JP2016163948A - Laminate and manufacturing method therefor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a laminate excellent in adhesiveness, moisture heat resistance and heat resistance and a manufacturing method therefor.SOLUTION: There is provided a laminate having a polyphenylene sulfide layer on both sides of a polyester layer and having strength retention rate after exposing the laminate to a 125°C 100% RH environment for 48 hours of 40% or more, elongation retention rate after exposing the laminate to a 180°C environment for 200 hours of 40% or more and the number of massage resistance by a massage test of 25 or more.SELECTED DRAWING: None

Description

  The present invention relates to a laminate and a method for producing the same, and is suitably used as electric insulation of a motor.

  As insulation materials for drive motors of electric and hybrid vehicles, and motors for compressors (for commercial use, home use, and on-vehicle air conditioners), polyester films with an excellent balance of properties, heat resistance, chemical resistance, etc. A polyphenylenelene sulfide film with improved properties or a laminate obtained by laminating these has been used.

  In recent years, in addition to the progress of miniaturization and higher output of motors, the operating temperature of compressor motors such as air conditioners has been increased by changing the refrigerant, and ATF (automatic transmission) oil has been used for automobile motors. Due to the widespread use of direct motor cooling, insulation films used in motors are required to have improved durability in high-temperature and high-humidity environments, as well as coolant and oil that directly touch the film. . At the same time, there is a high demand for reduction in manufacturing cost as products become widespread, and there is a demand for an insulator that is inexpensive and has excellent durability, and various studies have been made.

  For example, a laminate in which a polyphenylene sulfide film having excellent durability is laminated on a relatively inexpensive polyester film has been studied. In Patent Document 1, a polyphenylene sulfide film is laminated on both sides of a polyethylene terephthalate film via an adhesive. Patent Document 2 discloses a laminate in which a polyester film and a polyphenylene sulfide film are laminated by coextrusion. Patent Document 3 and Patent Document 4 disclose a laminate in which a surface-treated polyester film and a polyphenylene sulfide film are laminated without an adhesive.

JP-A-10-86306 JP 62-252123 A JP 2013-223985 A International Publication No. 2014/199844

  However, in the laminate using the adhesive of Patent Document 1, the adhesive layer is melted in a high-temperature refrigerant environment, and the adhesive strength at the interlayer interface is lowered due to a decrease in the durability of the adhesive and the heat resistance of the laminate. The decline in sex becomes a problem. As an example of such an environment, a case where a laminate is used as an insulator for a compressor coil of an air conditioner where refrigerant and oil coexist is raised, and the melted adhesive clogs inside the compressor and starts up There are problems such as causing defects. Moreover, the laminated body by the coextrusion method of patent document 2 has the problem that delamination generate | occur | produces at the time of processing of a laminated body, since the adhesiveness of each layer which comprises a laminated body is weak.

  The laminate of Patent Document 3 is a laminate subjected to heat treatment after joining, and the laminate of Patent Document 4 is a laminate obtained by laminating at a high temperature at the time of joining. Therefore, polyester is used in a high temperature and high humidity environment. There was a problem that the deterioration of the layer progressed and the heat and humidity resistance decreased.

  An object of the present invention is to provide a laminate excellent in adhesiveness, moist heat resistance and heat resistance, and a method for producing the same, in view of the problems of the prior art. More specifically, it is suitably used as electric insulation for a motor even in a harsh environment of high temperature and high humidity or in an environment where refrigerant and oil coexist.

The present invention uses the following means in order to solve this problem.
(1). A laminate having a polyphenylene sulfide layer on both sides of a polyester layer, wherein the laminate has a strength retention of 40% or more after being exposed to an environment of 125 ° C. and 100% RH for 48 hours, and the laminate is an environment of 180 ° C. A laminate having an elongation retention rate of 40% or more after exposure to 200 hours and a fir resistance of 25 or more.
(2). (1) The micro endothermic peak temperature (Tmeta) (° C.) obtained by differential operation calorimetry (DSC) of the laminate is 190 ° C. or higher and lower than 230 ° C., and the tensile strength of the laminate is 160 MPa or higher. Laminated body.
(3). The thickness of the polyester layer is 38 μm or more and 350 μm or less, the thickness per one side of the polyphenylene sulfide layer is 9 μm or more and 25 μm or less, the thickness of the polyester layer (a) and the total thickness (b) of the polyphenylene sulfide layer The laminate according to (1) or (2), wherein the ratio (a) / (b) is 1 or more and 30 or less.
(4). The laminate according to any one of (1) to (3), wherein the polyester layer and the polyphenylene sulfide layer are provided via an adhesive layer.
(5). The laminated body in any one of (1)-(4) whose thickness of the said contact bonding layer is 20 nm or more and 500 nm or less.
(6). A polyphenylene sulfide film having an adhesive layer with a thickness of 20 nm to 500 nm on both sides of the polyester film, and a plasma-treated polyphenylene sulfide film on the surface adjacent to the adhesive layer is laminated by 1.0 × Fm (N / m (1) to joining at a linear pressure of 10 N / cm or more and 300 N / cm or less with a pair of pressure rolls of 180 ° C. or more and 215 ° C. or less under a tension of (width) to 3.0 × Fm (N / m width). (5) The manufacturing method of the laminated body in any one of.
(7). The manufacturing method of the laminated body as described in (6) whose terminal carboxyl group amount of the polyester film before the said lamination | stacking is 25 equivalent / t or less, and whose intrinsic viscosity (IV) is 0.65 or more.
(8). The manufacturing method of the laminated body as described in (6) or (7) whose surface roughness (SRa) of the joint surface of the polyphenylene sulfide film before the said lamination is 25 nm or less.

  According to the present invention, it is possible to obtain a laminate satisfying adhesiveness, heat-and-moisture resistance, and heat resistance, and it can be suitably used in an environment where refrigerant and oil coexist, which is a severe environment of high temperature and high humidity. .

The laminate of the present invention is a laminate having polyphenylene sulfide layers on both sides of a polyester layer. The polyester layer used in the present invention is a layer mainly composed of a polyethylene terephthalate resin having an ester bond having an ethylene terephthalate structure as a main bond chain. The resin constituting the polyester layer preferably contains ethylene terephthalate constituents in an amount of 80 mol% or more in terms of quality, economy and the like, but in the range not impairing the effects of the present invention, for example, ethylene- Even if components such as 2,6-naphthalate, butylene terephthalate, ethylene-α, β-bis (2-chlorophenoxy) ethane-4,4′-dicarboxylate are copolymerized within a range of 20 mol% or less Good. The polyester layer has a good balance between properties and manufacturing costs, but it has difficulty in heat and moisture resistance, oil resistance and refrigerant resistance, and the usage environment may be limited. By having a polyphenylene sulfide layer having extremely excellent refrigerant resistance characteristics, it becomes possible to dramatically improve the performance.
The polyphenylene sulfide layer used in the laminate of the present invention is, for example, a film composed mainly of a resin containing 85 mol% or more of a paraphenylene sulfide unit represented by the following chemical formula 1, The content is preferably 90 mol% or more, and more preferably 97 mol% or more, from the viewpoint of heat resistance, refrigerant / oil resistance, and the like. As a constituent component other than paraphenylene sulfide, a constitution containing a phenylene sulfide component is preferable. In order to introduce a chain, for example, by using 1,2,4-trichlorobenzene, a trifunctional component is introduced.

  In the resin constituting the polyester layer or polyphenylene sulfide layer of the present invention, various additives such as antioxidants, heat stabilizers, weathering stabilizers, ultraviolet absorbers, organic lubricants, pigments, dyes, organic or Inorganic fine particles, fillers, antistatic agents, nucleating agents, crosslinking agents, and the like may be added to such an extent that the properties are not deteriorated.

