WO2022210197A1

WO2022210197A1 - Laminate and method for manufacturing same

Info

Publication number: WO2022210197A1
Application number: PCT/JP2022/013674
Authority: WO
Inventors: 絢子加藤; 浩成摺出寺
Original assignee: 日本ゼオン株式会社
Priority date: 2021-03-30
Filing date: 2022-03-23
Publication date: 2022-10-06
Also published as: TW202248016A; JPWO2022210197A1

Abstract

The present invention provides a laminate that comprises a substrate and a protective film provided on one of the surfaces of the substrate, and that has an elongated shape. The substrate is a layer of a resin including a crystalline alicyclic-structure-containing polymer. The substrate and the protective film satisfy the relationships E's/E'p<1 and -0.4≤Fs-Fp≤0.4. In the aforementioned relationships, E's is the storage modulus of the substrate at 180°C, E'p is the storage modulus of the protective film at 180°C, Fs is the heat shrinkage rate (%) of the substrate in the longitudinal direction of the laminate for 2 minutes at 180°C, and Fp is the heat shrinkage rate (%) of the protective film in the longitudinal direction of the laminate for 2 minutes at 180°C. The present invention also provides a method for manufacturing a laminate, the method including a process for annealing a pre-annealing laminate.

Description

Laminate and its manufacturing method

The present invention relates to a laminate comprising a base material that can be used as an optical film or the like and a protective film that protects the base material, and a method for producing the same.

Optical films are widely used as components of optical devices such as liquid crystal display devices and organic electroluminescence display devices. Examples include films used as substrates in devices. Specifically, it is common practice to form other layers on such a base material to obtain a component comprising a plurality of layers constituting a device.

Optical films are required to have good optical properties and high durability against heat in the usage environment. For example, even when subjected to a heat load such as heating at 200° C. for 10 minutes or heating at 145° C. for 60 minutes, it is desirable not to cause shape change such as shrinkage.

From such a point of view, a crystalline resin, particularly a resin containing a crystalline alicyclic structure-containing polymer, may be used as a material for such an optical film. When using a resin having such crystallinity, various treatments such as stretching and heat setting may be performed in order to adjust optical anisotropy, heat resistance and other various properties (for example, Patent Document 1 ~2).

International Publication No. 2016/067893 (corresponding publication: US Patent Application Publication No. 2017/306113) Japanese Patent Application Laid-Open No. 2021-24086

When processing a crystalline resin film, wrinkles may occur on the surface, causing undesirable phenomena such as damage to the flatness of the film, which may reduce the quality of the product. Moreover, depending on the method of processing, the optical film may not have sufficient heat resistance. For example, it may not be possible to suppress shape change when subjected to a heat load such as heating at 200° C. for 10 minutes or heating at 145° C. for 60 minutes.

Accordingly, an object of the present invention is to provide a base material that suppresses the occurrence of wrinkles, maintains flatness when used as a base material, and has high heat resistance, and a method for producing the same.

As a measure for suppressing the generation of wrinkles and maintaining flatness when used as a base material, it is conceivable to make the base material a laminate with a protective film. As a result of investigations by the present inventors on this point, it was found that high wrinkle suppression and heat resistance can be obtained by adopting a substrate and a protective film that have a specific physical property relationship to form a laminate. It was found that such a laminate can be produced by laminating a specific pre-annealing base material and a pre-annealing protective film to form a pre-annealing laminate, which is then annealed in the state of the laminate. The inventors found that it can be obtained, and completed the present invention.
That is, the present invention provides the following.

[1] A laminate having a long shape, comprising a substrate and a protective film provided on one surface of the substrate,
The substrate is a resin layer containing a crystalline alicyclic structure-containing polymer,
A laminate in which the substrate and the protective film satisfy the following formulas (1) to (2):
E's/E'p<1 (1)
-0.4≤Fs-Fp≤0.4 (2)
however,
E's is the storage modulus of the base material at 180°C,
E'p is the storage modulus of the protective film at 180°C,
Fs is the thermal shrinkage rate (%) of the base material in the longitudinal direction of the laminate at 180 ° C. for 2 minutes,
Fp is the heat shrinkage rate (%) of the protective film in the longitudinal direction of the laminate at 180° C. for 2 minutes.
[2] The laminate according to [1], wherein the protective film is a resin layer containing a crystalline polymer.
[3] The resin according to [1] or [2], wherein the resin containing the crystalline alicyclic structure-containing polymer constituting the base material is a hydride of a ring-opening polymer of dicyclopentadiene. laminate.
[4] A method for producing a laminate according to any one of [1] to [3],
A step of bonding a pre-annealed base material and a pre-annealed protective film to obtain a pre-annealed laminate comprising the pre-annealed base material and the pre-annealed protective film, wherein the pre-annealed base material is a crystalline fat. A production method comprising: a step of forming a resin layer containing a cyclic structure-containing polymer; and a step of annealing the pre-annealed laminate.
[5] The production method of [4], wherein the pre-annealing protective film is a resin layer containing a crystalline polymer.
[6] to [4] or [5], wherein the resin containing the crystalline alicyclic structure-containing polymer constituting the base material before annealing is a hydride of a ring-opening polymer of dicyclopentadiene; Method of manufacture as described.
[7] Any one of [4] to [6], wherein the annealing includes heating the pre-annealed laminate while restraining it in at least one of its in-plane directions. Method of manufacture as described.

According to the present invention, a laminate that suppresses the occurrence of wrinkles, maintains flatness when used as a substrate, and can easily supply a substrate with high heat resistance at the time of use, and a method for producing the same are provided. be done.

FIG. 1 is a cross-sectional view schematically showing the laminate of the present invention.

Hereinafter, the present invention will be described in detail by showing embodiments and examples. However, the present invention is not limited to the embodiments and examples shown below, and can be arbitrarily modified without departing from the scope of the claims of the present invention and their equivalents.

In the following description, the term "long-shaped" film refers to a film having a length of 5 times or more, preferably 10 times or more, of its width. A film that is long enough to be wound into a roll and stored or transported. The upper limit of the length of the film is not particularly limited, and can be, for example, 100,000 times or less the width.

Unless otherwise specified, the adhesive is not only an adhesive in a narrow sense (an adhesive having a shear storage elastic modulus of 1 MPa to 500 MPa at 23 ° C. after energy beam irradiation or after heat treatment), but also shear storage at 23 ° C. Adhesives with an elastic modulus of less than 1 MPa are also included.

In the following description, the terms “parallel”, “perpendicular” and “perpendicular” in the directions of the elements are within a range that does not impair the effects of the present invention, such as ±3°, ±2° or ±1°, unless otherwise specified. may contain an error within the range of

[Outline of laminate]
The laminate of the present invention comprises a substrate and a protective film provided on one surface of the substrate. That is, the laminate includes a substrate and a protective film as layers constituting the laminate.

The base material is a film for use as a component of optical devices such as display devices. On the other hand, a protective film is a film that is attached to a substrate for the purpose of protecting the substrate, and that can be peeled off when the substrate is used for manufacturing a device or in any subsequent process.

Although the protective film may be provided in direct contact with the base material, it is usually provided on the base material via an adhesive layer. That is, the base material and the protective film are adhered via the adhesive layer, thereby forming a laminate in which the base material, the adhesive layer and the protective film layer are provided in this order.

FIG. 1 is a cross-sectional view schematically showing the laminate of the present invention. In FIG. 1 , the laminate 10 includes a base material 110 and a composite film 120 provided on one surface thereof, and the composite film includes a protective film 121 and an adhesive layer 122 . In this example, the protective film is provided only on one of the front surface and the back surface of the substrate, but the present invention is not limited to this. A film may be provided.

In FIG. 1, the protective film 121 is a layer for exhibiting mechanical strength and other desired physical properties as a protective film, while the adhesive layer 122 exhibits the function of adhesion between the substrate 110 and the protective film 121. layer. The adhesive layer 122 is generally thinner and more flexible than the protective film 121, and therefore does not substantially affect the mechanical strength of the composite film 120 as a whole with respect to the in-plane expansion and contraction.

