JP5397242B2 - Laminated polyphenylene sulfide film. - Google Patents

Description

The present invention relates to a laminated polyphenylene sulfide film excellent in heat resistance, workability, and frequency characteristics, and various acoustic devices using the film, that is, a film for an acoustic device diaphragm or an acoustic device diaphragm constituting a speaker.

Conventionally, polyphenylene sulfide films have been used as electrical insulating materials, capacitor materials, and building materials because of their heat resistance, electrical characteristics, and flame retardancy. Also, it is preferably used as an acoustic device diaphragm because it exhibits high frequency characteristics.
In general, a polyethylene terephthalate (hereinafter abbreviated as PET) film is used as an acoustic device diaphragm made of plastic. In addition, a laminated film (hereinafter abbreviated as ZV film) in which resin layers containing aromatic polyimide are laminated on both sides of PET is disclosed.

When used for small-diameter speakers, such as small radio speakers, headphones speakers, etc., acoustic device diaphragms using PET are susceptible to thermal deformation in an atmosphere of 65 ° C or higher, and thus generate abnormal sounds. There was a fundamental problem with regard to heat resistance. In addition, PET has a relatively high elastic modulus but low internal loss, so there is a problem that low-frequency reproduction is insufficient and peaks and dips are likely to occur in the acoustic frequency characteristics. When the stiffness is reduced, there is a problem that division resonance is likely to occur, and distortion during reproduction is likely to occur.

  ZV film has better heat resistance than PET diaphragm, but, like PET, the low frequency reproduction is insufficient and the peak and dip are likely to occur in the acoustic frequency characteristics and the film thickness. If the thickness is reduced and the stiffness is reduced, the split resonance is likely to occur, and the problem that distortion during reproduction is likely to occur cannot be solved.

  On the other hand, PPS film acoustic equipment diaphragms are superior to PET diaphragms in heat resistance and frequency characteristics, but they often have problems such as tearing and cracking when molded into speaker diaphragms. In terms of formability, yield and cost, it was not always satisfactory.

  Further, as an acoustic device diaphragm having both heat resistance and moldability, for example, a laminated film in which a resin layer containing an aromatic polyimide is laminated on both sides of a PPS film has been studied. There were problems such as poor adhesion and peeling of the resin layer from the PPS film during molding.

Therefore, the present invention has the following configuration in order to solve the above problems.
A silane coupling agent having at least one surface by the following chemical structure (1) of the PPS film 1. It is a laminated PPS film in which a primer layer made of a polyester resin containing 0 % by mass or more is laminated, and a resin layer containing an aromatic polyimide is laminated on the opposite side of the PPS surface of the primer layer.

X represents a mercapto group, and R ¹ and R ² may be the same or different and each represents an alkyl group having 1 to 4 carbon atoms. N represents an integer of 1 or more, and m represents an integer of 0 to 3.

  According to the present invention, surface treatment that imparts an easy-adhesion effect to at least one surface of the PPS film is performed, and the resin layer containing an aromatic polyimide is laminated on the treated surface, which is excellent in heat resistance, frequency characteristics, and moldability. A laminated PPS film can be provided.

It is a half sectional view showing one example of an audio equipment using the present invention.

The present invention is a silane coupling agent having at least one surface by the following chemical structure (1) of the PPS film 1. It is a laminated PPS film in which a primer layer made of a polyester resin containing 0 % by mass or more is laminated, and a resin layer containing an aromatic polyimide is laminated on the opposite side of the PPS surface of the primer layer.

Hereinafter, the laminated PPS film of the present invention will be described in more detail.
In the present invention, PPS refers to a polymer in which 80 mol% or more (preferably 90 mol% or more) of repeating units are composed of structural units represented by the following formula (I).

If this component is less than 80 mol%, the crystallinity, softening point and the like of the polymer are lowered, and the heat resistance, dimensional stability and mechanical properties of the resulting film are impaired. As long as it is less than 20 mol% (preferably less than 10 mol%) of the repeating unit, a unit containing a copolymerizable sulfide bond may be contained. The copolymerization method of the polymer may be random or block.

