CN110891783A

CN110891783A - Protective film laminate and functional film

Info

Publication number: CN110891783A
Application number: CN201880047286.5A
Authority: CN
Inventors: 古屋拓己; 泉达矢; 大西乡; 岩屋涉
Original assignee: Lintec Corp
Current assignee: Lintec Corp
Priority date: 2017-07-28
Filing date: 2018-07-26
Publication date: 2020-03-17
Also published as: TW201917015A; WO2019022208A1; KR102575801B1; JP7280186B2; KR20200035912A; JPWO2019022208A1; TWI782064B

Abstract

The invention provides a protective film laminate (P) (101) for an amorphous film, which is formed by laminating protective films (1) (11) and protective films (2) (12), and also provides a functional film (1) which is a laminate formed by laminating an amorphous film (10) on the protective film (2) side of the protective film laminate (P) (101).

Description

Protective film laminate and functional film

Technical Field

The present invention relates to a protective film laminate for an amorphous film and a functional film having the protective film laminate.

Background

In recent years, the use of transparent plastic films has been studied as optical films used for optical device members such as Liquid Crystal Displays (LCDs) and Electroluminescence (EL) displays. As such a plastic film, an amorphous film made of an amorphous resin is used from the viewpoint of optical characteristics such as transparency and in-plane retardation.

Since such an amorphous film is brittle and easily scratched, it is generally used or stored as a laminate having a protective film provided at least on a surface of the amorphous film which comes into contact with a device or the like, for use in a transportation step or a processing step, or for protection during storage.

For example, patent document 1 discloses a transparent conductive film laminate including: the transparent conductive film laminate comprises a carrier film having an adhesive layer on at least one surface side of a protective film, and a transparent conductive film which is laminated so as to be peelable with the adhesive layer interposed therebetween, and satisfies specific conditions relating to a specific composition and a curl value. In the carrier film described in patent document 1, the transparent resin film in the transparent conductive film contains an amorphous cycloolefin resin, and the protective film needs to be formed of an amorphous resin that is different from the amorphous cycloolefin resin and has a glass transition temperature of 130 ℃.

Documents of the prior art

Patent document

Patent document 1: japanese patent laid-open publication No. 2016-107503

Disclosure of Invention

Problems to be solved by the invention

As described above, an amorphous film used as a member for an optical device may be used as a member for an optical device after being formed into a laminate in which layers having various functions are further laminated on the amorphous film. In the production of the optical device member, the laminate may be subjected to a treatment such as a heat treatment. For example, when an amorphous film is used as one member of a transparent conductive film or the like, the following are listed: a heat treatment in a step of bonding the amorphous film and another member included in the laminate using a thermosetting adhesive or the like, an annealing treatment performed to crystallize the transparent conductive film after the transparent conductive film is laminated on the amorphous film, or the like.

Therefore, the above laminate has a problem that the protective film is deformed seriously if the amorphous film is not protected by an appropriate protective film in the case of being exposed to a high-temperature environment or in the case of being used in a room-temperature environment after being exposed to a high-temperature environment. In this way, when the protective film itself is deformed, a problem occurs in that the laminate including the amorphous film is severely curled. If the laminate including the amorphous film is curled seriously, conveyance failure, processing failure, and the like occur in the subsequent steps, which causes problems such as failure at the time of production, reduction in productivity such as reduction in yield, and the like.

Here, the protective film formed of an amorphous resin described in patent document 1 has a risk of blocking when used under high temperature conditions. In addition, since the protective film itself is an amorphous resin, there is a risk that the protective film is broken due to brittleness. Further, there is an economic disadvantage that the price of the protective film made of an amorphous resin is very high.

The present invention has been made in view of the above circumstances, and an object thereof is to provide a functional film capable of suppressing curling even when exposed to a high-temperature environment, and a protective film laminate for an amorphous film used for the functional film.

Means for solving the problems

The present inventors have found that the above problems can be solved by using a laminate (P) in which a protective film (1) and a protective film (2) are laminated (hereinafter, also simply referred to as "laminate (P)") as a film for protecting an amorphous film, and have completed the present invention.

Namely, the present invention provides the following [1] to [15 ].

[1] A protective film laminate (P) for an amorphous film is obtained by laminating a protective film (1) and a protective film (2).

[2] The protective film laminate for an amorphous film according to [1], wherein the protective film (1) and the protective film (2) are protective films made of different materials.

[3] The protective film laminate for an amorphous film according to [1] or [2], wherein at least one of the protective film (1) and the protective film (2) comprises a base film and a pressure-sensitive adhesive layer (Y).

[4] The protective film laminate for an amorphous film according to any one of [1] to [3], wherein the tensile storage modulus E 'of the protective film (1) at 23 ℃ is lower than the tensile storage modulus E' of the protective film (2) at 23 ℃.

[5]Above-mentioned [1]～[4]The protective film laminate for an amorphous film, wherein the protective film (1) has a tensile storage modulus E' of 1.0X 10 at 23 ℃⁷Pa is not less than 3.0X 10⁹Pa, the tensile storage modulus E' of the protective film (2) at 23 ℃ is 3.0X 10⁹Pa or more and 1.0X 10¹¹Pa or less.

[6] The protective film laminate for an amorphous film according to any one of [1] to [5], wherein the protective film (1) is a polyolefin protective film.

[7] The protective film laminate for an amorphous film according to any one of [1] to [6], wherein the protective film (2) is a polyester-based protective film.

[8] The protective film laminate for an amorphous film according to any one of [1] to [7], wherein the protective film (1) is a polyolefin protective film and the protective film (2) is a polyester protective film.

[9] A functional film which is a laminate comprising an amorphous film laminated on the side of the protective film (2) of the protective film laminate for an amorphous film according to any one of the above [1] to [8 ].

[10] The functional film according to [9], further comprising a binder layer (X) between the protective film laminate (P) and the amorphous film.

[11] The functional film according to the above [9] or [10], wherein the thickness of the protective film (1) is 0.3 to 1.5 times the thickness of the amorphous film.

[12] The functional film according to any one of the above [9] to [11], wherein the thickness of the protective film laminate (P) is 2 μm or more and 300 μm or less.

[13] The functional film according to any one of the above [9] to [12], wherein the amorphous film is at least 1 selected from a cycloolefin film and a polycarbonate film.

[14] The functional film according to any one of [9] to [13], wherein the amorphous film has a thickness of 1 μm or more and 100 μm or less.

[15] The functional film according to any one of the above [9] to [14], which is used for an optical device.

ADVANTAGEOUS EFFECTS OF INVENTION

According to the present invention, a functional film capable of suppressing curling even when exposed to a high-temperature environment, and a protective film laminate for an amorphous film used for the functional film can be provided.

Drawings

Fig. 1 is a sectional view of a functional film 1 as an example of the functional film of the present invention.

Fig. 2 is a sectional view of a functional film 2 as an example of the functional film of the present invention.

Description of the symbols

1.2 functional film

10 amorphous film

11 protective film (1)

12 protective film (2)

101 protective film laminate (P)

13 adhesive layer (X)

Detailed Description

The present invention will be described in detail below with reference to embodiments.

In the present specification, the lower limit and the upper limit recited in the stepwise manner may be independently combined for a preferable numerical range (for example, a range of contents). For example, according to the description of "preferably 10 to 90, more preferably 30 to 60", the "preferable lower limit value (10)" and the "more preferable upper limit value (60)" may be combined to obtain "10 to 60". Similarly, the combination of the "preferable lower limit value (10)" and the "more preferable upper limit value (60)" may be made to be "10 or more and 60 or less" in accordance with the description of "preferably 10 or more, more preferably 30 or more" and the description of "preferably 90 or less, more preferably 60 or less" of the same matter.

In the present specification, the term "protective film" is used as a term indicating a film used for protecting an adherend such as an "amorphous film" as described above.

In addition, in this specification. "(meth) acrylic acid" is used as a term to indicate either or both of "acrylic acid" or "methacrylic acid". Likewise, "(meth) acrylate" is used as a term to denote either or both of "acrylate" or "methacrylate".

[ functional film ]

The functional film according to one embodiment of the present invention is a laminate including a protective film laminate (P) according to one embodiment of the present invention, in which an amorphous film is laminated on the protective film (2) side of the laminate (P), and the protective film laminate (P) is formed by laminating a protective film (1) and a protective film (2).

The present inventors have found that by using the laminate (P) as a film for protecting an amorphous film, a functional film capable of suppressing curling even when exposed to a high-temperature environment can be provided.

< construction of functional Membrane >

Examples of the structure of the functional film include those shown in fig. 1 and 2, but the structure is not limited thereto.

Fig. 1 is a cross-sectional view of a functional film 1 as an example of an embodiment of the functional film of the present invention, and the functional film 1 is a laminate in which an amorphous film 10 is laminated on the protective film (2)12 side of a protective film laminate (P)101 in which a protective film (1)11 and a protective film (2)12 are laminated.

Examples of the method for producing the functional film 1 of this embodiment include: a method of bonding the protective film (2)12 to the amorphous film 10 and further bonding the protective film (1)11 to the surface of the protective film (2)12 opposite to the amorphous film 10. In addition, examples thereof include: a method for producing a protective film laminate (P)101 in which a protective film (1)11 is bonded to a protective film (2)12, and for bonding an amorphous film 10 to the surface side of the protective film (2)12 of the laminate (P) 101.

