. or higher and 330° C. or lower, more preferably 200° C. or higher and 320° C. or lower. This melting point can be prepared by appropriately selecting the content ratio of the repeating unit (a), the repeating unit (b), and the repeating unit (c) within the above range.
As the polymer terminal group of the adhesive fluororesin, if it has an adhesive functional group such as an ester group, a carbonate group, a hydroxyl group, a carboxyl group, a carbonyl fluoride group, or an acid anhydride residue, crystals other than the adhesive fluororesin It is preferable because it is excellent in adhesiveness with a thermoplastic polyimide resin having a high viscosity. Moreover, the polymer terminal group having an adhesive functional group can be introduced by appropriately selecting a radical polymerization initiator, a chain transfer agent, etc. during the production of the adhesive fluororesin.

A method for producing the adhesive fluororesin is not particularly limited, but a radical polymerization method using a radical polymerization initiator is used. Examples of this polymerization method include bulk polymerization, solution polymerization using organic solvents such as fluorocarbons, chlorinated hydrocarbons, fluorochlorohydrocarbons, alcohols and hydrocarbons, aqueous media, and, if necessary, suitable organic solvents. Suspension polymerization to be used, aqueous medium, and emulsion polymerization to use an emulsifier can be mentioned, but solution polymerization is particularly desirable.

The adhesive fluororesin is not particularly limited, but is preferably the adhesive fluororesin described in Japanese Patent No. 4424246, Japanese Patent No. 5263269, Japanese Patent No. 5365939, or Japanese Patent Application Laid-Open No. 2019-43134. can give. Specific examples of this adhesive fluororesin include LH-8000 [manufactured by AGC: product name], AH-5000 [manufactured by AGC: product name], AH-2000 [manufactured by AGC: product name] EA-2000, etc. [manufactured by AGC: product name]. Among these adhesive fluororesins, EA-2000, which is excellent in heat resistance, is suitable.

The amount of the adhesive fluororesin added is 1 part by mass or more and 100 parts by mass or less, preferably 10 parts by mass or less and 90 parts by mass or less, more preferably 15 parts by mass or more and 80 parts by mass or less per 100 parts by mass of the polyarylene ether ketone resin. and more preferably 20 parts by mass or more and 60 parts by mass or less. This is because if the amount added is less than 1 part by mass, the tensile modulus of the diaphragm resin film 2 cannot be expected to decrease. Since the dispersibility of the resin and the adhesive fluororesin is reduced and the tensile elongation at break of the diaphragm resin film 2 is reduced, the handleability during processing of the portable device speaker is deteriorated, and the diaphragm resin film 2 This is because the durability of the diaphragm is reduced, and if the external output is increased, the diaphragm is torn or cracked.

From the above, if the amount of the adhesive fluororesin added is in the range of 1 part by mass or more and 100 parts by mass or less, the lowest resonance frequency (f ₀ ) is lowered, the bass reproduction characteristics are excellent, and handling properties and durability are improved. A speaker diaphragm resin film 2 capable of preventing deterioration is obtained.

In the molding material 1, in addition to the above resins, polyimide resins such as polyimide (PI) resins, polyamideimide (PAI) resins, polyetherimide (PEI) resins, polyamide 4T (PA4T) resins, polyamide 6T (PA6T) resins other than the above resins. ) resin, modified polyamide 6T (PA6T) resin, polyamide 9T (PA9T) resin, polyamide 10T (PA10T) resin, polyamide 11T (PA11T) resin, polyamide 6 (PA6) resin, polyamide 66 (PA66) resin, polyamide 46 (PA46 ) resins such as polyamide resins, polyethylene terephthalate (PET) resins, polybutylene terephthalate (PBT) resins, polyester resins such as polyethylene naphthalate (PEN) resins, polysulfone (PSU) resins, polyether sulfone (PES) resins, poly Polysulfone resin such as phenylsulfone (PPSU) resin, polyphenylene sulfide (PPS) resin, polyphenylene sulfide ketone resin, polyphenylene sulfide sulfone resin, polyarylene sulfide resin such as polyphenylene sulfide ketone sulfone resin, liquid crystal polymer (LCP), polycarbonate (PC ) resin, polyarylate (PAR) resin, etc. are added as necessary.

In the above, when manufacturing the resin film 2 for the speaker diaphragm, first, as shown in FIG. After preparing the molding material 1 by kneading, the molding material 1 is continuously molded into a belt-shaped speaker diaphragm resin film 2 .

(1) A polyarylene ether ketone resin and an adhesive fluororesin are stirred and mixed at room temperature (0° C. or higher and 50° C. or lower), and then melt-kneaded to form a diaphragm resin film 2. (2) adding an adhesive fluororesin to a molten polyarylene ether ketone resin without stirring and mixing the polyarylene ether ketone resin and the adhesive fluororesin; a method of preparing the molding material 1 by

Any of these methods can be adopted. First, the method (1) will be explained. When stirring and mixing the polyarylene ether ketone resin and the adhesive fluororesin, a tumbler mixer, a Hensil mixer, a V-type mixer, a Nauta mixer, a ribbon blender, or A universal stirring mixer or the like is used.

The polyarylene ether ketone resin and the adhesive fluororesin are mixed by mixing rolls, pressure kneaders, Banbury mixers, planetary mixers, twin-screw extruders, tri-screw extruders, and four-screw extruders. , a multi-screw extruder such as an eight-screw extruder, or the like, to prepare a molding material 1 by melt-kneading and dispersing. When the molding material 1 is prepared, the temperature during melt kneading by the melt kneader is 300° C. or higher and 400° C. or lower, preferably 330° C. or higher and 380° C. or lower. This is because if the melt-kneading temperature of the melt extruder 10 exceeds 400° C., the adhesive fluororesin is violently decomposed, which is undesirable.

Next, the method (2) will be described. In this method, a polyarylene ether ketone resin is mixed with a mixing roll, a pressure kneader, a Banbury mixer, a planetary mixer, a twin-screw extruder, and a tri-screw extruder. , a four-screw extruder, an eight-screw extruder, and other multi-screw extruders, etc., and by adding an adhesive fluororesin to the melted polyarylene ether ketone resin and dispersing it by melt-kneading, polyarylene A molding material 1 of ether ketone resin and adhesive fluororesin is prepared. When preparing the molding material 1 comprising a polyarylene ether ketone resin and an adhesive fluororesin, the temperature during melt kneading by a melt kneader is preferably 300° C. or higher and 400° C. or lower, preferably 330° C. or higher and 380° C. or lower. This is because when the temperature of the melt extruder 10 exceeds 400° C., the adhesive fluororesin is violently decomposed as described above.

The molding material 1 is usually extruded into lumps, strands, sheets, or rods, and then processed into powder, granules, pellets, or other forms suitable for molding using a crusher or a cutter.

