JP5394896B2 - Biaxially oriented film composite sheet and method for producing the same - Google Patents

Description

  The present invention relates to a biaxially oriented film composite sheet and a method for producing the same, and more specifically, a biaxially oriented film in which a biaxially oriented thermoplastic resin film and a biaxially oriented polyarylene sulfide non-woven fabric are laminated without using an adhesive. The present invention relates to a composite sheet and a manufacturing method thereof.

In recent years, along with the improvement in the reliability of insulation systems due to the reduction in size and weight of electrical equipment, higher functionality, and increased capacity, motor electrical insulation materials include heat resistance, hydrolysis resistance, heat dissipation, chemical resistance, There is a growing demand for insulating materials that have a good balance of workability and other characteristics.
Conventionally, it is known that (1) a biaxially oriented polyphenylene sulfide film is used as an insulating paper for motors applied in this field (Patent Document 1).
In addition, as a laminated film, it is known that (2) a laminated film of a polyphenylene sulfide (hereinafter sometimes referred to as PPS) film and an unstretched PPS sheet is used as an electrically insulating material (Patent Document 2). Further, (3) one or both sides of a PPS film in which a fiber sheet such as a polymer obtained by condensing aromatic polyamide or aromatic aminocarboxylic acid is laminated (Patent Document 3), (4) PPS film and PPS Laminates with other fiber sheets are known (Patent Documents 4 and 5).
However, the above conventional films, laminated films and laminates have the following problems. When the film of (1) and the laminated film of (2) are used as a motor insulating film, they have poor varnish impregnation properties and poor toughness. For example, when inserted into a motor as a slot liner or wedge for motor insulation, In some cases, it was torn, delamination occurred, or workability was not sufficient. Although the laminate of (3) is rich in heat resistance, the fiber sheet used in the laminate has a high moisture absorption rate and a large dimensional change due to moisture absorption. Further, the fiber sheet is poor in chemical resistance (particularly alkali resistance). The laminate of (4) is balanced in various properties such as varnish impregnation property, chemical resistance, moisture absorption property, etc., but the laminate has a low elongation at break. For example, it is used as a motor insulating slot liner or wedge for a motor. In the case of insertion, there were cases in which tearing, delamination, or workability was not sufficient.

JP-A-55-35456 JP-A-3-227624 JP 60-63158 A JP-A 63-237949 JP-A-8-197689

  Accordingly, an object of the present invention is to solve the various problems as described above, that is, various properties such as heat resistance, chemical resistance, low moisture absorption, interfacial adhesion, and varnish impregnation are balanced, and motor insulation is achieved. The present invention is intended to provide a biaxially oriented film composite sheet having excellent processability for use.

The biaxially oriented film composite sheet of the present invention has the following configuration in order to solve the above problems. That is, the biaxially oriented film composite sheet of the present invention is a composite sheet in which a non-woven fabric (B) layer composed of polyarylene sulfide fibers is laminated without an adhesive on at least one surface of a biaxially oriented thermoplastic resin film (A) layer. The nonwoven fabric (B) layer forms a network in which fibers are fused together, and the glass transition temperature T _gA of the thermoplastic resin constituting the A layer, the polyarylene constituting the B layer. glass transition temperature T _gB sulfide satisfies the following formula (1), I der breaking elongation of the composite sheet is 70% or more, characterized in that for use in a motor insulation paper.

−5 ° C. ≦ T _gB −T _gA ≦ 15 ° C. (1)

Moreover, this invention is a manufacturing method of the biaxially oriented film composite sheet used for the insulating paper for motors , Comprising: The unstretched thermoplastic resin film which satisfy | fills following (1) Formula (Glass transition of resin which comprises this film) After laminating and thermocompression bonding a non-woven fabric composed of polyarylene sulfide fibers (the glass transition temperature of the resin constituting the non-woven fabric is T _gB ) on at least one surface of the T _gA ) without using an adhesive, It is characterized by co-stretching in the axial direction.

  According to the present invention, various properties such as heat resistance, chemical resistance, low hygroscopicity, interfacial adhesion, and varnish impregnation can be balanced and used as an electrically insulating material having excellent processability for motor insulation. .

It is a surface view which shows the "network which the fibers fused together" structure in a nonwoven fabric (B) layer. It is an enlarged view which shows the shape of the "fusion point film | membrane" in the net body in a nonwoven fabric (B) layer.