In addition, examples thereof include: a method of forming the amorphous film 11 by directly applying a raw material resin for forming the amorphous film 11 on the side of the protective film (2)12 of the laminate (P)101 obtained by previously bonding the protective films (1)11 and (2)12 and drying the applied raw material resin. In addition, examples thereof include: a method for forming the protective film (1)11 by co-extruding the resin forming the protective film (1)11 and the resin forming the protective film (2)12 to form a laminate (P)101, wherein the protective film (2)12 side is directly coated with a raw material resin solution for forming the amorphous film (11), and then dried. In addition, examples thereof include: and a method of directly molding the functional film 1 having the laminate (P)101 and the amorphous film 10 by co-extruding the resin forming the protective film (1)11, the resin forming the protective film (2)12, and the resin forming the amorphous film 10.

After the protective film (2)12 and the amorphous film 10 are laminated by the above-described method (bonding, coextrusion molding), the protective film (1)11 may be formed on the surface of the protective film (2)12 opposite to the amorphous film 10.

Fig. 2 is a cross-sectional view of a functional film 2 as an example of the embodiment of the functional film of the present invention, and the functional film 2 is a laminate in which a protective film (1)11, a protective film (2)12, an adhesive layer (X)13, and an amorphous film 10 are directly laminated in this order. As shown in fig. 2, the amorphous film 10 and the protective film (2)12 are directly laminated together via the adhesive layer (X) 13.

Examples of the method for producing the functional film 2 of this embodiment include the following: by using the method (bonding, co-extrusion molding) described in the example of the method for producing the functional film 1, the pressure-sensitive adhesive layer (X)13 is provided on the protective film (2)12 side of the laminate (P)101 prepared in advance, the amorphous film 10 prepared in advance is laminated on the exposed surface of the pressure-sensitive adhesive layer (X)13, and the lamination is performed using a laminator or the like. Alternatively, the following methods may be cited: the pressure-sensitive adhesive layer (X)13 is provided on the side of the amorphous film 10 prepared in advance, and the protective film (2)12 of the laminate (P)101 is laminated on the exposed surface of the pressure-sensitive adhesive layer (X)13, and bonded using a laminator or the like.

Further, after the single body of the protective film (2)12 and the amorphous film 10 are laminated via the adhesive layer (X)13 by the above-described method (bonding, co-extrusion molding) or the like, the protective film (1)11 may be formed on the surface of the protective film (2)12 opposite to the amorphous film 10.

The functional film is preferably a laminate in which an amorphous film is laminated directly or via an adhesive layer (X) on the side of the protective film laminate (P) on which the protective film (1) and the protective film (2) are laminated, as the structure of the functional film. That is, the functional film is preferably a functional film in which a protective film (1), a protective film (2), and an amorphous film are directly laminated in this order, or a functional film in which a protective film (1), a protective film (2), an adhesive layer (X), and an amorphous film are directly laminated in this order.

The thickness of the functional film is preferably 10 to 400 μm, more preferably 20 to 300 μm, still more preferably 40 to 200 μm, and still more preferably 50 to 150 μm.

The thickness of the functional film can be measured, for example, by the method described in the examples described below. Alternatively, the calculation may be performed in the form of the total thickness of each layer described later.

The functional film has a curl amount of preferably 10mm or less, more preferably 8mm or less, further preferably 5mm or less, and further preferably 3mm or less, as measured by the method described in examples described later.

Hereinafter, each member constituting the functional film will be described in further detail.

< protective film laminate (P) >)

The protective film laminate (P) is a laminate used mainly for protecting an amorphous film, and is a laminate obtained by laminating protective films (1) and (2). For example, in the case of using as a separate protective film, even when a protective film that does not exhibit the above-described excellent effects of the present invention is used as the protective film (1) or (2), the above-described excellent effects of the present invention can be exhibited by using in the form of a laminate (P). Therefore, as the laminate (P) used in the present invention, a laminate obtained by laminating a general-purpose protective film used in the past can be used, and this embodiment is also preferable from the viewpoint of the availability of raw material resins or films and the economy in terms of cost.

(protective films (1) and (2))

As described above, the functional film is a laminate in which an amorphous film is laminated on the protective film (2) side of the laminate (P). Therefore, the protective film (2) is a protective film laminated on the amorphous film side in the laminate (P). The protective film (1) is a protective film laminated on the side of the laminate (P) opposite to the amorphous film with respect to the protective film (2).

The protective films (1) and (2) are not particularly limited as long as they are films for protecting an amorphous film described later. Among these, the protective films (1) and (2) are preferably protective films having different physical properties (for example, characteristics such as elastic modulus described later) from each other, and more preferably protective films formed of different materials from each other, from the viewpoint of more easily obtaining the excellent effects of the present invention.

At least one of the protective films (1) and (2) may be a laminate of a base film and an adhesive layer (Y) independently of each other. Wherein, when at least one of the protective film (1) and the protective film (2) is a laminate composed of a base film and a pressure-sensitive adhesive layer (Y), the base film serves as the outermost layer of the laminate (P). In this case, the laminate (P) is preferably a laminate in which the protective films (1) and (2) are laminated with each other by at least 1 kind of adhesive layer (Y), and more preferably a laminate in which the protective films (1) and (2) are laminated with each other by 1 kind of adhesive layer (Y).

Here, the term "pressure-sensitive adhesive layer" in the present specification includes not only a layer formed of a pressure-sensitive adhesive but also a layer formed of an adhesive, and is understood to have at least 1 characteristic of adhesiveness and adhesiveness.

The "outermost layer of the laminate (P)" is a layer on the surface side opposite to the protective film (2) if it is on the protective film (1) side, and a layer on the surface side in contact with the amorphous film if it is on the protective film (2) side.

As the protective films (1) and (2), the protective films (1) and (2) having a glass transition temperature (Tg) lower than that of an amorphous film described later can be used independently of each other.

The glass transition temperature (Tg) of the protective films (1) and (2) satisfying these conditions is preferably lower than 140 ℃, more preferably lower than 130 ℃, still more preferably 100 ℃ or lower, and yet more preferably 50 ℃ or lower, and is preferably-150 ℃ or higher, more preferably-100 ℃ or higher, still more preferably-50 ℃ or higher, and still more preferably-30 ℃ or higher, independently of each other.

In addition, as the protective film (1), the protective film (1) having a glass transition temperature (Tg) lower than that of the protective film (2) can be used.

The glass transition temperature (Tg) of the protective film (1) satisfying this condition is preferably 100 ℃ or lower, more preferably 80 ℃ or lower, further preferably 50 ℃ or lower, further preferably 30 ℃ or lower, and further preferably 10 ℃ or lower, and is preferably-150 ℃ or higher, more preferably-100 ℃ or higher, further preferably-50 ℃ or higher, and further preferably-30 ℃ or higher.

The glass transition temperature (Tg) of the protective film (2) satisfying this condition is preferably less than 140 ℃, more preferably less than 130 ℃, still more preferably 100 ℃ or less, and yet more preferably 80 ℃ or less, and is preferably-100 ℃ or more, more preferably-50 ℃ or more, still more preferably-30 ℃ or more, still more preferably more than 10 ℃, and yet more preferably more than 30 ℃.

As the protective film (2), a protective film (2) having a glass transition temperature (Tg) equal to or higher than that of an amorphous film described later can be used.

The glass transition temperature (Tg) of the protective film (2) satisfying this condition is preferably 140 ℃ or higher, more preferably 160 ℃ or higher, and still more preferably 180 ℃ or higher. The upper limit of the glass transition temperature (Tg) of the protective film (2) is not particularly limited, but is preferably 400 ℃, more preferably 350 ℃, and still more preferably 300 ℃.

The values of the glass transition temperatures (Tg) of the protective films (1) and (2) can be measured, for example, by the same method as the method for measuring the glass transition temperature (Tg) of the amorphous film described later.

In the case where at least 1 of the protective films (1) and (2) is a laminate of a base film and a pressure-sensitive adhesive layer (Y), the value of the glass transition temperature (Tg) of each of the protective films (1) and (2) is independently the value of the glass transition temperature (Tg) of the base film. That is, in this case, the values of the glass transition temperatures (Tg) of the base films of the protective films (1) and (2) are regarded as the values of the glass transition temperatures (Tg) of the protective films (1) and (2), respectively.

When the functional film is used in a high-temperature environment or when the functional film is used in a room-temperature environment after being exposed to a high-temperature environment, the protective films (1) and (2) preferably have a lower elastic modulus than the protective film (2) when the protective films (1) and (2) have different physical properties (for example, characteristics such as an elastic modulus described later) from the viewpoint of further suppressing the occurrence of curling.

Specifically, it is more preferable that the tensile storage modulus E ' at 23 ℃ of the protective film (1) is lower than the tensile storage modulus E ' at 23 ℃ of the protective film (2), and it is further preferable that the tensile storage modulus E ' at 23 ℃ of the protective film (1) is 1.0X 10⁷Pa is not less than 3.0X 10⁹Pa and a tensile storage modulus E' of the protective film (2) at 23 ℃ of 3.0X 10⁹Pa or more and 1.0X 10¹¹Pa or less.

