JP7257596B1 - Films and multilayer films - Google Patents

Abstract

To provide a film and a multilayer film which are excellent in slidability and can suppress the generation of air bubbles when they are bonded to other substrates and heated. A film containing 0.005 to 0.5 parts by mass of a layered clay mineral with respect to 100 parts by mass of a polycarbonate resin, having a surface roughness Sa of 10 to 100 nm and a thickness of 50 to 200 μm. ,the film.

Description

The present invention relates to films and multilayer films.

Polycarbonate resins are used in various applications because of their superior transparency, workability and impact resistance compared to glass. As an example thereof, applications as various films are known, and are described in Patent Document 1, for example.

In some cases, films are required to have slidability to the extent that they do not stack, and to suppress adhesion between films (anti-blocking properties) from the viewpoint of improving transportability and preventing winding wrinkles. Here, anti-blocking means that films can be easily peeled off even if they are in close contact with each other. In order to impart slidability to the film, it is conceivable to provide fine unevenness on the surface of the film. By forming fine irregularities on the surface of the film in this manner, the contact area between the films is reduced, and high slidability is achieved.

WO2020/241671

On the other hand, the film may be laminated with another substrate and heated. Such films are often produced industrially by roll-to-roll. It is preferably used from the viewpoint of prevention and the like. However, it has been found that if the surface has fine irregularities, air bubbles may be generated when the substrate is bonded to another base material and heated.
An object of the present invention is to solve such problems, and to provide a film and a multilayer film that are excellent in slidability and that can suppress the generation of air bubbles when heated while being laminated with another base material. for the purpose.

Based on the above-mentioned problem, the present inventors conducted studies and found that the above-mentioned problem was solved by using a layered clay mineral and adjusting the surface roughness Sa of the film within a predetermined range.
Specifically, the above problems have been solved by the following means.
<1> A film containing 0.005 to 0.5 parts by mass of a layered clay mineral with respect to 100 parts by mass of a polycarbonate resin, wherein the surface roughness Sa of the film is 10 to 100 nm, and the thickness of the film is A film that is between 50 and 200 μm.
<2> The film according to <1>, wherein the layered clay mineral has an average long side and short side of 2.0 μm to 9.0 μm.
<3> The film according to <1> or <2>, wherein the layered clay mineral has a refractive index of 1.55 to 1.63.
<4> The film according to any one of <1> to <3>, wherein the layered clay mineral contains mica.
<5> The film according to any one of <1> to <4>, wherein the film has a haze of 2% or less under a D65 light source of 10° field of view.
<6> The film according to any one of <1> to <5>, which is a substrate for a protective film.
<7> A multilayer film comprising the film according to any one of <1> to <6> and another layer.
<8> The multilayer film according to <7>, wherein the other layer has an adhesive layer.
<9> A transparent conductive film having a protective layer, an adhesive layer, a substrate, and an electrode layer in this order, wherein the protective layer is any one of <1> to <6> A transparent conductive film, which is the film described.

ADVANTAGE OF THE INVENTION By this invention, it became possible to provide the film which is excellent in slidability, and can suppress generation|occurrence|production of an air bubble, when bonding with another base material and heating, and a multilayer film.

BRIEF DESCRIPTION OF THE DRAWINGS It is the schematic which shows an example of the multilayer film of this embodiment.

EMBODIMENT OF THE INVENTION Hereinafter, the form (only henceforth "this embodiment") for implementing this invention is demonstrated in detail. In addition, the following embodiment is an example for explaining the present invention, and the present invention is not limited only to this embodiment.
In this specification, the term "~" is used to mean that the numerical values before and after it are included as the lower limit and the upper limit.
In this specification, various physical property values and characteristic values are at 23° C. unless otherwise specified.
In the description of a group (atomic group) in the present specification, a description that does not describe substitution or unsubstituted includes a group (atomic group) having no substituent as well as a group (atomic group) having a substituent. For example, an "alkyl group" includes not only an alkyl group having no substituent (unsubstituted alkyl group) but also an alkyl group having a substituent (substituted alkyl group). In this specification, the notations that do not describe substituted and unsubstituted are preferably unsubstituted.
As used herein, the term "process" includes not only an independent process, but also when the intended action of the process is achieved even if it cannot be clearly distinguished from other processes. .
As used herein, the term "film" refers to a generally flat molded body that is thin in thickness relative to its length and width. In addition, the term "film" in this specification is intended to include "sheet". Also, the "film" may be a single layer or multiple layers.
If the measurement methods, etc. described in the standards shown in this specification differ from year to year, they shall be based on the standards as of January 1, 2021 unless otherwise stated.

The film of the present embodiment contains 0.005 to 0.5 parts by mass of layered clay mineral with respect to 100 parts by mass of polycarbonate resin, has a surface roughness Sa of 10 to 100 nm, and has a thickness of 50 to 200 μm. It is characterized by
With such a configuration, it is possible to provide a film, a multilayer body, and a protective film that are excellent in slidability and that can suppress the generation of air bubbles when the film is laminated to another base material and heated.

