laminated body

Abstract

The present invention aims to provide a laminate having excellent adhesion, processability, oil resistance, heat resistance, and resistance to moist heat. The solution is a laminate comprising, in order, a film A, a film B, and a film C, with adhesive layers interposed therebetween, wherein the adhesive layer between film A and film B is defined as adhesive layer AB, and the adhesive layer between film B and film C is defined as adhesive layer BC. In the laminate, the maximum thermal shrinkage of film B at 150°C for 30 minutes is 0.1% or more and 3.0% or less, and the Martens hardness of adhesive layers AB and BC is 1.0 N / mm. 2 Above and 4.0N / mm 2 When the laminate was immersed in automatic transmission fluid and heat treated at 150°C for 10 hours, the bonding area ratios of film A and film B via the adhesive layer AB and the bonding area ratios of film B and film C via the adhesive layer BC were both 95% or more.

Description

Technical Field

[0001] The present invention relates to a laminate suitable for use as an electrical insulating film for a motor. Background Art

[0002] As insulating materials for drive motors in electric and hybrid vehicles, or compressor motors (for commercial or household use, or for in-vehicle air conditioning), polyester films with excellent electrical insulation and mechanical strength, or aromatic polyamide nonwoven fabrics or polyphenylene sulfide films with improved heat resistance and chemical resistance, or laminates of these have been used.

[0003] For example, studies have been conducted on laminates formed by laminating relatively inexpensive polyester films with an aramid nonwoven fabric and a polyphenylene sulfide film having excellent durability. Patent Document 1 discloses a laminate formed by laminating polyphenylene sulfide films on both sides of a polyethylene terephthalate film with an adhesive layer therebetween, and Patent Document 2 discloses a laminate formed by laminating aramid nonwoven fabric on both sides of a polyethylene terephthalate film with an adhesive layer therebetween.

[0004] Prior art literature

[0005] Patent Literature

[0006] Patent Document 1: Japanese Patent Application Laid-Open No. 2016-163948

[0007] Patent Document 2: Japanese Patent Application Laid-Open No. 2006-262687 Summary of the Invention

[0008] Problems to be solved by the invention

[0009] In recent years, the miniaturization and increased output of motors have led to rising operating temperatures, necessitating increased durability of insulating materials used in motors in high-temperature environments. Furthermore, as operating temperatures rise, the use of oil-cooled motors, which cool the motors with oil known as automatic transmission fluid (ATF), is increasing. Consequently, insulating materials are also required to have improved durability (oil resistance) to ATF. Furthermore, ATF contains trace amounts of water, requiring resistance to moisture and heat. Furthermore, with the widespread adoption of products, there is a growing demand for reduced manufacturing costs, leading to a demand for insulators that are both inexpensive and highly durable, and various research efforts are underway.

[0010] The laminates using adhesive layers described in Patent Documents 1 and 2 are useful in terms of electrical insulation or mechanical strength, but there has recently been a desire to develop a laminate that has high heat resistance and minimal dissolution of the adhesive layer when exposed to high-temperature environments, thereby being useful. Furthermore, there is a demand for a laminate that has improved cohesiveness of the adhesive layer or a laminate that suppresses peeling caused by shear stress applied to the adhesive layer and the film interface due to thermal shrinkage of the film. Furthermore, there is a demand for a laminate that, when immersed in automatic transmission fluid, has an adhesive layer that has high oil resistance or resistance to moisture and heat to trace amounts of water contained therein, and that suppresses peeling due to hydrolysis of the adhesive layer or swelling of the oil. By suppressing dissolution or peeling of the adhesive layer, it is expected that a reduction in the electrical insulation properties of the laminate and the motor using the laminate can be suppressed.

[0011] The present invention aims to provide a laminate having excellent adhesion, processability, heat resistance, resistance to moist heat, and oil resistance in response to the above requirements. More specifically, the present invention aims to provide a laminate suitable for use as an electrical insulating film for motors even in harsh high-temperature environments.

[0012] Technical means to solve the problem

[0013] In order to solve the above-mentioned problems, a preferred embodiment of the present invention includes the following configuration.

[0014] (1) A laminate comprising a film A, a film B, and a film C in this order with adhesive layers interposed therebetween (the adhesive layer between the film A and the film B is referred to as the adhesive layer AB, and the adhesive layer between the film B and the film C is referred to as the adhesive layer BC), wherein:

[0015] The maximum value of the heat shrinkage of the film B at 150° C. for 30 minutes is 0.1% or more and 3.0% or less.

[0016] The Martens hardness of the adhesive layer AB and the adhesive layer BC is 1.0 N / mm 2 Above and 4.0N / mm 2 the following,

[0017] When the laminate was immersed in automatic transmission fluid and heat-treated at 150° C. for 10 hours, the bonding area ratios between film A and film B via the adhesive layer AB and the bonding area ratios between film B and film C via the adhesive layer BC were both 95% or more.

[0018] (2) The laminate according to (1), wherein the dispersion component of the surface free energy of the adhesive layer AB and the adhesive layer BC is 20 mN / m or more and 40 mN / m or less, and the sum of the polar component and the hydrogen bonding component is 5 mN / m or more and 20 mN / m or less.

[0019] (3) The laminate according to (1) or (2), wherein the adhesive layer AB and the adhesive layer BC contain a polyether resin and an isocyanate resin having an active hydrogen group, and / or a polyester resin and an isocyanate resin having an active hydrogen group as main components.

[0020] (4) The laminate according to (3), wherein the isocyanate resin contains a urate-modified product of isophorone diisocyanate as a main component.

[0021] (5) The laminate according to (3) or (4), wherein the active hydrogen group of the polyether resin and / or polyester resin is a hydroxyl group,

[0022] The reaction equivalent ratio of the hydroxyl groups (NCO / OH) is 0.7 or more and 0.95 or less.

[0023] (6) A laminate according to any one of (1) to (5), wherein either film A or film C is at least one selected from a sheet containing aromatic polyamide fiber and a polyphenylene sulfide film, and the other film is at least one selected from a polyphenylene sulfide film, a polyimide film, a polyethylene naphthalate film, and a polyethylene terephthalate film.

[0024] (7) A laminate according to any one of (1) to (6), wherein the membrane A and the membrane C are sheets containing aromatic polyamide fibers, and the membrane B is at least one selected from polyphenylene sulfide membrane, polyimide membrane, polyethylene naphthalate membrane, and polyethylene terephthalate membrane.

[0025] (8) The laminate according to any one of (1) to (6), wherein the film A and the film C are polyphenylene sulfide films, and the film B is a polyethylene terephthalate film.

[0026] (9) The laminate according to any one of (1) to (8), which is used for an electrical insulating film of a motor.

[0027] Effects of the Invention

[0028] According to the present invention, a laminate having satisfactory adhesiveness, processability, oil resistance, heat resistance, and moist heat resistance can be obtained, and the laminate can be suitably used as an electrical insulating film for motors even in high-temperature environments. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] Figure 1 This is a side view of a laminated body according to one embodiment of the present invention.

[0030] Explanation of symbols

[0031] 1: Membrane A

[0032] 2: Adhesive layer AB

[0033] 3: Membrane B

[0034] 4: Adhesive layer BC

[0035] 5: Membrane C DETAILED DESCRIPTION

[0036] Hereinafter, the laminated body of the present invention will be described.