Hereinafter, the biaxially oriented film composite sheet of the present invention will be described.
The biaxially oriented thermoplastic resin film (A) layer constituting the biaxially oriented film composite sheet of the present invention has a glass transition temperature with polyarylene sulfide constituting the non-woven fabric (B) layer composed of polyarylene sulfide fibers described later. The difference is not particularly limited as long as it satisfies the range described later, and examples thereof include polyester resins such as polyethylene terephthalate and polyethylene naphthalate, and polyarylene sulfide resins such as polyphenylene sulfide, polyphenylene sulfide sulfone, and polyphenylene sulfide ketone.
In the present invention, the glass transition temperature T _gA of the thermoplastic resin constituting the biaxially oriented thermoplastic resin film (A) layer and the glass transition temperature T _gB of the polyarylene sulfide constituting the nonwoven fabric (B) layer are as follows: It is necessary to satisfy the relationship satisfying the expression (1). A preferable range of T _gB -T _gA is 0 ° C. ≦ T _gB −T _gA ≦ 10 ° C., and more preferably 0 ° C. ≦ T _gB −T _gA ≦ 5 ° C. When such T _gB -T _gA is less than ± 5 ° C. and exceeds ± 15 ° C., it becomes difficult to perform co-stretching of the A layer and the B layer, resulting in a film having poor mechanical properties. Moreover, since interfacial adhesiveness falls, the workability as motor insulating paper tends to deteriorate.
−5 ° C. ≦ T _gB −T _gA ≦ 15 ° C. (1)
The polyester resin preferably used for the biaxially oriented thermoplastic resin film (A) layer of the present invention is a polymer comprising a dicarboxylic acid component and a glycol component, or a polymer comprising a hydroxycarboxylic acid component (copolymer). And a mixture of a plurality of types of the polyester resins.
Examples of the dicarboxylic acid component constituting the polyester resin include terephthalic acid, isophthalic acid, phthalic acid, 2,6-naphthalenedicarboxylic acid, 1,4-naphthalenedicarboxylic acid, 1,5-naphthalenedicarboxylic acid, 4,4 ′. -Aromatic dicarboxylic acid components such as diphenyldicarboxylic acid, 4,4'-diphenyl ether dicarboxylic acid, 4,4'-diphenylsulfone dicarboxylic acid, 5-sodium sulfoisophthalic acid, succinic acid, adipic acid, suberic acid, sebacic acid An aliphatic dicarboxylic acid component such as dodecanedioic acid, dimer acid or eicosandioic acid, an alicyclic dicarboxylic acid such as 1,4-cyclohexanedicarboxylic acid, or the like can be used.
Examples of the glycol component include ethylene glycol, 1,2-propylene glycol, 1,3-propylene glycol, neopentyl glycol, 1,3-butanediol, 1,4-butanediol, 1,5-pentanediol, 1,6-hexanediol, 1,2-cyclohexanedimethanol, 1,3-cyclohexanedimethanol, 1,4-cyclohexanedimethanol, diethylene glycol, triethylene glycol, polyalkylene glycol, 2,2'-bis (4 ' -Β-hydroxyethoxyphenyl) propane or the like can be used.
Preferred examples of the polyester resin in the present invention include polyethylene terephthalate, a copolymer of ethylene terephthalate and ethylene naphthalate, and a mixture of polyethylene terephthalate and polyethylene naphthalate.
In order to set the glass transition temperature (T _gA ) of the thermoplastic resin constituting the A layer within the range specified in the present invention, it is preferable to use a mixture of the polyester resin and the polyetherimide.
Among such polyetherimides, the polyetherimide preferably used in the present invention contains an aliphatic, alicyclic or aromatic ether unit and a unit containing an imide ring as a repeating unit, and a polyester resin used in combination. Is a compatible polymer and is not particularly limited as long as it is a polymer having melt moldability. For example, U.S. Pat.Nos. 4,141,927, 2,262,678, 2,606,912, 2,606,914, 2,596,565, 2,596,566, 2,598,478, 2,598,536, 2,599,171, No. 9-48852, Japanese Patent No. 2565556, Japanese Patent No. 2564636, Japanese Patent No. 2564737, Japanese Patent No. 2563548, Japanese Patent No. 2563547, Japanese Patent No. 2558341, Japanese Patent No. 2558339, and Japanese Patent No. 2834580. Any polyetherimide can be used.
As long as the purpose of the present invention is not impaired, a unit containing an imide ring in the main chain of polyetherimide, a structural unit other than an aliphatic, alicyclic or aromatic ether unit, for example, aromatic, aliphatic, aliphatic A cyclic ester unit, an oxycarbonyl unit and the like may be contained.
Specific examples of the polyetherimide include polymers represented by the following general formula.

Here, in the above formula, R1 is a divalent aromatic or aliphatic hydrocarbon group having 6 to 30 carbon atoms, R2 is a divalent aromatic hydrocarbon group having 6 to 30 carbon atoms, From the group consisting of alkylene groups having 2 to 20 carbon atoms, cycloalkylene groups having 2 to 20 carbon atoms, and polydiorganosiloxane groups chain-terminated with alkylene groups having 2 to 8 carbon atoms It is a group having a selected divalent organic group in the main chain.
Examples of R1 and R2 include an aromatic hydrocarbon group represented by the following formula.

(Here, n is a positive positive number.)
In the present invention, 2,2-bis [4- (2,3-dicarboxyphenoxy) having a structural unit represented by the following chemical formula 3 or chemical formula 4 from the viewpoint of compatibility with polyester, cost, melt moldability and the like. ) Phenyl] propane dianhydride and a condensate of m-phenylenediamine or p-phenylenediamine are preferred. This polyetherimide is available from Subic Innovative Plastics under the trade name “Ultem” (registered trademark).

The glass transition temperature of the polyetherimide is preferably 350 ° C. or lower, more preferably 250 ° C. or lower. Among these, 2,2-bis [4- (2,3-dicarboxyphenoxy) phenyl] propane dianhydride A condensate of the product with m-phenylenediamine or p-phenylenediamine is most preferable from the viewpoints of compatibility with polyester, cost, melt moldability and the like. As this polyetherimide, a product known by the trade name “Ultem 1000 or 5000 series” manufactured by Subic Innovative Plastics can be preferably used.
The polyetherimide has the advantage of being compatible with the polyester resin, and when a mixture of the polyetherimide and polyester is used as the thermoplastic resin of the biaxially oriented thermoplastic resin film (A) layer, There is an advantage that the glass transition temperature of the mixture can be easily adjusted within the range specified in the present invention by the content of etherimide.
For example, when polyethylene terephthalate is used, the content of polyetherimide is preferably 5% by weight or more and 30% by weight or less. More preferably, they are 10 weight% or more and 25 weight% or less, More preferably, they are 15 weight% or more and 20 weight% or less. When such a mixture of polyetherimide and polyester is used, there is an advantage that adhesion to the nonwoven fabric (B) layer is also excellent. Further, when the content of the polyetherimide exceeds 30% by weight, the orientation of the polyarylene sulfide layer is lowered, and the elongation at break of the composite sheet is lowered, so that the workability as a motor insulating paper may be lowered. .
In addition, content of polyetherimide in the thermoplastic resin which comprises a biaxially oriented thermoplastic resin film (A) layer can be calculated | required by a well-known method. Next, the example which calculates | requires polyetherimide content in polyester is shown.
The weighed polyetherimide-containing polyester (Xg) is dissolved in a mixed solution of hexafluoroisopropanol and chloroform, and then reprecipitated with acetone to obtain polyester and polyetherimide powdery particles. The polyetherimide component contained in the film constituting the layer (A) from the following formula is obtained by eluting the polyetherimide component into chloroform from the obtained powder particles, filtering out and weighing (Yg). The amount can be calculated.
Polyetherimide content [%] = Y / X × 100
Thus, the glass transition temperature of the polyester resin film can be appropriately adjusted by adding the polyetherimide to the polyester in the above-described range. The glass transition temperature can be determined from differential scanning calorimetry according to JIS K7121.
Moreover, it is preferable to use polyarylene sulfide resin as a thermoplastic resin which comprises the biaxially oriented thermoplastic resin film (A) layer which comprises the biaxially oriented composite sheet of this invention.
The polyarylene sulfide resin used in the present invention is a homopolymer or copolymer having a repeating unit of-(Ar-S)-. Ar includes structural units represented by the following formula (A) to formula (K).