The diaphragm resin film 2 made of the molding material 1 can be produced by a known method such as a melt extrusion molding method, a force renderer molding method, or a casting molding method. Here, the melt extrusion molding method uses a melt extruder 10 such as a single-screw extruder or a twin-screw extruder to melt the molding material 1 of the polyarylene ether ketone resin and the adhesive fluororesin. In this method, the mixture is kneaded and continuously extruded from a T-die 13 at the tip of a melt extruder 10 to form a band-shaped diaphragm resin film 2 . From the standpoint of ease of handling and simplification of equipment, melt extrusion molding is the most suitable method for manufacturing the resin film 2 for diaphragm.

The melt extruder 10 is, for example, a single-screw extruder, a twin-screw extruder, or the like, and functions to melt-knead the molding material 1 that is charged. A raw material inlet 11 for the molding material 1 is installed in the upper rear part of the melt extruder 10, and the raw material inlet 11 contains helium gas, neon gas, argon gas, krypton gas, nitrogen gas, and carbon dioxide gas. An inert gas supply pipe 12 is connected to supply an inert gas such as a is prevented.

As the melt extruder 10 such as a single-screw extruder or a twin-screw extruder, it is preferable to use a melt extruder 10 having a vent port. This is because the use of the vent port for melt-kneading under reduced pressure makes it easier to sufficiently deaerate moisture and sublimated organic matter contained in the molding material 1 . Also, it is not necessary to adjust the moisture content of the molding material 1 before melt-kneading.

The temperature during melt kneading in the melt extruder 10 is not particularly limited as long as it is a temperature at which the molding material 1 can be melted and the temperature at which the molding material 1 does not decompose. A range below the decomposition temperature is good. Specifically, the temperature is adjusted to 300° C. or higher and 400° C. or lower, preferably 330° C. or higher and 380° C. or lower. This is because, if the temperature is less than 300°C, the molding material 1 containing the polyarylene ether ketone resin cannot be melt-extruded, and if it exceeds 400°C, the adhesive fluoropolymer violently decomposes. Because it is possible.

The molding material 1 melt-kneaded by the melt extruder 10 is continuously extruded into a band-shaped diaphragm resin film 2 by a T-die 13 at the tip of the melt extruder 10, and this continuous diaphragm is formed. The resin film 2 for use is sandwiched between a pair of pressing rolls 17 and a cooling roll 18 below, cooled, and then wound by a winder 19.

The T-die 13 is attached to the tip of the melt extruder 10 through a connecting pipe 14 and functions to continuously push out the belt-shaped diaphragm resin film 2 downward. The temperature of the T-die 13 during extrusion is in the range of the melting point of the molding material 1 or more and less than the thermal decomposition temperature. Specifically, the temperature is adjusted to 300° C. or higher and 400° C. or lower, preferably 330° C. or higher and 380° C. or lower. This is because if the temperature is less than 300°C, the molding material 1 containing the polyarylene ether ketone resin cannot be melt-extruded, and if the temperature exceeds 400°C, the adhesive fluororesin may violently decompose. because there is

A gear pump 15 and a filter 16 are preferably attached to the connecting pipe 14 upstream of the T-die 13 . The gear pump 15 transfers the molding material 1 melted and kneaded by the melt extruder 10 to the T-die 13 at a constant flow rate and with high accuracy through the filter 16 . The filter 16 separates gel and foreign matter from the molten molding material 1 and transfers the molten molding material 1 to the T-die 13 .

A pair of pressure rollers 17 are rotatably supported below the T-die 13 and sandwich a cooling roller 18 so as to be in sliding contact therewith. and cool. A winding tube 20 of a winder 19 for winding the diaphragm resin film 2 is rotatably installed further downstream of the downstream pressure roll 17 of the pair of pressure rolls 17 . Between the winding tube 20 of the take-up machine 19 and a slit blade 21 that forms a slit in the side portion of the resin film for diaphragm 2 is disposed so as to be able to move up and down. A necessary number of rotatable tension rolls 22 are axially supported between the take-up tube 20 and the tension rolls 22 for applying tension to the diaphragm resin film 2 to smoothly take up the film.

From the viewpoint of improving the adhesion between the diaphragm resin film 2 and the cooling roll 18, the peripheral surface of each pressing roll 17 is coated with at least a rubber layer of natural rubber, isoprene rubber, butadiene rubber, silicone rubber, fluororubber, or the like. A film is formed as necessary, and an inorganic compound such as silica or alumina is selectively added to this rubber layer. Among these, it is preferable to adopt silicone rubber and fluororubber, which are excellent in heat resistance.

As the pressing roll 17, a metal elastic roll having a metal surface is used as necessary. When this metal elastic roll is used, it is possible to form the diaphragm resin film 2 having an excellent smooth surface. Become. Specific examples of metal elastic rolls include metal sleeve rolls, air rolls [manufactured by Dymco Corporation: product name], and UF rolls [manufactured by Hitachi Zosen Corporation: product name].

Such a pressure roller 17 is adjusted to a temperature of 50° C. or higher and 260° C. or lower, preferably 100° C. or higher and 240° C. or lower, more preferably 130° C. or higher and 220° C. or lower, still more preferably 150° C. or higher and 200° C. or lower. The plate resin film 2 is slidably contacted and pressed against the cooling roll 18 . The reason for the temperature range of the pressure roll 17 is that if the temperature of the pressure roll 17 exceeds 260° C., the diaphragm resin film 2 during production sticks to the pressure roll 17 and breaks. Alternatively, the rubber layer covering the pressing roll 17 may be thermally decomposed.

Conversely, if the temperature of the pressure roll 17 is less than 50° C., condensation will occur on the pressure roll 17, which is not preferable. As a method for temperature adjustment and cooling of the pressing roll 17, a method using a heat medium such as air, water, oil, or the like, an electric heater, dielectric heating, or the like can be used.

The cooling roll 18 is made of, for example, a metal roll having a larger diameter than the pressing roll 17 , and is rotatably supported below the T-die 13 so that the extruded diaphragm resin film 2 is narrowed between the pressing roll 17 and the cooling roll 18 . While cooling the diaphragm resin film 2 together with the pressing roll 17, the thickness thereof is controlled within a predetermined range. The cooling roll 18 is heated to a temperature of 50° C. to 260° C., preferably 100° C. to 240° C., more preferably 130° C. to 220° C., still more preferably 150° C. to 200° C. It is adjusted and comes into sliding contact with the diaphragm resin film 2 .