It is presumed that air bubbles generated when the film is laminated to other substrates originate from the air present in the space formed by the unevenness of the film surface. Spaces larger than a certain size tend to create regions where air enters when they are laminated, and when such spaces concentrate, it is speculated that these regions become starting points, and air bubbles are generated as air gathers. From this, it is considered that, for example, when there are many small unevennesses, it is difficult for air to enter the space formed by the small unevennesses, and therefore, it is unlikely to become a starting point for the formation of air bubbles. In the present embodiment, Sa is selected as an index representing the unevenness of the surface on which air is difficult to collect, Sa as an index that comprehensively indicates the number, density, and height or depth of unevenness on the film surface. examined carefully. As a result, it was found that generation of air bubbles can be effectively suppressed by adjusting Sa to 10 to 100 nm. As a result, it has become possible to provide a film that has excellent slidability and that can suppress the generation of air bubbles.
Furthermore, in the present embodiment, by forming unevenness using a layered clay mineral, slidability can be imparted more effectively. That is, by using the layered clay mineral, which is a particle with a relatively sharp shape, it is easier to form sharper irregularities than when spherical particles are used, effectively imparting a coefficient of dynamic friction, and sliding. Mobility tends to improve. Further, for example, when there are high convex portions locally, it is difficult to improve the slidability, and it is necessary that the entire surface of the film is provided with moderate unevenness.
Details of the present embodiment will be described below.

<Surface roughness Sa>
In the film of this embodiment, Sa is 10 to 100 nm. In the film of the present embodiment, at least one surface should satisfy Sa, but both surfaces may satisfy Sa. When both sides satisfy the above Sa, the Sa on one side and the Sa on the other side may be the same or different.
Sa is an index that comprehensively indicates the number, density, and height or depth of unevenness on the film surface. By adjusting Sa to 10 to 100 nm, it is possible to obtain a film that has excellent slidability and that can suppress the generation of air bubbles when bonded to another substrate.
Sa can be adjusted not only by adjusting the size and amount of the layered clay mineral and the thickness of the film, but also by adjusting the manufacturing conditions. In particular, when a film is produced by roll-to-roll, it can be adjusted by adjusting the temperature, the surface hardness of the roll, the speed of the roll, the amount of discharge during extrusion, and the like. Note that Sa may be adjusted by combining two or more of these means.
The lower limit of Sa is preferably 20 nm or more, more preferably 25 nm or more, still more preferably 27 nm or more, still more preferably 30 nm or more, and even more preferably 40 nm or more. Preferably, it is more preferably 50 nm or more. By making it more than the said lower limit, it can provide moderate unevenness|corrugation in the film surface, and there exists a tendency for a slidability to improve more. The upper limit of Sa is preferably 90 nm or less, more preferably 80 nm or less, even more preferably 70 nm or less, and even more preferably 60 nm or less. By making it below the said upper limit, generation|occurrence|production of a bubble can be suppressed effectively.
Sa is measured by the method described in Examples below.

<Film thickness>
The film of this embodiment has a thickness of 50 to 200 μm. By setting the thickness to 200 μm or less, the layered clay mineral is easily exposed on the surface, and slidability can be achieved. Furthermore, the windability of the film can be improved. Further, by setting the thickness to 50 μm or more, the layered clay mineral is not exposed too much on the surface, and the effect of increasing the transparency of the film is obtained.
The thickness of the film of the present embodiment is preferably 60 μm or more, more preferably 70 μm or more, still more preferably 80 μm, and even more preferably 90 μm. Also, it is preferably 180 μm or less, more preferably 150 μm or less, and even more preferably 120 μm or less.
In particular, when a film having the above thickness is formed, it is excellent in windability.
Let the thickness of a film be the average value of five arbitrary places.

<Other properties of the film>
In the film of the present embodiment, the dynamic friction coefficient of at least one surface with respect to a film having a root mean square roughness of 0.093 μm is preferably 2.00 or less, more preferably 1.80 or less. It is preferably 1.50 or less, even more preferably 1.20 or less, and may be 1.00 or less. When the coefficient of dynamic friction is 2.00 or less, the slidability tends to be excellent. Although the lower limit is not particularly defined, it is, for example, 0.10 or more, and may be 0.20 or more, 0.30 or more, 0.40 or more, or 0.50 or more.
The coefficient of dynamic friction is a value measured under the conditions of a thread of 100 mm/min and a load cell of 10 N. Specifically, it is measured by the method described in the examples below.

The film of the present embodiment preferably has a total light transmittance of 86.0% or more, more preferably 87.0% or more, and more preferably 89.0% or more under the condition of D65 light source 10° field of view. It is more preferably 90.0% or more. The upper limit of the light transmittance is ideally 100%, but even if it is 95.0% or less, the required performance is sufficiently satisfied.
The total light transmittance is measured by the method described in Examples below.

The film of the present embodiment preferably has a haze of 2.0% or less, more preferably 1.8% or less, and may be 1.5% or less under the condition of a D65 light source of 10° field of view. It may be 1.0% or less. As for the lower limit, 0% is ideal, but even 0.1% or more is a practical level.
Haze is measured by the method described in Examples below.

