Long laminated base material, long sheet roll, and methods for producing long laminated base material and long sheet roll

Abstract

The long laminated substrate is provided with a substrate having a predetermined thickness and two polymer layers respectively provided on both surfaces of the substrate, the two polymer layers contain a tetrafluoroethylene polymer and each have a predetermined thickness, and the value of the root mean square slope Sdq measured on the surface opposite the substrate is 5 [mu] m / mm or less. The long sheet roll has a cylindrical winding core and a long laminated base material wound around the outer peripheral surface of the winding core, the long laminated base material is provided with a base material having a predetermined thickness and two polymer layers respectively provided on both surfaces of the base material, and the two polymer layers contain a tetrafluoroethylene-based polymer and each have a predetermined thickness. The total thickness of the two polymer layers is a predetermined time of the thickness of the base material, the thickness of one of the two polymer layers is a predetermined time of the thickness of the other polymer layer, and the value of the product of the curvature of the outer diameter of the winding core and the total thickness of the long laminated base material is less than 0.0015.

Description

Technical Field

[0001] The present disclosure relates to a long laminate substrate, a long sheet roll, and methods for producing the same. Background Art

[0002] Tetrafluoroethylene polymers have excellent physical properties such as mold release, electrical insulation, water and oil repellency, chemical resistance, weather resistance, and heat resistance. Tetrafluoroethylene polymers are used to form various molded products such as impregnated substrates, supported substrates, and layered substrates.

[0003] For example, Patent Document 1 discloses a multilayer film formed by laminating tetrafluoroethylene-based polymer films of the same thickness on both surfaces of a polyimide substrate film.

[0004] Furthermore, Patent Document 2 describes a multilayer film having fluororesin layers of the same thickness formed by continuously coating a tetrafluoroethylene-based polymer on both surfaces of a polyimide substrate film.

[0005] Prior art literature

[0006] Patent Literature

[0007] Patent Document 1: International Publication No. 2010 / 084867

[0008] Patent Document 2: International Publication No. 2021 / 200630 Summary of the invention

[0009] Technical problem to be solved by the invention

[0010] The long laminated substrate as a laminated body in which polymer layers containing a tetrafluoroethylene-based polymer are provided on both surfaces of a substrate can have both the physical properties of the tetrafluoroethylene-based polymer and the physical properties of the substrate.

[0011] However, when the long laminated substrate is unwound after being wound around a winding core to form a roll-shaped substrate, the long laminated substrate may sometimes have undulations. Furthermore, when a metal foil is pressed onto the surface of the undulating long laminated substrate to produce a metal-clad laminate, the metal foil tends to be easily peeled off due to the undulations of the long laminated substrate.

[0012] In addition, for a laminated substrate obtained by laminating tetrafluoroethylene polymer layers on both sides of a substrate, the physical properties of the entire laminated substrate can be arbitrarily and easily controlled by selecting the type and shape (thickness, etc.) of the substrate and the type and shape (thickness, etc.) of the tetrafluoroethylene polymer. Therefore, the above-mentioned laminated substrate can be used as a material for a printed wiring substrate, etc.

[0013] However, the inventors have found that in a long sheet roll obtained by winding the long laminated substrate, i.e., the long laminated substrate, around a winding core, when the long laminated substrate is unwound to form a metal-clad laminate, wrinkles may occur in the metal foil. When wrinkles occur in the metal foil, it is easy to cause obstacles (deterioration of yield, reduction of product quality, etc.) in the manufacture of printed wiring boards, etc.

[0014] An object of the present invention is to provide a long-strip laminated substrate and a method for manufacturing the same, wherein the peeling of the metal foil caused by the undulation of the long-strip laminated substrate can be suppressed even when the long-strip laminated substrate is wound around a core to form a roll-shaped substrate and then unwound for use in manufacturing a metal-clad laminate.

[0015] Another object of the present disclosure is to provide a long sheet roll capable of suppressing wrinkles in the metal foil when unwinding a long laminated substrate to produce a metal-clad laminate, and a method for producing the same.

[0016] Technical solutions adopted to solve technical problems

[0017] The present disclosure includes the following aspects.

[0018] <a1>A long laminated substrate comprises a substrate with a thickness of 12 to 50 μm and two polymer layers respectively arranged on both sides of the substrate, wherein the two polymer layers contain a tetrafluoroethylene polymer and each has a thickness of 12 to 40 μm, and the value of the root mean square slope Sdq measured on the surface opposite to the substrate in accordance with ISO25178-2:2012 is less than 5 μm / mm.

[0019] <a2>like <a1>The long laminated substrate comprises at least one selected from polyimide, liquid crystal polyester and polytetrafluoroethylene.

[0020] <a3>like <a1>or <a2>In the long laminated substrate, the two polymer layers are layers of a sintered body containing particles of the tetrafluoroethylene-based polymer.

[0021] <a4>like <a1> ～ <a3>The long laminated substrate according to any one of the preceding claims, wherein the total thickness of the two polymer layers is 1.8 to 3.0 times the thickness of the substrate.

[0022] <a5>like <a1> ～ <a4>The long laminated substrate described in any one of the above-mentioned two polymer layers has a thickness of one polymer layer that is 0.9 to 1.1 times the thickness of the other polymer layer.

[0023] <a6>like <a1> ～ <a5>The long laminated substrate according to any one of the preceding claims, wherein the tetrafluoroethylene-based polymer is a tetrafluoroethylene-based polymer having a melting point of 260 to 320°C.

[0024] <a7>like <a1> ～ <a6>The long laminated substrate according to any one of the preceding claims, wherein the tetrafluoroethylene-based polymer has an oxygen-containing polar group.

[0025] <a8>like <a1> ～ <a7>The long laminated substrate described above is a roll-shaped substrate wound around a core.

[0026] <a9>A method for manufacturing a long laminated substrate comprises: conveying the substrate while bringing the second surface of a long substrate having a thickness of 12 to 50 μm into contact with the outer peripheral surface of a backing roller having a ten-point average roughness Rzjis of 0.5 to 10 μm at a contact surface pressure of 100 to 3000 kPa, coating a composition containing particles of a tetrafluoroethylene polymer and a liquid dispersion medium on the first surface of the substrate and performing a heat treatment, thereby forming a first layer on the first surface; and conveying the substrate while bringing the first layer into contact with the outer peripheral surface of the backing roller at a contact surface pressure of 100 to 3000 kPa, coating the composition on the second surface and performing a heat treatment, thereby forming a second layer on the second surface, thereby obtaining a long laminated substrate comprising the substrate, a first polymer layer comprising the tetrafluoroethylene polymer and having a thickness of 12 to 40 μm, and a second polymer layer comprising the tetrafluoroethylene polymer and having a thickness of 12 to 40 μm.

[0027] <a10>like <a9>In the manufacturing method, the ten-point average roughness Rzjis of the outer peripheral surface of the backing roller is 0.5 to 8 μm.

[0028] <a11>like <a9>or <a10>The manufacturing method, wherein the contact surface pressure is 250 to 2000 kPa.

[0029] <a12>like <a9> ～ <a11>The production method described in any one of the above aspects, wherein the surface tension of the liquid dispersion medium is 20 to 30 mN / m.

[0030] <a13>like <a9> ～ <a12>The method for producing a long laminated substrate as described in any one of the above, wherein the substrate comprises at least one selected from the group consisting of polyimide, liquid crystal polyester and polytetrafluoroethylene.

[0031] <a14>like <a9> ～ <a13>In any one of the above-mentioned long laminated substrates, the total thickness of the first polymer layer and the second polymer layer is 1.8 to 13 times the thickness of the substrate.

[0032] <a15>like <a9> ～ <a14>The manufacturing method described in any one of the above, wherein the thickness of the first polymer layer is 0.9 to 1.1 times the thickness of the second polymer layer.

[0033] <a16>like <a9> ～ <a15>The production method according to any one of the preceding claims, wherein the tetrafluoroethylene polymer particles contain a tetrafluoroethylene polymer having a melting point of 260° C. or higher.

[0034] <a17>like <a9> ～ <a16>The production method according to any one of the preceding claims, wherein the tetrafluoroethylene polymer particles include a tetrafluoroethylene polymer having an oxygen-containing polar group.

[0035] <a18>like <a9> ～ <a17>The manufacturing method described in any one of the above aspects further comprises winding the long laminated substrate on a winding core to form a rolled substrate.

[0036] In addition, the present disclosure also includes the following aspects.

[0037] <b1>A long sheet roll comprises a cylindrical winding core and a long laminated substrate wound around the outer peripheral surface of the winding core.

[0038] The long laminated substrate comprises a substrate having a thickness of 12 to 50 μm and two polymer layers respectively arranged on both sides of the substrate, the two polymer layers contain a tetrafluoroethylene polymer and each has a thickness of 12 to 40 μm, the total thickness of the two polymer layers is 1.8 to 3.0 times the thickness of the substrate, the thickness of one of the two polymer layers is 0.9 to 1.1 times the thickness of the other polymer layer, and the curvature Cmm of the outer diameter of the winding core -1 The value of the product C×T of the total thickness Tmm of the long laminated base material is less than 0.0015.

[0039] <b2>like <b1>The long sheet roll, wherein the curvature Cmm of the outer diameter of the roll core -1 0.009~0.037mm -1 .

[0040] <b3>like <b1>or <b2>The long sheet roll, wherein the length of the long side direction of the long laminated substrate is more than 200 m.

[0041] <b4>like <b1> ～ <b3>The long sheet roll described in any one of the above aspects, wherein the width of the long laminated substrate in the short side direction is 500 to 1250 mm.

[0042] <b5>like <b1> ～ <b4>The long sheet roll described in any one of the above aspects, wherein the two polymer layers are layers of a sintered body containing particles of the tetrafluoroethylene-based polymer.

[0043] <b6>like <b1> ～ <b5>The long sheet roll described in any one of the preceding claims, wherein the tetrafluoroethylene-based polymer is a tetrafluoroethylene-based polymer having a melting point of 260 to 320°C.

[0044] <b7>like <b1> ～ <b6>The long sheet roll described in any one of the preceding claims, wherein when the long laminated substrate is unwound by 500 mm and the laminated substrate sheet cut out is placed on a horizontal surface, the height of the laminated substrate sheet floating from the horizontal surface is 1 cm or less.

[0045] <b8>A method for manufacturing a long sheet roll, comprising:

[0046] A long laminated substrate is prepared, wherein the long laminated substrate comprises a substrate having a thickness of 12 to 50 μm and two polymer layers respectively arranged on both sides of the substrate, the two polymer layers contain a tetrafluoroethylene polymer and each has a thickness of 12 to 40 μm, the total thickness of the two polymer layers is 1.8 to 3.0 times the thickness of the substrate, and the thickness of one of the two polymer layers is 0.9 to 1.1 times the thickness of the other polymer layer; and the long laminated substrate is wound on the outer peripheral surface of a cylindrical winding core, and the curvature Cmm of the outer diameter of the winding core -1 The value of the product C×T of the total thickness Tmm of the long laminated base material is less than 0.0015.

[0047] <b9>like <b8>In the production method, the winding stress when the long-length laminated substrate is wound around the outer peripheral surface of the winding core is 1 to 3 MPa.

[0048] <b10>like <b8>or <b9>The manufacturing method, wherein the curvature Cmm of the outer diameter of the winding core -1 0.009~0.037mm -1 .

[0049] <b11>like <b8> ～ <b10>The production method described in any one of the above-mentioned aspects, wherein the length of the long laminated substrate in the longitudinal direction is 200 m or more.

[0050] <b12>like <b8> ～ <b11>The manufacturing method described in any one of claims , wherein the width of the long laminated substrate in the short side direction is 500 to 1250 mm.

[0051] <b13>like <b8> ～ <b12>The production method according to any one of the preceding claims, wherein the two polymer layers are obtained by applying a composition containing the tetrafluoroethylene polymer particles and a liquid dispersion medium on both surfaces of the substrate and subjecting the resulting composition to heat treatment.

[0052] <b14>like <b8> ～ <b13>The production method according to any one of the preceding claims, wherein the tetrafluoroethylene polymer has a melting point of 260 to 320°C.

[0053] Effects of the Invention

[0054] According to the present disclosure, a long laminated substrate and a method for manufacturing the same can be provided, wherein the peeling of the metal foil caused by the undulation of the long laminated substrate can be suppressed even when the long laminated substrate is wound around a core to form a roll-shaped substrate and then unwound for use in manufacturing a metal-clad laminate.

[0055] Furthermore, according to the present disclosure, it is possible to provide a long sheet roll and a method for producing the same, wherein the long sheet roll can suppress wrinkles in the metal foil when unwinding the long laminated substrate to produce a metal-clad laminate. BRIEF DESCRIPTION OF THE DRAWINGS

[0056] Figure 1 This is a schematic cross-sectional view showing the layer structure of a long laminated base material according to one embodiment.