The base material is a resin layer containing a crystalline alicyclic structure-containing polymer. In the following description, the resin may be particularly referred to as resin (a1) in order to distinguish it from common resins. On the other hand, the resin that constitutes the protective film may be particularly referred to as resin (b1).

In the laminate, the base material may be a single-layer structure layer or a multi-layer structure layer consisting of a plurality of layers, but is usually a single-layer structure layer. The protective film may also be a layer having a single layer structure, or a layer having a multi-layer structure consisting of a plurality of layers, but is usually a layer having a single layer structure.

[Physical properties of laminate]
The base material and protective film constituting the laminate satisfy the following formulas (1) and (2).
E's/E'p<1 (1)
-0.4≤Fs-Fp≤0.4 (2)

In the formula, E's is the storage modulus of the substrate at 180°C, and E'p is the storage modulus of the protective film at 180°C. In the following description, elastic modulus means storage elastic modulus unless otherwise specified. The value of E's/E'p is less than 1, preferably 0.95 or less, more preferably 0.90 or less. Although the lower limit of E's/E'p is not particularly limited, it can be 0.1 or more. Each value of E's and E'p is not particularly limited, but can be, for example, 1.0×10 ⁷ Pa or more and 1.0×10 ⁹ Pa or less. The elastic modulus is measured by peeling off the base material and the protective film of the laminate, using each as a sample film, and using a dynamic viscoelasticity measuring device (for example, manufactured by Hitachi High-Tech Science Co., Ltd., product name: DMA7100) at 180 ° C. It can be measured by stretching viscoelasticity measurement.

In the formula, Fs is the heat shrinkage rate of the base material in the longitudinal direction of the laminate at 180°C for 2 minutes, and Fp is the heat shrinkage rate of the protective film in the laminate longitudinal direction at 180°C for 2 minutes. Fs and Fp are the thermal shrinkage ratios of the laminate. It is a percentage value obtained by measuring the change in the length of a side of a square sample film having parallel sides when the sample film is heated. More specifically, the thermal shrinkage rate can be obtained according to the following formula (I).
Thermal shrinkage rate (%) = [(L _B -L _A )/L _B ]×100 (I)

In the formula, LB indicates the _side length of the sample film before heating, and _LA indicates the side length of the sample film after heating. A positive value of heat shrinkage indicates that the film shrinks due to heating, and a negative value indicates that the film elongates due to heating. When determining the thermal shrinkage in the longitudinal direction of the laminate, the thermal shrinkage is determined from the length of the side of the sample film parallel to the longitudinal direction of the laminate.

The value of Fs-Fp is the value of the difference between the percentages. The value of Fs-Fp is -0.4% or more, preferably -0.3% or more, while it is 0.4% or less, preferably 0.3% or less. Each value of Fs and Fp is not particularly limited, but can be, for example, -0.3% or more and 0.5% or less.

According to the findings of the present inventors, the long laminate comprises a base material that is a layer of the resin (a1) and a protective film, and the base material and the protective film have the above formulas (1) to When (2) is satisfied, the occurrence of wrinkles in the laminate can be suppressed, the laminate can be handled while maintaining its flatness, and the substrate can be easily manufactured as a substrate with high heat resistance. It can be done. Specifically, the curling of the laminate can be suppressed, so that the laminate can be conveyed in a state where it is not curled, and the 200 ° C. 10 minute substrate heat shrinkage rate of the obtained substrate and Physical properties, such as base material heat shrinkage at 145° C. for 60 minutes, which are required to be low as a product, can also be set to favorable low values.

The laminate of the present invention preferably has a small amount of curl. The amount of curl was determined by cutting the laminate into a 50 mm × 50 mm square sample film under an environment of 23 ° C. (room temperature), placing it on a horizontal and flat surface, and raising the four corners of the sample film from the horizontal surface. It is obtained by measuring the amount (amount of curl) and calculating the average value of the four corners. The amount of curl can be preferably 8.5 mm or less, more preferably 7.5 mm or less. Although the lower limit of curl amount is not particularly limited, it is ideally 0.0 mm.

〔Base material〕
The substrate is a layer of resin (a1), that is, a resin layer containing a crystalline alicyclic structure-containing polymer. The base material can be a layer consisting only of the resin (a1). By using the resin (a1) as the base material, the base material can exhibit good mechanical strength, heat resistance, and moldability.

A polymer that "has crystallinity" refers to a polymer that has a melting point Tm. "Have a melting point Tm" means that the melting point can be observed with a differential scanning calorimeter (DSC). In the following description, a polymer having crystallinity may be simply referred to as a "crystalline polymer". Also, a resin containing a polymer having crystallinity may be simply referred to as a “crystalline resin”. The alicyclic structure-containing polymer is a polymer containing an alicyclic structure in the molecule. It is a polymer containing structures.

The alicyclic structure-containing polymer can be a polymer or a hydride thereof that can be obtained by a polymerization reaction using a cyclic olefin as a monomer. One type of the alicyclic structure-containing polymer may be used alone, or two or more types may be used in combination at an arbitrary ratio.

Examples of the alicyclic structure possessed by the alicyclic structure-containing polymer include a cycloalkane structure and a cycloalkene structure. Among these, a cycloalkane structure is preferable because an optical film having excellent properties such as thermal stability can be easily obtained. The number of carbon atoms contained in one alicyclic structure is preferably 4 or more, more preferably 5 or more, preferably 30 or less, more preferably 20 or less, and particularly preferably 15 or less. be. When the number of carbon atoms contained in one alicyclic structure is within the above range, mechanical strength, heat resistance, and moldability are highly balanced.

In the alicyclic structure-containing polymer, the ratio of structural units having an alicyclic structure to all structural units is preferably 30% by weight or more, more preferably 50% by weight or more, and particularly preferably 70% by weight or more. . Heat resistance can be improved by increasing the ratio of structural units having an alicyclic structure in the alicyclic structure-containing polymer as described above.
In addition, in the alicyclic structure-containing polymer, the remainder other than structural units having an alicyclic structure is not particularly limited and can be appropriately selected according to the purpose of use.

Examples of the crystalline alicyclic structure-containing polymer include the following polymers (α) to (δ). Among these, the polymer (β) is preferable as the crystalline alicyclic structure-containing polymer because a base material having excellent heat resistance can be easily obtained.
Polymer (α): A ring-opening polymer of a cyclic olefin monomer and having crystallinity.
Polymer (β): A hydride of polymer (α) and having crystallinity.
Polymer (γ): A crystalline addition polymer of cyclic olefin monomers.
Polymer (δ): A hydride or the like of polymer (γ) having crystallinity.

Specifically, the crystalline alicyclic structure-containing polymer includes a ring-opening polymer of dicyclopentadiene having crystallinity, and a hydride of a ring-opening polymer of dicyclopentadiene. It is more preferable to have crystallinity, and particularly preferable is a hydrogenated ring-opening polymer of dicyclopentadiene having crystallinity. Here, the ring-opening polymer of dicyclopentadiene means that the ratio of structural units derived from dicyclopentadiene to all structural units is usually 50% by weight or more, preferably 70% by weight or more, more preferably 90% by weight or more, More preferably, it refers to 100% by weight of polymer.

The hydride of the ring-opening polymer of dicyclopentadiene preferably has a high ratio of racemo dyads. Specifically, the ratio of the racemo diad of repeating units in the hydrogenated ring-opening polymer of dicyclopentadiene is preferably 51% or more, more preferably 70% or more, and particularly preferably 85% or more. A high proportion of racemo dyads indicates high syndiotactic stereoregularity. Therefore, the melting point of the hydride of the ring-opening polymer of dicyclopentadiene tends to be higher as the ratio of the racemo diad is higher. The ratio of racemo dyads can be determined based on the ¹³ C-NMR spectrum analysis described in the Examples below.

As the crystalline alicyclic structure-containing polymer, a polymer obtained by the production method disclosed in International Publication No. 2018/062067 can be used.

The melting point Tm of the crystalline alicyclic structure-containing polymer is preferably 200°C or higher, more preferably 230°C or higher, and preferably 290°C or lower. By using a crystalline polymer having such a melting point Tm, it is possible to obtain a substrate having a better balance between moldability and heat resistance.

