JP7334476B2 - Laminate manufacturing method - Google Patents

Description

The present invention relates to a laminate manufacturing method.

2. Description of the Related Art Conventionally, a technique is known in which a coating liquid is applied to the surface of a base material and the applied coating liquid is dried to produce a laminate. According to such techniques, it is generally possible to form a coat layer containing the components contained in the coating liquid or reaction products of the components on the substrate. As the substrate, for example, a resin film may be used (Patent Documents 1 and 2).

WO2018/079627 Japanese Patent No. 6434186

The present inventor attempted to produce a laminate using a new base material that had not been used in the production of conventional laminates. However, it has been found that when a specific base material is used, a laminate having a smooth surface cannot be produced.

Specifically, when these base materials were used, it was possible to uniformly apply the coating liquid to the base material. However, in the process of drying the coating liquid, the layer of the coating liquid applied on the base material became mottled, and the obtained coating layer also became mottled, so it was difficult to obtain a laminate with a smooth surface. could not. As described above, it is conventionally known that although the coating liquid can be applied uniformly, the layer of the coating liquid becomes mottled by subsequent drying, making it impossible to obtain a laminate having a smooth surface. This is a new issue that has not been

An object of the present invention is to provide a manufacturing method capable of manufacturing a laminate having a smooth surface using a substrate film having the above-mentioned novel problems.

The inventors have made extensive studies to solve the above problems. As a result, the present inventors believe that the above-mentioned new base material causes some components contained in the base material to bleed out when the coating liquid is dried, and the component that causes this bleeding out is the coating liquid. It was found that this is a factor that makes the layer mottled.

In the industrial manufacturing process of laminates, drying is generally performed in a heated environment. In this heating environment, some of the components contained in the substrate may bleed out. When bleed-out occurs, the component migrates to the surface of the substrate and changes the properties of the surface. Then, part or the whole of the layer of the coating liquid that has been evenly applied to the surface is repelled by the surface and becomes patchy. Therefore, conventionally, it has been difficult to obtain a laminate having a smooth surface.

On the other hand, the present inventors have found that even after the surface properties change due to the above-mentioned bleed-out, by adopting a coating liquid that can be uniformly fixed on the surface, the layer of the coating liquid The inventors have found that it is possible to produce a laminate having a smooth surface by suppressing the formation of mottles, and completed the present invention.
That is, the present invention includes the following.

[1] A coating liquid having a surface tension of 42 mN/m or less is applied to the surface of a substrate formed of a resin containing a polymer having a glass transition temperature Tg to form a layer of the coating liquid. a first step to
and a second step of drying the layer of the coating liquid,
After subjecting the base material to heat treatment for 30 seconds at a temperature of Tg-4 ° C. to Tg-3 ° C., when TOF-SIMS analysis was performed on the base material, a depth of 2 nm from the surface and The ratios Ia _{(2 nm)} and Ia _{(15 nm) of oxygen-containing ions to all secondary ions detected at a depth of 15 nm} are expressed by the following formulas (1) and (2):
Ia _{(2 nm)} ≧3% (1)
Ia _{(2 nm)} >Ia _{(15 nm)} (2)
A method for manufacturing a laminate that satisfies
[2] The method for producing a laminate according to [1], wherein the coating liquid contains polyurethane.
[3] The method for producing a laminate according to [1] or [2], wherein the drying temperature in the second step is Tg-10°C or higher and Tg+10°C or lower.
[4] The method for producing a laminate according to any one of [1] to [3], wherein the polymer is a polymer containing an alicyclic structure and having crystallinity.
[5] Ia _{(15 nm)} is represented by the following formula (3):
Ia _{(15 nm)} ≤ 1% (3)
The method for producing a laminate according to any one of [1] to [4], which satisfies.
[6] When TOF-SIMS analysis is performed on the base material before the base material is subjected to the heat treatment, oxygen-containing ions for all secondary ions detected at a depth of 2 nm from the surface. The ratio Ib _{(2 nm)} and the Ia _{(2 nm)} are represented by the following formula (4):
Ia _{(2 nm)} >Ib _{(2 nm)} (4)
The method for producing a laminate according to any one of [1] to [5], which satisfies the above.

According to the present invention, it is possible to provide a manufacturing method capable of manufacturing a laminate having a smooth surface by using the base film having the above-described novel problem.

FIG. 1 is a schematic diagram illustrating the measurement of the surface tension of a coating liquid by the hanging drop method.

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, a "long" film refers to a film having a length of 5 times or more, preferably 10 times or more, with respect to the width, specifically a roll A film that is long enough to be rolled up into a shape and stored or transported. Although there is no particular upper limit on the length, it is usually 100,000 times or less the width.

[1. Overview of Laminate Manufacturing Method]
A method for producing a laminate according to one embodiment of the present invention includes a first step of applying a coating liquid to the surface of a substrate to form a layer of the coating liquid; and drying the layer of the coating liquid. a second step of causing A coating liquid usually contains a solvent that can be removed by drying and a solid content that is not removed by drying. Therefore, according to the drying described above, a coating layer containing the solid content of the coating liquid or its reaction product can be formed on the surface of the substrate. Therefore, according to the manufacturing method described above, a laminate including a substrate and a coat layer can be manufactured.

In the present embodiment, a substrate that satisfies specific conditions is used as the substrate. A specific range of coating liquids applicable to such substrates is employed. According to such a combination of the base material and the coating liquid, it is possible to prevent the layer of the coating liquid from becoming mottled during drying, so that a uniform coating layer can be formed on the surface of the base material, resulting in a smooth surface. A laminate having a surface can be produced.

[2. Base material]
The substrate is made of a resin containing a polymer having a glass transition temperature Tg. This substrate can have any shape having a surface on which the coating liquid can be applied. Specific examples of the shape of the substrate include a film shape and a sheet shape. Usually, a substrate film as a resin film formed of the above resin is used as the substrate. In the following description, the surface of the base material to which the coating liquid is applied is sometimes referred to as the "coating surface". The number of coating surfaces that the substrate has may be one, or two or more. For example, only one surface of the substrate film may be coated, or both surfaces may be coated.

The substrate has Ia _{(2 nm)} and Ia _{(15 nm)} satisfying formulas (1) and (2) below.
Ia _{(2 nm)} ≧3% (1)
Ia _{(2 nm)} >Ia _{(15 nm)} (2)

The above Ia _{(2 nm)} is the depth from the coated surface when TOF-SIMS analysis (time-of-flight secondary ion mass spectrometry) is performed on the substrate after subjecting the substrate to a specific heat treatment. It represents the ratio of oxygen-containing ions to all secondary ions detected at 2 nm.
In addition, the above Ia _{(15 nm)} is detected at a depth of 15 nm from the coated surface when TOF-SIMS analysis is performed on the substrate after the substrate is subjected to the specific heat treatment. It represents the ratio of oxygen-containing ions to all secondary ions.
In the following explanation, the ratio of secondary ions detected by TOF-SIMS analysis is based on the number unless otherwise specified.
In addition, the ratio of oxygen-containing ions such as Ia _{(2 nm)} , Ia _{(15 nm)} , Ib _{(2 nm)} described later, and Ib _{(15 nm)} described later is determined by two factors generated at the portion where the oxygen-containing ions are detected. The value is expressed with the amount of the entire next ion as 100%.
The specific heating test mentioned above represents a test in which the substrate is heated at a temperature of Tg-4°C to Tg-3°C for 30 seconds. Tg represents the glass transition temperature of the polymer contained in the resin forming the substrate. The glass transition temperature Tg of the polymer can be measured using a differential scanning calorimeter (DSC) at a heating rate of 10° C./min (heating mode).

