JP2024069059A - Film, laminate, method for producing laminate, card, and passport - Google Patents

Abstract

[Problem] Even when a specific polycarbonate resin is used, peeling between fused films can be prevented without increasing the fusion temperature, and interlayer peeling in a multilayer film can be prevented. [Solution] A film having a resin layer (1) made of a resin composition (1) containing a polycarbonate resin (A) having a structural unit (A1) derived from a dihydroxy compound having a moiety represented by the following formula (1) as part of its structure, and a polycarbonate resin (B) other than the polycarbonate resin (A). [Chemical 1]JPEG2024069059000007.jpg1547 (excluding the case where the moiety represented by formula (1) is a part of -CH2-O-H.) [Selected Figure] None

Description

The present invention relates to a film containing a polycarbonate resin, as well as a laminate, card, and passport that include the film.

In recent years, in order to reduce the burden on the environment, it has been considered to replace some of the resin raw materials from fossil fuel-derived resins with plant-derived resins. The use of plant-derived resins in resin films used in cards and passports has also been considered. For example, Patent Document 1 considers the use of a resin composition whose main component is a polycarbonate resin having structural units derived from isosorbide or its stereoisomers in a card sheet (see Patent Document 1).

When manufacturing cards, passports, etc., it is common to laminate multiple resin films and integrate them by heat pressing. For example, Patent Document 2 discloses a card in which an isosorbite polymer sheet made of an isosorbite polymer having structural units derived from isosorbide is fused to another resin sheet such as a heat-resistant PETG sheet or a heat-resistant PVC sheet. Patent Document 2 also shows that the use of isosorbite polymer reduces the environmental impact and allows it to be heat-fused to other resin sheets at a relatively low temperature.

Patent No. 5822467 Patent No. 6476543

However, when a polycarbonate resin having structural units derived from a specific dihydroxy compound such as isosorbide is used in a resin film, the resin film may not be fused with high adhesive strength to a resin film containing resin components other than polycarbonate resin, such as a PETG sheet or a PVC sheet, and peeling may occur between the fused films.

In addition, the resin film may be made into a multilayer film in order to impart various functions to the resin film itself. However, even when a layer containing a polycarbonate resin having a structural unit derived from the above-mentioned specific dihydroxy compound is made into a multilayer film together with a layer containing a resin component other than the polycarbonate resin, such as PETG, the adhesive strength between the layers in the multilayer film may be insufficient, and interlayer peeling may occur.
Furthermore, in a multilayer film, it is possible to increase the adhesive strength between layers in the multilayer film by adding another resin to a layer containing PETG or the like. However, in such a case, problems may arise, such as the need to increase the fusion temperature when fusing the multilayer film to another film.

The present invention aims to provide a film that can prevent peeling between fused films without increasing the fusion temperature, even when using a polycarbonate resin that has structural units derived from a specific dihydroxy compound such as isosorbite, and can also prevent interlayer peeling in a multilayer film.

After extensive research, the present inventors have found that the above problems can be solved by incorporating a polycarbonate resin (B) other than the polycarbonate resin (A) having a structural unit derived from a specific dihydroxy compound such as isosorbide in at least one resin layer constituting the film, and have completed the present invention as described below. That is, the present invention provides the following [1] to [19].

[1] A film having a resin layer (1) made of a resin composition (1) containing a polycarbonate resin (A) having a structural unit (A1) derived from a dihydroxy compound having a moiety represented by the following formula (1) as a part of its structure, and a polycarbonate resin (B) other than the polycarbonate resin (A).

(However, this does not include the case where the moiety represented by the formula (1) is a part of -CH ₂ -O-H.)
[2] The film according to the above [1], wherein the proportion of the polycarbonate resin (B) is more than 10% by mass and not more than 90% by mass in the resin composition (1).
[3] The film according to the above [1] or [2], wherein the resin composition (1) contains a filler.
[4] The film described in [3] above, wherein the filler is titanium oxide.
[5] The film according to any one of the above [1] to [4], further comprising a resin layer (2) made of a resin composition (2) containing a polyester resin.
[6] The film according to the above [5], wherein the resin composition (2) contains an amorphous polyester.
[7] The film according to the above [5] or [6], wherein the resin composition (2) contains a filler.
[8] The film according to the above [7], wherein the filler in the resin composition (2) is titanium oxide.
[9] The film according to any one of the above [1] to [8], wherein the polycarbonate resin (A) contains 30 mol % or more of the structural unit (A1) in structural units derived from a dihydroxy compound.
[10] The film according to any one of the above [1] to [9], wherein the polycarbonate resin (A) contains 80 mol % or less of the structural unit (A1) in structural units derived from a dihydroxy compound.
[11] The film according to any one of the above [1] to [10], wherein the polycarbonate resin (A) is derived from at least one dihydroxy compound selected from the group consisting of an aliphatic dihydroxy compound and an alicyclic dihydroxy compound, and further contains a structural unit (A2) which is a structural unit other than the structural unit (A1).
[12] The film according to any one of the above [1] to [11], wherein the polycarbonate resin (B) is a bisphenol-based polycarbonate.
[13] The film according to any one of [1] to [12] above, which is for a card or passport.
[14] A laminate comprising the film according to any one of [1] to [13] above and another film laminated on the film.
[15] The laminate according to the above [14], wherein the other film contains a resin selected from the group consisting of polyester resins and polyvinyl chloride resins.
[16] The laminate according to [15] above, wherein the other film comprises an amorphous polyester.
[17] A method for producing a laminate, comprising laminating the film according to any one of [1] to [13] above onto another film to obtain a laminate.
[18] A card having the film according to any one of [1] to [13] above, or the laminate according to any one of [14] to [16] above.
[19] A passport having the film according to any one of [1] to [13] above, or the laminate according to any one of [14] to [16] above.

According to the present invention, even when using a polycarbonate resin derived from a specific dihydroxy compound such as isosorbide, peeling between fused films can be prevented without increasing the fusion temperature, and interlayer peeling in a multilayer film can be prevented.

FIG. 2 is a schematic diagram showing a layer structure of a card. FIG. 2 is a schematic diagram showing a layer structure of a passport.

The present invention will be described in detail below with reference to the embodiments. However, the present invention is not limited to the embodiments described below. In addition, the terms "film" and "sheet" used in the following description are not clearly distinguished from each other, and the term "film" includes "sheet," and the term "sheet" includes "film."

[Resin layer (1)]
The film of the present invention (hereinafter sometimes referred to as “the present film”) has a resin layer (1) made of a resin composition (1) containing a polycarbonate resin (A) having a specific structural unit described below and a polycarbonate resin (B) other than the polycarbonate resin (A).

(Polycarbonate resin (A))
In the present invention, the polycarbonate resin (A) contained in the resin composition (1) has a structural unit (A1) derived from a dihydroxy compound having a moiety represented by the following formula (1) as part of its structure.

However, this does not include the case where the moiety represented by formula (1) is a part of -CH ₂ -O-H. In other words, the dihydroxy compound refers to one that contains at least two hydroxyl groups and further contains the moiety of formula (1).

In the present invention, by using the polycarbonate resin (A) having the above structure, the biomass degree of the present film and final products such as cards and passports containing the present film can be improved, and the environmental load can be reduced. In addition, by containing the polycarbonate resin (B) described later in addition to the polycarbonate resin (A), the present film can increase the adhesive strength between the fused film and another film containing a resin other than polycarbonate resin such as PETG or PVC, and peeling between the films can be prevented. In addition, when the present film is a multilayer film, the resin layer (1) can be adhered with high adhesive strength to another resin layer (resin layer (2)) containing a component other than polycarbonate resin such as PETG, so that peeling between layers in the multilayer film can also be prevented. Furthermore, in the multilayer film, the adhesive strength between layers in the multilayer film can be increased even if the other resin layer (resin layer (2)) does not contain, for example, a resin component that increases the fusion temperature. Therefore, it can be fused to another film at a relatively low fusion temperature, and has excellent low-temperature fusion properties.

Dihydroxy compounds having a moiety represented by formula (1) as part of their structure are not particularly limited as long as they have a structure represented by formula (1) in the molecule, but specific examples include 9,9-bis(4-(2-hydroxyethoxy)phenyl)fluorene, 9,9-bis(4-(2-hydroxyethoxy)-3-methylphenyl)fluorene, 9,9-bis(4-(2-hydroxyethoxy)-3-isopropylphenyl)fluorene, 9,9-bis(4-(2-hydroxyethoxy)-3-isobutylphenyl)fluorene, 9,9-bis(4-(2-hydroxyethoxy)-3-tert-butylphenyl)fluorene, 9,9-bis(4-(2-hydroxyethoxy)-3-cyclo hexylphenyl)fluorene, 9,9-bis(4-(2-hydroxyethoxy)-3-phenylphenyl)fluorene, 9,9-bis(4-(2-hydroxyethoxy)-3,5-dimethylphenyl)fluorene, 9,9-bis(4-(2-hydroxyethoxy)-3-tert-butyl-6-methylphenyl)fluorene, 9,9-bis(4-(3-hydroxy-2,2-dimethylpropoxy)phenyl)fluorene, and other compounds having aromatic groups on the side chain and ether groups bonded to the aromatic groups on the main chain, as well as dihydroxy compounds having a cyclic ether structure, such as dihydroxy compounds represented by the following formula (2) and spiroglycol represented by the following formula (3).

Among the above, dihydroxy compounds having a cyclic ether structure are preferred, and anhydrous sugar alcohols as represented by formula (2) are particularly preferred. More specifically, dihydroxy compounds represented by formula (2) include isosorbide, isomannide, and isoidet, which are stereoisomers. Dihydroxy compounds represented by formula (3) below include 3,9-bis(1,1-dimethyl-2-hydroxyethyl)-2,4,8,10-tetraoxaspiro(5.5)undecane (common name: spiroglycol), 3,9-bis(1,1-diethyl-2-hydroxyethyl)-2,4,8,10-tetraoxaspiro(5.5)undecane, and 3,9-bis(1,1-dipropyl-2-hydroxyethyl)-2,4,8,10-tetraoxaspiro(5.5)undecane.
These may be used alone or in combination of two or more.

In formula (3), R ₁ to R ₄ each independently represent an alkyl group having 1 to 3 carbon atoms.

The dihydroxy compound represented by the formula (2) is an ether diol that can be produced from carbohydrates using plant-derived substances as raw materials. In particular, isosorbide can be produced inexpensively by hydrogenating and then dehydrating D-glucose obtained from starch, and is abundantly available as a resource. For these reasons, isosorbide is most preferably used.

The polycarbonate resin (A) may further contain a structural unit other than the structural unit (A1) as a structural unit derived from a dihydroxy compound, and preferably contains, for example, a structural unit derived from at least one dihydroxy compound selected from an aliphatic dihydroxy compound and an alicyclic dihydroxy compound (hereinafter sometimes referred to as the structural unit (A2)).

The aliphatic dihydroxy compound is not particularly limited in terms of the number of carbon atoms, but preferably has about 2 to 12 carbon atoms, more preferably has 2 to 6 carbon atoms. Specific examples include ethylene glycol, 1,3-propanediol, 1,4-butanediol, 1,5-pentanediol, neopentyl glycol, 1,6-hexanediol, 1,7-heptanediol, 1,8-octanediol, 1,9-nonanediol, 2-ethyl-1,6-hexanediol, 2,2,4-trimethyl-1,6-hexanediol, 1,10-decanediol, 1,12-dodecanediol, hydrogenated dilinoleyl glycol, hydrogenated dioleyl glycol, etc. Preferably, at least one selected from ethylene glycol, 1,3-propanediol, 1,4-butanediol, 1,5-pentanediol, 1,6-hexanediol, 1,9-nonanediol, 1,10-decanediol, and 1,12-dodecanediol is used, and more preferably, at least one selected from ethylene glycol, 1,3-propanediol, 1,4-butanediol, 1,5-pentanediol, and 1,6-hexanediol is used. In addition, as the structural unit derived from an aliphatic dihydroxy compound, for example, those described in WO 2004/111106 can also be used.