Usually, a crystalline polymer such as a crystalline alicyclic structure-containing polymer has a glass transition temperature Tg. Although the specific glass transition temperature Tg of the crystalline polymer is not particularly limited, it is usually 85°C or higher and usually 170°C or lower.

The glass transition temperature Tg and melting point Tm of the polymer can be measured by the following methods. First, the polymer is melted by heating, and the melted polymer is quenched with dry ice. Subsequently, using this polymer as a test sample, a differential scanning calorimeter (DSC) was used to measure the glass transition temperature Tg and melting point Tm of the polymer at a heating rate of 10° C./min (heating mode). measurable.

The weight-average molecular weight (Mw) of the crystalline polymer such as a crystalline alicyclic structure-containing polymer is preferably 1,000 or more, more preferably 2,000 or more, and preferably 1,000,000. 500,000 or less, more preferably 500,000 or less. A crystalline polymer having such a weight-average molecular weight has an excellent balance between moldability and heat resistance.

The molecular weight distribution (Mw/Mn) of the crystalline polymer such as a crystalline alicyclic structure-containing polymer is preferably 1.0 or more, more preferably 1.5 or more, and preferably 4.0 or less. , more preferably 3.5 or less. Here, Mn represents the number average molecular weight. A crystalline polymer having such a molecular weight distribution is excellent in moldability. The weight average molecular weight (Mw) and molecular weight distribution (Mw/Mn) of the crystalline polymer can be measured as polystyrene equivalent values by gel permeation chromatography (GPC) using tetrahydrofuran as a developing solvent.

The proportion of the crystalline alicyclic structure-containing polymer in the resin (a1) is preferably 50% by weight or more, more preferably 70% by weight or more, and particularly preferably 90% by weight or more. By setting the ratio of the crystalline alicyclic structure-containing polymer to at least the lower limit of the above range, the heat resistance of the substrate can be effectively increased. The upper limit of the proportion of crystalline polymer can be 100% by weight or less.

The crystalline alicyclic structure-containing polymer contained in the resin (a1) does not have to be crystallized before manufacturing the base material. However, in the state where the base material is formed in the laminate of the present invention, the crystalline polymer contained in the base material is preferably crystallized, and preferably has a high degree of crystallinity. By having a high degree of crystallinity, the effects of the present invention, such as heat resistance, can be exhibited more favorably. A specific crystallinity range is preferably 20% or higher, more preferably 25% or higher, and particularly preferably 30% or higher. Although the upper limit of the crystallinity is not particularly limited, it can be 95% or less. The degree of crystallinity of a crystalline polymer can be measured by a density method, an X-ray diffraction method, or a measurement method using a differential scanning calorimeter.

The resin (a1) may contain any component in addition to the crystalline alicyclic structure-containing polymer. Examples of optional ingredients include antioxidants; light stabilizers; waxes; nucleating agents; fluorescent brighteners; near-infrared absorber; lubricant; filler; and any polymer other than crystalline polymer; Moreover, arbitrary components may be used individually by 1 type, and may be used in combination of 2 or more types by arbitrary ratios.

The thickness of the substrate is preferably 5 µm or more, more preferably 10 µm or more, and preferably 160 µm or less, more preferably 150 µm or less.

〔Protective film〕
The resin (b1), i.e., the resin constituting the protective film in the protective film, may have a resin layer containing a crystalline polymer from the viewpoint of easily obtaining a protective film having the specific physical properties described above. preferable. However, especially from the viewpoint of satisfying the condition of formula (1), the material constituting the protective film in the protective film can be a material different from the resin (a1) usually constituting the base material. Examples of such materials include a resin capable of exhibiting a lower storage elastic modulus than the one employed as a component of the base material among the examples of the resin (a1) described above, and a polymer containing an alicyclic structure having crystallinity. Resins, including crystalline polymers other than coalescence, and other materials are included.

Examples of the crystalline polymer that constitutes the resin (b1) include, among the examples of the polymer that constitutes the resin (a1) described above, a polymer different from that employed as a component of the base material. mentioned.

Further examples of the crystalline polymer constituting the resin (b1) include styrenic polymers (e.g., homopolymers of styrene or styrene derivatives or copolymers thereof with other polymerizable monomers); Cellulosic polymers such as triacyl cellulose; Polyolefins such as polyethylene and polypropylene; Polyesters such as polyethylene terephthalate, polybutylene terephthalate and polyethylene naphthalate; Polyarylene sulfides such as polyphenylene sulfide; Polyvinyl alcohol; polysulfone; polyarylsulfone; polyvinyl chloride; acrylic polymers such as polymethyl methacrylate and polyacrylonitrile; polyimide; These polymers may be homopolymers or copolymers.

In particular, examples of polystyrene-based polymers having crystallinity include those described in JP-A-2011-118137.

The resin (b1) may contain optional components in addition to the polymer. Examples of optional components that can be contained in the resin (b1) include the same components as examples of optional components that can be contained in the resin (a1). The resin (b1) may contain a polymer singly or in combination of two or more at any ratio. The proportion of the polymer in 100% by weight of the resin (b1) is preferably 70% by weight or more, more preferably 80% by weight or more, and still more preferably 85% by weight or more, and is usually 100% by weight or less. may be

The glass transition temperature of the resin (b1) is preferably 60°C or higher, more preferably 70°C or higher, and preferably 180°C or lower, more preferably 170°C or lower. When the glass transition temperature of the resin (b1) is at least the lower limit, the heat resistance of the laminate can be effectively improved. In addition, when the glass transition temperature is equal to or lower than the upper limit, moldability can be improved.

When the protective film is combined with the adhesive layer to form a composite film, the surface of the protective film on the side in contact with the adhesive layer may be subjected to surface treatment such as corona treatment or plasma treatment. That is, one surface of the protective film can be surface-treated and an adhesive layer can be formed on the surface. By performing such a surface treatment, the adhesion between the protective film and the adhesive layer is enhanced, and as a result, when the substrate is peeled off from the protective film at the time of use, good peeling without adhesive residue can be easily achieved. be able to.

The thickness of the protective film in the laminate is preferably 5 μm or more, more preferably 10 μm or more, and preferably 150 μm or less, more preferably 140 μm or less.

When the protective film in the laminate of the present invention is a layer of a resin containing a crystalline polymer, the polymer constituting the protective film may be crystallized with a degree of crystallinity above a certain level. A specific crystallinity range is preferably 20% or higher, more preferably 25% or higher, and particularly preferably 30% or higher. Although the upper limit of the crystallinity is not particularly limited, it can be 95% or less.

[Adhesive layer]
When the laminate of the present invention is provided with an adhesive layer, examples of adhesives constituting the adhesive layer include those using various polymers as base polymers. Examples of such base polymers include acrylic polymers, urethane polymers, polyester polymers, rubber polymers, epoxy polymers, and silicone polymers. In addition, the adhesive may contain optional components such as a polymerization initiator, a curing agent, an ultraviolet absorber, a colorant, and an antistatic agent in combination with the base polymer.
Adhesives include adhesives (pressure sensitive adhesives).

A commercially available product can be used as the adhesive. In addition, since various adhesive layers are commercially available as films having adhesiveness, the adhesive layer can be constructed by using them. The adhesive layer may have a single layer structure or a multilayer structure.

The thickness of the adhesive layer is not particularly limited, and can be in the range of, for example, 3 μm to 30 μm, such as 5 μm to 20 μm.

[Method for manufacturing laminate]
The laminate of the invention can be produced by any method. From the viewpoint of easily producing a laminate that satisfies the requirements defined by formulas (1) and (2), the laminate of the present invention can be produced by a production method including the following steps (1) and (2). preferable. The manufacturing method will be described below as a method for manufacturing the laminate of the present invention.
Step (1): A step of laminating the pre-annealed base material and the pre-annealed protective film to obtain a pre-annealed laminate comprising the pre-annealed base material and the pre-annealed protective film.
Step (2): A step of annealing the pre-annealed laminate.