(R1 and R2 are substituents selected from hydrogen, an alkyl group, an alkoxy group, and a halogen group, and R1 and R2 may be the same or different.)
As the polyarylene sulfide resin used in the present invention, it is preferable to use those in which Ar is a structural unit represented by the formula (A) of the above chemical formula 5. Typical examples of these are polyphenylene sulfide and polyphenylene sulfide sulfone. , Polyphenylene sulfide ketone, random copolymers thereof, block copolymers, and mixtures thereof. A particularly preferred polyarylene sulfide is preferably polyphenylene sulfide (PPS) from the viewpoint of film properties and economy. In the present invention, the p-arylene sulfide unit represented by the structural formula shown below is preferably 80 mol% or more, more preferably 90 mol% or more, still more preferably 95 mol%, as the repeating unit of the polyarylene sulfide. A polyarylene sulfide containing the above is a preferred embodiment. If it is less than 80 mol%, the crystallinity and thermal transition temperature of the polymer are low, and the heat resistance, chemical resistance, moisture absorption characteristics, hydrolysis resistance, etc., which are the characteristics of polyarylene sulfide, may be impaired.

  In the polyarylene sulfide, as long as it is less than 20 mol% of the repeating units, other units containing a copolymerizable sulfide bond may be contained. Examples of the copolymerizable repeating unit include a trifunctional unit, an ether unit, a sulfone unit, a ketone unit, a meta bond unit, an aryl unit having a substituent such as an alkyl group, a biphenyl unit, a terphenylene unit, a vinylene unit, and a carbonate. Units and the like are listed as examples, and specific examples include structural units of the following chemical formula (7). One or more of these can coexist. In this case, the structural unit may be either a random type or a block type copolymerization method.

  In the present invention, a PPS resin can be preferably used as the polyarylene sulfide resin. As such PPS resin, there are various methods, for example, a method for obtaining a polymer having a relatively low molecular weight described in JP-B-45-3368, or JP-B-52-12240 and JP-A-61-7332. It can be produced by a method for obtaining a polymer having a relatively large molecular weight described in the publication.

  Next, although the manufacturing method of PPS resin is illustrated, in this invention, it is not limited to this in particular. Polyarylene sulfides other than PPS can be produced in the same manner or by a known method. For example, sodium sulfide and p-dichlorobenzene are reacted in an amide polar solvent such as N-methyl-2-pyrrolidone (NMP) at high temperature and high pressure. If necessary, a copolymer component such as trihalobenzene can be included. Moreover, caustic potash, a carboxylic acid alkali metal salt, etc. can be added as a polymerization degree regulator, and it can be made to polymerize at 230-280 degreeC. After the polymerization, the polymer is cooled, and the polymer is filtered as a water slurry through a filter to obtain a granular polymer. This granular polymer is stirred in an aqueous solution such as acetate at 30 to 100 ° C. for 10 to 60 minutes, washed with ion exchange water at 30 to 80 ° C. several times, and dried to obtain a PPS powder. This powder polymer is washed with NMP at an oxygen partial pressure of 10 torr or less, preferably 5 torr or less, then washed several times with ion-exchanged water at 30 to 80 ° C., and dried under a reduced pressure of 5 torr or less. can do.

The melt viscosity of the PPS resin is preferably in the range of 500 to 12000 poise, more preferably 1000 to 8000 poise, at a temperature of 320 ° C. and a shear rate of 200 sec ⁻¹ from the viewpoint of film forming properties. Is done.

  The biaxially oriented thermoplastic resin film (A) layer of the biaxially oriented film composite sheet of the present invention is a resin composition that preferably contains 90% by weight or more, more preferably 95% by weight or more of the polyarylene sulfide. Good. When the polyarylene sulfide content is less than 90% by weight, the crystallinity is lowered, and the heat resistance, moisture absorption characteristics, hydrolysis resistance, etc. of the composite sheet may be impaired. Examples of the polymer that can be included in the resin composition include various types such as polyamide, polyetherimide, polyethersulfone, polysulfone, polyphenylene ether, polyester, polyarylate, polyamideimide, polycarbonate, polyolefin, and polyetheretherketone. Polymers can be mentioned, and two or more kinds can be used.