[0037] A preferred form of the laminate of the present invention is a laminate having film A, film B, and film C in this order with adhesive layers interposed therebetween (the adhesive layer between film A and film B is referred to as adhesive layer AB, and the adhesive layer between film B and film C is referred to as adhesive layer BC). The laminate of the present invention can be suitably used as an electrical insulating film for a motor. When used as an electrical insulating film for a motor, film A and film C are in contact with the coil, which is the heat generating portion of the motor, and therefore require heat resistance. Heat resistance is similarly required for film B. In addition, in addition to requiring electrical insulation between the coil and the motor housing material, a balance is also required with respect to the mechanical strength required for the molding process described later and the manufacturing cost. In addition, the adhesive layers require adhesion between the films, in particular, no peeling in a durability test.

[0038] like Figure 1 In the laminated body according to one embodiment of the present invention shown in FIG, reference numeral 1 denotes film A, reference numeral 2 denotes adhesive layer AB, reference numeral 3 denotes film B, reference numeral 4 denotes adhesive layer BC, and reference numeral 5 denotes film C.

[0039] Regarding the laminate of the present invention, it is important that the maximum value of the heat shrinkage of the film B after 30 minutes at 150 ° C is 0.1% or more and 3.0% or less. The maximum value of the heat shrinkage after heat treatment at 150 ° C for 30 minutes can be measured by the following method. First, a sample of 20 mm × 150 mm with any direction as the long side is collected. After heat treatment at 150 ° C for 30 minutes, the dimensional change in the long side direction is measured by the method described in Japanese Industrial Standards (JIS) C 2151 (2006). Then, a sample of 20 mm × 150 mm with a straight line obtained by rotating 5 ° clockwise from the long side direction of the previous sample is collected and the same measurement is performed. This operation is repeated until the angle with the long side direction of the initial sample becomes 175 °. The maximum value of all the values ​​obtained is set as the maximum value of the heat shrinkage. In addition, a heat shrinkage of 0.0% means that the size does not change before and after the heat treatment. In addition, when film B expands due to heating, its heat shrinkage is represented by a negative sign. When the maximum value of the heat shrinkage after heat treatment at 150 ° C for 30 minutes is greater than 3.0%, due to the large shrinkage, shear stress will be strongly applied at the interface between the adhesive and each film, and sometimes peeling will occur at the interface between the adhesive layer and each film. When the maximum value of the heat shrinkage is set to less than 0.1%, it is necessary to mainly carry out a long annealing treatment (heat treatment), so the heat load becomes too large and causes the smoothness of film B to decrease. When laminating with film A and film C through the adhesive layer, the contact area with the adhesive is sometimes reduced, resulting in a decrease in close contact strength, so the lower limit of the maximum value of the heat shrinkage is 0.1%. With regard to the same viewpoint, the maximum value of the heat shrinkage of the film B at 150 ° C for 30 minutes is more preferably 0.1% or more and 2.3% or less, and the maximum value is further preferably 0.1% or more and 1.5% or less.

[0040] Annealing is an example of a method for adjusting the maximum thermal shrinkage of film B. Annealing can be performed, for example, by heating film B in an oven. The temperature during annealing is preferably 150°C to 180°C, and the annealing time is preferably 10 to 60 seconds. Film B can be annealed after being cut into easily handleable sizes or by being rolled out from a roll and passed through an oven. However, the method of rolling out from a roll and passing through an oven is preferred because it allows for continuous processing and offers excellent productivity.

[0041] It is important for the laminate of the present invention that the Martens hardness of the adhesive layer AB and the adhesive layer BC be 1.0 N / mm. 2 Above and 4.0N / mm 2Below. The so-called Martens hardness is measured and calculated using the indentation test method based on the International Organization for Standardization (ISO) 14577. During the measurement, an ultra-micro hardness test system (trade name: "Picodentor" (registered trademark) HM500, manufactured by Fischer Instruments Co., Ltd.) can be used for measurement. In the measurement method, the indenter is a Vickers indenter, and an indenter with a diamond regular quadrangular pyramid shape and a maximum diameter of 400 μm can be used. In addition, in order to eliminate the dependence on the thickness of the adhesive layer, the indentation load is set to as small as 0.1 mN, and the indentation depth is set to approximately 1 μm.

[0042] The Martens hardness is less than 1.0N / mm 2 If the adhesive layer has insufficient cohesive force and heat resistance, when used as an electrical insulating film for a motor, the adhesive may foam or dissolve when the temperature of the motor rises, thereby reducing the electrical insulation of the motor. 2 In the case of , the cohesive force of the adhesive layer is too high, and the followability to the base film is poor, so it may not be possible to obtain sufficient adhesion strength between film A and film B, and between film B and film C. From the same point of view, the Martens hardness of the adhesive layer AB and the adhesive layer BC is more preferably 1.5 N / mm 2 Above and 4.0N / mm 2 The Martens hardness can be adjusted by changing the type or amount of the polyether resin or polyester resin having an active hydrogen group, which will be described later, and the isocyanate resin.

[0043] Regarding the laminate of the present invention, it is important that the bonding area ratio of film A and film B separated by the adhesive layer AB, and the bonding area ratio of film B and film C separated by the adhesive layer BC, when immersed in automatic transmission fluid and heat-treated at a temperature of 150°C for 10 hours, are both 95% or more. The bonding area ratio is measured using the following method. First, a 100mm×100mm laminate sample is collected, immersed in automatic transmission fluid and heat-treated at a temperature of 150°C for 10 hours. Then, after measuring the mass of the heat-treated sample, the portion where peeling occurs between the films and the portion where bubbles occur between the films are cut in the thickness direction in a manner that includes film A, film B, and film C. The mass of the cut sample is measured and the ratio before and after cutting is set as the bonding area ratio. Here, the so-called automatic transmission fluid (hereinafter sometimes referred to as automatic fluid) refers to the oil used for lubrication, cooling, and cleaning of automobile transmissions. There are no particular limitations on the type of auto fluid, as long as it is a commonly used substance. It is generally a base oil with various additives blended in. The base oil is typically a mineral oil-based base oil, a synthetic oil-based base oil, or a mixture thereof. Examples of additives include viscosity modifiers and friction modifiers. Examples of auto fluids include Matic Fluid S (manufactured by Nissan Motor Co., Ltd.), Auto Fluid WS (manufactured by Toyota Motor Corporation), and ATF DW-1 (manufactured by Honda Motor Co., Ltd.).

[0044] When the laminate is immersed in automatic transmission fluid and heat-treated at 150°C for 10 hours, and the bonding area ratio of the films separated by the adhesive layer is less than 95%, the adhesive layer may partially foam and dissolve, causing peeling between the films, which may lead to a decrease in the electrical insulation of the laminate and the electrical insulation of the motor.

[0045] It is important for the laminate of the present invention that the maximum thermal shrinkage of film B at 150°C for 30 minutes is 0.1% or more and 3.0% or less, and the Martens hardness of the adhesive layer is 1.0 N / mm 2 Above and 4.0N / mm 2 When the laminate was immersed in automatic transmission fluid and heat-treated at 150°C for 10 hours, the bonding area ratios between film A and film B via the adhesive layer AB, and between film B and film C via the adhesive layer BC, were both 95% or greater. Meeting these requirements ensures adhesion between the films while imparting sufficient cohesive strength, heat resistance, and oil resistance to the adhesive layer. Consequently, even when exposed to automatic transmission fluid in high-temperature environments, the films and adhesive layers will not delaminate, ensuring electrical insulation.

[0046] From the perspective of bonding area ratio, as the preferred range of the maximum value of the thermal shrinkage rate of film B at 150°C for 30 minutes and the Martens hardness of the adhesive layer, it is preferred to set the maximum value of the thermal shrinkage rate to Y and the Martens hardness of the adhesive layer to X, and satisfy the following formula.

[0047] Y≦6.3X-6.9.