<Polycarbonate resin>
The film of this embodiment contains a polycarbonate resin. A film having excellent transparency can be obtained by using a polycarbonate resin.
The polycarbonate resin used in the present embodiment is a -[OR-OC(=O)]-unit containing a carbonate bond in the molecular main chain (R is a hydrocarbon group, specifically an aliphatic group, It is not particularly limited as long as it contains an aromatic group, or a group containing both an aliphatic group and an aromatic group, or a group having a linear or branched structure. In the present embodiment, the polycarbonate resin is preferably an aromatic polycarbonate resin, more preferably a polycarbonate resin having a bisphenol skeleton. By using such a polycarbonate resin, better heat resistance and toughness can be achieved. In the present embodiment, it is preferable that 90 mol % or more of all structural units in the polycarbonate resin having a bisphenol skeleton are structural units having a bisphenol skeleton.

Further, the viscosity average molecular weight (Mv) of the polycarbonate resin is preferably 10,000 or more, more preferably 12,000 or more, still more preferably 15,000 or more, and still more preferably 18,000. That's it. When the content is at least the above lower limit, the durability of the substrate tends to be further improved. The upper limit of the viscosity average molecular weight (Mv) of the polycarbonate resin is preferably 50,000 or less, more preferably 40,000 or less, and even more preferably 30,000 or less. When the content is equal to or less than the above upper limit, the moldability of the substrate tends to be further improved.
The viscosity-average molecular weight (Mv) is determined by using methylene chloride as a solvent and using an Ubbelohde viscometer to determine the intrinsic viscosity [η] (unit: dL/g) at a temperature of 25°C. 1.23×10 ⁻⁴ ×Mv ^0.83 means a value calculated from.
When two or more polycarbonate resins are used, the viscosity-average molecular weight of the mixture is used.

The refractive index of the polycarbonate resin is preferably 1.56 or more, more preferably 1.58 or more, and preferably 1.63 or less, more preferably 1.60 or less. preferable. When the content is at least the above lower limit, the difference in refractive index from the layered clay mineral tends to be small and the transparency tends to be improved. By making it equal to or less than the above upper limit, there is a tendency that the difference in refractive index from the layered clay mineral becomes small and the transparency is improved.
The difference in refractive index between the polycarbonate resin and the layered clay mineral is preferably 0.05 or less, more preferably 0.04 or less, even more preferably 0.03 or less, and further preferably 0.05 or less. 02 or less is even more preferable, 0.015 is even more preferable, 0.012 or less is particularly preferable, and 0.01 or less is even more preferable. Ideally, the refractive index difference is zero. By reducing the difference in refractive index, the transparency of the film of the present embodiment can be further improved.
The refractive index of polycarbonate resin can be measured according to the JIS K7142A method.

The content of the polycarbonate resin in the film of the present embodiment is preferably 95% by mass or more, more preferably 97% by mass or more, and may be 99% by mass or more of the entire film. The upper limit of the polycarbonate resin content is a value at which the total content of the polycarbonate resin and the layered clay mineral is 100% by mass of the entire film.
The film of the present embodiment may contain only one type of polycarbonate resin, or may contain two or more types. When two or more types are included, the total amount is preferably within the above range.

式（Ａ－１）中、Ｘ^１は下記構造を表す。式中の＊は結合位置を表す。

Ｒ^５およびＲ^６は、少なくとも一方がメチル基であることが好ましく、両方がメチル基であることがより好ましい。
式（Ａ－１）は下記式（Ａ－２）で表されることが好ましい。

A first embodiment of the polycarbonate resin in this embodiment is a polycarbonate resin having a structural unit represented by formula (A-1), and a typical example thereof is a bisphenol A type polycarbonate resin.

In formula (A-1), X ¹ represents the following structure. * in the formula represents a binding position.

At least one of R ⁵ and R ⁶ is preferably a methyl group, more preferably both are methyl groups.
Formula (A-1) is preferably represented by the following formula (A-2).

In the polycarbonate resin of the first embodiment, the content of the structural unit represented by formula (A-1) is preferably 70 mol% or more, 80 mol% or more, of all structural units excluding terminal groups. and more preferably 90 mol % or more. The upper limit is not particularly limited, and 100 mol % may be the structural unit represented by formula (A-1).
The polycarbonate resin may have other structural units. Examples of dihydroxy compounds that constitute such other structural units include aromatic dihydroxy compounds described in paragraph 0014 of JP-A-2018-154819, the contents of which are incorporated herein. .

式（Ａ－３）中、Ｒ^１１～Ｒ^１４は、それぞれ独立に、フッ素原子、塩素原子、臭素原子、ヨウ素原子、炭素数１～９（好ましくは１～３）のアルキル基、炭素数６～１２（好ましくは６～１０）のアリール基、炭素数１～５（好ましくは１～３）のアルコキシ基、炭素数２～５（好ましくは２または３）のアルケニル基または炭素数７～１７（好ましくは７～１１）のアラルキル基を表す。ｌは０～５の整数（好ましくは０または１、より好ましくは０）を表す。ｍおよびｎはそれぞれ独立に０～４の整数（好ましくは０または１、より好ましくは０）を表す。式中の＊は他の構成単位や末端基との結合位置を表す。A second embodiment of the polycarbonate resin in this embodiment is a polycarbonate resin containing a structural unit represented by formula (A-3), and a typical example thereof is a bisphenol AP type polycarbonate resin.