In TOF-SIMS analysis, a high-speed ion beam (primary ions) is hit on the surface of a solid sample in a high vacuum, causing the constituents of the surface to be ejected by a sputtering phenomenon, generating positively or negatively charged ions (secondary ions). The secondary ions are ejected in one direction by an electric field, and the mass of the secondary ions can be calculated from the time until they are detected by the detector. Further, in TOF-SIMS analysis, it is possible to perform analysis while etching the surface of a solid sample. It can be performed.

Therefore, the ratio of oxygen-containing ions detected at a depth of 2 nm from the coated surface, such as Ia _{(2 nm)} and Ib _{(2 nm)} described later, is the portion very close to the coated surface of the substrate (specifically Specifically, it represents the ratio of compounds containing oxygen atoms among the components contained in the portion separated from the coating surface by 2 nm in the thickness direction. Therefore, the formula (1) indicates that the heat-treated substrate contains a compound containing an oxygen atom at a specific concentration or higher in a portion very close to the specific surface. The fact that a compound containing an oxygen atom is included in a portion very close to a specific plane usually indicates that a large amount of the compound containing the oxygen atom is present on the specific plane.

On the other hand, the ratio of oxygen-containing ions detected at a depth of 15 nm from the coating surface, such as Ia _{(15 nm)} and Ib _{(15 nm)} described later, is the portion ( Specifically, it represents the ratio of compounds containing oxygen atoms among the components contained in the portion separated by 15 nm in the thickness direction from the coated surface. Therefore, formula (2) indicates that the substrate after heat treatment does not contain a compound containing an oxygen atom in a portion slightly away from the specific surface, or oxygen atoms contained in a portion slightly away from the specific surface The amount of the compound containing is smaller than the amount of the compound containing oxygen atoms contained in the portion very close to the coating surface.

Therefore, in the base material that satisfies the above formulas (1) and (2), a peculiar state may occur in which the oxygen atom-containing compound is disproportionately contained in the vicinity of the specific surface after the heat treatment.

To explain formula (1) in more detail, Ia _{(2 nm)} is usually 3% or more, and may be 4% or more or 5% or more. The upper limit is preferably 20% or less, more preferably 18% or less, and particularly preferably 15% or less, from the viewpoint of effectively suppressing the coat layer from becoming mottled.

To explain formula (2) in more detail, Ia _{(2 nm)} - Ia _{(15 nm)} is generally greater than 0%, preferably greater than 1%, and particularly preferably greater than 2%. Although there is no upper limit, it is preferably 20% or less, more preferably 18% or less, and particularly preferably 15% or less from the viewpoint of effectively suppressing the coating layer from becoming mottled.

In the substrate, Ia _{(15 nm)} preferably satisfies the following formula (3).
Ia _{(15 nm)} ≤ 1% (3)
More specifically, Ia _{(15 nm)} is preferably 0% to 1%, more preferably 0% to 0.8%, particularly preferably 0% to 0.5%. Conventional substrates with such a small Ia _{(15 nm)} were often capable of producing laminates with smooth surfaces. However, even if the base material has a small Ia _{(15 nm)} , when the above formulas (1) and (2) are satisfied, the above-mentioned specific problem that it becomes difficult to produce a laminate with a smooth surface occurs. was From the viewpoint of effectively utilizing the advantage of the present embodiment that this specific problem can be solved, it is desirable that Ia _{(15 nm)} is within the above range that satisfies Equation (3).

Ib is the ratio of oxygen-containing ions to all secondary ions detected at a depth of 2 nm from the coated surface when the substrate is subjected to TOF-SIMS analysis before the substrate is subjected to the heat treatment. _{(2 nm)} . In this case, Ib _{(2 nm)} and Ia _{(2 nm)} preferably satisfy the following formula (4).
Ia _{(2 nm)} >Ib _{(2 nm)} (4)
More particularly, Ia _(2nm) -Ib _(2nm) is preferably greater than 0%, and may be greater than 1% or greater than 2%. Formula (4) expresses that the amount of the compound containing oxygen atoms contained in the portion very close to the coating surface of the base material increases due to the heat treatment. Such an increase in the amount can be caused by the compounds containing oxygen atoms bleeding out due to the heat treatment and migrating to the coated surface of the substrate. The above-described specific problems can be conspicuously caused in the base material that causes such a phenomenon. From the viewpoint of effectively utilizing the advantage of this embodiment that this problem can be solved, it is preferable that Ib _{(2 nm)} and Ia _{(2 nm)} satisfy Expression (4). Although the upper limit of Ia _{(2 nm)} −Ib _{(2 nm)} is not limited, it is preferably 20% or less, more preferably 18% or less, and particularly preferably 15% from the viewpoint of effectively suppressing the coat layer from becoming mottled. % or less.

Ib is the ratio of oxygen-containing ions to all secondary ions detected at a depth of 15 nm from the coated surface when the substrate is subjected to TOF-SIMS analysis before the substrate is subjected to the heat treatment. _{(15 nm)} . In this case, Ib _{(2 nm)} and Ib _{(15 nm)} preferably satisfy the following formula (5).
|Ib _{(2 nm)} −Ib _{(15 nm)} |<5% (5)
More particularly, |Ib _{(2 nm)} −Ib _{(15 nm)} | is preferably less than 5%, more preferably less than 3%, particularly preferably less than 1%. Formula (5) is the amount of the compound containing oxygen atoms contained in the portion very close to the coated surface of the substrate and the amount of the compound containing oxygen atoms contained in the portion slightly away from the coated surface of the substrate before the substrate is subjected to heat treatment. is close to or the same as the amount of the compound containing oxygen atoms. In this way, when Ib _{(2 nm)} and Ib _{(15 nm)} of the base material before heat treatment are approximately the same, the advantage of this embodiment that the specific problem described above can be solved can be effectively utilized.

TOF-SIMS analysis can be performed using TOF-SIMS (for example, “PHInanoTOF II” manufactured by Ulvac-Phi). At this time, the following conditions can be adopted as measurement conditions.
Primary ion source: _Bi3 ⁺⁺
Secondary ion polarity: positive only Accelerating voltage: 30 kV
Measurement range: 300 µm x 300 µm
Resolution: 256 x 256
Number of scans: 16 times

A polymer having a glass transition temperature Tg is used as the polymer contained in the resin forming the base material. Although the specific glass transition temperature Tg of the polymer is not particularly limited, it is usually 85° C. or higher, preferably 88° C. or higher, particularly preferably 90° C. or higher, and usually 190° C. or lower, preferably 180° C. or lower, and particularly preferably 180° C. or lower. is below 170°C.

The glass transition temperature Tg of the polymer can be measured by the following method. First, the polymer is melted by heating in an inert atmosphere. The molten polymer is then quenched with liquid nitrogen. Subsequently, using this polymer as a test sample, a differential scanning calorimeter (DSC) can be used to measure the glass transition temperature Tg of the polymer at a heating rate of 10° C./min (heating mode). .

As the polymer contained in the resin forming the base material, a polymer containing few oxygen atoms in its molecule or a polymer containing no oxygen atom in its molecule is preferable. Among them, as the polymer contained in the resin forming the base material, a polymer whose molecule does not contain an oxygen atom is particularly preferable.

Particularly preferred polymers include polymers containing an alicyclic structure because they are excellent in mechanical strength and heat resistance. A polymer containing an alicyclic structure means a polymer having an alicyclic structure in its molecule. A polymer containing such an alicyclic structure can be, for example, a polymer obtainable by a polymerization reaction using a cyclic olefin as a monomer or a hydride thereof.