[0057] Figure 2 This is a schematic diagram schematically showing a coating section of an apparatus used in a method for producing a long laminated substrate according to one embodiment.

[0058] Figure 3 This is a perspective view schematically showing a long sheet roll according to one embodiment.

[0059] Figure 4 It is shown Figure 3 A schematic cross-sectional view of the layer structure of a long laminated substrate in a long sheet roll is shown. DETAILED DESCRIPTION

[0060] The following are detailed descriptions of the embodiments of the present disclosure. However, the present disclosure is not limited to the following embodiments. In the following embodiments, the constituent elements (including element steps, etc.) are not necessarily required unless otherwise specified. The numerical values ​​and their ranges are also not limiting to the present disclosure.

[0061] In addition, components having substantially the same function are denoted by the same reference numerals throughout the drawings, and duplicate descriptions may be omitted.

[0062] In the present disclosure, the term "process" includes a process that is independent of other processes, and also includes a process if the purpose of the process can be achieved without being clearly distinguished from other processes.

[0063] In the present disclosure, a numerical range represented by "to" includes the numerical values ​​described before and after "to" as a minimum value and a maximum value, respectively.

[0064] In the present disclosure, each component may include a plurality of corresponding substances. When a plurality of substances corresponding to each component are present in the composition, unless otherwise specified, the content rate or content of each component refers to the total content rate or total content of the plurality of substances present in the composition.

[0065] In the present disclosure, particles corresponding to each component may include multiple types. When multiple types of particles corresponding to each component are present in the composition, the particle size of each component is a value for a mixture of the multiple types of particles present in the composition unless otherwise specified.

[0066] In the present disclosure, the term “layer” or “film” includes not only the case where the layer or film is formed in the entire region when the region where the layer or film exists is observed, but also the case where the layer or film is formed in only a part of the region.

[0067] In the present disclosure, the term “stacked” refers to stacking layers, which may be two or more layers combined together, or two or more layers may be detachable.

[0068] When the embodiments are described with reference to the drawings in the present disclosure, the structure of the embodiments is not limited to the structure shown in the drawings. In addition, the dimensions of the components in each figure are schematic, and the relative relationship between the dimensions of the components is not limited thereto.

[0069] In the present disclosure, a "polymer" is a compound formed by polymerization of monomers. That is, a "polymer" has a plurality of units based on monomers.

[0070] In the present disclosure, a "unit" in a polymer refers to an atomic group based on a monomer formed by polymerization of the monomer. The unit may be a unit directly formed by a polymerization reaction, or a unit in which a part of the unit is converted into another structure by treating the polymer. Hereinafter, a unit based on monomer a is also referred to as a "monomer a unit".

[0071] In the present disclosure, the “weight average molecular weight” is determined by polystyrene conversion using gel permeation chromatography (GPC).

[0072] In the present disclosure, the “melting point” of a polymer refers to the temperature corresponding to the maximum value of the melting peak of the polymer measured by differential scanning calorimetry (DSC).

[0073] In the present disclosure, the “melt flow rate” of a polymer refers to the melt flow rate of a polymer specified in JIS K7210-1:2014 (ISO 1133-1:2011).

[0074] In the present disclosure, the “glass transition temperature (Tg)” of a polymer is a value measured by analyzing the polymer using a dynamic viscoelasticity measurement (DMA) method.

[0075] In the present disclosure, the "volume average particle size (D50)" of polymer particles is the volume-based cumulative 50% diameter of the particles determined by the laser diffraction / scattering method. That is, the particle size distribution is measured by the laser diffraction / scattering method, and a cumulative curve is obtained with the total volume of the particle group as 100%, and the particle size at the point where the cumulative volume reaches 50% on the cumulative curve.

[0076] The D50 of polymer particles is determined by dispersing the particles in water and analyzing them by a laser diffraction / scattering method using a laser diffraction / scattering particle size distribution analyzer (for example, LA-920 analyzer manufactured by Horiba, Ltd.).

[0077] In the present disclosure, the “average particle size” of the inorganic filler is the average value of the equivalent circle diameters of 100 particles randomly selected when the particles are observed using a scanning electron microscope (SEM).

[0078] In the present disclosure, the “specific surface area” is a value obtained by measuring and calculating particles using a gas adsorption (constant volume method) BET multipoint method, and is obtained using, for example, NOVA4200e (manufactured by Quantachrome Instruments).

[0079] In the present disclosure, "ten-point average roughness Rzjis" is a value specified in Appendix JA of JIS B 0601: 2013, and is measured in accordance with JIS B 0601: 2013. Specifically, it can be measured using, for example, a high-precision shape measurement system (e.g., "KS-1100" manufactured by KEYENCE Corporation, tip model "LT-9510VM") or the like.

[0080] In the present disclosure, the "viscosity" of a composition is determined by measuring the composition using a B-type viscometer at 25° C. and a rotation speed of 30 rpm. The measurement is repeated 3 times, and the average of the 3 measured values ​​is taken.

[0081] [Long-length laminated substrate and method for producing the same]

[0082] The long laminated substrate in one embodiment of the present disclosure has a substrate with a thickness of 12 to 50 μm and two polymer layers respectively arranged on both sides of the substrate, wherein the two polymer layers contain a tetrafluoroethylene polymer and each has a thickness of 12 to 40 μm, and the value of the root mean square slope Sdq measured on the surface opposite to the substrate according to ISO25178-2:2012 is less than 5 μm / mm. Hereinafter, the tetrafluoroethylene polymer is also referred to as "F polymer", the surface of the polymer layer on the opposite side to the substrate is also referred to as "exposed surface", and the value of the root mean square slope Sdq measured on the surface of the measurement object according to ISO25178-2:2012 is also referred to as "Sdq".

[0083] In this embodiment, "long strip" means that the length in the long side direction is more than 100 m. The length in the long side direction of the long strip laminated substrate is preferably more than 200 m. The length in the long side direction is preferably less than 1000 m.

[0084] The long-strip laminated substrate is stored as a roll-shaped substrate wound on a winding core, for example. Hereinafter, the roll-shaped substrate obtained by winding the long-strip laminated substrate on the winding core is also referred to as a "roll sheet". In addition, a laminated substrate obtained by unwinding a part of the long-strip laminated substrate from a roll sheet can be used, for example, to produce a metal-clad laminate. Specifically, for example, a metal foil is crimped onto the surface of the laminated substrate to obtain a metal-clad laminate.

[0085] As described above, the long laminated substrate obtained by respectively providing polymer layers containing F polymer on both sides of the substrate can be expected to have both the physical properties of F polymer and the physical properties of the substrate. For example, when a heat-resistant substrate containing a heat-resistant resin is used as the substrate, a long laminated substrate can be obtained that has both the physical properties such as heat resistance and dimensional stability and the electrical properties such as low dielectric constant and low dielectric loss tangent of the F polymer.

[0086] On the other hand, when the long laminated substrate is unwound after being wound on a winding core to form a roll sheet, the long laminated substrate may sometimes have undulations. Moreover, when a metal foil is crimped onto the surface of a laminated substrate obtained from the undulating long laminated substrate to produce a metal-clad laminate, the metal foil is easily peeled off due to the undulations of the long laminated substrate. In particular, when the total thickness of the two polymer layers is thicker than the thickness of the substrate, the peeling of the metal foil caused by the undulations of the long laminated substrate becomes particularly obvious.

[0087] In this regard, the Sdq of the exposed surfaces of the two polymer layers in this embodiment is less than 5 μm / mm. The above Sdq is a parameter calculated based on the root mean square of the slope of the surface of the measured object, which represents the average size of the local slope of the concave-convex shape. The larger the Sdq, the more drastic and steep the surface.

[0088] The present inventors have found that by setting Sdq rather than the unevenness height of the exposed surface within the above range, the peeling of the metal foil caused by the undulations of the long laminated substrate can be suppressed even if the thickness of the substrate is 12 to 50 μm and the thickness of each polymer layer is 12 to 40 μm.

[0089] Hereinafter, an example of the long-length laminated substrate will be described with reference to the drawings, but the long-length laminated substrate of the present disclosure is not limited thereto.

[0090] Figure 1 This is a schematic cross-sectional view showing the layer structure of a long laminated base material according to one embodiment.

[0091] Figure 1 The long laminated substrate 10 shown includes a substrate 12 and polymer layers 14 and 16 provided on both surfaces of the substrate 12. The exposed surfaces 14S and 16S of the polymer layer 14 and 16 have Sdq values ​​of 5 μm / mm or less.

[0092] Hereinafter, each layer constituting the long laminated substrate will be described. Note that reference numerals may be omitted.

[0093] The substrate may be a long film made of a resin, etc. The substrate may have a single-layer structure or a multi-layer structure.

[0094] The substrate is preferably a heat-resistant substrate, and more preferably a film containing a heat-resistant resin.

[0095] The substrate preferably comprises a heat-resistant resin. Examples of the heat-resistant resin include polyimide (aromatic polyimide, etc.), polyarylate, polysulfone, polyarylsulfone (polyethersulfone, etc.), aromatic polyamide, aromatic polyetheramide, polyphenylene sulfide, polyaryletherketone, polyamideimide, liquid crystal polyester, liquid crystal polyesteramide, polytetrafluoroethylene, etc.

[0096] The base material including the heat-resistant resin may further include a plasticizer, a resin other than the heat-resistant resin, a colorant, an inorganic filler, various additives, and the like.

[0097] As the inorganic filler, nitride fillers and inorganic oxide fillers are preferred, boron nitride fillers, beryllium oxide fillers (beryllium oxide fillers), silicate fillers (silicon dioxide fillers, wollastonite fillers, talc fillers) and metal oxide fillers (cerium oxide, aluminum oxide, magnesium oxide, zinc oxide, titanium oxide, etc.) are more preferred, and silica fillers are further preferred.

[0098] The additive may, for example, be an antistatic agent, a flame retardant, a heat stabilizer, an ultraviolet absorber, a lubricant, a mold release agent, a crystal nucleating agent or the like.

[0099] The total content of the heat-resistant resin in the substrate containing the heat-resistant resin is preferably 70% by mass or more, more preferably 80% by mass or more, and may be 100% by mass, based on the entire substrate.

[0100] From the viewpoint of heat resistance, the substrate preferably contains at least one selected from the group consisting of polyimide, liquid crystal polyester and polytetrafluoroethylene among the above-mentioned heat-resistant resins, and more preferably contains at least polyimide.

[0101] As the polyimide contained in the substrate including a polyimide, a polyimide obtained from a polyamic acid obtained by polymerizing an aromatic diamine component and a tetracarboxylic acid component may be mentioned.

[0102] Examples of the aromatic diamine component include p-phenylenediamine, 4,4'-diaminodiphenyl ether, 3,4'-diaminodiphenyl ether, 1,4-bis(4-aminophenoxy)benzene, 1,3-bis(4-aminophenoxy)benzene, 1,3-bis(3-aminophenoxy)benzene, 4,4'-bis(aminophenoxy)biphenyl, 4,4'-bis(3-aminophenoxy)biphenyl, and 2,2'-bis(4-aminophenoxyphenyl)propane. The aromatic diamine component may be used alone or in combination of two or more.

[0103] The tetracarboxylic acid component may, for example, be pyromellitic acid, 3,3',4,4'-biphenyltetracarboxylic acid, oxydiphthalic acid, 2,3',3,4'-biphenyltetracarboxylic acid, 3,3',4,4'-benzophenonetetracarboxylic acid, or dianhydrides thereof. The tetracarboxylic acid component may be used alone or in combination of two or more.

[0104] The glass transition temperature of the polyimide contained in the substrate including polyimide may be lower than 288° C., preferably lower than 275° C., and more preferably lower than 260° C. The glass transition temperature of the polyimide is preferably 200° C. or higher.

[0105] Specific examples of the substrate containing polyimide include "Kapton 50EN-S" (manufactured by DuPont Toray Co., Ltd.), "Kapton 100EN" (manufactured by DuPont Toray Co., Ltd.), "Kapton 100H" (manufactured by DuPont Toray Co., Ltd.), "Kapton 100KJ" (manufactured by DuPont Co., Ltd.), "Kapton 100JP" (manufactured by DuPont Co., Ltd.), and "Kapton 100LK" (manufactured by DuPont Toray Co., Ltd.).

[0106] The peeling of the metal foil due to the undulation becomes noticeable.

[0107] The tensile modulus of elasticity of the substrate at 320°C is preferably above 0.2GPa, more preferably above 0.3GPa. The above-mentioned tensile modulus of elasticity is preferably below 10GPa, more preferably below 5GPa. The tensile modulus of the substrate at 320°C is within the above-mentioned range, so deformation caused by heating and cooling is difficult to occur, and the operability is easy to be excellent. Specifically, if the above-mentioned tensile modulus of elasticity of the substrate is above the above-mentioned lower limit, the deformation of the polymer layer during heating and cooling during processing is easily alleviated by the elasticity of the substrate. In addition, if the tensile modulus of elasticity of the substrate is below the above-mentioned upper limit, the softness of the long strip laminated substrate tends to become high.