  The polyester layer or polyphenylene sulfide layer in the present invention is a biaxially oriented film, and has the main characteristics necessary for the function of the film, such as improved mechanical strength, improved thermal stability, improved chemical resistance, and improved electrical properties. Preferred because it is expressed. The term “biaxial orientation” as used herein refers to a pattern showing a biaxial orientation pattern by wide-angle X-ray diffraction. A biaxially oriented polyester film is generally obtained by stretching an unstretched polyester sheet about 2.5 to 5.0 times in the sheet longitudinal direction and width direction, respectively, and then performing heat treatment to complete crystal orientation. be able to. The stretching in the longitudinal direction and the width direction may be a so-called sequential biaxial stretching method that is sequentially performed individually or a simultaneous biaxial stretching method that is performed simultaneously.

  The laminate of the present invention needs to have a strength retention of 40% or more after being exposed to 125 ° C. and 100% RH for 48 hours, and preferably 50% or more. When the strength retention is 40% or more, hydrolysis of the polyester layer is suppressed, and thus the heat resistance as a whole of the laminate is good. For example, it can be preferably used for a motor insulating material for a compressor of an air conditioner. If it is less than 40%, hydrolysis of the polyester layer of the laminate progresses and the heat-and-moisture resistance deteriorates. Therefore, when used as the insulating material, the insulation properties of the laminate as a whole are reduced, leading to electrical leakage and failure.

  The laminate of the present invention needs to have an elongation retention rate of 40% or more after being exposed to an environment of 180 ° C. for 200 hours, preferably 50% or more. When the elongation retention is 40% or more, the laminate has good heat resistance, deterioration under a high temperature environment is suppressed, and the heat resistance of the entire laminate can be maintained. If it is less than 40%, the heat resistance as a laminate is poor, and thermal degradation as a laminate cannot be suppressed.

  In the laminate of the present invention, it is necessary that the number of rub resistances by the rub test of the laminate is 25 or more, and preferably 30 or more. When the number of anti-frictions is 25 times or more, the laminate is excellent in adhesion, and even when the laminate of the present invention is subjected to processing steps such as punching, bending, and insertion into a motor, which will be described later, the adhesion between the layers is exhibited. Can be maintained. Further, when used as a motor insulating material for a compressor of an air conditioner, there is an advantage that the laminate is not broken when bent and inserted into the motor, and the workability is stabilized. If the number of anti-frictions is less than 25, the adhesive of the laminate is weak when bent or inserted into a motor, cracking occurs, or cracks as a laminate cannot be confirmed from the surface in the processing process. Micro-cleavage cracks occur in the interlayer of polyester and inside of the polyester layer. Under high temperature and high humidity environment, moisture is easily immersed and adsorbed on the cracked part, and the heat and humidity resistance of the laminate deteriorates. is there.

  It is very important that the laminate of the present invention satisfies all of adhesiveness, moist heat resistance, and heat resistance. By satisfying these characteristics, it becomes a laminate in which the adhesiveness, moist heat resistance, and heat resistance characteristics are not deteriorated even in an environment where refrigerant and oil that are in a severe environment of high temperature and high humidity coexist.

  In the laminate of the present invention, the minute endothermic peak temperature (Tmeta) (° C.) obtained by differential scanning calorimetry (DSC) of the laminate is 190 ° C. or more and less than 230 ° C., and the tensile strength of the laminate is 160 MPa or more. Preferably there is. More preferably, Tmeta is 200 ° C. or higher and lower than 225 ° C., and the tensile strength is 170 MPa or higher. When the Tmeta value is 190 ° C. or higher and lower than 230 ° C. and the tensile strength is 160 MPa or higher, the adhesiveness between the polyester layer and the polyphenylene sulfide layer is increased, so that the processability of the laminate is improved. When the Tmeta value is less than 230 ° C., it is possible to suppress a decrease in the orientation of the polyester layer due to heat at the time of joining, and this makes it easy to maintain the wet heat resistance of the entire laminate. In the present invention, the Tmeta value is an index indicating a thermal history at the time of joining a polyester layer and a polyphenylene sulfide layer, which will be described later, or a thermal history of the polyester film layer itself. If the molecular orientation of the film cannot be maintained at the time of joining the polyester layer and the polyphenylene sulfide layer, the tensile strength decreases and the degree of freedom of molecular motion increases, which is considered to accelerate the hydrolysis rate of the polyester layer. is there.

  In the configuration of the laminate of the present invention, the thickness of the polyester layer in the laminate is 38 μm or more and 350 μm or less, the thickness per one side of the polyphenylene sulfide layer is 9 μm or more and 25 μm or less, the thickness (a) of the polyester layer and the polyphenylene sulfide film The thickness ratio (a) / (b) of the total thickness (b) of the layer is preferably 1 or more and 30 or less. When the thickness of the polyester layer is 38 μm or more and 350 μm or less, the rigidity of the laminate is not lowered and good processability can be obtained, and the polyester layer is not cleaved by the inner layer during processing. Moreover, when the thickness per one side of the polyphenylene sulfide layer is 9 μm or more and 25 μm or less, it functions as a protective film for the polyester layer, and it becomes easy to maintain the moisture and heat resistance of the entire laminate. Therefore, good adhesiveness can be obtained while maintaining heat and humidity resistance in a refrigerant / oil environment. Further, when the thickness ratio (a) / (b) is 1 or more and 30 or less, the heat resistance of the entire laminate is good, the heat resistance against moisture and oil environment can be maintained, and the polyphenylene sulfide in the laminate The manufacturing cost can be suppressed from the viewpoint of the proportion of the layer.

  In the laminate of the present invention, the polyester layer and the polyphenylene sulfide layer are preferably laminated via an adhesive layer. In joining a polyester layer and a polyphenylene sulfide layer via an adhesive layer, it has been extremely difficult to align the adhesion between the polyester layer and the polyphenylene sulfide layer, and the moisture and heat resistance and heat resistance of the laminate. That is, when laminating at high temperature and high linear pressure to improve the adhesion, the molecular orientation is lowered and the heat and humidity resistance is deteriorated. On the other hand, when laminating at a low temperature and a low linear pressure in order to maintain the molecular orientation, the adhesiveness is lowered. In the present invention, it is possible to obtain a laminate having excellent adhesiveness between the layers of the laminate and wet heat resistance while having an adhesive layer by using the production conditions described later together, and having excellent heat resistance.

  In the laminate of the present invention, the coating liquid used for the adhesive layer is not particularly limited. For example, polyester resins such as polyethylene terephthalate and polyethylene naphthalate, cellulose resins such as triacetyl cellulose, polymethyl (meth) acrylate, and the like. Acrylic resin, styrene resin such as polystyrene and acrylonitrile / styrene copolymer, polycarbonate resin, polyethylene, polypropylene, ethylene / propylene copolymer, olefin resin such as norbornene and other olefinic resins, vinyl chloride Resin, nylon, aromatic polyamide resin, imide resin, polyphenylene sulfide resin, polyether sulfone resin, vinylidene chloride resin, vinyl alcohol resin, vinyl butyral resin, arylene DOO resins, polyoxymethylene-based resins, epoxy-based resin or a mixed resin thereof. In particular, in order to obtain adhesiveness with a fir resistance of 25 or more in the fir test, use any one of the above-mentioned resins, polyester resin, acrylic resin, urethane resin, or use a mixed resin thereof. Makes it easier to achieve.

  In the laminate of the present invention, the thickness of the adhesive layer on one side is preferably 20 nm or more and 500 nm or less, and more preferably 50 nm or more and 300 nm or less. If the thickness of the adhesive layer on one side of the laminate is 20 nm or more, the adhesion between the layers is excellent, and if it is 500 nm or less, even if the adhesive is thermally deteriorated in a high temperature environment, the influence on the entire laminate is not affected. It is preferable because the heat resistance of the laminate can be kept small, and the adhesive does not ooze out under the usage environment of the refrigerant and does not affect other members such as a compressor.