Examples of the alicyclic structure that the polymer has include a cycloalkane structure and a cycloalkene structure. Among these, a cycloalkane structure is preferable because a base material 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 polymer containing an alicyclic structure, 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. is. Heat resistance can be improved by increasing the proportion of structural units having an alicyclic structure in the polymer containing an alicyclic structure as described above. The ratio of structural units having an alicyclic structure to all structural units can be 100% by weight or less.

When the polymer containing an alicyclic structure is a hydride, the hydrogenation rate (percentage of hydrogenated main chain double bonds) in the hydrogenation reaction is preferably 98% or more, more preferably 99% or more. is. The higher the degree of hydrogenation, the better the flexibility of the polymer containing an alicyclic structure.
The hydrogenation rate of the polymer can be measured by ¹ H-NMR measurement at 145° C. using ortho-dichlorobenzene-d ⁴ as a solvent.

Moreover, the polymer contained in the resin forming the base material preferably has crystallinity from the viewpoint of effectively utilizing the advantages of the present embodiment. A "polymer having crystallinity" refers to a polymer having a melting point Tm [ie, the melting point can be observed with a differential scanning calorimeter (DSC)].

Therefore, a polymer containing an alicyclic structure and having crystallinity is particularly preferable as the polymer contained in the resin forming the base material. In the following description, a polymer containing an alicyclic structure and having crystallinity may be referred to as an "alicyclic crystalline polymer". Further, the resin containing the alicyclic crystalline polymer is sometimes referred to as "crystalline resin". A crystalline resin containing an alicyclic crystalline polymer is prone to bleed out of the components contained in the crystalline resin, and thus the above-described specific problems have remarkably occurred. Therefore, from the viewpoint of effectively utilizing the advantage of the present embodiment that this problem can be solved, the polymer is preferably an alicyclic crystalline polymer.

Examples of the alicyclic crystalline polymer include the following polymers (α) to (δ). Among these, the polymer (β) is preferable as the alicyclic crystalline polymer, since it is easy to obtain a base material having excellent heat resistance.
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 of polymer (γ) having crystallinity.

Specifically, the alicyclic crystalline polymer includes a ring-opening polymer of dicyclopentadiene having crystallinity, and a crystalline ring-opening polymer of dicyclopentadiene. is more preferred. As the alicyclic crystalline polymer, a hydrogenated ring-opening polymer of dicyclopentadiene having crystallinity is particularly preferable. 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.

Moreover, the polymer (α) and the polymer (β) can generally have higher crystallinity by increasing the degree of syndiotactic stereoregularity (ratio of racemo dyads). From the viewpoint of increasing the degree of stereoregularity of the polymer (α) and polymer (β), the proportion of racemo dyads in the structural units of polymer (α) and polymer (β) is preferably 51%. Above, more preferably 60% or more, particularly preferably 70% or more, and ideally 100%. The percentage of racemo dyads can be measured by the method described in the Examples.

As the polymer (α) to polymer (δ), polymers obtained by the production method disclosed in WO2018/062067 can be used.

When the polymer contained in the substrate has crystallinity, the melting point Tm of the polymer is preferably 200° C. or higher, more preferably 230° C. or higher, and preferably 290° C. or lower. By using a polymer having such a melting point Tm, it is possible to obtain a substrate having a better balance between moldability and heat resistance.

When the polymer contained in the substrate has crystallinity, the polymer usually has a crystallization temperature Tpc. Although the specific crystallization temperature Tpc of the polymer is not particularly limited, it is preferably 120° C. or higher and preferably 220° C. or lower.

The melting point Tm and crystallization temperature Tpc of the polymer can be measured by the following methods. First, the polymer is melted by heating in an inert atmosphere. The molten polymer is then quenched with liquid nitrogen. Subsequently, using this polymer as a test sample, a differential scanning calorimeter (DSC) was used to measure the melting point Tm and crystallization temperature Tpc of the polymer at a heating rate of 10°C/min (heating mode). measurable.

The weight average molecular weight (Mw) of the polymer contained in the substrate is preferably 1,000 or more, more preferably 2,000 or more, and preferably 1,000,000 or less, more preferably 500,000 or less. be. A 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 polymer contained in the substrate 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 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 polymer can be measured as polystyrene equivalent values by gel permeation chromatography (GPC) using tetrahydrofuran as a developing solvent.

One type of polymer may be used alone, or two or more types may be used in combination at an arbitrary ratio.

In the resin forming the substrate, the proportion of the polymer is preferably 50% by weight or more, more preferably 70% by weight or more, particularly preferably 90% by weight or more, and is usually less than 100% by weight, preferably 99% by weight. 0.8% by weight or less, more preferably 99.5% by weight or less. When the proportion of the polymer is at least the lower limit of the above range, the heat resistance of the substrate can be enhanced. Moreover, when the proportion of the polymer is less than the upper limit of the above range, the above-mentioned specific problems may occur remarkably. Therefore, from the viewpoint of effectively utilizing the advantage of this embodiment that this problem can be solved, the proportion of the polymer is preferably less than the upper limit of the range.

The resin forming the base material may contain a compounding agent containing an oxygen atom in combination with the polymer described above. The specific problems described above could arise when the resin forming the base material contains such ingredients. Therefore, from the viewpoint of effectively utilizing the advantage of the present embodiment that this problem can be solved, the resin preferably contains the compounding agent.

Compounding agents include, for example, phenolic antioxidant {e.g., (tetrakis[methylene-3-(3′,5′-di-t-butyl-4′-hydroxyphenyl)propionate]methane}, phosphorus antioxidant antioxidants such as antioxidants, sulfur antioxidants; light stabilizers such as hindered amine light stabilizers; waxes such as petroleum waxes, Fischer-Tropsch waxes and polyalkylene waxes; sorbitol compounds, metal salts of organic phosphoric acids, Nucleating agents such as metal salts of organic carboxylic acids, kaolin and talc; diaminostilbene derivatives, coumarin derivatives, azole derivatives (e.g. benzoxazole derivatives, benzotriazole derivatives, benzimidazole derivatives, and benzothiazole derivatives), carbazole derivatives, fluorescent brighteners such as pyridine derivatives, naphthalic acid derivatives, and imidazolone derivatives; UV absorbers such as benzophenone UV absorbers, salicylic acid UV absorbers, and benzotriazole UV absorbers; glass fibers; coloring agents; flame retardants; plasticizers; near-infrared absorbers; lubricants and polymer materials other than cyclic olefin ring-opening polymer hydrogenates such as soft polymers; One type may be used alone, or two or more types may be used in combination at an arbitrary ratio.

The amount of the compounding agent is arbitrary within the range in which Ia _{(2 nm)} and Ia _{(15 nm) satisfying formulas (1) and (2)} are obtained. To give an example of a specific range, the amount of the compounding agent is preferably 0.01 parts by weight or more, more preferably 0.05 parts by weight or more, and particularly preferably 0.1 parts by weight with respect to 100 parts by weight of the polymer. It is at least 10 parts by weight, preferably 10 parts by weight or less, more preferably 8 parts by weight or less, and particularly preferably 5 parts by weight or less.

Furthermore, the resin forming the base material may contain further optional ingredients in combination with the polymer and compounding agents.

When the polymer contained in the resin forming the base material has crystallinity, it is preferable that crystallization of the polymer has not progressed at the time of supplying the resin to the first step. The crystallinity of the resin at the time of supplying it to the first step is preferably 5% or less, more preferably 3% or less, and particularly preferably 1% or less. This crystallinity can be measured by an X-ray diffraction method according to JIS K0131.