  In the present invention, the PPS resin composition refers to a resin composition containing 90% by mass or more of the PPS (preferably poly-p-phenylene sulfide). The remaining less than 10% by mass in the resin composition may be a polymer other than PPS and / or an additive such as a filler, a lubricant, a colorant, an ultraviolet absorber, an antistatic agent and an antioxidant.

Further, the melt viscosity of the PPS resin composition of the present invention is preferably in the range of 100 to 50000 poises, more preferably 500 to 12000 poises at a temperature of 300 ° C. and a shear rate of 200 sec ⁻¹ in terms of film forming property. The PPS film of the present invention is a biaxially stretched film obtained by melt-molding the above PPS resin composition.

  In the present invention, particles may be mixed into the PPS resin composition in order to change the surface roughness of the PPS film. Regardless of whether the particles are organic or inorganic, for example, minerals such as silica, alumina, calcium carbonate, magnesium oxide, titanium oxide, aluminum silicate, barium sulfate, metals, metal oxides, metal salts, What is necessary is just fine particles, such as a high melting point polymer and a crosslinked polymer. The mixing amount of particles and the average particle diameter may be appropriately changed according to the purpose.

The surface of the PPS film of the present invention preferably has an easy adhesion effect, and is preferably subjected to corona treatment. The amount of corona treatment is 600 to 12000 J / m ² (10 to 200 W · min / m ² ) or more, preferably 1,200 to 9000 J / m ² (20 to 180 W · min / m ² ) or more. When the amount of corona treatment is less than 600 J / m ² (10 W · min / m ² ), the adhesion effect due to corona treatment is insufficient, and then a laminated PPS film laminated with a primer layer and a resin layer is laminated during processing. There is a tendency that the resin layer etc. which peel are easy to peel. When the corona treatment amount is 12000 J / m ² (200 W · min / m ² ) or more, the adhesion effect due to the corona treatment reaches a peak, and 12000 J / m ² (200 W · min / m ² ) or less is sufficient.

  In the present invention, a primer layer is preferably laminated between the PPS film and the resin layer. Here, the primer layer is a layer having an effect of improving the adhesion between the PPS film and the resin layer. When the adhesiveness between the PPS film and the resin layer is high, inconveniences such as peeling of the resin layer are unlikely to occur in the processing step of processing the laminated PPS film.

  The method for laminating the primer layer is not particularly limited, and may be any method such as a method of providing by coextrusion with a PPS film, a method of applying a solution in which a primer layer forming component is dissolved in a PPS film and / or a resin layer, and drying. . The primer layer coating method is not particularly limited, and various known coating methods such as reverse coating, gravure coating, rod coating, bar coating, Mayer bar coating, die coating, and spray coating may be used. Can do.

  As a material for the primer layer, urethane resin, polyester resin, acrylic resin, and the like can be used, and polyester resin is preferable. The polyester resin may be a modified product or a copolymer. The primer layer preferably contains a cross-linking agent. Examples of the crosslinking agent include melamine compounds, oxazoline-based crosslinking agents, isocyanate compounds, aziridine compounds, epoxy resins, methylolized or alkylolized urea-based crosslinking agents, acrylamide-based crosslinking agents, polyamide-based resins, amide-epoxy compounds, and the like. Can be used.

  In the present invention, the adhesion between the PPS film and the resin layer is further improved by adding a silane coupling agent having the following chemical structure (1) to the primer layer.

The chemical structure (1) is as described above, X represents a mercapto group, R ¹ and R ² may be the same or different, and represent an alkyl group having 1 to 4 carbon atoms. N represents an integer of 1 or more, and m represents an integer of 0 to 3. The mercapto group is a functional group represented by (—SH), and the alkyl group is (C _n H _{2n + 1} ): n is a functional group represented by an integer of 1 or more. When a silane coupling agent that does not contain a mercapto group is added, there is a tendency that the resin layer and the like laminated during the processing of the laminated PPS film in which the primer layer and the resin layer are laminated are easily peeled off.

