JPH0771842B2 - Laminated body and manufacturing method thereof - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a laminate. More specifically, it relates to a laminate of a non-oriented sheet containing poly-p-phenylene sulfide as a main component and a biaxially oriented poly-p-phenylene sulfide film, and a method for producing the laminate.

[Prior Art] As a conventional film, (1) a biaxially oriented poly-p-phenylene sulfide film (hereinafter sometimes abbreviated as a biaxially oriented PPS film) is used as an electrically insulating material. It is known from, for example, Japanese Laid-Open Publication No. 55-35459. Further, (2) non-oriented poly-p-phenylene sulfide sheet is also known from JP-A-56-34426 and JP-A-57-121052.

On the other hand, (3) stacking biaxially oriented PPS films with each other via an adhesive is also known from JP-A-6-241142. Further, (4) a laminated film of a biaxially oriented PPS film and a biaxially oriented polyester film (Japanese Patent Laid-Open No. 62-2924).
31), (5) a laminate of a biaxially oriented PPS film and a fiber sheet of an aromatic polymer (JP-A-60-63158), (6) biaxially oriented PPS film and tetrafluoride. Ethylene-6
A laminated film with a fluorinated propylene copolymer film (Japanese Patent Laid-Open No. 62-292432) is also known.

[Problems to be Solved by the Invention] However, the above-mentioned film, sheet, laminated film and laminated body have the following problems.

That is, the film of item (1) described in the section of the prior art has poor impact resistance and tear strength. For example, when it is used as a slot liner or a wedge of a motor, the film may tear or the film may be damaged. There was a problem of lamination.

The non-oriented sheet of the item (2) has a high tear strength, but has a low tensile elongation, and when exposed to a temperature near the melting point, the strength sharply decreases and the shape retention property deteriorates remarkably. .

The laminated film of the item (3) has improved impact resistance and tear strength as compared with the film of the item (1), but is insufficient.
Further, since the adhesive is present, there is a risk of deteriorating excellent properties such as heat resistance and chemical resistance of the biaxially oriented PPS film.

The laminated film of the item (4) cannot fully utilize the excellent characteristics of the biaxially oriented PPS film because the laminated biaxially stretched polyester film has poor heat resistance, chemical resistance and wet heat resistance.

The laminate of item (5) has excellent heat resistance and impact resistance,
Since they are laminated with the adhesive interposed, the adhesive has poor heat resistance and chemical resistance, and the characteristics of the laminate are deteriorated. Further, since the fiber sheet of the laminate has a very high hygroscopicity, the dimensional change of the laminate under heat and humidity becomes large. In addition, there is a limitation in application as an insulating material for motors and the like (for example, hermetic motors for refrigerators) that require precision because loosening and chips of the fiber sheet of the laminated body occur due to slit processing and the like.

Further, the laminated film of the item (6) has excellent heat resistance and chemical resistance, and since the laminated film is laminated without the interposition of an adhesive, there is no fear that the adhesive will adversely affect the laminated film. Also, the tear strength of the laminated film is high. However, in order to manufacture the laminated film, in addition to the fact that each film requires a special surface treatment and the adhesive force at the laminating interface of the laminated film is poor, if a sudden impact force is applied to a part of the film. There is a problem that the biaxially oriented PPS film is peeled off and split.

The present invention solves the above problems, and laminates PPS alone, which has well-balanced properties such as heat resistance, chemical resistance, flame resistance, impact resistance, moist heat resistance and workability without interposing an adhesive. Intended to provide the body.

[Means for Solving the Problems] The present invention provides a laminate in which a biaxially oriented polyphenylene sulfide layer (B) is laminated on at least one side of a non-oriented polyphenylene sulfide layer (A) without an adhesive. The present invention relates to a manufacturing method thereof.

In the present invention, poly-p-phenylene sulfide (hereinafter sometimes abbreviated as PPS) means a repeating unit of 70
Molar% or more (preferably 85 mol% or more) is the structural formula A polymer comprising a structural unit represented by Related ingredients
If it is less than 70 mol%, the crystallinity of the polymer, the heat transition temperature, etc. are lowered, and the heat resistance, dimensional stability, mechanical properties, etc., which are the features of the film made of the resin composition containing PPS as a main component, are impaired.

If the repeating unit is less than 30 mol%, preferably less than 15 mol%, the unit containing a copolymerizable sulfide bond may be contained. The method of copolymerizing the polymer may be random or block type.