The thermoplastic resin constituting the thermoplastic resin film (A) layer of the biaxially oriented film composite sheet of the present invention may be an organic or inorganic filler other than the thermoplastic resin, or inert particles as long as the object of the present invention is not impaired. Etc. may be included.
The above-mentioned polyarylene sulfide resin can be used as the polyarylene sulfide resin constituting the nonwoven fabric (B) layer comprising polyarylene sulfide fibers constituting the biaxially oriented film composite sheet of the present invention.
The nonwoven fabric (B) layer of the biaxially oriented film composite sheet of the present invention forms a network in which fibers are fused as shown in FIG.
In the nonwoven fabric (B) layer, a film is formed between a plurality of fibers coming out from the fusion point at least at a part, preferably all of the fusion points in the network. desirable. The shape of a film formed between a plurality of fibers coming out from the fusion point (hereinafter, this film is referred to as a “fusion point film”) forms a fusion point and a fusion point as shown in FIG. Since it is formed between the sides of a plurality of fibers, it has a so-called “water scooping duck leg” shape or “skin foot scuffing” shape. Moreover, the thickness is smaller than the fiber diameter of the fiber in which the fusion point film | membrane was formed.
The present invention does not form the entire surface of the non-woven fabric (B) layer with such a fusion point film, but a large number of hole-like structures in which the network in the B layer is formed by the water-fusing fusion point film. By configuring in a shape having, the mechanical properties can be further improved and an excellent insulating material can be obtained.
The network having the fusion point film can be formed, for example, by laminating a film and a non-woven fabric, which will be described later, and co-stretching. (B) The strength of the layer can be remarkably increased, and the strength of the biaxially oriented film composite sheet as a whole is excellent. Also, when inserted into a motor, the nonwoven fabric layer tears or delamination occurs. In addition to being remarkably suppressed, the formation of the hole-like structure can simultaneously provide performance excellent in varnish impregnation and moisture absorption.
In such a nonwoven fabric (B) layer, a method for forming a fusion point film is a method of laminating a nonwoven fabric obtained by a melt blow method, which will be described later, by thermocompression bonding with an unstretched thermoplastic resin film. By stretching and heat-treating, fusion between fibers was promoted, and a network having a fusion point film in which a film was formed between a plurality of fibers through a stretching process could be formed. is there. The area of the fusion point film is not particularly limited, but is preferably 1 μm ² or more, more preferably 5 μm ² or more. There is no particular upper limit on the area of the film, but it is preferably 10,000 μm ² or less from the viewpoint of impregnation with varnish or oil.
In this invention, it is preferable that the fusion point film | membrane is formed in all the intersections which the fibers which comprise a nonwoven fabric (B) layer cross and contact. Further, when the nonwoven fabric (B) layer is observed from the upper surface, the number of fusion points where the fusion point film is formed is preferably 1 or more, more preferably 5 or more, particularly preferably 1 mm ^{2 of the} nonwoven fabric layer surface. What is observed with 10 or more is excellent in strength as a biaxially oriented film composite sheet, and when inserted into a motor, the nonwoven fabric (B) layer is significantly suppressed from tearing or delamination. This is preferable because it can be performed.
The method of setting the area and the number of the fusion point films in the above ranges can be adjusted by appropriately adjusting the basis weight of the nonwoven fabric (B) layer to be laminated and by the biaxial stretching stretch ratio described later.
In the biaxially oriented film composite sheet of the present invention, the basis weight of such nonwoven fabric layer (B) is preferably a 1 to 50 g / ^{m 2,} more preferably 3 to 30 g / ^{m 2,} more preferably 5 ˜20 g / m ² . When the weight per unit area is 50 g / m ² or less, the workability at the time of motor insertion can be further improved, and when it is 1 g / m ² or more, the productivity of the biaxially oriented film composite sheet of the present invention can be improved. Can be improved.
For the production of the nonwoven fabric (B) layer constituting the biaxially oriented film composite sheet of the present invention, a known nonwoven fabric production method can be used, but it is easy to produce it by a melt blow method. In the melt-blowing method, when the molten polyarylene sulfide polymer is discharged from the die, hot air is blown from the periphery of the die, the polymer discharged by the hot air is made to have a fine fiber diameter, and then placed on a net conveyor arranged at an appropriate position. It is produced by spraying and collecting to form a web. Since the web is sucked together with hot air by a suction device provided on the net conveyor, the individual fibers are collected before they are completely solidified. Moreover, the orientation of the fibers, the fiber diameter, and the basis weight of the nonwoven fabric can be arbitrarily set by appropriately adjusting the polymer discharge amount, hot air temperature, hot air flow rate, conveyor moving speed, and the like. The fibers constituting the nonwoven fabric are solidified in a non-oriented or low-oriented state, and the crystallinity is preferably 20% or less, more preferably 10% or less, and particularly preferably 5% or less. It is preferable at the point which forms a film | membrane, Furthermore, it is preferable from a viewpoint of the adhesiveness of a film and a nonwoven fabric, and co-stretchability.
Also, the longer the fiber length, the better. Lowering the crystallinity can be achieved by quenching in the process of solidification after discharge from the die.