[0048] In the laminate of the present invention, it is preferred that the dispersed component of the surface free energy of the adhesive layer AB and the adhesive layer BC is 20 mN / m or more and 40 mN / m or less, and the sum of the polar component and the hydrogen bonding component is 5 mN / m or more and 20 mN / m or less. In other words, it is preferred that the dispersed component of the surface free energy of the adhesive layer AB is 20 mN / m or more and 40 mN / m or less, the dispersed component of the surface free energy of the adhesive layer BC is 20 mN / m or more and 40 mN / m or less, the sum of the polar component and the hydrogen bonding component of the adhesive layer AB is 5 mN / m or more and 20 mN / m or less, and the sum of the polar component and the hydrogen bonding component of the adhesive layer BC is 5 mN / m or more and 20 mN / m or less. Here, surface free energy values ​​were obtained using a contact angle meter CA-D (manufactured by Kyowa Interface Science Co., Ltd.) for four liquids with known surface free energy and their respective components, namely, dispersed components, polar components, and hydrogen bonding components. Based on the contact angle values ​​and the inherent values ​​of dispersed components, polar components, and hydrogen bonding components for each liquid (obtained based on Panzer's Method IV (described in the Journal of the Japan Adhesion Society, vol. 15, No. 3, p. 96)), the following equations derived from the extended Fowkes equation and Young's equation were used to determine the dispersed components, polar components, and hydrogen bonding components on the surfaces of the adhesive layers AB and BC.

[0049] (γSd·γLd) 1 / 2 +(γSp·γLp) 1 / 2 +(γSh·γLh) 1 / 2 =(1+cosθ) / 2

[0050] Here, γLd, γLp, and γLh represent the intrinsic values ​​of the dispersed, polar, and hydrogen-bonded components of the measurement liquid, respectively (obtained using Panzer's Method IV (described in the Journal of the Japan Adhesion Society, vol. 15, No. 3, p. 96)). θ represents the average contact angle of the measurement liquid on the measurement surface. Furthermore, γSd, γSp, and γSh represent the values ​​of the dispersed, polar, and hydrogen-bonded components on the surfaces of adhesive layers AB and BC, respectively. Substituting the intrinsic values ​​and θ into the above equations yields the simultaneous equations to determine the values ​​of the three components on the measurement surface. The sum of the values ​​for the dispersed, polar, and hydrogen-bonded components yields the surface free energy.

[0051] If the dispersed component of the surface free energy of the adhesive layers AB and BC is less than 20 mN / m, and the sum of the polar and hydrogen bonding components is greater than 20 mN / m, the adhesive layers may not be sufficiently hydrophobic, and the trace amount of water contained in the adhesive fluid may cause the adhesive layers to hydrolyze or swell, thereby failing to achieve sufficient durability. If the dispersed component is greater than 40 mN / m, and the sum of the polar and hydrogen bonding components is less than 5 mN / m, the adhesive layers become highly hydrophobic, increasing their affinity for mineral oil, the main component of the adhesive fluid. This may cause the adhesive layers to swell due to the adhesive fluid, potentially leading to film peeling. Furthermore, from the perspective of bonding area ratio, it is more preferable that the dispersed component of the surface free energy of the adhesive layers AB and BC be 39.8 mN / m or less, and the sum of the polar and hydrogen bonding components be 5.0 mN / m or greater.

[0052] The dispersed components, polar components, and hydrogen bonding components of the adhesive layer AB and the adhesive layer BC can be adjusted by changing the type or amount of the polyether resin or polyester resin having an active hydrogen group, which will be described later, and the isocyanate resin.

[0053] Regarding the laminate of the present invention, it is preferred that the adhesive layer AB and the adhesive layer BC include a resin having an active hydrogen group and an isocyanate resin. Examples of the resin having an active hydrogen group include polyether resins, polyester resins, acrylic resins, polycarbonate resins, and the like. From the perspective of being able to suppress the hydrolysis of the polymer main chain under high temperature and high humidity environments and having high durability against hydrolysis, polyether resins are preferred, and / or from the perspective of having heat resistance, polyester resins are preferred, and polyether resins are more preferred. From the perspective of improving the cohesive force and heat resistance of the adhesive layer, in order to impart a cross-linked structure to the adhesive layer, an isocyanate resin having high reactivity with an active hydrogen group is preferred. Here, the so-called active hydrogen group refers to a group having active hydrogen such as a hydroxyl group, a carboxyl group, a thiol group, and a primary or secondary amino group, and is preferably a hydroxyl group having high reactivity with an isocyanate resin. In addition, the adhesive layer AB and the adhesive layer BC are more preferably composed mainly of a polyether resin and an isocyanate resin having an active hydrogen group, and / or a polyester resin and an isocyanate resin having an active hydrogen group. The adhesive layer AB and the adhesive layer BC are further preferably composed mainly of a polyether resin and an isocyanate resin having a hydroxyl group as an active hydrogen group, and / or a polyester resin and an isocyanate resin having a hydroxyl group as an active hydrogen group. The adhesive layer AB and the adhesive layer BC are particularly preferably composed mainly of a polyether resin and an isocyanate resin having a hydroxyl group as an active hydrogen group, or a polyester resin and an isocyanate resin having a hydroxyl group as an active hydrogen group.

[0054] The phrase "containing the polyether resin and isocyanate resin having active hydrogen groups as main components" means that the total content of the polyether resin and isocyanate resin having active hydrogen groups exceeds 50% by mass in 100% by mass of the raw material solid content of the layer.

[0055] The phrase "containing the polyester resin having active hydrogen groups and the isocyanate resin as main components" means that the total content of the polyester resin having active hydrogen groups and the isocyanate resin exceeds 50% by mass in 100% by mass of the raw material solid content of the layer.

[0056] Furthermore, the phrase "containing a polyether resin and an isocyanate resin having an active hydrogen group, and a polyester resin and an isocyanate resin having an active hydrogen group as main components" means that the total content of the polyether resin having an active hydrogen group, the polyester resin having an active hydrogen group, and the isocyanate resin exceeds 50% by mass in 100% by mass of the raw material solid content of the layer.

[0057] Examples of polyether resins having active hydrogen groups include polyether polyols obtained by polymerizing oxirane compounds such as ethylene oxide, propylene oxide, butylene oxide, and tetrahydrofuran using low molecular weight polyols such as water, ethylene glycol, propylene glycol, trimethylolpropane, and glycerol as initiators. In addition to using difunctional polyols, trifunctional or higher polyols may also be used. Furthermore, combinations of polyols with different numbers of functional groups may also be used. Among these, polyether polyurethane polyols are preferably synthesized by reacting polyalkylene glycol and alkanediol monomers having repeating units of 3 or 4 carbon atoms with an organic diisocyanate at a specified ratio. Polyether polyurethane polyols having repeating units of 1 or 2 carbon atoms have high hydrophilicity and tend to readily absorb moisture and swell, resulting in poor resistance to moisture and heat. Polyether polyurethane polyols having repeating units of 5 or more carbon atoms have high crystallinity, making them difficult to produce.

[0058] Examples of polyalkylene glycols used in the synthesis of polyether polyurethane polyols include polytrimethylene glycol and polypropylene glycol, each of which has 3 carbon atoms in its repeating unit, and polytetramethylene glycol and polybutylene glycol, each of which has 4 carbon atoms in its repeating unit. Among these, polyalkylene glycols comprising at least one of polytetramethylene glycol and polypropylene glycol are preferably used, and polyalkylene glycols comprising polytetramethylene glycol are more preferably used. This is because polytetramethylene glycol exhibits high resistance to moisture and heat, in addition to high water resistance and moderate crystallinity.