The reason why the temperature of the cooling roll 18 is adjusted to 50° C. or more and 260° C. or less is that when the temperature of the cooling roll 18 exceeds 260° C., the diaphragm resin film 2 during manufacture is in close contact with the cooling roll 18 . This is because the diaphragm resin film 2 may be broken, or in the case of the pressing roll 17 coated with a rubber layer, the rubber layer of the pressing roll 17 may be thermally decomposed. On the other hand, if the temperature of the cooling roll 18 is less than 50° C., condensation will occur on the cooling roll 18, which is not preferable. The temperature adjustment and cooling method of the cooling roll 18 include a method using a heat medium such as air, water, oil, etc., an electric heater, induction heating, and the like.

In the above configuration, when more specifically and actually manufacturing the diaphragm resin film 2, as shown in FIG. , the polyarylene ether ketone resin of the molding material 1 and the adhesive fluororesin are melt-kneaded by the melt extruder 10, and the diaphragm resin film 2 is passed through the T-die 13. is continuously extruded into strips. At this time, the water content of the molding material 1 before melt extrusion is adjusted to 2000 ppm or less, preferably 1000 ppm or less, more preferably 100 ppm or more and 500 ppm or less. This is because if the moisture content exceeds 2000 ppm, the molding material 1 may foam immediately after being extruded from the T-die 13 .

After the diaphragm resin film 2 is extruded, it is sequentially wound around a pair of compression rolls 17 , a cooling roll 18 , a tension roll 22 , and a winding tube 20 of a winder 19 , and the diaphragm resin film 2 is rolled by the cooling roll 18 . After cooling, both sides of the diaphragm resin film 2 are cut by slit blades 21, respectively, and the resin film 2 for the diaphragm of the portable device speaker is produced by sequentially winding it around the winding tube 20 of the winding machine 19. can do. When manufacturing the diaphragm resin film 2, the surface of the diaphragm resin film 2 is formed with fine irregularities within a range that does not lose the effect of the present invention, and the friction coefficient of the surface of the diaphragm resin film 2 is increased. can be lowered.

The thickness of the diaphragm resin film 2 is not particularly limited as long as it is 2 μm or more and 1000 μm or less. 100 μm or less, more preferably 3 μm or more and 95 μm or less, and still more preferably 8 μm or more and 75 μm or less.

This is because if the thickness of the diaphragm resin film 2 is less than 2 μm, the mechanical strength of the diaphragm resin film 2 is significantly reduced, making it difficult to mold the diaphragm resin film 2 . be. Conversely, if the thickness of the diaphragm resin film 2 exceeds 100 μm, the molding accuracy of the diaphragm is lowered. The thickness of the diaphragm resin film 2 can be measured with various micrometers. The thickness tolerance of the diaphragm resin film 2 should be within the range of the average value ±5%, preferably within the range of the average value ±3%. This is because if the thickness tolerance of the diaphragm resin film 2 is out of the range of ±5% of the average value, the sound quality will vary, which is not preferable. The thickness tolerance of the diaphragm resin film 2 can be obtained by the following formula.

Film thickness tolerance [%] = {(MAX or MIN) - (AVE)} / (AVE) x 100
where, MAX: maximum value of film thickness
MIN: Minimum film thickness
AVE: Average value of film thickness

The mechanical properties of the diaphragm resin film 2 can be evaluated by the tensile elongation at break at 23° C. and the tensile elastic modulus. The tensile elongation at break is preferably 50% or more, preferably 100% or more, more preferably 150% or more, and still more preferably 200% or more, as measured according to JIS K 6251 or 7127. Although the upper limit of the tensile elongation at break is not particularly limited, it is preferably 500% or less.

This is because if the elongation at break is less than 50%, the diaphragm resin film 2 does not have sufficient toughness, and troubles such as breakage and cracking occur during processing of the diaphragm resin film 2 . This is because there is a fear that the manufacturing will be difficult. Another reason is that the durability of the diaphragm of the diaphragm resin film 2 is lowered, and the diaphragm is torn or cracked when the external output is increased.

The tensile elastic modulus of the diaphragm resin film 2 at 23° C. is 100 N/mm ² or more and 2500 N/mm ² or less, preferably 300 N/mm ² or more and 2000 N/mm ² by a measurement method based on JIS K 6251 or JIS K 7127. Below, more preferably 500 N/mm ² or more and 1500 N/mm ² or less, and still more preferably 500 N/mm ² or more and 1000 N/mm ² or less is optimal. This is because if the tensile modulus of the diaphragm resin film 2 is less than 100 N/mm ² , the rigidity of the diaphragm resin film 2 is inferior, resulting in deterioration in handleability during processing of the mobile phone speaker and vibration. This is because the high-frequency resonance frequency (f _H ) of the diaphragm of the plate resin film 2 is low, resulting in insufficient reproduction of high-pitched sounds. On the other hand, if it exceeds 2500 N/mm ² , the minimum resonance frequency (f ₀ ) of the diaphragm obtained from the resin film 2 for diaphragm is high, and bass reproduction becomes insufficient.

The heat resistance of the diaphragm resin film 2 can be evaluated by the first inflection point temperature of the storage elastic modulus (see FIG. 2). Here, the first inflection point temperature of the storage modulus is the temperature at which the storage modulus appears at a temperature of 25° C. or higher and at a temperature of 9.0×10 ⁹ Pa or higher.

The first inflection point temperature of the storage elastic modulus that appears at a temperature of 25° C. or higher in the diaphragm resin film 2 is 130° C. or higher, preferably 140° C. or higher, and more preferably 145° C. or higher. This is because when the first inflection point temperature of the storage elastic modulus of the diaphragm resin film 2 is less than 130° C., the heat resistance of the diaphragm resin film 2 is insufficient, and When the obtained diaphragm is used as a speaker, the high heat associated with the high vibration of the voice coil causes deformation, cracking, or breakage of the diaphragm obtained from the diaphragm resin film 2, resulting in deterioration in durability. is. Although the upper limit of the first inflection point temperature of the storage elastic modulus of the diaphragm film is not particularly limited, it is preferably 250° C. or less.

The loss tangent of the diaphragm resin film 2 at 20° C. is 0.010 or more, preferably 0.013 or more, more preferably 0.015 or more, and still more preferably 0.018 in order to prevent resonance and obtain good sound quality. The above is optimal. This is because when the loss tangent is less than 0.010, resonance occurs and good sound quality cannot be obtained. Although the upper limit of the loss tangent is not particularly restricted, it is preferably 0.45 or less.

The specific gravity of the diaphragm resin film 2 after cooling is optimally 1.1 to 1.8, preferably 1.3 to 1.6, and more preferably 1.4 to 1.5. This is because within such a range, the density is low, so weight reduction can be achieved, and good sound quality characteristics can be obtained.