The tensile storage modulus E' of the protective film (1) at 23 ℃ is preferably 1.0X 10⁷Pa or more, more preferably 1.0X 10⁸Pa or more, more preferably 5.0X 10⁸Pa or more, and preferably less than 3.0X 10⁹Pa, more preferably 2.0X 10⁹Pa or less, more preferably 1.0X 10⁹Pa or less.

The tensile storage modulus E' of the protective film (2) at 23 ℃ is preferably 3.0X 10⁹Pa or more, more preferably 4.0X 10⁹Pa or more, more preferably 4.5X 10⁹Pa or more, and preferably 1.0X 10¹¹Pa or less, more preferably 1.0X 10¹⁰Pa is atLower, more preferably 8.0X 10⁹Pa or less.

In the case where at least 1 of the protective films (1) and (2) is a laminate of a base film and a pressure-sensitive adhesive layer (Y), the values of the elastic moduli of the protective films (1) and (2) are the values of the elastic modulus of the base film, respectively and independently. That is, in this case, the values of the elastic modulus of the base films of the protective films (1) and (2) are regarded as the values of the elastic modulus of the protective films (1) and (2).

As the protective films (1) and (2), for example, a resin film for protecting an amorphous film used in an optical device can be preferably used independently of each other. Examples of such a film include: a polyolefin protective film, a polyester protective film, a polyimide protective film, a polyamide protective film, a polysulfone protective film, and the like, and more preferably a polyolefin protective film or a polyester protective film.

The laminate (P) is preferably configured such that the protective film (1) is a polyolefin protective film or the protective film (2) is a polyester protective film, and more preferably such that the protective film (1) is a polyolefin protective film and the protective film (2) is a polyester protective film.

As described later, the polyolefin protective film is preferably a polypropylene protective film, and the polyester protective film is preferably a polyethylene terephthalate film. Therefore, as the structure of the laminate (P), it is more preferable that the protective film (1) is a polypropylene protective film or the protective film (2) is a polyethylene terephthalate protective film, and it is further preferable that the protective film (1) is a polypropylene protective film and the protective film (2) is a polyethylene terephthalate protective film.

The polyolefin protective film may be a film in which 50 mass% or more of polyolefin is used in 100 mass% of the raw material resin of the protective film, and in the case where the protective film is composed of a base film and a pressure-sensitive adhesive layer (Y), the polyolefin protective film may be a film in which 50 mass% or more of polyolefin is used in 100 mass% of the raw material resin of the base film. The content of the polyolefin is preferably 80% by mass or more, more preferably 90% by mass or more, further preferably 95% by mass or more, further preferably 98% by mass or more, and further preferably 100% by mass or less, in 100% by mass of the raw resin.

The polyolefin is a resin obtained by polymerizing 1 or 2 or more kinds of olefin monomers, and the olefin monomers are preferably 1 or more kinds selected from ethylene and α -olefins having 3 to 8 carbon atoms, more preferably 1 or more kinds selected from ethylene, propylene, 1-butene, isobutylene, 1-pentene, 1-hexene, 1-octene, and 4-methyl-1-pentene, and the polyolefin is preferably a copolymer of propylene and 1 or more kinds selected from ethylene, 1-butene, isobutylene, 1-pentene, 1-hexene, 1-octene, and 4-methyl-1-pentene, or a propylene homopolymer.

Among these, a polyethylene-based protective film, a polypropylene-based protective film, a poly 4-methylpentene-1-based protective film, and the like are more preferable, and a polypropylene-based protective film is preferable from the viewpoint of more easily obtaining the excellent effects of the present invention and from the viewpoint of general versatility such as ease of obtaining and economy.

The polypropylene-based protective film is a film containing at least 1 of 50 mass% or more of a polypropylene-based copolymer (hereinafter, also referred to as "propylene copolymer", for example, ethylene-propylene copolymer, α -copolymer of olefin and propylene, α -copolymer of ethylene and propylene, and the like) obtained by polymerizing propylene as the olefin-based monomer, preferably 50 mass% or more, preferably 80 mass% or more, more preferably 90 mass% or more, further preferably 95 mass% or more, and preferably less than 100 mass% of propylene, and a propylene homopolymer (homopolypropylene) in 100 mass% of a raw material resin forming the protective film (in the case where the protective film is composed of a base film and a pressure-sensitive adhesive layer (Y), the content of the propylene copolymer and the propylene homopolymer is preferably 80 mass% or more, more preferably 90 mass% or more, further preferably 95 mass% or more, further preferably 98 mass% or more, and preferably 100 mass% or less of the raw material resin).

The polyethylene protective film and the poly 4-methyl-1-pentene protective film have the same meaning as described above, except that "propylene" is changed to "ethylene" or "4-methyl-1-pentene" in the description of the polypropylene protective film.

The polyolefin-based protective film may be an unstretched film, a uniaxially stretched film, or a biaxially stretched film.

In the present specification, the "unstretched film" refers to a film other than a film obtained by intentionally stretching in a specific direction in a film production process. For example, a film other than a film obtained by intentionally stretching a raw material roll of an unstretched film using a transverse stretching machine such as a longitudinal stretching machine and/or a tenter is used. One example of the unstretched film is a CPP film (Cast Polypropylene Films). As one embodiment of the stretched film, for example, OPP film (ordered Polypropylene Films) can be given. In a continuous manufacturing process (for example, a process using a casting device, a winding device, a slitting device, or the like) using a Roll-to-Roll (Roll to Roll) manufacturing device or the like other than the longitudinal stretching machine, the case where the film is stretched by a stress applied thereto so as not to be resisted in the traveling direction only for holding the film is not limited thereto, and may be regarded as an "unstretched film".

The polyester-based protective film may be a film using 50 mass% or more of polyester in 100 mass% of the raw material resin of the protective film, and when the protective film is composed of a base film and a pressure-sensitive adhesive layer (Y), the polyester-based protective film may be a film using 50 mass% or more of polyester in 100 mass% of the raw material resin of the base film. The content of the polyester is preferably 80% by mass or more, more preferably 90% by mass or more, further preferably 95% by mass or more, further preferably 98% by mass or more, and further preferably 100% by mass or less, in 100% by mass of the raw material resin.

Examples of the polyester-based protective film include: a polyethylene terephthalate (PET) protective film, a polybutylene terephthalate (PBT) protective film, a polyethylene naphthalate (PEN) protective film, a polyarylate protective film, and the like, and a polyethylene terephthalate (PET) protective film is preferable from the viewpoint of versatility.

Here, the PET-based protective film is a film containing 50 mass% or more of PET in 100 mass% of the raw material resin forming the protective film (in the case where the protective film is composed of a base film and a pressure-sensitive adhesive layer (Y), the raw material resin of the base film is 100 mass%). The content is preferably 80% by mass or more, more preferably 90% by mass or more, further preferably 95% by mass or more, further preferably 98% by mass or more, and further preferably 100% by mass or less, of 100% by mass of the raw material resin.

The other polyester-based protective films have the same meaning as described above except that "PET" is changed to "PBT", "PEN", or "polyarylate" in the description of the PET-based protective film.

The polyester protective film may be a uniaxially stretched film or a biaxially stretched film.

The polyimide-based protective film may be a film in which 50 mass% or more of the polyimide-based resin is used for 100 mass% of the raw material resin of the protective film, and when the protective film is composed of the base film and the adhesive layer (Y), 50 mass% or more of the polyimide-based resin is used for 100 mass% of the raw material resin of the base film. The content of the polyimide-based resin is preferably 80% by mass or more, more preferably 90% by mass or more, further preferably 95% by mass or more, further preferably 98% by mass or more, and further preferably 100% by mass or less, in 100% by mass of the raw material resin.

Examples of the polyimide-based protective film include: polyimide protective films, polyetherimide protective films, polyamide imide protective films, and the like are preferably polyimide protective films from the viewpoint of heat resistance and dimensional stability.

In the description of the PET-based protective film, the various polyimide-based protective films have the same meaning except that "PET" is changed to "polyimide" and "PET" is changed to "polyetherimide" or "polyamideimide", respectively.

The polyamide-based protective film may be a film in which 50 mass% or more of the polyamide-based resin is used for 100 mass% of the raw material resin of the protective film, and when the protective film is composed of a base film and a pressure-sensitive adhesive layer (Y), 50 mass% or more of the polyamide-based resin is used for 100 mass% of the raw material resin of the base film. The content of the polyamide-based resin is preferably 80% by mass or more, more preferably 90% by mass or more, further preferably 95% by mass or more, further preferably 98% by mass or more, and further preferably 100% by mass or less, in 100% by mass of the raw material resin.

Examples of the polyamide-based protective film include: aliphatic polyamide protective films, aromatic polyamide protective films, and the like.

The various polyamide-based protective films have the same meaning as described above, except that "PET" is changed to "aliphatic polyamide" or "aromatic polyamide" in the description of the PET-based protective film.

Examples of the aliphatic polyamide include: nylon 6, nylon 66, nylon copolymers, and the like.

Further, as the aromatic polyamide, there can be mentioned: examples of the aromatic polyamide include wholly aromatic polyamides such as para-aramid and meta-aramid, and semi-aromatic polyamides obtained by polymerizing monomers used as raw material monomers of aliphatic polyamides with monomers used as raw material monomers of wholly aromatic polyamides.