There are no particular restrictions on the dimensions of the substrate. For example, when a substrate film is used as a substrate, its thickness is preferably 5 μm or more, more preferably 10 μm or more, particularly preferably 15 μm or more, and preferably 1 mm or less, more preferably 500 μm or less, and still more preferably 100 μm or less. , particularly preferably 50 μm or less.

There are no particular restrictions on the method of manufacturing the substrate. For example, when a base film is used as a base, the base film can be formed by injection molding, extrusion molding, press molding, inflation molding, blow molding, calendar molding, cast molding, compression molding. It can be manufactured by a resin molding method such as. Among these methods, the extrusion method is preferable because the thickness can be easily controlled.

[3. Coating liquid]
As the coating liquid, a liquid having surface tension within a specific range is used. Specifically, the surface tension of the coating liquid is usually 42 mN/m or less, preferably 40 mN/m or less, and particularly preferably 38 mN/m or less. By adopting a coating liquid having a low surface tension in this way, it is possible to prevent the layer of the coating liquid from becoming mottled during drying, so that a laminate having a smooth surface can be produced. The lower limit of the surface tension of the coating liquid is preferably 30 mN/m or more, more preferably 32 mN/m or more, and particularly preferably 34 mN/m or more, from the viewpoint of obtaining a coating layer with a desired thickness.

The surface tension of the coating liquid can be measured by the hanging drop method in an environment with a temperature of 23° C. and a humidity of 65%. FIG. 1 is a schematic diagram illustrating the measurement of the surface tension of a coating liquid by the hanging drop method. As shown in FIG. 1, in this hanging drop method, the surface tension can be obtained by dropping a droplet 12 from a capillary tube 11 and measuring the size of the droplet 12 . Specifically, the surface tension of the coating liquid can be obtained using the following formula (X).
γ _L = g·ρ·(de) ² H ⁻¹ (X)
(γ _L : Surface tension of the coating liquid.
g: gravitational acceleration.
ρ: Liquid density.
de: maximum droplet diameter.
H ⁻¹ : Correction term obtained from ds/de.
ds: Droplet diameter at a position a distance de above the bottom end of the liquid. )

Methods for reducing the surface tension of the coating liquid as described above include, for example, a method of adjusting the type and amount of the solvent in the coating liquid, and a coating liquid containing an appropriate type and amount of surfactant. method, etc.

A coating liquid usually contains a solid content and a solvent. As the solid content, an appropriate one can be adopted according to the composition of the coating layer provided on the laminate. Usually, the coating layer contains the above solid content or a reaction product obtained by reacting the above solid content. The solid content may be dissolved in the solvent or dispersed in the solvent. Moreover, solid content may be used individually by 1 type, and may be used in combination of 2 or more types by arbitrary ratios.

Preferred solids include, for example, polyurethanes or precursors thereof. When a coating liquid containing polyurethane or its precursor as a solid content is used in this manner, an easily adhesive layer having excellent adhesiveness can be formed as the coat layer. Either one of polyurethane and its precursor may be used, or both may be used. In particular, the coating liquid preferably contains polyurethane.

Polyurethanes can include polyurethanes derived from various polyols and polyisocyanates. Examples of polyols include polyol compounds (ethylene glycol, propylene glycol, 1,4-butanediol, neopentyl glycol, glycerin, trimethylolpropane, etc.) and polybasic acids (polycarboxylic acids (e.g., adipic acid, succinic acid, dicarboxylic acids such as acids, sebacic acid, glutaric acid, maleic acid, fumaric acid, phthalic acid, isophthalic acid, terephthalic acid, and polyvalent carboxylic acids including tricarboxylic acids such as trimellitic acid, or their anhydrides, etc.)) Aliphatic polyester-based polyol obtained by reaction; polyether polyol (e.g., poly (oxypropylene ether) polyol; poly (oxyethylene-propylene ether) polyol); polycarbonate-based polyol; and polyethylene terephthalate polyol; and mixtures thereof ; In the polyurethane, for example, hydroxyl groups remaining unreacted after the reaction between the polyol and the polyisocyanate can be used as polar groups capable of cross-linking reactions with functional groups in the cross-linking agent. Among them, as the polyurethane, a polycarbonate-based polyurethane containing a carbonate structure in its skeleton is preferable from the viewpoint of enhancing the wet heat resistance of the coat layer.

As the polyurethane, one contained in a water-based emulsion commercially available as a water-based urethane resin may be used. A water-based urethane resin is a composition containing polyurethane and water. In water-based urethane resins, polyurethane and optionally contained optional components are usually dispersed in water. Examples of water-based urethane resins include the "ADEKA BONDITTER" series manufactured by ADEKA, the "Orester" series manufactured by Mitsui Chemicals, the "Bondic" series manufactured by DIC, and the "Hydran (WLS201, WLS202, etc.)" series. , Bayer's "Impranil" series, Kao's "Poise" series, Sanyo Chemical Industries' "Samprene" series, Daiichi Kogyo Seiyaku's "Superflex" series, Kusumoto Kasei's " NEOREZ series, Lubrizol's Sancure series, and the like.

Polyurethane precursors include, for example, precursors capable of giving the various polyurethanes described above, and specific examples thereof include the above-described polyols and polyisocyanates. When a coating liquid containing these precursors is employed, a coating layer containing polyurethane can be obtained by reacting the precursors at appropriate times such as before, during, and after coating. can.

The glass transition temperature of polyurethane is preferably lower than the glass transition temperature Tg of the polymer contained in the resin forming the base material. The specific glass transition temperature range of polyurethane is preferably −20° C. or higher, more preferably −15° C. or higher, particularly preferably −10° C. or higher, preferably 50° C. or lower, more preferably 40° C. or lower. Especially preferably, it is 30° C. or less. The glass transition temperature of polyurethane can be measured by the method described in Examples.

The amount of polyurethane is preferably 60% to 100% by weight, more preferably 70% to 100% by weight, based on 100% by weight of the total solid content contained in the coating liquid.

The coating liquid may contain a cross-linking agent as a solid content. By using a cross-linking agent, polyurethane can be cross-linked, so that a coating layer having excellent mechanical strength can be obtained.

The cross-linking agent can be a compound having two or more functional groups in the molecule that can react with functional groups such as polar groups in the various polyurethanes described above to form bonds. Examples of cross-linking agents include epoxy compounds, carbodiimide compounds, oxazoline compounds, isocyanate compounds and the like, with epoxy compounds being preferred.

As the epoxy compound, a polyfunctional epoxy compound having two or more epoxy groups in the molecule is preferable from the viewpoint of obtaining a coating layer having particularly excellent mechanical strength. From the viewpoint of ease of use, the epoxy compound is preferably soluble in water or dispersible in water to emulsify.

Examples of epoxy compounds include 1 mol of glycols such as ethylene glycol, diethylene glycol, triethylene glycol, polyethylene glycol, propylene glycol, dipropylene glycol, 1,4-butanediol, 1,6-hexane glycol, and neopentyl glycol. and a diepoxy compound obtained by etherification with 2 mols of epichlorohydrin; polyhydric alcohols such as glycerin, polyglycerin, trimethylolpropane, pentaerythritol, sorbitol and 1 mol of polyhydric alcohols obtained by etherification with 2 mols or more of epichlorohydrin epoxy compounds; diepoxy compounds obtained by esterifying 1 mol of dicarboxylic acids such as phthalic acid, terephthalic acid, oxalic acid and adipic acid with 2 mol of epichlorohydrin; and the like.