[Base material before annealing]
Examples of the material of the pre-annealing base material used in step (1) are the same as those listed above as examples of the resin (a1), which is the material constituting the base material of the laminate of the present invention. However, since the pre-annealed substrate and pre-annealed protective film may have different storage modulus and thermal shrinkage than the substrate and protective film in the laminate, they are at this point represented by formulas (1)-(2) above. does not have to be satisfied.

The method for preparing the base material before annealing is not particularly limited, and it can be prepared by any film manufacturing method. Specifically, the substrate before annealing can be prepared by employing a known molding method such as a melt extrusion method and molding the resin (a1) into a long film shape. Alternatively, a commercially available product may be used as the base material before annealing.

A film obtained by molding the resin (a1) by a molding method such as a melt extrusion method, or a commercially available film of the resin (a1) can be used as it is as a base material before annealing. Alternatively, these films may be used as raw films, optionally subjected to any treatment, and then used as the base material before annealing. For example, a raw film may be subjected to a process of stretching to obtain a film having desired retardation, dimensions and other properties, which may be used as a pre-annealing substrate. Furthermore, in order to obtain desired properties, the stretching may be followed by a step of promoting crystallization of the resin (a1).

There are no restrictions on the stretching direction, and examples include the longitudinal direction, width direction, and oblique direction. Here, the oblique direction means a direction perpendicular to the thickness direction and neither parallel nor perpendicular to the width direction. Moreover, the stretching direction may be one direction or two or more directions. Therefore, as the stretching method, for example, a method of uniaxially stretching the original film in the longitudinal direction (longitudinal uniaxial stretching method), a method of uniaxially stretching the original film in the width direction (horizontal uniaxial stretching method), etc. Uniaxial stretching method. A simultaneous biaxial stretching method in which the original film is stretched in the longitudinal direction and in the width direction at the same time, a sequential biaxial stretching method in which the original film is stretched in one of the longitudinal direction and the width direction and then stretched in the other direction, etc. Biaxial stretching method; method of stretching the raw film in an oblique direction (diagonal stretching method); and combinations thereof.

Examples of modes of uniaxial stretching include fixed-end uniaxial stretching and free-end uniaxial stretching. The fixed-end uniaxial stretching method is a stretching method in which the ends in the direction perpendicular to the stretching direction of the raw film are fixed, and the free-end uniaxial stretching method fixes the ends in the direction perpendicular to the stretching direction of the raw film. It is a drawing method performed without stretching. The longitudinal uniaxial stretching method is often free-end uniaxial stretching, and the transverse uniaxial stretching method is often fixed-end uniaxial stretching.

The draw ratio can be adjusted as appropriate so that the substrate in the laminate has desired retardation, dimensions and other properties. Specifically, it is preferably 1-fold or more, more preferably 1.01-fold or more, preferably 15-fold or less, more preferably 11-fold or less. When the stretching is biaxial stretching, it is preferable that the area ratio, that is, the product of the stretching ratios in two directions is within such a range.

The stretching temperature is preferably "Tg + 5°C" or higher, more preferably "Tg + 10°C" or higher, preferably "Tg + 100°C" or lower, more preferably "Tg + 90°C" or lower. Here, "Tg" represents the glass transition temperature of the polymer being stretched. When the stretching temperature is equal to or higher than the lower limit of the above range, the original film can be sufficiently softened and stretched uniformly. In addition, when the stretching temperature is equal to or lower than the upper limit of the above range, it is possible to suppress the hardening of the original film due to the progress of crystallization of the polymer, so that the stretching can be performed smoothly, and the stretching causes a large birefringence. can be expressed. In addition, usually the haze of the resulting substrate can be reduced to increase transparency.

The crystallization promotion step can be performed by heating the film after the stretching step. Such heating can be done while the film dimensions are controlled and maintained at the stretched dimensions, or by shrinking the stretched dimensions by a controlled fraction. The ratio of dimensional change when the film is shrunk is preferably 0.90 times or more and less than 1 time. When the film is shrunk in two directions, the product of the area magnification, that is, the magnification of the dimensional change in the two directions is preferably within such a range. The reduction ratio is the ratio of the size after reduction to the size before reduction being 1.

The heating temperature in the crystallization promoting step is usually higher than the glass transition temperature Tg of the crystalline polymer and lower than the melting point Tm of the crystalline polymer. More specifically, the heating temperature is preferably Tg° C. or higher, more preferably Tg+10° C. or higher, and preferably Tm−10° C. or lower, more preferably Tm−20° C. or lower. By setting the heating temperature within this range, crystallization of the crystalline polymer can be rapidly progressed while suppressing white turbidity due to progress of crystallization.

The heat treatment time is preferably 1 second or longer, more preferably 5 seconds or longer, and preferably 30 minutes or shorter, more preferably 15 minutes or shorter.

[Pre-annealing protective film and adhesive layer]
Examples of the material of the pre-annealing protective film used in step (1) are the same as those listed above as examples of the resin (b1), which is the material constituting the protective film of the laminate of the present invention.

The method for preparing the protective film before annealing is not particularly limited, and it can be prepared by any film manufacturing method. Specifically, a pre-annealing protective film can be prepared by employing a known molding method such as a melt extrusion method and molding the resin (b1) into a long film shape. Alternatively, a commercially available product may be used as the pre-annealing protective film. The pre-annealing protective film may be a stretched film, but may also be a film that has not been stretched.

Prior to step (1), an adhesive layer may be provided on the surface of the protective film before annealing to form a composite film. The adhesive layer can be formed by applying an adhesive to the surface of the pre-annealing protective film. The applied adhesive layer can be further subjected to a curing treatment as necessary to obtain an adhesive layer having desired physical properties. Alternatively, the adhesive layer can be provided by transferring a layer of an adhesive film to the surface of the protective film before annealing.

Examples of coating methods for coating the adhesive include wire bar coating, spray coating, roll coating, gravure coating, die coating, curtain coating, slide coating, and extrusion coating. be done. Examples of adhesive curing treatments include drying treatments, examples of which include vacuum drying, heat drying, and combinations thereof.

[Physical properties of base material before annealing and protective film before annealing]
Since the pre-annealing base material is a resin layer containing a crystalline alicyclic structure-containing polymer, the polymer constituting the pre-annealing base material can be crystallized with a degree of crystallinity above a certain level. . A specific crystallinity range is preferably 20% or higher, more preferably 25% or higher, and particularly preferably 30% or higher. Although the upper limit of the crystallinity is not particularly limited, it can be 95% or less.

When the pre-annealing protective film is a layer of a resin containing a crystalline polymer, the polymer constituting the pre-annealing protective film can be crystallized with a degree of crystallinity above a certain level. A specific crystallinity range is preferably 20% or higher, more preferably 25% or higher, and particularly preferably 30% or higher. Although the upper limit of the crystallinity is not particularly limited, it can be 95% or less.

The storage elastic modulus and thermal shrinkage of the pre-annealed base material and pre-annealed protective film are such that the storage elastic modulus and thermal shrinkage of the base material and protective film in the product laminate are the desired values described above. and preparation conditions can be adjusted accordingly. The storage elastic modulus and thermal shrinkage of the pre-annealed base material and the pre-annealed protective film and their ratios themselves are not particularly limited, but values within the following ranges are preferred.

The storage elastic modulus pE's at 180°C of the base material before annealing and the storage elastic modulus pE'p at 180°C of the protective film before annealing are in a specific range of their ratio pE's/pE'p. is preferred. The value of pE's/pE'p is preferably less than 1, more preferably 0.95 or less, even more preferably 0.90 or less. Although the lower limit of pE's/pE'p is not particularly limited, it can be 0.1 or more. Each value of pE's and pE'p is not particularly limited, but can be, for example, 1.0×10 ⁷ Pa or more and 1.0×10 ⁹ Pa or less.

In addition, the thermal shrinkage rate pFs (%) of the base material before annealing in the longitudinal direction of the laminate at 180 ° C. 2 minutes and the thermal shrinkage rate pFp (%) of the protective film in the longitudinal direction of the laminate at 180 ° C. 2 minutes before annealing are The difference pFs-pFp is preferably a value within a specific range. The value of pFs−pFp is preferably −1.0% or more, more preferably −0.8% or more, while preferably 1.0% or less, more preferably 0.8% or less. be. Each value of pFs and pFp is not particularly limited, but can be, for example, -0.3% or more and 1.0% or less.