  Preferred examples of the method for obtaining the laminate of the present invention are shown below, but the present invention is not limited thereto.

  In the present invention, an adhesive layer having a thickness of 20 nm or more and 500 nm or less is provided on both surfaces of the polyester film, a polyphenylene sulfide film subjected to plasma treatment is laminated on the surface adjacent to the adhesive layer, and bonded under heat and pressure conditions. It is preferable.

  In the present invention, it is preferable to have adhesive layers on both sides of the polyester film in order to improve the adhesion between the polyester film and the polyphenylene sulfide film. There are various methods for providing an adhesive layer on both sides of a polyester film. In the present invention, a so-called in-line coating method is preferably used in which a coating solution is applied in a film forming process, dried, stretched, and then heat treated. be able to. By using the in-line coating method, compared to offline processing, for example, the coating film can be made thin and uniform, the adhesion with the polyester film is improved, and both ends in the width direction are gripped by the clip during heat treatment Therefore, there is an advantage that wrinkles are not easily generated on the film. The method of applying to the polyester film is not particularly limited, and for example, a reverse coating method, a gravure coating method, a rod coating method, a bar coating method, a metalling wire bar coating method, a die coating method, a spray coating method and the like can be used. In order to reduce the appearance unevenness of the adhesive layer, a gravure coating method and a metalling wire bar coating method are preferable, and a metaling wire bar coating method is particularly preferable.

In the present invention, it is preferable to laminate a polyphenylene sulfide film subjected to plasma treatment on the surface adjacent to the adhesive layer in order to achieve both heat and moisture resistance and adhesiveness. Examples of plasma treatment include plasma treatment that combines various conditions of normal pressure, low pressure, high temperature, and low temperature. In the present invention, in particular, in order to suppress a decrease in the degree of orientation of the polyester film, heat fusion processing is performed at a relatively low temperature. A low temperature plasma treatment under various gases that can be produced is particularly preferred. The low temperature plasma treatment here is a treatment performed by exposing the film surface to a discharge that is started and maintained by applying a DC or AC high voltage between the electrodes. The type and the like can be selected as appropriate and are not particularly limited, but the processing strength is 50 W · min / m ^{2 to} 5000 W within a pressure range of 0.1 Pa to 1330 Pa, more preferably 1 Pa to 266 Pa. A preferred method is to perform glow discharge treatment in a range of min / m ² or less. The processing atmosphere is generally argon (Ar), helium (He), nitrogen (N ₂ ), oxygen (O ₂ ), air, carbon dioxide (CO ₂ ), water vapor (H ₂ O), or the like. In the case of an atmosphere containing water vapor, the treatment efficiency is particularly good. Further, the water vapor may be diluted with another gas such as Ar, He, N ₂ , O ₂ , air, or CO ₂ .

  In the production method of the present invention, the polyester film is preferably produced by, for example, the steps shown below. After the polyester raw material is melted at 270 to 320 ° C. and formed into a film using a slit-shaped die, it is wound around a casting drum having a surface temperature of 20 to 70 ° C. to be cooled and solidified to obtain an unstretched film. Subsequently, the film is stretched 2.5 to 3.5 times in the longitudinal direction at 60 to 120 ° C. to obtain a uniaxially stretched film. Thereafter, the uniaxially stretched film was introduced into the tenter, preheated at 100 to 140 ° C., then stretched 2.5 to 4.0 times in the width direction, and heat treated at 215 to 235 ° C. to obtain a biaxially oriented polyester film. . It is possible to increase the strength by further stretching in the vertical or horizontal direction, or both in the vertical and horizontal directions before the heat treatment. In addition, it is not necessarily limited to the manufacturing method shown here. It is also possible to manufacture by the simultaneous biaxial stretching method, for example, without adopting the above two-step stretching method.

  Next, although a polyphenylene sulfide film is described, for example, it is preferable to produce it by the following steps. After the polyphenylene sulfide raw material is melted at 290 to 360 ° C. and formed into a film shape using a slit-shaped die, it is wound around a casting drum having a surface temperature of 20 to 70 ° C. to be cooled and solidified to obtain an unstretched film. Subsequently, the film is stretched 3.0 to 5.0 times in the longitudinal direction at 90 to 120 ° C. to obtain a uniaxially stretched film. Thereafter, the uniaxially stretched film is introduced into a tenter, preheated at 90 to 120 ° C., stretched 2.0 to 4.0 times in the width direction, and heat treated at 200 to 280 ° C. to obtain a biaxially oriented polyphenylene sulfide film. It was. In addition, it is not necessarily limited to the manufacturing method shown here.

  In the production method of the present invention, the adhesive layer provided on both sides of the polyester film and the polyphenylene sulfide film are laminated so that the surface subjected to the plasma surface treatment is adjacent, preferably 180 ° C. or higher and 215 ° C. or lower, More preferably at a temperature of 190 ° C. to 210 ° C., a pair of pressure rolls, preferably a linear pressure of 10 N / cm to 300 N / cm, more preferably 30 N / cm to 270 N / cm The method of directly joining while running is preferable. When the temperature is 180 ° C. or higher, the Tmeta value tends to be high and the bonding force between the films tends to be improved. When the temperature is 215 ° C. or lower, the decrease in the molecular orientation of the polyester film is suppressed and the heat and humidity resistance can be maintained. Tend. In addition, when the linear pressure is 10 N / cm or more, the bonding force between the films tends to be improved. When the linear pressure is 300 N / cm or less, the appearance of the polyester film is whitened or the line pressure is uneven in the width direction. Deterioration can be suppressed. The pair of pressurizing rolls can press the respective films, which are laminated from the upper surface by fixing the position of the lower rotating roll, with a rotating roll that can be driven to the upper film surface, and can be pressed while being conveyed. In these driving operations, pressure may be applied from both the upper stage and the lower stage, or may be applied from only one side. Examples of the roll type include metal, SUS, and a mode in which the roll surface has a rubber elastic body. This is because the hardness of the rubber elastic body used on the roll surface is preferably 50 degrees or more and 80 degrees or less, and within this range, the strength retention of the laminate can be easily maintained. However, if the pressurization conditions are increased, depending on the properties of the rubber elastic body, pressurization is performed while applying heat, so use a combination of metal rolls that do not cause deformation, breakage, cracks, etc. due to the influence of heat and pressure. It is more preferable. This is because these defects may affect the adhesion of the laminate. As the pair of pressure rolls in the present invention, a combination of a metal roll and a rubber roll or a combination of metal rolls is preferably used. When using a combination of a metal roll and a rubber roll, in order not to cause these defects, the linear pressure is preferably 10 N / cm or more and 50 N / cm or less, more preferably 30 N / cm or more and 50 N / cm or less, and a combination of metal rolls In this case, damage such as the above-described rubber elastic body does not occur, and therefore, it may be appropriately adjusted within the above range. In the present invention, the take-up tension T of the laminate at the time of joining with a pair of pressure rolls is 1.0 × Fm (N / mm width) or more and 3.0 × Fm (N / mm width) or less. It is preferable. Fm is the maximum value Fme (N / mm width) of the contraction stress in the longitudinal direction of the polyester film constituting the laminate when heated from 30 ° C. to the bonding temperature, and when heated from 30 ° C. to the bonding temperature. Is the sum of the maximum value Fms (N / mm width) of the contraction stress in the longitudinal direction of the polyphenylene sulfide film constituting the laminate. In order to prevent the polyester film from being lowered in orientation during thermal bonding and to prevent flatness and wrinkle generation in the laminate, it is possible to control the take-up tension in the above range in addition to the temperature and linear pressure during bonding. It becomes important. When the take-up tension T is less than 1.0 × Fm (N / mm width), it is difficult to maintain the orientation of the film, and there is a tendency that the tensile strength is reduced and the heat and humidity resistance is deteriorated. When exceeding × Fm (N / mm width), the film is likely to wrinkle at the time of bonding, the appearance is deteriorated, the bonding force between the films at the wrinkled portion is reduced, and the speed control in the laminating process is possible. May become unstable. In the present invention, the bonding process using the pair of pressure rolls may be performed only once, or may be performed a plurality of times within a range that does not impair the characteristics of the present invention. The laminated body once joined is unwound so that the contact surface with the pressure roll is opposite to the first time, and the method of performing the joining treatment again increases the joining force and the pressure roll contact surface at the time of joining. It is preferable to prevent the occurrence of a difference in characteristics due to.