More specifically, epoxy compounds include 1,4-bis(2′,3′-epoxypropyloxy)butane, 1,3,5-triglycidyl isocyanurate, 1,3-diclycidyl-5-(γ -acetoxy-β-oxypropyl) isocyanurate, sorbitol polyglycidyl ethers, polyglycerol polyglycidyl ethers, pentaerythritol polyglycidyl ethers, diglycerol polyglycidyl ether, 1,3,5-triglycidyl (2-hydroxyethyl ) Epoxy compounds such as isocyanurates, glycerol polyglycerol ethers and trimethylolpropane polyglycidyl ethers are preferred. Specific examples of commercially available products include "Denacol (Denacol EX-521, EX-614B, etc.)" series manufactured by Nagase ChemteX Corporation.

The amount of the cross-linking agent is preferably 0.1 parts by weight or more, more preferably 1 part by weight or more, particularly preferably 2 parts by weight or more, and preferably 20 parts by weight or less, or more, with respect to 100 parts by weight of the polyurethane. It is preferably 15 parts by weight or less, particularly preferably 10 parts by weight or less. When the amount of the cross-linking agent is at least the lower limit of the above range, the reaction between the cross-linking agent and the polyurethane proceeds sufficiently, so that the mechanical strength of the coat layer can be appropriately improved. Moreover, when the amount of the cross-linking agent is equal to or less than the upper limit of the above range, the residual unreacted cross-linking agent can be reduced, and the mechanical strength of the coat layer can be appropriately improved.

The coating liquid may contain, as a solid content, components other than the components described above. Such components include, for example, curing accelerators, curing aids, fine particles, heat stabilizers, weather stabilizers, leveling agents, surfactants, antioxidants, antistatic agents, slip agents, antiblocking agents, antistatic agents, Clouding agents, lubricants, dyes, pigments, natural oils, synthetic oils, waxes and the like.

As the solvent for the coating liquid, any solvent that can achieve the surface tension within the range described above can be used. Examples of solvents include water and water-soluble organic solvents. Examples of water-soluble organic solvents include methanol, ethanol, isopropyl alcohol, acetone, tetrahydrofuran, N-methylpyrrolidone, dimethylsulfoxide, ethylene glycol monomethyl ether, ethylene glycol monobutyl ether, methyl ethyl ketone, triethylamine and the like. One type of solvent may be used alone, or two or more types may be used in combination at an arbitrary ratio. The amount of the solvent is preferably set so that the viscosity of the coating liquid is within a range suitable for coating.

[4. Third step (surface modification treatment of coated surface)]
The method for manufacturing a laminate according to the present embodiment preferably includes a third step of subjecting the coated surface of the base material to a surface modification treatment prior to performing the first step. By performing this surface modification treatment, the adhesion between the substrate and the coating layer can be improved.

Examples of surface modification treatment include corona discharge treatment, plasma treatment, saponification treatment, and ultraviolet irradiation treatment. Among them, from the viewpoint of treatment efficiency, corona discharge treatment and plasma treatment are preferred, and corona discharge treatment is more preferred.

[5. First step (coating of coating solution on coated surface)]
The method for manufacturing a laminate according to the present embodiment includes the first step of applying a coating liquid to the coating surface of the substrate after performing the third step as necessary. Through this first step, a layer of the coating liquid is formed on the coated surface of the substrate.

Examples of coating methods include wire bar coating, dipping, spraying, spin coating, roll coating, gravure coating, air knife coating, curtain coating, slide coating, and extrusion coating. mentioned.

The coating amount per unit area can be appropriately set according to the thickness of the coat layer. As a specific range, the coating amount of the coating liquid per 1 m ² of the coated surface of the substrate is preferably 0.5 mL or more, preferably 1 mL or more, particularly preferably 1.5 mL or more, and preferably It is 20 mL or less, more preferably 15 mL or less, and particularly preferably 10 mL or less. Moreover, when the coating liquid is applied in such a coating amount, the effect of the present invention can be effectively utilized.

[6. Second step (drying of coating liquid layer)]
The method for manufacturing a laminate according to the present embodiment includes a second step of drying the layer of the coating liquid formed on the coating surface of the substrate after the first step. This second step removes the solvent from the layer of the coating liquid to form a coating layer containing the solid content of the coating liquid or its reaction product. Therefore, it is possible to obtain a laminate comprising a substrate and a coat layer. Components contained in the substrate may bleed out onto the coated surface during drying, but even if such bleeding occurs, the layer of the coating liquid can be uniformly fixed on the coated surface of the substrate. Therefore, the coat layer can be prevented from becoming mottled, and the surface of the laminate can be made smooth.

Any drying method may be used, and any method such as drying under reduced pressure or drying by heating may be used. Among them, it is preferable to perform drying by heating from the viewpoint of rapidly advancing reactions such as crosslinking reaction of the solid content together with drying.

The specific drying temperature in the second step is preferably Tg-10°C or higher, more preferably Tg-8°C or higher, particularly preferably Tg-5°C or higher, preferably Tg+10°C or lower, more preferably Tg+5°C. Below, Tg+2° C. or less is particularly preferable. Tg represents the glass transition temperature of the polymer contained in the resin forming the substrate. When the drying temperature is within the above range, drying can be performed quickly. Moreover, when a coating liquid containing a cross-linking agent is used, the cross-linking reaction can proceed smoothly. Furthermore, when the drying temperature is within the above range, the specific problems described above can be remarkably caused. Therefore, from the viewpoint of effectively utilizing the advantage of this embodiment that this problem can be solved, it is preferable that the drying temperature is within the above range.

The drying time in the second step is not particularly limited, and can be, for example, 5 seconds to 5 minutes.

The thickness of the coat layer to be formed is not particularly limited, and is arbitrary according to the properties required for the coat layer. Specifically, the thickness of the coating layer is preferably 100 nm or more, more preferably 150 nm or more, particularly preferably 180 nm or more, preferably 5 μm or less, more preferably 2 μm or less, and particularly preferably 1 μm or less. be.

[7. Fourth step (stretching)]
The method for manufacturing a laminate according to the present embodiment may include a fourth step of stretching the obtained laminate after the second step. By stretching, the thickness of the laminate can be reduced and the optical properties (retardation, etc.) of the laminate can be adjusted.

The stretching temperature is preferably Tg-30°C or higher, more preferably Tg-10°C or higher, and preferably Tg+60°C or lower, more preferably Tg+50°C or lower. By stretching in such a temperature range, the polymer molecules contained in the substrate can be properly oriented. Tg represents the glass transition temperature of the polymer contained in the resin forming the substrate.

The draw ratio can be appropriately selected depending on factors such as desired optical properties, thickness and strength, and is usually greater than 1-fold, preferably 1.01-fold or more, and usually 10-fold or less, preferably 5-fold or less. is. Here, when the film is stretched in a plurality of different directions such as biaxial stretching, the stretch ratio represents the total stretch ratio represented by the product of the stretch ratios in each stretching direction.

[8. Fifth step (crystallization)]
When the polymer contained in the base material has crystallinity, the method for producing a laminate according to the present embodiment includes, after the second step, a fifth step of performing a crystallization treatment to advance the crystallization of the polymer. you can go When the method for manufacturing a laminate includes the fourth step, the fifth step is usually performed after the fourth step.