[0059] In addition, as the organic diisocyanate used in the synthesis of the polyether polyurethane polyol, it is preferred to use an aliphatic diisocyanate or an alicyclic diisocyanate in which the isocyanate group is not directly bonded to an aromatic ring. Even if the aliphatic diisocyanate or the alicyclic diisocyanate degrades due to heat, it is not easy to polymerize (for example, dimerize), thereby preventing discoloration (discoloration to yellow) over time.

[0060] The polyether resin having an active hydrogen group preferably has a weight-average molecular weight in the range of 35,000 to 70,000. If the weight-average molecular weight is less than 35,000, the initial cohesive force of the adhesive layer composition is insufficient, and when bonding a polyethylene terephthalate film to a polyphenylene sulfide film, lifting may occur between the films. On the other hand, if the weight-average molecular weight exceeds 70,000, the initial cohesive force of the adhesive layer composition is sufficient, but the viscosity may be too high, limiting the coating method.

[0061] Examples of polyester resins having active hydrogen groups include polyester polyols obtained by polycondensing aliphatic dicarboxylic acids (e.g., succinic acid, adipic acid, sebacic acid, glutaric acid, azelaic acid, etc.) and / or aromatic dicarboxylic acids (e.g., isophthalic acid, terephthalic acid, etc.) with low molecular weight diols (e.g., ethylene glycol, 1,2-propylene glycol, 1,3-propylene glycol, 1,4-butanediol, 1,6-hexamethylene glycol, neopentyl glycol, 1,4-bishydroxymethylcyclohexane, etc.).

[0062] Specific examples of such polyester polyols include polyethylene adipate diol, polybutylene adipate diol, polyhexamethylene adipate diol, polyneopentyl adipate diol, polyethylene adipate / butylene adipate diol, polyneopentyl adipate / hexyl adipate diol, poly3-methylpentane adipate diol, polybutylene isophthalate diol, polycaprolactone diol, and poly-3-methylvalerolactone diol.

[0063] As isocyanate resin, as long as it is the compound with a plurality of isocyanate groups in the molecule, it is not particularly limited.As the example of isocyanate resin, can enumerate: polyisocyanate compounds such as toluene diisocyanate, hexamethylene diisocyanate, isophorone diisocyanate, xylylene diisocyanate, hydrogenated xylylene diisocyanate, diphenylmethane diisocyanate, hydrogenated diphenylmethane diisocyanate, tetramethyl xylylene diisocyanate, naphthalene diisocyanate, triphenylmethane triisocyanate, polymethylene polyphenyl isocyanate etc.In addition, these isocyanate resins can be used alone, also can be used as two or more mixtures.In addition, also can be used as modified bodies such as allophanate modified body, biuret modified body, urate modified body. Among them, the urate modified isophorone diisocyanate is preferred, as it has moderate flexibility and excellent adhesion, as well as excellent hydrophobicity and cohesiveness, and can improve moisture-heat resistance and heat resistance. More preferably, the isocyanate resin contains the urate modified isophorone diisocyanate as the main component. The isocyanate resin containing the urate modified isophorone diisocyanate as the main component means that the urate modified isophorone diisocyanate contains more than 50% by mass of the urate modified isophorone diisocyanate in 100% by mass of the isocyanate component in the adhesive layer raw material.

[0064] As the mixing ratio of the isocyanate resin, the reaction equivalent ratio (NCO / OH) of the isocyanate group of the isocyanate resin to the hydroxyl group as the active hydrogen group is preferably 0.7 or more and 0.95 or less. When it is less than 0.7, the crosslinking at the isocyanate resin becomes insufficient, and sometimes the heat resistance is reduced. When it is greater than 0.95, the cohesive force of the adhesive becomes too high, and the adhesive becomes too hard, so sometimes the adhesion strength between the films is reduced.

[0065] Regarding the adhesive layer of the present invention, it is preferred that the active hydrogen groups of the polyether resin and / or polyester resin having an active hydrogen group are hydroxyl groups, and the isophorone diisocyanate resin containing a urate modification has a reaction equivalent ratio (NCO / OH) of hydroxyl groups of not less than 0.7 and not more than 0.95. By satisfying all of these requirements, while giving the adhesive layer sufficient cohesion and heat resistance, it also has excellent moisture and heat resistance as a resin skeleton. Therefore, even when exposed to high temperature and high humidity environments, the films and adhesives will not peel off, and electrical insulation can be ensured. In addition, durability can be improved for trace amounts of water contained in automatic transmission fluid, and both moisture and heat resistance and oil resistance can be imparted. In addition, in the above embodiment, it is more preferred that the active hydrogen groups of the polyether resin or polyester resin having an active hydrogen group are hydroxyl groups, and the isophorone diisocyanate resin containing a urate modification has a reaction equivalent ratio (NCO / OH) of hydroxyl groups of not less than 0.7 and not more than 0.95.

[0066] The adhesive layer can be formed by coating a coating material containing the adhesive layer on each film using a coating method such as a roll coating method, a gravure roll coating method, a kiss coating method, or a printing method, and then drying the coating material. The coating amount of the adhesive layer is preferably 1 g / m2 in terms of solid content in a dry state. 2 ~30g / m 2 , more preferably 3g / m 2 ~20g / m 2 In less than 1g / m 2 In the case of more than 30g / m, the cohesive force of the adhesive layer may become insufficient and the adhesion may be poor. 2 In the case of a plurality of films, the shrinkage stress of the adhesive layer is too high, and the stress inside the roller when the laminate is wound into a roll becomes too large, sometimes causing wrinkles. In addition, the debris during the cutting process adheres to the adhesive layer portion of the cross-section exposed by the slit or punch cutting process, which sometimes leads to reduced productivity. In addition, the economic efficiency is sometimes poor. By laminating film A, film B, and film C using the adhesive layer, the laminate of the present invention can be obtained.

[0067] Within the scope that does not impair the effects of the present invention, various adhesive layers may contain one or more heat-resistant stabilizers, oxidation-resistant stabilizers, ultraviolet absorbers, ultraviolet stabilizers, organic / inorganic lubricants, organic / inorganic microparticles, fillers, nucleating agents, dyes, coupling agents, adhesion-imparting agents and other additives as needed.

[0068] As a method for producing the laminate of the present invention, for example, the following method can be preferably employed. An adhesive is applied to film A and dried to form an adhesive layer AB. Subsequently, film B is laminated so as to be in contact with adhesive layer AB, thereby producing an intermediate laminate. Subsequently, an adhesive is applied to film C and dried to form adhesive layer BC. The surface of film B of the intermediate laminate is laminated so as to be in contact with adhesive layer BC of film C, thereby producing a laminate.

[0069] Here, the adhesive for bonding layer AB and the adhesive for bonding layer BC preferably have as main components a polyether resin and an isocyanate resin having active hydrogen groups in their solid content, and / or a polyester resin and an isocyanate resin having active hydrogen groups. Furthermore, it is more preferred that the isocyanate resin have as main component a urate-modified form of isophorone diisocyanate, and it is even more preferred that the active hydrogen groups in the adhesive for bonding layer AB and the adhesive for bonding layer BC be hydroxyl groups, with the reaction equivalent ratio (NCO / OH) of hydroxyl groups being 0.7 or greater and 0.95 or less. The definitions of the main components shall be based on the definitions in the description of the adhesive layer.

[0070] Regarding the laminate of the present invention, it is preferred that either film A or film C is at least one selected from a sheet containing aromatic polyamide fiber and a polyphenylene sulfide film, and the other film is at least one selected from a polyphenylene sulfide film, a polyimide film, a polyethylene naphthalate film, and a polyethylene terephthalate film.

