JP7739838B2 - Film for cards or passports, inlet sheets, cards and passports - Google Patents

Description

The present invention relates to a film for cards or passports, an inlet sheet having the film, a card, and a passport.

In a passport, the data page on which personal information, photographs, etc. are written is generally made up of multiple layers of film stacked on top of each other. Writing is done on the data page using laser printing, for example, and security features may be added, such as special printing using lenticular or hologram printing. Similarly, cards are made up of multiple layers of film stacked on top of each other, and writing is done on the data page using laser printing, and security features may be added, such as special printing.

Passport data pages and cards are broadly divided into a transparent layer and a colored layer made of white or other materials, and security features and laser printing are generally performed on the transparent layer. The colored layer, on the other hand, is also known as the core sheet, and contains inlets such as IC chips. Therefore, the core sheet is required to properly hold inlets such as IC chips, while also concealing them.

It is known that core sheets are formed from thermoplastic resin compositions containing thermoplastic resins such as polyester resin, polycarbonate resin, or mixtures thereof. It is also known that thermoplastic resin compositions are blended with additives such as titanium oxide, inorganic fillers such as talc, mica, and calcium carbonate, and rubber-like elastomers (see, for example, Patent Document 1). By blending titanium oxide and inorganic fillers into the core sheet, it is endowed with concealing properties that enable it to conceal inlets such as IC chips.

Japanese Patent Application Laid-Open No. 2009-262557

In recent years, high security has been required for passports and cards, and the amount of information written on them has been increasing year by year. As a result, there is a demand for thicker transparent layers, while there is a need to maintain the thickness of the data page or card itself. As a result, studies are being conducted to thicken the transparent layer and reduce the thickness of the colored layer, such as the core sheet, by the same amount. However, if the colored layer, such as the core sheet, is made thinner, the concealment of the inlet may be insufficient.

In addition, while it is possible to increase the amount of filler such as titanium oxide to improve hiding power, simply increasing the amount of filler reduces bending resistance and also leads to problems such as reduced processability, such as making it difficult to embed IC chips.

Furthermore, printing of personal information and the like is often performed on laser marking sheets formed from a transparent layer and containing a laser coloring agent, but laser marking properties are sometimes insufficient, and improvements in laser marking performance are required.

The present invention aims to provide a film for cards or passports that improves the concealment of inlets such as IC chips and the printability on laser marking sheets, while also providing good bending resistance and processability.

After extensive research, the inventors discovered that by incorporating a certain amount or more of a filler such as titanium oxide into a film for forming a core sheet or the like, the concealment of the inlet is improved, and surprisingly, the laser marking performance of the laser marking sheet when laminated to the laser marking sheet is also improved. Furthermore, as a result of further research, they also discovered that by further incorporating an impact modifier into the film, bending resistance and processability can be improved, leading to the completion of the present invention described below. Specifically, the present invention provides the following [1] to [12].

[1] A card or passport film containing a resin, a filler, and an impact resistance improver, wherein the filler content is greater than 25.5% by mass.
[2] The film for cards or passports described in [1] above, wherein the content of the impact resistance improver is 1% by mass or more and 30% by mass or less.
[3] The card or passport film according to [1] or [2] above, further comprising at least one additive (X) selected from the group consisting of antioxidants and heat stabilizers, wherein the content of the additive (X) is 0.01% by mass or more and 3% by mass or less.
[4] The card or passport film according to any one of [1] to [3] above, wherein the refractive index of the filler is 2 or more.
[5] The card or passport film according to any one of [1] to [4] above, wherein the filler contains titanium oxide.
[6] The card or passport film according to any one of [1] to [5] above, wherein the resin is at least one selected from the group consisting of polycarbonate resins and polyester resins.
[7] A middle layer containing the resin and the filler, and two surface layers provided on both sides of the middle layer,
The card or passport film according to any one of [1] to [6] above, wherein each of the surface layers contains the resin, the filler, and the impact resistance improver.
[8] The card or passport film according to any one of [1] to [7] above, which is used as a core sheet.
[9] An inlet sheet comprising the card or passport film described in any one of [1] to [8] above.
[10] The inlet sheet according to the above [9], having a thickness of 100 μm or more and 500 μm or less.
[11] A card comprising any one of the above items [1] to [8] and a card or passport film, or the inlet sheet according to the above item [9] or [10].
[12] A passport comprising any one of the above items [1] to [8], a card or passport film, or the inlet sheet according to the above item [9] or [10].

The present invention provides a film for cards or passports that improves the concealment of inlets such as IC chips and the printability on laser marking sheets, while also providing good bending resistance and processability.

FIG. 2 is a schematic cross-sectional view showing an example of an IC sheet.

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. Furthermore, the terms "film" and "sheet" used in the following description are not clearly distinguished from each other, and the term "film" is intended to include "sheet," and the term "sheet" is intended to include "film."

<Card or passport film>
The card or passport film of the present invention (hereinafter sometimes simply referred to as "the film") contains a resin, a filler, and an impact resistance improver.

[resin]
The resin usable in the present invention is preferably a thermoplastic resin, which makes it possible to easily obtain a core sheet for forming a card or passport by hot pressing multiple resin films including the present film together.
Specific examples of the resin used include polycarbonate resin, polyester resin, polyolefin resin, acrylic resin, polystyrene resin, polyamide resin, polyvinyl chloride resin, polyvinylidene chloride resin, polyvinyl alcohol resin, ethylene-vinyl alcohol resin, polycycloolefin resin, ethylene-vinyl acetate copolymer resin, ethylene (meth)acrylate copolymer resin, polyphenylene ether resin, polyacetal resin, acrylonitrile-butadiene-styrene copolymer resin, polyaryletherketone resin, polyimide resin, polyphenylene sulfide resin, polyarylate resin, polysulfone resin, polyethersulfone resin, and fluororesin.
These resins may be used alone or in combination of two or more. Among these, from the viewpoints of durability and processability, it is preferable to use either a polycarbonate resin or a polyester resin, and among these, it is more preferable to use a polycarbonate resin from the viewpoints of excellent impact resistance, heat resistance, etc., and good bending resistance.

(Polycarbonate resin)
The polycarbonate resin used in the present film is not particularly limited, but examples thereof include bisphenol-based polycarbonates and polycarbonate resins containing a structural unit derived from a dihydroxy compound having a moiety represented by the formula (1) described below as part of its structure. The polycarbonate resins may be used alone or in combination of two or more.
Among the above-mentioned polycarbonate resins, bisphenol-based polycarbonate is preferred. Use of bisphenol-based polycarbonate makes it easier to achieve excellent impact resistance, heat resistance, and bending resistance.

Bisphenol-based polycarbonate refers to a polycarbonate 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 bisphenol. Bisphenol-based polycarbonate may be either a homopolymer or a copolymer. Furthermore, bisphenol-based polycarbonate may 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( Examples of bisphenols include 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.

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 dihydroxy compounds, 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, bisphenol A homopolycarbonate is most preferred as the polycarbonate resin.

The bisphenol polycarbonate may be produced by any known method such as the phosgene method (also called the interfacial polymerization method), the ester exchange method, or 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 in the presence of a basic catalyst and an acidic substance that neutralizes the basic catalyst.
Specific examples of the carbonate 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, with diphenyl carbonate being particularly preferred.

As described above, the polycarbonate resin may be a polycarbonate resin containing a structural unit (hereinafter sometimes referred to as structural unit (A1)) derived from a dihydroxy compound having a moiety represented by the following formula (1) as part of its structure. Polycarbonate resins containing structural unit (A1) can be produced from plant-derived raw materials, reducing the environmental impact.

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 a compound that contains at least two hydroxyl groups and further contains the moiety of formula (1).

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-cyclohexylphenyl)fluorene, Examples of such compounds include compounds having an aromatic group on the side chain and an ether group bonded to the aromatic group on the main chain, such as 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, and 9,9-bis(4-(3-hydroxy-2,2-dimethylpropoxy)phenyl)fluorene, as well as dihydroxy compounds having a cyclic ether structure, such as dihydroxy compounds represented by the following formula (2) and spiroglycols represented by the following formula (3):

Among the above, dihydroxy compounds having a cyclic ether structure are preferred, and anhydrous sugar alcohols such as those represented by formula (2) are particularly preferred. More specifically, dihydroxy compounds represented by formula (2) include isosorbide, isomannide, and isoidet, which are stereoisomers. Furthermore, dihydroxy compounds represented by the following formula (3) 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 are each independently an alkyl group having 1 to 3 carbon atoms.

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

A polycarbonate resin containing structural unit (A1) can further contain structural units other than structural unit (A1) as structural units derived from a dihydroxy compound. For example, it preferably contains 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 structural unit (A2)).

The aliphatic dihydroxy compound used in the polycarbonate resin containing the structural unit (A1) is not particularly limited in terms of the number of carbon atoms, but preferably includes an aliphatic dihydroxy compound having approximately 2 to 12 carbon atoms, and more preferably 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. Furthermore, structural units derived from aliphatic dihydroxy compounds, such as those described in International Publication No. 2004/111106, can also be used.

The structural unit derived from an alicyclic dihydroxy compound used in the polycarbonate resin containing the structural unit (A1) preferably contains at least one of a five-membered ring structure and a six-membered ring structure, and in particular, the six-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 of such a structure, the heat resistance of the resulting polycarbonate resin 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.
Furthermore, 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 containing the structural unit (A1) is preferably 30 mol% or more, more preferably 40 mol% or more, even more preferably 45 mol% or more, and preferably 75 mol% or less, more preferably 70 mol% or less, and even more preferably 65 mol% or less, based on the structural units derived from the dihydroxy compound. By adjusting the content within this range, coloration due to the carbonate structure and coloration due to impurities contained in trace amounts due to the use of plant-based materials can be effectively suppressed. Furthermore, this tends to achieve a balance of physical properties such as appropriate moldability, mechanical strength, and heat resistance, which is difficult to achieve with polycarbonate resins composed only of the structural unit (A1).
On the other hand, the content of the structural unit (A2) in the polycarbonate resin containing the structural unit (A1), based on the structural units derived from the dihydroxy compound, is preferably 25 mol% or more, more preferably 30 mol% or more, even more preferably 35 mol% or more, and is preferably 70 mol% or less, more preferably 60 mol% or less, even more preferably 55 mol% or less.