The polysulfone-based protective film may be a film in which 50 mass% or more of the polysulfone-based resin is used for 100 mass% of the raw material resin of the protective film, and may be a film in which 50 mass% or more of the polysulfone-based resin is used for 100 mass% of the raw material resin of the base film when the protective film is composed of the base film and the adhesive layer (Y). The content of the polysulfone-based resin in 100% by mass of the raw material resin is preferably 80% by mass or more, more preferably 90% by mass or more, further preferably 95% by mass or more, further preferably 98% by mass or more, and further preferably 100% by mass or less.

Examples of the polysulfone-based protective film include: polysulfone protective films, polyethersulfone protective films, and the like.

Note that, in the above description of the PET-based protective film, the terms "PET" and "PET" are used in the same manner, except that "polysulfone" and "polyethersulfone" are used, respectively.

In addition, from the viewpoint of suppressing blocking of the functional film, the protective film (1) is preferably a protective film other than the amorphous protective film, and from the viewpoint of suppressing breakage of the protective film itself, the protective films (1) and (2) are more preferably protective films other than the amorphous protective film. The amorphous protective film is a protective film formed of an amorphous resin.

Here, the amorphous resin means a resin having a crystallinity of less than 25% as measured by X-ray diffraction (XRD). On the other hand, a crystalline resin means a resin having a crystallinity of 25% or more.

{ substrate film }

As described above, in the case where at least one of the protective film (1) and the protective film (2) is a laminate composed of a base film and the adhesive layer (Y), the film that can be used as the base film and the preferred embodiments thereof have been described in the columns of the protective films (1) and (2) as described above, and thus detailed description thereof is omitted.

{ adhesive layer (Y) }

At least one of the adhesive and the binder constituting the adhesive layer (Y) may be appropriately selected depending on the use of the functional film. The pressure-sensitive adhesive layer (Y) may be appropriately selected from layers having removability, permanent adhesiveness, or permanent adhesiveness depending on the application. As described above, the pressure-sensitive adhesive layer (Y) is present as an inner layer of the laminate (P) and can be used for laminating the protective films (1) and (2), and therefore preferably has removability, permanent adhesiveness, or permanent adhesiveness. The pressure-sensitive adhesive layer (Y) may have permanent adhesiveness in the case of use in which the protective film (1) is not required to be peeled from the protective film (2).

Examples of the binder include: acrylic pressure-sensitive adhesives, urethane pressure-sensitive adhesives, silicone pressure-sensitive adhesives, rubber pressure-sensitive adhesives, polyester pressure-sensitive adhesives, and curable pressure-sensitive adhesives that are cured by energy rays such as ultraviolet rays. Among these, an acrylic adhesive, a rubber adhesive, or a silicone adhesive is preferable.

These binders may be used alone, or in combination of 2 or more.

Examples of the adhesive include: an active energy ray-curable adhesive and a thermosetting adhesive.

The active energy ray-curable adhesive has a property of being cured by irradiation with an active energy ray such as ultraviolet ray or electron beam. The active energy ray-curable adhesive is preferably a solvent-free adhesive containing no organic solvent. Adhesives utilizing a photo radical polymerization reaction, such as (meth) acrylate adhesives, olefin/thiol adhesives, epoxy adhesives, oxetane adhesives, epoxy/oxetane adhesives, and unsaturated polyester adhesives; adhesives utilizing photo cation polymerization such as epoxy, vinyl ether and oxetane; and so on.

The thermosetting adhesive has a property of being cured by heating. The thermosetting adhesive is preferably a solvent-free adhesive containing no organic solvent. The thermosetting adhesive includes adhesives that cure at room temperature or higher, and examples thereof include: epoxy adhesives, polyurethane adhesives, (meth) acrylate adhesives, olefin/thiol adhesives, silicone adhesives, polyester adhesives, unsaturated polyester adhesives, cyanoacrylate adhesives, nylon adhesives, modified olefin adhesives, and the like.

Examples of the other adhesive include aqueous adhesives using a polyvinyl alcohol resin aqueous solution, an aqueous two-component urethane emulsion adhesive, and the like. Among these, aqueous solutions of polyvinyl alcohol resins are preferred. Examples of the polyvinyl alcohol resin include: a vinyl alcohol homopolymer obtained by saponifying polyvinyl acetate as a homopolymer of vinyl acetate; vinyl alcohol copolymers obtained by saponification of copolymers of vinyl acetate and other monomers copolymerizable with vinyl acetate; a modified polyvinyl alcohol polymer obtained by partially modifying hydroxyl groups of the vinyl alcohol homopolymer or the vinyl alcohol copolymer; and so on. The aqueous adhesive may contain a polyaldehyde, a water-soluble epoxy compound, a melamine compound, a zirconium oxide compound, a zinc compound, or the like as an additive.

These adhesives may be used alone or in combination of 2 or more.

Examples of the method for producing the laminate (P) include: a method in which either or both of the protective films (1) and (2) are used as a protective film composed of a base film and an adhesive layer (Y), and the protective films (1) and (2) are bonded to each other to obtain a laminate (P). When the protective film (1) and the protective film (2) formed only of the base film are bonded to each other, an adhesive layer may be formed on the surface side of either or both of the base films, and this adhesive layer may be regarded as the adhesive layer (Y) included in the protective film (1) or (2). If necessary, a new pressure-sensitive adhesive layer (Y) may be formed in addition to the pressure-sensitive adhesive layer (Y) included in the protective film, and the protective films (1) and (2) may be bonded to each other to obtain a laminate (P). That is, the pressure-sensitive adhesive layer present as the inner layer of the laminate (P) can be regarded as the pressure-sensitive adhesive layer (Y) included in the protective film (1) or (2).

Examples of the method include a method in which the resin forming the protective film (1) and the resin forming the protective film (2) are co-extruded and directly molded into the laminate (P).

The thickness of the protective film (1) is preferably 1 μm or more, more preferably 3 μm or more, further preferably 10 μm or more, further preferably 30 μm or more, and further preferably 35 μm or more, from the viewpoint of easily suppressing curling of the obtained functional film. In addition, when the obtained functional film is wound up, or when the laminate (P) is peeled from the functional film and used, the thickness of the protective film (1) is preferably 200 μm or less, more preferably 150 μm or less, further preferably 100 μm or less, further preferably 80 μm or less, and further more preferably 60 μm or less, from the viewpoint of the handling properties and the economical efficiency of the functional film in the subsequent step.

In addition, the thickness of the protective film (1) is preferably 0.3 to 1.5 times, more preferably 0.4 to 1.5 times, even more preferably 0.4 to 1.3 times, even more preferably 0.4 to 1.2 times, even more preferably 0.4 to 1.0 times, and even more preferably 0.4 to 0.8 times the thickness of an amorphous film described later, from the viewpoint of easily suppressing the curling of the resulting functional film.

In the case where the protective film (1) is a laminate composed of the base film and the pressure-sensitive adhesive layer (Y), the thickness of the base film is preferably 1 μm or more, more preferably 2 μm or more, still more preferably 10 μm or more, still more preferably 25 μm or more, and still more preferably 30 μm or more, from the viewpoint of easily suppressing curling of the resulting functional film. In addition, when the obtained functional film is wound up, or when the laminate (P) is peeled from the functional film and used, the thickness of the base film is preferably 150 μm or less, more preferably 100 μm or less, further preferably 80 μm or less, further preferably 60 μm or less, and further more preferably 50 μm or less, from the viewpoint of the handling property and the economical efficiency of the functional film in the subsequent step.

The thickness of the adhesive layer (Y) is preferably 1 to 100 μm, more preferably 2 to 50 μm, still more preferably 3 to 30 μm, and still more preferably 5 to 20 μm.

In the case where the protective film (1) is a laminate composed of the base film and the pressure-sensitive adhesive layer (Y), the thickness of the base film is preferably 0.2 to 1.5 times, more preferably 0.3 to 1.3 times, further preferably 0.3 to 1.2 times, and further preferably 0.3 to 1.0 times the thickness of an amorphous film described later, from the viewpoint of easily suppressing curling of the resulting functional film.

The thickness of the protective film (2) is preferably 1 μm or more, more preferably 3 μm or more, still more preferably 10 μm or more, still more preferably 20 μm or more, and still more preferably 25 μm or more, from the viewpoint of easily suppressing curling of the obtained functional film. In addition, when the obtained functional film is wound up, or when the laminate (P) is peeled from the functional film and used, the thickness of the protective film (2) is preferably 200 μm or less, more preferably 150 μm or less, further preferably 100 μm or less, further preferably 80 μm or less, further preferably 60 μm or less, further preferably 50 μm or less, and further preferably 40 μm or less, from the viewpoint of the handling properties and the economical efficiency of the functional film in the subsequent step.

The thickness of the protective film (2) is preferably 0.2 to 1.5 times, more preferably 0.3 to 1.3 times, even more preferably 0.3 to 1.2 times, even more preferably 0.3 to 1.0 times, and even more preferably 0.3 to 0.5 times the thickness of an amorphous film described later, from the viewpoint of easily suppressing the curling of the resulting functional film.