[0108] The thickness of the substrate is 12 to 50 μm, and preferably 20 to 44 μm from the viewpoint of dimensional stability of the laminated substrate.

[0109] From the viewpoint of dimensional stability of the laminated substrate, the length in the short-side direction of the substrate, that is, the width, is preferably 500 to 1250 mm.

[0110] The length of the substrate in the longitudinal direction is preferably 1000 to 100 μm.

[0111] The length of the substrate in the long-side direction is preferably 50 times or more, more preferably 100 times or more, greater than the width of the substrate. The length of the substrate in the long-side direction is preferably 1000 times or less, greater than the width of the substrate.

[0112] The polymer layer is a layer provided on both sides of the substrate, respectively.

[0113] The two polymer layers provided on both surfaces of the substrate are not particularly limited as long as both contain F polymer, each has a thickness of 12 μm to 40 μm, and the Sdq of the exposed surface is 5 μm / mm or less.

[0114] Both polymer layers are preferably arranged in direct contact with the substrate.

[0115] Each of the two polymer layers may contain only one type of polymer F, or may contain two or more types of polymer F. The compositions of the two polymer layers may be the same as or different from each other.

[0116] The F polymer is a polymer containing units based on tetrafluoroethylene (hereinafter also referred to as "TFE") (hereinafter also referred to as "TFE units"). The F polymer may further contain units based on other comonomers.

[0117] From the viewpoint of advantageously exhibiting the characteristics brought about by the TFE unit, the content of the TFE unit in the F polymer is preferably 50 mol% or more, more preferably 90 mol% or more relative to all the units in the F polymer. The above content may be below 99 mol% or below 98 mol%.

[0118] The F polymer may be heat-fusible or non-heat-fusible. When it is desired to exhibit particularly good properties such as thermal conductivity, adhesiveness, and processability, the F polymer is preferably heat-fusible.

[0119] A heat-fusible polymer is a polymer having a melt flow rate of 1 to 1000 g / 10 min under a load of 49 N. A non-heat-fusible polymer is a polymer having no melt flow rate of 1 to 1000 g / 10 min under a load of 49 N.

[0120] From the viewpoint of heat resistance of the polymer layer, the melting point of the heat-melting F polymer is preferably 200° C. or higher, more preferably 260° C. or higher. From the viewpoint of ease of processing, the melting point of the F polymer is preferably 325° C. or lower, more preferably 320° C. or lower.

[0121] The F polymer preferably has a melting point of 200 to 325°C, and more preferably has a melting point of 260 to 320°C.

[0122] From the viewpoint of heat resistance, the glass transition temperature of the F polymer is preferably 50° C. or higher, more preferably 75° C. or higher. From the viewpoint of processability, the glass transition temperature of the F polymer is preferably 150° C. or lower, more preferably 125° C. or lower.

[0123] From the viewpoint of advantageously expressing the properties attributed to fluorine atoms such as electrical properties and heat resistance, the fluorine content of the F polymer is preferably 70% by mass or more, more preferably 72 to 76% by mass.

[0124] The surface tension of the F polymer is preferably 16 to 26 mN / m. The surface tension of the F polymer can be measured by placing a drop of a wetting index reagent (manufactured by FUJIFILM Wako Pure Chemical Industries, Ltd.) on a flat plate made of the F polymer.

[0125] The F polymer is preferably polytetrafluoroethylene (PTFE), a polymer containing TFE units and units based on ethylene, a polymer containing TFE units and units based on propylene, a polymer containing TFE units and units based on perfluoro(alkyl vinyl ether) (PAVE) (PAVE units) (PFA), and a polymer containing TFE units and units based on hexafluoropropylene (FEP). From the viewpoint of thermal conductivity, adhesion, processability and other properties, PFA and FEP are more preferred, and PFA is further preferred. These polymers may further contain units based on other comonomers.

[0126] PAVE prefers CF2=CFOCF3, CF2=CFOCF2CF3 and CF2=CFOCF2CF2CF3 (with

[0127] PPVE is also referred to as "PPVE" below), with PPVE being more preferred.

[0128] From the viewpoint of adhesion to the substrate, the F polymer is preferably an F polymer having an oxygen-containing polar group, more preferably an F polymer having a hydroxyl group or a carbonyl group, and still more preferably an F polymer having a carbonyl group.

[0129] The hydroxyl group-containing group is preferably a group containing an alcoholic hydroxyl group, more preferably -CF2CH2OH and -C(CF3)2OH.

[0130] The carbonyl-containing group is a group containing a carbonyl group (>C(O)). The carbonyl-containing group is preferably a carboxyl group, an alkoxycarbonyl group, an amide group, an isocyanate group, a carbamate group (-OC(O)NH2), an anhydride residue (-C(O)OC(O)-), an imide residue (-C(O)NHC(O)-, etc.) and a carbonate group (-OC(O)O-), and an anhydride residue is more preferred.

[0131] The peeling of the metal foil due to the undulation becomes noticeable.

[0132] When the F polymer has an oxygen-containing polar group, the number of oxygen-containing polar groups in the F polymer is preferably 1×10 6 The number of main chain carbon atoms is 100 to 5000, more preferably 300 to 3000, and even more preferably 800 to 1500. In addition, the number of oxygen-containing polar groups in the F polymer can be quantified based on the composition of the polymer or the method described in International Publication No. 2020 / 145133.

[0133] The oxygen-containing polar group may be contained in the monomer-based unit in the F polymer or in the terminal group of the F polymer main chain, and the former form is preferred. As the latter form, there can be exemplified an F polymer having an oxygen-containing polar functional group as a terminal group derived from a polymerization initiator, a chain transfer agent, etc., and an F polymer obtained by subjecting the F polymer to plasma treatment or ionizing radiation treatment.

[0134] The monomer having a carbonyl group is preferably itaconic anhydride, citraconic anhydride, and 5-norbornene-2,3-dicarboxylic anhydride (hereinafter also referred to as "NAH"), and more preferably NAH.

[0135] The F polymer is preferably an F polymer having an oxygen-containing polar group containing a TFE unit and a PAVE unit, and more preferably an F polymer containing a TFE unit, a PAVE unit, and a unit based on a monomer having a carbonyl group (also referred to as F polymer (1)). Hereinafter, the unit based on a monomer having an oxygen-containing polar group is also referred to as an "oxygen-containing unit".

[0136] The F polymer (1) is more preferably a polymer (1) containing TFE units, PAVE units and oxygen-containing units in the order of 90 to 99 mol%, 0.5 to 9.97 mol%, and 0.01 to 3 mol% relative to all units. Specific examples of the F polymer (1) include polymers described in International Publication No. 2018 / 016644.

[0137] The F polymer may be an F polymer having no oxygen-containing unit (also referred to as F polymer (2)), or may be an F polymer having no oxygen-containing polar group.

[0138] The F polymer (2) is preferably a F polymer (2) having no oxygen-containing unit and containing 2.0 to 5.0 mol% of PAVE units based on all units.

[0139] The F polymer (2) is preferably composed of only TFE units and PAVE units and contains 95.0 to 98.0 mol % of TFE units and 2.0 to 5.0 mol % of PAVE units based on all units.

[0140] The content of the PAVE unit in the F polymer (2) is preferably 2.1 to 5.0 mol%, more preferably 2.2 to 5.0 mol%, based on all units.

[0141] The polymer (2) does not have an oxygen-containing polar group, which means that the number of carbon atoms constituting the polymer main chain is 1×10 6 The number of oxygen-containing polar groups in the polymer (2) is less than 500. The number of oxygen-containing polar groups is preferably 100 or less, more preferably less than 50. The lower limit of the number of oxygen-containing polar groups is usually 0.

[0142] The F polymer (2) can be produced using a polymerization initiator or chain transfer agent that does not generate an oxygen-containing polar group as an end group of the polymer chain, or by fluorinating an F polymer having an oxygen-containing polar group (an F polymer having an oxygen-containing polar group from a polymerization initiator at the end group of the polymer main chain). As a method for fluorination treatment, a method using fluorine gas can be cited (see Japanese Patent Laid-Open No. 2019-194314, etc.).

[0143] The content of the F polymer in the polymer layer is preferably 50% by mass or more, more preferably 60% by mass or more. The upper limit of the content of the F polymer is 100% by mass.

[0144] The polymer layer may further include other resins other than polymer F. The other resins may be thermosetting resins or thermoplastic resins.

[0145] From the viewpoint of UV absorbency of the polymer layer, the other resin is preferably an aromatic polymer.

[0146] As other resins, epoxy resin, maleimide resin, polyurethane resin, polyimide, polyamic acid, polyamide-imide, polyphenylene ether, polyphenylene ether, liquid crystal polyester, fluorine-containing polymers other than F polymer can be listed. From the viewpoint of the flexibility of the long laminated substrate, other resins are preferably maleimide resin, polyimide and polyamic acid. As other resins, more preferably all are aromatic maleimide resin, polyimide and polyamic acid. Polyimide is preferably thermoplastic.

[0147] The total content of maleimide, polyimide, and polyamic acid in the polymer layer is preferably 0.1 to 30% by mass, more preferably 1 to 10% by mass.

[0148] The ratio of the total content of maleimide, polyimide and polyamic acid to the content of the F polymer is preferably 1.0 or less, more preferably 0.01 to 0.5.

[0149] From the viewpoint of further improving the low linear expansion and electrical properties of the long laminated substrate, the polymer layer may further contain an inorganic filler.

[0150] As the inorganic filler, nitride fillers and inorganic oxide fillers are preferred, boron nitride fillers, beryllium oxide fillers (beryllium oxide fillers), silicate fillers (silicon dioxide fillers, wollastonite fillers, talc fillers) and metal oxide fillers (cerium oxide, aluminum oxide, magnesium oxide, zinc oxide, titanium oxide, etc.) are more preferred, and silica fillers are further preferred.

[0151] The content of silicon dioxide in the inorganic filler is preferably 50% by mass or more, more preferably 75% by mass or more. The upper limit of the content of silicon dioxide is 100% by mass.

[0152] It is preferred that at least a part of the surface of the inorganic filler be surface-treated with a silane coupling agent.

[0153] As the silane coupling agent, 3-aminopropyltriethoxysilane, vinyltrimethoxysilane, 3-mercaptopropyltrimethoxysilane, 3-glycidoxypropylmethyldiethoxysilane, 3-methacryloxypropyltriethoxysilane and 3-isocyanatepropyltriethoxysilane are preferred.

[0154] Specific examples of the inorganic filler include silica fillers (such as "admafin" series manufactured by Yaduma Tech Co., Ltd.), zinc oxide surface-treated with an ester such as propylene glycol dicaprate (such as "FINEX" series manufactured by Sakai Chemical Industry Co., Ltd.), spherical fused silica (such as "SFP" series manufactured by Denka Co., Ltd.), coated with a polyol and an inorganic substance (such as "TIPAQUE" series manufactured by Ishihara Sangyo Co., Ltd.), rutile titanium oxide surface-treated with an alkylsilane (such as "JMT" series manufactured by Teika Co., Ltd.), hollow silica fillers, and the like. Materials ("E-SPHERES" series manufactured by Pacific Cement Co., Ltd. (Pacific Cement Co., Ltd.), "SILINAX (シリナ) manufactured by Nippon Steel Mining Co., Ltd. "Eccospheres (Eccospheres)" series manufactured by Emerson Cuming Co., Ltd., etc.), talc filler ("SG" series manufactured by Nippon Talc Co., Ltd., etc.), block talc filler ("BST" series manufactured by Nippon Talc Co., Ltd., etc.), boron nitride filler ("UHP" series manufactured by Showa Denko K.K., "Denka Boron Nitride" series ("GP", "HGP" grade) manufactured by Denka Co., Ltd., etc.).

[0155] The content of the inorganic filler in the polymer layer is preferably 1% by mass or more, more preferably 3% by mass or more, and preferably 40% by mass or less, more preferably 30% by mass or less, and further preferably 20% by mass or less.

[0156] The ratio (mass ratio) of the content of the inorganic filler to the content of the F polymer in the polymer layer is preferably 0.01 or more, more preferably 0.1 or more. The above ratio is preferably 1 or less, more preferably 0.8 or less.

[0157] In addition to the above components, the polymer layer may also contain additives such as silane coupling agent, dehydrating agent, plasticizer, weathering agent, antioxidant, heat stabilizer, lubricant, antistatic agent, brightener, colorant, conductive agent, release agent, surface treatment agent, flame retardant, etc.