  The addition amount of the silane coupling agent of the present invention is preferably 1% by mass or more, more preferably 5% by mass or more, to the polymer primer. When the addition amount is 1% by mass or less, there is a tendency that a resin layer or the like laminated during processing is easily peeled off.

  The thickness of the high primer layer of the present invention is preferably 0.1 μm or more, more preferably 0.3 μm or more. When the thickness of the primer layer is less than 0.1 μm, the adhesion effect by the primer layer is reduced, and the laminated PPS film having the resin layer laminated thereon tends to peel off during the processing of the laminated PPS film.

  The polyimide used for the resin layer of the present invention preferably has an imidization ratio of polyamic acid of 50% or more. If the imidation rate is less than 50%, the heat-resistant function may not be sufficiently exhibited, which is not preferable. The imidation ratio is more preferably 75% or more, and further preferably 90% or more.

The imidation rate referred to here is the ratio of dehydration ring closure reaction between the amide group and the carboxyl group in the polyamic acid to form an imide group. Although it does not specifically limit as a method to measure this imidation rate, In this invention, the infrared absorption spectrum of a resin layer is measured by an ATR method using an infrared spectrophotometer, At that time, 1400cm < ^-1 > to 1300cm < ^- > ¹ is a value calculated using a method obtained from the strength of characteristic absorption of the imide group appearing in ¹ .

  Although the kind of polyimide used for the resin layer of the present invention is not particularly limited, from the viewpoint of heat resistance, as the polyamic acid, the structural unit represented by the following formula (II) and / or (III) has an entire structure. It is preferably 70 mol% or more in the unit, more preferably 90 mol% or more.

R in the formulas (II) and (III) is at least one group selected from the following formula (IV): wherein X and Y in the formula (IV) are O, CH ₂ , CO , SO ₂ , S, C (CH ₂ ) ₂ .

  When the portion exceeding 30 mol% of the total structural units of the polyamic acid is not the structural unit represented by the above formula (II) and / or (III), there is no effect of heat resistance and flame retardancy, If the thickness is not increased, the effects of heat resistance and flame retardancy may not be obtained, and there may be no advantage in productivity and cost.

  In addition, the polyamic acid having a structure other than the structural unit represented by the above formula (II) and / or (III) in an amount of more than 30 mol% increases the raw material cost when synthesizing the polyamic acid, and thus the sheet heat generation Problems such as increased body costs may occur. The polyamic acid in the present invention is more preferably a polyamic acid having 70 mol% or more of a structural unit represented by the following formula (V), particularly preferably 90 mol% of a structural unit represented by the following formula (V). It is a polyamic acid having the above.

  Solvents for these polyamic acid resins are not particularly limited, but N-methyl-2-pyrrolidone, N, N-dimethylformamide, N, N-dimethylacetamide, N, N, N ′, N′-tetramethylurea Amide solvents such as N, N-dimethylimidazolidinone and hexamethylphosformamide, and lactam solvents such as γ-butyrolactam are used.

  When the polyamic acid solution is applied and formed as the resin layer of the present invention, in the solution, a hydroxypyridine compound represented by the following formula (VI), an imidazole compound represented by the following formula (VI), It is preferable that at least one compound selected from m-hydroxybenzoic acid, p-hydroxyphenylacetic acid, and p-phenolsulfonic acid is contained in an amount of 1 mol% or more based on the repeating unit of the polyamic acid.

  In the formula, at least one of R 1, R 2, R 3, R 4 and R 5 represents a hydroxyl group, and the other represents any one of a hydrogen atom, an aliphatic group, an aromatic group, a cycloalkyl group, an aralkyl group and a formyl group, respectively. Show.

  In the formula, each of R1, R2, R3, and R4 represents a hydrogen atom, an aliphatic group, an aromatic group, a cycloalkyl group, an aralkyl group, or a formyl group. As R1, R2, R3 and R4, for example, an aliphatic group is preferably an alkyl group having 1 to 17 carbon atoms, a vinyl group, a hydroxyalkyl group or a cyanoalkyl group, and in the case of an aromatic group, a phenyl group is preferred. In the case of an aralkyl group, a benzyl group is preferred.