In the case where the protective film (2) is a laminate composed of the base film and the pressure-sensitive adhesive layer (Y), the thickness of the base film is preferably 1 μm or more, more preferably 2 μm or more, still more preferably 10 μm or more, still more preferably 20 μm or more, and still more preferably 25 μm or more, from the viewpoint of easily suppressing curling of the resulting functional film. In addition, when the obtained functional film is wound up, or when the laminate (P) is peeled from the functional film and used, the thickness of the base film is preferably 150 μm or less, more preferably 100 μm or less, further preferably 80 μm or less, further preferably 60 μm or less, further preferably 50 μm or less, and further more preferably 40 μm or less, from the viewpoint of the handling property and the economical efficiency of the functional film in the subsequent step.

In the case where the protective film (2) is a laminate composed of the base film and the pressure-sensitive adhesive layer (Y), the thickness of the base film is preferably 0.2 to 1.5 times, more preferably 0.3 to 1.3 times, even more preferably 0.3 to 1.2 times, even more preferably 0.3 to 1.0 times, and even more preferably 0.3 to 0.5 times the thickness of the amorphous film described later, from the viewpoint of easily suppressing curling of the resulting functional film.

Further, by using the laminate (P), the thickness of each layer of the protective films (1) and (2) can be appropriately adjusted independently. This facilitates adjustment and suppression of the amount of curling of the functional film including the laminate (P). From such a viewpoint, the ratio [ thickness (t 1)/thickness (t2) ] of the thickness of the protective film (1) to the thickness of the protective film (2) is preferably 0.5 to 1.5, more preferably 0.7 to 1.3, and further preferably 0.7 to 1.2.

The thickness of the protective film (1), the thickness of the protective film (2), the thickness of the base film, and the thickness of the pressure-sensitive adhesive layer (Y) can be measured, for example, by the methods described in the examples described below.

The thickness of the laminate (P) is preferably 2 to 300 μm, more preferably 10 to 250 μm, still more preferably 20 to 200 μm, yet more preferably 30 to 150 μm, and yet more preferably 40 to 100 μm.

The thickness of the laminate (P) can be measured, for example, by the method described in the examples described below. Alternatively, the total thickness of the protective films (1) and (2) described later may be calculated.

In addition, the thickness of the laminate (P) is preferably 0.5 to 3.0 times, more preferably 0.6 to 2.4 times, even more preferably 0.7 to 2.0 times, and even more preferably 0.7 to 1.5 times the thickness of the amorphous film described later, from the viewpoint of easily suppressing the curling of the obtained functional film.

If necessary, at least one of the surfaces of the protective films (1) and (2) may be subjected to surface treatment such as sputtering, corona discharge, etching treatment such as flame treatment, ultraviolet irradiation, electron beam irradiation, chemical conversion, or oxidation, or undercoating treatment.

< amorphous film >

The amorphous film is a film formed of an amorphous resin, and is preferably at least 1 type selected from cycloolefin-based films and polycarbonate-based films from the viewpoint of excellent transparency and dimensional stability, and is more preferably a cycloolefin-based film from the viewpoint of low water absorption and excellent heat resistance.

The cycloolefin film is formed of a cycloolefin resin. The cycloolefin resin is a resin obtained by polymerizing a cycloolefin, which is an alicyclic olefin, as a monomer, and has a structural unit derived from the cycloolefin as a repeating unit in a molecule.

Examples of the cycloolefin include norbornene and a substitute thereof (hereinafter, these are collectively referred to as "norbornene-based monomer"). Norbornene is a compound in which the 1 carbon-carbon bond in norbornane is a double bond and is named bicyclo [2,2,1] hept-2-ene according to the IUPAC nomenclature. Examples of the substituent of norbornene include: 3-substituted compounds, 4-substituted compounds and 4, 5-disubstituted compounds each having a 1, 2-position double bond position of norbornene and substituted with a methyl group, an ethyl group, a butyl group, a phenyl group or the like, and 5-ethylidene-2-norbornene.

In addition, polycyclic cyclic olefins such as dicyclopentadiene, dihydrodicyclopentadiene, methyldicyclopentadiene, dimethyldicyclopentadiene, tetracyclododecene, methyltetracyclododecene, dimethylcyclotetradecene, tricyclopentadiene, tetracyclopentadiene, and dimethyloctahydronaphthalene; and monocyclic cyclic olefins such as cyclobutene, cyclopentene, cyclooctene, cyclooctadiene, cyclooctatriene, and cyclododecatriene as monomers constituting the cycloolefin resin.

The cycloolefin-based resin may have a norbornane ring or may not have a norbornane ring in its structural unit. Examples of the norbornene-based monomer that forms the cycloolefin-based resin having no norbornane ring in the structural unit include monomers that form a 5-membered ring by ring opening. Examples of the monomer which becomes a 5-membered ring by the ring opening include: norbornene, dicyclopentadiene, 1-methylnorbornene, 4-phenylnorbornene and the like. Here, for example, a method for producing a resin having a 5-membered ring structure by ring-opening norbornene includes ring-opening metathesis polymerization using a Grubbs (Grubbs) catalyst or the like. As described above, norbornene has a structure having a double bond in a norbornane ring, and for example, when norbornene is addition-polymerized by a metallocene catalyst, a cycloolefin resin having a norbornane ring in its structural unit can be synthesized.

More specific examples of the cycloolefin resin include ring-opened polymers of norbornene monomers, ring-opened copolymers of norbornene monomers and other monomers, modified polymers obtained by adding at least 1 of maleic acid and cyclopentadiene to the above-mentioned polymers, and polymers or copolymers obtained by hydrogenating these polymers, addition polymers of norbornene monomers, addition copolymers of norbornene monomers and other monomers, and other monomers used in the preparation of copolymers, for example, α -olefins such as ethylene and propylene, cycloolefins, unconjugated dienes, and the like, and the cycloolefin resin may be a copolymer obtained by using 1 or 2 or more of norbornene monomers and other alicyclic olefins.

When the cycloolefin resin is a copolymer, the arrangement state of the molecules is not particularly limited, and the cycloolefin resin may be a random copolymer, a block copolymer, or a graft copolymer.

The cycloolefin-based resin can be obtained as a commercially available product, and when the resins are all represented by trade names, examples thereof include: "ZEONEX" and "ZEONOR" (both registered trademarks) sold by kushou corporation of japan; "ARTON (registered trademark)" sold by JSR corporation; "TOPAS (registered trademark)" sold by Polyplastics corporation; "APEL (registered trademark)" sold by mitsui chemical corporation; and so on.

Further, commercially available products can be obtained from films of these cycloolefin resins and stretched films thereof, and when they are both expressed by trade names, for example: "ZEONORFILM (registered trademark)" sold by ruing corporation of japan; "F FILM" sold by GUNZE corporation; "ARTON (registered trademark) FILM" sold by JSR corporation; "ESUSINA (エスシーナ) (registered trademark)" sold by Water chemical industries, Ltd.

The cycloolefin resin can be formed into a film by a solution casting method, a melt extrusion method, or the like. When the film is formed from 2 or more kinds of mixed resins, the film forming method is not particularly limited, and for example: a method of producing a film by a casting method using a homogeneous solution obtained by stirring and mixing a resin component and a solvent at a given ratio, a method of producing a film by a melt extrusion method by melt-mixing a resin component at a given ratio, and the like.

The polycarbonate-based film is a film made of a polycarbonate-based resin.

The polycarbonate-series resin is a resin having a carbonate group in the main chain. The polycarbonate-series resin is not particularly limited, and a known resin can be used. Examples of the polycarbonate include: aromatic polycarbonate, aliphatic polycarbonate, aromatic-aliphatic polycarbonate, and the like. Among them, from the viewpoint of excellent heat resistance, mechanical strength, transparency, and the like, 1 or more selected from aromatic-aliphatic polycarbonates and aromatic polycarbonates are preferable, and aromatic polycarbonates are more preferable.

The aromatic polycarbonate can be obtained by the following method: a method of reacting an aromatic diol with a carbonate precursor by an interfacial polycondensation method or a melt transesterification method, a method of polymerizing a carbonate prepolymer by a solid-phase transesterification method, or a method of polymerizing by a ring-opening polymerization method of a cyclic carbonate compound.

Examples of the aromatic polycarbonate include polycarbonates using bisphenols. Examples of the polycarbonate using a bisphenol include: bisphenol A polycarbonate, branched bisphenol A polycarbonate, foamed polycarbonate, copolycarbonate, block copolycarbonate, polyester carbonate, polyphosphonate carbonate, diethylene glycol bisallylcarbonate (CR-39), and the like. The polycarbonate-based resin also includes a resin composition containing a polycarbonate blended with other components such as a bisphenol a polycarbonate blend, a polyester blend, an ABS blend, a polyolefin blend, and a styrene-maleic anhydride copolymer blend.

The polycarbonate-series resin may be obtained as a commercially available product, and when the polycarbonate-series resin is represented by the trade name, examples thereof include: "Panlite (registered trademark)" sold by Diite corporation; "Iupilon (registered trademark)" sold by mitsubishi gas chemical corporation; and so on.

Further, commercially available products can be obtained from the films of the polycarbonate-based resins and stretched films thereof, and when they are both referred to by the trade names, examples thereof include: "Pureace (registered trademark)" sold by Imperial corporation; "Ifpilon (registered trademark) SHEET" sold by Mitsubishi gas chemical corporation; and so on.

The amorphous film may contain other components such as a stabilizer, a plasticizer, an antioxidant, an antistatic agent, a leveling agent, and an ultraviolet absorber, if necessary.