The front and rear surfaces of the resin film 2 for diaphragm can be formed with minute unevenness to reduce the coefficient of friction. As a method for forming the fine unevenness, (1) the diaphragm resin film 2 is sandwiched between the pressing roll 17 having the fine unevenness and the cooling roll 18 having the fine unevenness to form the fine unevenness. (2) A method of forming fine unevenness by spraying fine inorganic compounds such as zirconia, glass, stainless steel, etc., polycarbonate resins, polyamide resins, or organic compounds such as plant seeds on the resin film 2 for diaphragm, ( 3) A method of press-molding the diaphragm resin film 2 with a mold having fine unevenness to form fine unevenness can be mentioned. Among these methods, the method (1) is the most suitable from the viewpoints of simplification of equipment, accuracy of unevenness size, uniformity of unevenness formation, ease of unevenness formation, and continuous formation of unevenness. .

The method (1) will be explained in more detail. and sandwiching the discharged product between the cooling roll 18 and the compression roll 17 having fine unevenness on the peripheral surface, and molding the diaphragm resin film 2 at the same time as the melt extrusion molding. (1-2) A method in which the molded resin film 2 for diaphragm is sandwiched between a press roll 17 having fine unevenness on its peripheral surface and a cooling roll 18 having fine unevenness on its peripheral surface to form unevenness. Among these, the method (1-1) is preferable from the viewpoint of simplification of equipment.

According to the above configuration, since the molding material 1 contains the polyarylene ether ketone resin, it is possible to obtain the diaphragm resin film 2 having excellent toughness, heat resistance, solvent resistance, and the like. Further, it is also possible to add an adhesive fluororesin having excellent dispersibility to the molding material 1 to improve the slipperiness of the front and rear surfaces of the diaphragm resin film 2 . Specifically, the slipperiness of the surface of the diaphragm resin film 2 can be evaluated by a static friction coefficient and a dynamic friction coefficient. The static friction coefficient can be reduced to 0.40 or less, preferably 0.38 or less, and the dynamic friction coefficient can be reduced to 0.30 or less, preferably 0.25 or less. When the diaphragm resin film 2 is wound by the winder 19, wrinkles do not occur. Therefore, it is possible to effectively solve the problem that the diaphragm resin film 2 is broken or damaged during manufacturing or secondary processing.

The lower limits of elongation at static friction coefficient and dynamic friction coefficient are not particularly limited, but are preferably 0.10 or more.

In addition, instead of fluororesin such as tetrafluoroethylene/perfluoroalkoxyethylene copolymer, an adhesive fluororesin that is highly compatible with polyarylene ether ketone resin is used, so that the diaphragm resin film 2 is melt extruded. It becomes possible to manufacture smoothly by the method. In addition, since the molding material 1 is prepared from the polyarylene ether ketone resin and the adhesive fluororesin, it is possible to obtain excellent sound quality characteristics in which the loss tangent is increased and the occurrence of resonance is suppressed, in addition to the bass characteristics. Become. Therefore, important bass sounds can be emphasized and reproduced by the portable device without relying on the software of the portable device or without connecting a dedicated external speaker to the portable device.

In addition, since improvement in bass characteristics can be expected without making the speaker large and heavy, it is possible to contribute to the demand for thinner, smaller, and lighter portable equipment. Further, since the diaphragm resin film 2 having excellent heat resistance is used for the portable device speaker, excellent heat resistance can be expected. Furthermore, since the diaphragm resin film 2 containing crystalline polyarylene ether ketone resin, which has excellent heat dissipation properties, is used, the loss is reduced and stable long-term use of the diaphragm resin film 2 can be expected.

Next, FIG. 3 shows a second embodiment of the present invention. In this case, a pair of diaphragm resin films 2 are prepared, and a thickness An elastomer layer 31 having a thickness of 10 μm or more and 100 μm or less is sandwiched and adhered to form a speaker diaphragm 30 having a laminated structure.

Examples of elastomers for the elastomer layer 31 include silicone resins, urethane resins, acrylic resins, fluorine resins, polyester resins, polyamide resins, hydrocarbon resins, styrene resins, vinyl chloride resins, and vinyl acetate resins. Among these elastomers, silicone resins, particularly heat-curable silicone resins, are preferable because they are excellent in heat resistance, weather resistance, flame retardancy, sound quality characteristics, compression characteristics, and the like. Examples of heat-curable silicone resins include addition-curable millable silicone resins and addition-curable liquid silicone resins.

Addition-curing millable silicone resins are usually composed of organopolysiloxane, a silica-based filler, and a curing agent (a known curing agent obtained by combining a platinum-based catalyst and an organohydrogenpolysiloxane, and an organic peroxide, etc.). ) and various additives such as silica fine powder are used in the form of a composition.

In contrast, the addition-curable liquid silicone resin contains an organopolysiloxane containing at least two silicon-bonded alkenyl groups per molecule and at least two silicon-bonded hydrogen atoms per molecule. and an inorganic filler having an average particle diameter of 1 μm or more and 30 μm or less and a bulk density of 0.1 g/cm ³ or more and 0.5 g/cm ³ or less (diatomaceous earth, perlite, pulverized perlite foam) , mica, calcium carbonate, glass flakes, hollow fillers, etc.) and addition reaction catalysts (platinum black, platinic chloride, chloroplatinic acid, reactants of chloroplatinic acid and monohydric alcohols, chloroplatinic acid and olefins complex with, platinum bisacetoacetate, palladium-based catalyst, rhodium-based catalyst, etc.) is added in the form of a resin composition.

The durometer hardness of the silicone resin when the silicone resin is used for the elastomer layer 31 is A10 or more and A90 or less, preferably A20 or more and A70 or less, more preferably A20 or more and A70 or less, when measured with a durometer type A according to JIS K 6253. A range of A20 or more and A50 or less is optimal. This is because if the durometer hardness is less than A10, the compression set characteristic of the silicone resin is deteriorated, or the vibration propagation speed of the diaphragm 30 is lowered, resulting in a problem of sound quality. Conversely, if the durometer hardness exceeds A90, the loss tangent becomes small and the performance of the diaphragm 30 deteriorates.

A primer layer 32 is selectively interposed between the pair of diaphragm resin films 2 and the elastomer layer 31 for the purpose of firmly bonding them together. Each primer layer 32 is interposed between the facing surfaces of the diaphragm resin film 2 and the silicone resin of the elastomer layer 31, and functions to firmly bond them.

The primer layer 32 is not particularly limited as long as it can bond the silicone resin of the elastomer layer 31 and the diaphragm resin film 2, but for example, alkyd resin, phenol-modified, silicone-modified, etc. Modified alkyd resins, oil-free alkyd resins, acrylic resins, silicone resins, epoxy resins, fluorine resins, phenolic resins, silane coupling agents, titanate coupling agents, aluminum coupling agents, mixtures thereof, and the like. Examples of cross-linking agents for curing and/or cross-linking these resins include isocyanate compounds, melamine compounds, epoxy compounds, peroxides, phenol compounds, hydrogensiloxane compounds and silane compounds.