  The hydroxypyridine compound represented by the above formula (VI), the imidazole compound represented by the formula (VII), m-hydroxybenzoic acid, p-hydroxyphenylacetic acid, and p-phenolsulfonic acid include an amide acid component. Since at least one compound selected from these compounds is added due to the effect of promoting dehydration and cyclization, the imidization rate can be increased by a heat treatment at a lower temperature and in a shorter time than when not added. It is preferable because efficiency is improved.

  Specific examples of the hydroxypyridine compound of the formula (VI) include 2-hydroxypyridine, 3-hydroxypyridine, 4-hydroxypyridine, 2,6-dihydroxypyridine, 3-hydroxy-6-methylpyridine, 3-hydroxy- Examples include 2-methylpyridine.

  Specific examples of the imidazole compound of the formula (VII) include 1-methylimidazole, 1-ethylimidazole, 1-propylimidazole, 1-phenylimidazole, 1-benzylimidazole, 1-vinylimidazole, 1-hydroxyethylimidazole, 2-methylimidazole, 2-ethylimidazole, 2-propylimidazole, 2-isopropylimidazole, 2-butylimidazole, 2-undecylimidazole, 2-heptadecylimidazole, 2-phenylimidazole, 2-benzylimidazole, 4-methyl Imidazole, 4-phenylimidazole, 4-benzylimidazole, 1,2-dimethylimidazole, 1,4-dimethylimidazole, 1,5-dimethylimidazole, 1-ethyl-2-methylimidazo 1-vinyl-2-methylimidazole, 2,4-dimethylimidazole, 2-ethyl-4-methylimidazole, 2-phenyl-4-methylimidazole, 2-butyl-4-hydroxymethylimidazole, 2-butyl- 4-formylimidazole, 2,4-diphenylimidazole, 4,5-dimethylimidazole, 4,5-diphenylimidazole, 1-benzyl-2-methylimidazole, 1-benzyl-2-phenylimidazole, 1,2,5- Trimethylimidazole, 1,4,5-trimethylimidazole, 1-methyl-4,5-diphenylimidazole, 2-methyl-4,5-diphenylimidazole, 2,4,5-trimethylimidazole, 2,4,5-tri Phenylimidazole, 1-cyanoethyl-2-methyl Imidazole, 1-cyanoethyl-2-ethyl-4-methylimidazole, 1-cyanoethyl-2-undecyl imidazole, 1-cyanoethyl-2-phenylimidazole and the like.

  The amount of these compounds added is more preferably 10 mol% or more, and still more preferably 50 mol% or more, based on the repeating unit of the polyamic acid. When the addition amount is less than 1 mol% with respect to the repeating unit of the polyamic acid, it is difficult to obtain the effect of increasing the imidization rate at a low temperature in a short time. The upper limit of the amount added is not particularly limited, but is preferably 300 mol% or less with respect to the repeating unit of the polyamic acid. Even if it exceeds 300 mol%, the effect is not remarkably improved, and conversely, the use amount increases, which may be disadvantageous in terms of cost.

  The resin layer of the present invention may contain a resin or an organic compound other than the polyimide resin component by copolymerization or mixing. As resins and organic compounds other than polyimide resin components, for example, antioxidants, heat stabilizers, ultraviolet absorbers, organic particles, pigments, dyes, antistatic agents, various flame retardants, acrylic resins, polyester resins, urethane resins, Polyolefin resin, polycarbonate resin, alkyd resin, epoxy resin, urea resin, phenol resin, silicone resin, rubber resin, wax composition, melamine compound, oxazoline crosslinking agent, methylolated, alkylolized urea crosslinking agent, Acrylamide resins, polyamide resins, isocyanate compounds, aziridine compounds, various silane coupling agents, various titanate coupling agents, and the like can be used. In particular, non-halogen and non-phosphorus compounds are more preferable as environmentally friendly materials that do not generate toxic gases during a fire. Moreover, as these materials, an insulating material is more preferable.