In the present invention, the resin composition containing poly-p-phenylene sulfide as a main component (hereinafter sometimes abbreviated as PPS-based composition) means poly-p-phenylene sulfide.
A composition containing 60% by weight or more.

When the content of PPS is less than 60% by weight, mechanical properties such as tear strength and heat resistance of a non-oriented sheet made of the composition are impaired.

The remaining less than 40% by weight of the composition is a polymer other than PPS,
Additives such as inorganic or organic fillers, lubricants and colorants may be included.

The melt viscosity of the resin composition is 300 ° C. at a shear rate of 200 1
The range of 700 to 20000 poise is preferable in terms of sheet formability under / sec.

The non-oriented sheet (may be abbreviated as PPS-NO hereinafter) referred to in the present invention is a general term for films, sheets, and plates having a thickness of 1 mm or less formed by melt-molding the above PPS-based composition. The non-oriented and unstretched ones.

Biaxially oriented poly-p-phenylene sulfide film in the present invention (hereinafter sometimes abbreviated as PPS-BO).
Is a film obtained by melt-molding a resin composition containing 90% by weight or more of poly-p-phenylene sulfide into a sheet, biaxially stretching and heat-treating. 90 PPS content
If it is less than 10% by weight, the crystallinity of the composition, the degree of thermal transition, etc. are lowered, and the heat resistance, dimensional stability, mechanical properties, etc., which are the features of the film made of the composition, are impaired.

The remaining less than 10% by weight of the composition is a polymer other than PPS,
Additives such as inorganic or organic fillers, lubricants, colorants, and UV absorbers can be included.

The melt viscosity of the resin composition is 300 ° C. at a shear rate of 200 1
500-12,000 poise (more preferably 700
The range of up to 10,000 poise) is preferable from the viewpoint of film formability.

The melt viscosity of the resin composition is the biaxial orientation finally obtained.
Equivalent to the melt viscosity of PPS film.

The thickness of the film is preferably in the range of 3 to 300 μm.

The present invention is a laminate of PPS-NO and PPS-BO without an adhesive. Prior to lamination, the PPS-NO may be heat-treated or oxidatively crosslinked. In addition, PPS-NO and PPS-
The present invention also includes corona discharge treatment or plasma treatment on the surface of the BO.

A first aspect of a possible laminate construction of the laminate of the invention is
It has a two-layer structure in which PPS-NO (A) and PPS-BO (B) are laminated, and heat resistance when heat is applied when the thickness ratio A / B of A and B is 0.1 to 10. It is preferable in terms of the balance between the properties, shape retention and impact resistance. The total thickness of the stack is 20-
The range of 700 μm is preferred.

A second aspect of a possible laminate construction of the laminate of the invention is
PPS-BO (A), PPS-NO (B) and PPS-BO (A ') are laminated in this order, and the thicknesses of A, A'and B are expressed by the formula 0.1≤ (A + A') / B≤. It is preferable to satisfy 10 from the viewpoint of the balance between heat resistance when heat is applied, shape retention and impact resistance. Also A and A '
The thickness ratio A / A ′ of 0.5 to 2.0 is preferable in terms of workability during processing. Furthermore, the thickness of the entire laminate is preferably in the range of 30 to 1000 μm.

The laminate of the present invention, without providing an adhesive layer,
PPS-NO and PPS-BO are joined by fusion.

Next, a method for manufacturing the laminate of the present invention will be described.

The PPS used in the present invention is obtained by reacting alkali sulfide and paradihalobenzene in a polar solvent at high temperature and high pressure. In particular, sodium sulfide and paradichlorobenzene are added to N
It is preferred to react in an amide high boiling polar solvent such as -methylpyrrolidone. In this case, in order to adjust the degree of polymerization, it is most preferable to add a so-called polymerization aid such as caustic alkali or alkali metal carboxylic acid and react at 230 to 280 ° C. The pressure in the polymerization system and the polymerization time are appropriately determined depending on the kind and amount of the auxiliary agent used, the desired degree of polymerization, and the like. The obtained powdery or granular polymer is washed with water and / or a solvent to separate a by-product salt, a polymerization aid, an unreacted monomer and the like.