In the polycarbonate resin containing the structural unit (A1), the structural unit derived from a dihydroxy compound preferably consists of the structural unit (A1) and the structural unit (A2), but structural units derived from other dihydroxy compounds may also be included. Specific examples include copolymerizing a small amount of an aromatic ring-containing dihydroxy compound, such as a bisphenol, such as 2,2-bis(4-hydroxyphenyl)propane (commonly known as bisphenol A). The use of an aromatic ring-containing dihydroxy compound is expected to efficiently improve heat resistance and moldability, but adding too much tends to cause problems with weather resistance, so it is best to use an amount that does not cause problems with 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.

Polycarbonate resins containing the structural unit (A1) described above can be produced by commonly used polymerization methods, including either the phosgene method or the transesterification method in which a dihydroxy compound having a moiety represented by formula (1) as part of its structure is reacted with another dihydroxy compound and a dicarbonate in the presence of a polymerization catalyst. The transesterification method is a polymerization method in which a dihydroxy compound, a dicarbonate, a basic catalyst, and an acidic substance that neutralizes the catalyst are mixed together to carry out a transesterification reaction. Specific examples of the dicarbonate are listed above, with diphenyl carbonate being preferred.

The mass average molecular weight of the polycarbonate resin is usually 10,000 or more, preferably 30,000 or more, more preferably 38,000 or more, and even more preferably 40,000 or more, in view of the balance between mechanical properties and moldability, and is usually 100,000 or less, preferably 80,000 or less. The mass average molecular weight can be measured by gel permeation chromatography (GPC) using polystyrene as a standard substance.
Furthermore, as will be described later, the polycarbonate resin preferably has a low molecular weight from the viewpoint of being able to suppress foaming without blending the additive (X). From such a viewpoint, the mass average molecular weight of the polycarbonate resin is preferably 70,000 or less, more preferably 65,000 or less, even more preferably 60,000 or less, and even more preferably 56,000 or less.
On the other hand, from the viewpoint of heat resistance such as impact resistance, dynamic bending durability, and deflection temperature under load, it is also preferable that the polycarbonate resin has a high molecular weight, and from such a viewpoint, the mass average molecular weight of the polycarbonate resin is preferably 37,000 or more, more preferably 40,000 or more, even more preferably 45,000 or more, still more preferably 50,000 or more, even more preferably 55,000 or more, still more preferably 58,000 or more, still more preferably 60,000 or more, and particularly preferably 63,000 or more.

In addition, from the viewpoint of the balance between mechanical properties and moldability, the viscosity average molecular weight of the polycarbonate resin is usually 12,000 or more, preferably 15,000 or more, more preferably 20,000 or more, even more preferably 22,000 or more, still more preferably 26,000 or more, and particularly preferably 29,000 or more, and is usually 50,000 or less, preferably 45,000 or less, more preferably 40,000 or less, and even more preferably 35,000 or less. In addition, from the viewpoint of being able to suppress foaming without blending the additive (X), the viscosity average molecular weight is preferably 33,000 or less.
The viscosity average molecular weight can be measured by determining the intrinsic viscosity ([η]) (unit: dl/g) at 20° C. using an Ubbelohde viscometer with dichloromethane as a solvent, and calculating from the Schnell viscosity formula: η=1.23×10 ⁻⁴ M ^0.83 .

From the standpoint of mechanical properties and moldability, the melt flow rate (300°C, 1.2 kgf) of the polycarbonate resin is preferably 1 g/10 min or more, more preferably 3 g/10 min or more, even more preferably 5 g/10 min or more, still more preferably 6 g/10 min or more, and preferably 50 g/10 min or less, more preferably 40 g/10 min or less, even more preferably 30 g/10 min or less, still more preferably 25 g/10 min or less, and even more preferably 20 g/10 min or less. The melt flow rate of the polycarbonate resin can be measured in accordance with ISO 1133.

The glass transition temperature of the polycarbonate resin is preferably 110°C or higher, more preferably 125°C or higher, even more preferably 135°C or higher, and still more preferably 140°C or higher, and is preferably 200°C or lower, more preferably 175°C or lower, more preferably 170°C or lower, and even more preferably 165°C or lower.
By setting the glass transition temperature to the above lower limit or higher, it becomes easier to impart appropriate heat resistance and to reduce dimensional changes during the production of cards or passports. On the other hand, by setting the glass transition temperature to the above upper limit or lower, good moldability and the like are also achieved.
The glass transition temperature can be obtained by measuring the temperature dispersion of dynamic viscoelasticity using a viscoelasticity spectrometer in accordance with JIS K7244-4:1999 at a strain of 0.07%, a frequency of 1 Hz, a heating rate of 3°C/min, and a tensile mode, and determining the temperature at the peak top of the loss modulus.

(Polyester resin)
Examples of polyester resins include polyesters obtained by polycondensation of dicarboxylic acids and dihydroxy compounds. Dicarboxylic acid derivatives such as dicarboxylic acid esters and acid halides may also be used to synthesize polyester resins. The use of polyester resins as resins improves low-temperature fusion properties, making it easier to bond the film to other films by heat fusion at relatively low temperatures. Furthermore, processability and the like are also likely to be improved.

From the viewpoint of heat resistance, it is preferable to use an aromatic dicarboxylic acid as the dicarboxylic acid used to obtain the polyester resin, and therefore it is preferable that the polyester resin 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, and 2-methyl terephthalic acid. 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 of 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 as long as it is 100 mol% or less, but 100 mol% is most preferred.

In addition to structural units derived from aromatic dicarboxylic acids, the polyester resin may also contain a small amount (usually 40 mol % or less, for example 30 mol % or less, preferably 20 mol % or less) of structural units derived from aliphatic dicarboxylic acids. There are no particular restrictions on the aliphatic dicarboxylic acids, and examples 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. 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, which tends to improve the low-temperature fusion properties of the present film.
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 is 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 the alicyclic dihydroxy compound in addition to a structural unit derived from the chain dihydroxy compound. The use of an alicyclic dihydroxy compound tends to improve heat resistance, solvent resistance, etc.
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 due to its ease of industrial availability. Furthermore, 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 from the viewpoint of bending resistance, it is preferable to use tetramethylcyclobutanediol and cyclohexanedimethanol in combination.

In the polyester resin, the proportion of structural units derived from alicyclic dihydroxy compounds, out of a total of 100 mol% of structural units derived from chain dihydroxy compounds and 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. 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. Furthermore, 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 properties are likely to be good.
In particular, from the viewpoint of heat resistance such as storage modulus and thermal expansion/contraction rate in a high-temperature environment, and solvent resistance, 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, of which the proportion 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. Furthermore, from the viewpoint of low-temperature fusion property, the proportion of 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 is preferably 65 mol% or less, more preferably 55 mol% or less, even more preferably 45 mol% or less, and still more preferably 40 mol% or less.

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 that does not impair 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% per 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.

Of the above, from the viewpoints of low-temperature fusion properties, heat resistance, solvent resistance, etc., the polyester resin preferably contains structural units derived from ethylene glycol and structural units derived from cyclohexanedimethanol, and it is also preferable for the polyester resin to contain 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. The use of an amorphous polyester tends to improve the adhesion of the film to other components, such as resin films. The amorphous polyester may be any polyester that is substantially amorphous. Substantially amorphous (including low-crystalline) polyesters include polyesters that do not exhibit a clear crystalline melting peak upon heating using a differential scanning calorimeter (DSC), polyesters that are crystalline but have a slow crystallization rate and do not become highly crystalline upon molding using methods such as extrusion film formation, and crystalline polyesters that exhibit a low heat of crystalline fusion (ΔHm) of 10 J/g or less upon heating using a differential scanning calorimeter (DSC). In other words, the terms "amorphous" and "polyester" in this invention also encompass "crystalline polyesters in an amorphous state."

As described above, the present film preferably uses a polycarbonate resin as the resin. When using a polycarbonate resin, the polycarbonate resin may be used alone or in combination with a resin other than the polycarbonate resin. As such a resin, a known resin that is generally used may be used, but it is preferable to use, for example, a polyester resin. Details of the polyester resin that is used in combination with the polycarbonate resin are as described above.
The resin constituting the present film preferably contains polycarbonate resin as a main component, and the polycarbonate resin accounts for, for example, 50% by mass or more, preferably 70% by mass or more, more preferably 90% by mass or more, and most preferably 100% by mass of the total amount of resin constituting the present film.

[Film layer structure]
The present film may have a single layer structure or a multilayer structure. In the following description, a film with a multilayer structure may be referred to as a laminate film. In the case of a multilayer structure, each layer constituting the laminate film contains a resin, and the details of the resin constituting each layer are as described above.
Therefore, the resins constituting each layer are preferably thermoplastic resins, and it is preferable to use either a polycarbonate resin or a polyester resin, and it is more preferable to use a polycarbonate resin. The resins constituting each layer may be used alone or as a mixture of two or more types.

When a polycarbonate resin is used in each layer, the polycarbonate resin may be used alone or may be mixed with a resin other than the polycarbonate resin. The resin other than the polycarbonate resin may be a known resin that is commonly used, but it is also preferable to use a resin that is easily compatible with the polycarbonate resin, such as a polyester resin. Details of the polyester resin used in combination with the polycarbonate resin are as described above.
The resin constituting each layer of the present film preferably contains polycarbonate resin as a main component, and the polycarbonate resin accounts for, for example, 50% by mass or more, preferably 70% by mass or more, more preferably 90% by mass or more, and most preferably 100% by mass of the total amount of resin constituting each layer.

The layer structure of the laminated film is not particularly limited and may include two or more layers, but it is preferable for the film to have a surface layer/middle layer/surface layer structure, with surface layers provided on both sides of the middle layer. If the film has a surface layer/middle layer/surface layer structure, it may consist of three layers, but an adhesive layer or the like may be provided between the surface layer and middle layer, or two or more middle layers may be provided, resulting in a structure of three or more layers.

[Filling material]
As described above, the present film contains a filler. By containing the filler, the present film has low light transmittance and can exhibit hiding properties.
The filler content in the entire film is set to be more than 25.5% by mass based on the total amount of the film. If the filler content is less than 25.5% by mass, the hiding power cannot be sufficiently improved. Therefore, for example, when the film is used as an inlet sheet for an IC sheet or the like, an inlet such as an IC chip cannot be sufficiently hidden by an inlet sheet of an appropriate thickness.