  In the laminate of the present invention, the polyester film and the polyphenylene sulfide film are firmly bonded while maintaining the orientation of the polyester film as described above, and the polyester film is a polyphenylene sulfide film excellent in moisture and heat resistance, refrigerant resistance and oil resistance characteristics. However, it is preferable to improve the moisture and heat resistance of the polyester film itself in order to improve the moisture and heat resistance of the entire laminate. From the viewpoint of improving the heat and moisture resistance of the polyester film, the laminate of the present invention is a laminate formed by laminating a polyester film having an intrinsic viscosity (IV) of 0.65 or more and a terminal carboxyl group content of 25 equivalents / t or less. It is preferable that it is a body. The polyester resin is a crystalline resin. Furthermore, in a polyester film obtained by biaxially stretching such a crystalline polyester, a portion where the polyester is crystallized by orientation (hereinafter referred to as an oriented crystallized portion) and a non-crystallized resin. There is a crystal part. Here, the amorphous part is considered to be in a state where the density is lower than that of the crystal part and the oriented crystal part and the average intermolecular distance is large. When the polyester film is exposed to a moist heat atmosphere, moisture (water vapor) enters the inside through the molecules of the amorphous part having a low density, plasticizes the amorphous part, and increases the mobility of the molecule. Further, moisture (water vapor) promotes hydrolysis of an amorphous part having increased molecular mobility using a proton at the carboxyl group terminal of the polyester as a reaction catalyst. Hydrolyzed polyester with a low molecular weight further increases molecular mobility, and progresses in hydrolysis and crystallization. As a result of this being repeated, embrittlement of the film progresses, and finally, even a slight impact results in a state of breaking. Since the hydrolysis reaction proceeds using the proton at the carboxyl group terminal of the polyester as a reaction catalyst, it is considered that the moisture and heat resistance improves as the amount of the terminal carboxyl group in the polyester resin constituting the polyester film decreases. The amount of terminal carboxyl groups is preferably 20 equivalents / t or less, more preferably 13 equivalents / t or less, and still more preferably 10 equivalents / t or less. The lower limit value is not particularly limited, but it is difficult to make it substantially 1 equivalent / t or less due to the characteristics of the polymer. In the present invention, when the intrinsic viscosity (IV) of the polyester film constituting the laminate is less than 0.65, the molecular mobility in a heat-and-moisture resistant environment is easily increased because the polyester molecular chain is shortened, or the terminal portion. Increase in heat resistance tends to deteriorate the moisture and heat resistance. Intrinsic viscosity (IV) is preferable when solid-phase polymerization is performed at the time of producing a polyester resin because the amount of the terminal carboxyl group is reduced and the intrinsic viscosity (IV) can be easily adjusted to the above range. In addition, in the melted state when the polyester resin is melt-formed, hydrolysis and thermal decomposition with residual water proceed. Therefore, the intrinsic viscosity (IV) of the polyester resin used as the film material is the intrinsic viscosity (IV) of the polyester film. ) Is preferably higher than the target value. However, in order to increase the intrinsic viscosity (IV) of the polyester resin, it is necessary to lengthen the solid phase polymerization time during the production of the polyester resin or increase the amount of the catalyst added, which leads to deterioration of the color and characteristics of the polyester resin. There is a case. Therefore, even if the intrinsic viscosity (IV) of the polyester resin is higher than the target value of the intrinsic viscosity (IV) of the polyester film, the difference is preferably smaller, and it is less than the target value of the intrinsic viscosity (IV) of the polyester film. It is preferable to make it 0.05 to 0.15 higher. Before the polyester resin is melt-extruded into a film, the moisture content in the polyester resin is reduced to 50 ppm or less in advance by heating the polyester resin under reduced pressure, or when the film is melt-extruded into a film. The temperature of the polyester resin is set to the melting point (Tm) of the polyester resin + 30 ° C. or less, and the melting time of the resin from the extruder tip to the die is set to less than 5 minutes, and further to less than 3 minutes. It is possible to suppress the hydrolysis and thermal decomposition during the film to reduce the decrease in intrinsic viscosity (IV), and to stably obtain a polyester film having good heat and moisture resistance. The intrinsic viscosity (IV) of the polyester film is more preferably 0.68 or more. From the viewpoint of hydrolysis resistance and thermal decomposition, the upper limit is not particularly limited. However, if it exceeds 1.0, it is difficult to melt and extrude when forming a film, so that the film forming property deteriorates substantially. It becomes difficult to obtain a film, and is preferably 0.8 or less.

  In the laminate of the present invention, it is preferable to bond a polyphenylene sulfide film having a surface roughness (SRa) on the bonding surface side of 25 nm or less in order to improve the bonding force between the films. The polyester film and polyphenylene sulfide film are bonded by applying heat and pressure, but the bonding mechanism is that in the initial state, the adhesive on the polyester film and the molecules on the surface of the polyphenylene sulfide layer are close to each other. It is considered that a strong bonding force is finally expressed by bonding by molecules due to Coulomb force, and then a transition between molecules that are close to each other over time shifts from an intermolecular force and a Coulomb force to a chemical bond. The smoothness of the film surface of the bonding surface makes it easier for the molecules that form the surface of the film to approach each other, improving intermolecular force and Coulomb force, and making it easier to shift to chemical bonding. Is estimated to improve.

[Measurement method of physical properties]
Hereinafter, the configuration and effects of the present invention will be described more specifically with reference to examples. In addition, this invention is not limited to the following Example. Prior to describing each example, a method for measuring various physical properties will be described.

(1) Tensile strength A sample for measurement having a width of 10 mm and a length of 250 mm was taken from the laminate so that the longitudinal direction of the laminate was the length direction. Using a constant-speed tension type tensile testing machine, pulling in the sample length direction at an original length (distance between chucks) of 100 mm and a pulling speed of 200 mm / min, the tensile load value when the film breaks is determined by breaking the laminate before testing the sample. A value (MPa) divided by the area was calculated. The measurement was performed 5 times for each sample, and the average value of 5 times was taken as the tensile strength.
In addition, when a longitudinal direction cannot be specified, the ultrasonic conduction velocity in a laminated body surface is measured by Nomura Shoji Co., Ltd. SONIC SHEEET TESTER SST-4000, and the direction with the fastest speed is considered as a longitudinal direction.

(2) Strength retention (moisture and heat resistance)
A sample for measurement having a width of 10 mm and a length of 250 mm was taken from the laminate so that the longitudinal direction of the laminate was the length direction. The cut out sample was processed for a specified time (48 hours) in an environment of a temperature of 125 ° C. and a humidity of 100 RH% using an advanced accelerated life test apparatus EHS-221 (manufactured by Espec). The strength of the film before and after the treatment was measured using a constant-speed tension type tensile tester under the conditions of an original length (distance between chucks) of 100 mm and a tensile speed of 200 mm / min. In addition, about the tensile strength, it was set as the average value measured by N = 5, respectively. Regarding the obtained film strength, the value obtained by dividing the tensile strength after the treatment by the tensile strength before the treatment was evaluated as the strength retention in the evaluation of moisture and heat resistance according to the following criteria. In addition, S is very good, A is good, B is a practical range, S, A, and B are acceptable, and C is unacceptable.
S: Strength retention is 70% or more A: Strength retention is 50% or more and less than 70% B: Strength retention is 40% or more and less than 50% C: Strength retention is less than 40%

(3) A sample for measurement having a width of 10 mm and a length of 250 mm was taken from the tensile stretch laminate so that the longitudinal direction of the laminate was the length direction. Using a constant speed tension type tensile tester, the film was pulled in the sample length direction at an original length (distance between chucks) of 100 mm and a pulling speed of 200 mm / min, and the elongation when the film broke was determined. Direct measurement was performed 5 times for each material, and the average value of 5 times was defined as tensile elongation.
In addition, when a longitudinal direction cannot be specified, the ultrasonic conduction velocity in a laminated body surface is measured by Nomura Shoji Co., Ltd. SONIC SHEEET TESTER SST-4000, and the direction with the fastest speed is considered as a longitudinal direction.