In formula (A-3), R ¹¹ to R ¹⁴ each independently represent a fluorine atom, a chlorine atom, a bromine atom, an iodine atom, an alkyl group having 1 to 9 carbon atoms (preferably 1 to 3 carbon atoms), and 6 carbon atoms. -12 (preferably 6-10) aryl group, 1-5 (preferably 1-3) alkoxy group, 2-5 (preferably 2 or 3) alkenyl group or 7-17 carbon atoms represents an aralkyl group (preferably 7 to 11). l represents an integer of 0 to 5 (preferably 0 or 1, more preferably 0). m and n each independently represent an integer of 0 to 4 (preferably 0 or 1, more preferably 0). * in the formula represents the bonding position with other structural units or terminal groups.

Ｒ^１１、Ｒ^１２、Ｒ^１３、Ｒ^１４、ｌ、ｍ、ｎは、式（Ａ－３）で定義したものと同義である。The structural unit represented by formula (A-3) is preferably a structural unit represented by formula (A-4) below. * in the formula represents the bonding position with other structural units or terminal groups.

R ¹¹ , R ¹² , R ¹³ , R ¹⁴ , l, m and n have the same meanings as defined in formula (A-3).

The structural unit represented by formula (A-4) is preferably a structural unit represented by formula (A-5) below. * in the formula represents the bonding position with other structural units or terminal groups.

In the polycarbonate resin of the second embodiment, the content of the structural unit represented by formula (A-3) is preferably 70 mol% or more, 80 mol% or more, of all structural units excluding terminal groups. and more preferably 90 mol % or more. The upper limit is not particularly limited, and 100 mol % may be the structural unit represented by formula (A-3).
The polycarbonate resin may have other structural units. Examples of other structural units include structural units represented by the above formula (A-1) and structural units derived from aromatic dihydroxy compounds described in paragraph 0014 of JP-A-2018-154819. The contents are incorporated herein.

式（Ａ－６）中、Ｒ^８は、それぞれ独立に、フッ素原子、塩素原子、臭素原子、ヨウ素原子、炭素数１～９（好ましくは１～３）のアルキル基、炭素数６～１２（好ましくは６～１０）のアリール基、炭素数１～５（好ましくは１～３）のアルコキシ基、炭素数２～５（好ましくは２または３）のアルケニル基または炭素数７～１７（好ましくは７～１１）のアラルキル基を表す。ｑは０～５の整数（好ましくは１～３の整数）を表し、１～３の整数が好ましい。式中の＊は他の構成単位や末端基との結合位置を表す。
Ｒ^８は、それぞれ独立に、炭素数１～９（好ましくは１～３）のアルキル基が好ましく、メチル基がより好ましい。A third embodiment of the polycarbonate resin in the present embodiment is a polycarbonate resin having a structural unit represented by the following formula (A-6), and representative examples thereof include bisphenol Z-type polycarbonate resin and bisphenol TMC. type polycarbonate resin.

In formula (A-6), R ⁸ each independently represents a fluorine atom, a chlorine atom, a bromine atom, an iodine atom, an alkyl group having 1 to 9 carbon atoms (preferably 1 to 3), 6 to 12 carbon atoms ( an aryl group having preferably 6 to 10), an alkoxy group having 1 to 5 carbon atoms (preferably 1 to 3), an alkenyl group having 2 to 5 carbon atoms (preferably 2 or 3) or 7 to 17 carbon atoms (preferably 7 to 11) represents an aralkyl group. q represents an integer of 0-5 (preferably an integer of 1-3), preferably an integer of 1-3. * in the formula represents the bonding position with other structural units or terminal groups.
R ⁸ is each independently preferably an alkyl group having 1 to 9 carbon atoms (preferably 1 to 3 carbon atoms), more preferably a methyl group.

式（Ａ－７）中、Ｒ^８は式（Ａ－６）におけるＲ^８と同義であり、好ましい範囲も同様である。
また、式（Ａ－６）で表される構成単位の他の好ましい形態としては、ｑが０であること挙げられる。The structural unit represented by formula (A-6) is preferably a structural unit represented by formula (A-7) below. * in the formula represents the bonding position with other structural units or terminal groups.

In formula (A-7), R ⁸ has the same definition as R ⁸ in formula (A-6), and the preferred range is also the same.
Another preferred form of the structural unit represented by formula (A-6) is that q is 0.

In the polycarbonate resin of the third embodiment, the content of the structural unit represented by formula (A-6) is preferably 70 mol% or more, 80 mol% or more, of all structural units excluding terminal groups. and more preferably 90 mol % or more. The upper limit is not particularly limited, and 100 mol % may be the structural unit represented by formula (A-6).
The polycarbonate resin may have other structural units. Other structural units include structural units represented by the above formula (A-1), structural units represented by the above formula (A-3), and aromatic compounds described in paragraph 0014 of JP-A-2018-154819. Building blocks derived from dihydroxy compounds can be mentioned, the contents of which are incorporated herein.

（式（Ａ－８）中、Ｒ^２１は、炭素数８～３６のアルキル基、または、炭素数８～３６のアルケニル基を表し、Ｒ^２２は、ハロゲン原子、炭素数１～２０のアルキル基、または、炭素数６～１２のアリール基を表し、ｎ２は０～４の整数である。）A fourth embodiment of the polycarbonate resin in this embodiment is a polycarbonate resin having a terminal structure represented by formula (A-8).