[0071] That is, membrane B is at least one selected from polyphenylene sulfide film, polyimide film, polyethylene naphthalate film, and polyethylene terephthalate film, and on this basis includes: membrane A and membrane C are in the form of containing aromatic polyamide fibers; membrane A and membrane C are in the form of polyphenylene sulfide membrane; membrane A is a sheet containing aromatic polyamide fibers and membrane C is in the form of polyphenylene sulfide membrane; membrane C is a sheet containing aromatic polyamide fibers and membrane A is in the form of polyphenylene sulfide membrane.

[0072] The sheet containing aromatic polyamide fibers is a paper-like sheet containing aromatic polyamide fibers, more preferably a sheet containing fibers containing benzene rings in addition to amide groups (wholly aromatic polyamide fibers) obtained by polycondensing phenylenediamine and phthalic acid, i.e., a paper-like sheet called "aramid paper." Examples of the aramid paper include "Nomex paper" commercially available from DuPont Teijin Fine Paper Co., Ltd.

[0073] By using a heat-resistant sheet containing aromatic polyamide fibers or a polyphenylene sulfide film in Film A and / or Film C, durability against heating of the coil can be achieved when used as a motor insulation film. By using a polyphenylene sulfide film, a polyimide film, a polyethylene naphthalate film, or a polyethylene terephthalate film in Film B, heat resistance, oil resistance, and electrical insulation properties can be imparted. Aromatic polyamide fiber sheets and polyphenylene sulfide films have excellent heat resistance, resistance to moist heat, and oil resistance, making them suitable for applications requiring long-term durability in high-temperature environments. Furthermore, from the perspective of heat resistance, it is preferred that at least one of Film A and Film C be a sheet containing aromatic polyamide fibers.

[0074] Among them, with respect to the laminate of the present invention, it is more preferred that film A and film C are sheets comprising aromatic polyamide fibers, and film B is at least one selected from polyphenylene sulfide film, polyimide film, polyethylene naphthalate film, and polyethylene terephthalate film. Among them, it is further preferred that film B is a polyphenylene sulfide film. It is further preferred that the sheet comprising aromatic polyamide fibers is a sheet of fibers (wholly aromatic polyamide fibers) comprising benzene rings other than amide groups, which is a polycondensate of phenylenediamine and phthalic acid, or a paper-like sheet such as "aramid paper". By using a sheet comprising aromatic polyamide fibers having excellent heat resistance in film A and film C, it is possible to further obtain durability against heating of the coil when used as a motor insulating film. Although the sheet comprising aromatic polyamide fibers has excellent heat resistance, it is sometimes lacking in electrical insulation because it is a paper-like sheet. However, by using a polyphenylene sulfide film in film B, heat resistance, oil resistance, and electrical insulation can be imparted. Aromatic polyamide fiber-containing sheets and polyphenylene sulfide films are excellent in heat resistance, moist heat resistance, and oil resistance, and therefore can be suitably used in applications requiring long-term durability in high-temperature environments.

[0075] In another embodiment of the laminate of the present invention, preferably, film A and film C are polyphenylene sulfide films, and film B is a polyethylene terephthalate film. While the polyphenylene sulfide film imparts heat resistance, oil resistance, and resistance to heat and humidity, the polyethylene terephthalate film also imparts electrical insulation and mechanical strength, particularly the mechanical strength required for molding into an electrical insulating film for motors, as described below. Polyethylene terephthalate films offer an excellent balance between electrical insulation, mechanical strength, and manufacturing costs, but their heat and heat resistance pose challenges, sometimes limiting their use environments. However, polyphenylene sulfide films with excellent heat and heat resistance can provide a laminate that maintains heat resistance while offering excellent manufacturing costs.

[0076] In terms of heat resistance, it is preferable that the polyphenylene sulfide film used in the laminate of the present invention is, for example, a film mainly composed of a resin containing 85 mol% or more of p-phenylene sulfide units represented by the following chemical formula (1). The content of p-phenylene sulfide units is preferably 90 mol% or more, and further preferably 97 mol% or more. As structural components other than p-phenylene sulfide, a structure containing a phenylene sulfide component is preferable. Examples thereof include: m-phenylene sulfide units, biphenylene sulfide units, biphenylene ether sulfide units, phenylenesulfone sulfide units, phenylenecarbonyl sulfide units, or a trifunctionalized phenylene sulfide component. In addition, examples of the trifunctionalized phenylene sulfide component include a trifunctionalized phenylene sulfide component that can be used to introduce a branched chain into the molecule and is obtained by using 1,2,4-trichlorobenzene during synthesis.

[0077] [Chemical Formula 1]

[0078]

Chemical Formula 1

[0079] [[ID=ll]]

[0080] The polyphenylene sulfide film used in the laminate of the present invention is preferably manufactured, for example, by the following steps. The polyphenylene sulfide raw material is melted at 290°C to 360°C, formed into a film shape using a slit die, and then wound around a casting drum with a surface temperature of 20°C to 70°C to be cooled and solidified, thereby producing an unstretched film. Subsequently, it is uniaxially stretched 3.0 to 5.0 times in the long side direction at 90°C to 120°C, thereby obtaining a uniaxially stretched film. Then, the uniaxially stretched film is introduced into a tenter, preheated at 90°C to 120°C, and then biaxially stretched 2.0 to 4.0 times in the width direction and heat-treated at 200°C to 280°C, thereby obtaining a biaxially oriented polyphenylene sulfide film. In addition, it is not necessarily limited to the manufacturing method shown here.

[0081] The polyethylene terephthalate film used in the present invention is a layer mainly composed of a polyethylene terephthalate resin, and the polyethylene terephthalate resin has an ester bond containing an ethylene terephthalate structure as the main bonding chain of the main chain. When comprehensively judging factors such as quality and economy, it is preferable that the resin constituting the polyethylene terephthalate contains 80 mol% or more of ethylene terephthalate structural components. Within the range that does not impair the effects of the present invention, for example, structural components such as ethylene 2,6-naphthalenedicarboxylate, butylene terephthalate, and ethylene α,β-bis(2-chlorophenoxy)ethane-4,4'-dicarboxylate can also be copolymerized within the range of 20 mol% or less.

[0082] The polyethylene terephthalate film used in the present invention is preferably manufactured by, for example, the following process. The polyester raw material is melted at 270°C to 320°C, formed into a film using a slit-shaped mold, and then wound on a casting drum with a surface temperature of 20°C to 70°C to cool and solidify, thereby making an unstretched film. Subsequently, it is stretched 2.5 times to 3.5 times in the longitudinal direction at 60°C to 120°C to obtain a uniaxially stretched film. The uniaxially stretched film is then introduced into a tenter, preheated at 100°C to 140°C, stretched 2.5 times to 4.0 times in the width direction, and heat-treated at 215°C to 235°C to obtain a biaxially oriented polyethylene terephthalate film. It is also possible to further stretch it again in the longitudinal or transverse direction, or in both the longitudinal and transverse directions before the heat treatment to increase the strength. In addition, it is not necessarily limited to the manufacturing method shown here. It is also possible not to adopt the two-stage stretching method as described above, for example, to manufacture it by a simultaneous biaxial stretching method. Furthermore, in order to reduce thermal shrinkage when exposed to a high temperature environment, the polyethylene terephthalate film may be subjected to an annealing treatment. Annealing can be performed, for example, by heating the polyethylene terephthalate film in an oven. The temperature during the annealing treatment is preferably 150°C to 180°C, and the annealing treatment time is preferably 10 seconds to 60 seconds. The polyethylene terephthalate film can be cut into a size that is easy to handle and then annealed, or it can be rolled out from a roll and annealed in an oven. In terms of continuous processing and excellent productivity, the method of rolling out from a roll and passing through an oven is preferred.