In the biaxially oriented film composite sheet of the present invention, the nonwoven fabric (B) layer is laminated on at least one surface of the biaxially oriented thermoplastic resin film (A) layer without using an adhesive. It goes without saying that it is possible to adopt any configuration such as a configuration in which the (B) layer is laminated on both sides of the layer) or a configuration in which the (A) layer is laminated on both sides of the (B) layer. Nor.
Next, the method for obtaining the biaxially oriented film composite sheet of the present invention will be described with specific examples. Of course, the present invention is not limited to such examples.
First, it is easy to produce the nonwoven fabric made of polyarylene sulfide fibers to be the nonwoven fabric (B) layer by using the melt blow method described above. After winding up this nonwoven fabric once or continuously, the nonwoven fabric is thermocompression bonded to an unstretched thermoplastic resin film to be a biaxially oriented thermoplastic resin film (A) layer. Here, the method of thermocompression bonding is not particularly limited, but a method of thermocompression bonding with a heating roll is preferably used. In addition, the thermocompression bonding temperature at that time is preferably in the range between the glass transition temperature (Tg) and the melting point (Tm) of the resin constituting the unstretched thermoplastic resin film, more preferably the glass transition. It is preferable to set the temperature (Tg) and the cold crystallization temperature (Tcc). In addition, when roll stretching is performed at the beginning of the stretching process described below, it is possible to simultaneously perform stretching and thermocompression bonding by heating the roll.
Next, the thermocompression laminate obtained in this manner is co-stretched (referring to stretching the laminate in the same state as each layer while being laminated) and biaxially oriented. For co-stretching, sequential biaxial stretching methods (stretching methods that combine stretching in each direction, such as a method of stretching in the width direction after stretching in the longitudinal direction), simultaneous biaxial stretching methods (in the longitudinal direction and the width direction) The method of extending | stretching simultaneously), or the method which combined them can be used.
For example, when the sequential biaxial stretching method is used, the stretching temperature in both the longitudinal direction and the width direction is, in the present invention, the glass transition temperature (Tg) to (Tg + 40) ° C., preferably (Tg + 5) to (Tg + 30) of polyarylene sulfide. ) In the range of ° C., the stretching ratio is 3 to 4 times, preferably 3.1 to 3.8 times, more preferably 3.2 to 3.6 times. After such co-stretching, it is preferable to cool with a cooling roll group of 20 to 50 ° C.
Next, heat setting is performed as necessary. The heat setting temperature is not particularly limited, and it is preferable to perform one-stage or multi-stage heat setting within the range of the cold crystallization temperature (Tcc) to the melting point (Tm) of polyarylene sulfide. The preferred multistage heat setting temperature is 160 to 220 ° C., preferably 180 to 220 ° C. in the first stage, and the maximum temperature of subsequent heat setting and / or relaxation heat treatment is 240 to 280 ° C., Preferably, it is 260-280 degreeC. The heat treatment time is suitably about 0.5 to 60 seconds. Then, it is preferable to perform the relaxation process performed in the width direction, and the relaxation rate is preferably 0.1 to 8%.
In the biaxially oriented film composite sheet of the present invention, the average fiber diameter of the fibers constituting the nonwoven fabric (B) layer is preferably in the range of 1 to 20 μm, more preferably 2 to 15 μm. By setting it as this range, the fiber constituting the nonwoven fabric (B) layer in the biaxially oriented film composite sheet is less likely to be cut or peeled off at the fusion point, also from the viewpoint of the formability of the fusion point film, Furthermore, it is preferable because the strength of the composite sheet can be further increased.
In the biaxially oriented film composite sheet of the present invention, the thickness of the nonwoven fabric (B) layer is preferably 1 to 300 μm, more preferably 5 to 200 μm, and still more preferably 10 to 100 μm. If the thickness exceeds 300 μm, the nonwoven fabric (B) layer may tear when the motor is inserted, or the layers (A) and (B) may delaminate. If the thickness is less than 1 μm, the impregnation of varnish or oil may deteriorate. There is.
The thickness ratio between the biaxially oriented thermoplastic resin film (A) layer and the non-woven fabric (B) layer is preferably 2 or more from the viewpoint of processability when a motor is inserted and the heat resistance of the biaxially oriented film composite sheet. More preferably, it is 5 or more.
The interfacial adhesive strength between the biaxially oriented thermoplastic resin film (A) layer and the nonwoven fabric (B) layer of the biaxially oriented film composite sheet of the present invention is preferably 1 g / cm or more, more preferably 10 g / cm or more. Particularly preferably, it is 30 g / cm or more. The interfacial adhesive strength can be determined by a T-shaped peel test method according to JIS-K-6854. When the interfacial adhesive strength is 1 g / cm or more, bending workability as a slot liner or wedge for motor insulation and punching workability can be further improved.
It is important that the breaking elongation of the biaxially oriented film composite sheet of the present invention is 70% or more. More preferably, it is 80% or more, and more preferably 90% or more. When the elongation at break is less than 70%, bending as a slot liner or wedge for motor insulation or punching workability may deteriorate. The method for setting the elongation at break to 70% or more is that the interfacial adhesive strength between the biaxially oriented thermoplastic resin film (A) layer and the nonwoven fabric (B) layer is within the above preferred range, and the area stretch ratio during film-forming stretching This can be achieved by setting (stretching ratio in the longitudinal direction × stretching ratio in the width direction) to 13 times or less, preferably 12 times or less, and more preferably 11.5 times or less. At this time, heat setting by the above-described multistage heat setting method is preferably used from the viewpoint of improving the flatness of the biaxially oriented film composite sheet.