(4) Elongation retention (heat resistance)
A sample for measurement having a width of 10 mm and a length of 250 mm was taken from the laminate so that the longitudinal direction of the laminate was the length direction. The cut out sample was subjected to treatment for a specified time (200 hours) in a constant temperature dryer GPHH-200 (manufactured by Tabai) in an environment at a temperature of 180 ° C. The elongation of the film before and after the treatment was measured using a constant-speed tension type tensile tester under conditions of an original length (distance between chucks) of 100 mm and a tensile speed of 200 mm / min. In addition, about tensile elongation, it was set as the average value measured by N = 5, respectively. About the obtained film elongation, the value which remove | divided the tensile elongation after a process by the tensile elongation before a process was evaluated on the basis of the following as elongation retention in heat resistance evaluation. In addition, S is very good, A is good, B is a practical range, S, A, and B are acceptable, and C is unacceptable.
S: The elongation retention is 70% or more A: The elongation retention is 50% or more and less than 70% B: The elongation retention is 40% or more and less than 50% C: The elongation retention is less than 40%.

(5) The number of times of resistance by the fir test A sample for measurement having a width of 10 mm and a length of 200 mm was taken from the laminate so that the longitudinal direction of the laminate was the length direction. Using a Scott Scratch Resistance Tester (manufactured by Toyo Seiki Co., Ltd.), the cut sample was subjected to the number of times of resistance (cleaving within the polyester layer or under the conditions of 30 mm original length (chuck distance), 50 mm stroke, 4.5 kg load) The number of times until peeling between the polyester layer and the polyphenylene sulfide layer occurred was measured. In addition, about the number of times of anti-foaming, it was set as the average value measured by N = 5, respectively, and evaluated on the basis of the following. A is good, B is in the practical range, A and B are acceptable, and C is unacceptable.
A: The number of times of rub resistance is 30 times or more B: The number of times of rub resistance is 25 times or more and less than 30 C: The number of times of rub resistance is less than 25 times.

(6) Minute endothermic peak temperature (Tmeta)
The film and laminated body before lamination were measured with a differential scanning calorimeter (DS Instruments Q100 manufactured by TA Instruments) at a temperature rising rate of 20 ° C./min in the range of 30 ° C. to 300 ° C. The minute endothermic peak temperature before the PET crystal melting peak in the differential scanning calorimetry chart obtained by this measurement was defined as each Tmeta (° C.). Tmeta appears as a history of the heat treatment temperature for the polyester layer.

(7) Film thickness of each layer in the laminate
The cross section of the laminate cut out with a microtome was observed with an optical microscope (100 times) or a scanning electron microscope (1000 times), a photograph was taken, and the overall thickness of the laminate and the thickness of each layer were determined from the dimensions of the cross-sectional photograph. Measured. The same measurement was carried out at any five locations of the laminate, and the average value was the total thickness of the laminate and the thickness of each layer.

(8) Shrinkage stress of film The polyester film and the polyphenylene sulfide film before lamination were each measured using TMA (TMA / SS6100, manufactured by SII Nanotechnology), and the shrinkage stress in the film longitudinal direction was measured under the following conditions.
Sample size 2mm wide x 10mm long (1mm wide x 10mm long if stress is over)
Measurement range 20 ℃ ~ 250 ℃
Temperature rising rate 5 ° C / min Measurement atmosphere N ₂ (100 mL / min)
From the obtained stress chart, the maximum value between 30 ° C. and the joining temperature was read and divided by the sample width to obtain the maximum value of the shrinkage stress of the sample. For each bonding condition, the maximum shrinkage stress value of the polyester film is Fme (N / m width), the maximum shrinkage stress value of the polyphenylene sulfide film is Fms (N / m width), and the total (for example, PPS) In the case of a three-layer structure of / PET / PPS, Fme + 2 × Fms) was defined as Fm (N / m width).

(9) The amount of terminal carboxyl group was measured by the following method according to the method of Malice (reference MJ Malice, F. Huizinga. Anal. Chim. Acta, 22 363 (1960)).
2 g of polyester resin or polyester film before lamination is dissolved in 50 mL of o-cresol / chloroform (weight ratio 7/3) at a temperature of 80 ° C., and titrated with 0.05 N KOH / methanol solution to measure the terminal carboxyl group concentration. And expressed as equivalents / polyester 1t. In addition, the indicator at the time of titration used phenol red, and the place where it changed from yellowish green to light red was set as the end point of titration.

(10) Intrinsic viscosity of polyester film (IV)
A polyester resin or a polyester film was dissolved in 100 mL of orthochlorophenol (solution concentration C = 1.2 g / mL), and the viscosity of the solution at 25 ° C. was measured using an Ostwald viscometer. Similarly, the viscosity of the solvent was measured. Using the obtained solution viscosity and solvent viscosity, [η] was calculated by the following formula (C), and the obtained value was used as the intrinsic viscosity (IV).
ηsp / C = [η] + K [η] ² · C Formula (C)
(Where ηsp = (solution viscosity / solvent viscosity) −1, K is the Huggins constant (assuming 0.343)).
(11) Film surface roughness (SRa)
The surface of the polyphenylene sulfide film before lamination was measured by a stylus method under the following conditions using a three-dimensional surface roughness meter (manufactured by Kosaka Laboratory, ET4000AK). The surface roughness (SRa) is the difference between the height of the roughness curved surface and the height of the center surface of the roughness curved surface, and represents the average value of the absolute values.
Needle diameter 2μmR
Needle pressure 10mg
Measurement length 500μm
Vertical magnification 20000 times CUT OFF 250μm
Measuring speed 100μm / s
Measurement interval 5μm
Number of records 80 lines Hysteresis width ± 6.25nm
Reference area 0.1 mm ² .

(12) Buckling resistance Using a slot cell insertion machine manufactured by Nittoku Engineering, a laminated body having a width of 40 mm and a length of 165 mm is processed into a slot liner shape and inserted into a 48-slot motor stator. Subsequently, using a coil winding machine manufactured by Nittoku Engineering Co., Ltd., the coil is wound by the distributed winding method so that the space factor, which is the ratio of the coil sectional area to the slot sectional area, becomes 65%. -Using a wedge insertion machine, the coil is inserted into a motor stator, a laminated body having a width of 10 mm and a length of 160 mm is processed into a wedge shape, and inserted into the motor stator. At this time, the slot liner and wedge in which buckling occurred were regarded as defective products, and the defective product occurrence rate was evaluated according to the following criteria. It should be noted that the number of processing is 5 as motors and 240 as slot liners and wedges. A is good, B is in the practical range, A and B are acceptable, and C is unacceptable.
A: The defect rate is 1% or less B: The defect rate exceeds 1% and is 5% or less C: The defect rate exceeds 5%.