The structural unit derived from the alicyclic dihydroxy compound preferably contains at least one of a 5-membered ring structure and a 6-membered ring structure, and in particular the 6-membered ring structure may be fixed in a chair or boat shape by a covalent bond. By containing a structural unit derived from an alicyclic dihydroxy compound having such a structure, the heat resistance of the resulting polycarbonate resin (A) can be improved.
The alicyclic dihydroxy compound contains, for example, 5 to 70 carbon atoms, preferably 6 to 50 carbon atoms, and more preferably 8 to 30 carbon atoms.
The alicyclic dihydroxy compound is preferably at least one selected from cyclohexanedimethanol, tricyclodecane dimethanol, adamantanediol, and pentacyclopentadecanedimethanol, and from the viewpoints of economy and heat resistance, cyclohexanedimethanol or tricyclodecane dimethanol is more preferred, and cyclohexanedimethanol is even more preferred. As for cyclohexanedimethanol, 1,4-cyclohexanedimethanol is particularly preferred from the viewpoint of industrial availability.
In addition, as the structural unit derived from an alicyclic dihydroxy compound, those described in WO 2007/148604 can also be used.

The content of the structural unit (A1) in the polycarbonate resin (A) is preferably 30 mol% or more, more preferably 40 mol% or more, even more preferably 45 mol% or more, and also preferably 80 mol% or less, more preferably 75 mol% or less, even more preferably 70 mol% or less, and even more preferably 65 mol% or less, in the structural units derived from the dihydroxy compound. By setting it in such a range, coloring caused by the carbonate structure and coloring caused by impurities contained in trace amounts because of the use of plant resource materials can be effectively suppressed, the transparency of the present film is easily increased, and yellowing is easily prevented. In addition, it tends to be possible to achieve a suitable balance of physical properties such as moldability, mechanical strength, and heat resistance, which is difficult to achieve with a polycarbonate resin composed only of the structural unit (A1).
On the other hand, the content of the structural unit (A2) in the polycarbonate resin (A) in the structural units derived from the dihydroxy compound is preferably 20 mol % or more, more preferably 25 mol % or more, even more preferably 30 mol % or more, still more preferably 35 mol % or more, and is preferably 70 mol % or less, more preferably 60 mol % or less, and even more preferably 55 mol % or less.

In the polycarbonate resin (A), the structural unit derived from the dihydroxy compound is preferably composed of the structural unit (A1) and the structural unit (A2), but may contain structural units derived from other dihydroxy compounds as long as the object of the present invention is not impaired. Specifically, a small amount of an aromatic ring-containing dihydroxy compound, such as bisphenol, such as 2,2-bis(4-hydroxyphenyl)propane (commonly known as bisphenol A), may be copolymerized. The use of an aromatic ring-containing dihydroxy compound is expected to efficiently improve heat resistance and moldability, but the incorporation of a large amount of the compound tends to cause problems in weather resistance, so it is preferable to use an amount that does not cause problems in weather resistance.
Examples of aromatic ring-containing dihydroxy compounds other than bisphenol A include α,α'-bis(4-hydroxyphenyl)-m-diisopropylbenzene (bisphenol M), 9,9-bis(4-hydroxy-3-methylphenyl)fluorene, 1,1-bis(4-hydroxyphenyl)cyclohexane, 1,1-bis(4-hydroxyphenyl)-3,3,5-trimethylcyclohexane, 4,4'-dihydroxy-3,3'-dimethyldiphenyl sulfide, 2,2-bis(4-hydroxy-3-methylphenyl)propane (bisphenol C), 2,2-bis(4-hydroxyphenyl)-1,1,1,3,3,3-hexafluoropropane (bisphenol AF), and 1,1-bis(4-hydroxyphenyl)decane.

The glass transition temperature of the polycarbonate resin (A) is, for example, 70° C. or higher, preferably 80° C. or higher, more preferably 85° C. or higher, and even more preferably 90° C. or higher, and is, for example, 140° C. or lower, preferably 130° C. or lower, more preferably 125° C. or lower, and even more preferably 120° C. or lower. It is usually preferred that the polycarbonate resin (A) has a single glass transition temperature.
By setting the glass transition temperature to the above upper limit or lower, peeling between the present film and another film is unlikely to occur even when the film is fused to another film at a low temperature or the temperature during the formation of the multilayer film is low, and interlayer peeling is also unlikely to occur within the multilayer film. On the other hand, by setting the glass transition temperature to the above lower limit or higher, it becomes easier to impart heat resistance to the film.
The glass transition temperature can be adjusted by appropriately selecting the ratio of each structural unit constituting the polycarbonate resin (A). The glass transition temperature of each resin can be obtained by measurement using a viscoelasticity spectrometer. Specifically, the temperature dispersion measurement of dynamic viscoelasticity is performed under conditions of strain 0.07%, frequency 1 Hz, and heating rate 3°C/min, and the temperature showing the peak of the main dispersion of the loss tangent (tan δ) is taken as the glass transition temperature. In addition, when there are two peaks, the lower side is taken as the glass transition temperature. Specific measurements can be performed, for example, using "DVA-200" (manufactured by IT Measurement and Control Co., Ltd.) with reference to JIS K7244-4:1999.

The deflection temperature under load of the polycarbonate resin (A) is, for example, 60° C. or more, preferably 70° C. or more, more preferably 75° C. or more, and even more preferably 80° C. or more, and is, for example, 120° C. or less, preferably 110° C. or less, more preferably 100° C. or less, and even more preferably 95° C. or less.
By setting the deflection temperature under load to the above upper limit or lower, peeling between the present film and another film is unlikely to occur even when the film is fused to another film at a low temperature or the temperature during the formation of the multilayer film is low, and interlayer peeling is also unlikely to occur within the multilayer film. On the other hand, by setting the deflection temperature under load to the above lower limit or higher, it becomes easier to impart heat resistance to the film.
The deflection temperature under load can be adjusted by appropriately selecting the ratio of each structural unit constituting the polycarbonate resin (A). The deflection temperature under load of each resin can be measured by JIS K7191-2:2015 Method A (bending stress of 1.80 MPa applied to the test piece).

The polycarbonate resin (A) can be produced by a commonly used polymerization method, and can be produced by either the phosgene method (interfacial polymerization method) or the transesterification method (melt polymerization method) of reacting with a carbonate diester. Among them, the transesterification method of reacting a dihydroxy compound having a site represented by the formula (1) in a part of its structure with another dihydroxy compound with a carbonate diester in the presence of a polymerization catalyst is preferred. The transesterification method is a polymerization method in which a dihydroxy compound, a carbonate diester, a basic catalyst, and an acidic substance for neutralizing the catalyst are mixed to carry out a transesterification reaction.
Examples of the carbonic acid diester include diphenyl carbonate, ditolyl carbonate, bis(chlorophenyl) carbonate, m-cresyl carbonate, dinaphthyl carbonate, bis(biphenyl) carbonate, diethyl carbonate, dimethyl carbonate, dibutyl carbonate, and dicyclohexyl carbonate, and among these, diphenyl carbonate is preferably used.

The molecular weight of the polycarbonate resin (A) can be represented by a reduced viscosity, and the reduced viscosity is, from the viewpoint of imparting mechanical strength, for example, 0.3 dL/g or more, and preferably 0.35 dL/g or more, and from the viewpoint of increasing fluidity during molding and improving productivity and moldability, for example, 1.2 dL/g or less, preferably 1 dL/g or less, and more preferably 0.8 dL/g or less.
The reduced viscosity is measured by using dichloromethane as a solvent, precisely adjusting the polycarbonate resin concentration to 0.6 g/dL, and using an Ubbelohde viscometer at a temperature of 20.0° C.±0.1° C.

The proportion of polycarbonate resin (A) in the resin composition (1) is preferably 5% by mass or more and less than 90% by mass. By making it 5% by mass or more, a certain amount or more of plant-derived components can be contained in the film, and the environmental load can be reduced. In addition, when it is made into a single-layer film or when the resin layer (1) is made into the outermost layer of a multilayer film, it is easy to fuse it to another film at a low temperature. In addition, in a multilayer film, even if it is molded at a low temperature, peeling is unlikely to occur between layers in the film. On the other hand, by making the above proportion less than 90% by mass, it is easy to make the proportion of polycarbonate resin (B) described later to be a certain amount or more, or to make the resin layer (1) contain an appropriate amount of components other than the polycarbonate resin.
The proportion of the polycarbonate resin (A) in the resin composition (1) is more preferably 15 mass% or more, even more preferably 20 mass% or more, even more preferably 30 mass% or more, even more preferably 50 mass% or more, even more preferably 55 mass% or more, and more preferably 85 mass% or less, even more preferably 80 mass% or less, even more preferably 75 mass% or more, and even more preferably 73 mass% or less.

(Polycarbonate resin (B))
As the polycarbonate resin (B), a polycarbonate resin other than the polycarbonate resin (A) having the above-mentioned structural unit (A1) may be used. In this way, the resin layer (1) contains another type of polycarbonate resin (B) in addition to the polycarbonate resin (A), and therefore, even if the resin layer (1) is fused to another film containing a resin component other than the polycarbonate resin, such as PETG or PVC, the adhesive strength between the fused film and the film can be easily increased. Also, in the case of a multilayer film, the adhesive strength with a layer containing a resin component other than the polycarbonate resin (resin layer (2) described later) can be increased, and delamination in the multilayer film can be easily prevented.

In the present invention, as the polycarbonate resin (B), a polycarbonate having an aromatic ring is preferred, and among them, it is more preferred to use a bisphenol-based polycarbonate. By using a polycarbonate resin having an aromatic ring, such as a bisphenol-based polycarbonate, the resin composition (1) has both an aliphatic group and an aromatic ring in the polycarbonate resin. Therefore, it is easy to increase the adhesive strength to layers and films containing resin components other than the above-mentioned polycarbonate resin. In addition, by containing the polycarbonate resin (B) in the resin composition (1), it is easy to make the mechanical properties, heat resistance, etc. of the present film excellent.

Bisphenol-based polycarbonates are those in which 50 mol% or more, preferably 70 mol% or more, and more preferably 90 mol% or more of the structural units derived from dihydroxy compounds are structural units derived from bisphenols. Bisphenol-based polycarbonates may be either homopolymers or copolymers. Bisphenol-based polycarbonates may also have a branched structure or a linear structure, or may be a mixture of a resin having a branched structure and a resin having only a linear structure.

Specific examples of bisphenols include 2,2-bis(4-hydroxyphenyl)propane (bisphenol A), 1,1-bis(4-hydroxyphenyl)-1-phenylethane (bisphenol AP), 2,2-bis(4-hydroxyphenyl)hexafluoropropane (bisphenol AF), 2,2-bis(4-hydroxyphenyl)butane (bisphenol B), bis(4-hydroxyphenyl)diphenylmethane (bisphenol BP), 2,2-bis(3-methyl-4-hydroxyphenyl)propane (bisphenol C), 1,1-bis(4-hydroxyphenyl)ethane (bisphenol E), bis(4-hydroxyphenyl)methane (bisphenol F), 2,2-bis( 4-hydroxy-3-isopropylphenyl)propane (bisphenol G), 1,3-bis(2-(4-hydroxyphenyl)-2-propyl)benzene (bisphenol M), bis(4-hydroxyphenyl)sulfone (bisphenol S), 1,4-bis(2-(4-hydroxyphenyl)-2-propyl)benzene (bisphenol P), 5,5'-(1-methylethylidene)-bis[1,1'-(bisphenyl)-2-ol]propane (bisphenol PH), 1,1-bis(4-hydroxyphenyl)3,3,5-trimethylcyclohexane (bisphenol TMC), and 1,1-bis(4-hydroxyphenyl)cyclohexane (bisphenol Z). Bisphenols may be used alone or in combination of two or more.