By incorporating a large amount of filler as described above, this film can improve the laser markability of a laser marking sheet when it is laminated onto the film. The principle behind improving the laser marking ability of a laser marking sheet is unclear, but it is thought that this film, which contains a large amount of filler, reflects a lot of laser light, and this reflected light can improve the laser marking ability of a laser marking sheet laminated onto the film. Furthermore, when a laser marking sheet is laminated directly onto this film, carbonization by the laser light and color development by the laser color developer are more likely to occur at the interface, which is thought to further improve laser marking ability.

From the viewpoint of laser marking ability and hiding power, particularly from the viewpoint of laser marking ability, the content of the filler in the entire film is preferably 27% by mass or more, more preferably 29% by mass or more, even more preferably 30% by mass or more, still more preferably 31% by mass or more, even more preferably 33% by mass or more, still more preferably more than 35% by mass, even more preferably 36% by mass or more, still more preferably 37% by mass or more, still more preferably 39% by mass or more, and particularly preferably 40% by mass or more.
From the viewpoint of maintaining good mechanical properties such as bending resistance, the content of the filler in the entire film is preferably 60% by mass or less, more preferably 50% by mass or less, even more preferably 48% by mass or less, even more preferably 46% by mass or less, even more preferably 44% by mass or less, and particularly preferably 42% by mass or less.

The filler may be either inorganic or organic, but examples include inorganic fillers such as titanium oxide, talc, mica, calcium carbonate, barium oxide, zinc oxide, carbon black, silica, lead titanate, potassium titanate, zirconium oxide, zinc sulfide, antimony oxide, and zinc oxide. Among these, at least one filler selected from fillers with a refractive index of 2 or higher is preferred, with a refractive index of 2.2 or higher being more preferred, and a refractive index of 2.4 or higher being even more preferred. Examples of fillers with a refractive index of 2 or higher 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. Using a filler with a refractive index of 2 or higher further improves hiding power and laser marking properties. Furthermore, the film can be colored white. From these perspectives, titanium oxide is more preferred as a filler. The titanium oxide is not particularly limited, but examples include 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.

In the case of a laminate film, the present film may contain a filler in at least one layer, but it is preferable that all layers contain a filler. By containing a filler in all layers, the present film can be easily incorporated with a large amount of filler, which facilitates improving both laser coloring and hiding power. For example, in a laminate film having a surface layer/middle layer/surface layer structure, it is preferable that both surface layers and the middle layer contain a filler.
In the laminate film, the types of fillers contained in each layer may be different from each other, but are preferably the same. Therefore, it is preferable that all layers of the laminate film (for example, both surface layers and the middle layer) contain at least one filler selected from fillers having a refractive index of 2 or more, and more preferably titanium oxide.
The filler content in each layer may be adjusted so that the filler content in the entire film is within the above range, but it is preferable to incorporate the filler evenly in each layer. By incorporating the filler evenly in each layer, it is possible to prevent localized decreases in mechanical strength, such as bendability, and to improve the mechanical strength, such as bending resistance, of the entire film.
Therefore, the filler content in each layer (e.g., both surface layers and the middle layer) may be greater than 25.5% by mass based on the mass of each layer, and the preferred upper and lower limits of the filler content in each layer are the same as the preferred values for the filler content in the entire film described above.

[Impact modifier]
As described above, the present film contains an impact modifier. Even if the present film contains a large amount of filler such as titanium oxide, the addition of an impact modifier mitigates the effects of external impacts, such as bending and impacts, during actual use, making it easier to maintain good bending resistance. Furthermore, the film is more likely to maintain good processability by preventing the softening and fluidity reduction that occurs when heated due to the use of a specific resin, such as polycarbonate resin, or the inclusion of a large amount of filler such as titanium oxide. This reduces the likelihood of problems such as difficulty embedding IC chips.

Examples of the impact resistance improver include soft styrene resins and elastomers. The elastomer may be a core-shell type elastomer. The impact resistance improver may be used alone or in combination of two or more.
Among the above, the core-shell type elastomer is preferred as the impact resistance improver, as the use of the core-shell type elastomer further improves the impact resistance and the bending resistance.

Examples of the flexible styrene resin include a block copolymer containing a styrene polymer block and a conjugated diene polymer block, and a block copolymer containing a styrene polymer block and an acrylonitrile block.
The styrene content in the flexible styrene-based resin is, for example, 5% by mass or more and 80% by mass or less, preferably 10% by mass or more and 50% by mass or less, and more preferably 15% by mass or more and 30% by mass or less. When the styrene content is in the above range, the effect of imparting impact resistance is further improved.

As the conjugated diene polymer block used in the flexible styrene resin, a homopolymer of butadiene, isoprene, 1,3-pentadiene, or the like, a copolymer thereof, or a copolymer containing a monomer copolymerizable with the conjugated diene monomer in the block can be used.
Specific examples of soft styrene resins include styrene-butadiene-styrene block copolymers (SBS), styrene-isoprene-styrene block copolymers (SIS), silicone-acrylic composite rubber-acrylonitrile-styrene copolymers (SAS), methyl methacrylate-maleic anhydride-styrene copolymers (SMM), acrylonitrile-styrene copolymers (AS), acrylonitrile-butadiene-styrene copolymers (ABS), acrylonitrile-styrene-acrylic rubber copolymers (ASA), acrylonitrile-ethylene propylene rubber-styrene copolymers (AES), etc. Specific commercial products include the "Kraton D" series manufactured by Kraton Polymers, the "AR-100" series manufactured by Aron Kasei Corporation, the "Dialac" series manufactured by UMG ABS, and the "Delpet" series manufactured by Asahi Kasei Chemicals Corporation. As the soft styrene-based resin, the "Dynaron" series manufactured by JSR Corporation, the "Tuftec" series manufactured by Asahi Kasei Chemicals Corporation, the "Hybler" series manufactured by Kuraray Co., Ltd., and the like can be used as the styrene-based elastomer described below.

Block copolymers include pure blocks, random blocks, tapered blocks, etc., and there are no particular restrictions on the form of copolymerization. Furthermore, the block units may also be composed of multiple repeating units. Specifically, in the case of styrene-butadiene block copolymers, multiple block units may be repeated, such as in styrene-butadiene copolymers, styrene-butadiene-styrene block copolymers, and styrene-butadiene-styrene-butadiene block copolymers.

Hydrogenated styrene-butadiene-styrene block copolymers (SEBS) and hydrogenated styrene-isoprene-styrene block copolymers (SEPS), in which some or all of the double bonds in the conjugated diene polymer blocks of SBS and SIS have been hydrogenated, can also be used. Specific examples of such products include the "Tuftec H" series manufactured by Asahi Kasei Chemicals Corporation and the "Kraton G" series manufactured by Kraton Polymers.

A polar functional group can also be added to the flexible styrene-based resin. Specific examples of the polar functional group include an acid anhydride group, a carboxylic acid group, a carboxylic acid ester group, a carboxylic acid chloride group, a carboxylic acid amide group, a carboxylic acid salt group, a sulfonic acid group, a sulfonic acid ester group, a sulfonic acid chloride group, a sulfonic acid amide group, a sulfonic acid salt group, an epoxy group, an amino group, an imide group, and an oxazoline group. Among these, it is preferable to add an acid anhydride group or an epoxy group.
As the flexible styrene-based resin to which a polar functional group is imparted, modified SEBS and SEPS are preferably used. Specific examples include maleic anhydride-modified SEBS, maleic anhydride-modified SEPS, epoxy-modified SEBS, and epoxy-modified SEPS. Specific commercial products include the "Tuftec M" series manufactured by Asahi Kasei Chemicals Corporation, the "Dynaron" series manufactured by JSR Corporation, and the "Epofriend" series manufactured by Daicel Chemical Industries, Ltd.

The soft styrene-based resin may also be a styrene-based elastomer containing an elastomer component. Specific examples of the above include block copolymers of a styrene component with butadiene, isoprene, 1,3-pentadiene, etc., and modified or hydrogenated versions of these may also be used. More specific examples include SBS, SIS, SEBS, and SEPS.

The elastomer may be other than a styrene-based elastomer, and examples include known elastomers such as polyester-based elastomers, polyolefin-based elastomers, diene-based elastomers, acrylic-based elastomers, polyamide-based elastomers, polyurethane-based elastomers, fluorine-based elastomers, and silicone-based elastomers. Elastomers are generally thermoplastic elastomers. The elastomer is preferably a polyester-based elastomer or the above-mentioned styrene-based elastomer.

The polyester-based elastomer is a thermoplastic polyester that has rubber properties at room temperature, preferably a thermoplastic elastomer primarily composed of a polyester-based block copolymer, and is preferably a block copolymer having a high-melting-point, highly crystalline aromatic polyester as the hard segment and an amorphous polyester or amorphous polyether as the soft segment. The soft segment content of the polyester-based elastomer is at least 20 to 95 mol% of the total segments, and in the case of a block copolymer of polybutylene terephthalate and polytetramethylene glycol (PTMG-PBT copolymer), it is 50 to 95 mol%. The preferred soft segment content is 50 to 90 mol%, particularly 60 to 85 mol%. Of these, polyester ether block copolymers, especially PTMG-PBT copolymers, are preferred.

A core-shell elastomer is composed of an innermost layer (i.e., a core) and one or more outer layers (i.e., shells) covering it. The core-shell elastomer is preferably a core-shell graft copolymer in which a graft-copolymerizable monomer component is graft-copolymerized onto the core to form the shell.

The core-shell graft copolymer has a polymer component, usually called a rubber component, as the core. In the core-shell graft copolymer, the polymer component constituting the core is preferably graft-copolymerized with a monomer component copolymerizable with this polymer component as the shell.
The core-shell graft copolymer may be produced by any of bulk polymerization, solution polymerization, suspension polymerization, emulsion polymerization, etc., and the copolymerization method may be single-stage grafting or multi-stage grafting. However, commercially available core-shell elastomers can usually be used as they are. Examples of commercially available core-shell elastomers will be given later.