To form this polymer into a non-oriented sheet, it is supplied to a melt extruder typified by an extruder, heated to a temperature equal to or higher than the melting point of the polymer, melted, and continuously extruded from a slit-shaped die, It is obtained by rapid cooling to a temperature below the glass transition point of the film.

For the biaxially oriented PPS film, the above sheet is biaxially stretched and heat treated by a known method.

Stretching is performed at 90 to 110 ° C. in the longitudinal direction and the width direction in the range of 3.0 to 4.5 times. The heat treatment is performed in the range of 180 ° C. to the melting point for 1 to 60 seconds under a constant length or a restricted shrinkage of 15% or less. Further, it may be relaxed in one or two directions to improve the thermal dimensional stability of the film.

Next, the method of laminating PPS-NO and PPS-BO can be carried out by thermocompression bonding both at high temperature and high pressure, or by directly bonding PPS on the biaxially oriented film.
A method of melt-extruding and laminating can be used.

In the former method, the temperature is 180-270 ℃, the pressure is 1-20kg.
Roll press, hot plate press, etc. under the condition of / cm ² .

In the case of laminating into three layers, a bilayer body is first prepared under the above conditions, and a biaxially oriented PPS film can be further laminated on the PPS-NO side of the bilayer body, or three layers can be laminated simultaneously. .

On the other hand, when the PPS is directly melt-extruded and laminated on the biaxially oriented PPS film, the PPS is supplied to an extruder, heated to a temperature equal to or higher than the melting point, continuously extruded from a slit-shaped die, and provided below. Biaxially oriented PP on press roll
Laminate while pressing on S film.

In the case of laminating into three layers, PPS can be extruded and laminated between two layers of biaxially oriented PPS films under the above conditions. As another method, another layer of biaxially oriented PPS film can be laminated by thermocompression bonding to the unstretched PPS side of the two-layer laminate obtained by the above method.

EFFECTS OF THE INVENTION Since the laminate of the present invention is configured as described above, heat resistance (long-term heat resistance, high-temperature short-term heat resistance), moist heat resistance, impact resistance, and flame retardancy, which are important properties particularly as an electrical insulating material. This material has a high level of balance of properties such as properties.

Further, since the laminate of the present invention does not have an adhesive interposed, deterioration of the adhesive does not deteriorate the characteristics of the laminate.

[Use] The laminate of the present invention is most suitable for the insulation properties of motors and transformers, which require heat resistance, moist heat resistance and the like. For example, it can be used as an insulating material for various motors such as hermetic motors, servo motors, motors for vehicles, etc. used in a state of being immersed in refrigerating machine oil, various transformers such as gas transformers, oil transformers, mold transformers, and generators.

Moreover, since it is excellent in radiation resistance and low temperature characteristics, it is also most suitable as a coating material for an electric insulating material or a superconducting material of a device requiring radiation resistance such as a nuclear power plant.

Also, covering materials for electric wires, printed circuit boards, belts and interior materials,
It is also suitable for diaphragms and acoustic diaphragms.

Further, the laminate of the present invention may be laminated with another film, a heat-resistant fiber sheet, a metal, or may be coated with another resin.

Next, the method of measuring the characteristics and the criteria for evaluation used in the description of the present invention will be described.

(1) Heat resistance 2000 at 180 ° C in the initial and hot air oven of the sample film
Tensile strength after time aging is measured according to the ASTM-D-638-72 method. Heat resistance is ○ if the strength after aging is 70% or more of the initial value, △ is 10 to less than 70%, and less than 10%. Was designated as x.

(2) Tear strength Measured according to JIS-P8116-1960 and expressed in g / mm.

(3) Impact resistance The sample is cut out to a width of 20 mm and a length of 100 mm, looped in the length direction, and the end is fixed and 20 cm from the widthwise tip of the sample.
From the height of, the weight of 1 kg was dropped and ranked by the following.

◯: The sample is not damaged at all.

Δ: A part of the tip is torn.

X: The tip portion is largely delaminated or largely torn.

(4) Heat resistance at high temperature After a sample with a width of 10 mm and a length of 50 mm is floated on solder of 260 ° C ± 2 ° C for 10 seconds, both ends of the sample are pinched with tweezers inside the solder and pulled by hand. The heat resistance was judged by.

◯: Does not extend even when pulled.

Δ: A little stretched when pulled.

X: When stretched, it has a large elongation and breaks.