Each primer layer 32 has a thickness of 0.1 μm or more and 5 μm or less, preferably 1 μm or more and 3 μm or less. This is because when the thickness of the primer layer 32 is less than 0.1 μm, the adhesion between the elastomer layer 31 and the diaphragm resin film 2 is insufficient, and peeling occurs during molding into the diaphragm 30 or during use. This is because there is a risk that On the other hand, if the thickness of the primer layer 32 exceeds 5 μm, the secondary moldability of the diaphragm 30 or the acoustic characteristics may be adversely affected.

In this embodiment, the same effect as in the above embodiment can be expected, and since the diaphragm 30 of the speaker is not made of metal foil, the minimum resonance frequency (f ₀ ) can be lowered to obtain sufficient bass reproduction characteristics. can be done. Moreover, since the diaphragm 30 is not made of paper, woven fabric, or non-woven fabric made of natural resin, excellent resistance to moisture, water, and heat can be obtained, and the manufacturing process of the speaker can be simplified and facilitated. can be planned. In addition, since the resin film 2 for a diaphragm made by adding an adhesive fluororesin to a polyarylene ether ketone resin having an appropriate tensile modulus is excellent in reproducing low and high frequencies, it is possible to obtain a diaphragm 30 for a high-performance speaker. can be done.

Further, the resin film 2 for a diaphragm made by adding an adhesive fluororesin to a polyarylene ether ketone resin makes it possible to realize a diaphragm 30 for a speaker which is light in weight and excellent in heat resistance and has a small specific gravity. Furthermore, it is clear that deterioration of the compression set property of the elastomer layer 31 and deterioration of the vibration propagation velocity of the diaphragm 30 of the loudspeaker can be effectively prevented from causing problems in sound quality.

The surface of the diaphragm resin film 2 in the above embodiment may be coated with various antistatic agents, silicone resins, acrylic resins, urethane resins or other elastomers, or may be coated with aluminum as long as the effects of the present invention are not lost. , various metals such as tin, nickel, and copper may be vapor-deposited. Also, the shape of the opening of the filter 16 is not particularly limited, and may be circular, elliptical, rectangular, polygonal, or the like.

Examples of a resin film for a speaker diaphragm and a method for producing the same according to the present invention will be described below together with comparative examples.
[Example 1]
First, a molding material was prepared from a polyarylene ether ketone resin and an adhesive fluororesin. As the polyarylene ether ketone resin, 100 parts by mass of commercially available polyether ether ketone resin [manufactured by Solvay Specialty Polymers, product name: KETASPIRE KT-851 NL SP (hereinafter abbreviated as "KT-851 NL SP"). The polyether ether ketone resin was dried for 12 hours or longer in a dehumidifying dryer heated to 160°C. As the adhesive fluororesin, 5 parts by mass of a commercially available adhesive fluororesin EA-2000 (manufactured by AGC: product name, hereinafter abbreviated as “EA-2000”) was prepared.

After preparing these, the two types of resins are put into a mixer and stirred and mixed to prepare a stirred mixture, and the stirred mixture is melt-kneaded with a co-rotating twin-screw extruder or the like and extruded into a strand shape, After the extruded product was air-cooled and solidified, it was cut into pellets to prepare a molding material. A co-rotating twin-screw extruder of φ42 mm, L/D=38 type was used. The stirred mixture was melt-kneaded under conditions of a cylinder temperature of 370°C and a die temperature of 370°C to prepare a molding material. The temperature during melt-kneading was determined by measuring the temperature of the molding material in a molten state immediately after being extruded from the die.

Next, the molding material is put into a dehumidifying dryer heated to 160 ° C. and dried for 12 hours or more. After confirming that the moisture content of the dried molding material is 300 ppm or less, the dried molding material is passed through a T-die with a width of 900 mm. The molding material was put into a single-screw extruder equipped with an attachment and melt-kneaded, and the melt-kneaded molding material was continuously extruded through a T-die to extrusion-mold a resin film for a speaker diaphragm into a belt shape. At this time, the water content of the polyether ketone ketone resin was measured by the Karl Fischer titration method using a trace water content analyzer (trade name: CA-100, manufactured by Mitsubishi Chemical Corporation).

The single-screw extruder had a diameter of 40 mm and a screw: full flight screw (L/D=32, compression ratio: 2.5) type. The cylinder temperature of this single-screw extruder was adjusted to 250 to 390°C, the temperature of the T-die was adjusted to 390°C, and the temperatures of the connecting pipe connecting the single-screw extruder and the T-die, the gear pump, and the filter were each adjusted to 390°C. As for the temperature of the molten molding material, the temperature of the resin at the inlet of the T-die was measured, and it was 393°C. Further, when the molding material was put into the single-screw extruder, nitrogen gas was supplied at 18 L/min through an inert gas supply pipe.

After extrusion molding of the resin film for the diaphragm of the speaker, the resin film for the diaphragm is passed through a pair of pressure bonding rolls made of silicone rubber, metal rolls that are cooling rolls having a temperature of 150° C. with unevenness on the peripheral surface, and downstream of these. It is sequentially wound on a 6-inch winding tube of a winding machine located in , sandwiched between a crimping roll and a metal roll, and sequentially wound on the winding tube of the winding machine to obtain a length of 100 m and a width of 650 mm. We manufactured a resin film for speaker diaphragms.

After the speaker diaphragm resin film was produced, the film thickness, mechanical properties, heat resistance properties, and acoustic properties of the diaphragm resin film were evaluated. The mechanical properties of the diaphragm resin film are the elongation at break and the tensile elastic modulus, the heat resistance is the first inflection point temperature of the storage elastic modulus of the diaphragm resin film, and the acoustic properties are the 20°C of the diaphragm resin film. and the loss tangent at .

·Thickness of resin film for diaphragm The film thickness of the resin film for diaphragm was measured using a micrometer [manufactured by Mitutoyo, product name: coolant proof micrometer code MDC-25PJ]. In the measurement, measurements were taken at arbitrary 10 points in the width direction (perpendicular direction to the extrusion direction) of the diaphragm resin film, and the average value thereof was taken as the film thickness.

• Mechanical Properties of Diaphragm Resin Film The mechanical properties of the diaphragm resin film were evaluated by tensile elongation at break and tensile elastic modulus. The tensile elongation at break and tensile elastic modulus were measured according to JIS K 7127 (specimen type 1B) under conditions of a tensile speed of 50 mm/min and a temperature of 23°C. The tensile modulus was measured in the extrusion direction and width direction (perpendicular to the extrusion direction) of the film.