Specific examples of polymer components that form the core include butadiene-based rubbers such as polybutadiene and styrene-butadiene copolymers, isoprene-based rubbers, acrylic rubbers such as polybutyl acrylate, poly(2-ethylhexyl acrylate), and butyl acrylate-2-ethylhexyl acrylate copolymers, silicone-based rubbers such as polyorganosiloxane rubber, butadiene-acrylic composite rubbers, and silicone-acrylic composite rubbers such as IPN (Interpenetrating Polymer Network) composite rubbers made of polyorganosiloxane rubber and polyalkyl acrylate rubber, ethylene-α-olefin-based rubbers such as ethylene-propylene copolymers, ethylene-butene copolymers, and ethylene-octene copolymers, ethylene-acrylic rubbers, and fluororubbers. These may be used alone or in combination. Among these, from the standpoint of mechanical properties and surface appearance, at least one selected from butadiene rubber, acrylic rubber, silicone rubber, and silicone-acrylic composite rubber is preferred, with at least one selected from butadiene rubber and silicone-acrylic composite rubber being more preferred.

Specific examples of the monomer component constituting the shell and capable of graft copolymerization with the core polymer component include aromatic vinyl compounds; vinyl cyanide compounds; (meth)acrylic compounds such as (meth)acrylic acid ester compounds, (meth)acrylic acid compounds, and epoxy group-containing (meth)acrylic acid ester compounds such as glycidyl (meth)acrylate; maleimide compounds such as maleimide, N-methylmaleimide, and N-phenylmaleimide; α,β-unsaturated carboxylic acid compounds such as maleic acid, phthalic acid, and itaconic acid, and anhydrides thereof (e.g., maleic anhydride). These monomer components may be used alone or in combination of two or more. Among these, aromatic vinyl compounds, vinyl cyanide compounds, and (meth)acrylic compounds are preferred from the viewpoints of mechanical properties and surface appearance, and aromatic vinyl compounds and (meth)acrylic compounds, especially (meth)acrylic acid ester compounds, are more preferred.
Specific examples of the aromatic vinyl compound include styrene, α-methylstyrene, 1-vinylnaphthalene, 4-methylstyrene, 4-propylstyrene, 4-cyclohexylstyrene, 4-dodecylstyrene, 2-ethyl-4-benzylstyrene, 4-(phenylbutyl)styrene, and halogenated styrenes, and among these, styrene and α-methylstyrene are more preferred.
Specific examples of the (meth)acrylic acid ester compound include methyl (meth)acrylate, ethyl (meth)acrylate, butyl (meth)acrylate, cyclohexyl (meth)acrylate, and octyl (meth)acrylate. Among these, methyl (meth)acrylate and ethyl (meth)acrylate, which are relatively easily available, are preferred, and methyl (meth)acrylate is more preferred. Note that "(meth)acrylic" collectively refers to "acrylic" and "methacrylic."

As the core-shell elastomer, a core-shell graft copolymer is particularly preferred, which comprises a core made of at least one polymer component selected from butadiene rubber, acrylic rubber, silicone rubber, and silicone-acrylic composite rubber, and a shell formed by graft copolymerizing a (meth)acrylic compound such as a (meth)acrylic acid ester or an aromatic vinyl compound around the core. The content of the polymer component in the core of the core-shell graft copolymer is preferably 40% by mass or more, more preferably 60% by mass or more, more preferably 70% by mass or more, and even more preferably 80% by mass or more.
Furthermore, the total content of the (meth)acrylic compound (especially, the (meth)acrylic acid ester) component and the aromatic vinyl compound component in the shell of the core-shell graft copolymer is preferably 30% by mass or more, more preferably 50% by mass or more, even more preferably 60% by mass or more, and even more preferably 70% by mass or more. In the shell, either the (meth)acrylic compound or the aromatic vinyl compound may be used alone, or these may be used in combination.

Specific preferred examples of core-shell elastomers include methyl methacrylate-butadiene-styrene copolymer (MBS), methyl methacrylate-acrylonitrile-butadiene-styrene copolymer (MABS), methyl methacrylate-butadiene copolymer (MB), methyl methacrylate-acrylic rubber copolymer (MA), methyl methacrylate-acrylic rubber-styrene copolymer (MAS), methyl methacrylate-acrylic-butadiene rubber copolymer, methyl methacrylate-acrylic-butadiene rubber-styrene copolymer, and methyl methacrylate-(acrylic-silicone composite rubber) copolymer.

Commercially available core-shell type graft copolymers include, for example, "Paraloid EXL2602", "Paraloid EXL2603", "Paraloid EXL2690", "Paraloid EXL2691J", "Paraloid EXL2650J", "Paraloid EXL2655", "Paraloid EXL2311", "Paraloid EXL2313", "Paraloid EXL2315", "Paraloid KM330", "Paraloid KM336P", and "Paraloid KCZ201", all manufactured by Dow Chemical Japan. Examples of such polymers include "Metablen C-223A,""MetablenE-901,""MetablenS-2001,""MetablenW-450A,""MetablenSRK-200," and "Metablen E-870A" manufactured by Mitsubishi Chemical Corporation, and "Kane Ace M-210,""Kane Ace M-511,""Kane Ace M-600,""Kane Ace M-400,""Kane Ace M-580,""Kane Ace M-590,""Kane Ace M-711,""Kane Ace MR-01," and "Kane Ace M-300" manufactured by Kaneka Corporation.
These impact resistance improvers such as core-shell type graft copolymers may be used alone or in combination of two or more.

The content of the impact modifier in the entire film is preferably 1% by mass or more and 30% by mass or less, based on the total amount of the film. When the content of the impact modifier is 1% by mass or more, the effects of external impact are moderately mitigated, and bending resistance and other properties tend to be improved. In addition, softening and a decrease in fluidity when the film is heated, which are caused by the type of resin used or the incorporation of a large amount of filler, are prevented, and good processability tends to be maintained.
On the other hand, by setting the content to 30% by mass or less, effects commensurate with the content can be exhibited, and the film can be prevented from deteriorating in various physical properties such as heat resistance, or from becoming too fluid during processing.
From these viewpoints, the content of the impact modifier in the entire film is more preferably 1.5% by mass or more, even more preferably 2% by mass or more, even more preferably 2.5% by mass or more, and particularly preferably 3% by mass or more, and is more preferably 20% by mass or less, even more preferably 15% by mass or less, even more preferably 10% by mass or less, particularly preferably 8% by mass or less, and most preferably 6% by mass or less.

In the case of a laminate film, at least one layer of the present film may contain an impact modifier. Although all layers of the laminate film may contain an impact modifier, it is preferred that at least the surface layer constituting the outermost layer of the film contains an impact modifier.
Therefore, in a laminate film having a surface layer/middle layer/surface layer structure, it is preferable that both surface layers contain an impact modifier, and therefore both surface layers preferably contain an impact modifier in addition to a resin and a filler. On the other hand, it is preferable that the middle layer contains a resin and a filler, but does not contain an impact modifier, or if it does contain an impact modifier, it contains a lower amount of impact modifier than both surface layers.
In this way, by containing a relatively large amount of filler in both surface layers, the bending resistance and impact resistance can be improved, and processability can be improved, making it easier to embed IC chips and the like, without having to increase the content of impact resistance improver in the entire film.

The content of the impact resistance improver in each of the two surface layers is preferably 2% by mass or more, more preferably 4% by mass or more, even more preferably 6% by mass or more, even more preferably 8% by mass or more, based on the mass of each layer, and is preferably 40% by mass or less, more preferably 30% by mass or less, even more preferably 25% by mass or less, even more preferably 20% by mass or less, and particularly preferably 15% by mass or less.
On the other hand, as described above, the content of impact modifier in the middle layer should be less than the content of impact modifier in each of the surface layers, based on the mass of each layer, and is preferably less than 4 mass%, more preferably less than 2 mass%, even more preferably 1 mass% or less, even more preferably 0.5 mass% or less, and most preferably 0 mass%.

[Heat stabilizer/antioxidant (additive (X))]
The present film preferably contains at least one additive (X) selected from a heat stabilizer and an antioxidant. As described above, the present film contains a large amount of filler, which may cause foaming and lead to poor appearance. However, by containing the additive (X), foaming can be suppressed, thereby improving the appearance of the film.
The present film may contain, as the additive (X), either a heat stabilizer or an antioxidant, or both of them, but it is preferable to contain at least a heat stabilizer, and it is more preferable to use a heat stabilizer and an antioxidant in combination.

(Heat stabilizer)
Examples of heat stabilizers include phosphorus-based compounds. Known phosphorus-based compounds can be used. Specific examples include phosphorus oxoacids such as phosphoric acid, phosphonic acid, phosphorous acid, phosphinic acid, and polyphosphoric acid; metal acid pyrophosphates such as sodium acid pyrophosphate, potassium acid pyrophosphate, and calcium acid pyrophosphate; phosphates of Group 1 or Group 2B metals such as potassium phosphate, sodium phosphate, cesium phosphate, and zinc phosphate; organic phosphite compounds, organic phosphate compounds, and organic phosphonite compounds. Metal salts of the organic phosphate compounds, organic phosphite compounds, and organic phosphonite compounds may also be used.

Organophosphite compounds include triphenyl phosphite, tris(mononylphenyl)phosphite, tris(mononyl/dinonyl phenyl)phosphite, tris(2,5-di-tert-butylphenyl)phosphite, tris(2,4-di-tert-butylphenyl)phosphite, tris[2,4-bis(1,1-dimethylpropyl)phenyl]phosphite, tris(mono-/di-tert-butylphenyl)phosphite, monooctyldiphenylphosphite, dioctylmonophenylphosphite, monodecyldiphenylphosphite, and didecylmonophenylphosphite. Examples of phosphite include various phosphite esters such as bis(2,6-di-tert-butylphenyl)octyl phosphite, tridecyl phosphite, trilauryl phosphite, tristearyl phosphite, 2,2-methylenebis(4,6-di-tert-butylphenyl)octyl phosphite, 4,4'-butylidene-bis(3-methyl-6-t-butylphenyl-di-tridecyl phosphite), cyclic neopentanetetraylbis(2,6-di-t-butyl-4-methylphenyl phosphite), and 3,9-bis(2,6-di-tert-butyl-4-methylphenoxy)-2,4,8,10-tetraoxa-3,9-diphosphaspiro[5,5]undecane. Among these, trialkyl phosphites such as tristearyl phosphite are preferred.