[0083] Various additives, such as antioxidants, heat stabilizers, weather stabilizers, ultraviolet absorbers, organic lubricants, pigments, dyes, organic or inorganic microparticles, fillers, antistatic agents, nucleating agents, crosslinking agents, etc., may be added to the resin constituting the polyethylene terephthalate film or polyphenylene sulfide film used in the laminate of the present invention to the extent that the properties thereof are not deteriorated.

[0084] The thickness of film A and film C is preferably 9 μm or more and 125 μm or less, respectively. In the case of less than 9 μm, the thickness of film A and film C with high heat resistance is reduced, and the ratio of the thickness of film B becomes larger, so the heat resistance of the laminate may be reduced. In the case where the thickness of film A and film C is greater than 125 μm, the ratio of the thickness of film A and film C becomes larger, the end crack resistance of the laminate is reduced, and it may break when a molding process is implemented to form it into an electrical insulating film for motors. In addition, the sheet material or polyphenylene sulfide film containing aromatic polyamide fiber as film A and film C with excellent heat resistance is more expensive than the material of film B, and may be disadvantageous from an economic point of view. Here, the so-called molding process for forming it into an electrical insulating film for motors refers to the process of inserting the laminate into the coil filling portion called the slot of the motor stator, and refers to a series of processes of bending the laminate into a U-shape (a so-called U-shape with two corners) according to the shape of the slot and inserting it into the slot.

[0085] The thickness of film B is preferably 75 μm or more and 300 μm or less. When the thickness of film B is less than 75 μm, the mechanical strength and end crack resistance of the laminate are reduced. When the laminate is formed into an electrical insulating film for motors, it may sometimes break or bend, resulting in poor processability. In particular, when films A and C are sheets containing aromatic polyamide fibers, the electrical insulation is low and the thickness ratio becomes high, which sometimes results in poor electrical insulation. When the thickness of film B is 300 μm or more, the mechanical strength of the laminate becomes too high, making it difficult to bend into a U-shape, resulting in reduced processability.

[0086] Furthermore, from the viewpoints described so far, as one aspect of the present invention, an electrical insulating film for a motor including the laminated body can be preferably cited.

[0087] Example

[0088] [Measurement of physical properties]

[0089] The following examples will further illustrate the structure and effects of the present invention. The present invention is not limited to the following examples. Before describing each example, the measurement methods of various physical properties are described.

[0090] (1) Adhesion strength

[0091] After laminating the film A, film B, and film C of the present invention using the method described in the examples, aging was performed for 72 hours using a thermostat adjusted to 40°C. Three test pieces for measurement were cut out from the laminated sample in a 10 mm wide strip shape. The side containing the film B of the present invention was fixed horizontally, and the film A or film C side was peeled off at a peeling angle of 180° and a tensile speed of 200 mm / min to measure the adhesion strength. The measurement was performed once for each of the three strip test pieces, and the average value of the obtained strengths was set as the value of the adhesion strength. The evaluation was performed according to the following benchmarks, with A and B being qualified.

[0092] A: Adhesion strength is 3N / 10mm or more

[0093] B: Adhesion strength is 2N / 10mm or more and less than 3N / 10mm

[0094] C: Adhesion strength is less than 2 N / 10 mm.

[0095] (2) Thermal shrinkage

[0096] First, a 20mm × 150mm laminate sample with an arbitrary straight line as the long side is collected from the laminate. Then, film A, film C and the adhesive layer are removed and only film B is isolated. After the separated film B is heat-treated at 150 ° C for 30 minutes in an oven (GPHH-202) manufactured by Espec, the dimensional change rate in the long side direction is measured based on JIS C 2151 (2006). Then, a 20mm × 150mm sample with a straight line obtained by rotating 5 ° to the right from the long side direction of the previous sample as the long side is collected and the same measurement is performed. This operation is repeated until the angle with the long side direction of the initial sample becomes 175 °. The maximum value of all the values ​​obtained is set to the maximum value of the thermal shrinkage.

[0097] (3) Martens hardness

[0098] The laminate is cut at right angles to the film surface using a microtome. Subsequently, a cutting device, SAICAS (DN-20S model), manufactured by DAIPLA WINTES, is used to remove only a portion of film A or film C, exposing the adhesive layer to a size of 5 mm × 5 mm or more. Based on the indentation test method according to ISO 14577, an ultra-micro hardness test system (trade name: "Picodentor" (registered trademark) HM500, manufactured by Fischer Instruments Co., Ltd.) is used to press the indenter into the exposed adhesive layer surface for measurement. Furthermore, in order to eliminate dependence on the thickness of the adhesive layer, the indentation load is set as small as 0.1 mN, making the indentation depth approximately 1 μm.

[0099] (4) Determination of dispersed components, polar components, and hydrogen bond components

[0100] A 50 mm x 50 mm laminate sample was collected and partially removed from Film A or Film C using a SAICAS (DN-20S) cutting device manufactured by DAIPLA WINTES, exposing a 5 mm x 5 mm or larger adhesive layer. The contact angles of each solution with the adhesive layer were measured five times using water, ethylene glycol, formamide, and diiodomethane. The average contact angle for each liquid was calculated. The average contact angle values ​​were used to calculate the values ​​for each component using the following formula derived from the extended Fowkes and Young equations.

[0101] (γSd·γLd) 1 / 2 +(γSp·γLp) 1 / 2 +(γSh·γLh) 1 / 2 =(1+cosθ) / 2

[0102] Here, γLd, γLp, and γLh represent the intrinsic values ​​of the dispersed component, polar component, and hydrogen-bonded component of the measurement liquid, respectively (obtained using Panzer's Method IV (described in the Journal of the Japan Adhesion Society, vol. 15, No. 3, p. 96)). θ represents the average contact angle of the measurement liquid on the measurement surface. γSd, γSp, and γSh represent the values ​​of the dispersed component, polar component, and hydrogen-bonded component on the adhesive layer surface, respectively. Substituting the intrinsic values ​​and θ into the above equations yields simultaneous equations to determine the values ​​of the three components on the measurement surface.

[0103] (5) Tensile elongation

[0104] A 10 mm wide, 250 mm long sample was collected from the laminate, with the longitudinal direction of the laminate oriented in the longitudinal direction. The sample was stretched in the longitudinal direction according to JIS C 2151 (2006) to determine the elongation at break of the laminate. Each sample was measured five times, and the average of the five results was used as the tensile elongation.

[0105] When the longitudinal direction cannot be determined, the above-mentioned thermal shrinkage rate measurement is performed, and the direction with the largest thermal shrinkage rate is regarded as the longitudinal direction.

[0106] (6) Elongation retention

[0107] A measurement sample of 10 mm in width and 250 mm in length was collected from the laminate in such a way that the long side direction of the laminate became the longitudinal direction. The cut sample was treated for 200 hours in an oven (GPHH-202) manufactured by Espec at a temperature of 180 ° C. The tensile elongation of the laminate before and after the treatment was measured based on JIS C 2151 (2006). The measurement was performed five times for each sample, and the average value of the five times was set as the tensile elongation. For the tensile elongation obtained, the value obtained by dividing the tensile elongation after treatment by the tensile elongation before treatment was set as the elongation retention rate in the heat resistance evaluation, and evaluated according to the following benchmarks.

[0108] A: More than 70%

[0109] B: 50% or more but less than 70%

[0110] C: Less than 50%.

[0111] (7) End crack resistance

[0112] A sample 20 mm wide and 300 mm long was collected from the laminate with the longitudinal direction of the laminate oriented in the longitudinal direction, and measured using test metal fitting B (V-notch type) in accordance with JIS C 2151 (2006). The obtained end crack resistance was evaluated according to the following criteria.

[0113] A: 750N / 20mm or more

[0114] B: 300N / 20mm or more and less than 750N / 20mm

[0115] C: Less than 300N / 20mm.