[Reference Example 1] Preparation of polyester resin pellet 1 100 parts by mass of dimethyl terephthalate and 60 parts by mass of ethylene glycol were mixed at a temperature of 260 ° C under a nitrogen atmosphere. Thereafter, the temperature was lowered to 225 ° C., 0.08 parts by mass of calcium acetate and 0.029 parts by mass of antimony trioxide were added, and then 16.9 parts by mass of ethylene glycol was gradually added over 2 hours while stirring. Was distilled to complete the transesterification reaction. Subsequently, 0.16 mass part of lithium acetate and 0.11 mass part of trimethyl phosphate were added, and it moved to the polymerization reaction tank. Next, the polymerization reaction was carried out under a reduced pressure of 285 ° C. and a pressure of 13 Pa to obtain a polyester having an intrinsic viscosity of 0.54 and a terminal carboxyl group number of 18 equivalents / t. The polyester is cut into rectangular parallelepipeds of 2 mm × 4 mm × 4 mm on each side, further dried and crystallized at 160 ° C. for 6 hours, and then subjected to solid phase polymerization at 220 ° C. for 20 hours under a reduced pressure of 65 Pa. Polyester resin pellets 1 having an intrinsic viscosity (IV) of 0.80, a carboxyl group terminal group amount of 10 equivalent / t, and a melting point of 260 ° C. were obtained.

[Reference Example 2] Preparation of polyester resin pellet 2 100 parts by mass of dimethyl terephthalate and 38.4 parts by mass of ethylene glycol were mixed at a temperature of 260 ° C under a nitrogen atmosphere. Thereafter, the temperature was lowered to 225 ° C., 0.068 parts by mass of manganese acetate tetrahydrate and 0.029 parts by mass of antimony trioxide were added, and then 16.9 parts by mass of ethylene glycol was gradually added over 2 hours while stirring. The methanol was distilled off to complete the transesterification reaction. Subsequently, 0.015 mass part of phosphoric acid was added, and it moved to the polymerization reaction tank. Next, the polymerization reaction was carried out under a reduced pressure of 285 ° C. and a pressure of 13 Pa to obtain a polyester having an intrinsic viscosity of 0.55 and a terminal carboxyl group amount of 16.5 equivalents / t. The polyester is cut into rectangular parallelepipeds of 2 mm × 4 mm × 4 mm on each side, further dried and crystallized at 160 ° C. for 6 hours, and then subjected to solid phase polymerization at 220 ° C. for 20 hours under a reduced pressure of 65 Pa. Polyester resin pellet 2 having an intrinsic viscosity (IV) of 0.82, a terminal carboxyl group amount of 9.5 equivalent / t, and a melting point of 260 ° C. was obtained.

[Reference Example 3] Preparation of polyester resin pellet 3 The intrinsic viscosity (IV) was adjusted to 0.65 by adjusting the polymerization reaction time, and the intrinsic viscosity was determined in the same manner as in claim 1 except that solid phase polymerization was not performed. (IV) Polyester resin pellets 3 having 0.65, a terminal carboxyl group amount of 22 equivalent / t, and a melting point of 259 ° C. were obtained.

[Reference Example 4] Preparation of polyester resin pellet 4 In the same manner as in Reference Example 1 except that the solid phase polymerization time was adjusted to 12 hours, intrinsic viscosity (IV) 0.72, terminal carboxyl group amount 13 equivalent / t. A polyester resin pellet 4 having a melting point of 260 ° C. was obtained.

Reference Example 5 Preparation of Silicon Dioxide Particle-Containing Polyester Resin Pellets 5 To polyester resin 1 prepared in Reference Example 2, 5% by weight of silicon dioxide having an average particle size of 3.0 μm is added and uniformly dispersed and blended at 280 ° C. After being extruded in a gut shape by a 30 mmφ twin-screw extruder at a temperature of 1, the cut was obtained to obtain an intrinsic viscosity (IV) of 0.77, a terminal carboxyl group amount of 12 equivalents / t, and a silicon dioxide-containing polyester resin pellet 5.

[Reference Example 6] Preparation of polyphenylene sulfide resin pellets 1 An autoclave was charged with 100 mol parts of sodium sulfide 9 hydrate, 45 mol parts of sodium acetate and 259 mol parts of N-methyl-2-pyrrolidone (NMP) and stirred. While gradually raising the temperature to 220 ° C., the contained water was removed by distillation. To the system after the dehydration, 101 mol parts of p-dichlorobenzene as a main component monomer and 0.2 mol parts of 1,2,4-trichlorobenzene as an accessory component together with 52 mol parts of NMP were added, and 170 ° C. After pressurizing and filling nitrogen at 3 kg / cm ² at a temperature of 1, the temperature was raised and polymerization was carried out at 260 ° C. for 4 hours. After completion of the polymerization, the polymer was cooled, the polymer was precipitated in distilled water, and a small polymer was collected with a wire mesh having a 150 mesh opening. The small polymer thus obtained was washed 5 times with distilled water at 90 ° C. and then dried under reduced pressure at a temperature of 120 ° C. to obtain a PPS bulk powder having a melting point of 280 ° C. The resulting PPS bulk powder was extruded in a gut shape with a 30 mmφ twin screw extruder at a temperature of 320 ° C. and then cut to obtain polyphenylene sulfide resin pellets 1.

[Reference Example 7] Preparation of calcium carbonate particle-containing polyphenylene sulfide resin pellet 2 To polyphenylene sulfide resin 1 prepared in Reference Example 4, 7% by weight of calcium carbonate powder having an average particle size of 1.0 μm was added and uniformly dispersed and blended. Then, it was extruded in a gut shape at a temperature of 320 ° C. with a 30 mmφ twin-screw extruder and then cut to obtain polyphenylene sulfide resin pellets 2 containing calcium carbonate particles.

[Example 1]
(1) Production of Biaxially Oriented Polyester Film The polyester resin pellet 1 obtained in Reference Example 1 was dried in a vacuum at 160 ° C. for 6 hours, then supplied to an extruder and melt-extruded at 295 ° C. After filtering with stainless steel fiber sintered and compressed through a filter with an average opening of 60 μm, it is extruded into a sheet form from a T-shaped die, wound around a mirror casting drum having a surface temperature of 20 ° C. using an electrostatic application casting method, and cooled and solidified. I was damned. At this time, the melting time of the resin from the front end of the extruder to the die is 2 minutes, and further, the air velocity is 20 m from a slit nozzle with a gap of 2 mm, in which 12 stages of cold air having a temperature of 10 ° C. are installed in the longitudinal direction from the opposite surface of the casting drum The film was sprayed at / s and cooled from both sides. This unstretched film is preheated to 80 ° C. with a preheating roll, and is then stretched 3.3 times in the longitudinal direction using the difference in peripheral speed between the rolls while heating to 90 ° C. using a radiation heater, and subsequently used as a cooling roll. And cooled to 25 ° C. to obtain a uniaxially oriented film. Both surfaces of the film were subjected to corona discharge treatment in air, and the surface tension of the film was 55 mN / m. The following coating liquid was apply | coated using the metaling wire bar which is a coating liquid application | coating apparatus which has a measurement bar on both surfaces of the said uniaxially stretched film. The metering wire bar has a diameter of 13 mm and a wire diameter of 0.1 mm (# 4), the upstream cover tip position is 4 mm above the center of rotation of the measuring bar, and the downstream cover tip position is rotated by the measuring bar. The lower side of the center was 1 mm, and the tip of the upstream cover was installed so that it was 5 mm higher than the tip of the downstream cover. The gap between the metering wire bar and the upstream cover is adjusted to 1.5 mm, and the gap between the metering wire bar and the downstream cover is adjusted to 0.7 mm using a gap gauge. Furthermore, it was supplied from the lower part on the upstream side.
<Coating liquid>
An aqueous solution containing the following components when the polyester resin solid content is 100 parts by weight, and having a concentration in terms of polyester resin solid content of 5.0%. Moreover, the wetting tension of the resin solid obtained by heating and drying this coating liquid was 42 mN / m, and the refractive index was 1.58.
Polyester resin: 100 parts by weight melamine-based crosslinking agent (“Nikarak” MW12LF, manufactured by Sanwa Chemical Co., Ltd.): 50 parts by weight (in terms of solid content)
Colloidal silica having a particle size of 140 nm: 1.5 parts by weight Fluorosurfactant (“Plus Coat” RY2 manufactured by Kyoyo Chemical Co., Ltd.): 1.5 parts by weight (in terms of solid content)
Both ends in the width direction of the uniaxially oriented film coated with the aqueous coating liquid on both sides are held by clips and preheated in an oven at an ambient temperature of 110 ° C., and continuously 3.7 in the width direction in a 120 ° C. stretching zone. The film was stretched twice. The obtained biaxially oriented film was subsequently heat-treated for 10 seconds in a heating zone at 215 ° C., and then cooled to 215 ° C. to 160 ° C., and the interval between clips facing in the width direction was shortened to achieve 5.0% relaxation treatment. gave. Then, after cooling to 100 ° C. in the oven, the film holding the both ends in the film width direction is separated, the film is taken out from the oven, the both ends in the width direction are cut and removed, and taken up after being conveyed by the conveying roll. A biaxially oriented polyester film 1 having a thickness of 188 μm and having an adhesive layer having a thickness of 100 nm was obtained. The properties of the obtained film are shown in Table 2.