As the bisphenol, 2,2-bis(4-hydroxyphenyl)propane, ie, bisphenol A, is preferably used, but a part of bisphenol A may be replaced with another bisphenol.
Of the structural units derived from the dihydroxy compound, the structural units derived from bisphenol A are preferably 50 mol % or more, more preferably 70 mol % or more, even more preferably 90 mol % or more, and most preferably 100 mol %. Therefore, the most preferred polycarbonate resin (B) is bisphenol A homopolycarbonate.

The bisphenol-based polycarbonate used as the polycarbonate resin (B) may be produced by any known method such as the phosgene method (interfacial polymerization method), the ester exchange method (melt polymerization method) and the pyridine method.
For example, the transesterification method is a production method in which bisphenol and a carbonic acid diester are subjected to melt transesterification polycondensation by adding a basic catalyst and an acidic substance that neutralizes the basic catalyst. Specific examples of the carbonic acid diester are as listed in the above polycarbonate resin (A), and diphenyl carbonate is particularly preferably used.

The glass transition temperature of the polycarbonate resin (B) is typically higher than that of the polycarbonate resin (A), and is, for example, 110° C. or higher and 200° C. or lower. It is also preferably 125° C. or higher, more preferably 135° C. or higher, and even more preferably 140° C. or higher, and is also preferably 175° C. or lower, more preferably 170° C. or lower, and even more preferably 165° C. or lower. The polycarbonate resin (B) usually has a single glass transition temperature.
The polycarbonate resin (B) is likely to have appropriate heat resistance by having a glass transition temperature of 110° C. or higher. On the other hand, by having a glass transition temperature of 200° C. or lower, the low-temperature fusion property is good even in a single-layer film or a multilayer film in which the resin layer (1) is the outermost layer. In addition, the formability of the film is also likely to be good.

The deflection temperature under load of the polycarbonate resin (B) is, for example, 90°C or higher, preferably 100°C or higher, more preferably 110°C or higher, and even more preferably 120°C or higher, and is, for example, 170°C or lower, preferably 160°C or lower, more preferably 150°C or lower, and even more preferably 145°C or lower. By making the deflection temperature under load equal to or higher than the lower limit, it becomes easier to have appropriate heat resistance. On the other hand, by making the temperature 170°C or lower, the low-temperature fusion property becomes good even in a single-layer film or a multilayer film in which the resin layer (1) is the outermost layer. In addition, the moldability of the present film is also easily improved. The deflection temperature under load of the polycarbonate resin (B) is preferably higher than the deflection temperature under load of the polycarbonate resin (A) described above.
The deflection temperature under load can be adjusted by appropriately selecting the ratio of each structural unit constituting the polycarbonate resin (B). The deflection temperature under load of each resin can be measured by JIS K7191-2:2015 Method A (bending stress of 1.80 MPa applied to the test piece).

The melt volume rate (300°C, 1.2 kgf) of the polycarbonate resin (B) is preferably 1 ^cm3 /10 min or more, more preferably 2 cm3/10 min or more, even more preferably 3 ^cm3 /10 min or more, and preferably 60 ^cm3 /10 min or less, more preferably 50 ^cm3 /10 min or less, even more preferably 40 ^cm3 /10 min or less, and still more preferably 30 ^cm3 / ¹⁰ min, from the viewpoints of mechanical properties and moldability. The melt volume rate of the polycarbonate resin (B) can be measured in accordance with ISO 1133.

The mass average molecular weight of the polycarbonate resin (B) is usually 10,000 or more, preferably 30,000 or more, and usually 100,000 or less, preferably 80,000 or less, in consideration of the balance between the mechanical properties and the moldability. The number average molecular weight of the polycarbonate resin (B) is usually 10,000 or more, preferably 20,000 or more, and usually 50,000 or less, preferably 40,000 or less, in consideration of the balance between the mechanical properties and the moldability. The mass average molecular weight and the number average molecular weight can be measured by gel permeation chromatography (GPC) using polystyrene as a standard substance.
The viscosity average molecular weight of the polycarbonate resin (B) is usually 12000 or more, preferably 15000 or more, more preferably 20000 or more, and even more preferably 22000 or more, in consideration of the balance between mechanical properties and moldability, and is usually 40000 or less, preferably 35000 or less, more preferably 30000 or less, and even more preferably 28000 or less. The viscosity average molecular weight can be measured by using dichloromethane as a solvent, determining the intrinsic viscosity ([η]) (unit: dl/g) at a temperature of 20° C. using an Ubbelohde viscometer, and calculating from Schnell's viscosity formula: η = 1.23 × 10 ^-4 M ^0.83 .
In addition, the dispersity represented by the ratio of the mass average molecular weight to the number average molecular weight (Mw/Mn) of the polycarbonate resin (B) is not particularly limited, and is, for example, 1.1 or more and 10 or less, preferably 1.5 or more and 6 or less, more preferably 1.8 or more and 5 or less, and further preferably 2 or more and 4 or less.

The proportion of the polycarbonate resin (B) in the resin composition (1) is preferably more than 10% by mass and not more than 90% by mass. By containing more than 10% by mass of the polycarbonate resin (B), the adhesive strength to another film containing a resin component other than the polycarbonate resin or to another layer in the multilayer film can be increased, and peeling between fused films and peeling between layers in the multilayer film can be easily prevented. Furthermore, the mechanical strength of the film can be easily improved. On the other hand, by making it 90% by mass or less, it becomes easier to contain a certain amount or more of the above-mentioned polycarbonate resin (A) in the resin layer (1), and the environmental load can also be easily reduced.
From the above viewpoints, the proportion of the polycarbonate resin (B) in the resin composition (1) is more preferably 12 mass% or more, even more preferably 15 mass% or more, still more preferably 20 mass% or more, and more preferably 80 mass% or less, even more preferably 60 mass% or less, still more preferably 50 mass% or less, and still more preferably 40 mass% or less.

The content ratio ((A)/(B)) of the polycarbonate resin (A) and the polycarbonate resin (B) in the resin composition (1) is preferably 20/80 or more and 95/5 or less in mass ratio. When the content ratio ((A)/(B)) is within the above range, even if the film is fused at a relatively low temperature or a multilayer film is formed at a low temperature, the adhesive strength to another film or to the resin layer (2) described later can be easily increased. In addition, when the content ratio is 20/80 or more, the environmental load can be easily reduced, while when the content ratio is 95/5 or less, the mechanical strength of the film can be easily improved.
From these viewpoints, the content ratio ((A)/(B)) is more preferably 30/70 or more, even more preferably 40/60 or more, even more preferably 50/50 or more, and even more preferably 55/45 or more. Also, the content ratio ((A)/(B)) is more preferably 88/12 or less, even more preferably 85/15 or less, and even more preferably 80/20 or less.

(Filling material)
The resin composition (1) for forming the film (1) preferably contains a filler. By containing the filler, the resin composition (1) has low light transmittance and can exhibit, for example, concealment properties. Therefore, the film can be suitably used for cards and passports, and can be suitably used for core sheets in particular.

The filler may be either an inorganic filler or an organic filler, and examples of such fillers include inorganic fillers such as titanium oxide, talc, mica, calcium carbonate, magnesium carbonate, barium oxide, carbon black, silica, lead titanate, potassium titanate, barium titanate, zirconium oxide, magnesium oxide, calcium oxide, aluminum oxide, zinc sulfide, antimony oxide, zinc oxide, boron nitride, aluminum nitride, and barium sulfate. Among these, at least one type selected from fillers having a refractive index of 2 or more is preferred, and the refractive index is more preferably 2.2 or more, and even more preferably 2.4 or more. Examples of fillers having a refractive index of 2 or more include titanium oxide, lead titanate, potassium titanate, barium titanate, zirconium oxide, magnesium oxide, calcium oxide, zinc sulfide, antimony oxide, zinc oxide, aluminum oxide, boron nitride, aluminum nitride, calcium carbonate, magnesium carbonate, and barium sulfate. By using a filler having a refractive index of 2 or more, the hiding property becomes even better and it is easier to color it white. From these points of view, titanium oxide is more preferable as the filler. Examples of titanium oxide include, but are not limited to, rutile-type titanium oxide and anatase-type titanium oxide. The refractive index of the filler can be measured by the Becke line method.

The average particle size of the filler is not particularly limited, but is, for example, 0.01 μm to 1 μm, preferably 0.05 μm to 0.8 μm, more preferably 0.08 μm to 0.6 μm, even more preferably 0.1 μm to 0.5 μm, and even more preferably 0.12 μm to 0.4 μm. The average particle size refers to the average primary particle size observed with a scanning electron microscope.

The content of the filler in the resin composition (1) is preferably 3 parts by mass or more and 70 parts by mass or less with respect to 100 parts by mass of the resin component contained in the resin composition (1). By making the content of the filler 3 parts by mass or more, the concealing property of the present film can be improved. In addition, by making the content of the filler 70 parts by mass or less, it becomes easier to maintain good mechanical properties such as bending resistance. In addition, it becomes easier to prevent yellowing even when titanium oxide or the like is blended. From these viewpoints, the content of the filler is more preferably 5 parts by mass or more, even more preferably 8 parts by mass or more, and even more preferably 10 parts by mass or more. In addition, the content of the filler is more preferably 60 parts by mass or less, even more preferably 55 parts by mass or less, even more preferably 50 parts by mass or less, even more preferably 45 parts by mass or less, and even more preferably 40 parts by mass or less.

(Metal salt stabilizer)
The resin composition (1) may contain a metal salt stabilizer. When the resin composition (1) contains the polycarbonate resin (A), if a film having the resin layer (1) is left in a high-temperature and high-humidity environment, it may turn yellow due to the filler, but when the resin composition (1) contains the metal salt stabilizer, it is possible to ensure resistance to moist heat and make the film less likely to turn yellow.

The metal salt stabilizer is not particularly limited as long as it is a metal salt, but for example, a metal salt having an aliphatic group can be used. Examples of the aliphatic group include an aliphatic hydrocarbon group and an aliphatic acyl group. The aliphatic group is not particularly limited, but preferably has 4 or more carbon atoms, more preferably has 6 or more carbon atoms, even more preferably has 8 or more carbon atoms, even more preferably has 10 or more carbon atoms, even more preferably has 12 or more carbon atoms, and also preferably has 30 or less carbon atoms, more preferably has 26 or less carbon atoms, even more preferably has 24 or less carbon atoms, even more preferably has 20 or less carbon atoms, even more preferably has 18 or less carbon atoms, and even more preferably has 16 or less carbon atoms.
The metal salt is a salt of a metal such as lithium, sodium, aluminum, calcium, zinc, magnesium, lead, copper, or barium. Among these, from the viewpoint of resistance to moist heat, zinc salts, magnesium salts, calcium salts, aluminum salts, and copper salts are preferred, and among these, zinc salts are more preferred.

Specific examples of the metal salt include metal salts of fatty acids and metal salts of alkylbenzenesulfonic acids, with the metal salts of fatty acids being preferred.
The metal alkylbenzenesulfonate includes metal alkylbenzenesulfonates having an alkyl group with preferably 8 to 24 carbon atoms, more preferably 10 to 16. A specific example of the metal alkylbenzenesulfonate is sodium dodecylbenzenesulfonate.