The organic phosphite compound may also be a phosphite ester having at least one oxetane group. Such an oxetane group-containing phosphite ester may have one, two, or three oxetane groups.
Examples of oxetane group-containing phosphites include tris[(3-ethyloxetan-3-yl)methyl]phosphite, bis[(3-ethyloxetan-3-yl)methyl]phosphite, mono[(3-ethyloxetan-3-yl)methyl]phosphite, tris[(3-pentyloxetan-3-yl)methyl]phosphite, bis[(3-pentyloxetan-3-yl)methyl]phosphite, tris[(3-hexa decyloxetan-3-yl)methyl]phosphite, bis[(3-hexadecyloxetan-3-yl)methyl]phosphite, tris[(3-phenyloxetan-3-yl)methyl]phosphite, bis[(3-phenyloxetan-3-yl)methyl]phosphite, tris[(3-p-tolyloxetan-3-yl)methyl]phosphite, bis[(3-p-tolyloxetan-3-yl)methyl]phosphite , tris[(3-benzyloxetan-3-yl)methyl]phosphite, bis[(3-benzyloxetan-3-yl)methyl]phosphite, phenylbis[(3-ethyloxetan-3-yl)methyl]phosphite, 2-phenoxyspiro(1,3,2-dioxaphosphorinane-5,3'-oxetane), 3,3-bis[spiro(oxetane-3',5"-(1",3",2"-dioxa-2"-phosphorinane)) -oxymethyl]oxetane and P,P'-[(1-methylethylidene)-di-4,1-phenylene]-P,P,P',P'-tetrakis[(3-ethyl-3-oxetanyl)methyl]phosphite. Furthermore, the oxetane group-containing phosphites described in U.S. Patent No. 3,209,013 can also be used as appropriate. Use of the oxetane group-containing phosphites makes it easier to increase the color intensity after the dye has developed a color.

The organic phosphate compound is preferably an organic phosphate ester compound or a metal salt of an organic phosphate ester compound, and the metal is more preferably at least one metal selected from groups Ia, IIa, IIb, IIIa, and IIIb of the periodic table, and among these, magnesium, barium, calcium, zinc, and aluminum are even more preferred, with magnesium, calcium, or zinc being particularly preferred.
Furthermore, the organic phosphate compound is preferably an acidic organic phosphate ester or a metal salt thereof. Examples of the acidic organic phosphate ester include dialkyl acid phosphate, monoalkyl acid phosphate, diaryl acid phosphate, and monoalkyl monoaryl acid phosphate. The alkyl group in the acidic organic phosphate ester is, for example, an alkyl group having 1 to 30 carbon atoms, preferably 2 to 25 carbon atoms, and more preferably 6 to 23 carbon atoms. The aryl group may have about 6 to 30 carbon atoms.

Preferred specific examples of organic phosphate ester compounds include acidic organic phosphate esters such as distearyl acid phosphate and monostearyl acid phosphate. Metal salts of acidic organic phosphate esters include bis(distearyl acid phosphate) zinc salt, monostearyl acid phosphate zinc salt, tris(distearyl acid phosphate) aluminum salt, a salt of monostearyl acid phosphate and two monostearyl acid phosphate aluminum salts, monostearyl acid phosphate, and distearyl acid phosphate. Among these, distearyl acid phosphate and monostearyl acid phosphate are more preferred.

Organophosphonite compounds include tetrakis(2,4-di-iso-propylphenyl)-4,4'-biphenylene diphosphonite, tetrakis(2,4-di-n-butylphenyl)-4,4'-biphenylene diphosphonite, tetrakis(2,4-di-tert-butylphenyl)-4,4'-biphenylene diphosphonite, tetrakis(2,4-di-tert-butylphenyl)-4,3'-biphenylene diphosphonite, and tetrakis(2,4-di-tert-butylphenyl)-3,3'-biphenylene diphosphonite. Examples include tetrakis(2,6-di-iso-propylphenyl)-4,4'-biphenylene diphosphonite, tetrakis(2,6-di-n-butylphenyl)-4,4'-biphenylene diphosphonite, tetrakis(2,6-di-tert-butylphenyl)-4,4'-biphenylene diphosphonite, tetrakis(2,6-di-tert-butylphenyl)-4,3'-biphenylene diphosphonite, and tetrakis(2,6-di-tert-butylphenyl)-3,3'-biphenylene diphosphonite.

Among the above phosphorus-based compounds, at least one selected from organic phosphite compounds and organic phosphate ester compounds is preferred from the viewpoints of improving thermal stability, inhibiting oxidation, and inhibiting foaming. It is also preferable to use organic phosphite compounds in combination with the antioxidants described below, and more specifically, it is more preferable to use them in combination with phenolic antioxidants. Use in combination with a phenolic antioxidant can effectively inhibit foaming in the film. It also effectively prevents molecular weight reduction and yellowing of the resin during extrusion film formation, and can achieve both stability during extrusion film formation and long-term stability as a molded product.

The phosphorus-based compound can also be used as an ester exchange inhibitor that can inhibit the ester exchange reaction between a polyester resin and a polycarbonate resin. Therefore, when the present film contains both a polyester resin and a polycarbonate resin as resins, ester exchange in the present film can also be prevented. Furthermore, when the present film contains a polyester resin or a polycarbonate resin, ester exchange with the polycarbonate resin or polyester resin contained in a layer adjacent to the present film in a laminate including the present film can also be prevented.
In the present film, the above-mentioned heat stabilizers may be used alone or in combination of two or more.

(antioxidant)
As the antioxidant, for example, a phenol-based antioxidant, a sulfur-based antioxidant, etc. can be used, and among these, a phenol-based antioxidant is preferred.

Phenol-based antioxidants include α-tocopherol, 4-methoxyphenol, 4-hydroxyphenyl (meth)acrylate, β-tocopherol, 2,6-di-tert-butylphenol, 2,6-di-tert-4-methoxyphenol, 2-tert-butyl-4-methoxyphenol, 2,4-dimethyl-6-tert-butylphenol, 2,6-di-tert-butyl-4-methylphenol (dibutylhydroxytoluene, BHT), and stearyl-β-(3,5-di-tert-butyl-4-hydroxyphenyl) propionate. Of these, 2,6-di-tert-butyl-4-methylphenol (dibutylhydroxytoluene, BHT) is preferred.

Sulfur-based antioxidants include thiodipropionic acid, dilauryl thiodipropionate, distearyl thiodipropionate, laurylstearyl thiodipropionate, dimyristyl thiodipropionate, distearyl-β,β'-thiodibutyrate, thiobis(β-naphthol), thiobis(N-phenyl-β-naphthylamine), 2-mercaptobenzothiazole, 2-mercaptobenzimidazole, tetramethylthiuram monosulfide, tetramethylthiuram disulfide, and nickel dibutyldithiocarbamate.

In the case of a laminate film, the additive (X) may be contained in at least one layer of the laminate film, but from the viewpoint of foaming suppression, it is preferable to contain it in the layer containing the filler. In the case of the present film, it is preferable to contain the filler in all layers, and it is also preferable to contain the additive (X) in all layers.
For example, when the present film has a laminated structure of surface layer/middle layer/surface layer, it is preferable that the additive (X) is contained in both the middle layer and both surface layers.

In the present film, foaming is likely to occur when a polycarbonate resin with a high molecular weight is used as the resin. Therefore, when a high-molecular-weight polycarbonate resin with a high molecular weight is used as the resin in the present film, it is preferable to contain additive (X). Specifically, the high-molecular-weight polycarbonate resin is a polycarbonate resin with a mass-average molecular weight of 58,000 or more, preferably a polycarbonate resin with a mass-average molecular weight of 60,000 or more, and more preferably a polycarbonate resin with a mass-average molecular weight of 63,000 or more and 120,000 or less. Therefore, in the case of a laminate film, it is preferable to contain additive (X) in the layer in which the high-molecular-weight polycarbonate resin is used as the resin.
Furthermore, when the filler is contained in a large amount, specifically when the filler is contained in an amount greater than 30% by mass, further 31% by mass or more, further 33% by mass or more, further 35% by mass or more, further 36% by mass or more, further 37% by mass or more, further 39% by mass or more, and particularly 40% by mass or more, mechanical properties such as impact resistance, dynamic bending durability, and toughness tend to be easily reduced, and therefore it is preferable to use a high molecular weight polycarbonate resin as described above.

On the other hand, when a low-molecular-weight polycarbonate resin having a low molecular weight is used as the polycarbonate resin in the present film, foaming is unlikely to occur, so additive (X) does not need to be contained. Similarly, in the case of a laminate film, additive (X) does not need to be contained in the layer in which a low-molecular-weight polycarbonate resin is used as the polycarbonate resin.
Specifically, the low molecular weight polycarbonate resin is a polycarbonate resin having a mass average molecular weight of less than 58,000, preferably a polycarbonate resin having a mass average molecular weight of 56,000 or less, and more preferably a polycarbonate resin having a mass average molecular weight of 20,000 or more and 54,000 or less.

The content of additive (X) in the entire film is preferably 0.01% by mass or more and 3% by mass or less, based on the total amount of the film. By setting the content of additive (X) to 0.01% by mass or more, the effect of adding additive (X) can be appropriately exhibited, for example, foaming can be effectively suppressed. Furthermore, by setting the content to 3% by mass or less, an effect commensurate with the content can be exhibited.
From these viewpoints, the content of the additive (X) is more preferably 0.05% by mass or more, even more preferably 0.1% by mass or more, and more preferably 2% by mass or less, even more preferably 1% by mass or less, and even more preferably 0.6% by mass or less.

As described above, the present film may contain a combination of a heat stabilizer and an antioxidant as additive (X). In this case, the mass ratio of the antioxidant to the heat stabilizer (antioxidant/heat stabilizer) is preferably 1/9 or more and 9/1 or less, more preferably 2/8 or more and 8/2 or less, and even more preferably 3/7 or more and 7/3 or less.

When the film is a laminate film, the types of additive (X) contained in each layer of the laminate film may be different or the same. Furthermore, in the case of a laminate film, the content of filler in each layer may be adjusted so that the content of filler in the entire film is within the above-mentioned range. However, the preferred upper and lower limits of the content of additive (X) in each layer containing additive (X) and the preferred range of the mass ratio (antioxidant/thermal stabilizer) are the same as the preferred upper and lower limits of the content of additive (X) in the entire film, as well as the preferred range of the mass ratio (antioxidant/thermal stabilizer) described above.