  The use of the biaxially oriented film composite sheet of the present invention is not particularly limited. For example, electric insulating materials such as motors, transformers, and insulation cables, molding materials, circuit board materials, circuits and optical members, and processes and mold release It is used for various industrial materials such as materials, protective films, lithium ion battery materials, solar cell materials, fuel cell materials, speaker diaphragms, and the like. More specifically, it can be suitably used for electrical insulation materials for water heater motors, compressor motors for car air conditioners used for industrial motors and hybrid vehicles, and drive motors.

The measurement method or evaluation method of physical property values or properties is as follows.
(1) Elongation at break It was measured using an Instron type tensile tester according to the method defined in ASTM-D882. The measurement was performed under the following conditions, and an average value was taken for each of the 10 samples.

Measuring device: Orientec Co., Ltd. film strong elongation automatic measuring device “Tensilon AMF / RTA-100”
Sample size: width 10mm x length 150mm
Between test lengths: 100 mm
Tensile speed: 300 mm / min Measurement environment: 23 ° C.
(2) Glass transition temperature Differential scanning calorimeter Measured according to JIS K7121-1987, using a DSC (RDC220) manufactured by Seiko Instruments Inc. and a disk station (SSC / 5200) manufactured by the same company as a data analyzer. 5 mg of a sample was melted and held at 350 ° C. for 5 minutes on an aluminum saucer, rapidly cooled and solidified, and then heated from room temperature to 350 ° C. at a heating rate of 20 ° C./min. The midpoint temperature observed at this time was defined as the glass transition temperature (Tg).
(3) Melting temperature In the same manner as in (2) above, using a differential scanning calorimeter DSC (RDC220) manufactured by Seiko Instruments Inc. according to JIS K7121-1987, using a disk station (SSC / 5200) manufactured by the same company as a data analyzer, 5 mg of the sample was heated from room temperature to 350 ° C. at a heating rate of 20 ° C./min on an aluminum tray, melted and held at 350 ° C. for 5 minutes, rapidly solidified and held for 5 minutes, and then heated from room temperature to 20 The temperature was raised to 350 ° C at a rate of ° C / min. At that time, the peak temperature of the endothermic peak of melting observed was defined as the melting temperature (Tm).
(4) Melt Viscosity Using a flow tester CFT-500 (manufactured by Shimadzu Corporation), the base length is 10 mm, the base diameter is 1.0 mm, the preheating time is set to 5 minutes, 320 ° C., shear rate 200 / Measured in sec.
(5) Intrinsic viscosity (dl / g)
The value calculated by the following formula from the solution viscosity measured at 25 ° C. in orthochlorophenol was used. That is, ηsp / C = [η] + K [η] 2 · C
Here, ηsp = (solution viscosity / solvent viscosity) −1, C is the weight of dissolved polymer per 100 ml of solvent (g / 100 ml, usually 1.2), and K is the Huggins constant (assuming 0.343). is there. The solution viscosity and solvent viscosity were measured using an Ostwald viscometer. The unit is indicated by [dl / g].
(6) A cellophane tape was attached to the surface of the interfacial adhesive film, and the peel strength between the film and the nonwoven fabric was evaluated using the T-type peel test method based on JIS-K-6854 according to the following criteria.
A: Peel strength is 30 g / cm or more B: Peel strength is 10 g / cm or more and less than 30 g / cm Δ: Peel strength is 1 g / cm or more and less than 10 g / cm x: Peel strength is less than 1 g / cm (7) Reticulated Presence / absence of body structure and number of fusion point films Ten images were taken at a magnification of 450 times at arbitrary 10 locations of the nonwoven fabric with a scanning electron microscope, and the presence / absence of the network structure shown in FIG. 1 and the fibers shown in FIG. The number of 5 μm ² or more fusion point films fused together was evaluated according to the following criteria.
◎: 10 pieces / mm ² or more ○: 5 pieces / mm ² or more, less than 10 pieces / mm ²
Δ: 1 piece / mm ² , less than 5 pieces / mm ² ×: less than 1 piece / mm ² (8) Weight per unit area (g / m ² )
The nonwoven fabric was cut into a size of 20 cm × 20 cm, and the weight was measured and converted into a weight per 1 m ² .
(9) Workability Using a motor slot machine (manufactured by Odawara Engineering Co., Ltd.), processing a sample into a slot with a width of 24 mm and a length of 39 mm at a processing speed of 2 / sec. Were evaluated as defective, and the rate of defective products was evaluated according to the following criteria. The number of processed samples is 100 for each sample.
A: Defect rate is 0%
○: Defect rate exceeds 0% and 5% or less Δ: Defect rate exceeds 5% and 20% or less ×: Defect rate exceeds 20%
(10) Varnish impregnating state After cutting the sample into a size of 10 cm × 10 cm, the following varnish is impregnated by the immersion impregnation method, suspended in a drying apparatus at 150 ° C. for 15 minutes, heated, and then cooled. Were visually observed and evaluated according to the following criteria.
The varnish consists of 85 parts by weight of tetrabromobisphenol A type epoxy resin (Japan Epoxy Resin, “Epicoat 5047”, epoxy equivalent 550), cresol novolak type epoxy resin (Dainippon Ink Chemical Co., Ltd., “Epicron N-690”). , Epoxy equivalent 210) 15 parts by weight, 2.3 parts by weight of dicyandiamide, 0.1 parts by weight of 2-ethyl-4-methylimidazole are dissolved in N, N-dimethylformamide, and a liquid resin having a nonvolatile content of 55% by weight is obtained. Prepared.

  ○: It has excellent impregnation properties and almost no voids are observed.

  (Triangle | delta): The impregnation property is favorable and a little void is observed.

X: Impregnation is poor and many voids are observed.
(Reference Example 1) Polymerization of polyethylene terephthalate 0.14 parts by weight of magnesium acetate tetrahydrate was added to 194 parts by weight of dimethyl terephthalate and 124 parts by weight of ethylene glycol, and the ester exchange reaction was carried out while distilling methanol at 140-230 ° C. went. Next, 0.05 parts by weight of trimethyl phosphate ethylene glycol solution and 0.05 parts by weight of antimony trioxide were added and stirred for 5 minutes, and then the reaction system was heated from 230 ° C. to 290 ° C. while stirring the low polymer at 30 rpm. While gradually raising the temperature to 0 ° C., the pressure was reduced to 0.1 kPa. The time to reach the final temperature and final pressure was both 60 minutes. When the polymerization reaction is carried out for 3 hours and the predetermined stirring torque is reached, the reaction system is purged with nitrogen and returned to normal pressure to stop the polycondensation reaction, discharged into cold water in the form of a strand, and immediately cut to obtain an intrinsic viscosity of 0.63 dl / g. Polyethylene terephthalate (PET) pellets having a melting temperature of 257 ° C. were obtained.
(Reference Example 2) Polymerization of polyethylene naphthalate 100 parts by weight of 2,6-naphthalenedicarboxylic acid dimethyl ester and 60 parts by weight of ethylene glycol, 0.018 parts by weight of magnesium acetate tetrahydrate as a transesterification catalyst, and calcium acetate 1 After adding 0.003 parts by weight of water salt and subjecting it to transesterification at 170-240 ° C. and 0.5 kg / cm ² , 0.004 part by weight of trimethyl phosphate was added to complete the transesterification reaction. Further, 0.23 parts by weight of antimony trioxide was added as a polymerization catalyst, and a polycondensation reaction was performed under high temperature and high vacuum to obtain polyethylene naphthalate (PEN) pellets having an intrinsic viscosity of 0.60 dl / g and a melting temperature of 263 ° C.
(Reference Example 3) In a 70 liter autoclave equipped with a PPS polymerization stirrer, 8,277.37 g (70.00 mol) of 47.5% sodium hydrosulfide, 2,957.21 g (70.97 g) of 96% sodium hydroxide Mol), 11,434.50 g (115.50 mol) of N-methyl-2-pyrrolidone (NMP), 2,583.00 g (31.50 mol) of sodium acetate, and 10,500 g of ion-exchanged water, The mixture was gradually heated to 245 ° C. over about 3 hours while passing nitrogen under pressure, and after distilling 14,780.1 g of water and 280 g of NMP, the reaction vessel was cooled to 160 ° C. The amount of water remaining in the system per mole of the charged alkali metal sulfide was 1.06 mol including the water consumed for the hydrolysis of NMP. The amount of hydrogen sulfide scattered was 0.02 mol per mol of the charged alkali metal sulfide.

  Next, 10,235.46 g (69.63 mol) of p-dichlorobenzene and 9,09.0.00 g (91.00 mol) of NMP were added, the reaction vessel was sealed under nitrogen gas, and the mixture was stirred at 240 rpm. The temperature was raised to 238 ° C. at a rate of 6 ° C./min. After reacting at 238 ° C. for 95 minutes, the temperature was raised to 270 ° C. at a rate of 0.8 ° C./min. After reacting at 270 ° C. for 100 minutes, 1,260 g (70 mol) of water was injected over 15 minutes and cooled to 250 ° C. at a rate of 1.3 ° C./minute. Then, after cooling to 200 ° C. at a rate of 1.0 ° C./min, it was rapidly cooled to near room temperature.