(5) Moisture and heat resistance Put the sample in a 200cc autoclave, put a small amount of water in it, and seal it. Measure the tensile elongation after aging at 120 ° C for 100 hours according to the ASTM-D-638-72 method. If the elongation is 70% or more of the initial value, the resistance to moisture and heat is ○, 10
Less than 70% was rated as Δ and less than 10% was rated as x.

(6) Flame Retardancy A sample was cut into a width of 20 mm, the tip was exposed to a flame, and the combustion state of the sample when the sample was moved away from the flame was evaluated according to the following criteria.

○: The fire goes out immediately.

Δ: Burns for a while and then disappears.

X: Fire does not go out.

(7) Adhesive strength A 90 degree peel was performed using a shopper. The width of the sample was 10 mm and the peeling speed was 200 mm / min.

(8) Breaking elongation Measured according to the ASTM-D-638-72 method.

[Examples] Next, the present invention will be described in detail with reference to Examples.

Example 1 (1) Preparation of PPS unstretched sheet used in the present invention In an autoclave, 32.6 kg of sodium sulfide (250 mol,
(Including 40% by weight of water of crystallization), 100 g of sodium hydroxide, 36.1 kg (250 mol) of sodium benzoate, and N-methyl-2.
-Pyrrolidone (hereinafter sometimes referred to as NMP) 79.2 kg
Was charged and dehydrated at 205 ° C., then 37.5 kg (255 mol) of 1.4 dichlorobenzene and 20.0 kg of NMP were added, and the reaction was carried out at 265 ° C. for 4 hours. The reaction product is washed with water, dried and p-
Poly-p-phenylene sulfide 2 consisting of 100 mol% phenylene sulfide unit and having a melt viscosity of 3100 poise
1.1 kg (yield 78%) was obtained.

To this composition, 0.1 wt.
%, Calcium stearate 0.05% by weight, melted at 310 ° C with a 40 mm diameter extruder, filtered with a 95% cut hole diameter 10 μm filter using metal fibers, and then a linear lip with a length of 400 mm and a gap of 0.5 mm Was extruded from a T-die having a surface and cast on a metal drum whose surface was kept at 25 ° C. to obtain a 100 μm-thick non-oriented sheet. (P
PS-NO-1. (2) Adjustment of PPS-BO PP made of "Torelina" type 3000 manufactured by Toray Industries, Inc. with a thickness of 50 μm
S-BO was used. (It is referred to as PPS-BO-1.) (3) Preparation of laminated body PPS-NO-1 and PPS-BO-1 at a temperature of 230 ° C and a pressure of 10 kg / cm ²
Using the press roll, the three layers were laminated and laminated so as to have a structure of PPS-BO / PPS-NO / PPS-BO.

(It is referred to as a laminated body-1.) Example 2 (1) Preparation of laminated body PPS-NO-1 used in Example 1 and "Torelina" type 3000 manufactured by Toray Industries, Inc., type PPS-BO having a thickness of 100 µm ( PPS-BO-2
And ) Was laminated under the conditions of Example 1, and PPS-NO /
A bilayer of PPS-BO was prepared. (Laminated body-2.) Comparative Examples 1 to 4 Under the conditions of Example 1, an unstretched sheet having a thickness of 150 μm was prepared. Further, the sheet was roll heat-treated at a temperature of 230 ° C. for 5 seconds. (PPS-NO-2, Comparative Example 1) An unstretched sheet having a thickness of 2.5 mm was prepared under the same conditions by setting the distance between the linear lips to 1.5 mm by the method of Example 1 and further comprising this group of rolls. Temperature of 98 by vertical stretching machine
℃, stretching speed 30000% / min 3.9 times longitudinal stretching, then using a tenter, temperature 100 ℃, stretching speed 1000% / min 3.5 times transverse stretching, further in the subsequent heat treatment chamber in the same tenter 270 ℃
And heat-treated for 10 seconds to obtain a PPS-BO having a thickness of 150 μm.
(Comparative column 2) PPS-BO-2 used in Example 2 was subjected to corona discharge treatment on one surface thereof, and a two-layer body of PPS-BO was prepared through the following adhesive. . (Laminated film-1, Comparative example 3) Adhesive: urethane adhesive, "Adcoat" 76P1 The mixing ratio of the main agent and the curing agent of the above adhesive is the main agent / curing agent =
It was adjusted to 100/8 and adjusted to a solid content concentration of 32 wt% with ethyl acetate, and applied on the corona discharge treated surface of PPS-BO-3 by the gravure roll method. The drying condition was 80 ° C. for 3 minutes, and the coating thickness was adjusted to 8 μm after drying. Then, the other PPS-BO-2 was pasted with a roll laminator. The bonding conditions were a temperature of 80 ° C. and a pressure of 3 kg / cm ² . Further, the laminated film was cured at a temperature of 60 ° C. for 50 hours.