When the value of pE's/pE'p and the value of pFs-pFp are within the above preferred ranges, the laminate of the present invention comprising a substrate and a protective film that satisfy the above formulas (1) and (2) can be easily manufactured. can be manufactured to

[Step (1)]
Step (1) can be carried out by stacking a long pre-annealed base material and a pre-annealed protective film on top of each other with their longitudinal directions aligned, and pressurizing them. Pressurization can be performed continuously by a device such as a nip roll that presses a long film. When the protective film before annealing constitutes a composite film with an adhesive layer, the surface of the composite film on the side of the adhesive layer is laminated to the surface of the substrate before annealing, thereby providing the substrate before annealing and the protection before annealing. A pre-annealed laminate in which the film is bonded via an adhesive layer can be obtained.

[Step (2)]
The annealing treatment in step (2) can be performed by heating the pre-annealed laminate while restraining it in at least one of its in-plane directions. The pre-annealed laminate can be constrained, for example, by constraining the pre-annealed laminate in its longitudinal direction, width direction, or both directions.

Annealing treatment involving restraint in the longitudinal direction of the pre-annealed laminate can be performed using, for example, a roll support type film dryer. The roll support type dryer is equipped with an upstream nip roll, a downstream nip roll, and an oven provided between them, and by adjusting the peripheral speed ratio between the upstream nip roll and the downstream nip roll, A long film is transported under tension, passed through the oven in between, and guided by only unconstrained rolls that support the film from below in the oven. It is an apparatus capable of heating the film without restraint in the width direction of the film. Annealing treatment can be performed by conveying the pre-annealed laminate in a direction along its longitudinal direction, continuously introducing it into a dryer, and heating it. In this case, the tension applied to the film is preferably 3 N/m or more and 25 N/m or less.

Annealing treatment involving restraint in the longitudinal direction of the pre-annealed laminate can be performed, for example, using an apparatus having the same structure as the apparatus used for stretching. More specifically, a device such as a tenter-type stretching machine that can control both the longitudinal and width dimensions of a long film and continuously heat the film is used, and the film is stretched in the stretching machine. Annealing can be performed by conveying and heating the film while it is gripped and the dimensions in the longitudinal and width directions of the film are maintained unchanged.

The heating temperature in the annealing treatment is usually higher than the glass transition temperature Tg of the crystalline polymer and lower than the melting point Tm of the crystalline polymer. More specifically, the heating temperature is preferably Tg+20° C. or higher, more preferably Tg+40° C. or higher, and preferably Tm−20° C. or lower, more preferably Tm−40° C. or lower. The heating time is preferably 5 seconds or longer, more preferably 10 seconds or longer, while preferably 30 minutes or shorter, more preferably 15 minutes or shorter. By setting the heating temperature and time within the ranges that require good annealing treatment, it is possible to obtain the laminate of the present invention comprising the base material and the protective film after annealing.

When the pre-annealed base material, which is a resin film containing a crystalline alicyclic structure-containing polymer, is annealed alone without a protective film, the flatness is likely to be impaired, and such a phenomenon is , especially when the pre-annealed substrate is stretched at a high areal ratio prior to annealing. As a measure for reducing such deterioration of flatness, it is conceivable to laminate the base material with a protective film prior to annealing treatment. However, simply providing the protective film does not reduce the damage to the flatness, and the resulting substrate may not exhibit sufficient heat resistance due to the annealing treatment.

Here, according to the present inventors, the materials of the pre-annealed base material and the pre-annealed protective film and the treatment conditions prior to the annealing treatment are changed to the above formulas (1) and ( A laminated body having good flatness and heat resistance can be easily produced by preparing a laminated body before annealing in a state appropriately adjusted so as to satisfy 2) and subjecting this to an annealing treatment.

[Optional step]
The method for producing a laminate of the present invention may further include optional steps in addition to the steps (1) and (2). Examples of such optional steps include a step of forming an additional layer such as a conductive layer on the surface of the substrate included in the laminate, and a step of winding the laminate to obtain a roll.

[Application of laminate]
The laminate of the present invention can be used as it is as a constituent element of an optical device, or a constituent element of other electronic and electrical parts that are not limited to optical devices. Alternatively, the protective film can be peeled off from the laminate of the present invention, and the remaining substrate can be used as a component of optical devices or other electronic and electrical components.
Examples of components of optical devices include substrate films, retardation films, polarizing films, and light diffusion sheets in display devices such as liquid crystal display devices and organic electroluminescence display devices and other devices. The substrate film can be used particularly effectively as a touch panel substrate film and a flexible display substrate film by taking advantage of its flexibility. In addition, it is preferably used as a constituent element of light-condensing sheets, optical cards, and the like.
Examples of other electronic components and components of electrical components include films for flexible printed circuit boards, film capacitors, high frequency circuit board films, antenna substrate films, battery separator films, and release films.
The laminate can maintain good flatness, undergo little change in shape due to heat load, and curl less in a high-temperature environment. Therefore, it can be used particularly useful as a base material for manufacturing an optical element (for example, a conductive layer included in a touch panel) whose formation process is performed at high temperature. By providing a desired retardation, the substrate in the laminate of the present invention can also be used particularly effectively as a retardation layer after peeling from the laminate. The substrate in the laminate of the present invention can further be used as a protective film for protecting a polarizer, taking advantage of its high flatness and heat resistance.

The present invention will be specifically described below with reference to examples. However, the present invention is not limited to the examples shown below, and can be arbitrarily modified without departing from the scope of the claims of the present invention and their equivalents.

In the following explanation, "%" and "parts" representing amounts are based on weight unless otherwise specified. In addition, unless otherwise specified, the operations described below were performed under normal temperature and pressure conditions.

〔Evaluation method〕
(Polymer weight average molecular weight Mw and number average molecular weight Mn)
The weight average molecular weight Mw and number average molecular weight Mn of the polymer were measured as polystyrene equivalent values using a gel permeation chromatography (GPC) system ("HLC-8320" manufactured by Tosoh Corporation). During the measurement, an H-type column (manufactured by Tosoh Corporation) was used as the column, and tetrahydrofuran was used as the solvent. The column temperature during measurement was 40°C.

(Method for measuring hydrogenation rate of polymer)
The hydrogenation rate of the polymer was measured by ¹ H-NMR measurement at 145° C. using ortho-dichlorobenzene-d ₄ as a solvent.

(Glass transition temperature Tg and melting point Tm)
The polymer was melted by heating and the melted polymer was quenched with dry ice. Subsequently, using this polymer as a test sample, a differential scanning calorimeter (DSC) was used to measure the glass transition temperature Tg and melting point Tm of the polymer at a heating rate of 10° C./min (heating mode). It was measured.

(Proportion of racemo diad in hydrogenated ring-opening polymer)
Using ortho-dichlorobenzene-d ₄ /1,2,4-trichlorobenzene (TCB)-d ₃ (mixing ratio (mass basis) 1/2) as a solvent, ¹³ C was applied at 200 ° C. by inverse-gated decoupling method. - NMR measurement was performed to determine the ratio of racemo dyads. Specifically, a 43.35 ppm signal from the meso dyad and a 43.43 ppm signal from the _racemo dyad were identified using the ortho-dichlorobenzene-d4 peak at 127.5 ppm as the reference shift. Based on the intensity ratio of these signals, the ratio of racemo dyads was determined.

(film thickness)
The thickness of the film was measured using a contact thickness gauge (Code No. 543-390, manufactured by MITUTOYO).

(Thermal shrinkage rate)
In the measurement of the thermal shrinkage rate (pFs and pFp) of the pre-annealed base material and the pre-annealed protective film, each film was cut out in an environment of 23 ° C. (room temperature) to obtain a square sample film with a size of 120 mm × 120 mm. . On the other hand, in the measurement of the thermal shrinkage rate (Fs and Fp) of the base material and the protective film, which are each layer of the laminate after annealing, the laminate was cut out in an environment of 23 ° C. (room temperature) and a size of 120 mm × 120 mm. A square section was taken, and the base material and the composite film were peeled off to obtain a sample film. Since the effect of the adhesive layer on the thermal shrinkage rate is negligible, the thermal shrinkage rate of the protective film was measured in the state of the composite film with the adhesive layer. Each side of the square of the sample film was oriented parallel to the longitudinal direction or width direction of the film.