The surface of the amorphous film may be subjected to surface treatment such as sputtering, corona discharge, flame, ultraviolet irradiation, electron beam irradiation, etching treatment such as chemical conversion and oxidation, and undercoating treatment in advance as required.

The thickness of the amorphous film is preferably 1 to 100 μm, more preferably 10 to 90 μm, still more preferably 10 to 80 μm, yet more preferably 30 to 80 μm, and yet more preferably 45 to 80 μm.

The thickness of the amorphous film can be measured, for example, by the method described in the examples described later.

The glass transition temperature (Tg) of the amorphous resin forming the amorphous film is preferably 130 ℃ or higher, more preferably 140 ℃ or higher, and still more preferably 150 ℃ or higher. The upper limit of the glass transition temperature (Tg) is not particularly limited, but is preferably 250 ℃, more preferably 200 ℃, and still more preferably 180 ℃.

The value of the glass transition temperature (Tg) of the amorphous film can be measured, for example, by the following method.

The amorphous film was cut into a long shape of 5mm in the transverse direction (TD direction) by 15mm in the longitudinal direction (MD direction) to prepare a test piece. Subsequently, tan δ (ratio of loss elastic modulus to storage modulus) of the test piece was measured in a tensile mode at a frequency of 10Hz, a temperature rise rate of 5 ℃/min, and an atmospheric atmosphere at 0 to 350 ℃ using a viscoelasticity measuring apparatus ("DMA Q800" manufactured by TA Instruments). In this temperature range, the temperature at which tan δ exhibits the maximum value is read as the glass transition temperature (Tg) of the amorphous film.

The MD Direction is an abbreviation for Machine Direction, and the MD Direction is a longitudinal Direction in film forming. TD in the TD Direction is an abbreviation for transient Direction, and TD Direction refers to the width Direction during film formation.

< adhesive layer (X) >

The functional film as the laminate is preferably a laminate further having a pressure-sensitive adhesive layer (X) between the amorphous film and the laminate (P).

When the functional film of the present invention has the pressure-sensitive adhesive layer (X), at least 1 of the pressure-sensitive adhesive and the adhesive constituting the pressure-sensitive adhesive layer (X) can be appropriately selected depending on the use of the functional film.

The pressure-sensitive adhesive layer (X) may be a layer having removability, permanent adhesiveness, or permanent adhesiveness, as appropriate depending on the application, and preferably has removability.

Examples of the binder include: acrylic pressure-sensitive adhesives, urethane pressure-sensitive adhesives, silicone pressure-sensitive adhesives, rubber pressure-sensitive adhesives, polyester pressure-sensitive adhesives, and curable pressure-sensitive adhesives that are cured by energy rays such as ultraviolet rays. Among these, an acrylic pressure-sensitive adhesive is preferable, and the acrylic pressure-sensitive adhesive is not particularly limited, and for example, an acrylic pressure-sensitive adhesive containing 50 mass% or more of an acrylic resin polymerized by using 50 mass% or more of an alkyl (meth) acrylate having 4 to 10 carbon atoms in the alkyl group with respect to 100 mass% of the total amount of the raw material monomers, preferably a 2EHA pressure-sensitive adhesive using 2-ethylhexyl acrylate (2EHA) described later, is preferably used in 100 mass% of the total amount of the used resins.

Examples of the alkyl (meth) acrylate having an alkyl group of 4 to 10 carbon atoms include: butyl (meth) acrylate, octyl (meth) acrylate, isooctyl (meth) acrylate, 2-ethylhexyl (meth) acrylate, and the like, alkyl (meth) acrylates having an alkyl group with 6 to 10 carbon atoms are preferred, alkyl (meth) acrylates having an alkyl group with 8 carbon atoms are more preferred, and 2-ethylhexyl acrylate (2EHA) is further preferred.

These binders may be used alone, or in combination of 2 or more.

As the adhesive, the adhesive exemplified in the above-mentioned pressure-sensitive adhesive layer (Y) can be used, and preferred embodiments thereof are also the same. These adhesives may be used alone or in combination of 2 or more.

The thickness of the adhesive layer (X) is not particularly limited, but is preferably 1 to 100. mu.m, more preferably 3 to 50 μm, and still more preferably 5 to 30 μm.

The thickness of the adhesive layer (X) can be measured, for example, by the method described in the examples described below.

< other layer >

The functional film as the laminate may have other layers in addition to the laminate (P), the amorphous film, and the pressure-sensitive adhesive layer (X) in the range where the effects of the present invention are not impaired.

The other layer may be laminated between the laminate (P) and at least 1 layer of the amorphous film and the pressure-sensitive adhesive layer (X), or may be laminated on the opposite side of the amorphous film from the laminate (P), for example. Examples of such other layers include: 1 or 2 or more protective films made of the same or different material as the protective film (1) or (2), an undercoat layer, an adhesive layer other than the adhesive layer (X), a refractive index adjusting layer, an anti-blocking layer, a hard coat layer, a gas barrier layer, and the like.

The above-described functional film is preferably a laminate in which an amorphous film is laminated directly or through an adhesive layer (X) on the side of the protective film (2) of the protective film laminate (P) in which the protective film (1) and the protective film (2) are laminated. That is, the functional film is preferably a functional film in which a protective film (1), a protective film (2), and an amorphous film are directly laminated in this order, or a functional film in which a protective film (1), a protective film (2), an adhesive layer (X), and an amorphous film are directly laminated in this order.

[ protective film laminate for amorphous film ]

The protective film laminate for an amorphous film according to another embodiment of the present invention is a protective film laminate (P) in which a protective film (1) and a protective film (2) are laminated. Here, the protective film laminate (P), the protective film (1), and the protective film (2) as the protective film laminate for an amorphous film, and preferred embodiments thereof are described in the above-mentioned column of the functional film, respectively, and thus detailed description thereof is omitted.

[ use of functional film ]

The functional film according to one embodiment of the present invention is a functional film having the amorphous film described above, and therefore is suitable for use as a functional film used for manufacturing an optical device. For example, when used as a functional film for an optical device, the functional film can be used for manufacturing a member for an optical device by laminating various functional layers such as a transparent conductive film, an optical adjustment layer, and a polarizing plate on the amorphous film side. The amorphous film itself may be used as a retardation film, a substrate such as a liquid crystal cell substrate, or a polarizer protective film, for example. In such a manufacturing process, the laminate (P) functions to protect the amorphous film.

In addition, the functional film of the present invention can suppress curling even when used in a high-temperature environment. Therefore, the functional film is more suitable for use in a process for use at high temperature, for example, in the production of a member used for an optical device. That is, the functional film is more suitable for use as a functional film for an optical device produced by the above process. Examples of the process include: when the amorphous film is used as one member such as a transparent conductive film as described above, the amorphous film is used in a step of bonding the amorphous film to another member using an adhesive such as the above-described thermosetting adhesive; or a transparent conductive film is laminated on the amorphous film, and then subjected to a heating step such as an annealing step for crystallizing the transparent conductive film.

In addition, the functional film according to one embodiment of the present invention can suppress curling even when a load is applied in a high-temperature environment. Therefore, in the production process of an optical member used for an optical device, the functional film is more suitable for use in a process in which a load is applied at a high temperature, such as a Roll-to-Roll (Roll) process. That is, the functional film is more suitable for use as a functional film for an optical device produced by the above process.

In addition, the protective film laminate for an amorphous film according to an embodiment of the present invention can be used as the functional film according to the embodiment of the present invention, and the functional film having the protective film laminate exerts the above-described excellent effects. Therefore, the preferred application of the protective film laminate for an amorphous film according to one embodiment of the present invention is the same as the application in which the functional film described above can be preferably used.

The optical device is not particularly limited as long as the above-mentioned functional film of the present invention is used in the production process of the optical device, and examples thereof include: a Light Emitting Diode (LED); liquid Crystal Displays (LCDs); electroluminescent (EL) devices such as organic electroluminescence (organic EL) devices and inorganic electroluminescence (inorganic EL) devices; plasma Display Panels (PDP); a touch panel; cathode Ray Tubes (CRT); optical devices such as electronic paper and solar cells. Among them, the functional film is preferably EL, and more preferably organic EL.

Examples

The present invention will be described in more detail with reference to examples. However, the present invention is not limited to the following examples.

The characteristics of each amorphous film, each protective film (base film and adhesive layer (Y)), and adhesive layer (X) used in each example and each comparative example, and the obtained functional film were evaluated based on the following methods. The results are shown in table 1.

Thickness of amorphous film, adhesive layer (X), protective film, substrate film, adhesive layer (Y), laminate (P), and hard coat layer

The thickness of each amorphous film and each protective film used in each example and each comparative example was measured using a constant-pressure thickness gauge (type: "PG-02J", in accordance with the standard: JIS K6783:1994, JIS Z1702:1994, JIS Z1709:1995) manufactured by Telock corporation.

The thickness of the base film in each protective film is a measured value of the thickness of the portion of the protective film not coated with the pressure-sensitive adhesive layer (Y). The thickness of the pressure-sensitive adhesive layer (Y) in each protective film is obtained by subtracting the thickness of the base film from the thickness of the portion where both the base film and the pressure-sensitive adhesive layer (Y) are laminated (that is, the thickness of the protective film).