[0158] The polymer layer is preferably a layer of a sintered body containing particles of tetrafluoroethylene polymer, i.e., particles of F polymer. Hereinafter, particles of tetrafluoroethylene polymer are also referred to as "F particles". In addition, whether the polymer layer contains a sintered body of F particles can be confirmed by observing the cross section of the polymer layer using a microscope or the like.

[0159] When the polymer layer is a layer containing F particles, the polymer layer may contain components other than F particles. Components other than F particles include components other than the above-mentioned F polymers, specifically, resins other than F polymers, inorganic fillers, additives, etc.

[0160] From the viewpoint of dispersion stability in a liquid dispersion medium and ease of control of Sdq, the D50 of the F particles is preferably 0.1 μm or more, more preferably greater than 0.3 μm, and further preferably 1 μm or more. From the viewpoint of dispersion stability in a liquid dispersion medium and ease of control of Sdq, the D50 of the F particles is preferably 25 μm or less, more preferably 10 μm or less, further preferably 8 μm or less, and particularly preferably 6 μm or less.

[0161] The specific surface area of ​​the F particles is preferably 1 to 25 m 2 / g.

[0162] The F particles may be used alone or in combination of two or more.

[0163] The content of the F polymer in the F particles is preferably 80% by mass or more, more preferably 100% by mass. That is, the F particles are preferably particles composed of the F polymer.

[0164] As a component other than the F polymer which may be contained in the F particles, a resin other than the F polymer, an inorganic filler, etc. may be mentioned.

[0165] The thickness of each of the two polymer layers is 12 to 40 μm, preferably 16 to 36 μm, and more preferably 20 to 33 μm from the viewpoint of dimensional stability of the laminated substrate.

[0166] From the viewpoint of suppressing the occurrence of undulations in the long laminated substrate, the thickness of one of the two polymer layers is preferably 0.9 to 1.1 times the thickness of the other polymer layer.

[0167] From the viewpoint of the electrical properties of the laminated substrate, the total thickness of the two polymer layers is preferably 1.8 to 3.0 times the thickness of the substrate, more preferably 1.8 to 2.4 times. It is particularly preferred that the thickness of one of the two polymer layers is 0.9 to 1.1 times the thickness of the other polymer layer, and the total thickness of the two polymer layers is 1.8 to 3.0 times the thickness of the substrate.

[0168] In this embodiment, since the Sdq of the exposed surface of the polymer layer is 5 μm / mm or less, even if the total thickness of the two polymer layers is 1.8 times or more the thickness of the substrate, the long laminated substrate can be prevented from undulating.

[0169] The Sdq of the exposed surfaces of the two polymer layers is 5 μm / mm or less, preferably 4 μm / mm or less, and more preferably 3 μm / mm or less. The Sdq is preferably 0 μm / mm or more.

[0170] Sdq is obtained by measuring the exposed surface in accordance with ISO 25178-2: 2012. Examples of the measuring method include a contact method, a white light interferometer method, and a point autofocus method.

[0171] The measurement using white light interferometry and the calculation of Sdq were performed under the following conditions: using a surface property measuring instrument (manufactured by Zygo Corporation, product name: Newview 7300), magnification: 1.4×0.5 times, scanning pitch: 100 μm, analysis size: 12.621 mm 2 , Filter type: Spline, Filter: Low Pass high frequency 1μm, Type: Gussian Spline Fixed.

[0172] The Sdq of the exposed surface of the polymer layer can be controlled by the method and formation conditions for forming the polymer layer, for example, when the polymer layer is a layer of a sintered body containing F particles. Specifically, for example, a composition containing F particles and a liquid dispersion medium is applied to the surface of a substrate and heat-treated to form a polymer layer, and when applying the composition, the ten-point average roughness Rzjis of the outer peripheral surface of the backing roller used and the contact surface pressure of the substrate to the backing roller are adjusted to the following ranges.

[0173] Hereinafter, an example of a method for producing a long laminated substrate according to the present embodiment in which the Sdq of the exposed surface of the polymer layer is 5 μm / mm or less will be described.

[0174] <Method for producing long laminated substrate>

[0175] A method for manufacturing a long laminated substrate in one embodiment includes: conveying the substrate while bringing the second surface of a long substrate with a thickness of 12 to 50 μm into contact with the outer peripheral surface of a back roller having a ten-point average roughness Rzjis of 0.5 to 10 μm at a contact surface pressure of 100 to 3000 kPa, coating a composition containing particles of a tetrafluoroethylene polymer (i.e., F particles) and a liquid dispersion medium on the first surface of the substrate and heat treating the composition, thereby forming a first layer on the first surface; and conveying the substrate while bringing the first layer into contact with the outer peripheral surface of the back roller at a contact surface pressure of 100 to 3000 kPa, coating the composition on the second surface and heat treating the composition, thereby forming a second layer on the second surface.

[0176] According to the method for producing a long laminate substrate of this embodiment, through the above steps, a long laminate substrate including the above substrate, a first polymer layer including F polymer and having a thickness of 12 to 40 μm, and a second polymer layer including F polymer and having a thickness of 12 to 40 μm is obtained.

[0177] Hereinafter, the ten-point average roughness Rzjis of the outer peripheral surface of the backing roller is also simply referred to as “Rzjis”, and the contact surface pressure of the substrate to the outer peripheral surface of the backing roller is also simply referred to as “contact surface pressure”.

[0178] In addition, the first polymer layer is also referred to as a "P-A1 layer", and the second polymer layer is also referred to as a "P-A2 layer."

[0179] By using the above manufacturing method to manufacture a long laminated substrate, a long laminated substrate having an Sdq of 5 μm / mm or less on the exposed surface of the two polymer layers can be obtained. The reason is not clear, but it is speculated that the reason is that by making Rzjis and the contact surface pressure within the above range, it is possible to simultaneously suppress the stick-slip phenomenon caused by the substrate adhering to the backing roller and suppress the concavo-convex shape of the outer peripheral surface of the backing roller from being transferred to the exposed surface of the polymer layer.

[0180] Specifically, by making Rzjis within the above range, the substrate is less likely to adhere to the backing roll than when Rzjis is less than the above range, and the phenomenon of repeated adhesion and slippage of the substrate on the outer peripheral surface of the backing roll, i.e., the stick-slip phenomenon, can be suppressed. Therefore, the periodic fluctuation of the thickness of the formed polymer layer due to the stick-slip phenomenon is suppressed, and it is estimated that the Sdq of the exposed surface of the obtained polymer layer is reduced.

[0181] In addition, by making Rzjis within the above range, compared with the case where it is greater than the above range, the temporary transfer of the concavo-convex shape of the outer peripheral surface of the backing roller to the exposed surface of the polymer layer when the substrate contacts the backing roller can be suppressed. Therefore, the unevenness caused by the flow of the applied composition due to the temporary transfer of the concavo-convex shape is suppressed, and it is estimated that the Sdq of the exposed surface of the polymer layer is reduced.

[0182] In addition, by making the contact surface pressure within the above range, it is possible to suppress air from being drawn in between the substrate and the outer peripheral surface of the backing roller, compared with the case where the contact surface pressure is less than the above range. Here, if air is drawn in between the substrate and the outer peripheral surface of the backing roller, uneven coating of the composition may occur between the portion where the air is drawn in and the portion where the air is not drawn in. However, by making the contact surface pressure within the above range, the above uneven coating can be suppressed, and as a result, it is estimated that the Sdq of the exposed surface of the obtained polymer layer is reduced.

[0183] Furthermore, by setting the contact surface pressure within the above range, the substrate is less likely to adhere to the backing roll, and the stick-slip phenomenon is suppressed, compared with the case where the contact surface pressure exceeds the above range, and it is estimated that the Sdq of the exposed surface of the obtained polymer layer is reduced.

[0184] The manufacturing method of the long laminated substrate of this embodiment may also include winding the obtained long laminated substrate on a winding core to form a rolled substrate (i.e., a rolled sheet). After the step of winding the obtained long laminated substrate on the core material, a rolled sheet formed by winding the long laminated substrate on the winding core is obtained.

[0185] Hereinafter, an example of a method for producing the long laminated base material according to the present embodiment will be described.

[0186] In addition, the long substrate and the P-A1 layer and the P-A2 layer in the obtained long laminated substrate are the same as the above-mentioned substrate and polymer layer, and therefore their description is omitted.

[0187] Figure 2 This is a schematic diagram schematically showing a coating section of an apparatus used in the method for producing a long laminated substrate according to the present embodiment.

[0188] like Figure 2 As shown, the coating section of the apparatus used in the method for producing the long laminated substrate of the present embodiment includes a backing roll 20 for conveying the substrate 12 to be coated and a coating member 22 for coating the coating composition on the coating surface of the substrate 12 .

[0189] exist Figure 2 In the coating section shown, the backing roller 20 rotates and conveys the substrate 12 in a state where the surface of the substrate 12 opposite to the coating surface is pressed against the outer peripheral surface of the backing roller 20. On the other hand, the polymer layer forming composition is coated on the coating surface side of the substrate 12 by the coating member 22 to form a composition layer 26.

[0190] The material of the backing roller 20 may be any one of metal, rubber and resin. As the backing roller 20, a roller having an elastic layer including at least one selected from rubber and resin provided on the outer peripheral surface of a cylindrical metal substrate may be exemplified. In addition, as the material of the metal substrate, for example, iron, stainless steel, titanium, aluminum and the like may be exemplified.

[0191] The outer diameter of the backing roll 20 is not particularly limited, and may be, for example, 100 to 500 mm, or 150 to 350 mm.

[0192] The Rzjis of the outer peripheral surface of the backing roll 20 is 0.5 to 10 μm, preferably 0.5 to 8 μm, and more preferably 1 to 6 μm from the viewpoint of forming a polymer layer with a small Sdq of the exposed surface.

[0193] The measurement and calculation of Rzjis can be performed in accordance with JIS B 0601:2013, for example, using a high-precision shape measuring system (for example, "KS-1100" manufactured by KEYENCE Corporation, tip model "LT-9510VM").

[0194] Rzjis can be adjusted by polishing the outer peripheral surface of the backing roll 20 , or by the type and amount of components (such as inorganic fillers) added when forming the outermost layer of the backing roll 20 .

[0195] The contact surface pressure of the substrate 12 to the outer peripheral surface of the backing roll 20 is 100 to 3000 kPa, preferably 200 to 2000 kPa, more preferably 250 to 2000 kPa, and further preferably 250 to 1000 kPa from the viewpoint of forming a polymer layer with a small Sdq of the exposed surface.

[0196] The contact surface pressure when forming the first layer and the contact surface pressure when forming the second layer may be the same or different. The contact surface pressure when forming the second layer is preferably 0.8 to 1.2 times, more preferably 0.9 to 1.1 times, and even more preferably substantially the same as the contact surface pressure when forming the first layer.

[0197] The contact surface pressure can be measured by, for example, a surface pressure distribution system manufactured by NITTA CORPORATION.

[0198] Specifically, for example, a sensor sheet of a surface pressure distribution system (manufactured by Neptuno Co., Ltd.) is sandwiched between the backing roll 20 and the substrate 12, and the value obtained by measurement is the above-mentioned contact surface pressure.

[0199] The above-mentioned contact surface pressure can be adjusted by the unwinding tension of the substrate 12, and can also be adjusted by the winding tension of the substrate 12.

[0200] The composition applied to the coating surface of the substrate 12 contains F particles and a liquid dispersion medium.

[0201] The content of the F particles in the composition is preferably 5 to 60% by mass, more preferably 25 to 50% by mass.

[0202] The details of the F particles are as described above, and thus the description thereof will be omitted.

[0203] When forming a polymer layer containing components other than F particles (resins other than F polymers, inorganic fillers, additives, etc.), the composition may contain components other than the above-mentioned F particles.

[0204] The details of the resins other than the F polymer and the inorganic filler are already described above, and therefore their description is omitted.

[0205] The liquid dispersion medium is a compound that is liquid at 25° C. under atmospheric pressure, preferably a compound with a boiling point of 50 to 240° C. One liquid dispersion medium may be used, or two or more liquid dispersion media may be used. When two liquid dispersion media are used, the two liquid dispersion media are preferably miscible with each other.

[0206] The liquid dispersion medium is preferably a compound selected from water, amides, ketones and esters.

[0207] Examples of the amide include N-methyl-2-pyrrolidone, N,N-dimethylformamide, N,N-dimethylacetamide, N,N-dimethylpropionamide, 3-methoxy-N,N-dimethylpropionamide, 3-butoxy-N,N-dimethylpropionamide, N,N-diethylformamide, hexamethylphosphoric triamide, and 1,3-dimethyl-2-imidazolidinone.