The fatty acid metal salt is a salt of a fatty acid and the above metal. The fatty acid in the fatty acid metal salt may be a straight-chain fatty acid or a branched-chain fatty acid. In addition, it may be a saturated fatty acid or an unsaturated fatty acid, but from the viewpoint of moisture and heat resistance, the saturated fatty acid is preferred.
In addition, the fatty acid may be a hydroxy fatty acid having a hydroxy group other than a carboxyl group, or may be a fatty acid having no hydroxy group other than a carboxyl group, but from the viewpoint of improving the wet heat resistance and suppressing yellowing, a hydroxy fatty acid is preferred. In addition, from the viewpoint of easily producing the fatty acid, a fatty acid having no hydroxy group other than a carboxyl group is preferred. Furthermore, a hydroxy fatty acid and a fatty acid other than a hydroxy fatty acid may be used in combination.

Examples of fatty acids include fatty acids having, for example, 4 to 30 carbon atoms, preferably 6 to 26, more preferably 8 to 24, even more preferably 10 to 20, even more preferably 12 to 18, and even more preferably 12 to 16. By setting the number of carbon atoms of the fatty acid within the above range, it is possible to improve the moist heat resistance of the resin composition while maintaining the dispersibility of the metal salt-based stabilizer, making it easier to suppress yellowing.

Specific preferred examples of fatty acid metal salts include zinc laurate, zinc myristate, zinc palmitate, zinc stearate, zinc 12-hydroxystearate, magnesium laurate, magnesium myristate, magnesium palmitate, magnesium stearate, magnesium 12-hydroxystearate, calcium laurate, calcium myristate, calcium palmitate, calcium stearate, calcium 12-hydroxystearate, aluminum laurate, aluminum myristate, aluminum palmitate, aluminum stearate, aluminum 12-hydroxystearate, copper laurate, copper myristate, copper palmitate, copper stearate, and copper stearate.
Of these, zinc stearate, zinc laurate, zinc 12-hydroxystearate, magnesium 12-hydroxystearate, calcium 12-hydroxystearate, and aluminum stearate are more preferable, and from the viewpoint of improving the dispersibility of the metal salt-based stabilizer and the moist heat resistance of the resin composition in a well-balanced manner and further improving yellowing, zinc laurate, zinc 12-hydroxystearate, magnesium 12-hydroxystearate, and calcium 12-hydroxystearate are even more preferable, and zinc laurate and zinc 12-hydroxystearate are most preferable.
The metal salt stabilizers may be used alone or in combination of two or more kinds.

The content of the metal salt stabilizer is preferably 0.01 parts by mass or more and 3 parts by mass or less relative to 100 parts by mass of the resin component contained in the resin composition (1). By making it 0.01 parts by mass or more, the metal salt stabilizer can appropriately improve the moist heat resistance, and yellowing is unlikely to occur even when used in a high temperature and high humidity environment. In addition, by making it 3 parts by mass or less, it is easy to exert an effect commensurate with the content.
From the above viewpoint, the content of the metal salt stabilizer is more preferably 0.05 parts by mass or more, even more preferably 0.1 parts by mass or more, even more preferably 0.15 parts by mass or more, even more preferably 0.2 parts by mass or more, even more preferably 0.25 parts by mass or more. In addition, by reducing the content of the metal salt stabilizer, it becomes easier to maintain the mechanical strength of the resin composition well, for example, it becomes easier to ensure the stretchability, and it becomes easier to increase the tensile elongation of the present film. From such a viewpoint, the content of the metal salt stabilizer is more preferably 2.5 parts by mass or less, even more preferably 2 parts by mass or less, even more preferably 1.5 parts by mass or less, even more preferably 1 part by mass or less.

The presence or absence of metal salt stabilizers in the resin composition can be confirmed, for example, by detecting metal elements using inductively coupled plasma atomic emission spectrometry (ICP-AES) and detecting esters having aliphatic groups using gas chromatography mass spectrometry (GC-MS). Esters having aliphatic groups can also be detected by subjecting components that are insoluble in good solvents for polycarbonate resin (A), such as tetrahydrofuran and chloroform, to methanol decomposition and detection using GC-MS of the decomposition product, or by extracting the components with heated methanol and detecting the extracted components using reactive pyrolysis GC-MS.

(Other resin components)
As described above, the resin composition (1) may contain resin components (also referred to as "other resin components") other than the polycarbonate resins (A) and (B). As such resin components, it is preferable to use a known resin that is widely used, and it is preferable to use a resin that is compatible with the polycarbonate resin (A).
The other resin components are preferably thermoplastic resins, and examples thereof include polyester resins, polyolefin resins, acrylic resins, polystyrene resins, polyamide resins, polyvinyl chloride resins (PVC), polyvinylidene chloride resins, polyvinyl alcohol resins, ethylene-vinyl alcohol resins, polycycloolefin resins, ethylene-vinyl acetate copolymer resins, ethylene (meth)acrylate copolymer resins, polyphenylene ether resins, polyacetal resins, acrylonitrile-butadiene-styrene copolymer resins, polyaryl ether ketone resins, polyimide resins, polyphenylene sulfide resins, polyarylate resins, polysulfone resins, polyether sulfone resins, and fluororesins.

The resin composition (1) may contain components other than the polycarbonate resins (A) and (B), fillers blended as necessary, metal stabilizers, and other resin components, and may contain, for example, additives other than these (also referred to as other additives). Examples of other additives include laser coloring agents, impact absorbing agents, antioxidants, heat stabilizers, process stabilizers, ultraviolet absorbers, light stabilizers, matting agents, processing aids, plasticizers, metal deactivators, residual polymerization catalyst deactivators, antibacterial and antifungal agents, antiviral agents, antistatic agents, lubricants, flame retardants, pigments, dyes, and other colorants, which are generally used in a wide range of resin materials. These additives may also be added in amounts normally used depending on the purpose of use. These additives may be used alone or in combination of two or more.
When the resin composition (1) or the resin composition (2) described later contains, for example, a laser color-developing agent, the present film can be used as a laser marking sheet that develops color when irradiated with a laser.

The film may be a monolayer film having one resin layer, or a multilayer film having two or more resin layers. The monolayer film is made of a single layer of the resin layer (1) described above. The multilayer film has multiple resin layers, and although it is sufficient that at least one of the multiple resin layers is the resin layer (1) described above, it is preferable that the film has both the resin layer (1) and the resin layer (2) described below.

[Resin layer (2)]
The resin layer (2) is made of a resin composition (2) other than the above-mentioned resin composition (1). The resin composition (2) may contain a resin component other than a polycarbonate resin, and the resin component is preferably a thermoplastic resin. Specifically, the resin component may be appropriately selected from the resins listed as other resin components in the above-mentioned resin layer (1) and used. In the resin composition (2), one type of resin may be used alone, or two or more types may be used in combination.
In addition, the resin composition (2) may contain a polycarbonate resin in addition to resin components other than the polycarbonate resin, as long as the effects of the present invention are achieved. The polycarbonate resin may be the above-mentioned polycarbonate resin (A) or polycarbonate resin (B).

Among the above, the resin composition (2) preferably contains at least one of a polyester resin and a polyvinyl chloride resin, and among these, a polyester resin is preferable. By containing a resin component other than a polycarbonate resin, particularly a polyester resin, in the resin composition (2), the present film is heat-sealed to another film via the resin layer (2), which makes it easier to increase the adhesive strength between the films and makes it difficult for peeling to occur between the present film and the other film. In addition, it also becomes easier to prevent interlayer peeling between the resin layer (1) and the resin layer (2) in the multilayer film.

(Polyvinyl chloride resin)
Examples of polyvinyl chloride resins that can be used in the resin composition (2) include homopolymers or copolymers of vinyl chloride. Monomers that can be copolymerized with vinyl chloride are not limited, but examples include ethylene, propylene, acrylonitrile, vinyl acetate, maleic acid or its ester, acrylic acid or its ester, methacrylic acid or its ester, vinylidene chloride, and the like. The resin may also be a partially crosslinked resin. A polymer blend of polyvinyl chloride resins, for example, a polymer blend consisting of vinyl chloride resin and polyvinylidene chloride, may also be used. Furthermore, the polyvinyl chloride resin may be a chlorinated polyvinyl chloride resin. The polyvinyl chloride resin may be a hard polyvinyl chloride resin or a soft polyvinyl chloride resin, but is preferably a hard polyvinyl chloride resin. By using a hard polyvinyl chloride resin, it is easier to impart mechanical strength suitable for cards and passports.

(Polyester resin)
The polyester resin used in the resin composition (2) may be, for example, a polyester obtained by polycondensation of a dicarboxylic acid and a dihydroxy compound. As the dicarboxylic acid, a dicarboxylic acid derivative such as an ester or an acid halide of the dicarboxylic acid may be used for the synthesis of the polyester resin.

As the dicarboxylic acid used to obtain the polyester resin, it is preferable to use an aromatic dicarboxylic acid from the viewpoint of heat resistance, and therefore the polyester resin preferably contains structural units derived from an aromatic dicarboxylic acid.
The aromatic dicarboxylic acid is not particularly limited, and examples thereof include terephthalic acid, isophthalic acid, naphthalene-1,4-dicarboxylic acid, naphthalene-2,6-dicarboxylic acid, naphthalene-2,7-dicarboxylic acid, naphthalene-1,5-dicarboxylic acid, anthracene dicarboxylic acid, 4,4'-diphenyl dicarboxylic acid, 4,4'-diphenyl ether dicarboxylic acid, 5-sulfoisophthalic acid, 3-sodium sulfoisophthalate, 2-chloroterephthalic acid, 2,5-dichloroterephthalic acid, 2-methylterephthalic acid, and the like. Of these, terephthalic acid and isophthalic acid are preferred, and terephthalic acid is more preferred.
The aromatic dicarboxylic acids may be used alone or in combination of two or more.

The aromatic dicarboxylic acid-derived structural units are preferably contained in the dicarboxylic acid-derived structural units in the polyester resin in an amount of, for example, 60 mol% or more, preferably 70 mol% or more, more preferably 80 mol% or more, and even more preferably 90 mol% or more. There is no particular upper limit, and it is sufficient if it is 100 mol% or less, but it is most preferably 100 mol%.

In addition to the structural units derived from aromatic dicarboxylic acids, the polyester resin may contain a small amount of structural units derived from aliphatic dicarboxylic acids (usually 40 mol% or less, for example 30 mol% or less, preferably 20 mol% or less). There are no particular limitations on the aliphatic dicarboxylic acids, and examples of such acids include oxalic acid, succinic acid, glutaric acid, adipic acid, pimelic acid, sebacic acid, azelaic acid, dodecanedioic acid, dimer acid, 1,3 or 1,4-cyclohexanedicarboxylic acid, cyclopentanedicarboxylic acid, and 4,4'-dicyclohexyldicarboxylic acid. The aliphatic dicarboxylic acids may be used alone or in combination of two or more.

The polyester resin preferably contains a structural unit derived from a chain dihydroxy compound. By containing a structural unit derived from a chain dihydroxy compound, the polyester resin can easily fuse the present film to another film at a relatively low temperature with high adhesiveness. In addition, the adhesive strength between the resin layer (1) and the resin layer (2) in the multilayer film can be easily increased.
The chain dihydroxy compound used in the polyester resin may be linear or may have a branched structure. Specific examples of the chain dihydroxy compound include chain dihydroxy compounds having about 2 to 18 carbon atoms, such as ethylene glycol (EG), diethylene glycol, 1,2-propylene glycol, 1,3-propanediol, 2,2-dimethyl-1,3-propanediol, 1,4-butanediol, neopentyl glycol, 1,5-pentanediol, 1,6-hexanediol, 1,7-heptanediol, 1,8-octanediol, 1,10-decanediol, 1,12-dodecanediol, triethylene glycol, 1,2-hexadecanediol, and 1,18-octadecanediol, and polyglycols, such as polytetramethylene ether glycol, polypropylene glycol, and polyethylene glycol. Among these, a chain dihydroxy compound having 2 to 12 carbon atoms is preferred, and one or more selected from ethylene glycol, diethylene glycol, 1,3-propanediol, 1,4-butanediol, 1,5-pentanediol, and 1,6-hexanediol are more preferred, with ethylene glycol (EG) being particularly preferred.
The chain dihydroxy compound may be used alone or in combination of two or more kinds.