(In formula (A-8), R ²¹ represents an alkyl group having 8 to 36 carbon atoms or an alkenyl group having 8 to 36 carbon atoms, and R ²² represents a halogen atom or an alkyl group having 1 to 20 carbon atoms. , or represents an aryl group having 6 to 12 carbon atoms, and n2 is an integer of 0 to 4.)

R ²¹ is preferably an alkyl or alkenyl group having 12 or more carbon atoms, more preferably an alkyl or alkenyl group having 14 or more carbon atoms. R ²¹ is preferably an alkyl or alkenyl group having 22 or less carbon atoms, more preferably an alkyl or alkenyl group having 18 or less carbon atoms. R ²¹ is preferably an alkyl group.
R ²² is preferably a fluorine atom, a chlorine atom, a methyl group, an ethyl group or a phenyl group, preferably a fluorine atom, a chlorine atom or a methyl group.
n2 is preferably an integer of 0 to 2, more preferably 0 or 1, even more preferably 0.

The terminal structure represented by formula (A-8) can be added to the polycarbonate resin by using a terminal terminator. These details can be referred to paragraphs 0022 to 0030 of Japanese Patent Application Laid-Open No. 2019-002023, and the contents thereof are incorporated herein.

The molecular main chain in the polycarbonate resin of the fourth embodiment comprises -[OR-OC(=O)]-units (R is a hydrocarbon group, specifically an aliphatic group, an aromatic group, or , those containing both an aliphatic group and an aromatic group, and those having a linear or branched structure) are not particularly limited. The polycarbonate resin of the fourth embodiment is preferably an aromatic polycarbonate resin, more preferably a polycarbonate resin having a bisphenol skeleton, more preferably a polycarbonate resin having a structural unit represented by the above formula (A-1), and bisphenol A type polycarbonate resins are more preferred. By using such a polycarbonate resin, better heat resistance and toughness can be achieved. In the polycarbonate resin having a bisphenol skeleton, 90 mol % or more of all structural units excluding terminal structures are preferably structural units having a bisphenol skeleton.

The method for producing the polycarbonate resin is not particularly limited, and any method can be adopted. Examples thereof include an interfacial polymerization method, a melt transesterification method, a pyridine method, a ring-opening polymerization method of a cyclic carbonate compound, a solid-phase transesterification method of a prepolymer, and the like.

<Layered clay mineral>
The film of this embodiment contains 0.005 to 0.5 parts by mass of the layered clay mineral with respect to 100 parts by mass of the polycarbonate resin. With such a structure, the Sa of the film surface can be adjusted appropriately, the slidability is achieved, and air bubbles generated when the film is laminated to another base material and heated can be effectively suppressed. can. Furthermore, by using the layered clay mineral, which is a particle with a relatively sharp shape, it is easier to form sharper irregularities than when spherical particles are used, effectively imparting a coefficient of dynamic friction and sliding. Mobility tends to improve.
The layered clay mineral in this embodiment is a layered silicate formed from a magnesium silicate layer or an aluminum silicate layer, and cations are adsorbed between the layers. Cations are typically metal ions such as sodium ions, potassium ions, calcium ions. Examples include smectite, montmorillonite, hectorite, saponite, vermiculite, talc, virophyllite, mica, mica, magadiite, islarite, and kanemite, and both natural and synthetic materials can be used. In the present embodiment, talc, mica, and mica are preferred, talc and mica are more preferred, and mica is even more preferred. By using mica, the difference in refractive index from polycarbonate resin is small, and transparency can be improved.
When the layered clay mineral is mica, the mica is exemplified by white mica and gold mica, preferably white mica.

The average value (A) of the long side and short side of the layered clay mineral is preferably 2.0 μm to 9.0 μm. The average value of the long side and short side (A) was obtained by randomly extracting 100 layered clay minerals observed with a scanning electron microscope, and measuring the length of the surface forming the layer for each particle, that is, the surface with the maximum area. The average value (B) of the sides and short sides is measured, and the average value (A) is calculated from the average values (B) of 100 long sides and short sides. The term "surface" used herein is meant to include what is regarded as one surface of the layered clay mineral in the technical field of the present invention, in addition to the geometric meaning of the "surface". The long side is the side corresponding to the major axis when the surface of the particle is approximated to an ellipse, and the short side is the side corresponding to the minor axis when the surface of the particle is approximated to be elliptical.
The average value of the long side and short side of the layered clay mineral is preferably 2.0 μm or more, more preferably 2.5 μm or more, further preferably 3.0 μm or more, and 4.0 or more. is more preferable. When the content is equal to or higher than the above lower limit, there is an effect of further enhancing the slidability of the film. The average value of the long side and the short side of the layered clay mineral is preferably 9.0 μm or less, more preferably 8.5 μm or less. When the thickness is equal to or less than the above upper limit, it is possible to more effectively suppress the generation of air bubbles when the film is adhered to another base material and heated.
The film of the present embodiment may contain only one type of layered clay mineral, or may contain two or more types. When two or more types are included, it is preferable that the average value (A) of the long side and the short side when measured as a mixture by the above method falls within the above range.
The thickness of the layered clay mineral is preferably 0.1 μm or more, and may be 0.3 μm or more, 0.5 μm or more, or 1.0 μm or more. It may be 5 μm or more. Further, it is preferably 9.0 μm or less, may be 7.0 μm or less, may be 5.0 μm or less, may be 3.0 μm or less, or may be 2.0 μm or less. .