[0208] As the ketone, acetone, methyl ethyl ketone, methyl isopropyl ketone, methyl isobutyl ketone, methyl n-amyl ketone, methyl isoamyl ketone, 2-heptanone, cyclopentanone, cyclohexanone and cycloheptanone can be mentioned.

[0209] Examples of the ester include methyl acetate, ethyl acetate, butyl acetate, methyl lactate, ethyl lactate, methyl pyruvate, ethyl pyruvate, methyl methoxypropionate, ethyl ethoxypropionate, ethyl 3-ethoxypropionate, γ-butyrolactone, and γ-valerolactone.

[0210] Among them, from the viewpoint of versatility of an apparatus that can be used for production, the liquid dispersion medium is preferably a dispersion medium containing water.

[0211] From the viewpoint of improving the dispersion stability of the F particles, the liquid dispersion medium preferably further contains a nonionic surfactant.

[0212] Examples of the nonionic surfactant include acetylene-based surfactants, silicone-based surfactants and fluorine-based surfactants.

[0213] Specific examples of the nonionic surfactant include the "FTERGENT" series (manufactured by NEOUS Co., Ltd.), the "SURFLON (registered trademark)" series (manufactured by AGC Seimi Chemical Co., Ltd.), the "MEGAFACE (registered trademark)" series (manufactured by DIC Corporation), the "UNIDYNE" series (manufactured by Daikin Industries, Ltd.), "BYK-347", "BYK-349", "BYK-378", "BYK-3450", "BYK-3451", "BYK-3455", "BYK-3456" (manufactured by BYK Chemical Japan Co., Ltd.), "KF-6011", "KF-6043" (manufactured by Shin-Etsu Chemical Co., Ltd.), and "Tergitol" series ("Tergitol TMN-100X" manufactured by The Dow Chemical Company, etc.).

[0214] When the liquid dispersion medium contains a nonionic surfactant, the content of the nonionic surfactant in the liquid dispersion medium is preferably 1 to 10% by mass, more preferably 2.5 to 8% by mass, and further preferably 4 to 6% by mass, from the viewpoint of reducing the surface tension of the liquid dispersion medium.

[0215] The surface tension of the liquid dispersion medium is, for example, in the range of 20 to 35 mN / m, preferably 20 to 30 mN / m. When the surface tension of the liquid dispersion medium is within the above range, the composition can easily adapt to the surface of the substrate, and a polymer layer with a small Sdq on the exposed surface can be easily obtained.

[0216] The surface tension of the liquid dispersion medium is a value measured at 25° C. using a duNouy surface tension meter in accordance with JIS K 2241: 2007. When measuring the surface tension of the liquid dispersion medium contained in the composition, the surface tension is measured after removing solid components such as F particles from the composition by filtration or the like.

[0217] The content of the liquid dispersion medium is preferably 30% by mass or more, more preferably 40% by mass or more, relative to the total mass of the composition. The content of the liquid dispersion medium is preferably 80% by mass or less, more preferably 60% by mass or less, relative to the total mass of the composition. The content of the liquid dispersion medium refers to the total amount of the substance after removing the solid component from the composition.

[0218] The solid content concentration in the composition is preferably 20% by mass or more relative to the total mass of the composition, more preferably 40% by mass or more. The solid content concentration is preferably 70% by mass or less, more preferably 60% by mass or less. In addition, the solid content refers to the total amount of substances forming the solid content in the molded product formed by the composition. Specifically, the F particles are included in the solid content, and when the composition includes other resins, the other resins are also included in the solid content, and when the composition includes inorganic fillers, the inorganic fillers are also included in the solid content.

[0219] The composition may further contain additives such as thixotropy imparting agents, viscosity modifiers, defoaming agents, dehydrating agents, plasticizers, weathering agents, antioxidants, heat stabilizers, lubricants, antistatic agents, whitening agents, colorants, conductive agents, release agents, surface treatment agents, flame retardants, and various fillers represented by conductive fillers.

[0220] The viscosity of the composition is preferably 10 mPa·s or more, more preferably 100 mPa·s or more, and the viscosity of the composition is preferably 10000 mPa·s or less, more preferably 3000 mPa·s or less.

[0221] By making the viscosity of the composition within the above range, the composition layer is more easily retained on the surface of the substrate, and the uneven thickness of the composition layer due to liquid dripping, etc. is suppressed, and it is easier to obtain a polymer layer with a small Sdq on the exposed surface. In addition, by making the viscosity of the composition within the above range, the thickness of the composition layer is more easily uniform, and it is easier to obtain a polymer layer with a small Sdq on the exposed surface, compared with the case where the viscosity of the composition is higher than the above range.

[0222] In order to adjust the viscosity of the composition to the above range, the liquid dispersion medium of the composition may contain a thickener.

[0223] The thickener may, for example, be a polyurethane thickener, a polyacrylic acid thickener, a polyamide thickener, a cellulose thickener, or a thickener made of clay minerals such as bentonite.

[0224] When the liquid dispersion medium contains a thickener, the content of the thickener in the liquid dispersion medium may be in the range of 0.1 to 5 mass %.

[0225] The composition is obtained by mixing the F particles with other resins, inorganic fillers, liquid dispersion media, additives, etc. as required. The order of mixing is not particularly limited, and the mixing method may be a single mixing or a multiple mixing.

[0226] Examples of the mixing device for obtaining the composition include stirring devices with blades such as Henschel mixers, pressure kneaders, Banbury mixers and planetary mixers; pulverizing devices with media such as ball mills, crushers, basket mills, sand mills, sand mills, DYNO mills, DISPERMAT dispersers, SC mills, Spike mills and stirred mills; and dispersing devices with other mechanisms such as microfluidizers, nanometers, Ultimaizer dispersers, ultrasonic homogenizers, dissolvers, dispersers, high-speed impellers, thin film rotary high-speed mixers, rotational revolution mixers and V-type mixers.

[0227] Examples of methods for applying the composition onto the coating surface of the substrate 12 include spraying, roller coating, spin coating, gravure coating, micro gravure coating, gravure offset coating, knife coating, touch roller coating, rod coating, die coating, injection Meyer wire rod coating, slit die coating, and small diameter gravure reverse coating.

[0228] The conveying speed of the substrate 12 when applying the composition to the coating surface of the substrate 12 is not particularly limited, and may be, for example, 2 to 50 m / min.

[0229] Examples of a method for heat-treating the composition layer 26 formed by applying the composition on the coating surface of the substrate 12 include a method using an oven, a method using a ventilated drying furnace, and a method of irradiating with heat rays such as infrared rays.

[0230] The atmosphere during the heat treatment may be any state under normal pressure or reduced pressure. In addition, the above-mentioned atmosphere may be any one of an oxidizing gas (oxygen, etc.) atmosphere, a reducing gas (hydrogen, etc.) atmosphere, and an inert gas (rare gas, nitrogen) atmosphere.

[0231] Examples of heat treatment include heat treatment for the purpose of removing at least a portion of the liquid dispersion medium contained in the composition layer 26 (hereinafter also referred to as "drying treatment"), heat treatment for the purpose of calcining the F particles contained in the composition layer 26 (hereinafter also referred to as "calcining treatment"), and the like.

[0232] The heating temperature in the drying treatment is preferably 120 to 200° C. The holding time of the heating temperature in the drying treatment is preferably 0.1 to 10 minutes. Drying may be performed in a single step or in two or more steps at different temperatures.

[0233] The heating temperature in the calcination treatment is preferably a temperature above the melting point of the F polymer, specifically preferably 280 to 400° C., more preferably 300 to 380° C. The holding time of the heating temperature in the calcination treatment is preferably 0.5 to 30 minutes. The calcination treatment may be performed in a single stage or in two or more stages at different temperatures.

[0234] The heat treatment in the step of heat-treating the composition layer 26 formed on the first surface of the substrate 12 to form the first layer may be only a drying treatment, or only a sintering treatment, or a heat treatment including both a drying treatment and a sintering treatment performed after the drying treatment. That is, the first layer may be a layer in which the composition layer 26 has been dried and the F particles are in an unsintered state, or may be a P-Al layer including a sintered body formed by sintering the F particles.

[0235] After forming the first layer on the first surface of the substrate 12, the heat treatment in the step of forming the second layer by heat-treating the composition layer 26 formed on the second surface of the substrate 12 may be only a calcination treatment, or a heat treatment including both a drying treatment and a calcination treatment performed after the drying treatment. By subjecting the composition layer 26 formed on the second surface of the substrate 12 to at least the heat treatment, a second polymer layer as the second layer can be formed on the second surface of the substrate 12.

[0236] When no firing treatment is performed in the process of forming the first layer, that is, when the F particles of the first layer are not fired, the first layer will also be fired in the firing treatment in the process of forming the second layer, and a P-A1 layer including a sintered body formed by firing the F particles will be obtained.

[0237] The core used in the step of winding the obtained long laminated substrate on the core to form a rolled sheet is not particularly limited, and may be a cylindrical member having an axial length equal to or greater than the width of the substrate 12. Here, the cylindrical core may be a cylindrical core having a cavity or a cylindrical core without a cavity.

[0238] The material of the core is not particularly limited, and examples thereof include resin, rubber, metal, and combinations thereof.

[0239] When the winding core is cylindrical, the outer diameter of the winding core may be 50 to 240 mm, and the curvature of the outer peripheral surface of the winding core may be 0.009 to 0.049 mm. -1 .

[0240] When the core is a cylindrical core having a cavity, the thickness of the core is not particularly limited, but is preferably 5 mm or more from the viewpoint of maintaining the strength of the core.

[0241] The winding stress applied to the long laminated substrate when the obtained long laminated substrate is wound on the outer peripheral surface of the winding core is preferably 1 to 3 MPa. By making the winding stress within the above range, the winding deviation of the long laminated substrate while being offset in the axial direction of the winding core is suppressed compared to the case where the winding stress is less than the above range. In addition, by making the winding stress within the above range, the curling of the long laminated substrate unwound after being made into a roll sheet is suppressed compared to the case where the winding stress is greater than the above range.

[0242] The total thickness of the long laminated substrate is 36 μm or more, preferably 50 μm or more, and more preferably 75 μm or more from the perspective of dimensional stability of the laminated substrate. The total thickness of the long laminated substrate is 130 μm or less, preferably 120 μm or less, and more preferably 100 μm or less from the same perspective.

[0243] From the viewpoint of dimensional stability of the laminated base material, the length in the short-side direction of the long laminated base material, that is, the width, is preferably 500 to 1250 mm.

[0244] The length of the long laminated substrate in the longitudinal direction is preferably 100 to 1000 m.

[0245] The length of the long laminated substrate in the longitudinal direction is preferably 50 times or more, more preferably 100 times or more, and preferably 1000 times or less, of the width of the long laminated substrate.

[0246] The long laminated base material of the present embodiment can be used, for example, for the production of a metal-clad laminate for producing a printed wiring board.

[0247] The metal-clad laminate includes, for example, a laminate base obtained by cutting a portion of the long laminate base of this embodiment, and a metal foil layer provided on one surface of the laminate base.

[0248] Examples of the metal constituting the metal foil layer include copper, copper alloys, stainless steel, nickel, nickel alloys (including 42 alloy), aluminum, aluminum alloys, titanium, and titanium alloys.

[0249] As the metal foil for forming the metal foil layer, copper foil is preferred. As the copper foil, rolled copper foil, electrolytic copper foil, sputtered copper foil, electroless copper foil, etc. can be cited. Among them, the copper foil is more preferably a rolled copper foil that does not distinguish between the front and back sides, and an electrolytic copper foil that distinguishes between the front and back sides, and is further preferably a rolled copper foil. Since the rolled copper foil has a small surface roughness, it can also reduce the transmission loss when the metal-clad laminate is processed into a printed wiring substrate. The rolled copper foil is preferably immersed in a hydrocarbon organic solvent to remove the rolling oil before use.

[0250] The thickness of the metal foil layer is preferably less than 20 μm, more preferably 2 to 15 μm.

[0251] As a method for manufacturing a metal-clad laminate, for example, a method of cutting a portion of the long laminate substrate of the present embodiment to obtain a laminate substrate, and then providing a metal foil layer on the exposed surface of the polymer layer of the laminate substrate can be cited. As a method of providing a metal foil layer on a laminate substrate, a method of stacking a laminate substrate and a metal foil in such a manner that the metal foil is in contact with the exposed surface of the polymer layer of the laminate substrate, hot pressing and bonding them can be cited; a method of forming a metal foil layer by directly plating on the exposed surface of the polymer layer of the laminate substrate, etc. The method for manufacturing a metal-clad laminate can also be a method of unwinding the long laminate substrate of the present embodiment and a long metal foil together, and providing a metal foil layer on the exposed surface of the polymer layer of the long laminate substrate to obtain a long metal-clad laminate.