- First Inflection Point Temperature of Storage Elastic Modulus of Resin Film for Diaphragm The heat resistance of the resin film for diaphragm was evaluated by the first inflection point temperature of the storage elastic modulus. The first inflection point temperature of the storage elastic modulus was measured in the extrusion direction and width direction (perpendicular to the extrusion direction) of the diaphragm resin film. Specifically, when measuring the storage elastic modulus of the diaphragm resin film, the size is 60 mm in the extrusion direction×6 mm in the width direction, and when measuring the storage elastic modulus in the width direction, the size is 6 mm in the extrusion direction×60 mm in width. Cut out and measured.

When measuring the storage elastic modulus, the tensile mode using a viscoelastic spectrometer (product name: RSA-G2 manufactured by TS Instrument Japan) was measured at a frequency of 1 Hz, a strain of 0.1%, and a heating rate of Measurement was carried out under the conditions of 3°C/min, a measurement temperature range of 0°C to 360°C, and a check interval of 21 mm.

The first inflection point temperature, as shown in FIG. 2, was taken as the temperature at the intersection of two extended straight lines with respect to the change curve of storage modulus. Specifically, first, the straight line portion before the first sharp drop in the storage modulus is extended to the high temperature side, and the first straight line (a) is drawn. Next, a second straight line (b) is drawn by extending the straight line after the first sharp drop in storage modulus to the low temperature side. After that, a vertical line at the intersection of both lines (a) and (b) was drawn on the temperature axis of the horizontal axis, and that temperature was obtained as the first inflection point temperature.

- Loss Tangent of Resin Film for Diaphragm The loss tangent of the resin film for diaphragm was measured in the extrusion direction and the width direction (perpendicular to the extrusion direction). Specifically, when measuring the loss tangent in the extrusion direction of the resin film for diaphragm, 60 mm in the extrusion direction × 6 mm in the width direction, and when measuring the loss tangent in the width direction, 6 mm in the extrusion direction × 60 mm in the width direction It was cut to size and measured. When measuring the loss tangent, the tensile mode using a viscoelastic spectrometer (product name: RSA-G2 manufactured by TS Instrument Japan) was used at a frequency of 1 Hz, a strain of 0.1%, and a heating rate of 3. C./min, measurement temperature range of 0.degree. C. to 360.degree.

[Example 2]
First, a molding material was prepared from a polyarylene ether ketone resin and an adhesive fluororesin. In Example 1, KT-851 NL SP was used as the commercially available polyetheretherketone resin. It was changed to J ZV7403 (hereinafter abbreviated as "ZV7403"). As a molding material, 100 parts by mass of polyetheretherketone resin was prepared, and this polyetheretherketone resin was dried for 12 hours or longer in a dehumidifying dryer heated to 160°C. As the adhesive fluororesin, 15 parts by mass of the adhesive fluororesin EA-2000 used in Example 1 was prepared.

After these were prepared, a molding material was prepared in the same manner as in Example 1. The temperature during melt-kneading was determined by measuring the temperature of the molding material in a molten state immediately after being extruded from the die.

Next, the molding material was put into a dehumidifying dryer heated to 160 ° C. and dried for 12 hours or more, and the moisture content of the dried molding material was measured by the same method as in Example 1. The moisture content of the dried molding material was confirmed to be 300 ppm or less, a resin film for a speaker diaphragm was produced in the same manner as in Example 1. Regarding the temperature of the molten molding material, the temperature of the resin at the inlet of the T-die was measured, and it was 393°C. The temperature of the cooling roll was changed to 210°C.

After the speaker diaphragm resin film was produced, the film thickness, mechanical properties, heat resistance properties, and acoustic properties of this diaphragm resin film were evaluated according to the method of Example 1, and the results are summarized in Table 1.

[Example 3]
First, a molding material was prepared from a polyarylene ether ketone resin and an adhesive fluororesin. In Example 1, KT-851 NL SP was used as the commercially available polyetheretherketone resin. (hereinafter abbreviated as "381G"). As a molding material, 100 parts by mass of polyetheretherketone resin was prepared, and this polyetheretherketone resin was dried for 12 hours or longer in a dehumidifying dryer heated to 160°C. As the adhesive fluororesin, 30 parts by mass of the adhesive fluororesin EA-2000 used in Example 1 was prepared.

After these were prepared, a molding material was prepared in the same manner as in Example 1. The temperature during melt-kneading was determined by measuring the temperature of the molding material in a molten state immediately after being extruded from the die.

Next, the molding material was put into a dehumidifying dryer heated to 160 ° C. and dried for 12 hours or more, and the moisture content of the dried molding material was measured by the same method as in Example 1. The moisture content of the dried molding material was confirmed to be 300 ppm or less, a resin film for a speaker diaphragm was produced in the same manner as in Example 1.

Regarding the temperature of the molten molding material, the temperature of the resin at the inlet of the T-die was measured, and it was 393°C. The temperature of the cooling roll was the same as in Example 1. After the speaker diaphragm resin film was produced, the film thickness, mechanical properties, heat resistance properties, and acoustic properties of this diaphragm resin film were evaluated according to the method of Example 1, and the results are summarized in Table 1.

[Example 4]
First, a molding material was prepared from a polyarylene ether ketone resin and an adhesive fluororesin. In Example 1, KT-851 NL SP was used as the commercially available polyetheretherketone resin, but in Example 4, the commercially available polyetheretherketone resin was Victrex Granules 450G, a product name manufactured by Victrex. (hereinafter abbreviated as "450G"). As a molding material, 100 parts by mass of polyetheretherketone resin was prepared, and this polyetheretherketone resin was dried for 12 hours or longer in a dehumidifying dryer heated to 160°C. As the adhesive fluororesin, 50 parts by mass of the adhesive fluororesin EA-2000 used in Example 1 was prepared.

After these were prepared, a molding material was prepared in the same manner as in Example 1. The temperature during melt-kneading was determined by measuring the temperature of the molding material in a molten state immediately after being extruded from the die.

Next, the molding material was put into a dehumidifying dryer heated to 160 ° C. and dried for 12 hours or more, and the moisture content of the dried molding material was measured by the same method as in Example 1. The moisture content of the dried molding material was confirmed to be 300 ppm or less, a resin film for a speaker diaphragm was produced in the same manner as in Example 1. As for the temperature of the molten molding material, the temperature of the resin at the inlet of the T-die was measured, and it was 390°C. The temperature of the cooling roll was the same as in Example 1.

After the speaker diaphragm resin film was produced, the film thickness, mechanical properties, heat resistance properties, and acoustic properties of this diaphragm resin film were evaluated according to the method of Example 1, and the results are summarized in Table 1.