[Antistatic agent]
The present film may contain an antistatic agent. The inclusion of an antistatic agent in the present film tends to improve handleability, such as by suppressing static buildup during transport or when stacked on other films, and by reducing adhesion to press plates during heat pressing and other processes. Furthermore, the film's low surface resistivity reduces static electricity generation when unwinding the film from a film roll, effectively preventing sparks from being generated during unwinding, which could scratch the surface of the film, and effectively preventing the film from meandering or skewing during unwinding, resulting in misalignment, twisting, wrinkles, and other problems. This improves handleability and processability. Additionally, the low surface resistivity reduces the likelihood of floating dust particles being attracted by static electricity and adhering to the surface of the film, which could lead to the inclusion of foreign matter in the resulting laminate film, card, passport, or other products, thereby improving dust resistance.
Examples of the antistatic agent include low molecular weight antistatic agents, polymeric antistatic agents, etc. These may be either ion-conductive or electron-conductive.

Examples of low molecular weight antistatic agents include anionic antistatic agents, cationic antistatic agents, nonionic antistatic agents, amphoteric antistatic agents, complex compounds, metal alkoxides such as alkoxysilane, alkoxytitanium, and alkoxyzirconium, and derivatives thereof; and coated silica.
The amphoteric antistatic agent may be a betaine type, but may also be a type other than a betaine type, and may be any antistatic agent composed of a cation and an anion, or may be an ionic liquid.
The polymeric antistatic agent may be, for example, a polymer such as a vinyl copolymer having a metal sulfonate, such as a metal alkylsulfonate or a metal alkylbenzenesulfonate, in the molecule, or may be a betaine type. Furthermore, polyamide elastomers, polyester elastomers, etc. may also be used.
The antistatic agents may be used alone or in combination of two or more.

Of the above antistatic agents, those composed of a cation and an anion are preferred, and specific examples include antistatic agents composed of an anion selected from a sulfonimide anion containing a fluorine atom and a sulfonate anion containing a fluorine atom, and a cation selected from a phosphonium cation, an ammonium cation, an imidazolium cation, and a pyridinium cation.
The antistatic agent composed of cations and anions is preferably an ionic liquid. Ionic liquids have high electrical conductivity and are liquid at around room temperature, so they have excellent dispersibility and exhibit higher antistatic performance. They also have excellent heat resistance, making it possible to impart excellent antistatic performance while suppressing deterioration of physical properties due to thermal decomposition of the antistatic agent. Note that an ionic liquid refers to a compound composed only of ions and having a melting point of 100°C or less.

The anion selected from the above-mentioned sulfonimide anions containing fluorine atoms and sulfonate anions containing fluorine atoms preferably includes an anion selected from perfluoroalkylsulfonimide anions and perfluoroalkylsulfonate anions. By including a fluorine atom, particularly a perfluoroalkyl group, the anion tends to improve the migration of the ionic liquid to the surface of the film. Therefore, it is possible to impart high antistatic performance with a lower addition amount.

As the antistatic agent composed of the above-mentioned anion and cation, an antistatic agent represented by the following formula (4) is preferred.
[(R ₁₁ ) ₄ P ⁺ ]・(R ₁₂ SO ₂ )(R ₁₂ SO ₂ )N ⁻ (4)
(In the above formula (4), each R ₁₁ independently represents a hydrocarbon group, and each R ₁₂ independently represents a hydrocarbon group containing a fluorine atom.)

In formula (4), R ₁₁ is preferably independently selected from a linear, branched, or cyclic alkyl group, a linear, branched, or cyclic alkenyl group, and an aryl group, more preferably a linear or branched alkyl group, and even more preferably a linear alkyl group. Each R ₁₁ may have a substituent, but preferably does not have a substituent.
The number of carbon atoms constituting the hydrocarbon group of R ₁₁ is, for example, 1 to 20, preferably 1 to 12, more preferably 1 to 8, even more preferably 1 to 6, and even more preferably 1 to 4. As described above, the hydrocarbon group is preferably an alkyl group, and therefore, R ₁₁ is most preferably an alkyl group having 1 to 4 carbon atoms. Multiple R ₁₁ in one molecule may be the same or different.
When multiple R ₁₁ are different in one molecule, it is preferable that the number of carbon atoms constituting the hydrocarbon group of three R ₁₁ is the same, and the number of carbon atoms constituting the hydrocarbon group of another R ₁₁ is different. The number of carbon atoms constituting the hydrocarbon group of three R ₁₁ is, for example, 9 or less, preferably 4 to 9, more preferably 5 to 8, and even more preferably 6 to 7. The number of carbon atoms constituting the hydrocarbon group of another R ₁₁ is, for example, 10 or more, preferably 10 to 18, more preferably 11 to 16, and even more preferably 12 to 14. As described above, the hydrocarbon group is preferably an alkyl group.

R ₁₂ is preferably each independently selected from a linear, branched or cyclic alkyl group containing a fluorine atom, a linear, branched or cyclic alkenyl group containing a fluorine atom, and an aryl group containing a fluorine atom, more preferably a linear or branched alkyl group containing a fluorine atom, and still more preferably a linear alkyl group containing a fluorine atom.
In each R ₁₂ , the hydrocarbon group preferably has 1 to 10 carbon atoms, more preferably 1 to 6 carbon atoms, even more preferably 1 to 4 carbon atoms, and even more preferably 1 to 3 carbon atoms.
More specifically, each R ₁₂ is independently preferably a perfluorohydrocarbon group, more preferably a perfluoroalkyl group, further preferably a perfluoromethyl group or a perfluoroethyl group, and even more preferably a perfluoromethyl group.
Multiple R ₁₂ groups in one molecule may be the same or different.

The antistatic agent represented by formula (4) is preferably a compound represented by the following formula (5).

In films with a single-layer structure, it is preferable that the single layer contain an antistatic agent. In laminate films, the antistatic agent needs to be contained in at least one layer of the laminate film, and may be contained in all layers. However, the antistatic agent is preferably contained in the surface layer. Therefore, in laminate films with a surface layer/middle layer/surface layer structure, it is preferable that both surface layers contain an antistatic agent. By containing an antistatic agent in both surface layers, it is easier to achieve the above-mentioned effects, such as effectively suppressing static buildup in the film and improving handleability.

When the antistatic agent is composed of a cation and anion, the content of the antistatic agent in each layer is preferably 0.1% by mass to 3% by mass, more preferably 0.2% by mass to 2.5% by mass, even more preferably 0.3% by mass to 2% by mass, and even more preferably 0.4% by mass to 1.5% by mass. When other antistatic agents are used, the content of the antistatic agent in each layer is preferably 0.1% by mass to 5% by mass, more preferably 0.2% by mass to 4% by mass, even more preferably 0.4% by mass to 3% by mass, and even more preferably 0.5% by mass to 2% by mass.

(Other ingredients)
The present film may contain additives other than those mentioned above (other additives) that are commonly used in card or passport films. Examples of other additives include lubricants, process stabilizers, UV absorbers, light stabilizers, matting agents, processing aids, metal deactivators, residual polymerization catalyst deactivators, antibacterial and antifungal agents, antiviral agents, and flame retardants. When the present film is a laminate film, at least one of the multiple layers constituting the laminate film may contain at least one of the other additives mentioned above, or all of the layers may contain at least one of the other additives.

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, 300 μm or less, preferably 250 μm or less, more preferably 200 μm or less, and even more preferably 170 μm or less. By making the thickness of the present film a certain level or more, it becomes easier to ensure concealment properties. On the other hand, by making the thickness below a certain level, it becomes easier to make cards or passports thinner and to add layers such as security functions to the transparent layer.

Furthermore, when the present film has a surface layer/middle layer/surface layer structure, the thickness ratio of each surface layer to the middle layer (each surface layer/middle layer) is preferably 0.03 or more and 0.85 or less, more preferably 0.05 or more and 0.7 or less, even more preferably 0.1 or more and 0.5 or less, and even more preferably 0.15 or more and 0.35 or less. By keeping the thickness ratio within the above range, the surface layer and middle layer each tend to perform their appropriate functions. For example, as described above, by incorporating an impact modifier in the surface layer and increasing its content compared to the middle layer, the effect of using the impact modifier can be effectively exerted while suppressing the content of the impact modifier in the entire film.

(Light transmission density of this film)
The light transmission density of the present film is preferably 0.8 or more. By setting the light transmission density to 0.8 or more, the concealing properties of the present film are improved, and inlets such as IC chips can be appropriately concealed by the present film. From the viewpoint of improving the concealing properties of the present film, the light transmission density of the present film is more preferably 0.85 or more, even more preferably 0.9 or more, even more preferably 0.95 or more, even more preferably 0.97 or more, particularly preferably 1 or more, and most preferably 1.05 or more. The upper limit of the light transmission density is not particularly limited, but from the viewpoint of preventing the thickness of the present film from becoming unnecessarily thick, it may be, for example, 3 or less, or 2.5 or less. The light transmission density can be measured by the method described in the examples.

(Method for manufacturing card or passport film)
The card or passport film (the present film) can be produced by a known method, but it is preferable to obtain a resin composition for forming the present film and then form the resin composition into a film.
The resin composition may be obtained by mixing raw materials constituting the resin composition, such as a resin, a filler, an impact resistance improver, and optionally an additive (X), an antistatic agent, and other components.
The raw materials may be mixed by melt-kneading while heating in an extruder, plastomill, or the like, but the raw materials constituting the resin composition may also be dry-blended in a tumbler or the like and used as is.
The method for forming the resin composition into a film is not particularly limited, and may be press molding or extrusion molding, with extrusion molding being preferred from the standpoints of productivity and cost.

When the present film is a laminated film, a resin composition for forming each layer may be prepared, and multiple resin layers may be laminated by a known lamination method while forming each resin layer from each resin composition. Alternatively, a resin composition for forming another resin layer may be melt-extruded onto a resin film formed from one of the resin compositions. Alternatively, a multilayer structure may be formed by co-extrusion. From the viewpoints of productivity, cost, etc., it is preferable to adopt a co-extrusion method.
In the laminated film, the resin composition for forming each layer may be obtained by mixing components for forming each layer according to the composition of each layer.
For example, in the case of a laminated film having a surface layer/middle layer/surface layer structure, a surface layer resin composition containing at least a resin, a filler, and an impact resistance improver for forming the surface layer, and a middle layer resin composition containing at least a resin and a filler for forming the middle layer, can be prepared, and the laminated film can be molded using these resin compositions.