[0252] The metal-clad laminate has excellent electrical properties, heat resistance such as reflow soldering resistance, hole processing, chemical resistance, surface smoothness, etc. Therefore, the metal-clad laminate is suitable as a printed wiring board material and can be easily and efficiently processed into a flexible printed wiring board, a rigid printed wiring board, etc.

[0253] The transmission circuit is formed by etching the metal foil layer of the metal-clad laminate, thereby obtaining a printed wiring board. That is, the method for manufacturing a printed wiring board is a method for obtaining a printed wiring board by etching the metal foil of the metal-clad laminate to form a transmission circuit. In addition, etching can be performed by either a wet etching method or a dry etching method.

[0254] In the manufacture of the printed wiring board, after forming the transmission circuit, an interlayer insulating film may be formed on the transmission circuit, and then a conductor circuit may be formed on the interlayer insulating film.

[0255] [Long sheet roll and method for producing the same]

[0256] A long sheet roll according to one embodiment of the present disclosure comprises a cylindrical winding core and a long laminated substrate wound on the outer peripheral surface of the winding core, wherein the long laminated substrate comprises a substrate with a thickness of 12 to 50 μm and two polymer layers respectively arranged on both sides of the substrate, wherein the two polymer layers comprise a tetrafluoroethylene polymer and each has a thickness of 12 to 40 μm, wherein the total thickness of the two polymer layers is 1.8 to 3.0 times the thickness of the substrate, wherein the thickness of one of the two polymer layers is 0.9 to 1.1 times the thickness of the other polymer layer, and the curvature Cmm of the outer diameter of the winding core -1 The value of the product C×T of the total thickness Tmm of the long laminated base material is less than 0.0015.

[0257] Hereinafter, the tetrafluoroethylene polymer is also referred to as "F polymer", the curvature of the outer diameter of the winding core is also referred to as "curvature", the total thickness of the long laminated substrate is also referred to as "laminated thickness", and the curvature Cmm is also referred to as -1 The product of the stacking thickness Tmm is also referred to as "product C×T".

[0258] In this embodiment, "long strip" means that the length in the long side direction is more than 100 m. The length in the long side direction of the long strip laminated substrate is preferably more than 200 m. The length in the long side direction is preferably less than 1000 m.

[0259] The long sheet roll formed by winding the long laminated substrate on the outer peripheral surface of the winding core can be used, for example, to produce a metal-clad laminate. Specifically, for example, a metal foil is pressed onto the surface of a laminated substrate obtained by unwinding a portion of the long laminated substrate from the long sheet roll, thereby obtaining a metal-clad laminate.

[0260] For a long laminated substrate having polymer layers containing F polymers disposed on both sides of a substrate, it is expected that the physical properties of the F polymer and the physical properties of the substrate are simultaneously possessed. For example, when a heat-resistant substrate containing a heat-resistant resin is used as the substrate, a long laminated substrate having physical properties such as heat resistance and dimensional stability and electrical properties such as low dielectric constant and low dielectric loss tangent, which are the physical properties of the F polymer, can be obtained.

[0261] On the other hand, in the long sheet roll obtained by winding the above-mentioned long laminated substrate on the winding core, when the long laminated substrate is unwound to form a metal-clad laminate, the metal foil sometimes wrinkles. Moreover, when the metal foil wrinkles, it is easy to induce obstacles (deterioration of yield, reduction of product quality, etc.) when manufacturing printed wiring substrates, etc. The reason for the wrinkles in the above-mentioned metal foil is speculated to be caused by the curling of the long laminated substrate after unwinding. In particular, it is believed that by increasing the total thickness of the polymer layer containing the F polymer relative to the thickness of the substrate, the long laminated substrate is more likely to curl.

[0262] In contrast, in the present embodiment, the following structure is adopted: the total thickness of the two polymer layers is 1.8 to 3.0 times the thickness of the substrate, the thickness of one of the two polymer layers is 0.9 to 1.1 times the thickness of the other polymer layer, and the product C×T is less than 0.0015. The present inventors have found that by adopting the above structure, the curling of the long laminated substrate can be suppressed, and the wrinkling of the metal foil caused by the curling can be suppressed. The reason is not clear, but it is speculated as follows.

[0263] The above curvature is a value indicating the degree of curvature of the outer circumference of the core. The deeper the curvature, the greater the curvature value. For example, the curvature of a circle with a radius of r is 1 / r. When a long laminated substrate is wound on a cylindrical core, different stresses will be generated between the outer polymer layer and the inner polymer of the long laminated substrate. Moreover, the greater the curvature of the core, the greater the difference between the stress generated in the outer polymer layer and the stress generated in the inner polymer layer, and curling is likely to occur due to the strain caused by the above stress difference.

[0264] On the other hand, rather than simply reducing the curvature, the product C×T is made less than 0.0015, and the ratio of the total thickness of the two polymer layers to the thickness of the substrate is made 1.8 times or more, so that the stress difference during winding is easily absorbed by the long laminated substrate. In addition, it is presumed that the strain of the polymer layer that causes curling during unwinding is buffered, thereby suppressing the occurrence of curling.

[0265] Hereinafter, an example of the long sheet roll according to the present embodiment will be described with reference to the drawings, but the long sheet roll of the present disclosure is not limited thereto.

[0266] Figure 3 It is a perspective view schematically showing the long sheet roll according to the present embodiment. Figure 4 It is shown Figure 3 A schematic cross-sectional view of the layer structure of a long laminated substrate in a long sheet roll is shown.

[0267] Figure 3 The long sheet roll 100 shown in the figure has a cylindrical winding core 120 and a long laminated substrate 10 wound around the outer peripheral surface of the winding core 120. The long laminated substrate 10 is as shown in FIG. Figure 4 As shown, there is a substrate 12 and polymer layers 14 and 16 respectively disposed on both sides of the substrate 12 .

[0268] The core is not particularly limited as long as it is a cylindrical core, and may be a cylindrical member having an axial length equal to or greater than the short side length (hereinafter also referred to as "width") of the long laminated substrate described later. Here, the cylindrical core may be a cylindrical core having a cavity or a cylindrical core without a cavity.

[0269] The material of the winding core is not particularly limited, and examples thereof include resin, rubber, metal, and combinations thereof, etc. From the viewpoint of handleability and dimensional stability, the material of the winding core is preferably resin or rubber.

[0270] The outer diameter of the winding core may be 50 to 240 mm, and is preferably 80 to 200 mm, more preferably 90 to 185 mm, from the viewpoint of suppressing curling of the long laminated substrate.

[0271] The curvature may be 0.009 to 0.037 mm. -1 , from the viewpoint of suppressing the curling of the long laminated substrate, preferably 0.010 to 0.025 mm -1 , more preferably 0.011 to 0.022 mm -1 .

[0272] The axial length of the winding core may be equal to or longer than the length of the short side of the long laminated substrate, and may be, for example, in the range of 500 to 1250 mm.

[0273] When the core is a cylindrical core having a cavity, the thickness of the core is not particularly limited, but is preferably 5 mm or more from the viewpoint of maintaining the strength of the core.

[0274] The product C×T is less than 0.0015, and is preferably 0.0012 or less, and more preferably 0.00120 or less, from the viewpoint of suppressing curling of the long laminated substrate. The lower limit of the product C×T is preferably 0.0010 or more.

[0275] The substrate may be the same substrate as in the above-mentioned long laminated substrate and the method for producing the same, and preferred embodiments of the substrate are also the same as in the above-mentioned long laminated substrate and the method for producing the same.

[0276] In addition, the thickness of the substrate, the length in the short side direction of the substrate, i.e. the width, and the length in the long side direction of the substrate are also the same as those of the substrate in the above-mentioned long strip stacked substrate and its manufacturing method, and the preferred method is also the same as the above-mentioned long strip stacked substrate and its manufacturing method.

[0277] The polymer layer is a layer provided on both sides of the substrate, respectively.

[0278] The two polymer layers provided on both surfaces of the substrate are not particularly limited as long as both are layers containing the F polymer and each has a thickness of 12 to 40 μm.

[0279] Both polymer layers are preferably arranged in direct contact with the substrate.

[0280] Each of the two polymer layers may contain only one type of polymer F, or may contain two or more types of polymer F. The compositions of the two polymer layers may be the same as or different from each other.

[0281] Examples of the F polymer, including preferred embodiments thereof, include the same F polymers as those in the above-mentioned long laminated substrate and the method for producing the same.

[0282] The content of the F polymer in the polymer layer is preferably 50% by mass or more, more preferably 60% by mass or more. The upper limit of the content of the F polymer is 100% by mass.

[0283] The polymer layer may further include other resins in addition to the polymer F. The other resins may be thermosetting resins or thermoplastic resins.

[0284] Examples of the other resin, including preferred embodiments thereof, include the same other resins as those in the above-mentioned long laminated base material and the method for producing the same.

[0285] From the viewpoint of further improving the low linear expansion and electrical properties of the long laminated substrate, the polymer layer may further contain an inorganic filler.

[0286] Examples of the inorganic filler, including preferred embodiments thereof, include the same inorganic fillers as those in the above-mentioned long laminated substrate and the method for producing the same.

[0287] The content of the inorganic filler in the polymer layer may be, including the preferred range thereof, the same range as that of the inorganic filler in the above-mentioned long laminated substrate and the method for producing the same.

[0288] In addition to the above components, the polymer layer may also contain additives such as silane coupling agent, dehydrating agent, plasticizer, weathering agent, antioxidant, heat stabilizer, lubricant, antistatic agent, brightener, colorant, conductive agent, release agent, surface treatment agent, flame retardant, etc.

[0289] The polymer layer is preferably a layer of a sintered body containing particles of tetrafluoroethylene polymer, i.e., particles of F polymer. Hereinafter, particles of tetrafluoroethylene polymer are also referred to as "F particles". In addition, whether the polymer layer contains a sintered body of F particles can be confirmed by observing the cross section of the polymer layer using a microscope or the like.

[0290] When the polymer layer is a layer of a sintered body containing F particles, the gaps between the F particles serve as stress relaxation layers, making it easier to suppress the curling of the long laminated substrate.

[0291] When the polymer layer is a layer containing F particles, the polymer layer may contain components other than F particles. Components other than F particles include components other than the above-mentioned F polymers, specifically, resins other than F polymers, inorganic fillers, additives, etc.

[0292] D50 of the F particles may be, including a preferred range thereof, the same range as that of D50 of the F particles in the above-mentioned long laminated substrate and the method for producing the same.

[0293] The specific surface area of ​​the F particles is preferably 1 to 25 m 2 / g.

[0294] The F particles may be used alone or in combination of two or more.

[0295] The content of the F polymer in the F particles, including the preferred range thereof, may be the same range as the content of the F polymer in the F particles in the above-mentioned long laminated substrate and the method for producing the same.

[0296] The thickness of each of the two polymer layers is 12 to 40 μm, preferably 16 to 36 μm, and more preferably 20 to 33 μm from the viewpoint of dimensional stability of the laminated substrate.

[0297] The thickness of one of the two polymer layers is 0.9 to 1.1 times the thickness of the other polymer layer.

[0298] The total thickness of the two polymer layers is 1.8 to 3.0 times the thickness of the substrate, and more preferably 1.8 to 2.4 times from the viewpoint of suppressing curling of the long laminated substrate.

[0299] The total thickness of the long laminated substrate, i.e., the laminated thickness, is 36 μm or more, preferably 50 μm or more, and more preferably 75 μm or more from the viewpoint of dimensional stability of the laminated substrate. The total thickness of the long laminated substrate is 130 μm or less, and preferably 120 μm or less, and more preferably 100 μm or less from the same viewpoint.

[0300] From the viewpoint of dimensional stability of the laminated base material, the length in the short-side direction of the long laminated base material, that is, the width, is preferably 500 to 1250 mm.

[0301] The length of the long laminated substrate in the longitudinal direction is preferably 100 to 1000 m, more preferably 200 to 1000 m.

[0302] The length of the long laminated substrate in the longitudinal direction is preferably 50 times or more, more preferably 100 times or more, and preferably 1000 times or less, of the width of the long laminated substrate.

[0303] When the laminated substrate sheet cut from the long laminated substrate of 500 mm length is placed on a horizontal surface, the height of the laminated substrate sheet floating from the horizontal surface is preferably below 1 cm, more preferably below 0.5 cm. By making the floating height within the above range, the generation of wrinkles in the metal foil when the laminated substrate sheet is used to manufacture the metal-clad laminate can be suppressed compared with the case where the floating height is higher than the above range.

[0304] The floating height refers to the height of the position farthest from the horizontal plane in the floating portion of the laminated substrate sheet placed on the horizontal plane. In addition, the width of the laminated substrate sheet is the same as the width of the long laminated substrate.