The polyester resin is preferably a copolymer polyester resin using two or more dihydroxy compounds as copolymerization components.Specifically, it is preferable to use an alicyclic dihydroxy compound in addition to a chain dihydroxy compound as the dihydroxy compound used to obtain the polyester resin.Therefore, it is preferable that the polyester resin has a structural unit derived from an alicyclic dihydroxy compound in addition to a structural unit derived from a chain dihydroxy compound.By using an alicyclic dihydroxy compound, the heat resistance, solvent resistance, etc. are easily improved.
Specific examples of alicyclic dihydroxy compounds include tetramethylcyclobutanediol, cyclohexanedimethanol (CHDM), tricyclodecane dimethanol, adamantanediol, and pentacyclopentadecanedimethanol. Of these, tetramethylcyclobutanediol and cyclohexanedimethanol are preferred. Examples of cyclohexanedimethanol include 1,2-cyclohexanedimethanol, 1,3-cyclohexanedimethanol, and 1,4-cyclohexanedimethanol, with 1,4-cyclohexanedimethanol being preferred from the viewpoint of industrial availability. In addition, 2,2,4,4-tetramethyl-1,3-cyclobutanediol is generally used as tetramethylcyclobutanediol.
The alicyclic dihydroxy compound may be used alone or in combination of two or more. As the alicyclic dihydroxy compound, it is preferable to use at least cyclohexanedimethanol, and it is also preferable to use tetramethylcyclobutanediol and cyclohexanedimethanol in combination.

In the polyester resin, the proportion of structural units derived from alicyclic dihydroxy compounds is, for example, 5 mol% or more, preferably 15 mol% or more, more preferably 20 mol% or more, and for example, 99 mol% or less, preferably 95 mol% or less, more preferably 90 mol% or less, and even more preferably 80 mol% or less, out of a total of 100 mol% of structural units derived from chain dihydroxy compounds and chain dihydroxy compounds. By containing a certain amount or more of structural units derived from alicyclic dihydroxy compounds, the polyester resin is likely to have good heat resistance. In addition, by containing a certain amount or less of structural units derived from alicyclic dihydroxy compounds and a certain amount or more of structural units derived from chain dihydroxy compounds, the low-temperature fusion property is likely to be good.

In the total of 100 mol % of the structural units derived from chain dihydroxy compounds and the structural units derived from alicyclic dihydroxy compounds, the proportion of the structural units derived from alicyclic dihydroxy compounds is preferably 65 mol % or less, more preferably 55 mol % or less, even more preferably 45 mol % or less, and even more preferably 40 mol % or less. By making it equal to or less than these upper limit values, it becomes easier to increase the adhesive strength between films or between layers even when fusion-bonded to another film at low temperature or formed into a multilayer film at low temperature.
However, in terms of heat resistance and solvent resistance, particularly in terms of storage modulus and thermal expansion/contraction rate under high temperature environments, the polyester resin preferably contains structural units derived from alicyclic dihydroxy compounds in a total of 100 mol % of structural units derived from chain dihydroxy compounds and structural units derived from alicyclic dihydroxy compounds, the proportion of which is preferably more than 65 mol %, more preferably 70 mol % or more, even more preferably 80 mol % or more, and still more preferably 90 mol % or more.

As the dihydroxy compound used in the polyester resin, dihydroxy compounds other than chain dihydroxy compounds and alicyclic dihydroxy compounds (also referred to as "other dihydroxy compounds") may be used within the scope of not impairing the effects of the present invention. In the polyester resin, the content of structural units derived from other dihydroxy compounds is, for example, 20 mol% or less, preferably 10 mol% or less, more preferably 5 mol% or less, and most preferably 0 mol% in 100 mol of structural units derived from dihydroxy compounds in the polyester resin.
Other dihydroxy compounds include p-xylenediol, 2,2-bis(4-hydroxyphenyl)propane (bisphenol A), tetrabromobisphenol A, tetrabromobisphenol A-bis(2-hydroxyethyl ether), α,α'-bis(4-hydroxyphenyl)-m-diisopropylbenzene (bisphenol M), 9,9-bis(4-hydroxy-3-methylphenyl)fluorene, 1,1-bis(4-hydroxyphenyl)cyclohexane, 1,1-bis(4-hydroxyphenyl)-3,3,5-trimethylcyclohexane, 4,4'-dihydroxy-3,3'-dimethyldiphenyl sulfide, 2,2-bis(4-hydroxy-3-methylphenyl)propane (bisphenol C), 2,2-bis(4-hydroxyphenyl)-1,1,1,3,3,3-hexafluoropropane (bisphenol AF), and 1,1-bis(4-hydroxyphenyl)decane.

Among the above, from the viewpoint of increasing low-temperature fusion properties and adhesive strength between films or layers, the polyester resin preferably contains structural units derived from ethylene glycol and structural units derived from cyclohexanedimethanol, and also preferably contains structural units derived from ethylene glycol, structural units derived from cyclohexanedimethanol, and structural units derived from tetramethylcyclobutanediol.

The polyester resin is preferably an amorphous polyester. By using an amorphous polyester, the adhesive strength of the resin layer (2) to another film or the resin layer (1) is likely to be good, and delamination between layers in a multilayer film or peeling from another film is unlikely to occur. The amorphous polyester may be a polyester that is substantially amorphous. As a polyester that is substantially amorphous (including low crystallinity), polyesters that do not show a clear crystalline melting peak when heated using a differential scanning calorimeter (DSC), polyesters that have crystallinity but have a slow crystallization rate and do not become highly crystalline when molded by an extrusion film forming method, and polyesters that have crystallinity and have a low crystal fusion heat (ΔHm) of 10 J/g or less when heated using a differential scanning calorimeter (DSC) can be used. In other words, the amorphous and polyester in the present invention also include "crystalline polyesters in an amorphous state".

As the amorphous polyester, a copolymer polyester mainly composed of terephthalic acid as a dicarboxylic acid component and mainly composed of 1,4-CHDM (1,4-cyclohexanedimethanol) and ethylene glycol as diol components is preferred because it provides a good balance of low-temperature fusion properties, adhesion, heat resistance, etc. sufficient for practical use, and because the raw materials are easily available. In this case, the 1,4-CHDM is 20 mol% or more and 80 mol% or less, preferably 22 mol% or more and 60 mol% or less, more preferably 25 mol% or more and 45 mol% or less, based on the total amount of the diol components, and the ethylene glycol is 20 mol% or more and 80 mol% or less, preferably 40 mol% or more and 78 mol% or less, more preferably 55 mol% or more and 75 mol% or less. Such a copolymer polyester may be referred to as PETG (glycol-modified polyethylene terephthalate) in this specification.
Here, the term "mainly" in the dicarboxylic acid component means that the total amount of the dicarboxylic acid component is taken as 100 mol % and that terephthalic acid accounts for 70 mol % or more, preferably 80 mol % or more, and more preferably 98 mol % or more. Also, the term "mainly" in the diol component means that the total amount of 1,4-CHDM and ethylene glycol accounts for preferably 70 mol % or more, more preferably 80 mol % or more, and even more preferably 90 mol % or more of the total amount of the diol component.
By having the amount of 1,4-CHDM in the diol component be equal to or more than the lower limit, the characteristics of the crystalline resin are suppressed, the decrease in transparency due to crystallization is easily suppressed, and the adhesiveness to other layers is easily improved. On the other hand, by having the amount of 1,4-CHDM be equal to or less than the upper limit, the characteristics of the crystalline resin are similarly suppressed, the decrease in transparency due to crystallization is easily suppressed, and the adhesiveness to other resin layers or films is easily improved, which is preferable.

Among the copolymer polyesters in the above composition range, those in which 1,4-CHDM is about 30 mol % of the diol component are known to show no crystallization behavior even in DSC (differential scanning calorimetry) measurements and to be completely amorphous. An example of a completely amorphous polyester is PETG such as "Easter GN001" manufactured by Eastman Chemical Company.
However, the polyester resins are not limited thereto, and may be copolymer polyester resins having a structure in which crystallization is inhibited by the introduction of various copolymer components, such as low-crystalline PET resins copolymerized with diethylene glycol, low-crystalline PET resins or PBT resins copolymerized with isophthalic acid, etc. In addition, polyester resins in which part or all of the terephthalic acid is replaced with naphthalenedicarboxylic acid among these polyester resins exemplified above can be used similarly as long as they are amorphous.

In the resin composition (2), the polyester resin may be used alone or in combination of two or more kinds. When two or more kinds are used in combination, for example, the resin composition (2) may use a combination of an amorphous polyester and a crystalline polyester, or may use a combination of PETG and a polyester resin other than PETG.

In the resin composition (2), it is preferable that the main component is a polyester resin. In the resin composition (2), it is preferable that the main component is an amorphous polyester, and among them, it is particularly preferable that the main component is PETG.
Here, being a main component means being a component with the largest content in the resin composition (2), and specifically, it is preferably 50% by mass or more in the resin composition (2), more preferably 60% by mass or more, even more preferably 70% by mass or more, and even more preferably 75% by mass or more. When the proportion of the polyester resin or the like in the resin composition (2) is higher than 50% by mass or more, it becomes easier to increase the low-temperature fusion property and the adhesive strength to another film or resin layer (1).
On the other hand, the proportion of the polyester resin or the like in the resin composition (2) may be 100% by mass or less in the resin composition (2). From the viewpoint of easily incorporating a certain amount or more of other components, the proportion is preferably 97% by mass or less, more preferably 95% by mass or less, and even more preferably 92% by mass or less.

(Filling material)
The resin composition (2) preferably contains a filler. By containing the filler, the resin composition (2) has low light transmittance and can exhibit, for example, concealment properties. Therefore, the present film can be suitably used for cards and passports, and can be suitably used for core sheets in particular.
Furthermore, if the resin layer (1) containing the above-mentioned polycarbonate resin (A) contains a filler such as titanium oxide, yellowing may occur when used under high temperature and high humidity environments, but by hiding the resin layer (1) with the resin layer (2), the yellowing of the resin layer (1) can be made less noticeable by the resin layer (2). Furthermore, since this yellowing becomes less noticeable when the resin composition (2) contains a filler, it is preferable that the resin composition (2) contains a filler.
Therefore, it is preferable that both of the resin layers (1) and (2) contain a filler. In particular, when the resin layer (2) is provided on both sides of the resin layer (1) as described later, the resin layer (1) is covered from both surface sides with the resin layer (2), so that the yellowing caused in the resin layer (1) can be made even less noticeable.

Specific examples of the filler used in the resin composition (2) can be appropriately selected from those listed as fillers usable in the resin composition (1), and among them, at least one selected from fillers having a refractive index of 2 or more is preferable, and the refractive index is more preferably 2.2 or more, and even more preferably 2.4 or more. Examples of fillers having a refractive index of 2 or more are as described above. By containing a filler having a refractive index of 2 or more in the resin composition (2), the hiding power is increased, the resin composition (2) is easily colored white, and the yellowing caused in the resin layer (1) can be made less noticeable. From these viewpoints, titanium oxide is more preferable as the filler used in the resin composition (2). Examples of titanium oxide include, but are not limited to, rutile type titanium oxide and anatase type titanium oxide. The refractive index of the filler can be measured by the Becke line method. That is, it is particularly preferable that both of the resin compositions (1) and (2) contain titanium oxide as a filler.
The average particle size of the filler used in the resin composition (2) is not particularly limited, and may be appropriately selected from the above-mentioned range, similar to the filler used in the resin composition (1).