[Example 5]
First, a molding material was prepared from a polyarylene ether ketone resin and an adhesive fluororesin. In Example 5, the polyetheretherketone resin used in Example 1 was used as the commercially available polyetheretherketone resin. As a molding material, 100 parts by mass of polyetheretherketone resin was prepared, and this polyetheretherketone resin was dried for 12 hours or longer in a dehumidifying dryer heated to 160°C. As the adhesive fluororesin, 85 parts by mass of the adhesive fluororesin EA-2000 used in Example 1 was prepared.

After these were prepared, a molding material was prepared in the same manner as in Example 1. The temperature during melt-kneading was determined by measuring the temperature of the molding material in a molten state immediately after being extruded from the die.

Next, the molding material was put into a dehumidifying dryer heated to 160 ° C. and dried for 12 hours or more, and the moisture content of the dried molding material was measured by the same method as in Example 1. The moisture content of the dried molding material was confirmed to be 300 ppm or less, a resin film for a speaker diaphragm was produced in the same manner as in Example 1. Regarding the temperature of the molten molding material, the temperature of the resin at the inlet of the T-die was measured, and it was 391°C. The temperature of the cooling roll was the same as in Example 1.

After manufacturing the resin film for the diaphragm of the speaker, the film thickness, mechanical properties, heat resistance and acoustic properties of the resin film for the diaphragm were evaluated according to the method of Example 1, and the results are summarized in Table 2.

[Example 6]
First, a molding material was prepared from a polyarylene ether ketone resin and an adhesive fluororesin. As the polyarylene ether ketone, a commercially available polyether ketone ketone resin [Product name: KEPSTAN 6003 (hereinafter referred to as "KEPSTAN 6003"] manufactured by Arkema) was used.As the molding material, 100 parts of polyether ketone ketone resin were prepared. , This polyether ketone ketone resin was dried for 12 hours or longer in a dehumidifying dryer heated to 160° C. As the adhesive fluororesin, commercially available adhesive fluororesin EA-2000 [manufactured by AGC: product name , (hereinafter abbreviated as “EA-2000”) was prepared in an amount of 30 parts by mass.

After preparing these, the two types of resins are put into a mixer and stirred and mixed to prepare a stirred mixture, and the stirred mixture is melt-kneaded with a co-rotating twin-screw extruder or the like and extruded into a strand shape, After the extruded product was air-cooled and solidified, it was cut into pellets to prepare a molding material. A co-rotating twin-screw extruder of φ25 mm, L/D=41 type was used. The stirred mixture was melt-kneaded under conditions of a cylinder temperature of 385°C and a die temperature of 385°C to prepare a molding material. The temperature during melt-kneading was determined by measuring the temperature of the molding material in a molten state immediately after being extruded from the die.

Next, the molding material is put into a dehumidifying dryer heated to 160 ° C. and dried for 12 hours or more. After confirming that the moisture content of the dried molding material is 300 ppm or less, the dried molding material is passed through a T-die with a width of 150 mm. The molding material was put into a single-screw extruder equipped with an attachment and melt-kneaded, and the melt-kneaded molding material was continuously extruded through a T-die to extrusion-mold a resin film for a speaker diaphragm into a belt shape. At this time, the water content of the polyether ketone ketone resin was measured by the Karl Fischer titration method using a trace water content analyzer (trade name: CA-100, manufactured by Mitsubishi Chemical Corporation).

The single-screw extruder had a diameter of 20 mm and a screw: full-flight screw (L/D=25, compression ratio: 2.5) type. The cylinder temperature of the single-screw extruder was adjusted to 360°C to 380°C, the temperature of the T-die was adjusted to 400°C, and the temperature of the connecting pipe connecting the single-screw extruder and the T-die was adjusted to 380°C. As for the temperature of the molten molding material, the temperature of the resin at the inlet of the T-die was measured, and it was 377°C.

After extrusion molding of the resin film for the diaphragm of the speaker, the resin film for the diaphragm is passed through a pair of pressure bonding rolls made of silicone rubber, a metal roll that is a cooling roll at 160° C., and a winder located downstream of these. By sequentially winding on a 3-inch winding tube, pinching between a compression roll and a metal roll, cutting both sides of the continuous diaphragm resin film with a slit blade, and sequentially winding on the winding tube, A speaker diaphragm resin film having a length of 10 m and a width of 130 mm was manufactured. When charging the molding material into the single-screw extruder, nitrogen gas was supplied at 18 L/min through an inert gas supply pipe.

After the speaker diaphragm resin film was produced, the film thickness, mechanical properties, heat resistance, and acoustic properties of the diaphragm resin film were evaluated according to the method of Example 1, and the results are shown in Table 2. The mechanical properties of the diaphragm resin film were evaluated by the tensile elongation at break and the tensile modulus. Measurement was performed at a speed of 50 mm/min and a temperature of 23°C. The tensile elongation at break and the tensile elastic modulus were measured in the extrusion direction and width direction (perpendicular to the extrusion direction) of the diaphragm resin film.

[Comparative Example 1]
First, a molding material was prepared from a polyarylene ether ketone resin and an adhesive fluororesin. The same polyetheretherketone resin as in Example 1 was used as the polyaryleneetherketone resin. As a molding material, 100 parts by mass of polyetheretherketone resin was prepared, and this polyetheretherketone resin was dried for 12 hours in a dehumidifying dryer heated to 160°C. As the adhesive fluororesin, 0.5 parts by mass of the adhesive fluororesin EA-2000 used in Example 1 was prepared.

After these were prepared, a molding material was prepared in the same manner as in Example 1. The temperature during melt-kneading was determined by measuring the temperature of the molding material in a molten state immediately after being extruded from the die.

Next, the molding material was put into a dehumidifying dryer heated to 160 ° C. and dried for 24 hours, and the moisture content of the dried molding material was measured by the same method as in Example 1. After confirming that the content was 300 ppm or less, a resin film for a speaker diaphragm was produced in the same manner as in Example 1. Regarding the temperature of the molten molding material, the temperature of the resin at the inlet of the T-die was measured, and it was 391°C. The temperature of the cooling roll was set in the same manner as in Example 1.

After the speaker diaphragm resin film was produced, the film thickness, tensile modulus, heat resistance, and acoustic characteristics of the diaphragm resin film were evaluated according to the method of Example 1, and the results are shown in Table 3.

[Comparative Example 2]
First, a molding material was prepared from a polyarylene ether ketone resin and an adhesive fluororesin. The same polyetheretherketone resin as in Example 3 was used as the polyaryleneetherketone resin. As a molding material, 100 parts by mass of polyetheretherketone resin was prepared, and this polyetheretherketone resin was dried for 12 hours in a dehumidifying dryer heated to 160°C. As the adhesive fluororesin, 130 parts by mass of the adhesive fluororesin EA-2000 used in Example 1 was prepared.