25 μm of “Torelina” type 3000 manufactured by Toray Industries, Inc. (PPS-B
O-4. ) And 100 μ of “Lumirror” S10 manufactured by Toray Industries, Inc.
m (referred to as PET-BO-1), PPS-BO-4 on one side and PET-BO-1 on both sides by corona treatment under the condition of 6000 J / m ² through the adhesive below. PPS-BO-4 / PET-BO-1 / PP
S-BO-4 was laminated in this order. (Laminated film-2. Comparative example 4) Adhesive: "Chemit epoxy" TE5920 (manufactured by Toray Industries, Inc.)
Solid content concentration 30 wt% Adhesive formulation: Agent A / Agent B = 15/100 The above adhesive was applied by the gravure roll method, and the drying condition was 100 ° C for 3 minutes, and the adhesive application thickness was dry. It was adjusted to 8 μm later. In addition, the lamination conditions are temperature 12
The temperature was 0 ° C. and the pressure was 3 kg / cm ² . The curing condition of the adhesive of the laminated film was 150 ° C. for 1 hour.

Evaluation Table 1 shows the evaluation results of the samples obtained in Examples 1 and 2 and Comparative Examples 1 to 4.

It can be seen that the laminate of the present invention has significantly improved impact resistance and tear strength, which were the conventional problems, without lowering the heat resistance, wet heat resistance and flame retardancy of PPS-BO. . Further, heat resistance at high temperature and elongation at break, which were problems of PPS-NO, are improved.

Further, although the laminated film of PPS-BOs has improved tear strength as compared with PPS-BO alone due to the cushioning action of the adhesive, it does not reach a practical level and has poor resistance to a sudden impact force. Further, since the laminate has an adhesive agent interposed therein, heat deterioration of the adhesive agent adversely affects properties such as heat resistance and flame retardancy of PPS-BO.

Further, the laminated film of PPS-BO and PET-BO is rich in impact resistance and tear strength, but since the PET film of the central layer is poor in heat resistance, moist heat resistance and flame retardancy, the characteristics of the laminated film, especially moisture resistance. There is a problem with heat resistance and flame retardancy.

Example 3 In the same manner as in Example 1, a laminated body of three layers having the thickness constitution of each layer as shown in Table 2 was prepared. In addition, PPS-B
"Torelina" manufactured by Toray Industries, Inc. was used for all O. Table 2 shows the evaluation results of these laminates.

When the thickness composition ratio (A + A ') / B is small, the rupture elongation and heat resistance at high temperatures tend to decrease, and conversely, when the composition ratio is large, the tear strength tends to be low and the impact resistance tends to decrease. It is in.

Example 4 Using PPS-NO-1 and PPS-BO-1 of Example 1, the lamination temperature and pressure were changed under the conditions of Example 1, and the lamination state was observed. The results are shown in Table 3. Stacking temperature is 180 ℃
If it is less than 270 ° C., it does not adhere, and if it exceeds 270 ° C., the flatness of the laminate suddenly deteriorates, and it becomes difficult to control the thickness and uneven thickness of the laminate.

On the other hand, if the pressure is less than 1.0 kg / cm ² , the adhesion will not occur even if the lamination temperature is increased, and if it exceeds 20 kg / cm ² , the flatness will be suddenly deteriorated or the PPS-NO in the center layer will be broken. Therefore, it becomes difficult to control the thickness and thickness unevenness of the laminate.

Example 5 PPS-NO-1 and PPS-BO-1 of Example 1 were overlapped and
The layers were laminated under the conditions of Example 1. Furthermore, PPS-NO-of the two-layer body
PPS-BO-1 was laminated on the first side under the conditions of a temperature of 250 ° C. and a pressure of 10 kg / cm ² (laminate-3), and the difference in the production method from the laminate-1 of Example 1 was compared.