The content of the filler in the resin composition (2) is preferably 3 parts by mass or more and 70 parts by mass or less with respect to 100 parts by mass of the resin component contained in the resin composition (2). By making the content of the filler 3 parts by mass or more, the concealing property of the present film can be improved. In addition, even if yellowing occurs in the resin layer (1), it is easy to make the yellowing less noticeable by covering it with the resin layer (2).
On the other hand, by setting the content of the filler in the resin composition (2) to 70 parts by mass or less, it becomes easier to maintain good mechanical properties such as bending resistance. Furthermore, even if titanium oxide or the like is blended, it becomes easier to suppress the occurrence of yellowing in the resin layer (2) itself. From these viewpoints, the content of the filler in the resin composition (2) is more preferably 5 parts by mass or more, even more preferably 8 parts by mass or more, and even more preferably 10 parts by mass or more. In addition, the content of the filler is more preferably 60 parts by mass or less, even more preferably 55 parts by mass or less, even more preferably 50 parts by mass or less, even more preferably 45 parts by mass or less, and even more preferably 40 parts by mass or less.

The resin composition (2) may contain components other than the resin components such as polyester resin and the filler that is blended as necessary, for example, additives other than these (also referred to as other additives). Specific examples of other additives are as described in the resin composition (1), and in the resin composition (2), the other additives may be used alone or in combination of two or more kinds.

[film]
As described above, the present film may be a single-layer film consisting of a single resin layer (1), or may be a multilayer film having two or more resin layers. The number of layers of the multilayer film is not particularly limited as long as it has two or more resin layers. The multilayer film may have at least one resin layer (1), but may have two or more resin layers (1).
In addition, the present film preferably has a resin layer (1) made of the above-mentioned resin composition (1) and a resin layer (2) made of the resin composition (2). In this case, the film may have two or more resin layers (1) or two or more resin layers (2), but it is preferable that the film has at least two or more resin layers (2).
In addition, when two or more resin layers (1) are provided, the compositions of the resin compositions (1) constituting each resin layer (1) may be the same as or different from each other. Similarly, when two or more resin layers (2) are provided, the compositions of the resin compositions (2) constituting each resin layer (2) may be the same as or different from each other.

In the case of a multilayer film, the present film preferably has resin layer (1) and resin layer (2) as described above, and is preferably laminated so that resin layer (1) is in contact with resin layer (2). By having the above-mentioned composition, resin layer (1) and resin layer (2) laminated so as to be in contact with each other can be bonded with high adhesive strength, and delamination between resin layer (1) and resin layer (2) is unlikely to occur.

In the case of a multilayer film, it is preferable that at least one resin layer (2) is disposed closer to the surface side of the present film than the resin layer (1). By disposing the resin layer (2) closer to the surface side than the resin layer (1), the resin layer (1) can be covered with the resin layer (2). In other words, when the multilayer film has a two-layer structure, it is preferable that the multilayer film has a laminate structure of the resin layer (2)/resin layer (1).
In the case where the resin layer (1) contains a filler such as titanium oxide, by covering the resin layer (1) with the resin layer (2), particularly by containing a filler such as titanium oxide in the resin layer (2), even if the resin layer (1) yellows due to the titanium oxide or the like, the yellowing can be hidden by the resin layer (2), and the yellowing of the entire film can also be suppressed.
The resin layer (2) disposed on the surface side may preferably be a surface layer constituting the surface of the present film, which makes it easier to improve the adhesive strength to another film.

It is also preferred that the multilayer film has a resin layer (1) as a middle layer, and a resin layer (2) is disposed on each of both sides of the middle layer. In this case, each resin layer (2) is preferably a surface layer constituting the surface of the present film.
That is, when the multilayer film has a three-layer structure, it preferably has a laminate structure of resin layer (2)/resin layer (1)/resin layer (2).
In the three-layer structure, as described above, it is preferable that both the resin layer (1) and the resin layer (2) contain a filler such as titanium oxide. Since the present film has the resin layer (2) on both sides of the resin layer (1), even if the resin layer (1) contains a filler such as titanium oxide and is yellowed by the filler, the yellowing can be hidden from both sides by the resin layer (2), and the yellowing of the entire film can be further suppressed.

The multilayer film is not limited to the layer structure described above and may have any structure. For example, when the film has multiple resin layers (1) or multiple resin layers (2), the layer structure is not limited to the two-layer or three-layer structure described above and may have a layer structure such as resin layer (1)/resin layer (1)/resin layer (2) or resin layer (2)/resin layer (1)/resin layer (1). The multilayer film may also have a layer structure in which four or more resin layers are stacked.

The thickness of the present film is not particularly limited and may be adjusted appropriately depending on the purpose of use, but is, for example, 5 μm or more, preferably 10 μm or more, more preferably 15 μm or more, even more preferably 20 μm or more, and even more preferably 40 μm or more, and is, for example, 1000 μm or less, preferably 500 μm or less, more preferably 300 μm or less, even more preferably 250 μm or less, and even more preferably 200 μm or less. By making the thickness of the present film at a certain level or more, the present film is more likely to exhibit its appropriate function. For example, when a filler is contained, it is easier to ensure concealment. On the other hand, by making the thickness below a certain level, it is easier to make cards and passports thinner.

The thickness of the resin layer (1) is not particularly limited and may be appropriately adjusted depending on the purpose of use, but is, for example, 5 μm or more, preferably 10 μm or more, more preferably 15 μm or more, and even more preferably 20 μm or more. Also, for example, it is 800 μm or less, preferably 400 μm or less, more preferably 300 μm or less, even more preferably 200 μm or less, and even more preferably 150 μm or less. By making the thickness of the resin layer (1) a certain level or more, the resin layer (1) is more likely to exhibit an appropriate function, and for example, when a filler is contained, it is easier to ensure concealment. In addition, by increasing the thickness of the resin layer (1) and reducing the thickness of the other resin layers, it is easier to reduce the environmental load. On the other hand, by making the thickness below a certain level, it is easier to make cards and passports thinner.
The thickness of the resin layer (1) referred to here means the thickness of each resin layer (1) when two or more resin layers (1) are provided in the film. The same applies to the thickness of the resin layer (2) described below.

In addition, by increasing the ratio (thickness ratio) of the thickness of the resin layer (1) to the thickness of the entire film, the amount of biomass-derived components can be increased. Therefore, it is preferable that the thickness ratio is a certain level or higher. Specifically, it is preferably 0.1 or higher, more preferably 0.2 or higher, even more preferably 0.3 or higher, and even more preferably 0.4 or higher. The thickness ratio may be 1 or lower, but in the case of having a resin layer (2), it is preferable that the thickness of the resin layer (2) is a certain level or higher, and is, for example, 0.9 or lower, preferably 0.8 or lower, and more preferably 0.7 or lower. The thickness ratio is the ratio of the total thickness of all resin layers (1) contained in the film to the thickness of the entire film.

In addition, the thickness of the resin layer (2) in the multilayer film is not particularly limited and may be adjusted appropriately depending on the purpose of use, but is, for example, 3 μm or more, preferably 5 μm or more, more preferably 10 μm or more, and even more preferably 15 μm or more. Also, for example, it is 500 μm or less, preferably 300 μm or less, more preferably 200 μm or less, even more preferably 150 μm or less, and even more preferably 100 μm or less. By making the thickness of the resin layer (2) a certain level or more, the resin layer (2) can easily perform an appropriate function, and for example, when a filler is contained, it is easy to ensure concealment and to make the yellowing of the resin layer (1) less noticeable. Furthermore, by having a certain level or more of thickness, when it is placed on the surface layer, it is easy to improve the adhesive strength to another film. On the other hand, by making the thickness a certain level or less, it is easy to make cards and passports thinner, and it is easy to increase the thickness ratio of the resin layer (1), which makes it easy to reduce the environmental load.

The color difference ΔE between before and after the film is subjected to a 7-day moist heat treatment under conditions of 60° C. and 90% RH is preferably small. A small color difference ΔE means that there is little color change even after moist heat treatment and that the film has high moist heat resistance. ΔE is preferably 1.4 or less, more preferably 1.0 or less, even more preferably 0.75 or less, and even more preferably 0.5 or less. The smaller ΔE is, the better, and it is sufficient that it is 0 or more.
In addition, the present film is preferably small in difference Δb* (absolute value) between b* before and after moist heat treatment under conditions of 60°C and 90% RH for 7 days. A small absolute value of difference Δb* means that there is little color change even after moist heat treatment and that moist heat resistance is high. Δb* (absolute value) is preferably 1.4 or less, more preferably 1.0 or less, even more preferably 0.75 or less, and even more preferably 0.5 or less. The smaller Δb* (absolute value) is, the better, and it is sufficient that it is 0 or more. The detailed measurement conditions of ΔE and Δb* are preferably as described in the examples.

(Manufacturing method of the present film)
This film can be manufactured by a known method, but first, each resin composition is prepared from the raw materials for forming each resin layer. Here, the raw materials are preferably mixed to form a resin composition, and may be melt-kneaded while heating in an extruder, a plastomill, or the like. In the case of a single-layer film, the prepared resin composition (1) may be made into a film. The method for making the resin composition (1) into a film is not particularly limited, and may be press molding or extrusion molding, but extrusion molding is preferred from the standpoint of productivity and cost.

In the case of a multilayer film, the method of producing the present film may be, for example, a method of laminating resin compositions for forming each resin layer by coextrusion to a desired thickness (coextrusion method), a method of forming each layer into a film having a desired thickness and laminating this, or a method of forming one or more layers by melt extrusion and laminating this onto a separately formed film, etc. Among these, production by the coextrusion method is preferred from the standpoint of productivity and cost.
In extrusion molding such as coextrusion, the resin composition may be heated and melted, and extruded from a T-die at a temperature in the range of, for example, 200 to 300° C. The extruded film may be cooled and solidified with a cooling roll (casting roll) or the like.

[Laminate]
The present film is preferably used by being laminated to another film. When laminated to another film, the resulting laminate (hereinafter also referred to as the present laminate) comprises the present film and the other film laminated with the present film. The present film and the other film are preferably bonded to each other by heat fusion, as described below.

As described above, the present film may be a single layer film or a multilayer film. In the case of a multilayer film, however, it is preferable that the resin layer (2) is disposed as a surface layer on the surface facing the other film (more specifically, the surface that comes into contact with the other film). When the resin layer (2) is disposed as a surface layer on the surface facing the other film, the adhesive strength of the present film to the other film is easily improved even when fusion is performed at a relatively low temperature, and peeling between the films is less likely to occur.

The other film is preferably a resin film containing a resin component other than a polycarbonate resin. Specifically, the other film can be appropriately selected from the resins listed as the other resin components in the resin layer (1) described above. Among them, polyester resins and polyvinyl chloride resins are preferred, and polyester resins are even more preferred.
The detailed description of the polyester resin and the polyvinyl chloride resin is the same as that of the polyester resin and the polyvinyl chloride resin in the resin composition (2), and the description thereof will be omitted. Therefore, the polyester resin is preferably an amorphous polyester such as PETG. By including an amorphous polyester in the other film, the present film and the other film can be fused with high adhesive strength by heat fusion at a relatively low temperature, and peeling between the present film and the other film is unlikely to occur. In addition, as described above, the polyvinyl chloride resin is preferably a hard polyvinyl chloride resin.