The layered clay mineral preferably has a refractive index of 1.55 to 1.63. This tends to improve the transparency of the resulting film.
The refractive index is preferably 1.56 or more, more preferably 1.57 or more, and even more preferably 1.58 or more. The refractive index is preferably 1.62 or less, more preferably 1.61 or less, even more preferably 1.60 or less, and even more preferably 1.59 or less. , 1.58 or less.
The refractive index is measured by the method described in Examples below.

The content of the layered clay mineral is 0.005 to 0.5 parts by mass with respect to 100 parts by mass of the polycarbonate resin. Sliding property can be achieved by making it more than the said lower limit. Further, by setting the thickness to the above upper limit or less, it is possible to effectively suppress the generation of air bubbles when heating is performed while bonding to another base material. Furthermore, the transparency can be further improved.
The content of the layered clay mineral is preferably 0.01 parts by mass or more, more preferably 0.02 parts by mass or more, and 0.03 parts by mass or more with respect to 100 parts by mass of the polycarbonate resin. It may be 0.04 parts by mass or more. In addition, the content of the layered clay mineral is preferably 0.40 parts by mass or less, more preferably 0.30 parts by mass or less, and 0.20 parts by mass or less with respect to 100 parts by mass of the polycarbonate resin. , more preferably 0.10 parts by mass or less, and even more preferably 0.08 parts by mass or less.

The content of the layered clay mineral is preferably 0.005% by mass or more, more preferably 0.01% by mass or more, and 0.02% by mass or more relative to the total mass of the film. is more preferable, and may be 0.03% by mass or more, or may be 0.04% by mass or more. The content of the layered clay mineral is preferably 0.40% by mass or less, more preferably 0.30% by mass or less, and 0.20% by mass or less, relative to the total mass of the film. Certain things are more preferable, and 0.10% by mass or less is more preferable, and 0.08% by mass or less is even more preferable.
The film of the present embodiment may contain only one type of layered clay mineral, or may contain two or more types. When two or more types are included, the total amount is preferably within the above range.

The film of the present embodiment may or may not contain particles (organic particles and inorganic particles) other than the layered clay mineral. It is preferable that the layered clay mineral does not substantially contain particles other than the layered clay mineral. "Substantially free of particles other than the layered clay mineral" means that the content of particles other than the layered clay mineral is 10% by mass or less of the content of the layered clay mineral used in the present embodiment. It is preferably 5% by mass or less, more preferably 3% by mass or less, even more preferably 1% by mass or less, and even more preferably 0.1% by mass or less.

<Other ingredients>
The film of the present embodiment may contain other components in addition to the polycarbonate resin and the layered clay mineral within the scope of the present invention. Specifically, release agents, antioxidants, transesterification inhibitors, heat stabilizers, flame retardants, flame retardant aids, ultraviolet absorbers, colorants, antistatic agents, fluorescent brighteners, antifogging agents, Fluidity improvers, plasticizers, dispersants, antibacterial agents, antiblocking agents, impact modifiers, sliding modifiers, hue modifiers, acid trapping agents and the like may also be included. These components may be used alone or in combination of two or more.
Moreover, the film of the present embodiment may have a structure that does not substantially contain resin components other than the polycarbonate resin. “Substantially free” means that the content of resin components other than the polycarbonate resin is less than 1 part by mass in 100 parts by mass of the resin components contained in the film of the present embodiment.

For details of the release agent, the release agent described in paragraph 0032 of JP-A-2017-226848 and paragraph 0056 of JP-A-2018-199745 can be used, the contents of which are incorporated herein.
Details of the antioxidant can be referred to paragraphs 0057 to 0061 of JP-A-2017-031313, the contents of which are incorporated herein.
Details of the transesterification inhibitor can be referred to paragraphs 0035 to 0039 of International Publication No. 2015/190162, paragraph 0037 of JP-A-2019-002023, and paragraph 0041 of JP-A-2018-199745. The contents are incorporated herein.

<Film manufacturing method>
A known manufacturing method can be adopted as the method for manufacturing the film of the present embodiment. For example, after melt-kneading the polycarbonate resin, the layered clay mineral, and other ingredients blended as necessary, the mixture may be extruded in the form of a film. Furthermore, roll-to-roll manufacturing is preferred.

<Wound body>
The film of the present embodiment can be a wound body wound around a core material. The film of the present embodiment can be controlled to have a take-up tension of 200 N, for example, and can be wound on a paper tube with an inner diameter of 3 inches for 30 m or more without using a masking film.

<Multilayer film>
The film of the present embodiment may be a single layer film or a multilayer film composed of a plurality of resin layers. The film of this embodiment can be used as a multilayer film containing the above film and at least one other layer. A known layer can be employed as the other layer.
By manufacturing a single-layer film and then laminating other layers, the unevenness of the surface of the film can be properly maintained. As the other layer, a known layer can be adopted, and an adhesive layer is exemplified. That is, as an example of application of the film of the present embodiment, there is an adhesive sheet for lamination having the film of the present embodiment and an adhesive layer.
The multilayer film of this embodiment may or may not have a hard coat layer. The multilayer film of the present embodiment preferably does not have a hard coat layer. The multi-layer film of the present embodiment is highly valuable in that a film with high slidability can be achieved even without a hard coat layer.