  However, if the resin or organic compound other than the polyimide resin component is excessively contained, the heat resistance may be lowered. For this reason, the resin layer containing polyimide in the present invention is preferably a resin layer. The content of the polyamic acid resin having an imidization ratio of 50% or more in the resin layer is 70% by mass or more in the resin layer. More preferably, it is 80 mass% or more, More preferably, it is 90 mass% or more.

  On the other hand, various inorganic additives may be added to the resin layer of the present invention as long as the effects of the present invention are not inhibited. In particular, an insulating material is preferable. For example, silica, colloidal silica, alumina, alumina sol, kaolin, talc, mica, calcium carbonate, barium sulfate, zeolite, titanium oxide, aluminum hydroxide, antimony oxide, magnesium hydroxide, zinc borate, zinc stannate, zirconium flame retardant The addition of a molybdenum-based flame retardant is preferable because it improves slipperiness, scratch resistance, heat resistance, flame retardancy, and the like. The average particle diameter of the inorganic particles is preferably 0.005 μm to 5 μm, more preferably 0.05 to 1 μm. Moreover, 0.05-60 mass% is preferable with respect to the resin layer, as for the addition amount, More preferably, it is 0.1-40 mass%, More preferably, it is 0.5-20 mass%.

  In the present invention, the coating method of the polyamic acid solution is not particularly limited, and various known coating methods such as reverse coating method, gravure coating method, rod coating method, bar coating method, Mayer bar coating method, die coating method, spray coating, etc. The method etc. can be used.

  After application of the polyamic acid solution, the amide group and carboxyl group in the polyamic acid are dehydrated and closed by heat treatment to imidize. The heat treatment method is not particularly limited, but usually a method of dehydrating and cyclizing with hot air of 150 ° C. or higher or far infrared rays is preferably used. More preferably, it is 180 degreeC or more, More preferably, it is 200 degreeC or more. The heat treatment time is preferably 1 second to 120 seconds, more preferably 5 seconds to 60 seconds, and still more preferably 10 seconds to 30 seconds. If the temperature is lower than this, or if the heat treatment time is short, the imidization rate is lowered, which is not preferable. Further, if the heat treatment time is longer than this, the productivity is deteriorated, which is not preferable.

  In addition to the above methods, a film made of polyimide resin may be laminated on the PPS film and the resin layer may be laminated. However, it is difficult to obtain good adhesiveness, and the production efficiency may be deteriorated. .

  In the present invention, the ratio of the resin layer thickness to the total thickness of the laminated PPS film is preferably 0.25 to 15%. The ratio of the resin layer thickness is more preferably 0.5 to 5%, and still more preferably 0.5 to 2.5%. Here, the resin layer thickness is the thickness of the resin layer on one side. When the ratio of the resin layer thickness to the total thickness of the laminated PPS film is within such a range, the effect of heat resistance is sufficiently exhibited and the productivity is good. At this time, the thickness of the resin layer is preferably about 0.05 to 10 μm per side, more preferably 0.1 to 5 μm, and still more preferably about 0.1 to 2.5 μm. When the ratio of the resin layer thickness is large and / or the resin layer is thick, the adhesion between the PPS film provided with the primer layer and the resin layer may be lowered. Further, when the ratio of the thickness of the resin layer is small and / or when the thickness of the resin layer is small, a problem of tearing or breaking when the laminated PPS film is processed is likely to occur.

  The thickness of the laminated PPS film of the present invention can be determined as appropriate according to the acoustic device to be applied, but is preferably 3 μm to 250 μm, and more preferably 25 to 100 μm. When the thickness is 3 μm or less, a problem of tearing or breaking when forming the film is likely to occur, and the workability is deteriorated. On the other hand, when the thickness is 250 μm or more, the rigidity of the film is increased, so that the flexibility of the film is lost, and the frequency characteristics as the diaphragm are deteriorated.