The thickness of the pressure-sensitive adhesive layer (X) after drying was measured by the same method for the thickness of the laminate (P) with the pressure-sensitive adhesive layer (X) obtained in each example and each comparative example, and the thickness of the laminate (P) (total thickness of the protective films (1) and (2)) measured in advance was subtracted.

In addition, as the thickness of the hard coat layer, a value obtained by measuring the thickness of the amorphous film with the hard coat layer obtained in each example and each comparative example by the same method and subtracting the measured value of the amorphous film thickness measured in advance from the obtained measured value was used.

< tensile storage modulus E' >, at 23 ℃ of amorphous film, protective film (1) and protective film (2)

Each of the protective films and each of the amorphous films used in the examples and comparative examples was cut into a long shape of 5mm in the transverse direction (TD direction) × 20mm in the longitudinal direction (MD direction), to prepare test pieces. Then, the tensile storage modulus E 'was measured in a tensile mode at a frequency of 10Hz, a temperature rise rate of 3 ℃/min and a temperature range of 0 ℃ to 200 ℃ by using a dynamic viscoelasticity measuring apparatus (product name "DMA 242E Artemis" manufactured by NETZSCH Japan) to obtain the tensile storage modulus E' at 23 ℃.

< glass transition temperature (Tg) > < amorphous film

The glass transition temperature of the amorphous film used in each example and each comparative example was measured by the method described in the specification.

< evaluation of curling of functional film 1 >

The functional films 1 to 18 produced in the examples and comparative examples were cut into a size of 100mm × 100mm to produce test pieces.

The test piece was heated at 150 ℃ for 60 minutes using an oven "SPHH-202" manufactured by Espec corporation.

After 60 minutes of heating, the test piece was taken out of the oven, cooled naturally, and the temperature of the test piece was confirmed to have been lowered to room temperature (25 ℃ C.), and the test piece was allowed to stand on a horizontal stand. The floating height (height from the table surface) of the test piece at 4 corners (4 vertexes) was measured with a ruler, and the average value of the obtained 4 heights was calculated and used as the curl amount.

The test piece was judged to be good or not for the effect of suppressing the curl of each test piece, with the value of the curl amount being 10mm or less being "good" and the value exceeding 10mm being "bad".

The obtained results are shown in tables 1 and 2 below.

The amount of curling is a positive value when the amorphous film floats and a negative value when the protective film (1) floats.

< evaluation of curling of functional film 2 >

The functional films 1 to 18 produced in the examples and comparative examples were cut into 200mm × 100mm sizes to produce test pieces.

A tensile force of 20N/100mm was applied to one short side of the test piece so as to apply a tensile force in the longitudinal direction of the test piece.

The test piece was heated at 100 ℃ for 5 minutes using an oven "SPHH-202" manufactured by Espec corporation in a state where the tension was applied.

After heating for 5 minutes, the test piece was taken out of the oven, cooled naturally while maintaining the applied tension, and the temperature of the test piece was confirmed to have been lowered to room temperature (25 ℃ C.), and the center portion of the test piece was cut to obtain a 100mm × 100mm test piece. The test piece cut into pieces of 100mm × 100mm was left on a horizontal table. The floating height (height from the table surface) of the test piece at 4 corners (4 vertexes) was measured with a ruler, and the average value of the obtained 4 heights was calculated and used as the curl amount.

The obtained results are shown in tables 1 and 2 below.

[ example 1]

As the protective film (1), an unstretched polypropylene-based protective film (model "EC 7507" manufactured by SUMIRON corporation) was prepared, which was a film formed of a base film and an adhesive layer (Y) formed of an acrylic adhesive, the thickness of the base film was 30 μm, and the thickness of the adhesive layer (Y1) was 7 μm.

As the protective film (2), a polyethylene terephthalate film (model "NW 07T 600E", manufactured by mitsubishi chemical corporation, 25 μm thick) was prepared.

The protective film (1) and the protective film (2) were laminated with the adhesive layer (Y) using a roll Laminator "RSL-380S" manufactured by Japan Office laminators, to produce a laminate (P). Next, a 2 EHA-based adhesive was applied to the protective film (2) side of the laminate (P) so that the thickness of the dried adhesive layer (X) was 7 μm, thereby forming a coating film. The coating film was heated at 100 ℃ for 1 minute to form a pressure-sensitive adhesive layer (X).

As the amorphous Film, a cycloolefin polymer Film (1) (manufactured by Japan ruiweng corporation, Zeonor Film (registered trademark), model "ZF 16-080", thickness 80 μm) was used, and the exposed surface of the pressure-sensitive adhesive layer (X) was bonded to the surface of the amorphous Film by a roll Laminator "RSH-380 SL" manufactured by Japan Office Laminator, to obtain a functional Film 1 as a laminate.

[ example 2]

A functional film 2 was obtained in the same manner as in example 1 except that the amorphous film used in example 1 was changed to a polycarbonate film (model "C110-40" manufactured by Diko K.K., having a thickness of 40 μm).

[ example 3]

A functional Film 3 was obtained in the same manner as in example 1, except that the amorphous Film used in example 1 was changed to a cycloolefin copolymer Film (model "F1 Film" manufactured by GUNZE corporation, thickness 80 μm).

[ example 4]

A functional Film 4 was obtained in the same manner as in example 1, except that the amorphous Film used in example 1 was changed to a cycloolefin polymer Film (Zeonor Film (registered trademark), model "ZF 16-040", thickness 40 μm, manufactured by reilian corporation, and a hard coat layer having a thickness of 1 μm was provided on the surface of the amorphous Film opposite to the surface on which the protective Film laminate was provided.

The hard coat layer was formed by applying an Ultraviolet (UV) -curable acrylate resin composition (product name "OPSTAR (registered trademark) Z7530" manufactured by mithrawa chemical industries, ltd.) using a Mayer bar coater (Mayer bar) and drying the obtained coating film at 70 ℃ for 1 minute. Then, a high pressure mercury lamp (manufactured by Heraeus) was used at an illuminance of 250mW/cm²The quantity of light was 170mJ/cm²The coating film was irradiated with ultraviolet rays at a line speed of 20 m/min to cure the Ultraviolet (UV) -curable acrylate resin composition, thereby forming a hard coat layer having a thickness of 1 μm.

[ example 5]

A functional film 5 was obtained in the same manner as in example 4 except that the protective film (2) used in example 4 was changed to a polyethylene terephthalate film (COSMOSHINE (registered trademark), model "PET 50a 4300", thickness 50 μm, manufactured by toyobo co., ltd.).

[ example 6]

A functional film 6 was obtained in the same manner as in example 4 except that the protective film (1) used in example 4 was changed to a biaxially oriented polypropylene protective film (manufactured by futamuramical corporation, model "150M", a film formed of a base film and an adhesive layer (Y2), the adhesive layer (Y2) being formed of an acrylic adhesive, the base film having a thickness of 30 μ M, and the adhesive layer (Y2) having a thickness of 7 μ M).

[ example 7]

A functional film 7 was obtained in the same manner as in example 1, except that the hard coat layer described in example 4 was provided on the surface of the amorphous film opposite to the surface provided with the protective film laminate in the functional film 1 described in example 1.

[ example 8]

A functional film 8 was obtained in the same manner as in example 2, except that the hard coat layer described in example 4 was provided on the surface of the amorphous film opposite to the surface provided with the protective film laminate in the functional film 2 described in example 2.

[ example 9]

A functional film 9 was obtained in the same manner as in example 4, except that the amorphous film used in example 4 was changed to a cycloolefin copolymer film (model "FXFilm", 40 μm thick, manufactured by GUNZE).

Comparative example 1

A functional film 10 was obtained in the same manner as in example 1, except that the protective film (1) was not used in example 1 and the protective film (2) was a polyethylene terephthalate film (COSMOSHINE (registered trademark), model "PET 50a 4300", thickness 50 μm, manufactured by toyobo co., ltd.).

Comparative example 2

A functional Film 11 was obtained in the same manner as in comparative example 1, except that the amorphous Film used in comparative example 1 was changed to a cycloolefin polymer Film (Zeonor Film (registered trademark), model "ZF 16-040", thickness 40 μm, manufactured by rikino corporation).

Comparative example 3

A functional film 12 was obtained in the same manner as in comparative example 1 except that the amorphous film used in comparative example 1 was changed to a polycarbonate film (model "C110-40" manufactured by Diko K.K., having a thickness of 40 μm).

Comparative example 4

A functional film 13 was obtained in the same manner as in comparative example 1, except that the amorphous film used in comparative example 1 was changed to a cycloolefin copolymer film (model "FXFilm", 40 μm thick, manufactured by GUNZE).

Comparative example 5

A functional film 14 was obtained in the same manner as in comparative example 2, except that the hard coat layer described in example 4 was provided on the surface of the amorphous film opposite to the surface provided with the protective film laminate in the functional film 11 described in comparative example 2.

Comparative example 6

A functional film 15 was obtained in the same manner as in comparative example 5, except that the protective film (2) used in comparative example 5 was changed to a polyethylene terephthalate film (model No. NW07T600E, manufactured by mitsubishi chemical corporation, thickness 25 μm).

Comparative example 7

A functional film 16 was obtained in the same manner as in comparative example 5, except that the protective film (2) used in comparative example 5 was changed to a polyethylene terephthalate film (model "U48" manufactured by Toray, thickness 125 μm).