(2) Production of Biaxially Oriented Polyphenylene Sulfide Film The polyphenylene sulfide resin pellet 1 obtained in Reference Example 6 and the calcium carbonate particle-containing polyphenylene sulfide resin pellet 2 obtained in Reference Example 7 were mixed at a weight ratio of 90:10. After drying for 4 hours at a temperature of 180 ° C. under a reduced pressure of 3 mmHg using a rotary vacuum dryer, the mixture was supplied to an extruder and melt-extruded at 310 ° C. After filtering with stainless steel fiber sintered and compressed through a filter with an average opening of 14 μm, it is extruded into a sheet from a T-shaped die, wound on a mirror casting drum with a surface temperature of 25 ° C. using an electrostatic application casting method, and cooled and solidified. I was damned. This unstretched film is preheated to 92 ° C. with a preheating roll, and then stretched 3.7 times in the longitudinal direction using the difference in peripheral speed between the rolls while heating to 105 ° C. using a radiation heater, and subsequently used as a cooling roll. And cooled to 25 ° C. to obtain a uniaxially oriented film. Next, both ends in the width direction of the uniaxially oriented film were held with clips and preheated in an oven at an ambient temperature of 100 ° C., and continuously stretched 3.4 times in the width direction in a stretching zone at 100 ° C. The obtained biaxially oriented film was subsequently heat treated for 6 seconds in a 260 ° C heating zone, and then 5.0% relaxation treatment was performed by reducing the distance between the clips facing in the width direction while cooling from 260 ° C to 200 ° C. gave. After cooling to 115 ° C in the oven, the film is taken out of the oven by separating the clips holding the both ends in the film width direction, the both ends in the width direction are cut and removed, and the wound thickness after being transported by the transport roll A biaxially oriented polyphenylene sulfide film 1 having a thickness of 16 μm was obtained. Table 3 shows the characteristics of the obtained polyphenylene sulfide film.

(3) Low-temperature plasma treatment of polyphenylene sulfide film Low-temperature plasma treatment was performed on one surface of the biaxially oriented polyphenylene sulfide film 1 obtained as described above under the following method and conditions. This is an internal electrode type low temperature plasma processing apparatus, Ar is used as a processing gas, the pressure is 40 Pa, the processing speed is 1 m / min, and the processing strength (value calculated by applied voltage / (processing speed × electrode width)) is 500 W · min. / M ² .

(4) Bonding of polyester film and polyphenylene sulfide film The plasma-treated surface of the surface plasma-treated biaxially oriented polyphenylene sulfide film is adjacent to the adhesive layer on both sides of the biaxially oriented polyester film having adhesive layers on both sides obtained above. In this way, the film is rolled up and overlapped, and a roll laminator is used for bonding under the conditions of a linear pressure of 40 N / cm and a take-up tension of 800 N / m width with a combination of a pair of metal rolls with a roll surface temperature of 200 ° C. and a rubber roll. did. The obtained laminate was unwound and once again joined by a roll laminator with a pair of rolls having a roll surface temperature of 200 ° C. under conditions of a linear pressure of 40 N / cm width and a take-up tension of 800 N / m width. Thereafter, an aging treatment was performed at 40 ° C. for 72 hours to obtain a three-layer laminate having a polyphenylene sulfide film / adhesive layer / polyester film / adhesive layer / polyphenylene sulfide film structure and a thickness of 243 μm. The properties of the obtained laminate are shown in Table 5-1. The polyester film and the polyphenylene sulfide film are firmly bonded, and the number of times of rub-off in the rub test is 29 times, and the strength retention rate, which is an indicator of moist heat resistance, is 77%, and the heat resistance is high. It was a film having an excellent elongation retention ratio of 55%, which is an index of the properties, and excellent adhesion, moist heat resistance, and heat resistance.

[Examples 2-28, Comparative Examples 1-8]
The production conditions and characteristics of the polyester film are shown in Table 2, the production conditions and characteristics of the polyphenylene sulfide film are shown in Table 3, and the joining conditions of the polyester film and the polyphenylene sulfide film are as shown in Tables 4-1 and 4-2. According to Example 1, a laminate of polyphenylene sulfide film / polyester film / polyphenylene sulfide film was obtained. The properties of the obtained laminate are shown in Tables 5-1 and 5-2.

[Comparative Example 9]
The polyester resin pellet 1 obtained in Reference Example 1 was dried in a vacuum at 160 ° C. for 6 hours, then supplied to the extruder A and melt extruded at 295 ° C. Further, the polyphenylene sulfide resin pellet 1 obtained in Reference Example 6 and the calcium carbonate particle-containing polyphenylene sulfide resin pellet 2 obtained in Reference Example 7 were mixed at a weight ratio of 90:10, and 3 mmHg using a rotary vacuum dryer. After drying for 4 hours at a temperature of 180 ° C. under reduced pressure, the mixture was supplied to the extruder B and melt-extruded at 310 ° C. The polyester resin extruded from the extruder A was filtered with a filter having an average opening of 60 μm obtained by sintering and compressing stainless steel fibers, and the polyphenylene sulfide resin extruded from the extruder B was sintered and compressed stainless steel fibers. After filtration through a filter with an average opening of 60 μm, the feed block was laminated in three layers in the thickness direction so that it would be a polyphenylene sulfide layer / polyester layer / polyphenylene sulfide layer in the thickness direction, and then a T-shape The sheet was extruded from the die into a sheet and wound around a mirror casting drum having a surface temperature of 20 ° C. by using an electrostatic application casting method to be cooled and solidified. At this time, cold air having a temperature of 10 ° C. was blown onto the film at a wind speed of 20 m / s from a slit nozzle having a gap of 2 mm provided in the longitudinal direction from the opposite surface of the casting drum, and cooling was performed from both sides. The melting time of the resin from the front end of the extruder on the polyester resin side to the die was 2 minutes. The obtained unstretched film is preheated to 90 ° C. with a preheating roll, then stretched 3.3 times in the longitudinal direction using the difference in peripheral speed between the rolls while being heated to 103 ° C. using a radiation heater, and then cooled. It cooled to 25 degreeC with the roll, and was set as the uniaxially oriented film. Next, both ends in the width direction of the uniaxially oriented film were held with clips and preheated in an oven at an ambient temperature of 110 ° C., and continuously stretched 3.4 times in the width direction in a 120 ° C. stretching zone. The resulting biaxially oriented film was subsequently heat-treated for 10 seconds in a heating zone at 225 ° C., and then cooled to 215 ° C. to 160 ° C., and the interval between the clips facing in the width direction was reduced to achieve 5.0% relaxation treatment. gave. Then, after cooling to 100 ° C in the oven, the film holding the both ends in the film width direction is separated and the film is taken out from the oven, and the both ends in the width direction are cut and removed. A laminate having a thickness of 246 μm (polyphenylene sulfide layer / polyester layer / polyphenylene sulfide layer = 18 μm / 210 μm / 18 μm) was obtained. The characteristics of the obtained laminate are shown in Table 5-2.