  The elastic modulus of the laminated PPS film of the present invention is preferably 3.5 GPa or more and 8 GPa or less, and more preferably 4.0 GPa or more and 6 GPa or less in both the longitudinal direction and the width direction of the film. When the elastic modulus is within such a preferable range, sufficient frequency characteristics can be obtained when used as an acoustic device diaphragm, and the moldability is not deteriorated and the acoustic device diaphragm is not easily molded.

  The thermal shrinkage at 100 ° C. in the longitudinal direction of the laminated PPS film is preferably less than 1.0% and −0.5% or more, and more preferably 0% or more and less than 0.5%. When the heat shrinkage is within such a preferable range, the moldability and heat resistance as an acoustic device diaphragm are sufficient.

  The laminated PPS film of the present invention has a glass transition temperature of 150 ° C. or higher, preferably 200 ° C. or higher, preferably 350 ° C. or lower, more preferably 300 ° C. or lower. When the glass transition temperature is less than 150 ° C., the heat resistance of the acoustic device diaphragm composed of the film may be insufficient.

〔Evaluation method〕
The following measurements (1) to (5) were performed on the laminated PPS films prepared in each Example and Comparative Example.

(1) Film thickness A cross section of a laminated PPS film is cut out and the cross section is observed with a transmission electron microscope HU-12 manufactured by Hitachi, Ltd. The primer layer thickness (t1) on one side and the entire laminated PPS film The thickness (t2) of was measured.

(2) The moldable film is heated in a temperature atmosphere of 150 ° C. and molded and pressed with a mold heated to about 40 ° C., so that the acoustic device diaphragm 8 used in the speaker having the configuration shown in FIG. Make it. At this time, 100 speakers were produced, and the moldability was judged according to the following criteria.
○: Can be formed into a desired shape without any problem.
Δ: 1 to 3 wrinkles due to heat shrinkage strain.
X: Three or more wrinkles are generated due to heat shrinkage distortion or tearing during processing, and a diaphragm having a desired shape cannot be obtained.

(3) Dynamic elastic modulus Measured under the following conditions using a non-resonant forced stretching vibration type device DMS6100 manufactured by Seiko Instruments. The measurement direction is the longitudinal direction of the film. The measurement was carried out 10 times, and the average value of the measured values at 25 ° C. was obtained.
Frequency: 10 Hz Vibration displacement: 25 μm Initial load: 200 mN Temperature increase rate: 2 ° C./min Sample size: 35 mm (chuck interval) × 10 mm (width) Measurement atmosphere: in nitrogen gas flow Measurement chamber atmosphere: 23 ° C., 60% RH
(4) Glass transition temperature (Tg)
Specific heat was measured with the following equipment and conditions, and determined according to JIS K7121.
Apparatus: Temperature modulation DSC manufactured by TA Instrument Measurement temperature: 270-570K (RCS cooling method) Temperature calibration: Melting point of high purity indium and tin Temperature modulation amplitude: ± 1K Temperature modulation period: 60 seconds Temperature increase step: 5K Sample mass : 5 mg Sample container: Aluminum open container (22 mg) Reference container: Aluminum open container (18 mg)
The glass transition temperature was calculated by the following formula.
Glass transition temperature = (extrapolated glass transition start temperature + extrapolated glass transition end temperature) / 2
(5) Adhesiveness of resin layer 100 pieces of 1 mm ² crosscuts are put in the resin layer of the laminated PPS film, and cellophane tape manufactured by Nichiban Co., Ltd. is attached on the surface on which the crosscuts are put, and a rubber roller is used. After reciprocating 3 times with a load of 19.6 N, it was peeled in the direction of 90 degrees. Two-stage evaluation (◯: 100, x: 0 to 99) was performed according to the number of remaining resin layers. ○ is a pass.