Crystallization treatment is usually performed by heating the laminate to a specific temperature range. Here, the above temperature range is usually higher than the glass transition temperature Tg of the polymer and lower than the melting point Tm of the polymer. More specifically, the temperature range of the crystallization treatment is preferably Tg+20°C or higher, more preferably Tg+30°C or higher, and preferably Tm-20°C or lower, more preferably Tm-40°C or lower. Within the above temperature range, crystallization of the polymer can be rapidly progressed while suppressing white turbidity of the base material due to progress of crystallization.

During the crystallization treatment, the treatment time for maintaining the laminate in the above temperature range is preferably 1 second or longer, more preferably 5 seconds or longer, and preferably 30 minutes or shorter, more preferably 10 minutes or shorter.

The crystallization treatment is preferably performed while holding at least two sides of the laminate so that the laminate is not deformed by heat shrinkage. "A state in which at least two sides of the laminated body are held" means a state in which the laminated body is held by a holder to such an extent that the laminated body is not flexed. In such conditions, the laminate is normally in tension with appropriate tension. However, this condition does not include holding conditions in which the laminate is substantially stretched. Further, "substantially stretched" means that the stretch ratio in any direction of the laminate is usually 1.03 times or more.

Crystallization is preferably carried out to such an extent that the degree of crystallinity of the resin forming the substrate reaches a desired value. The degree of crystallinity of the resin after crystallization is preferably 30% or more, more preferably 50% or more, and particularly preferably 60% or more. The upper limit of crystallinity can be, for example, 100% or less, 90% or less, or 80% or less. When the degree of crystallinity is high as described above, the flex resistance and chemical resistance of the laminate can be improved.

[9. Other processes]
The method for manufacturing a laminate according to the present embodiment may include other steps in combination with the steps described above. For example, the method for producing a laminate may include a step of subjecting the surface of the coat layer to a surface modification treatment after forming the coat layer in the second step. Moreover, the method for manufacturing a laminate may include, after the fifth step, a step of thermally shrinking the base material to remove residual stress in the base material. Furthermore, the laminate may include a step of forming another layer.

[10. Laminate to be manufactured]
According to the manufacturing method described above, it is possible to manufacture a laminate including a base material and a coat layer formed on the base material. The coat layer is usually in direct contact with the substrate. Here, "directly" in which the base material and the coat layer are in contact means that there is no other layer between the base material and the coat layer. Further, when the substrate is a substrate film, according to the above-described production method, not only the laminate having the coat layer on one coated surface of the substrate film, but also the coat layers on both coated surfaces of the substrate film. It is also possible to obtain a laminate comprising

According to the manufacturing method described above, a coat layer can be uniformly formed on the coating surface of the substrate. Therefore, it is possible to prevent the coat layer from being partially chipped and becoming patchy, and the thickness of the coat layer from becoming uneven. Therefore, the surface of the laminate can be made smooth.

It is preferable that the laminate have characteristics according to the application of the laminate. For example, if a substrate film is used as the substrate, a film-like laminate can be obtained. When this film-like laminate is used as an optical film, the laminate preferably has high transparency. Specifically, the total light transmittance of the laminate is preferably 80% or higher, more preferably 85% or higher, and particularly preferably 88% or higher. Total light transmittance can be measured in the wavelength range of 400 nm to 700 nm using an ultraviolet-visible spectrometer.

A laminated body can be used for arbitrary uses. For example, film-like laminates are suitable as optical films such as optical isotropic films and retardation films; electrical and electronic films; support films for barrier films; and support films for conductive films. Examples of the optical film include retardation films for liquid crystal display devices, polarizing plate protective films, and retardation films for circularly polarizing plates of organic EL display devices. Electrical and electronic films include, for example, flexible wiring substrates, insulating materials for film capacitors, and the like. Examples of barrier films include substrates for organic EL devices, sealing films, sealing films for solar cells, and the like. Examples of conductive films include flexible electrodes of organic EL elements and solar cells, touch panel members, and the like.

EXAMPLES Hereinafter, the present invention will be specifically described 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 description, "%" and "parts" representing amounts are by weight unless otherwise specified. In addition, unless otherwise specified, the operations described below were performed under normal temperature and pressure conditions.

[Evaluation method]
(Method for measuring weight average molecular weight and number average molecular weight of polymer)
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. Moreover, the temperature at the time of 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.

(Measurement method of glass transition temperature Tg, melting point Tm and crystallization temperature Tpc of polymer)
A sample heated to 300° C. under a nitrogen atmosphere was quenched with liquid nitrogen. Then, using a differential scanning calorimeter (DSC), the temperature was raised at 10° C./min to determine the glass transition temperature Tg, melting point Tm and crystallization temperature Tpc of the sample.

(Method for Measuring Ratio of Racemo Diad in Polymer)
¹³ C-NMR measurement of the polymer was performed using ortho-dichlorobenzene-d ⁴ as a solvent at 200° C. and applying the inverse-gated decoupling method. In the results of this ¹³ C-NMR measurement, with the 127.5 ppm peak of ortho-dichlorobenzene-d ⁴ as the standard shift, the 43.35 ppm signal derived from the meso dyad and the 43.43 ppm signal derived from the racemo dyad. identified. Based on the intensity ratio of these signals, the proportion of racemo dyads in the polymer was determined.

(Method for measuring crystallinity of resin)
The crystallinity of the resin was confirmed by X-ray diffraction according to JIS K0131. Specifically, using a wide-angle X-ray diffractometer (“RINT 2000” manufactured by Rigaku Corporation), the diffraction X-ray intensity from the crystallized portion is obtained, and the ratio to the entire diffraction X-ray intensity is calculated using the following formula: Crystallinity was determined by (I).
Xc=K·Ic/It (I)
In the above formula (I), Xc represents the degree of crystallinity of the sample, Ic represents the diffracted X-ray intensity from the crystallized portion, It represents the overall diffracted X-ray intensity, and K represents the correction term.

(TOF-SIMS analysis method)
The surface of the base film was analyzed by TOF-SIMS ("PHInanoTOF II" manufactured by ULVAC-PHI). The measurement conditions described above were adopted as the analysis conditions. In this analysis, information on the elemental composition distribution in the depth direction was obtained by advancing the analysis while etching the surface of the substrate film. Further, according to the above analysis, information on secondary ions emitted from the substrate film was obtained at each portion in the depth direction of the substrate film.

In Examples, Comparative Examples, and Reference Examples, which will be described later, C ₁₅ H ₂₃ O ⁺ was detected as secondary ions corresponding to oxygen-containing ions. This is an ion derived from an antioxidant ("Irganox (registered trademark) 1010" manufactured by BASF Japan).
In Examples, Comparative Examples, and Reference Examples, which will be described later, hydrocarbon ions were detected as secondary ions corresponding to ions containing no oxygen. This is an ion derived from a polymer (base polymer) other than the antioxidant contained in the base film.
The detected intensity of oxygen-containing ions was normalized as a percentage of the total detected intensity of hydrocarbon ions. Based on the information obtained by normalization, the ratio of oxygen-containing ions when all secondary ions (that is, the sum of oxygen-containing ions and hydrocarbon ions) released from the base film is 100%, Calculated on a number basis.

(Method for measuring glass transition temperature of urethane resin)
The coating liquid containing the urethane resin was poured into a container treated with Teflon (registered trademark) and dried at room temperature for 24 hours. After that, it was dried in an oven at 120° C. for an additional hour to prepare a urethane resin layer having a thickness of 150 μm. The glass transition temperature of this layered product was measured from the tan δ peak using a dynamic viscoelasticity measuring device ("Rheogel-E4000" manufactured by UBM). At this time, when two peaks appeared, the peak with the lower temperature was adopted as the glass transition temperature.