The other film is preferably formed from a resin composition (3) containing a resin component other than the polycarbonate resin described above. The resin components used in the resin composition (3) are as described above, and one or more of the resin components listed above may be appropriately selected and used. The other film is preferably formed from a resin composition (3) containing at least a polyester resin or a polyvinyl chloride resin among the above. However, the resin composition (3) may contain a polycarbonate resin in addition to the resin components other than the polycarbonate resin, as long as the effects of the present invention are achieved. The polycarbonate resin may be the polycarbonate resin (A) described above or the polycarbonate resin (B). However, the resin component of the other film (3) may be a polycarbonate resin.

The resin composition (3) is preferably mainly composed of a polyester resin or a polyvinyl chloride resin. In addition, when the resin composition (3) is mainly composed of a polyester resin, it is more preferable that the main component is an amorphous polyester, and among these, it is particularly preferable that the main component is PETG.
Here, being a main component means being a component with the largest content in the resin composition (3), and specifically, the proportion of the component is preferably 50 mass% or more in the resin composition (3), more preferably 60 mass% or more, even more preferably 70 mass% or more, and even more preferably 75 mass% or more. When the proportion of the polyester resin, polyvinyl chloride resin, or the like in the resin composition (3) is higher than 50 mass% or more, the adhesion of the present film to another film is easily increased, and peeling between the present film and another film is less likely to occur.
On the other hand, the proportion of the polyester resin, polyvinyl chloride resin, or the like in the resin composition (3) may be 100 mass% or less in the resin composition (3). From the viewpoint of making it easier to include a certain amount or more of other components, however, it may be 99 mass% or less, 97 mass% or less, or 95 mass% or less.

In addition to the above-mentioned resin components, the resin composition (3) may contain fillers, metal stabilizers, etc. as appropriate, and may also contain other additives (also referred to as other additives). Details of the fillers, metal stabilizers, and other additives are as described above in the resin composition (1).

The separate film laminated to the present film may be a single-layer film consisting of a single resin layer, or may be a multi-layer film consisting of multiple resin layers, but it is preferable that at least the surface facing the present film (i.e., the surface in contact with the present film) has a resin layer consisting of the above-mentioned resin composition (3).

The thickness of the other film is not particularly limited and may be adjusted appropriately depending on the purpose of use, but is, for example, 5 μm or more, preferably 10 μm or more, more preferably 15 μm or more, even more preferably 20 μm or more, and even more preferably 40 μm or more, and is, for example, 1000 μm or less, preferably 500 μm or less, more preferably 300 μm or less, even more preferably 250 μm or less, and even more preferably 200 μm or less. By making the thickness of the other film at a certain level or more, the other film is more likely to perform its appropriate function. On the other hand, by making the thickness below a certain level, it is easier to make the card or passport thinner.

The present film may be laminated to another film by a known method, but is preferably laminated to another film by heat fusion, and more preferably by heat pressing. As described below, when the present film is used in a card or passport, it is generally heat fused to another film by heat pressing, so the present laminate obtained by heat fusion of the present film and another film can be suitably used in a card or passport.
The temperature during heat fusion is not particularly limited, but from the viewpoint of achieving good workability by fusion at a low temperature, it is preferably 165° C. or lower, more preferably 150° C. or lower, even more preferably 145° C. or lower, even more preferably 140° C. or lower, and even more preferably 135° C. or lower. In addition, from the viewpoint of increasing the adhesive strength between the films, the temperature during heat fusion is preferably 100° C. or higher, more preferably 110° C. or higher, even more preferably 115° C. or higher, and even more preferably 120° C. or higher.

[Card or passport]
The present film is preferably used in a card or passport, in which the present film is preferably laminated to another film as described above and used as a laminate.
The present film can be laminated on another film without peeling even when heat-sealed at a relatively low temperature, and therefore can be suitably used in cards or passports that are generally constructed by laminating a plurality of films. The present film is particularly preferably used as a core sheet for cards or passports. However, the present film or the present laminate may be used for purposes other than cards or passports.

The film or laminate can be used for a variety of cards, including IC cards, magnetic cards, driver's licenses, residence cards, qualification certificates, employee ID cards, student ID cards, insurance cards, My Number cards, seal registration certificates, vehicle inspection certificates, tag cards, prepaid cards, cash cards, bank cards, credit cards, SIM cards, ETC cards, identification cards, information carrying cards, smart cards, B-CAS cards, and memory cards. It is recommended that this film or laminate be used for the data pages of passports.

The card or passport of the present invention (more specifically, the data page of the passport) may include the above-mentioned present film. The card or passport is usually composed of a plurality of resin films, at least one of which may be the present film.
The card or passport may include a core sheet. In addition to the core sheet, the card or passport may include at least one of a laser marking sheet and an oversheet.
The passport or card may be produced by stacking a plurality of resin films, for example, one or more sheets selected from a core sheet and a sheet other than the core sheet, pressing and heat fusing the sheets, and then performing a punching process, etc. Alternatively, the sheets may be bonded together using an appropriate adhesive, etc., instead of heat fusing.

It is also preferable that the card or passport comprises the laminate described above. That is, the card or passport is constructed by laminating a plurality of resin films as described above, and it is preferable that some or all of the laminate is constructed by laminating the present film with another film.

For example, as shown in Fig. 1(a), the card is preferably a card 20A comprising a laser marking sheet 1 and a core sheet 2, with the laser marking sheet 1 on one or both surfaces of the core sheet 2. As shown in Fig. 1(b), the card is also preferably a card 20B further comprising an oversheet 4, with the oversheet 4 further laminated as a protective layer on the outside of the laser marking sheet 1. The laser marking sheet may be omitted, and the card may be, for example, a card 20C comprising a core sheet 2 and an oversheet 4 as a protective layer on one or both surfaces of the core sheet 2, as shown in Fig. 1(c).
Although Figure 1 shows an embodiment in which a laser marking sheet 1, an over sheet 4, or both of these are provided on both sides of the core sheet 2, a laser marking sheet 1, an over sheet 4, or both of these may be provided on only one side of the core sheet 2.
In addition, in each of the cards 20A to 20C, the layer structures provided on both sides of the core sheet 2 are the same, but they may be different on each side. For example, the laser marking sheet 1 and the oversheet 4 may be provided in this order on one side of the core sheet 2, and only the oversheet 4 may be provided on the other side of the core sheet 2.

The passport, particularly in the case of an electronic passport, may include a hinge sheet. For example, as shown in FIG. 2(a), a passport 10A is preferably provided with a hinge sheet 3 and a core sheet 2 provided on each side of the hinge sheet 3, with a laser marking sheet 1 laminated on one or both of the outer sides of the core sheet 2. As shown in FIG. 2(b), a passport 10B is also preferable, which includes an oversheet 4 and further includes an oversheet 4 laminated on the outer side of the laser marking sheet 1 as a protective layer. The laser marking sheet may be omitted, and the passport may be a passport 10C as shown in FIG. 2(c), which includes a hinge sheet 3, a core sheet 2 provided on each side of the hinge sheet 3, and an oversheet 4 as a protective layer on one or both of the outer sides of the core sheet 2.

In addition, while Figure 2 shows an embodiment in which a laser marking sheet 1, an over sheet 4, or both are provided on either outer side of the core sheet 2, a laser marking sheet 1, an over sheet 4, or both may be provided on only one of the outer sides of the core sheet 2.
In each of the passports 10A to 10C, the layer structures provided on the outer sides of the core sheet 2 are the same, but they may be different from each other. For example, the laser marking sheet 1 and the oversheet 4 may be provided in this order on one outer side of the core sheet 2, and only the oversheet 4 may be provided on the other outer side of the core sheet 2.

2(a) to 2(c) show a mode in which the core sheets 2, 2 are arranged to sandwich the hinge sheet 3, but this is not particularly limited, and the core sheets do not need to be arranged to sandwich the hinge sheet, and there may be only one core sheet. Also, the core sheet may be formed by stacking multiple core sheets without sandwiching a hinge sheet. Also, the hinge sheet 3 does not need to be in contact with the core sheet, and may be arranged in any position that is not in contact with the core sheet.
Instead of being between the core sheets, the hinge sheet may be disposed, for example, but not limited to, between the core sheet and the over sheet, between the core sheet and the laser marking sheet, between the laser marking sheet and the over sheet, etc.

In the card or passport, the core sheet is preferably a resin film containing the above-mentioned resin components appropriately, and preferably contains a filler. The core sheet may be a laminate of a plurality of core sheets. The thickness of each core sheet is preferably about 50 to 700 μm.
Each core sheet may be a printing sheet on which fixed information is printed, an inlet sheet having a hollow portion for accommodating an inlet such as an IC chip or an antenna, or a concealment sheet for concealing an inlet.
Furthermore, an adhesive sheet or the like may be appropriately placed between a pair of adjacent core sheets, and the pair of adjacent core sheets may be bonded together by the adhesive sheet. Each core sheet may be made of a single-layer film or a multi-layer film having two or more resin layers. The adhesive sheet may be provided between the core sheet and the oversheet or the laser marking sheet.

The laser marking sheet may be a resin film containing the above-mentioned resin components. The laser marking sheet is a sheet on which personal information, etc. is printed by laser printing. The personal information is information for identifying the individual of the passport or card holder, such as the individual's name, personal ID, card number, etc.
The laser marking sheet may be formed from a resin film, and the resin film may be a single-layer film or a multi-layer film having two or more resin layers. The laser marking sheet preferably includes a resin layer containing a laser coloring agent, and in the case of a single-layer film, the single-layer resin layer may contain a laser coloring agent. In the case of a multi-layer film, the laser marking sheet may have a structure in which a surface layer is provided on both sides of a middle layer, and the middle layer may contain a laser coloring agent. The laser marking sheet is typically a transparent film. The thickness of the laser marking sheet is not particularly limited, but is, for example, about 5 to 400 μm, and preferably 10 to 300 μm.

An oversheet generally constitutes the outermost layer of the data page of a card or passport, and protects the card or passport. When the oversheet is placed on the outside of the laser marking sheet as shown in Figures 1(b) and 2(b), it can, for example, suppress the so-called "blistering" that occurs when the laser-printed portion foams due to irradiation with laser light. There are no particular restrictions on the resin used for the oversheet, and it is advisable to appropriately select and use the resin components described above. There are no particular restrictions on the thickness of the oversheet, but it is, for example, about 5 to 400 μm, and preferably 10 to 300 μm.

The hinge sheet in a passport is a sheet that serves to firmly bind the data page together with the cover of the passport and other visa sheets. Any known hinge sheet can be used, and it may be a resin sheet made of a thermoplastic resin or a thermoplastic elastomer, such as a thermoplastic polyester resin, a thermoplastic polyester elastomer, a thermoplastic polyamide resin, a thermoplastic polyamide elastomer, a thermoplastic polyurethane resin, or a thermoplastic polyurethane elastomer, or it may be made of a woven fabric, knitted fabric, or nonwoven fabric, or it may be a composite material of a woven fabric, knitted fabric, or nonwoven fabric with a thermoplastic resin or a thermoplastic elastomer.

In a card or passport, the resin films used in the core sheet, the laser marking sheet, and the oversheet may be composed of the present film as described above, but as long as the card or passport has at least one of the present films, resin films other than the present film may be used. Here, it is preferable that the present film is used in at least the core sheet of the card or passport.
In addition, when the core sheet is composed of a plurality of core sheets, at least one of the plurality of core sheets may be composed of the present film, or all of the core sheets may be composed of the present film. In addition, when a plurality of laser marking sheets and a plurality of over sheets are provided, at least one of the plurality of sheets may be composed of the present film, or all of the sheets may be composed of the present film.

The following examples and comparative examples are provided, but the present invention is not limited in any way by these.

The films obtained in the examples and comparative examples were evaluated in the following manner.
(derived from biomass)
The present films obtained in each of the Examples and Comparative Examples were rated as "OK" when they contained a component derived from biomass, and as "NG" when they did not contain a component derived from biomass.