[Comparative Example 10]
Using a polyester film obtained by excluding the coating liquid coating step from the production conditions for the biaxially oriented polyester film described in Example 1, polyphenylene sulfide was used according to Example 1 except that the bonding conditions were as shown in Table 4-2. A laminate of film / polyester film / polyphenylene sulfide film was obtained. The characteristics of the obtained laminate are shown in Table 5-2.

[Summary of results]
Buckling resistance (workability) and strength retention when the Tmeta of the laminate is 190 ° C or higher and lower than 230 ° C, the tensile strength is 160 MPa or higher, and the polyester film and the polyphenylene sulfide film are bonded via an adhesive layer. (Moisture and heat resistance) and elongation retention (heat resistance) can be aligned. As a method for producing a laminate that can be combined with buckling resistance (workability), heat and humidity resistance, and heat resistance, both surfaces of a biaxially oriented polyester film having an adhesive layer on both sides are subjected to surface plasma treatment biaxial orientation. The plasma-treated surface of the polyphenylene sulfide film is laminated so as to be adjacent to the adhesive layer, and the linear pressure is 10 N / cm to 300 N / cm with a pair of pressure rolls at a temperature of 180 ° C. to 215 ° C. while the film is running. Bonding is performed under the following pressure, and a method is adopted in which the take-up tension T of the laminated body at the time of bonding is 1.0 × Fm (N / m width) or more and 3.0 × Fm (N / m width) or less. By doing so, it became possible to achieve stably.

  Further, when a polyester film having an intrinsic viscosity of 0.65 or more and a terminal carboxyl group amount of less than 25 equivalent / t is used, the strength retention rate (moisture resistance) is compared with that in other cases (Examples 15 and 16). Heat resistance) and elongation retention (heat resistance) were good. In addition to the bonding state at the interface between the polyester film and the polyphenylene sulfide film, the composition of the resin composing the polyester film and the molecular orientation state in the film are thought to affect the heat and moisture resistance and heat resistance after lamination. Sometimes, maintaining the resin properties and orientation of the polyester film while joining the interface between the polyester film and the polyphenylene sulfide film with sufficient strength balances buckling resistance (workability), moisture and heat resistance, and heat resistance. It is considered necessary for this. In addition, as a method for increasing the interfacial bonding force between the polyester film and the polyphenylene sulfide film, in Examples 20 to 22 in which the surface roughness of the bonding surface was reduced, the bonding force (number of times of resistance to fringing) increased, and the bonding temperature and linear pressure were increased. Even when downed, good characteristics were maintained. It is presumed that the surfaces became easy to approach each other at the molecular level by making the surfaces smooth.

  On the other hand, in Comparative Example 1 in which the temperature during bonding is less than 180 ° C., the amount of heat at the time of lamination is insufficient, and the interfacial bonding force between the polyester film and the polyphenylene sulfide film is reduced. It was inferior in property (workability). Comparative Examples 2 and 3 in which the temperature at the time of bonding was higher than 215 ° C. and the Tmeta value exceeded 230 ° C. and the tensile strength was less than 160 MPa were inferior in strength retention (moisture heat resistance) and elongation retention (heat resistance). . About the comparative example 4 whose thickness of an contact bonding layer is 1000 nm, the elongation retention (heat resistance) was inferior, and also the malfunction which an adhesive agent elutes in a refrigerant | coolant environment was confirmed. In Comparative Example 5 in which the tension is too low, it is difficult to maintain the orientation of the film, the tensile strength is lowered and the heat and humidity resistance is deteriorated, and in Comparative Example 6 in which the linear pressure is too low, the bonding force at the interface is weak (resistance to resistance). The number of fir trees was low) and the buckling resistance (workability) was poor. In Comparative Example 7 where the polyphenylene sulfide film is thick as a thickness structure and Comparative Example 8 where the polyester film is thick, the bonding force at the interface is inferior, and the buckling resistance (workability) is lowered. In Comparative Example 9 in which the lamination was performed by the coextrusion method, the bonding force between the polyester layer and the polyphenylene sulfide layer was insufficient, and the layers were peeled off, so the number of times of fringing was low and the buckling resistance was insufficient. At the same time, the strength retention (wet heat resistance) was also insufficient. Because the bonding strength at the interface between the polyester layer and the polyphenylene sulfide layer is insufficient, water can easily enter the interface between the polyester layer and the polyphenylene sulfide layer in the hydrolysis resistance test, and the strength retention rate of the laminate has decreased. Presumed. In Comparative Example 10 in which the polyester film and the polyphenylene sulfide film were directly bonded without using an adhesive layer, the bonding temperature was raised in order to maintain the adhesion between the layers. As a result, the orientation of the polyester film was lowered and sufficient heat and humidity resistance was obtained. It was not obtained.

According to the laminate and the method for producing the same according to the present invention, a low-cost and highly durable laminate that does not deteriorate in characteristics even in a harsh environment such as high temperature and high humidity or in an environment where refrigerant, oil, etc. coexist is obtained. Therefore, it can be suitably used as various insulating materials such as a motor and a base. In particular, it is suitable for an insulating material used for a compressor motor such as an air conditioner or a drive motor such as an automobile, which is used in a high-temperature and high-humidity environment or an environment exposed to refrigerant or oil during use.

Claims (8)

A laminate having a polyphenylene sulfide layer on both sides of a polyester layer, wherein the laminate has a strength retention of 40% or more after being exposed to an environment of 125 ° C. and 100% RH for 48 hours, and the laminate is an environment of 180 ° C. A laminate having an elongation retention rate of 40% or more after exposure to 200 hours and a fir resistance of 25 or more. 2. The endothermic peak temperature (Tmeta) (° C.) obtained by differential operation calorimetry (DSC) of the laminate is 190 ° C. or higher and lower than 230 ° C., and the tensile strength of the laminate is 160 MPa or higher. Laminated body. The thickness of the polyester layer is 38 μm or more and 350 μm or less, the thickness per one side of the polyphenylene sulfide layer is 9 μm or more and 25 μm or less, the thickness of the polyester layer (a) and the total thickness (b) of the polyphenylene sulfide layer The laminate according to claim 1 or 2, wherein the ratio (a) / (b) is 1 or more and 30 or less. The laminate according to any one of claims 1 to 3, wherein the polyester layer and the polyphenylene sulfide layer are formed via an adhesive layer. The laminate according to any one of claims 1 to 4, wherein the adhesive layer has a thickness of 20 nm to 500 nm. An adhesive layer having a thickness of 20 nm to 500 nm is provided on both sides of the polyester film, and a plasma-treated polyphenylene sulfide film is laminated on the surface adjacent to the adhesive layer, and the laminated polyester film and polyphenylene sulfide film are run. With a tension of 1.0 × Fm (N / m width) or more and 3.0 × Fm (N / m width) or less, a linear pressure of 10 N / cm or more with a pair of pressure rolls of 180 ° C. or more and 215 ° C. or less The manufacturing method of the laminated body in any one of Claims 1-5 joined at 300 N / cm or less. The method for producing a laminate according to claim 6, wherein the amount of terminal carboxyl groups of the polyester film before lamination is 25 equivalent / t or less and the intrinsic viscosity (IV) is 0.65 or more. The method for producing a laminate according to claim 6 or 7, wherein the surface roughness (SRa) of the joining surface of the polyphenylene sulfide film before lamination is 25 nm or less.