This sample film was heated under predetermined heating conditions, then cooled to 23°C (room temperature), and then the lengths of the four sides of the sample film were measured. Two heating conditions, 145° C. for 60 minutes and 200° C. for 10 minutes, were used for the measurement of the base material before annealing and the protective film before annealing. In the measurement of the substrate and protective film after annealing, the heating conditions were 180° C. for 2 minutes. Further measurements on the substrate after annealing were performed at 145° C. for 60 minutes and 200° C. for 10 minutes.

Based on the measured length of each of the four sides, the thermal shrinkage rate of the sample film was calculated based on the following formula (I). In formula (I), LB indicates the _side length of the sample film before heating, LB is 120 mm in this measurement, and _LA indicates the _side length of the sample film after heating.
Thermal shrinkage rate (%) = [(L _B -L _A )/L _B ]×100 (I)
A positive value for the thermal shrinkage ratio indicates that the film shrinks due to heating, and a negative value indicates that the film elongates due to heating.

The average value of the shrinkage rate of the two sides along the transport direction of the film (that is, the longitudinal direction of the long film) is taken as the heat shrinkage rate in the transport direction of the film, that is, the heat shrinkage rate in the longitudinal direction of the long film. adopted. Also, the average value of the heat shrinkage rates of the two sides along the width direction of the film was adopted as the heat shrinkage rate in the width direction of the long film. Furthermore, for the base material and protective film after annealing, the value of Fs - Fp was obtained from the heat shrinkage rate Fs (%) in the longitudinal direction of the base material and the heat shrinkage rate Fp (%) in the longitudinal direction of the protective film. .

(elastic modulus)
In an environment of 23 ° C. (room temperature), cut the laminate after annealing into rectangular pieces with a size of 20 mm in length × 5 mm in width, peel off the base material and the composite film, and use each as a sample film. did. Since the effect of the adhesive layer on the elastic modulus is negligibly small, the elastic modulus of the protective film was measured in the form of a composite film with the adhesive layer. The sides of the rectangle of the sample film in the longitudinal direction were parallel to the longitudinal direction of the long laminate.
Using a dynamic viscoelasticity measuring device (manufactured by Hitachi High-Tech Science, product name: DMA7100), perform stretching viscoelasticity measurement at a frequency of 1 Hz, a temperature increase rate of 5 ° C. per minute, and a temperature range of 25 to 220 ° C. Storage at 180 ° C. The elastic moduli E's and E'p were taken.

(flat smoothness)
The annealed laminate was cut into a square piece of 300 mm×300 mm, and the substrate and the protective film were peeled off. The base material was spread on a horizontal and flat desk, and the smoothness of the surface of the base material was visually evaluated according to the following criteria.
Good: No corrugated sheet-like wrinkles with streaks along the conveying direction, practically no problem.
Acceptable: Slight corrugated sheet-like wrinkles having streaks along the conveying direction, but no problem in practical use.
Poor: There are corrugated sheet-like wrinkles with streaks along the conveying direction, which poses a practical problem.

(Curl amount of laminate after annealing)
In an environment of 23° C. (room temperature), the laminate after annealing was cut out to obtain a square sample film of 50 mm×50 mm. The sample film was placed on the top of a horizontal, flat desk. When placing, the sample film was observed, and the surface on the side that seemed to have shrunk and formed a concave shape was set as the upper side. The amount (curl amount) of the four corners of the sample film lifted from the top surface of the desk was measured with a ruler, and the average value of the four corners was taken as the curl amount of the sample film.

(crystallinity)
The crystallinity of the base material before annealing and the protective film before annealing was measured by the following method, using these as sample films cut into appropriate sizes.
The degree of crystallinity of the substrate and the protective film, which are each layer of the laminate after annealing, is measured by cutting the laminate into an appropriate size, peeling off the substrate and the protective film, and removing the adhesive layer attached to the protective film with methyl ethyl ketone. It was wiped off with an organic solvent such as , and a sample film which was sufficiently dried was measured by the following method.

(Crystallinity of base film/PET film)
The density of the sample film was measured using a helium gas replacement type dry automatic density meter "AccuPyc 1340" (manufactured by Micromeritics). About 3 g of the sample film was cut into strips having a width of 30 mm or less, rolled into a container of 10 cm ³ , and measured while maintaining the temperature at 25°C. Density was determined from 10 replicate measurements.

Crystallinity x (%) was calculated by the following formula.
x=(1/Da−1/D)/(1/Da−1/Dc)×100
In the above formula, x represents the degree of crystallinity. D (g/cm ³ ) represents the determined density of the sample film. Da indicates the complete amorphous density (g/cm ³ ) of the polymer forming the sample film. Db indicates the full crystal density (g/cm ³ ) of the polymer forming the sample film.

The following values were used as the complete amorphous density Da.
- Full amorphous density Da of the hydrogenated dicyclopentadiene ring-opening polymer produced in Production Example 1 = 1.0157 g/cm ³
・ Completely amorphous density of polyethylene terephthalate (PET) Da = 1.335 g / cm ³

The following values were used as the complete crystal density Dc.
- Complete crystal density Dc of the hydrogenated dicyclopentadiene ring-opening polymer produced in Production Example 1 = 1.0857 g/cm ³
・Perfect crystal density of PET Dc = 1.455 g/cm ³

(Crystallinity of SPS film)
Using a differential scanning calorimeter (DSC), the enthalpy of crystallization and the enthalpy of melting were measured when the sample film was heated from 50° C. to 300° C. at a heating rate of 20° C./min, and calculated according to the following equations.
Crystallinity (%) = {[melting enthalpy (J/g) - crystallization enthalpy (J/g)]/melting enthalpy at 100% crystallinity (J/g)} x 100
Here, 53 J/g was used as the melting enthalpy (J/g) when the degree of crystallinity was 100%.

(Crystallinity of polyamide film)
The crystallinity of the sample film, which is a polyamide film, was measured by the X-ray diffraction method.

[Production Example 1: Crystalline resin]
After sufficiently drying the metal pressure-resistant reactor, the atmosphere was replaced with nitrogen. In this metal pressure-resistant reactor, 154.5 parts of cyclohexane, 42.8 parts of a 70% cyclohexane solution of dicyclopentadiene (the content of endo bodies is 99% or more) (30 parts as the amount of dicyclopentadiene), and 1- Add 1.9 parts of hexene and heat to 53°C.

A solution was prepared by dissolving 0.014 parts of a tetrachlorotungstenphenylimide (tetrahydrofuran) complex in 0.70 parts of toluene. To this solution, 0.061 part of a 19% diethylaluminum ethoxide/n-hexane solution was added and stirred for 10 minutes to prepare a catalyst solution. This catalyst solution was placed in a pressure-resistant reactor to initiate ring-opening polymerization reaction. Thereafter, the mixture was allowed to react for 4 hours while maintaining the temperature at 53° C. to obtain a solution of a ring-opening polymer of dicyclopentadiene. The obtained ring-opening polymer of dicyclopentadiene had a number average molecular weight (Mn) and a weight average molecular weight (Mw) of 8,750 and 28,100, respectively. was 3.21.

0.037 parts of 1,2-ethanediol was added as a terminator to 200 parts of the obtained solution of the ring-opening polymer of dicyclopentadiene, heated to 60° C., and stirred for 1 hour to terminate the polymerization reaction. let me 1 part of a hydrotalcite-like compound (“Kyoward (registered trademark) 2000” manufactured by Kyowa Chemical Industry Co., Ltd.) was added thereto, heated to 60° C., and stirred for 1 hour. After that, 0.4 part of a filter aid ("Radiolite (registered trademark) #1500" manufactured by Showa Kagaku Kogyo Co., Ltd.) is added, and a PP pleated cartridge filter ("TCP-HX" manufactured by ADVANTEC Toyo Co., Ltd.) is used as an adsorbent. The solution was filtered off.　