The contents were taken out, diluted with 26,300 g of NMP, the solvent and solid matter were filtered off with a sieve (80 mesh), and the resulting particles were washed with 31,900 g of NMP and filtered off. This was washed several times with 56,000 g of ion-exchanged water, filtered and then washed with 70,000 g of 0.05 wt% aqueous calcium acetate and filtered. After washing with 70,000 g of ion-exchanged water and filtering, the resulting hydrous PPS particles were dried with hot air at 80 ° C. and dried under reduced pressure at 120 ° C. The obtained PPS resin had a melt viscosity of 4000 poise (320 ° C., shear rate of 200 / s), a glass transition temperature of 90 ° C., and a melting point of 280 ° C.
(Reference Example 4) Preparation of PPS pellets The polyphenylene sulfide powder obtained above was supplied to a counter-rotating twin-screw extruder and extruded from a die attached to an extruder held at 300 ° C to obtain PPS pellets.
(Reference Example 5) Preparation of unstretched PPS nonwoven fabric Using a device equipped with a melt blow injection device having 7 orifices per 1 cm width of the base and a gas injection slit gap of 0.3 mm width, the PPS pellets obtained above were rotated It is dried at 180 ° C for 2 hours in a dryer, melted at 315 ° C, extruded through an orifice, and heated at 330 ° C through a gas injection slit and pulled to separate fibers with an average fiber diameter of 9.6 µm from the melt blow injection device by 40 cm. An unstretched PPS nonwoven fabric having a mass per unit area of 20 g / m ² was obtained by collecting on the arranged porous belt.
Example 1
The polyethylene terephthalate resin obtained in Reference Example 1 and “Ultem” 1010 (polyetherimide) manufactured by Savic Innovative Plastics Co., Ltd. were mixed at a ratio of PET / PEI (85/15) (% by weight), and a rotary vacuum dryer. Was vacuum dried at 180 ° C. for 3 hours. The dried polymer was supplied to an extruder, melted at 280 ° C., extruded into a sheet form from a T-type die onto a drum, and cooled and solidified to obtain an unstretched PET / PEI film.
Subsequently, the obtained unstretched PET / PEI film and the unstretched PPS nonwoven fabric obtained in Reference Example 5 were stacked, supplied to a heated roll, and thermocompression bonded at a roll temperature of 95 ° C. The laminated sheet thus obtained was stretched 3.4 times in the longitudinal direction with a silicone rubber stretching roll (pressure roll 1.5 N / cm) heated to 100 ° C., and further fed into a tenter type stretching machine. And then stretched 3.5 times in the width direction (area stretch ratio 11.9 times), heat treated at 200 ° C. for 5 seconds, then heat treated at 265 ° C. for 5 seconds, cooled, biaxially oriented film 190 μm, non-woven fabric A 10 μm biaxially oriented film composite sheet was obtained.
The measurement and evaluation results for the configuration and properties of the obtained biaxially oriented film composite sheet are as shown in Table 1. This biaxially oriented film composite sheet has high elongation at break and interfacial adhesion, and is processed. And excellent varnish impregnation properties.
(Example 2)
A biaxially oriented film composite sheet was obtained in the same manner as in Example 1 except that the blending ratio of the polyethylene terephthalate resin and PEI in Example 1 was changed to PET / PEI (90/10) (wt%).
The measurement and evaluation results for the configuration and properties of the obtained biaxially oriented film composite sheet are as shown in Table 1. This biaxially oriented film composite sheet has high elongation at break and interfacial adhesion, and is processed. And excellent varnish impregnation properties.
(Example 3)
A biaxially oriented film composite sheet was obtained in the same manner as in Example 1 except that the blending ratio of the polyethylene terephthalate resin and PEI in Example 1 was changed to PET / PEI (95/5) (% by weight).
The measurement and evaluation results for the configuration and properties of the obtained biaxially oriented film composite sheet are as shown in Table 1. This biaxially oriented film composite sheet has high elongation at break and interfacial adhesion, and is processed. And excellent varnish impregnation properties.
Example 4
Biaxially oriented film composite as in Example 1, except that the polyethylene naphthalate resin obtained in Reference Example 2 was used instead of PEI, and the blending ratio was changed to PET / PEN (70/30) (wt%). A sheet was obtained.
The measurement and evaluation results for the configuration and properties of the obtained biaxially oriented film composite sheet are as shown in Table 1. This biaxially oriented film composite sheet has high elongation at break and interfacial adhesion, and is processed. And excellent varnish impregnation properties.
(Example 5)
Instead of the unstretched PET / PEI film, the PPS pellets obtained in Reference Example 4 were used, melted at 320 ° C., extruded onto a drum from a T-shaped die onto a drum, and cooled and solidified to obtain an unstretched film. A biaxially oriented film composite sheet was obtained in the same manner as in Example 1 except that it was used.
The measurement and evaluation results for the configuration and properties of the obtained biaxially oriented film composite sheet are as shown in Table 1. This biaxially oriented film composite sheet has high elongation at break and interfacial adhesion, and is processed. And excellent varnish impregnation properties.
(Comparative Example 1)
A biaxially oriented film composite sheet was obtained in the same manner as in Example 1 except that the polyethylene terephthalate obtained in Reference Example 1 was used in place of PEI, that is, an unstretched film was produced only with a polyethylene terephthalate resin.

The measurement and evaluation results for the configuration and characteristics of the obtained biaxially oriented film composite sheet are as shown in Table 1. This biaxially oriented film composite sheet has low elongation at break and interfacial adhesion, and is processed. It was a decrease in sex.
(Comparative Example 2)
A biaxially oriented film composite sheet was obtained in the same manner as in Example 1 except that the blending ratio of the polyethylene terephthalate resin and PEI in Example 1 was changed to PET / PEI (99/1) (% by weight).