Comparative example 8

A functional film 17 was obtained in the same manner as in example 4, except that the protective film (2) and the pressure-sensitive adhesive layer (X) were not used in example 4. (that is, the protective film (1) of example 4 and the amorphous film with a hard coat layer were directly laminated.)

Comparative example 9

A functional film 18 was obtained in the same manner as in example 6, except that the protective film (2) and the pressure-sensitive adhesive layer (X) were not used in example 6. (that is, the protective film (1) of example 6 and the amorphous film with a hard coat layer were directly laminated.)

[ Table 1]

*1: the protective film (1) (base material layer/adhesive layer (Y))/protective film (2)/adhesive layer (X)/amorphous film were laminated in this order

*2: CPP: an unstretched polypropylene film; OPP: stretching a polypropylene film; PET: polyethylene terephthalate film

*3: COP: a cycloolefin film; PC: a polycarbonate film; COC: cycloolefin copolymer film

*4: HC: a hard coat layer formed on the surface of the amorphous film opposite to the surface provided with the laminate (P)

*5: evaluation 1: 150 ℃ for 60 minutes (no load condition); evaluation 2: 100 ℃ for 5 minutes (load condition)

[ Table 2]

*3: COP: a cycloolefin film; PC: a polycarbonate film; and (3) CoC: cycloolefin copolymer film

*6: "> 50" indicates a curl amount of more than 50mm

From table 1, it was confirmed that the functional films 1 to 9 of examples 1 to 9 have a small amount of curling and suppressed curling even when exposed to a high-temperature environment. In addition, it was confirmed that the functional films 1 to 9 of examples 1 to 9 have a small amount of curling and suppressed curling even when a load is applied under a high-temperature environment.

On the other hand, as can be seen from table 2, the functional films 10 to 18 of comparative examples 1 to 9 have a large amount of curling when exposed to a high-temperature environment, and it is difficult to suppress curling. In addition, it was confirmed that the functional films 10 to 18 of comparative examples 1 to 9 further increased the amount of curling when a load was applied under a high temperature environment, and it was difficult to suppress curling.

< evaluation of curling of functional film 3 >

The functional films 19 to 22 produced in examples 10 and 11 and comparative examples 10 and 11 described later were cut into a size of 100mm × 100mm to produce test pieces.

The test piece was heated at 150 ℃ for 5 minutes using an oven "SPHH-202" manufactured by Espec corporation.

After heating for 5 minutes, the test piece was taken out of the oven, cooled naturally, and it was confirmed that the temperature of the test piece had been lowered to room temperature (25 ℃ C.), and the test piece was left standing on a horizontal stand. The floating height (height from the table surface) of the test piece at 4 corners (4 vertexes) was measured with a ruler, and the average of the obtained 4 heights was calculated and used as the curl amount.

The obtained results are shown in table 1 below.

[ example 10]

As the protective film (1), a polypropylene-based protective film (model "EC-430" manufactured by SUMIRON corporation, a film formed of a base film and an adhesive layer (Y3), the adhesive layer (Y3) being formed of an acrylic adhesive, the thickness of the base film being 40 μm, and the thickness of the adhesive layer (Y3) being 5 μm) was prepared.

As the protective film (2), a polyethylene terephthalate film (COSMOSHINE (registered trademark), model "PET 38a 4300", thickness 38 μm, manufactured by toyobo co., ltd.) was prepared.

The protective film (1) and the protective film (2) were laminated with an adhesive layer (Y3) using a roll Laminator "RSL-380S" manufactured by Japan Office laminators, to produce a laminate (P). Next, a 2 EHA-based adhesive was applied to the protective film (2) side of the laminate (P) so that the thickness of the dried adhesive layer (X) was 10 μm, thereby forming a coating film. The coating film was heated at 100 ℃ for 1 minute to form a pressure-sensitive adhesive layer (X).

As the amorphous Film, a cycloolefin polymer Film (1) (manufactured by Japan ruiweng corporation, Zeonor Film (registered trademark), model "ZF 16-040", thickness 40 μm) was used, and the exposed surface of the pressure-sensitive adhesive layer (X) was bonded to the surface of the amorphous Film by a roll Laminator "RSH-380 SL" manufactured by Japan Office Laminator, to obtain a functional Film 19 as a laminate.

[ example 11]

A functional film 20 was obtained in the same manner as in example 10, except that the protective film (1) used in example 10 was changed to a polypropylene-based protective film (manufactured by hitachi chemical corporation, model "P-5310", a film formed of a base film and an adhesive layer (Y), the adhesive layer (Y) being formed of an acrylic adhesive, the thickness of the base film being 30 μm, and the thickness of the adhesive layer (Y) being 5 μm).

Comparative example 10

A functional film 21 was obtained in the same manner as in example 10, except that in example 10, the protective film (1) was not used and only the protective film (2) was used.

Comparative example 11

A functional film 22 was obtained in the same manner as in example 10, except that in example 10, the protective film (2) was not used, and only the protective film (1) was used.

[ Table 3]

*7: examples 10 and 11 the protective film (1)/the protective film (2)/the adhesive layer (X)/the amorphous film were laminated in this order

*8: PP: polypropylene; PET: polyethylene terephthalate

*9: the sum of the thicknesses of the base film and the adhesive layer (Y)

*10: COP: cyclic olefins

*11: evaluation 3: 150 ℃ for 5 minutes (no load condition)

As can be seen from table 3, the functional films 19 and 20 of examples 10 and 11 had a small amount of curling and were inhibited from curling even when exposed to a high-temperature environment.

On the other hand, it was confirmed that the functional films 21 and 22 of comparative examples 10 and 11 had a large amount of curling when exposed to a high-temperature environment, and it was difficult to suppress curling.

Industrial applicability

The functional film using the protective film laminate according to one embodiment of the present invention can suppress curling in a high-temperature environment. The functional film is a functional film having an amorphous film, and therefore is suitable as a protective film laminate used for a functional film used for manufacturing an optical device. The protective film laminate is suitably used for a functional film used in a process of manufacturing a member for an optical device, for example, a process used at a high temperature. That is, the film is more suitable as a protective film laminate used for a functional film for an optical device produced through this process. Examples of the process include: as described above, when the amorphous film is used as one member such as a transparent conductive film, the use in the step of bonding the amorphous film to another member using an adhesive such as the above-mentioned thermosetting adhesive; or a transparent conductive film is laminated on the amorphous film, and then subjected to a heating step such as an annealing step for crystallizing the transparent conductive film.

In addition, the functional film using the protective film laminate according to one embodiment of the present invention can suppress curling even when a load is applied at a high temperature. Therefore, in the production process of an optical member used for an optical device, the protective film laminate is more suitable as a protective film laminate for a functional film used in a process in which a load is applied at a high temperature, such as a Roll-to-Roll (Roll) process. That is, the protective film laminate is more suitable for use as a functional film for an optical device produced by the above process.

The functional film according to an embodiment of the present invention is a functional film using the protective film laminate according to an embodiment of the present invention as described above, and thus can be suitably used for various applications described above.

Claims

1. A protective film laminate (P) for an amorphous film is obtained by laminating a protective film (1) and a protective film (2).

2. The protective film laminate for amorphous films according to claim 1, wherein the protective films (1) and (2) are protective films made of different materials.

3. The protective film laminate for amorphous films according to claim 1 or 2, wherein at least one of the protective film (1) and the protective film (2) is composed of a base film and a pressure-sensitive adhesive layer (Y).

4. A protective film laminate for amorphous films according to any one of claims 1 to 3, wherein the tensile storage modulus E 'of the protective film (1) at 23 ℃ is lower than the tensile storage modulus E' of the protective film (2) at 23 ℃.

5. A protective film laminate for amorphous films according to any one of claims 1 to 4, wherein the tensile storage modulus E' of the protective film (1) at 23 ℃ is 1.0 x 10⁷Pa is not less than 3.0X 10⁹Pa, the tensile storage modulus E' of the protective film (2) at 23 ℃ is 3.0X 10⁹Pa or more and 1.0X 10¹¹Pa or less.

6. The protective film laminate for amorphous films according to any one of claims 1 to 5, wherein the protective film (1) is a polyolefin protective film.

7. The protective film laminate for amorphous films according to any one of claims 1 to 6, wherein the protective film (2) is a polyester-based protective film.

8. The protective film laminate for amorphous films according to any one of claims 1 to 7, wherein the protective film (1) is a polyolefin protective film and the protective film (2) is a polyester protective film.

9. A functional film which is a laminate comprising an amorphous film laminated on the protective film (2) side of the protective film laminate for amorphous films according to any one of claims 1 to 8.

10. The functional film according to claim 9, further having an adhesive layer (X) between a protective film laminate (P) and the amorphous film.

11. The functional film according to claim 9 or 10, wherein the thickness of the protective film (1) is 0.3 to 1.5 times the thickness of the amorphous film.

12. The functional film according to any one of claims 9 to 11, wherein the thickness of the protective film laminate (P) is 2 μm or more and 300 μm or less.

13. The functional film according to any one of claims 9 to 12, wherein the amorphous film is 1 or more selected from a cycloolefin film and a polycarbonate film.

14. The functional film according to any one of claims 9 to 13, wherein the thickness of the amorphous film is 1 μm or more and 100 μm or less.

15. The functional film according to any one of claims 9 to 14, which is used for an optical device.