After these were prepared, a molding material was prepared in the same manner as in Example 1. The temperature during melt-kneading was determined by measuring the temperature of the molding material in a molten state immediately after being extruded from the die.

Next, the molding material was put into a dehumidifying dryer heated to 160 ° C. and dried for 24 hours, and the moisture content of the dried molding material was measured by the same method as in Example 1. After confirming that the content was 300 ppm or less, a resin film for a speaker diaphragm was produced in the same manner as in Example 1. As for the temperature of the molten molding material, the temperature of the resin at the inlet of the T-die was measured, and it was 390°C. The temperature of the cooling roll was set in the same manner as in Example 1.

After the speaker diaphragm resin film was produced, the film thickness, tensile modulus, heat resistance, and acoustic characteristics of the diaphragm resin film were evaluated according to the method of Example 1, and the results are shown in Table 3.

[Comparative Example 3]
First, a molding material was prepared from a polyarylene ether ketone resin and a tetrafluoroethylene/perfluoroalkoxyethylene copolymer (hereinafter abbreviated as "PFA resin"), which is a non-adhesive fluororesin. KT-851NL SP, the same as in Example 4, was used as the polyarylene ether ketone resin. As a molding material, 100 parts by mass of polyetheretherketone resin was prepared, and this polyetheretherketone resin was dried for 12 hours in a dehumidifying dryer heated to 160°C. As the PFA resin, 15 parts by mass of commercially available Neoflon AP-201 [manufactured by Daikin Industries, Ltd.: product name (hereinafter abbreviated as "AP-201")] was prepared.

After these were prepared, a molding material was prepared in the same manner as in Example 1. The cylinder temperature of the co-rotating twin-screw extruder was changed to 380°C, and the die temperature was changed to 380°C. As for the temperature during melt-kneading, the temperature of the molding material in a molten state immediately after being extruded from the die was measured.

Next, the molding material was put into a dehumidifying dryer heated to 160 ° C. and dried for 24 hours, and the moisture content of the dried molding material was measured by the same method as in Example 1. After confirming that the concentration was 300 ppm or less, a resin film for a speaker diaphragm was produced in the same manner as in Example 1. Regarding the temperature of the molten molding material, the temperature of the resin at the inlet of the T-die was measured, and it was 389°C. The temperature of the cooling roll was the same as in Example 1.

After the speaker diaphragm resin film was produced, the film thickness, tensile modulus, heat resistance, and acoustic characteristics of the diaphragm resin film were evaluated according to the method of Example 1, and the results are shown in Table 3.

[Results]
The resin film for the diaphragm of each example was changed from the polyetheretherketone resin film of Comparative Example 1 and the adhesive fluororesin of Comparative Example 3 to the PFA resin, which is a fluororesin having no adhesiveness, to the polyetheretherketone resin. Compared with the resin film for a diaphragm obtained by addition, the tensile elastic modulus shows a low tensile elastic modulus of 850 N/mm ² or more and 2260 N/mm ² or less, and is presumed to be excellent in bass reproduction characteristics. On the other hand, in the case of Comparative Examples 1 and 3, since the tensile elastic modulus exceeds 2800 N/mm ² , it is presumed that the bass reproduction characteristics are insufficient.

The loss tangent at 20° C. of the diaphragm resin film obtained in each example increased to 0.014 or more, and it was possible to obtain good sound quality characteristics by suppressing the occurrence of resonance. Further, unlike Comparative Example 2, the tensile elongation at break of the diaphragm resin film of each example was 86% or more, confirming sufficient durability. The first inflection point temperature of each example is 140° C. or more, and it is presumed that the film has sufficient heat resistance to be used as a diaphragm resin film.

On the other hand, in the case of Comparative Example 1, since no adhesive fluororesin was added, the tensile modulus of the diaphragm resin film exhibited a high tensile modulus of 2800 N/mm ² or more, indicating low-frequency reproduction characteristics. and the loss tangent at 20°C was less than 0.010. As a result, the occurrence of resonance could not be suppressed, and good sound quality could not be obtained.

In the case of Comparative Example 2, 150 parts by mass of the adhesive fluororesin was added to 100 parts by mass of the crystalline thermoplastic polyimide resin. When the resin film was used for the diaphragm, there was a problem with durability. In addition, the handleability was poor, and a problem arose in the formability of the diaphragm of the speaker.

In the case of Comparative Example 3, the diaphragm resin film to which the PFA resin, which is a non-adhesive fluororesin, was added had a tensile modulus of elasticity exceeding 2800 N/mm ² and an increased f ₀ value.
From the above results, the polyarylene ketone resin film to which the adhesive fluororesin is added has an appropriate tensile elastic modulus. In addition to heat resistance, it is presumed to be excellent in sound quality characteristics.

INDUSTRIAL APPLICABILITY The resin film for a speaker diaphragm, the method for manufacturing the same, and the speaker diaphragm according to the present invention are used in the field of manufacturing audio equipment, portable equipment, and the like.

1 Molding Material 2 Resin Film for Diaphragm 10 Melt Extruder 13 T Die (Dice)
17 compression roll 18 cooling roll 19 winder 30 diaphragm 31 elastomer layer 32 primer layer

Claims (7)

A resin film for a diaphragm of a speaker, characterized by being molded from a molding material containing 100 parts by mass of a polyarylene ether ketone resin and 1 to 100 parts by mass of an adhesive fluororesin. 2. The resin film for speaker diaphragm according to claim 1, having a tensile modulus at 23[deg.]C of 100 N/mm ^<2> or more and 2500 N/mm ^<2> or less and a tensile elongation at break of 50% or more at 23[deg.]C. 3. The resin film for a speaker diaphragm according to claim 1, wherein the loss tangent at 20[deg.] C. is 0.010 or higher, and the temperature of the first inflection point of the storage elastic modulus after cooling is 130[deg.] C. or higher. A method for producing a resin film for a speaker diaphragm according to claim 1, 2, or 3,
100 parts by mass of polyarylene ether ketone resin and 1 part by mass or more and 100 parts by mass or less of adhesive fluororesin are melt-kneaded to prepare a molding material. A method for producing a resin film for a speaker diaphragm, comprising extruding a resin film into a resin film and contacting the resin film for a diaphragm with a cooling roll to cool the film. 4. A loudspeaker diaphragm, wherein the resin film for a loudspeaker diaphragm according to claim 1, 2 or 3 and an elastomer layer having a thickness of 10 [mu]m to 100 [mu]m are laminated. 6. The speaker diaphragm according to claim 5, wherein the elastomer layer is a silicone resin, and the durometer hardness of the silicone resin is A10 or more and A90 or less when measured with a durometer type A according to JIS K6253. 7. The speaker diaphragm according to claim 6, wherein a primer layer is interposed between the silicone resin and the diaphragm resin film.

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