[Example 1]
A PPS film having a thickness of 50 μm (Torelina (registered trademark) # 50 3000 manufactured by Toray Industries, Inc.) was used as a film substrate, and corona treatment was performed on both sides thereof. The corona discharge treatment machine uses a Kasuga Electric Co., Ltd. corona discharge treatment machine HFS400F, the aluminum electrode and the treater roll use a silicone-coated roll, the gap between the electrode and the roll is 2 mm, the line speed is about 30 m / min, the applied energy Processing was performed at a density of 100 W · min / m ² .

  Next, the following melamine compound 1 as a crosslinking agent is mixed with the following polyester resin 1 so as to have a solid content mass ratio of 85/15, and a mixed solvent of isopropyl alcohol and water (10/90 (mass) The composition diluted to have a solid content concentration of 3% by mass was used as a coating solution 1 for forming a primer layer.

・ Polyester resin 1:
・ 60 mol% of acid component terephthalic acid
Isophthalic acid 14 mol%
Trimellitic acid 20 mol%
Sebacic acid 6 mol%.

・ Diol component ethylene glycol 28mol%
Neopentyl glycol 38 mol%
1,4-butanediol 34 mol%.

  The polyester resin 1 (Tg: 20 ° C.) was made into an aqueous dispersion obtained by making it aqueous with ammonia water.

Melamine compound 1:
“Cymel (registered trademark)” 325 (imino group-type methylated melamine) manufactured by Cytec Co., which is a high solid type amino resin, was used as melamine compound 1.

  10% by mass of the following silane coupling agent Z-6062 manufactured by Toray Dow Corning Co., Ltd. is added to the coating solution 1 and applied to the entire surface of the PPS film with a gravure coater, dried in a heating zone at 105 ° C., and heat-treated at 220 ° C. And a primer layer of 0.3 μm was formed.

  Next, 4,4'-diaminodiphenyl ether weighed together with N-methyl-2-pyrrolidone was added to a stainless steel polymerization kettle and dissolved by stirring. Next, pyromellitic dianhydride was added to this solution so that the reaction temperature was 100 ° C. or less with respect to 100 mol of 4,4′-diaminodiphenyl ether. Thereafter, when the viscosity became constant, the polymerization was terminated to obtain a polyamic acid polymerization solution. To this, aluminum hydroxide (“Hagilite” H-42M, manufactured by Showa Denko KK) was added and dispersed in a solid mass ratio such that polyamic acid / aluminum hydroxide = 70/30. This solution is appropriately diluted with N-methyl-2-pyrrolidone so as to have a desired concentration according to the thickness of the resin layer, and 4-hydroxypyridine is added at 100 mol% with respect to the repeating unit of polyamic acid before coating. This was added to obtain a polyamic acid solution. This polyamic acid was a mixture of both two structural units in the following formula (VIII).

The polyamic acid is applied to the entire surface of the primer layer of the PPS film on which the primer layer is laminated with a gravure coater, dried at 130 ° C., and heat-treated at 200 ° C. to form a resin layer having a total thickness of 51 μm. An 8 μm laminated PPS film was obtained.

[Example 2]
A laminated PPS film was obtained in the same manner as in Example 1 except that one side of the film substrate was subjected to corona treatment, a primer layer was laminated on the corona treatment side, and a resin layer was laminated on the primer layer side.

Example 3
Using a PPS film having a thickness of 2.5 μm (Torelina (registered trademark) 1X00 manufactured by Toray Industries, Inc.) as the film substrate, corona treatment was performed on both sides thereof, and a primer layer was laminated on both sides by 0.1 μm, A laminated PPS film was obtained in the same manner as in Example 1 except that a resin layer was laminated on both sides by 0.3 μm.

Example 4
A PPS film (Torelina (registered trademark) 5000 manufactured by Toray Industries, Inc.) having a thickness of 175 μm was used as a film base, and corona treatment was performed on both sides thereof, and a primer layer was laminated on both sides by 0.3 μm. A laminated PPS film was obtained in the same manner as in Example 1 except that the resin layer was laminated to 2.5 μm.