<Card or passport>
The film is used for cards or passports, including IC cards, magnetic cards, driver's licenses, residence cards, qualification certificates, employee ID cards, student ID cards, My Number cards, seal registration certificates, vehicle inspection certificates, tag cards, prepaid cards, cash cards, credit cards, ETC cards, SIM cards, and B-CAS cards.
The card or passport (more specifically, the data page of the passport) may include a core sheet. The data page of the card or passport may also include, in addition to the core sheet, at least one of a laser marking sheet, a printing sheet, and a protective sheet. The data page of the passport or card may be produced by stacking the core sheet and one or more sheets selected from the above-mentioned sheets other than the core sheet, pressing them together to heat-seal them, and then performing a punching process or the like. Instead of heat-sealing, the sheets may be bonded together using an appropriate adhesive or the like.

In the present invention, a card or passport comprises the above-described present film. A card or passport typically comprises multiple resin films, at least one of which is preferably composed of the present film, but the present film is preferably used as a core sheet in a card or passport. In particular, the present film preferably constitutes an inlet sheet that incorporates inlets such as IC chips and antennas, and more preferably constitutes an IC sheet that incorporates an IC chip.

The film has high concealing properties, so when used as a core sheet, particularly as an inlet sheet for an IC sheet, it can adequately conceal inlets such as IC chips and antennas even if the inlet sheet is thin.
Furthermore, the inclusion of the impact modifier in the present film as described above prevents the softening and fluidity reduction caused by the incorporation of a large amount of filler when heated, thereby maintaining good processability. Therefore, even when the present film is used as an inlet sheet, problems such as difficulty in embedding IC chips are less likely to occur.
When the present film is used for an inlet sheet such as an IC sheet, it is preferable to use two or more sheets laminated together, more preferably three or more sheets laminated together, and even more preferably four or more sheets laminated together. When laminating, the present sheet may be laminated directly to another present sheet, or other layers such as an adhesive layer may be present as needed. By laminating the present film to form an inlet sheet in this manner, it is possible to more easily embed inlets such as IC chips and antennas compared to an inlet sheet consisting of a single layer of the present film. Furthermore, since IC chips and the like are available in various thicknesses, the inlet sheet configuration shown in Figure 1 (described below) has the advantage of allowing the thickness of the present film on the inner side to be adjusted depending on the thickness of the IC chip. Additionally, the present film on both surfaces of the inlet sheet is positioned above and below the IC chip, thereby providing the advantage of adequately concealing the inlet of the IC chip.

Furthermore, when two or more sheets of this film are laminated in this way to form an inlet sheet, there is the advantage that it is easy to adjust the overall thickness of the product when it is laminated with other resin films, such as laser marking sheets or printing sheets, to form actual products such as cards or passports.

Fig. 1 shows an example of an IC sheet as an inlet sheet to which the present film is applied. As shown in Fig. 1, the IC sheet (inlet sheet) 11 is formed by laminating a plurality of resin films 10 so that an inlet such as an IC chip 12 is built in. For example, it is preferable to form the IC sheet by laminating two or more resin films 10 with the inlet sandwiched between them and integrating them by heat sealing or the like.
1, the IC sheet (inlet sheet) 11 is formed of four resin films 10, but the number of resin films 10 may be any number greater than or equal to two. Also, although only the IC chip 12 is shown as the inlet, the IC sheet (inlet sheet) may have an inlet other than the IC chip 12, such as an antenna.
Furthermore, at least one of the plurality of resin films 10 may be provided with a hollow portion or a notch by being appropriately cut out according to the shape of the inlet (e.g., IC chip 12) so that the inlet can be properly embedded therein, and the plurality of resin films may be laminated and integrated after the inlet is placed in the hollow portion or the notch. For example, in the example of Fig. 1, of the four resin films 10, the two innermost resin films 10 may be provided with a hollow portion for placing the IC chip 12 therein.

In an inlet sheet such as IC sheet 11, at least one of the multiple resin films 10 may be the above-described film. Therefore, for example, some of the multiple resin films 10 (for example, in the configuration of Figure 1, the resin films provided on both surfaces) may be the above-described film, or all of them may be the above-described film. As described above, the film has high concealing properties, so by using it as part or all of an inlet sheet such as IC sheet 11, it is possible to adequately conceal inlets such as IC chips 12.

The thickness of the inlet sheet (IC sheet) is not particularly limited, but is preferably 100 μm or more and 500 μm or less, more preferably 200 μm or more and 460 μm or less, even more preferably 250 μm or more and 440 μm or less, and even more preferably 280 μm or more and 420 μm or less. By making the inlet sheet thicker than 100 μm, inlets such as IC chips can be properly concealed by the inlet sheet. Furthermore, by making the thickness 500 μm or less, it is possible to thicken parts other than the inlet sheet without making the passport data page or card any thicker than necessary, making it easier to add various functions to the data page or card.

In passports or cards, the inlet sheet may be used as a core sheet, with a laser marking sheet laminated on one or both sides. The laser marking sheet is a sheet on which personal information, etc., is printed using a laser. The personal information is information that identifies the passport or card owner, such as their name, personal ID, or card number.

As described above, the present film allows for good printability on laser marking sheets, so laminating a laser marking sheet on the present film can improve the printability of the laser marking sheet. To further improve the printability of the laser marking sheet, the laser marking sheet is preferably positioned so that it is directly laminated to the present film, but it does not have to be directly laminated to the present film. In other words, the present film and the laser marking sheet may be laminated via another layer.
For example, in the IC sheet 11 having the configuration shown in FIG. 1, the resin film 10 on the surface is made of this film, so that the laser marking sheet can be directly laminated on this film.

The laser marking sheet may consist of a single resin layer, but is preferably a multilayer laminate consisting of multiple resin layers. The laser marking sheet preferably includes a resin layer containing a laser coloring agent, and if it consists of a single resin layer, it is preferable that one of the resin layers contains the laser coloring agent. In the case of a multilayer structure, the laser marking sheet may have, for example, a structure in which surface layers are provided on both sides of a middle layer, and the middle layer may contain the laser coloring agent. The laser marking sheet typically comprises a transparent layer.
The thickness of the laser marking sheet is not particularly limited, but is preferably 15 μm to 400 μm, more preferably 30 μm to 300 μm, even more preferably 40 μm to 250 μm, and even more preferably 60 μm to 200 μm. If the thickness of the laser marking sheet is 15 μm or more, various information can be printed appropriately by laser printing. Furthermore, if the thickness is 400 μm or less, it is possible to prevent the passport or card from being thicker than necessary.

The resin used in each resin layer that makes up the laser marking sheet is not particularly limited and may be polyester resin, polycarbonate resin, or a combination of these. However, from the perspective of laser marking ability, it is preferable to use polycarbonate resin. Details of polyester resin and polycarbonate resin are as described above.

The laser color former used in the laser marking sheet is not particularly limited as long as it has the ability to generate heat when irradiated with a laser beam. It may be a so-called self-coloring color former, which changes color by itself when irradiated with laser beam, or it may be one that does not change color by itself. By generating heat, the laser color former promotes carbonization of the surrounding forming material, improving laser marking properties. Furthermore, when a self-coloring laser color former is used, the color of the laser color former and the color of the carbonized material produced by carbonization of the forming material work synergistically to produce a print that is dark in color and has excellent visibility. When the laser color former is colored, there are no particular limitations on the color, but from the perspective of visibility, it is preferable to use a laser color former that can change color to dark colors including black, navy blue, and brown.

The laser coloring agent may be a metal oxide or a compound other than a metal oxide. The metal oxide is not limited as long as it has a laser coloring effect, and examples thereof include iron oxide, copper oxide, zinc oxide, tin oxide, cobalt oxide, nickel oxide, bismuth oxide, indium oxide, antimony oxide, tungsten oxide, neodymium oxide, mica, hydrotalcite, montmorillonite, and smectite.
Laser coloring agents other than metal oxides may also be used, including metals such as iron, copper, zinc, tin, gold, silver, cobalt, nickel, bismuth, antimony, and aluminum; their salts, such as iron chloride, iron nitrate, iron phosphate, copper chloride, copper nitrate, copper phosphate, zinc chloride, zinc nitrate, zinc phosphate, nickel chloride, nickel nitrate, bismuth subcarbonate, and bismuth nitrate; metal hydroxides, such as magnesium hydroxide, lanthanum hydroxide, nickel hydroxide, and bismuth hydroxide; and metal borides, such as zirconium boride, titanium boride, and lanthanum boride. Among metal borides, hexaborides have near-infrared absorption capabilities, and lanthanum hexaboride is preferred because of its excellent laser light absorption efficiency. Dye-based dyes, such as fluoran-based, phenothiazine-based, spiropyran-based, triphenylmethaphthalide-based, and rhodamine lactam-based leuco dyes, and carbon black may also be used.
As the laser coloring agent, it is preferable to use a bismuth-based metal oxide such as bismuth oxide or a metal oxide containing bismuth and at least one metal selected from Zn, Ti, Al, Zr, Sr, Nd, and Nb.
The laser coloring agent may be used alone or in combination of two or more kinds.

The printing sheet is a sheet on which fixed information is printed before multiple sheets are stacked and integrated. The fixed information is information other than the personal information described above, and is information that does not change regardless of the card or passport. The fixed information is preferably printed on the printing sheet using known ink such as photo- or thermosetting ink. The printing sheet is a colored sheet and may be made of a single-layer resin film or a laminated film made of multiple resin layers.
The printing sheet is a sheet disposed on the outside of the inlet sheet. When a laser marking sheet is provided, the printing sheet may be provided between the inlet sheet and the laser marking sheet.

The printing sheet used in passports or cards may be made from the film described above. Because the printing sheet is made from the film, it has high concealing properties. Therefore, by placing it on the outside of the inlet sheet, even when the inlet cannot be sufficiently concealed by the inlet sheet, the printing sheet can conceal it. Furthermore, when a laser marking sheet is provided, it may be laminated on top of the printing sheet. In such cases, the laser marking ability of the laser marking sheet can be improved as described above.

The protective sheet used in passports or cards, also known as an oversheet, generally constitutes the outermost layer of the data page of a card or passport. Therefore, when a laser marking sheet or a printing sheet is laminated, the protective sheet is preferably laminated on the outside of these sheets. When laminated on the outside of a laser marking sheet, the protective sheet suppresses the so-called "blistering" that occurs when the laser-printed portion is irradiated with laser light. The protective sheet may consist of a single resin layer, or may be a multilayer laminate consisting of multiple resin layers. The resin used for each resin layer constituting the protective sheet is not particularly limited, and may be polyester resin, polycarbonate resin, or a combination of these. However, polycarbonate resin is preferably used from the standpoint of transparency and heat resistance. Details of polyester resin and polycarbonate resin are as described above. The protective sheet typically constitutes a transparent layer.