Table 4 shows the evaluation results of the laminate-3. It can be seen that the physical properties are the same as those of the laminates 1 and 2 in Table 1. That is, the production of a three-layer laminate of PPS-BO / PPS-NO / PPS-BO is
The above three layers can be laminated and laminated at the same time, or a two-layer body of PPS-NO / PPS-BO can be prepared in advance, and subsequently PPS-BO can be laminated on the PPS-NO side of the laminate. You can also do it.

Example 6 The PPS polymer used in Example 1 was melted at 310 ° C. in a 30 mm diameter extruder and extruded from a T-die having straight lips with a length of 200 mm and a spacing of 0.5 mm.

On the other hand, a metal press roll having a surface temperature kept at 25 ° C. was provided immediately below the T die, and the PPS-BO-2 used in Example 2 was used.
The polymer was run while pressing at a speed of m / min, and the above polymers were continuously laminated so that the laminated thickness was 100 μm. The distance between the T-die and PPS-BO-2 is 10 mm, and the pressing pressure is 2 kg.
/ cm ² . The obtained laminated body is referred to as laminated body-4.

Example 7 In the same manner as in Example 6, a PPS polymer was extruded between two layers of PPS-BO-1 to prepare a three-layer laminate of PPS-BO / PPS-NO / PPS-BO. The stacking conditions are those of Example 5.
The obtained laminated body is referred to as laminated body-5.

Example 8 A PPS polymer was extruded and laminated on PPS-BO-1 under the conditions of Example 6 to form a two-layer body. Furthermore, the PPS of the laminate
Another layer of PPS-BO-1 was laminated on the —NO side by thermocompression bonding under the conditions of a temperature of 230 ° C. and a pressure of 10 kg / cm ² . Obtained 3
The layer stack is referred to as Stack-6.

Evaluation As a result of evaluating the laminates 4 to 6 prepared in Examples 6 to 8, the same physical property values as those of the laminates 1 and 2 shown in Table 1 were obtained, and all of the objects of the present invention were achieved. It was

Comparative Example 5 PPS-BO / PPS-NO / PPS-BO was prepared by using the PPS-BO-1 and PPS-NO-1 used in Example 1 through the adhesive used in Comparative Example 3.
A three-layer laminate was prepared in this order. The lamination conditions are the same as those in Comparative Example 3. (Laminate-7) Table 5 shows the evaluation results of the laminate-7.

The heat deterioration of the adhesive affects the heat resistance of the laminate. 180
Comparative Example 3 shows the retention of strength after aging at 2000C for 2000 hours.
Compared with the laminated film-1 of
The laminate-7 was as low as 40% as compared with 60%.

Claims (6)

[Claims] 1. A laminate in which a biaxially oriented polyphenylene sulfide layer (B) is laminated on at least one side of a non-oriented polyphenylene sulfide layer (A) without an adhesive. 2. A non-oriented polyphenylene sulfide sheet and a biaxially oriented polyphenylene sulfide film are superposed and thermocompression bonded under the conditions of a temperature of 180 ° C. to 270 ° C. and a pressure of 1 to 20 kg / cm ^2. Claims No. 1
Item 2. A method for producing a two-layer laminate according to item. 3. A method for producing a two-layer laminate according to claim 1, wherein the polyphenylene sulfide is melted and extruded from a slit-shaped die onto a biaxially oriented polyphenylene sulfide film for integration. Method. 4. The three layers according to claim 1, wherein the polyphenylene sulfide is melted and extruded from a slit-shaped die between two biaxially oriented polyphenylene sulfide films to integrate them. Method for manufacturing laminated body. 5. Following the method according to claim 2 or 3, a biaxially oriented polyphenylene sulfide film is superposed on the A layer side of the two-layer laminate, and the temperature is changed.
The method for producing a three-layer laminate according to claim 1, wherein thermocompression bonding is performed under the conditions of 180 ° C. to 270 ° C. and a pressure of 1 to 20 kg / cm ² . 6. A biaxially oriented polyphenylene sulfide film, a non-oriented polyphenylene sulfide sheet and a biaxially oriented polyphenylene sulfide film are laminated in this order, and the temperature is 180 ° C. to 270 ° C. and the pressure is 1 to 20 kg / cm ^2.
The method for producing a three-layer laminate according to claim 1, wherein the thermocompression bonding is performed under the conditions described in (1) above.