[Comparative Example 1]
A laminated PET film was used in the same manner as in Example 1 except that a 50 μm thick PET film (Lumirror (registered trademark) # 50 S10 manufactured by Toray Industries, Inc.) was used in place of the 50 μm thick PPS film as the film substrate. Obtained.

[Comparative Example 2]
A laminated polypropylene film as in Example 1 except that a polypropylene film having a thickness of 50 μm (Torephane (registered trademark) # 50 BO manufactured by Toray Industries, Inc.) was used instead of the PPS film having a thickness of 50 μm as the film substrate. Got.

[Comparative Example 3]
A laminated PPS film was obtained in the same manner as in Example 1 except that the silane coupling agent was not added to the coating solution 1 constituting the primer layer.

[Comparative Example 4]
A laminated PPS film was obtained in the same manner as in Example 1 except that 0.5% by mass of the silane coupling agent Z-6062 manufactured by Toray Dow Corning Co., Ltd. was added to the coating solution 1 constituting the primer layer.

[Comparative Example 5]
A laminated PPS film was obtained in the same manner as in Example 1 except that the primer layer was not laminated on the PPS film.

[Comparative Example 6]
A laminated PPS film was obtained in the same manner as in Example 1 except that 10% by mass of a silane coupling agent Z-6020 manufactured by Toray Dow Corning Co., Ltd. containing an amino group was added to the coating solution 1 constituting the primer layer.

[Comparative Example 7]
A laminated PPS film was obtained in the same manner as in Example 1 except that 10% by mass of Toray Dow Corning silane coupling agent Z-6040 containing epoxy group was added to the coating liquid 1 constituting the primer layer.

[Comparative Example 8]
A laminated PPS film was obtained in the same manner as in Example 1 except that the coating liquid 1 constituting the primer layer was changed to SU3802 manufactured by San Yulec Co., which is a urethane resin.

[Comparative Example 9]
A laminated PPS film was obtained in the same manner as in Example 1 except that the coating liquid 1 constituting the primer layer was an epoxy resin except for NBP-800 manufactured by Sanyu Rec.

  Table 1 shows the characteristic evaluation results of Examples 1 to 4 and Comparative Examples 1 to 9. Although Examples 1-4 were favorable in all the items, Comparative Examples 1-9 had a bad point in any item.

  The present invention relates to a laminated polyphenylene sulfide film excellent in heat resistance, workability, and frequency characteristics, and various acoustic devices using the film, that is, a film for an acoustic device diaphragm or an acoustic device diaphragm constituting a speaker.

DESCRIPTION OF SYMBOLS 1 Magnetic circuit 2 Magnet 3 Plate 4 Yoke 5 Voice coil 6 Frame 7 Gasket 8 Sound equipment diaphragm 9 Magnetic gap

Claims (5)

A silane coupling agent having at least one surface by the following chemical structure (1) of the polyphenylene sulfide film 1. A primer layer made of a polyester resin containing 0 % by mass or more is laminated,
A laminated polyphenylene sulfide film in which a resin layer containing an aromatic polyimide is laminated on the surface opposite to the polyphenylene sulfide surface of the primer layer.

X represents a mercapto group, and R ¹ and R ² may be the same or different and each represents an alkyl group having 1 to 4 carbon atoms. N represents an integer of 1 or more, and m represents an integer of 0 to 3. 1. Silane coupling agent having the above chemical structure (1) formula on both sides of the polyphenylene sulfide film . The laminated polyphenylene sulfide film according to claim 1, wherein a primer layer made of a polyester resin containing 0 % by mass or more is laminated.   The laminated polyphenylene sulfide film according to claim 1 or 2, wherein the laminated polyphenylene sulfide film has a thickness of 3 µm to 250 µm, and the primer layer has a thickness of 0.1 µm or more. The laminated polyphenylene sulfide film according to any one of claims 1 to 3, wherein the polyphenylene sulfide film is subjected to corona treatment, and the treatment amount is 600 J / m ² (10 W · min / m ² ) or more.   The film for acoustic equipment diaphragms using the laminated polyphenylene sulfide film according to any one of claims 1 to 4.

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