<Adhesive layer>
The type of adhesive layer is not particularly limited, but it preferably contains at least one of an acrylic adhesive, a silicone adhesive and a urethane adhesive. By using these adhesives, higher adhesiveness and, for example, moderate adhesion to the primer layer can be achieved.
In addition, the adhesive layer may have re-peelability, and the adhesive layer having re-peelability can be re-adhered even if it is once peeled from the pasting material.
Details of the adhesive layer can be referred to paragraphs 0046 to 0051 of WO 2021/029283, the contents of which are incorporated herein.

The acrylic pressure-sensitive adhesive is a pressure-sensitive adhesive containing an acrylic polymer, and specific examples thereof include DIC's Fine Tack (CT-3088, CT-3850, CT-6030, CT-5020, CT-5030), Quick Master (SPS-900-IV, Quickmaster SPS-1040NT-25), and the adhesive Oripine manufactured by Toyochem.
A silicone pressure-sensitive adhesive is a pressure-sensitive adhesive containing a silicone-based polymer, and specific examples thereof include polymers manufactured by Shin-Etsu Chemical Co., Ltd. KR-3700 (main agent) and CAT-PL-50T (platinum catalyst). mentioned.
A urethane adhesive is an adhesive containing a urethane-based polymer, and specific examples thereof include the adhesive Oripine manufactured by Toyochem Co., Ltd., and the like.
As used herein, a polymer means a compound having a number average molecular weight of 1,000 or more, preferably 2,000 or more.

As the adhesive layer, in addition to the above, within the scope of the present invention, the adhesive layer described in paragraphs 0026 to 0053 of JP 2017-200975, paragraphs 0056 to 0060 of JP 2013-020130 The adhesive layer described in, the adhesive sheet of International Publication No. 2016/158827, the adhesive layer of paragraphs 0031 to 0032 of JP-A-2016-182791, the rubber-based adhesive of paragraphs 0057 to 0084 of JP-A-2015-147837 Agent layers can also be employed, the contents of which are incorporated herein.

The thickness of the adhesive layer is not particularly limited, but is preferably 10 μm or more, more preferably 20 μm or more, even more preferably 25 μm or more, and may be 28 μm or more. Also, the thickness of the adhesive layer is preferably 70 μm or less, more preferably 60 μm or less. By setting it within the above range, more appropriate adhesive properties and adhesive strength are achieved.

<Primer layer>
The adhesive sheet of the present invention may have a primer layer as described above. The primer layer is provided between the base material layer and the adhesive layer, and has the effect of increasing the adhesion between the adhesive layer and the base material layer. In addition, it is possible to suppress chemical cracks in the base material due to the solvent used when forming the adhesive layer.
The primer layer preferably contains a urethane (meth)acrylate resin. By using a urethane (meth)acrylate resin, a pressure-sensitive adhesive sheet with more excellent heat resistance can be obtained.
Details of the primer layer can be referred to in paragraphs 0052 to 0070 of WO2021/029283, the contents of which are incorporated herein.

<Method for manufacturing adhesive sheet>
In the production of the pressure-sensitive adhesive sheet, it is preferred that the substrate (film) is formed first.
The pressure-sensitive adhesive sheet can be produced using the base material (film) containing the above-described polycarbonate, for example, by a method including a primer layer forming step and an adhesive layer forming step, as described below.
In the primer layer forming step, a primer coating (primer liquid) is applied onto the surface of the substrate and cured to form a primer layer.
In the adhesive layer forming step, an adhesive is applied to the surface of the formed primer layer opposite to the side in contact with the base material and cured to form an adhesive layer.
Techniques such as photocuring and heat curing can be employed as techniques for curing the primer paint or adhesive.

The adhesive sheet for lamination of the present embodiment can be used for image display devices such as mobile phone terminals, smartphones, portable electronic playground equipment, personal digital assistants, tablet devices, mobile personal computers, wearable terminals, liquid crystal televisions, liquid crystal monitors, desktop personal computers, cars, etc. It can be used as a constituent material for various elements such as navigation devices, automobile instruments, and installation-type display devices. In particular, it can be suitably used as a transparent conductive film of the liquid crystal member, a substrate material for various elements, and a protective material.
More specifically, the film of this embodiment is preferably used as a masking film. More preferably, it is used as an antiblocking film. It is also preferably used as a protective film for transparent conductive films. In particular, a transparent conductive film having a protective layer, an adhesive layer, a substrate, and an electrode layer in this order, wherein at least one of the substrate and the protective layer (preferably at least the protective layer) It is preferably used as a transparent conductive film, which is a film of the form. As for the transparent conductive film, the description in JP-A-2018-152187 can be referred to, and the contents thereof are incorporated herein.
Moreover, the transparent conductive film is preferably used as a transparent conductive film used for film sensors of touch panels, electronic paper, dye-sensitized solar cells, touch sensors, and the like.

<Application>
The film of the present embodiment is preferably used as a substrate for a protective film because it has excellent slidability and can suppress the generation of air bubbles when it is attached to another substrate and heated. Furthermore, since the film of the present embodiment is also excellent in transparency, it can be preferably used in a case where an in-line defect inspection is performed with a protective film attached.
In addition to the above, the film of the present embodiment is preferably used as a film for applications that require slidability and suppression of bubble generation.