To 200 parts of the solution of the ring-opening polymer of dicyclopentadiene after filtration (polymer amount: 30 parts), 100 parts of cyclohexane was added, 0.0043 parts of chlorohydridocarbonyltris(triphenylphosphine)ruthenium was added, and hydrogen was added. A hydrogenation reaction was carried out at a pressure of 6 MPa and 180° C. for 4 hours. As a result, a reaction liquid containing a hydride of a ring-opening polymer of dicyclopentadiene was obtained. This reaction solution was a slurry solution due to deposition of hydride.

The hydride contained in the reaction solution and the solution were separated using a centrifugal separator and dried under reduced pressure at 60° C. for 24 hours to obtain a crystalline hydride of a ring-opening polymer of dicyclopentadiene 28. 5 copies were obtained. This hydride had a hydrogenation rate of 99% or more, a glass transition temperature Tg of 93° C., a melting point (Tm) of 267° C., and a ratio of racemo diad of 89%.

An antioxidant (tetrakis[methylene-3-(3′,5′-di-t-butyl-4′-hydroxyphenyl)propionate]methane) was added to 100 parts of the hydride of the resulting ring-opening polymer of dicyclopentadiene. ; After mixing 1.1 parts of "Irganox (registered trademark) 1010" manufactured by BASF Japan Co., Ltd., a twin-screw extruder equipped with four die holes with an inner diameter of 3 mmΦ (product name "TEM-37B", manufactured by Toshiba Machine Co., Ltd. ). A mixture of a hydride of a ring-opening polymer of dicyclopentadiene and an antioxidant is formed into strands by hot-melt extrusion molding, and then chopped with a strand cutter to form a pellet-shaped crystalline resin (resin A). got The operating conditions of the twin-screw extruder were as follows.

・Barrel setting temperature = 270-280℃
・Die setting temperature = 250°C
・Screw rotation speed = 145 rpm

[Example 1]
(1-1. Base material before annealing)
100 parts of resin A produced in Production Example 1 was mixed with 0.05 parts of an anti-blocking agent (silica particles, manufactured by Admatechs, product name: "ADMAFINE SILICA SC4053-SQ"), and then heated with a T die. Molding was performed using a melt extrusion film molding machine to obtain a long extruded film (thickness: 500 μm) with a width of approximately 1200 mm. The operating conditions of the film forming machine were as follows.
・Barrel setting temperature = 280°C to 300°C
・Die temperature = 270°C
・Cast roll temperature = 80°C

The extruded film was supplied to a simultaneous biaxial stretching machine and subjected to a simultaneous biaxial stretching process. The stretching ratio was 3.5 times in the longitudinal direction and 2.9 times in the width direction, and the stretching temperature was 115°C. After the stretching step, the film was subjected to a crystallization promotion step. To promote crystallization, the film is held in a stretching machine and heated to a temperature of 240°C for 15 seconds to reduce the film dimensions to 0.94 times in the longitudinal direction and 0.96 times in the width direction. It was done by After completion of the crystallization promoting step, the film was cooled to a temperature of 100° C. or lower, and both ends in the width direction of the film were cut by slitting to obtain a pre-annealed base material as a long film having a width of 1100 mm. The heat shrinkage rate, film thickness, and crystallinity of the obtained base material before annealing were measured.

(1-2. Composite film containing protective film before annealing)
A commercially available SPS (syndiotactic polystyrene) film having a thickness of 35 μm (manufactured by Kurashiki Boseki Co., Ltd., product name “Oidys (registered trademark) HNL”) was pulled out from a film roll, and one side was subjected to discharge treatment (corona treatment). A corona treatment apparatus (manufactured by Kasuga Denki Co., Ltd.) was used for the discharge treatment, and the discharge conditions were an output of 500 W, an electrode length of 1.35 m, and a conveying speed of 10 m/min.

On the surface of the film subjected to the discharge treatment, an acrylic pressure-sensitive adhesive (Fujimori Kogyo "Mastak series") as an adhesive was applied using a die coater so that the dry film thickness was 10 μm, The adhesive was dried by passing through a drying oven at 100°C. As a result, a composite film having a protective film, which is an SPS film, and an adhesive layer formed on one surface thereof was obtained as a long film with a width of 1100 mm. The heat shrinkage rate and crystallinity of the pre-annealed protective film were measured.

(1-3. Laminate before annealing)
One surface of the pre-annealed base material obtained in (1-1) and the adhesive layer side surface of the composite film obtained in (1-2) are aligned in the longitudinal direction and laminated with nip rolls, before annealing. A long pre-annealed laminate comprising a substrate and a pre-annealed protective film was produced.

(1-4. Laminate)
The pre-annealed laminate obtained in (1-3) was conveyed in the direction along its longitudinal direction, continuously introduced into a dryer, and subjected to annealing by heating. As a dryer, a roll support type dryer was used. This dryer includes an upstream nip roll, a downstream nip roll, and an oven provided between them. By adjusting the peripheral speed ratio between the upstream nip roll and the downstream nip roll, tension is applied to the film between the nip rolls. In the oven, the film is conveyed in a state in which the film It is a device that can heat a film without restraint in the width direction. The heating temperature in the annealing treatment was 200° C., the heating time was 2 minutes, and the transfer tension was 13N. As a result of such annealing treatment, a laminate including the substrate and the protective film was obtained.

(1-5. Evaluation)
The laminate obtained in (1-4) was evaluated for the elastic modulus of each layer, the thermal shrinkage of each layer, the crystallinity of each layer, the smoothness of the surface, and the amount of curl.

[Example 2]
A laminate was obtained and evaluated in the same manner as in Example 1 except for the following changes.
- In the preparation of the composite film containing the protective film before annealing in (1-2), instead of the 35 μm thick SPS film, a 75 μm thick SPS film (manufactured by Kurashiki Boseki Co., Ltd., product name “Oidys (registered trademark) CN”) was used.

[Example 3]
A laminate was obtained and evaluated in the same manner as in Example 1 except for the following changes.
- In the preparation of the base material before annealing in (1-1), the dimensions of the T-die opening and the operating conditions of the molding machine were changed, and the thickness of the extruded film was changed to 430 µm. Further, the draw ratio was changed from 3.5 times to 2.6 times in the longitudinal direction and from 2.9 times to 3.3 times in the width direction. However, the reduction ratio in the crystallization promoting step is the same as in Example 1. The width direction dimension of the obtained pre-annealed base material is also 1100 mm, which is the same as in Example 1.

[Example 4]
A laminate was obtained and evaluated in the same manner as in Example 1 except for the following changes.
- In the preparation of the base material before annealing in (1-1), the size of the T-die opening and the operating conditions of the molding machine were changed, and the thickness of the extruded film was changed to 1000 µm.

[Example 5]
(5-1. Base material before annealing)
Resin A produced in Production Example 1 was molded using a hot-melt extrusion film molding machine equipped with a T-die to obtain a long extruded film (thickness: 48 μm) with a width of approximately 1,350 mm. The operating conditions of the film forming machine were as follows.
・Barrel setting temperature = 280°C to 300°C
・Die temperature = 270°C
・Cast roll temperature = 80°C

The extruded film was supplied to a transverse stretching machine using a tenter method and subjected to fixed-end uniaxial stretching. The draw ratio was 1.0 times in the longitudinal direction and 1.35 times in the width direction. The extruded film was preheated at a temperature of 120°C prior to stretching and then stretched at a stretching temperature of 140°C. After the stretching step, the film was subjected to a crystallization promotion step. Acceleration of crystallization was carried out by holding the film in a stretching machine, conveying the film in a state in which the film dimension was maintained without changing, and heating the film to a temperature of 160° C. for 30 seconds. After completion of the crystallization promoting step, the film was cooled to a temperature of 100° C. or lower, and both ends in the width direction of the film were cut by slitting to obtain a pre-annealed base material as a long film having a width of 1100 mm. The thermal shrinkage rate, film thickness and crystallinity of the obtained pre-annealed base material were measured.