The layer structure of the data page of a passport or a card is not particularly limited, but may be, for example, any one of the following layer structures (1) to (6).
(1) Protective sheet/laser marking sheet/IC sheet (inlet sheet)/printed sheet/protective sheet (2) Protective sheet/laser marking sheet/IC sheet (inlet sheet)/laser marking sheet/protective sheet (3) Protective sheet/laser marking sheet/printed sheet/IC sheet (inlet sheet)/printed sheet/laser marking sheet/protective sheet (4) Protective sheet/laser marking sheet/printed sheet/IC sheet (inlet sheet)/laser marking sheet/protective sheet (5) Protective sheet/laser marking sheet/IC sheet (inlet sheet)/protective sheet (6) Protective sheet/laser marking sheet/printed sheet/IC sheet (inlet sheet)/protective sheet Of the above, the passport or card preferably has the laminated structure of (1). Note that, in the above laminated structures (1) to (6), structures in which protective sheets are provided on both outermost surfaces are shown, but one or both of the protective sheets may be omitted as appropriate.

In addition, security features such as lenticular printing, hologram printing, and security threads may be provided on passport data pages and cards using special printing methods, and these may be provided as appropriate, for example, between the protective sheet and the laser marking sheet, between the laser marking sheet and the printing sheet, or between the laser marking sheet and the inlet sheet.

A hinge sheet may also be provided in the passport. The hinge sheet serves to firmly bind the data page together with the passport cover or other visa sheets. The hinge sheet may be positioned so that it protrudes from the inlet sheet, for example, so that it is connected to the inlet sheet that constitutes the core sheet. The hinge sheet may also be positioned, for example, between the inlet sheet and a printing sheet, laser marking sheet, or protective sheet, and may be stacked within the data page so that a portion of the hinge sheet protrudes beyond the inlet sheet.

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

The evaluation method is as follows.
(1) Hiding ability (light transmission density)
The light transmission density of the films obtained in each of the Examples and Comparative Examples was measured using a transmission densitometer "341" manufactured by X-Rite Corp. A higher light transmission density indicates higher hiding power.

(2) Laser Printability A card prepared using this film was laser-printed at a reflection density of 64 μm/Step×50% using a CLM-20 manufactured by Nidec Copal Corporation, and the reflection density of the laser-printed area was measured using an eXact manufactured by X-Rite, Inc. A higher reflection density value indicates better laser printability.
The cards used in the laser printability evaluation were prepared as follows using the present films obtained in the Examples and Comparative Examples and the following laser marking sheet. The laser marking sheet was a three-layer sheet with surface layers on both sides of a middle layer. The surface layer was made of 100% polycarbonate resin (PC2) by mass, and the middle layer was made of 99.8% polycarbonate resin (PC2) by mass and 0.2% laser color former. The laser marking sheet had a total thickness of 50 μm, and the thickness ratio of surface layer/middle layer/surface layer was 1/4/1.
The cards were prepared by stacking a laser marking sheet, the present film (15 sheets used in all cases except Comparative Example 2, and 7 sheets used in Comparative Example 2), and a laser marking sheet in this order, and then heat pressing the laminate at 175°C using a heat press machine, and punching the laminate into a card shape (54 mm x 85 mm).

(3) Card Bending Test Cards made using this film were bent in the direction of the short side of the card with a maximum deflection of 15 mm and a test frequency of 0.5 Hz, and the number of times until the card cracked was confirmed, with reference to JIS X 6305. A card that did not crack after 5,000 bendings was rated as "AA," a card that cracked after 1,000 to less than 5,000 bendings was rated as "A," and a card that cracked after less than 1,000 bendings was rated as "B."
The card used in the card bending test was prepared by stacking multiple sheets of the present film to a thickness of 800 μm, and then hot pressing the laminate at 170°C using a hot press machine, and punching the laminate into a card shape (54 mm × 85 mm).

(4) Chip Embeddability Chip embeddability was evaluated by the difference in Vicat softening temperature from the white polycarbonate film of Comparative Example 1, which is commonly used in conventional core sheets. The Vicat softening temperature was measured by using the films obtained in the Examples and Comparative Example 1 as test pieces, placing the test piece on the tip of a needle indenter, applying a specified load, and raising the temperature at a constant heating rate to determine the temperature when the needle indenter penetrated 1 mm into the test piece. The Vicat softening temperature was measured using the A50 method, with a load of 10 N and a heating rate of 50°C/hour. A needle indenter specified in JIS K7206 was used.
When the Vicat softening temperature was lower than that of the white polycarbonate film of Comparative Example 1 and the difference was between 20 and 5°C, the film was rated as "A" because it had excellent IC chip embeddability and could properly embed IC chips inside when used in an IC sheet.

The raw materials used in this example are as follows:
PC1: Bisphenol A homopolycarbonate (interfacial polymerization method), mass average molecular weight: approximately 72,000, melt flow rate (300°C, 1.2 kgf): 4 g/10 min, glass transition temperature: 150°C
PC2: Bisphenol A homopolycarbonate (interfacial polymerization method), mass average molecular weight: approximately 53,000, melt flow rate (300°C, 1.2 kgf): 15 g/10 min, glass transition temperature: 150°C
Filler: Titanium oxide (rutile type, refractive index 2.7)
Antioxidant/heat stabilizer: A phenolic antioxidant (dibutylhydroxytoluene (BHT)) and a phosphorus-based heat stabilizer (tristearyl phosphite) were used in combination at a mass ratio of 1:1.
Heat stabilizer: a mixture of distearyl acid phosphate and monostearyl acid phosphate. Impact modifier: a core-shell type elastomer, "Metablen E-870A" manufactured by Mitsubishi Chemical Corporation.
Laser coloring agent: bismuth-neodymium metal oxide, average particle size 0.8 μm, specific gravity: 8.9 g/cm ³

[Example 1]
The components constituting Layer A were Dran-blended to the formulation shown in Table 1, kneaded using an extruder, and extruded from a two-kind, three-layer multi-manifold die at 255°C as Layer A (surface layer). The components constituting Layer B were Dran-blended to the formulation shown in Table 1, kneaded using an extruder, and extruded from the same die at 255°C as Layer B (middle layer). The extruded laminate, in which the layers were stacked, was quenched with a casting roll at approximately 120°C to obtain a film consisting of surface layer/middle layer/surface layer with a thickness ratio of 1/4/1 and a total thickness of 50 µm.

[Example 2]
The same procedure as in Example 1 was carried out except that the formulations of layers A and B were changed as shown in Table 1 and the extrusion temperature of layers A and B was changed to 235°C.

[Comparative Example 1]
The components constituting Layer A were run-blended in the proportions shown in Table 1, kneaded using an extruder, and extruded from the extruder at 255°C to obtain a film having a thickness of 50 µm and consisting of a single layer of Layer A.

[Comparative Example 2]
The components constituting Layer A were run-blended in the proportions shown in Table 1, kneaded using an extruder, and extruded from the extruder at 290°C to obtain a 100 µm thick film consisting of a single layer of Layer A.

[Comparative Example 3]
The same procedure as in Comparative Example 1 was carried out except that the formulation of Layer A was changed as shown in Table 1.

[Comparative Example 4]
The same procedure as in Example 1 was carried out except that the formulations of layers A and B were changed as shown in Table 1 and the extrusion temperature of layers A and B was changed to 275°C.

As described above, in Examples 1 and 2, by incorporating a large amount of filler into the film, the light transmission density of the film was increased, and it was possible to improve the concealment of inlets such as IC chips. In contrast, in the films of Comparative Examples 1 and 4, although the filler was incorporated, the content was not large, so the light transmission density was low and it was not possible to sufficiently improve the concealment of inlets such as IC chips.
Furthermore, in Examples 1 and 2, when laser printing was performed on a laser marking sheet laminated to the present film, the reflection density value was higher than when printing was performed on a laser marking sheet laminated to the film of Comparative Examples 1 and 4, which did not contain a large amount of filler, due to the presence of a large amount of filler in the present film, thereby improving laser printability.
Furthermore, despite the fact that the present films of Examples 1 and 2 contained a large amount of filler, the incorporation of an impact modifier improved bending resistance. In addition, it is presumed that the excellent chip embeddability was achieved in Examples 1 and 2 because the use of polycarbonate resin as the resin and the reduction in softening and fluidity during heating that would otherwise be caused by the incorporation of a large amount of filler were prevented.
The present film of Example 1 contained additive (X), and the present film of Example 2 used a polycarbonate resin with a low molecular weight that allowed low-temperature extrusion, so foaming was unlikely to occur in the sheet, and the appearance was good.

10 Resin film 11 IC sheet (inlet sheet)
12 IC chip

Claims (11)

A card or passport film containing a resin, a filler, and an impact resistance improver, wherein the content of the filler is 29 % by mass or more, the refractive index of the filler is 2 or more, and the card or passport film is provided with at least a laser marking sheet . The card or passport film according to claim 1, wherein the content of the impact modifier is 1% by mass or more and 30% by mass or less. The card or passport film according to claim 1 or 2, further comprising at least one additive (X) selected from the group consisting of antioxidants and heat stabilizers, the content of the additive (X) being 0.01% by mass or more and 3% by mass or less. 4. The card or passport film according to claim 1 , wherein the filler comprises titanium oxide. 5. The card or passport film according to claim 1 , wherein the resin is at least one selected from the group consisting of polycarbonate resins and polyester resins. a middle layer including the resin and the filler, and two surface layers provided on both sides of the middle layer;
6. The card or passport film according to claim 1 , wherein each of the surface layers contains the resin, the filler, and the impact resistance improver. The card or passport film according to any one of claims 1 to 6 , which is used as a core sheet. An inlet sheet comprising the card or passport film according to any one of claims 1 to 7 . 9. The inlet sheet according to claim 8 , having a thickness of 100 μm or more and 500 μm or less. A card comprising the card or passport film according to any one of claims 1 to 7 , or the inlet sheet according to claim 8 or 9 . A passport comprising the card or passport film according to any one of claims 1 to 7 , or the inlet sheet according to claim 8 or 9 .