[0116] When the longitudinal direction cannot be determined, the above-mentioned thermal shrinkage rate measurement is performed, and the direction with the largest thermal shrinkage rate is regarded as the longitudinal direction.

[0117] (8) Bonding area ratio after automatic liquid immersion

[0118] A 100mm×100mm measurement sample was collected from the laminate. Then, the entire sample was immersed in a stainless steel container containing Nissan's pure automatic fluid (matic fluid S) in an automatic fluid manner, and 0.5% by mass of water was added relative to the amount of automatic fluid to seal the container. The sealed container was placed in an oven (GPHH-202) manufactured by Espec and heat treated at 150°C for 10 hours. Then, the mass of the heat-treated sample was measured, and the portion where the film peeled off and the portion where bubbles were generated between the films were cut in the thickness direction in a manner including film A, film B, and film C. The mass of the cut sample was measured and the ratio before and after cutting was set as the bonding area ratio, and the bonding area ratio was evaluated according to the following benchmarks.

[0119] A: Bonding area rate is more than 98%

[0120] B: Bonding area ratio is 95% or more and less than 98%

[0121] C: The bonding area ratio is less than 95%.

[0122] [Films used for each layer]

[0123] 1. Polyethylene terephthalate (hereinafter referred to as PET (polyethylene terephthalate)) film A (PET-A)

[0124] 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. The temperature was then lowered to 225°C, and after adding 0.08 parts by mass of calcium acetate and 0.029 parts by mass of antimony trioxide, 16.9 parts by mass of ethylene glycol were gradually added over 2 hours while stirring, and methanol was distilled off to terminate the transesterification reaction. Subsequently, 0.16 parts by mass of lithium acetate and 0.11 parts by mass of trimethyl phosphate were added, and the mixture was transferred to a polymerization reaction tank. Subsequently, the polymerization reaction was carried out under reduced pressure with a final temperature of 285°C and a pressure of 13 Pa, thereby obtaining a polyester having an intrinsic viscosity (IV) of 0.54 and 18 equivalents / t of terminal carboxyl groups. The polyester was cut into rectangular blocks with sides of 2 mm × 4 mm × 4 mm, and then dried at 160° C. for 6 hours to crystallize. Then, solid-phase polymerization was carried out at 220° C. for 20 hours under reduced pressure conditions of 65 Pa to obtain polyester resin particles 1 having an intrinsic viscosity (IV) of 0.80, a carboxyl terminal group content of 10 equivalents / t, and a melting point of 260° C.

[0125] Then, the polyester resin pellets 1 were dried at 160°C in a vacuum for 6 hours, supplied to an extruder and melt-extruded at 295°C. After filtering using a filter with an average mesh size of 60 μm made by sintering and compressing stainless steel fibers, the film was extruded from a T-shaped die into a sheet, and then wound onto a mirror-finished casting drum with a surface temperature of 20°C using an electrostatic casting method for cooling and solidification. In addition, at this time, the melting time of the resin from the front end of the extruder to the die was 2 minutes. Furthermore, cold air at a temperature of 10°C was blown from a slit nozzle with a gap of 2 mm in 12 sections along the longitudinal direction at a wind speed of 20 m / s from the opposite side of the casting drum to cool the film from both sides. After preheating the unstretched film to 80°C using a preheating roller, it was stretched 3.3 times in the longitudinal direction using the peripheral speed difference between the rollers while being heated to 90°C using a radiant heater, and then cooled to 25°C using a cooling roller to form a uniaxially oriented film. The uniaxially oriented film was gripped at both widthwise ends with clamps and preheated in an oven at an ambient temperature of 110°C. It was then continuously stretched 3.7 times in the widthwise direction in a stretching zone at 120°C. The resulting biaxially oriented film was then heat-treated at a heat setting temperature of 215°C for 10 seconds. The film was then cooled from 215°C to 160°C while the distance between the clamps facing each other in the widthwise direction was shortened, resulting in a 5.0% relaxation. After cooling to 100°C in the oven, the clamps gripping both widthwise ends of the film were separated, and the film was removed from the oven. The widthwise ends were cut and removed, and the film was wound to obtain a 125 μm thick PET film A. The physical properties of the resulting film are shown in Table 1.

[0126] 2. PET film B to PET film J (PET-B to PET-J)

[0127] PET film A, thickness, heat setting temperature, and annealing time were as shown in Table 1. PET films B to PET films J were obtained in the same manner as above. Table 1 shows the physical properties of the obtained films.

[0128] [Table 1]

[0129] [Table 1]

[0130]

[0131] 3. Polyphenylene sulfide (hereinafter referred to as PPS (Polyphenylene sulfide)) membrane K (PPS-K)

[0132] 100 mol parts of sodium sulfide nonahydrate, 45 mol parts of sodium acetate and 259 mol parts of N-methyl-2-pyrrolidone (NMP) were added to the autoclave and gradually heated to 220°C while stirring. The water was removed by distillation. 101 mol parts of p-dichlorobenzene as the main component monomer, 0.2 mol parts of 1,2,4-trichlorobenzene as the auxiliary component and 52 mol parts of NMP were added to the system after dehydration. The mixture was heated at 170°C at a speed of 3 kg / cm 2 After pressurizing and enclosing nitrogen, the temperature was raised and polymerization was carried out at 260°C for 4 hours. After completion of polymerization, the mixture was cooled and the polymer was precipitated in distilled water. The resulting polymer lumps were collected through a 150-mesh metal screen. The resulting polymer lumps were washed five times with 90°C distilled water and then dried at 120°C under reduced pressure to obtain a PPS raw material powder with a melting point of 280°C. The resulting PPS raw material powder was extruded into a catgut shape using a 30 mm diameter twin-screw extruder at 320°C and then cut to obtain PPS resin pellets 1.

[0133] Next, 7 wt % of calcium carbonate powder having an average particle size of 1.0 μm was added to the PPS resin pellets 1 and uniformly dispersed and prepared. The pellets were extruded into a gut-like shape at 320° C. using a 30 mmφ twin-screw extruder and then cut to obtain PPS resin pellets 2 containing calcium carbonate particles.

[0134] PPS resin pellets 1 and 2 were mixed at a weight ratio of 90:10 and dried at 180°C for 4 hours in a rotary vacuum dryer under a reduced pressure of 3 mmHg. The mixture was then melt-extruded at 310°C in an extruder. After filtration through a filter with an average mesh size of 14 μm, made by sintering and compressing stainless steel fibers, the film was extruded from a T-die into a sheet. Using an electrostatic casting method, the film was wound onto a mirror-finished casting drum at a surface temperature of 25°C and allowed to cool and solidify. The unstretched film was preheated to 92°C using preheating rollers. The film was then stretched 3.7 times in the longitudinal direction while being heated to 105°C using a radiant heater, utilizing the circumferential speed difference between the rollers. The film was then cooled to 25°C using cooling rollers to produce a uniaxially oriented film. The film was then gripped at both ends in the width direction with clamps and preheated in an oven at an ambient temperature of 100°C. The film was then continuously stretched 3.4 times in the width direction in a stretching zone at 100°C. The obtained biaxially oriented film was heat treated in a heating zone at 260°C for 6 seconds, then cooled from 260°C to 200°C while shortening the distance between the clamps facing each other in the width direction, thereby performing a 5.0% relaxation treatment. After cooling to 115°C in an oven, the clamps holding the film at both ends in the width direction were separated, and the film was removed from the oven. The width ends were cut and removed, and the film was transported using transport rollers and then wound up to obtain a biaxially oriented film with a thickness of 16 μm. The obtained film was then subjected to a treatment intensity E value of 30 W·min / m in an air environment. 2 Only one surface was subjected to corona discharge treatment to obtain a PPS film K. The properties of the obtained PPS film are shown in Table 2. Here, the E value refers to the treatment intensity of the discharge treatment on the film surface, which is defined by the following formula.