The measurement and evaluation results for the configuration and characteristics of the obtained biaxially oriented film composite sheet are as shown in Table 1. This biaxially oriented film composite sheet has low elongation at break and interfacial adhesion, and is processed. It was a decrease in sex.
(Comparative Example 3)
The unstretched PPS non-woven fabric is layered and supplied to a heated roll in the same manner as in Example 1 except that the blending ratio of polyethylene terephthalate resin and PEI in Example 1 is PET / PEI (60/40) (% by weight). Thermocompression bonding was performed at a temperature of 95 ° C. The laminated sheet thus obtained was biaxially oriented in the same manner as in Example 1 except that the laminated sheet was stretched in the longitudinal direction and the width direction with a silicone rubber stretching roll (pressure roll 1.5 N / cm) heated to 105 ° C. A film composite sheet was obtained.

The measurement and evaluation results for the configuration and properties of the obtained biaxially oriented film composite sheet are as shown in Table 1. This biaxially oriented film composite sheet has a low elongation at break and has decreased workability. It was a thing.
(Comparative Example 4)
Using the PPS pellets obtained in Reference Example 4, melted at 320 ° C., extruded on a drum from a T-shaped die onto a drum, cooled and solidified, and heated at 100 ° C. (a pressure roll) 1.5N / cm) is stretched 3.5 times in the longitudinal direction, further fed into a tenter type stretching machine, heated to 100 ° C. and stretched 3.5 times in the width direction, and then heat treated at 200 ° C. for 5 seconds, It heat-processed at 265 degreeC for 5 second, it cooled, and the biaxially-oriented PPS film of thickness 100 micrometers was obtained.
The obtained biaxially oriented PPS film and the PPS fiber sheet produced in Comparative Example 4 were thermocompression bonded with a 240 ° C. heated roll press. The pressing pressure was 10 kg / cm, and the thermocompression bonding speed was 1 m / min. The thickness of the obtained composite sheet is 100 μm biaxially oriented film and 90 μm fiber sheet, and the measurement and evaluation results for the configuration and properties of the obtained biaxially oriented film composite sheet are as shown in Table 1. The biaxially oriented film composite sheet had low elongation at break and interfacial adhesion, and had reduced workability.
(Comparative Example 5)
A biaxially oriented PPS film was prepared in the same manner as in Comparative Example 4 except that the thickness of the biaxially oriented PPS film in Comparative Example 4 was 75 μm.

  Further, an unstretched PPS film was obtained in the same manner as in Example 5 except that the thickness of the unstretched PPS film was changed to 50 μm in Example 5.

  The obtained biaxially oriented PPS film and unstretched PPS film were superposed in the order of biaxially oriented PPS film / unstretched PPS film / biaxially oriented PPS film, and thermocompression bonded with a heating roll press in the same manner as in Comparative Example 4 to obtain a composite A sheet was produced.

The measurement and evaluation results of the composition and properties of the obtained composite sheet are as shown in Table 1. This composite sheet has low elongation at break, low workability, and low varnish impregnation. It was a thing.
(Comparative Example 6)
An unstretched PPS nonwoven fabric was obtained in the same manner as in Reference Example 5 except that the basis weight of the unstretched PPS nonwoven fabric was 200 g / m ² .
This unstretched PPS nonwoven fabric was used, and the same procedure as in Example 5 was conducted except that the biaxially oriented film composite sheet was adjusted to have a thermoplastic resin film (PPS film) portion of 100 μm and a nonwoven fabric (PPS nonwoven fabric) portion of 100 μm. All biaxially oriented film composite sheets were obtained.
The measurement and evaluation results for the configuration and properties of the obtained biaxially oriented film composite sheet are as shown in Table 1. This biaxially oriented film composite sheet has a low elongation at break and has decreased workability. It was a thing.
(Comparative Example 7)
In Example 5, the film was stretched 4.2 times in the longitudinal direction, further fed into a tenter type stretching machine, and stretched in the width direction by 3.7 times (area stretch ratio: 15.54 times). A biaxially oriented film composite sheet was obtained.

  The measurement and evaluation results for the configuration and properties of the obtained biaxially oriented film composite sheet are as shown in Table 1. This biaxially oriented film composite sheet has a low elongation at break and has decreased workability. It was a thing.

  The biaxially oriented film composite sheet of the present invention is an electrically insulating material that balances various properties such as heat resistance, chemical resistance, low moisture absorption, interfacial adhesion, and varnish impregnation, and has excellent processability for motor insulation. Can be provided.

Claims (5)

A nonwoven fabric (B) layer made of polyarylene sulfide fibers is laminated on at least one surface of the biaxially oriented thermoplastic resin film (A) layer without using an adhesive, and the nonwoven fabric (B) layer is composed of fibers. The glass transition temperature T _gA of the thermoplastic resin constituting the fused A-like body and the glass transition temperature T _{gB of the} polyarylene sulfide constituting the B layer are represented by the following formula (1). the filled, it der breaking elongation of the composite sheet is 70% or more, the biaxially oriented film composite sheet, characterized in that is used for a motor for insulating paper.
−5 ° C. ≦ T _gB −T _gA ≦ 15 ° C. (1) 2. The biaxially oriented film according to claim 1, wherein a fusion point film extending between fibers is formed at at least a part of the fusion points in the network in the B layer. Composite sheet. The biaxially oriented film composite sheet according to claim 1 or 2, wherein the thermoplastic resin constituting the A layer is composed of either a composition containing polyester as a main component or polyarylene sulfide. The biaxially oriented film composite sheet according to claim 3, wherein the composition containing polyester as a main component contains 5 to 30% by weight of polyetherimide with respect to the total amount of the composition. A method for producing a biaxially oriented film composite sheet used for insulating paper for motors , which is an unstretched thermoplastic resin film satisfying the following formula (1) (the glass transition temperature of the resin constituting the film is T _gA A non-woven fabric made of polyarylene sulfide fibers (with the glass transition temperature of the resin constituting the non-woven fabric as _TgB ) is laminated and thermocompression bonded without using an adhesive, and then co-stretched in the biaxial direction. A method for producing a biaxially oriented film composite sheet.
−5 ° C. ≦ T _gB −T _gA ≦ 15 ° C. (1)