[Heat fusion with PETG]
Using an electric sealer "Impulse Sealer OPL-200-10" (manufactured by Fuji Impulse Co., Ltd.), the films obtained in each Example and Comparative Example and a PETG film of 100 μm thickness made of PETG were heat-sealed at a sheet width of 10 mm and a length of 40 mm (heat-sealed length 10 mm, unheat-sealed length 30 mm) under the conditions of heating at 130° C. for 5 seconds and then cooling at 40° C. for 5 seconds to obtain a laminated sheet (laminate). Then, a T-shaped peel test was performed by holding the unheat-sealed part by hand, and the laminated sheet was evaluated according to the following evaluation criteria. In the evaluation of heat-sealability, if the laminated sheet breaks without peeling between the layers (between the films), it means that the film and the PETG sheet are properly bonded, the adhesive strength between the films is high, and the heat-sealability is good. In addition, "breakage" is a destruction mode in which the laminated sheet is destroyed in a part other than between the layers.
A: The material broke without any interlayer peeling. B: One member of the laminated sheet broke, and some interlayer peeling occurred.
C: The laminated sheet was not broken and the layers were completely peeled off from each other.

[Heat fusion with PVC]
Using an electric sealer "Impulse Sealer OPL-200-10" (manufactured by Fuji Impulse Co., Ltd.), the films obtained in each Example and Comparative Example and a hard polyvinyl chloride resin film (manufactured by Mitsubishi Chemical Corporation, "Vinifoil C-8195", thickness 100 μm) were heat-sealed at 130° C. for 5 seconds, followed by cooling at 40° C. for 5 seconds to obtain a laminated sheet (laminate) with a sheet width of 10 mm and length of 40 mm (heat-sealed length 10 mm, unheat-sealed length 30 mm). Thereafter, a T-peel test was performed by holding the unheat-sealed portion by hand, and the evaluation was performed according to the following criteria.
A: The material broke without any interlayer peeling. B: One member of the laminated sheet broke, and some interlayer peeling occurred.
C: The laminated sheet was not broken and the layers were completely peeled off from each other.

[Delamination between surface layer and middle layer]
A part of the surface of the film (multilayer film) obtained in each Example and Comparative Example was painted with black marker, and then the film was overlaid on a PETG film having a thickness of 100 μm, and heat-sealed by heat pressing using a heat press machine "NF-37" (manufactured by Shinto Metal Industry Co., Ltd.) at 120°C x 6 minutes x surface pressure of 2 MPa, and then cooled to room temperature to obtain a laminated sheet (laminate).
The laminated sheet was cut to a width of 10 mm and a length of 40 mm, including the unfused black portion, and the unfused portion was held by hand to carry out a T-peel test, which was evaluated according to the following criteria. In the evaluation of delamination, if the laminated sheet broke without peeling between the layers (between the surface layer and the middle layer), this means that the surface layer and the middle layer are properly bonded and the adhesive strength between the layers is high. Whether or not the failure mode is delamination can be determined by visual inspection or estimated from the thickness of each layer.
A: The material broke without any interlayer peeling. B: One member of the laminated sheet broke, and some interlayer peeling occurred.
C: The laminated sheet was not broken and the layers were completely peeled off from each other.

[Heat fusion with the same film]
Using an electric sealer "Impulse Sealer OPL-200-10" (manufactured by Fuji Impulse Co., Ltd.), the films obtained in each Example and Comparative Example were heat-sealed together at a sheet width of 10 mm and length of 40 mm (heat-sealed length 10 mm, unheat-sealed length 30 mm) under the conditions of a heating time of 5 seconds and subsequent cooling at 40°C for 5 seconds. After that, a T-peel test was performed by holding the unheat-sealed portion by hand to check whether the laminated sheet broke. The heating temperature was increased in 10°C increments, and the first temperature at which the sheet broke (fracture temperature) was evaluated. The fracture temperature is the temperature at which the laminated sheet is properly fused, and the lower the fracture temperature, the better the low-temperature heat adhesion.

[Color difference before and after wet heat test (ΔE, Δb*)]
Each film obtained in each Example and Comparative Example was subjected to a moist heat treatment for 7 days under conditions of 60°C and 90% RH using a thermohygrostat "LHL-113" manufactured by Espec Corp. The chromaticity (L*a*b* color system) of the film before and after the moist heat treatment was measured using a spectrophotometer "CM-2500d" manufactured by Konica Minolta Inc., and the color difference ΔE before and after the moist heat treatment was evaluated. A smaller value of the color difference ΔE indicates a smaller color change before and after the treatment.
In addition, the b* before the moist heat treatment was subtracted from the b* after the moist heat treatment to obtain Δb*. Δb* is a measure of the color change between blue and yellow, and the smaller the absolute value, the smaller the color change. A positive value of Δb* indicates a color change toward yellow, and a negative value indicates a color change toward blue.

The raw materials used in the examples and comparative examples are as follows.
(resin)
ISP: A polycarbonate resin obtained by melt polymerization using isosorbide and 1,4-cyclohexanedimethanol as dihydroxy compounds such that the ratio of structural units derived from isosorbide to structural units derived from 1,4-cyclohexanedimethanol is 50:50 (mol%). Deflection temperature under load (JIS K7191-2:2015 A method, 1.80 MPa): 82°C
PC1: bisphenol A homopolycarbonate (interfacial polymerization method), Mw: 72,000, Mn: 23,900, Mw/Mn: 3.0, melt volume rate (300°C, 1.2 kgf): 4 cm ³ /10 min, deflection temperature under load (JIS K7191-2:2015 A method, 1.80 MPa): 130°C
PC2: bisphenol A homopolycarbonate (melt polymerization method), Mw: 72,300, Mn: 31,800, Mw/Mn: 2.28, melt volume rate (300°C, 1.2 kgf): 4 cm ³ /10 min, deflection temperature under load (JIS K7191-2:2015 A method, 1.80 MPa): 131°C
PETG: non-crystalline aromatic polyester resin (polyester resin in which 30 mol% of ethylene glycol in polyethylene terephthalate is replaced with 1-4-cyclohexanedimethanol), deflection temperature under load (ASTM D648 A method, 1.82 MPa): 64°C
Titanium oxide: rutile type, refractive index 2.7

[Example 1]
Using an extruder, resin composition (1) obtained by kneading PC2, ISP, and titanium oxide in the ratio shown in Table 1 was extruded from a two-kind, three-layer multi-manifold die at 230° C. as a middle layer. Also, resin composition (2) obtained by kneading PETG and titanium oxide in the ratio shown in Table 1 was extruded from the die at 230° C. as both surface layers. The extruded film was cooled with a casting roll at about 80° C. to obtain a multilayer film (present film) consisting of resin layer (2)/resin layer (1)/resin layer (2) with a thickness ratio of 1/2/1 (surface layer/middle layer/surface layer) and a total thickness of 100 μm.

[Examples 2 and 3]
The same procedure as in Example 1 was carried out, except that the compositions of the middle layer and surface layer were changed as shown in Table 1.

[Comparative Example 1]
The same procedure as in Example 1 was repeated, except that the compositions of the middle layer and the surface layer were changed as shown in Table 1, the middle layer was extruded at 240°C, and cooled with a casting roll at about 95°C.

[Comparative Example 2]
The same procedure as in Example 1 was carried out except that the compositions of the middle layer and surface layer were changed as shown in Table 1, the layers were cooled with a casting roll at about 77° C., and the total thickness was 50 μm.

[Comparative Example 3]
The same procedure as in Example 1 was repeated, except that the compositions of the middle layer and the surface layer were changed as shown in Table 1, and cooling was performed with a casting roll at about 77°C.

[Comparative Example 4]
The same procedure as in Example 1 was repeated, except that the compositions of the middle layer and the surface layer were changed as shown in Table 1, the middle layer was extruded at 260°C, both surface layers were extruded at 235°C, and cooled with a casting roll at about 90°C, and the thickness ratio was 1/4/1.

[Comparative Examples 5 and 6]
Using an extruder, the resin composition obtained by kneading the composition shown in Table 1 was extruded at 230°C, and the extruded film was cooled with a casting roll at about 95°C to obtain a monolayer film.

As shown in Table 1 above, in Examples 1 to 3, by using a resin layer (1) containing both polycarbonate resin (A) and polycarbonate resin (B) as the middle layer, the adhesive strength to resin components other than polycarbonate resin, such as PETG and PVC, was good. Therefore, even in a multilayer film in which the surface layer (resin layer (2)) is a PETG film, no delamination occurred between the resin layer (1) and the resin layer (2). Furthermore, the present films obtained in Examples 1 to 3 were excellent in low-temperature fusion properties, and could be fused with high adhesive strength to other films, such as a PETG film having a resin component other than polycarbonate resin and a PVC film.
In contrast, the films of Comparative Examples 2 to 6 did not have the resin layer (1) containing both the polycarbonate resin (A) and the polycarbonate resin (B), and therefore peeling occurred between layers in the multilayer film, or peeling occurred between the multilayer film and another film when fused to the other film.
In addition, in Comparative Example 1, by forming the surface layer as a layer containing a polyester resin and a polycarbonate resin (B), it was possible to increase the adhesive strength between layers in the multilayer film and the adhesive strength when fused to another film, but it was not possible to ensure low-temperature fusion properties.

1 Laser marking sheet 2 Core sheet 3 Hinge sheet 4 Over sheet 20A, 20B, 20C Card 10A, 10B, 10C Passport

Claims (19)

A film having a resin layer (1) made of a resin composition (1) containing a polycarbonate resin (A) having a structural unit (A1) derived from a dihydroxy compound having a moiety represented by the following formula (1) as part of its structure, and a polycarbonate resin (B) other than the polycarbonate resin (A).
(However, this does not include the case where the moiety represented by the formula (1) is a part of -CH ₂ -O-H.) The film according to claim 1, wherein the proportion of the polycarbonate resin (B) in the resin composition (1) is more than 10% by mass and not more than 90% by mass. The film according to claim 1 or 2, wherein the resin composition (1) contains a filler. The film of claim 3, wherein the filler is titanium oxide. The film according to claim 1 or 2, further comprising a resin layer (2) made of a resin composition (2) containing a polyester resin. The film according to claim 5, wherein the resin composition (2) contains an amorphous polyester. The film according to claim 5, wherein the resin composition (2) contains a filler. The film according to claim 7, wherein the filler in the resin composition (2) is titanium oxide. The film according to claim 1 or 2, wherein the polycarbonate resin (A) contains 30 mol % or more of the structural unit (A1) among structural units derived from a dihydroxy compound. The film according to claim 1 or 2, wherein the polycarbonate resin (A) contains 80 mol % or less of the structural unit (A1) among the structural units derived from a dihydroxy compound. The film according to claim 1 or 2, wherein the polycarbonate resin (A) is derived from at least one dihydroxy compound selected from the group consisting of aliphatic dihydroxy compounds and alicyclic dihydroxy compounds, and further contains a structural unit (A2) which is a structural unit other than the structural unit (A1). The film according to claim 1 or 2, wherein the polycarbonate resin (B) is a bisphenol-based polycarbonate. The film according to claim 1 or 2, which is for a card or passport. A laminate comprising the film of claim 1 and another film laminated to the film. The laminate according to claim 14, wherein the other film comprises a resin selected from the group consisting of polyester resins and polyvinyl chloride resins. The laminate of claim 14, wherein the other film comprises an amorphous polyester. A method for producing a laminate, comprising laminating the film according to claim 1 or 2 onto another film to obtain a laminate. A card having the film according to claim 1 or 2 or the laminate according to any one of claims 14 to 16. A passport having the film according to claim 1 or 2 or the laminate according to any one of claims 14 to 16.