[0135] E value = [(applied voltage: V) × (applied current: A)] / [(processing speed: m / min) × (electrode width: m)]

[0136] 4.PPS film L ~ PPS film P (PPS-L ~ PPS-P)

[0137] PPS films L to PPS films P were obtained in the same manner except that the PPS film K and its thickness were as shown in Table 2. Table 2 shows the physical properties of the obtained films.

[0138] [Table 2]

[0139] [Table 2]

[0140] membrane Thickness (μm) Maximum thermal shrinkage (%) PPS-K 16 1.5 PPS-L 115 1.5 PPS-M 115 3.0 PPS-N 115 0.1 PPS-O 115 3.3 PPS-P 115 0.0

[0141] 5. Sheet Q and sheet R (PA-Q and PA-R) made of aromatic polyamide fiber (hereinafter referred to as PA)

[0142] As the sheet material containing aromatic polyamide fibers, a paper-like sheet material of "Nomex" (registered trademark), an aromatic polyamide paper manufactured by DuPont Teijin Fine Paper Co., Ltd., was used. The types of the paper-like sheets are shown in Table 3.

[0143] [Table 3]

[0144] [Table 3]

[0145]

[0146] 6. Adhesive a to adhesive g

[0147] 100 parts by mass of Dynagrand (registered trademark) LIS-7100, a dry laminating agent manufactured by Toyomorton Co., Ltd., a polyether resin having a hydroxyl group in an active hydrogen group, Z4470BA manufactured by Sumika Covestro Urethane Co., Ltd., a hardener containing a urate-modified isophorone diisocyanate resin as the main component, and ethyl acetate were weighed and stirred for 15 minutes to obtain adhesives (Adhesives a to G) having a solids concentration of 33.5% by mass. The reaction equivalent ratio of the isocyanate to the polyether resin having an active hydrogen group in each adhesive was NCO / OH, as shown in Table 4.

[0148]

[0149] 7. Adhesive h, adhesive i

[0150] According to the ratio shown in Table 5, the dry laminator "DYNAGRAND" (registered trademark) TKS-9761 manufactured by Toyomorton (Co., Ltd.), which is a polyester resin having a hydroxyl group in the active hydrogen group, CAT-10 manufactured by Toyomorton (Co., Ltd.), which has a urate-modified toluene diisocyanate resin as the main component in the hardener, and ethyl acetate were measured and stirred for 15 minutes to obtain adhesives having a solid content concentration of 33.5% by mass, namely, Adhesive h and Adhesive i.

[0151] [Table 5]

[0152]

[0153] 8. Adhesive

[0154] "Leocoat" (registered trademark) S-8000E manufactured by Toray Coatex Co., Ltd., which is a polyacrylic resin having a hydroxyl group in the active hydrogen group, "Coronate" (registered trademark) HL manufactured by Tosoh Co., Ltd., which contains a hexamethylene diisocyanate resin as the main component in the hardener, and ethyl acetate were weighed according to the ratio shown in Table 6 and stirred for 15 minutes to obtain an adhesive having a solid content concentration of 13.5% by mass, namely, Adhesive J.

[0155] [Table 6]

[0156]

[0157] (Example 1 to Example 17, Comparative Example 1 to Comparative Example 5)

[0158] Adhesive was applied to Film A using a wire bar and dried at 80°C for 60 seconds to form Adhesive Layer AB. Film B was then laminated so that it was in contact with Adhesive Layer AB, producing an intermediate laminate. Adhesive was then applied to Film C using a wire bar and dried at 80°C for 60 seconds to form Adhesive Layer BC. The surface of Film B of the intermediate laminate was laminated so that it was in contact with Adhesive Layer BC of Film C, producing a laminate. The types of Films A, B, and C, Adhesive Layers AB, and BC are shown in Table 7. The results of their property evaluations are shown in Table 8.

[0159] (Examples 18 to 21, Comparative Examples 6 to 9)

[0160] Adhesive layer AB was applied to film B using a wire bar and dried at 80°C for 60 seconds to form an adhesive layer. Film A was then laminated so that it was in contact with adhesive layer AB, creating an intermediate laminate. Adhesive was then applied to the surface of film B of the intermediate laminate using a wire bar and dried at 80°C for 60 seconds to form adhesive layer BC. Film C was then laminated so that it was in contact with adhesive layer BC, creating a laminate. The types of films A, B, C, adhesive layers AB, and BC are shown in Table 7. The results of their property evaluation are shown in Table 8.

[0161] [Table 7]

[0162]

[0163] [Table 8]

[0164] [Table 8]

[0165]

[0166] Industrial applicability

[0167] The present invention provides a laminate having excellent adhesiveness, processability, oil resistance, heat resistance, and moist heat resistance. The laminate of the present invention can be suitably used as an electrical insulating film for motors.

Claims

1. A laminate comprising a film A, a film B, and a film C in this order with adhesive layers interposed therebetween, wherein the adhesive layer between film A and film B is referred to as adhesive layer AB, and the adhesive layer between film B and film C is referred to as adhesive layer BC, wherein: The maximum value of the heat shrinkage of the film B at 150° C. for 30 minutes is 0.1% or more and 3.0% or less. The Martens hardness of the adhesive layer AB and the adhesive layer BC is 1.0 N / mm 2 Above and 4.0N / mm 2 the following, When the laminate is immersed in automatic transmission fluid and heat-treated at 150° C. for 10 hours, the bonding area ratios of film A and film B via the adhesive layer AB and the bonding area ratios of film B and film C via the adhesive layer BC are both 95% or more. The film A and the film C are sheets containing aromatic polyamide fibers, and the film B is at least one selected from polyphenylene sulfide film, polyimide film, polyethylene naphthalate film, and polyethylene terephthalate film. The thickness of the film A is 9 μm or more and 125 μm or less, The thickness of the film B is 75 μm or more and 300 μm or less, The thickness of the film C is 9 μm or more and 125 μm or less.

2. The laminate according to claim 1, wherein The surface free energy of the adhesive layer AB and the adhesive layer BC has a dispersion component of 20 mN / m to 40 mN / m, and a sum of a polar component and a hydrogen bonding component of 5 mN / m to 20 mN / m.

3. The laminate according to claim 1 or 2, wherein The adhesive layer AB contains more than 50% by mass of at least one resin selected from the group consisting of a first resin, a second resin, and a third resin in 100% by mass of the raw material solid content of the adhesive layer AB. The first resin only contains a polyether resin having an active hydrogen group and an isocyanate resin, The second resin contains only a polyester resin having an active hydrogen group and an isocyanate resin, The third resin only contains a polyether resin having an active hydrogen group, a polyester resin having an active hydrogen group, and an isocyanate resin, The adhesive layer BC contains more than 50% by mass of at least one resin selected from the group consisting of the first resin, the second resin, and the third resin in 100% by mass of the raw material solid content of the adhesive layer BC. The laminate according to claim 3 , wherein: The isocyanate resin contains more than 50% by mass of a urate-modified product of isophorone diisocyanate based on 100% by mass of the isocyanate component.

5. The laminate according to claim 3, wherein The active hydrogen groups of the polyether resin and / or polyester resin are hydroxyl groups, The reaction equivalent ratio of the hydroxyl groups, ie, NCO / OH, is 0.7 or more and 0.95 or less.

6. The laminate according to claim 1 or 2, wherein Film B was a polyethylene terephthalate film.

7. The laminate according to claim 1 or 2, which is used as an electrical insulating film for a motor.

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