[0305] <Method for producing long sheet roll>

[0306] A method for manufacturing a long sheet roll according to one embodiment includes: preparing a long laminated substrate, wherein the long laminated substrate has a substrate with a thickness of 12 to 50 μm and two polymer layers respectively arranged on both sides of the substrate, the two polymer layers contain F polymer and each has a thickness of 12 to 40 μm, the total thickness of the two polymer layers is 1.8 to 3.0 times the thickness of the substrate, and the thickness of one of the two polymer layers is 0.9 to 1.1 times the thickness of the other polymer layer; and winding the long laminated substrate on the outer peripheral surface of a cylindrical winding core, the curvature Cmm of the outer diameter of the winding core -1 The value of the product C×T of the total thickness Tmm of the long laminated base material is less than 0.0015.

[0307] The method for preparing the long laminated base material is not particularly limited, and the long laminated base material may be manufactured or used as it is.

[0308] The method for producing the long laminated substrate is not particularly limited, and may be a method in which a composition containing F particles and a liquid dispersion medium is coated on both sides of the substrate and heat treated (hereinafter also referred to as "method B1"), or a method in which films containing F polymers are laminated on both sides of the substrate.

[0309] The long laminated substrate is preferably produced by method B1. By producing by method B1, the two polymer layers formed are layers of a sintered body containing F particles, and curling of the long laminated substrate is easily suppressed.

[0310] An example of method B1 is described below.

[0311] In method B1, for example, first, by conveying the substrate while bringing the second surface of the substrate (hereinafter also referred to as "surface B2") into contact with the outer peripheral surface of the back roller, a composition containing F particles and a liquid dispersion medium is applied to the first surface of the substrate (hereinafter also referred to as "surface B1") and heat-treated to form a layer on surface B1 (hereinafter also referred to as "layer B1"). Next, by conveying the substrate while bringing layer B1 into contact with the outer peripheral surface of the back roller, the above-mentioned composition is applied to surface B2 and heat-treated to form a layer on surface B2 (hereinafter also referred to as "B2 layer"). Thereby, a long laminated substrate is obtained, which includes a substrate, a polymer layer containing an F polymer as a layer obtained by heat-treating layer B1, and a polymer layer containing an F polymer as layer B2.

[0312] Hereinafter, the polymer layer obtained by heat-treating layer B1 is also referred to as "P-B1 layer", and the polymer layer of layer B2 is also referred to as "P-B2 layer".

[0313] The composition applied on the surface of the substrate contains F particles and a liquid dispersion medium.

[0314] The details of the composition and the F particles in the composition, including preferred embodiments thereof, are the same as those in the above-mentioned long laminated substrate and the method for producing the same.

[0315] When forming a polymer layer containing components other than F particles (resins other than F polymers, inorganic fillers, additives, etc.), the composition may contain components other than the above-mentioned F particles.

[0316] The details of the resins other than the F polymer and the inorganic filler are already described above, and therefore their description is omitted.

[0317] The liquid dispersion medium, including its preferred embodiment, is the same as the liquid dispersion medium in the above-mentioned long multilayer substrate and the method for producing the same.

[0318] From the viewpoint of improving the dispersion stability of the F particles, the liquid dispersion medium preferably further contains a nonionic surfactant.

[0319] The nonionic surfactant, including preferred embodiments thereof, is the same as the nonionic surfactant in the above-mentioned long laminated substrate and the method for producing the same.

[0320] The embodiments including preferred embodiments of the content of the liquid dispersion medium, the solid content concentration in the composition, and the viscosity of the composition are the same as those in the embodiment of the above-mentioned long laminated substrate and the method for producing the same.

[0321] The composition may further contain additives such as thixotropy imparting agents, viscosity modifiers, defoaming agents, dehydrating agents, plasticizers, weathering agents, antioxidants, heat stabilizers, lubricants, antistatic agents, whitening agents, colorants, conductive agents, release agents, surface treatment agents, flame retardants, and various fillers represented by conductive fillers.

[0322] In order to adjust the viscosity of the composition to the above range, the liquid dispersion medium of the composition may contain a thickener.

[0323] The thickener may, for example, be a polyurethane thickener, a polyacrylic acid thickener, a polyamide thickener, a cellulose thickener or a thickener such as clay minerals such as bentonite.

[0324] When the liquid dispersion medium contains a thickener, the content of the thickener in the liquid dispersion medium may be in the range of 0.1 to 5 mass %.

[0325] The composition is obtained by mixing the F particles with other resins, inorganic fillers, liquid dispersion media, additives, etc. as required. The order of mixing is not particularly limited, and the mixing method may be a single mixing or a multiple mixing.

[0326] As a mixing device for obtaining the composition, the device in the above-mentioned long laminated substrate and the manufacturing method thereof can be mentioned.

[0327] As the method and conditions for applying the composition on the coating surface of the substrate, the coating method and conditions in the above-mentioned long laminated substrate and the method for producing the same may be mentioned.

[0328] As the method and conditions for heat-treating the composition layer formed by coating the composition on the coating surface of the substrate, the heat-treating method and conditions in the above-mentioned long laminated substrate and the method for producing the same may be mentioned.

[0329] Specifically, the heat treatment in the step of heat-treating the composition layer formed on the surface B1 of the substrate to form the layer B1 may be only a drying treatment, or only a calcining treatment, or a heat treatment including both a drying treatment and a calcining treatment after the drying treatment. That is, the layer B1 may be a layer in which the composition layer has been dried and the F particles are in an uncalcined state, or may be a P-B1 layer including a sintered body formed by calcining the F particles.

[0330] Specifically, after forming layer B1 on surface B1 of the substrate, the heat treatment in the step of forming layer B2 by heat treating the composition layer formed on surface B2 of the substrate may be only a calcination treatment, or a heat treatment including both a drying treatment and a calcination treatment performed after the drying treatment. The composition layer formed on surface B2 of the substrate is at least subjected to heat treatment, and a P-B2 layer as a B2 layer can be formed on surface B2 of the substrate.

[0331] In addition, when no sintering treatment is performed in the process of forming layer B1, that is, when the F particles of layer B1 are not sintered, layer B1 will also be sintered in the sintering treatment in the process of forming layer B2, obtaining a P-B1 layer containing a sintered body formed by sintered F particles.

[0332] The method of winding the long-length laminated base material on the outer peripheral surface of the winding core is not particularly limited.

[0333] The winding tension when winding the long laminated substrate around the outer peripheral surface of the winding core can be adjusted according to the stacking thickness of the long laminated substrate, and can be, for example, 30 to 200 N. From the viewpoint of suppressing winding deviation at the end of the long sheet roll, it is preferably 50 to 200 N.

[0334] The winding stress applied to the long laminated substrate when winding the long laminated substrate on the outer peripheral surface of the core is preferably 1 to 3 MPa, more preferably 1.5 to 2.5 MPa, and further preferably 1.7 to 2.3 MPa. By making the winding stress within the above range, the winding deviation of the long laminated substrate while being offset in the axial direction of the core is suppressed compared to the case where the winding stress is less than the above range. In addition, by making the winding stress within the above range, the curling of the long laminated substrate unwound from the roll sheet is suppressed compared to the case where the winding stress is greater than the above range.

[0335] The winding stress is a value obtained by dividing the measured winding tension by the cross-sectional area of ​​the long laminated substrate.

[0336] The long sheet roll of the present embodiment can be used, for example, for the production of a metal-clad laminate for producing a printed wiring board.

[0337] The details of the metal-clad laminate are the same as those of the metal-clad laminate in the above-mentioned long laminate base material and the method for producing the same.

[0338] Example

[0339] Hereinafter, embodiments of the present disclosure will be described in detail through examples, but the embodiments of the present disclosure are not limited thereto.

[0340] A1. Preparation of ingredients and components (Part 1)

[0341] Prepare the following materials and components.

[0342] [F polymer]

[0343] F polymer 1: a PFA-based polymer containing 98.0 mol%, 0.1 mol%, and 1.9 mol% of a TFE unit, a NAH unit, and a PPVE unit in that order (melting point: 300°C)

[0344] F polymer 2: a PFA-based polymer containing 97.5 mol% and 2.5 mol% of TFE units and PPVE units, respectively (melting point: 305°C)

[0345] In addition, for every 1×10 6 The main chain carbon number has 1000 carbonyl groups, and the polymer F2 has 1×10 6 The main chain carbon number has 40 carbonyl-containing groups.

[0346] [F particles]

[0347] F particles 1: particles composed of F polymer 1 with a D50 of 2.1 μm

[0348] F particles 2: particles composed of F polymer 2 with a D50 of 1.8 μm

[0349] [Surfactant]

[0350] Surfactant 1: nonionic surfactant, polyether-modified polydimethylsiloxane, product name: BYK-3450, manufactured by BYK Chemical Japan Co., Ltd.

[0351] [Thickener]

[0352] Thickener 1: Hydroxymethylcellulose, product name: HEC-1, manufactured by Sumitomo Seika Chemicals Co., Ltd.

[0353] [Base material]

[0354] Polyimide film 1: an aromatic polyimide film having a thickness of 34 μm, a width of 520 mm, a length in the longitudinal direction of 500 m, a glass transition temperature of 245° C., and a tensile elastic modulus at 320° C. of 0.3 GPa.

[0355] A2. Preparation of Compositions (Compositions A1 to A3)

[0356] F particles, surfactant 1, thickener 1, and water shown in Table 1 were added to a can in the amounts (parts by mass) shown in Table 1, and zirconium oxide balls were added. The can was then rolled at 150 rpm for 1 hour to prepare compositions A1 to A3 shown in Table 1.

[0357] The viscosity of the obtained composition and the surface tension of the liquid dispersion medium were measured by the above-mentioned method. The measurement results are shown in Table 1 together.

[0358] [Table 1]

[0359]

[0360] A3. Production and Measurement of Long Laminated Substrate (Examples A1 to A7)

[0361] Use with Figure 2 The apparatus of the coating section shown in the figure was used, and the above-mentioned polyimide film 1 was used as the substrate 12, and polymer layers were formed on both surfaces of the polyimide film 1.

[0362] Specifically, first, the second surface of the polyimide film 1 is brought into contact with the outer peripheral surface of the backing roll 20 whose outer peripheral surface Rzjis is the value shown in Table 2, so that the contact surface pressure is the value shown in Table 2. Then, while the polyimide film 1 is conveyed, the composition shown in Table 2 is coated on the first surface of the polyimide film 1 by a slit coating method, and the film is passed through a ventilation drying furnace (furnace temperature: 150° C.) for 3 minutes to remove water to form a dry film, i.e., the first layer.

[0363] Next, the polyimide film 1 is conveyed while the first layer is in contact with the outer peripheral surface of the backing roller 20, the composition is applied to the second surface of the polyimide film 1, and the film is passed through a ventilated drying oven (oven temperature: 150° C.) for 3 minutes to remove water to form a second dry film. The backing roller 20, contact surface pressure, conveying speed, type of composition, and coating conditions of the composition used in the formation of the second dry film are the same as those used in the formation of the first layer.

[0364] Next, the polyimide film 1 with dry films formed on both sides was passed through a far-infrared furnace (furnace temperature 300°C near the inlet and outlet, furnace temperature 340°C near the center) for 20 minutes to melt and sinter the F particles contained in the composition to form a sintered body of the F particles.

[0365] In this way, polymer layers containing F polymer are formed on both sides of the polyimide film 1, and the first layer of the sintered body, namely the P-A1 layer (thickness: 33μm), the polyimide film 1, namely the substrate (thickness: 34μm), and the second layer of the sintered body of the dried film, namely the P-A2 layer (thickness: 33μm) are directly formed in sequence to obtain a long strip of laminated substrate with a width of 520mm and a length of 500m in the long side direction.

[0366] As described above, long laminated substrates of Examples A1 to A7 were obtained.

[0367] For the exposed surface of the two polymer layers in the obtained long laminated substrate, the above-mentioned measurement based on the white light interference method and the calculation of Sdq were performed at 10 locations, and the average was taken to obtain the Sdq of the P-A1 layer and the Sdq of the P-A2 layer. The results are shown in Table 2.

[0368] The obtained long laminated substrate was wound around a cylindrical winding core (material: ABS resin, outer diameter: 152 mm, curvature: 0.033 mm). -1 , axial length: 520mm, thickness: 8mm) and made into a roll sheet.

[0369] A4. Evaluation of long laminated substrate (copper foil peeling evaluation)

[0370] After unwinding 100m of the long strip laminated substrate from the roll sheet of Examples A1 to A7 and cutting it, further unwinding 1m of the long strip laminated substrate and cutting it, a laminated substrate of 520mm×1000mm was obtained, copper was deposited on the entire surface of both sides of the laminated substrate by sputtering, and the thickness of each copper layer was 12μm by copper sulfate plating to obtain a copper-clad laminate. Then, the copper-clad laminate cut into 5cm squares was floated on the molten solder in a solder tank at 260°C, taken out after 10 seconds, visually confirmed the appearance, and copper foil isolation was evaluated according to the following evaluation criteria. The results are shown in Table 2.