(Method for measuring surface tension of liquid)
The surface tension of a liquid such as a coating liquid was measured by the hanging drop method using a surface tensiometer (“Drop Master DM500” manufactured by Kyowa Interface Science Co., Ltd.) in an environment of 23° C. temperature and 65% humidity. Specifically, the coating liquid prepared in each example and comparative example is used as a liquid for measuring surface tension, and the above-mentioned formula (X) is used by the hanging drop method using the surface tension meter. The surface tension of the liquid was determined.

(Method for measuring the thickness of each layer contained in the film)
The thickness of each layer constituting the film was measured as follows. The refractive index of each layer of the sample film was measured using ellipsometry ("M-2000" manufactured by Woollam Co.). After that, using the measured refractive index, the thickness was measured with an optical interference film thickness meter (“MCPD-9800” manufactured by Otsuka Electronics Co., Ltd.).

[Production Example 1. Production of hydride of ring-opening polymer of dicyclopentadiene]
After sufficiently drying the metal pressure-resistant reactor, the atmosphere was replaced with nitrogen. Into this pressure-resistant reactor, 154.5 parts of cyclohexane, 42.8 parts of a 70% cyclohexane solution of dicyclopentadiene (endo body content of 99% or more) (30 parts as the amount of dicyclopentadiene), and 1-hexene 1.9 parts was added and warmed to 53°C.

To a solution of 0.014 parts of tetrachlorotungstenphenylimide (tetrahydrofuran) complex dissolved in 0.70 parts of toluene, 0.061 parts of a 19% diethylaluminum ethoxide/n-hexane solution was added and stirred for 10 minutes. to prepare a catalyst solution.
This catalyst solution was added to the pressure reactor to initiate the 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 number average molecular weight (Mn) and weight average molecular weight (Mw) of the resulting ring-opened dicyclopentadiene polymer were 8750 and 28,100, respectively, and the molecular weight distribution (Mw/Mn) obtained from these 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 parts of a filter aid (“Radiolite (registered trademark) #1500” manufactured by Showa Chemical Industry Co., Ltd.) was added, and a PP pleated cartridge filter (“TCP-HX” manufactured by ADVANTEC Toyo Co., Ltd.) was 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, and 0.0043 parts of chlorohydridocarbonyltris(triphenylphosphine)ruthenium was further added, A hydrogenation reaction was carried out at a hydrogen 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 94°C, a melting point (Tm) of 262°C, a crystallization temperature Tpc of 170°C, and a ratio of racemo diads of 89%.

[Example 1]
(1-1. Production of base film)
To 100 parts of the hydride of the ring-opening polymer of dicyclopentadiene obtained in Production Example 1, an antioxidant (tetrakis[methylene-3-(3′,5′-di-t-butyl-4′-hydroxyphenyl) propionate]methane; manufactured by BASF Japan Ltd., "Irganox (registered trademark) 1010") was mixed with 0.5 parts to obtain a crystalline resin A as a material for the base film.

Crystalline resin A was put into a twin-screw extruder (“TEM-37B” manufactured by Toshiba Machine Co., Ltd.) equipped with four die holes with an inner diameter of 3 mmΦ. The crystalline resin A was molded into a strand-like molding by hot-melt extrusion molding using the twin-screw extruder. This compact was cut into small pieces with a strand cutter to obtain crystalline resin A pellets.

The resulting pellets were subsequently fed to a hot-melt extrusion film former equipped with a T-die. A long film (width 120 mm) was manufactured by a method of extruding the crystalline resin A onto a cast roll through a die of this film forming machine and winding it on a roll at a speed of 27 m/min. The operating conditions of the film forming machine are shown below.
・Barrel temperature setting: 280°C to 290°C
・Die temperature: 270°C
・Screw rotation speed: 30 rpm
・Cast roll temperature: 70°C

As a result, a substrate film was obtained as a long crystalline resin A film. The thickness of the obtained base film was 20 μm. The crystallinity of the crystalline resin A contained in this base film was 0.7%.

TOF-SIMS analysis is performed on the obtained base film to measure the proportions of oxygen-containing ions Ib _{(2 nm)} and Ib _{(15 nm)} detected at depths of 2 nm and 15 nm from the surface of the base film. did. As a result of the measurement, the percentage of oxygen-containing ions Ib _{(2 nm)} detected at a depth of 2 nm was 1%, and the percentage of oxygen-containing ions Ib _{(15 nm) detected at a depth of 15 nm} was 0.5%. there were.

After that, the base film was subjected to a heat treatment of heating at a temperature of 90° C. for 30 seconds.
After that, TOF-SIMS analysis is performed on the heat-treated base film, and the ratio of oxygen-containing ions Ia _{(2 nm)} and Ia detected at depths of 2 nm and 15 nm from the surface of the base film _{(15 nm)} was measured. As a result of the measurement, the ratio Ia _{(2 nm)} of oxygen-containing ions detected at a depth of 2 nm was 10%, and the ratio Ia _{(15 nm) of oxygen-containing ions detected at a depth of 15 nm} was 0.5%. there were.

(1-2. Preparation of coating solution)
Aqueous dispersion of carbonate-based polyurethane (ADEKA Co., Ltd. "Adeka Bontiter SPX0672", glass transition temperature -16 ° C.) as the main component is 100 parts of polyurethane, and a polyfunctional epoxy compound (Nagasechem) is used as a cross-linking agent. 2.7 parts of "Denacol EX521" manufactured by Tex Co., Ltd., and ethanol and ion-exchanged water as solvents were blended to obtain a coating liquid containing a urethane resin. The amount of ethanol was set so that the amount of ethanol was 10% by weight with respect to 100% by weight of the total amount of the coating liquid. The amount of ion-exchanged water was set so that the total concentration of the polyurethane and the cross-linking agent as solids contained in the coating liquid was 10%. The surface tension of the obtained coating liquid was 42 mN/m.

(1-3. Coating and drying of coating liquid on base film)
Using a corona treatment apparatus (manufactured by Kasuga Denki Co., Ltd.), the surface of the base film before heat treatment was subjected to discharge treatment under the conditions of an output of 500 W, an electrode length of 1.35 m, and a conveying speed of 15 m/min. .
The coating liquid was applied to the surface of the substrate film subjected to such discharge treatment using a roll coater. The coating thickness was adjusted so that the thickness after drying was a desired value. Thereby, a layer of the coating liquid was formed on the base film (first step).
Subsequently, the layer of the coating liquid on the substrate film was dried (second step). Drying was performed under the conditions of a drying temperature of 90° C. and a drying time of 120 seconds. By this drying, a urethane resin layer was formed as an easy-adhesion layer on the base film, and a long intermediate film including the base film and the easy-adhesion layer was obtained. The thickness of the easy-adhesion layer in the resulting intermediate film was 200 nm.

(1-4. Crystallization of resin contained in base film)
The long intermediate film was cut to obtain a square film piece of 350 mm×350 mm. This cutting was performed so that each square edge of the cut film piece was parallel to the longitudinal direction or width direction of the long intermediate film. Then, the cut film pieces were placed on a small stretching machine (“EX10-B type” manufactured by Toyo Seiki Seisakusho Co., Ltd.) so that both sides of the film pieces were horizontal. This compact stretching machine has a plurality of clips capable of gripping the four edges of the film piece, and has a structure in which the film piece can be held without shrinkage by gripping the film piece with these clips.