(5-2. Composite film including protective film before annealing)
A commercially available PET film (manufactured by Toray Industries, Inc., product name “Lumirror S10”, thickness 125 μm) was pulled out from the film roll, and one side was subjected to discharge treatment (corona treatment). A corona treatment apparatus (manufactured by Kasuga Denki Co., Ltd.) was used for the discharge treatment, and the discharge conditions were an output of 500 W, an electrode length of 1.35 m, and a conveying speed of 10 m/min.

On the surface of the film subjected to the discharge treatment, an acrylic pressure-sensitive adhesive (Fujimori Kogyo "Mastak series") as an adhesive was applied using a die coater so that the dry film thickness was 10 μm, The adhesive was dried by passing through a drying oven at 100°C. As a result, a composite film having a protective film that is a PET film and an adhesive layer formed on one surface thereof was obtained as a long film with a width of 1100 mm. The thermal shrinkage rate and crystallinity of the obtained pre-annealed protective film were measured.

(5-3. Laminate before annealing)
One surface of the pre-annealed substrate obtained in (5-1) and the adhesive layer side surface of the composite film obtained in (5-2) are aligned in the longitudinal direction and laminated with nip rolls, and before annealing A long pre-annealed laminate comprising a substrate and a pre-annealed protective film was produced.

(5-4. Laminate)
The pre-annealed laminate obtained in (5-3) was conveyed in the direction along its longitudinal direction, continuously introduced into a dryer, and subjected to annealing by heating. A transverse stretching machine was used as the drying machine, and the film was held in the stretching machine, and the film was conveyed and heated while the dimensions in the longitudinal direction and the width direction of the film were kept unchanged. The heating temperature in the annealing treatment was 170° C., and the heating time was 5 minutes. As a result of such annealing treatment, a laminate including the substrate and the protective film was obtained.

(5-5. Evaluation)
The laminate obtained in (5-4) was evaluated for the elastic modulus of each layer, the thermal shrinkage of each layer, the crystallinity of each layer, the smoothness of the surface, and the amount of curl.

[Example 6]
A laminate was obtained and evaluated in the same manner as in Example 5 except for the following changes.
- In the preparation of the base material before annealing in (5-1), the dimensions of the T-die opening and the operating conditions of the molding machine were changed, and the thickness of the extruded film was changed to 42 µm. Furthermore, the draw ratio in the width direction was changed from 1.35 times to 1.2 times (longitudinal direction was unchanged at 1.0 times). However, the reduction ratio in the crystallization promoting step is the same as in Example 5. The width direction dimension of the obtained pre-annealed base material is also 1100 mm, which is the same as in Example 1.

[Comparative Example 1]
A laminate was obtained and evaluated in the same manner as in (1-1) and (1-3) to (1-5) of Example 1, except for the following changes.
· In (1-3), the composite film containing the protective film before annealing was used instead of the one obtained in (1-2) in Example 5 (5-2).

[Comparative Example 2]
A laminate was obtained by the same operation as in Example 1, except for the following changes.
・In the preparation of the composite film containing the protective film before annealing in (1-2), instead of the SPS film with a thickness of 35 μm, a commercially available alicyclic structure-containing polymer film (manufactured by Nippon Zeon Co., Ltd., trade name “ ZeonorFilm™ ZF16”, thickness 146 μm) was used.

An attempt was made to evaluate the obtained laminate, but the base material and the protective film could not be separated, so the evaluation could not be performed.

[Comparative Example 3]
(C3-1. Composite film containing pre-annealing protective film)
Pellets of polyamide (manufactured by Daicel-Eponic Co., Ltd., product name "Trogamid CX7323") are molded using a hot-melt extrusion film molding machine equipped with a T-die to obtain a long extruded film (thickness 118 μm) with a width of about 1100 mm. rice field. The operating conditions of the film forming machine were as follows.
・Barrel setting temperature = 260°C to 280°C
・Die temperature = 250°C
・Cast roll temperature = 110°C

The extruded film was heat-treated using a roll support type dryer. The heating temperature was 180° C., and the heating time was 5 minutes. Discharge treatment (corona treatment) was performed on one side of the heat-treated film. A corona treatment apparatus (manufactured by Kasuga Denki Co., Ltd.) was used for the discharge treatment, and the discharge conditions were an output of 500 W, an electrode length of 1.35 m, and a conveying speed of 10 m/min.

On the surface of the film subjected to the discharge treatment, an acrylic pressure-sensitive adhesive (Fujimori Kogyo "Mastak series") as an adhesive was applied using a die coater so that the dry film thickness was 10 μm, The adhesive was dried by passing through a drying oven at 100°C. As a result, a composite film having a protective film made of a polyamide film and an adhesive layer formed on one surface thereof was obtained as a long film with a width of 1100 mm. The thermal shrinkage rate and crystallinity of the obtained pre-annealed protective film were measured.

(C3-2. Laminate)
A laminate was obtained and evaluated in the same manner as in (1-1) and (1-3) to (1-5) of Example 1, except for the following changes.
· In (1-3), the composite film containing the protective film before annealing was used instead of the one obtained in (1-2), obtained in (C3-1).

[Comparative Example 4]
A laminate was obtained and evaluated in the same manner as in Example 1 except for the following changes.
- In the preparation of the composite film containing the pre-annealed protective film in (1-2), the same substrate as the pre-annealed substrate obtained in (1-1) was used in place of the SPS film having a thickness of 35 µm. That is, in (1-2), a long composite film comprising the pre-annealed substrate obtained in (1-1) and an adhesive layer formed on one surface thereof is prepared and used. (1-3) and subsequent steps were performed.

[Comparative Example 5]
Without using the composite film containing the pre-annealed protective film, the pre-annealed base material obtained in (1-1) of Example 1 was directly subjected to the steps after Example (1-4) and evaluated.

The results of Examples and Comparative Examples are shown in Tables 1 to 4.

As is clear from the above results, in the Examples of the present application, the occurrence of wrinkles in the laminate was suppressed, the flatness of the substrate peeled from the laminate was maintained, and the thermal shrinkage rate of the substrate at 200 ° C. 10 minutes and All indexes relating to heat resistance such as heat shrinkage at 145° C. for 60 minutes were better than those of the comparative examples. From this, it can be seen that, according to the laminate of the present invention, a substrate having high flatness and high heat resistance can be easily supplied at the time of use.

10: Laminate 110: Base material 120: Composite film 121 Protective film 122: Adhesive layer

Claims

A laminate having a long shape, comprising a substrate and a protective film provided on one surface of the substrate,
The substrate is a resin layer containing a crystalline alicyclic structure-containing polymer,
A laminate in which the substrate and the protective film satisfy the following formulas (1) to (2):
E's/E'p<1 (1)
-0.4≤Fs-Fp≤0.4 (2)
however,
E's is the storage modulus of the base material at 180°C,
E'p is the storage modulus of the protective film at 180°C,
Fs is the thermal shrinkage rate (%) of the base material in the longitudinal direction of the laminate at 180 ° C. for 2 minutes,
Fp is the heat shrinkage rate (%) of the protective film in the longitudinal direction of the laminate at 180° C. for 2 minutes.
The laminate according to claim 1, wherein the protective film is a resin layer containing a crystalline polymer.
The laminate according to claim 1 or 2, wherein the resin containing the crystalline alicyclic structure-containing polymer constituting the base material is a hydride of a ring-opening polymer of dicyclopentadiene.
A method for producing a laminate according to any one of claims 1 to 3,
A step of bonding a pre-annealed base material and a pre-annealed protective film to obtain a pre-annealed laminate comprising the pre-annealed base material and the pre-annealed protective film, wherein the pre-annealed base material is a crystalline fat. A production method comprising: a step of forming a resin layer containing a cyclic structure-containing polymer; and a step of annealing the pre-annealed laminate.
The manufacturing method according to claim 4, wherein the pre-annealing protective film is a resin layer containing a crystalline polymer.
The production method according to claim 4 or 5, wherein the resin containing the crystalline alicyclic structure-containing polymer that constitutes the pre-annealing base material is a hydride of a ring-opening polymer of dicyclopentadiene.
The manufacturing method according to any one of claims 4 to 6, wherein the annealing includes heating the pre-annealed laminate while restraining it in at least one of its in-plane directions.