[0371] <Evaluation Criteria>

[0372] A: No copper floating or peeling was observed.

[0373] B: Micro-floating of copper was observed.

[0374] C: A portion where copper was completely peeled off was observed.

[0375] [Table 2]

[0376]

[0377] In the above examples, Examples A1 to A3 are Examples, and Examples A4 to A7 are Comparative Examples. As shown in Table 2, in Examples A1 to A3, Sdq was 5 μm / mm or less, and the peeling of the metal foil was suppressed compared to Examples A4 to A7 where Sdq exceeded 5 μm / mm.

[0378] In Examples A4 and A7, it was confirmed that a stick-slip phenomenon occurred during application of the composition.

[0379] B1. Preparation of ingredients and components (Part 2)

[0380] Prepare the following materials and components.

[0381] [F polymer]

[0382] F polymer 1: a PFA-based polymer containing 98.0 mol%, 0.1 mol%, and 1.9 mol% of a TFE unit, a NAH unit, and a PPVE unit in that order (melting point: 300°C)

[0383] In addition, in F polymer 1, for every 1×10 6 The main chain carbon number has 1000 carbonyl-containing groups.

[0384] [F particles]

[0385] F particles 1: particles composed of F polymer 1 and having a D50 of 2.1 μm.

[0386] [Surfactant]

[0387] Surfactant 1: nonionic surfactant, polyether-modified polydimethylsiloxane, product name: BYK-3450, manufactured by BYK Chemical Japan Co., Ltd.

[0388] [Thickener]

[0389] Thickener 1: Hydroxymethylcellulose, product name: HEC-1, manufactured by Sumitomo Seika Chemicals Co., Ltd.

[0390] [Base material]

[0391] Polyimide film 1: an aromatic polyimide film having a thickness of 34 μm, a width of 520 mm, a length in the longitudinal direction of 500 m, a glass transition temperature of 245° C., and a tensile elastic modulus at 320° C. of 0.3 GPa.

[0392] Polyimide film 2: an aromatic polyimide film having a thickness of 17 μm, a width of 520 mm, a length in the longitudinal direction of 500 m, a glass transition temperature of 245° C., and a tensile elastic modulus at 320° C. of 0.3 GPa.

[0393] [Core]

[0394] Core 1: Made of ABS resin, outer diameter 168mm, curvature 0.0119mm -1 , a cylindrical winding core with an axial length of 520mm and a thickness of 8mm.

[0395] Core 2: Made of ABS resin, outer diameter 92mm, curvature 0.0217mm -1 , a cylindrical winding core with an axial length of 520mm and a thickness of 8mm.

[0396] B2. Preparation of Composition

[0397] 50 parts by mass of F particles 1, 2.5 parts by mass of surfactant 1, 0.5 parts by mass of thickener 1 and 47 parts by mass of water were placed in a pot, and zirconium oxide balls were placed therein, and then the pot was rolled at 150 rpm for 1 hour to prepare a composition.

[0398] B3. Production of Long Laminated Base Material (Long Laminated Base Materials 1 to 2)

[0399] The surface B2 of the polyimide film 1 is brought into contact with the outer peripheral surface of the back roller, and the above-mentioned composition is applied to the surface B1 of the polyimide film 1 by a slit coating method while the polyimide film 1 is conveyed. The film is passed through a ventilated drying furnace (furnace temperature 150°C) for 3 minutes to remove water and form a dry film, i.e., layer B1.

[0400] Next, the polyimide film 1 was conveyed while the layer B1 was in contact with the outer peripheral surface of the backing roll, and the composition was applied to the surface B2 of the polyimide film 1 and passed through a ventilation drying oven (oven temperature 150° C.) for 3 minutes to remove water to form a dry film B2.

[0401] Next, the polyimide film 1 with dry films formed on both sides is passed through a far-infrared furnace (furnace temperature 300°C near the inlet and outlet, furnace temperature 340°C near the center) for 20 minutes to melt and sinter the F particles contained in the composition to form a sintered body of the F particles.

[0402] In this way, a polymer layer containing F polymer is formed on both sides of the polyimide film 1, and the sintered body of layer B1, i.e., the P-B1 layer (thickness: 33 μm), the polyimide film 1, i.e., the substrate (thickness: 34 μm), and the sintered body of the dried film B2, i.e., the P-B2 layer (thickness: 33 μm) are directly formed in sequence to obtain a long strip laminated substrate with a laminate thickness of 100 μm.

[0403] As described above, a long laminated substrate 1 is obtained.

[0404] The same operation as the long laminated substrate 1 was performed except that the polyimide film 2 was used instead of the polyimide film 1 and the thickness of the P-B1 layer and the P-B2 layer were set to 16.5 μm respectively, thereby obtaining a long laminated substrate 2 with a laminate thickness of 50 μm.

[0405] B4. Manufacturing and Measurement of Long Sheet Coils (Examples B1 to B5)

[0406] The long laminated substrate shown in Table 3 was wound around the winding core shown in Table 3 at the winding tension shown in Table 3 to produce a long sheet roll. Table 3 shows the winding stress applied to the long laminated substrate during winding together with the product C×T.

[0407] After unwinding 450 m of the long sheet roll of Examples B1 to B5 and cutting it, unwinding 500 mm of the long sheet roll and cutting it to obtain a 520 mm × 500 mm laminated substrate sheet, which was placed on a horizontal surface. The height of the substrate sheet floating from the horizontal surface was measured, and the curling was evaluated according to the following criteria. The results are shown in Table 3.

[0408] A: The floating height is less than 0.5cm

[0409] B: The floating height is greater than 0.5cm and less than 1cm

[0410] C: Floating height greater than 1cm

[0411] The winding deviation of the end of the long sheet roll in Examples B1 to B5 was measured with a steel ruler. Specifically, the distance from the axial front end of the core in the width direction of the long laminated substrate was taken as the "winding deviation", and the winding deviation was evaluated according to the following criteria. The results are shown in Table 3.

[0412] A: Winding deviation is less than 1cm

[0413] B: The winding deviation is more than 1cm and less than 2cm

[0414] C: Winding deviation is more than 2cm

[0415] B5. Evaluation of long sheet rolls (copper foil wrinkle evaluation)

[0416] The long laminated substrate continuously unwound from the long sheet roll in Examples B1 to B5 and the copper foil unwound from another unwinding section in parallel were laminated by applying pressure while passing between two heated rollers. The long strip of copper-clad laminate was continuously wound in this state to produce the long strip. The appearance was visually evaluated and the copper foil wrinkles were evaluated according to the following criteria. The results are shown in Table 3.

[0417] A: No wrinkles on the copper foil are observed on the appearance of the long strip of copper-clad laminate.

[0418] B: Wrinkles of copper foil can be seen at the ends of the long strip of copper-clad laminate in the width direction.

[0419] C: Folding wrinkles of the copper foil due to the curling of the long laminated substrate can be seen in the center of the width direction of the copper-clad laminate.

[0420] [Table 3]

[0421]

[0422] In the above examples, Examples B1 to B3 are examples, and Example B5 is a comparative example. As shown in Table 3, in Examples B1 to B4, the occurrence of curling is suppressed compared to Example B5 where the product C×T is 0.0015 or more, and wrinkles of the metal foil caused by curling are suppressed.

[0423] The disclosures of Japanese Patent Application No. 2022-090871 filed on June 3, 2022 and Japanese Patent Application No. 2022-090872 filed on June 3, 2022 are incorporated herein by reference in their entirety. In addition, all documents, patent applications, and technical standards described in this specification are incorporated herein by reference to the same extent as if the portions incorporated by reference in each document, patent application, and technical standard were specifically and separately described.

[0424] Explanation of symbols

[0425] 10 Long strip laminated substrate

[0426] 12. Substrate

[0427] 14, 16 Polymer layer

[0428] 14S, 16S exposed

[0429] 20 Back Roller

[0430] 22 Coating components

[0431] 26 Combination Layer

[0432] 100 long sheet rolls

[0433] 120 core. < / b8> < / b8> < / b8> < / b8> < / b1> < / b1> < / b1> < / b1> < / a9> < / a9> < / a9> < / a9> < / a9> < / a9> < / a9> < / a1> < / a1> < / a1> < / a1> < / a1>

Claims

1. A long laminated substrate, comprising a substrate having a thickness of 12 to 50 μm and two polymer layers respectively arranged on both sides of the substrate, wherein the two polymer layers contain a tetrafluoroethylene polymer and each has a thickness of 12 to 40 μm, and the value of the root mean square slope Sdq measured on the surface opposite to the substrate in accordance with ISO25178-2:2012 is less than 5 μm / mm.

2. The long laminate substrate according to claim 1, wherein The substrate includes at least one selected from polyimide, liquid crystal polyester and polytetrafluoroethylene.

3. The long laminate substrate according to claim 1, wherein The two polymer layers are layers containing a sintered body of particles of the tetrafluoroethylene-based polymer.

4. The long laminate substrate according to claim 1, wherein The total thickness of the two polymer layers is 1.8 to 3.0 times the thickness of the substrate, and the thickness of one of the two polymer layers is 0.9 to 1.1 times the thickness of the other polymer layer.

5. The long laminate substrate according to claim 1, wherein The tetrafluoroethylene polymer has a melting point of 260 to 320°C.

6. A method for manufacturing a long laminated substrate, comprising: The first layer is formed on the first surface of the substrate by coating a composition containing particles of a tetrafluoroethylene polymer and a liquid dispersion medium on the first surface of the substrate while the second surface of the substrate having a thickness of 12 to 50 μm is brought into contact with the outer peripheral surface of a backing roller having an outer peripheral surface ten-point average roughness Rzjis of 0.5 to 10 μm under a contact surface pressure of 100 to 3000 kPa, and conveying the substrate; and The substrate is conveyed while the first layer is brought into contact with the outer peripheral surface of the backing roll at a contact surface pressure of 100 to 3000 kPa, the composition is applied to the second surface and heat-treated to form a second layer on the second surface, A long laminated substrate including the substrate, a first polymer layer including the tetrafluoroethylene polymer and having a thickness of 12 to 40 μm, and a second polymer layer including the tetrafluoroethylene polymer and having a thickness of 12 to 40 μm is obtained.

7. The manufacturing method according to claim 6, wherein: The ten-point average roughness Rzjis of the outer peripheral surface of the backing roller is 0.5 to 8 μm.

8. The manufacturing method according to claim 6, wherein: The contact surface pressure is 250-2000 kPa.

9. The manufacturing method according to claim 6, wherein: The surface tension of the liquid dispersion medium is 20 to 30 mN / m.

10. A long sheet roll comprising a cylindrical core and a long laminated substrate wound around the outer peripheral surface of the core, The long laminated substrate comprises a substrate with a thickness of 12 to 50 μm and two polymer layers respectively arranged on both sides of the substrate, wherein the two polymer layers contain tetrafluoroethylene polymers and each has a thickness of 12 to 40 μm. The total thickness of the two polymer layers is 1.8 to 3.0 times the thickness of the substrate, and the thickness of one of the two polymer layers is 0.9 to 1.1 times the thickness of the other polymer layer. The curvature of the outer diameter of the winding core is Cmm -1 The value of the product C×T of the total thickness Tmm of the long laminated base material is less than 0.0015.

11. The long sheet roll according to claim 10, wherein: The two polymer layers are layers containing a sintered body of particles of the tetrafluoroethylene-based polymer.

12. The long sheet roll according to claim 10, wherein: The tetrafluoroethylene polymer has a melting point of 260 to 320°C.

13. The long sheet roll according to claim 10, wherein: When the long laminated substrate is unwound by 500 mm and the cut laminated substrate sheet is placed on a horizontal surface, the height of the laminated substrate sheet floating from the horizontal surface is 1 cm or less.

14. A method for manufacturing a long sheet roll, comprising: Preparing a long laminated substrate, wherein the long laminated substrate comprises a substrate having a thickness of 12 to 50 μm and two polymer layers respectively disposed on both sides of the substrate, the two polymer layers comprising a tetrafluoroethylene polymer and each having a thickness of 12 to 40 μm, the total thickness of the two polymer layers being 1.8 to 3.0 times the thickness of the substrate, and the thickness of one of the two polymer layers being 0.9 to 1.1 times the thickness of the other polymer layer; and The long laminated substrate is wound around the outer peripheral surface of a cylindrical winding core, The curvature of the outer diameter of the winding core is Cmm -1 The value of the product C×T of the total thickness Tmm of the long laminated base material is less than 0.0015.

15. The manufacturing method according to claim 14, wherein: The winding stress when the long-length laminated substrate is wound around the outer peripheral surface of the winding core is 1 to 3 MPa.

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