A crystallization treatment was performed by heating a piece of film placed in a small stretching machine to promote crystallization. This treatment was carried out by bringing the secondary heating plate attached to the small stretching machine close to the upper and lower surfaces of the film piece while holding the four edges of the film piece for 30 seconds. Ta. At this time, the temperature of the secondary heating plate was set to 170° C., and the distance between the film piece and the secondary heating plate was set to 8 mm at the top and bottom. As a result, the crystallization of the hydride of the ring-opening polymer of dicyclopentadiene progressed, and the degree of crystallinity of the crystalline resin contained in the base film of the film piece increased. The crystallinity of this crystalline resin was measured and found to be 71%.

As described above, an optical film as a laminate including a base film made of a crystalline resin having a high degree of crystallinity and an easy-adhesion layer formed on the base film was obtained.
Visual observation of the surface of the easy-adhesion layer side of the obtained optical film revealed no surface defects, and the surface was smooth. Therefore, the easy-adhesion layer could be uniformly formed on the base film. was confirmed.

[Example 2]
In the above step (1-2), the amount of ethanol was changed to 40% by weight with respect to 100% by weight of the total amount of the coating liquid.
An optical film as a laminate was produced in the same manner as in Example 1 except for the above items. The surface tension of the coating liquid used in Example 2 was 37 mN/m. In addition, when the surface of the obtained optical film on the easy-adhesion layer side was visually observed, no surface defects were observed, and the surface was smooth. Therefore, the easy-adhesion layer was uniformly formed on the base film. Confirmed that it worked.

[Example 3]
Aqueous dispersion of carbonate-based polyurethane (ADEKA Co., Ltd. "Adeka Bontiter SPX0672", glass transition temperature -16 ° C.) as the main component is 100 parts of polyurethane, and a polyfunctional epoxy compound (Nagasechem) is used as a cross-linking agent. 2.7 parts of "Denacol EX521" manufactured by Tex Co., Ltd.), acetylene glycol as a surfactant ("Surfinol 440" manufactured by Nissin Chemical Industry Co., Ltd.), and deionized water as a solvent are blended to form a urethane resin. A coating solution containing The amount of surfactant was set so that the amount of surfactant was 0.3% by weight with respect to 100% by weight of the total water content of the coating liquid. In this operation, the "total amount of water" is the total amount of the water contained in the water dispersion of polyurethane and the added ion-exchanged water. The amount of ion-exchanged water was set so that the total concentration of polyurethane, cross-linking agent and surfactant as solids contained in the coating liquid was 10%. The surface tension of the obtained coating liquid was 34 mN/m.

An optical film as a laminate was produced in the same manner as in Example 1 except that the coating liquid prepared in Example 3 was used instead of the coating liquid prepared in Example 1. . Visual observation of the surface of the easy-adhesion layer side of the obtained optical film revealed no surface defects, and the surface was smooth. Therefore, the easy-adhesion layer could be uniformly formed on the base film. was confirmed.

[Example 4]
The amount of acetylene glycol (“Surfinol 440” manufactured by Nissin Chemical Industry Co., Ltd.) as a surfactant was changed to 0.5% by weight with respect to 100% by weight of the total water content. An optical film as a laminate was produced in the same manner as in Example 3 except for the above items. The surface tension of the coating liquid used in Example 4 was 31 mN/m. In addition, when the surface of the obtained optical film on the easy-adhesion layer side was visually observed, no surface defects were observed, and the surface was smooth. Therefore, the easy-adhesion layer was uniformly formed on the base film. Confirmed that it worked.

[Comparative Example 1]
The amount of acetylene glycol (“Surfinol 440” manufactured by Nissin Chemical Industry Co., Ltd.) as a surfactant was changed to 0.18% by weight with respect to 100% by weight of the total water content. An optical film as a laminate was produced in the same manner as in Example 3 except for the above items. The surface tension of the coating liquid used in Comparative Example 1 was 43 mN/m. In addition, when the surface of the optical film on the easy-adhesion layer side was visually observed, it was confirmed that the easy-adhesion layer could not be uniformly formed because the surface was not smooth, with patchy defects occurring. .

[Comparative Example 2]
Acetylene glycol (“Surfinol 440” manufactured by Nissin Kagaku Kogyo Co., Ltd.) was not used as a surfactant. An optical film as a laminate was produced in the same manner as in Example 3 except for the above items. The surface tension of the coating liquid used in Comparative Example 2 was 48 mN/m. In addition, when the surface of the optical film on the easy-adhesion layer side was visually observed, it was confirmed that the easy-adhesion layer could not be uniformly formed because the surface was not smooth, with patchy defects occurring. .

[Reference example 1]
An amorphous cycloolefin resin film (“ZF16” manufactured by Nippon Zeon Co., Ltd., glass transition temperature Tg=163° C.) was prepared.
This cycloolefin resin film was subjected to heat treatment at a temperature of 160° C. for 30 seconds. TOF-SIMS analysis is performed on the heat-treated cycloolefin resin film, and the ratio of oxygen-containing ions Ia _{(2 nm)} and Ia _{(15 nm)} detected at depths of 2 nm and 15 nm from the surface of the film. was measured. As a result of the measurement, the ratio Ia _{(2 nm)} of oxygen-containing ions detected at a depth of 2 nm was 1%, and the ratio Ia _{(15 nm) of oxygen-containing ions detected at a depth of 15 nm} was 0.5%. there were.

An optical film as a laminate was produced in the same manner as in Comparative Example 1, except that the cycloolefin resin film before heat treatment was used instead of the base film. Visual observation of the surface of the easy-adhesion layer side of the obtained optical film revealed no surface defects, and the surface was smooth. Therefore, the easy-adhesion layer could be uniformly formed on the base film. was confirmed.

[result]
The results of the above examples, comparative examples and reference examples are shown in the table below. Abbreviations used in the following description have the following meanings.
A: Film of crystalline resin A.
ZF: Amorphous cycloolefin resin film.

11 tubule 22 droplet

Claims (5)

a first step of applying a coating liquid having a surface tension of 42 mN/m or less to the surface of a substrate formed of a resin containing a polymer to form a layer of the coating liquid;
and a second step of drying the layer of the coating liquid,
the polymer has a glass transition temperature Tg, contains an alicyclic structure, and has crystallinity;
After subjecting the base material to heat treatment for 30 seconds at a temperature of Tg-4 ° C. to Tg-3 ° C., when TOF-SIMS analysis was performed on the base material, a depth of 2 nm from the surface and The ratios Ia _{(2 nm)} and Ia _{(15 nm) of oxygen-containing ions to all secondary ions detected at a depth of 15 nm} are expressed by the following formulas (1) and (2):
Ia _{(2 nm)} ≧3% (1)
Ia _{(2 nm)} >Ia _{(15 nm)} (2)
A method for manufacturing a laminate that satisfies The method for producing a laminate according to claim 1, wherein the coating liquid contains polyurethane. The method for producing a laminate according to claim 1 or 2, wherein the drying temperature in the second step is Tg-10°C or higher and Tg+10°C or lower. The Ia _{(15 nm)} is represented by the following formula (3):
Ia _{(15 nm)} ≤ 1% (3)
The method for producing a laminate according to any one of claims 1 to 3 , which satisfies When TOF-SIMS analysis is performed on the substrate before the substrate is subjected to the heat treatment, the ratio of oxygen-containing ions to all secondary ions detected at a depth of 2 nm from the surface _{Ib ( 2 nm)} and said Ia _{(2 nm)} are represented by the following formula (4):
Ia _{(2 nm)} >Ib _{(2 nm)} (4)
The method for producing a laminate according to any one of claims 1 to 4 , which satisfies

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