EXAMPLES The present invention will be described more specifically with reference to examples below. The materials, usage amounts, ratios, processing details, processing procedures, etc. shown in the following examples can be changed as appropriate without departing from the gist of the present invention. Accordingly, the scope of the present invention is not limited to the specific examples shown below.
If the measuring instruments and the like used in the examples are discontinued and difficult to obtain, other instruments having equivalent performance can be used for measurement.

1. Raw material polycarbonate resin A1: Bisphenol A type polycarbonate resin Iupilon E-2000 manufactured by Mitsubishi Engineering-Plastics, viscosity average molecular weight: 27000, refractive index: 1.59

Layered clay mineral B1: Mearlmica SV, mica, manufactured by BASF, average value of long and short sides (A): 8.0 μm, refractive index: 1.58
B2: Mearlmica FF, mica, manufactured by BASF, average value of long side and short side (A): 4.2 μm, refractive index: 1.58
B3: Mearlmica CF, mica, manufactured by BASF, average value of long side and short side (A): 21 μm, refractive index: 1.58
B4: R-11, talc, manufactured by Matsumura Sangyo Co., Ltd., average value of long and short sides (A): 2.6 μm, refractive index: 1.57
Organic particles C1: Techpolymer SBX-17, styrene particles, manufactured by Sekisui Plastics Co., Ltd., number average particle size: 9.1 μm, refractive index: 1.59

<Measurement of average value (A) of long side and short side of layered clay mineral>
The average value of the long side and short side (A) was obtained by randomly extracting 100 layered clay minerals observed with a scanning electron microscope, and measuring the length of the surface forming the layer for each particle, that is, the surface with the maximum area. The average value (B) of the sides and short sides was measured, and the average value (A) was calculated from the average values (B) of 100 long sides and short sides. The long side is the side corresponding to the major axis when the maximum area of the particle is approximated by an ellipse, and the short side is the side corresponding to the minor axis when the maximum area of the particle is approximated by the ellipse.

<Measurement of refractive index of layered clay mineral>
The refractive indices of layered clay minerals and organic particles were measured according to JIS K7142 B method.
The refractometer used was “Abbe Refractometer 2T” manufactured by Atago Co., Ltd., and the microscope used was “Small Measuring Microscope STM5-311” manufactured by Olympus Co., Ltd.

2. Examples 1-3, Comparative Examples 1-5
<Production of pellets>
Each component described above was weighed so that the addition amount described in Table 1 was obtained. Each component in Table 1 is shown in parts by mass. Then, after mixing for 10 minutes in a tumbler, melt-kneading was performed at a cylinder temperature of 300° C. with a vented twin-screw extruder ("TEX30α" manufactured by Japan Steel Works, Ltd.) with a screw diameter of 32 mm, and pellets were obtained by strand cutting.

<Film production>
Using the obtained pellets, a film was produced by the following method.
Using a T-die melt extruder consisting of a twin-screw extruder with a barrel diameter of 32 mm and a vented screw L/D = 31.5 (manufactured by Japan Steel Works, Ltd., "TEX30α"), The melt was extruded under the conditions of a discharge rate of 10 kg/h and a screw rotation speed of 166 rpm, and cooled and solidified by a second roll to prepare a film. Cylinder temperature and die head temperature were 300°C.
The thickness of the film finally obtained was adjusted by changing the roll speed of the second roll so as to obtain the values shown in Table 1.

Details of the second roll used are as follows.
・Second roll: Made by JSW, metal rigid roll (surface: hard chrome treatment)
Core metal diameter: outer diameter 250 mm x width 600 mm
Roll temperature: 140°C

<Measurement of surface roughness Sa>
Sa defined in ISO25718-2:2012 was measured on the uneven surface of the obtained film using a scanning white light interference microscope. Measurements and analyzes were performed at three arbitrary locations, and the average value was adopted. The unit of Sa is nm.
The measurement conditions were as follows.
Field of view: CCD camera for single field measurement: 1/3 inch Objective lens: ×5
Observation area: 935.267×701.502 μm ²
Field of view size: 640 x 480 pixels
Measurement mode: wave mode Wavelength filter: 530 nm White
Observation conditions Interpolation conditions: Perfectly interpolated surface correction conditions: Fourth-order polynomial approximation As a scanning white light interference microscope, "VS1550" manufactured by Hitachi High-Tech Co., Ltd. was used.

<Measurement of total light transmittance and haze>
The total light transmittance (unit: %) and haze (unit: %) of the obtained film were measured under the condition of D65 light source and 10° field of view.
A haze meter (“HM-150” manufactured by Murakami Color Research Laboratory) was used for the measurement.

<Measurement of dynamic friction coefficient>
The dynamic friction coefficient of the film was measured as the dynamic friction coefficient against a film having a root-mean-square roughness of 0.093 μm.
A film having a root-mean-square roughness of 0.093 μm and the film obtained above are placed so that they overlap each other, and under the conditions of a thread of 100 mm / min and a load cell of 10 N, the film having a root-mean-square roughness of 0.093 μm , and the resulting film was slid to measure the dynamic friction coefficient.
The friction coefficient measuring machine used was manufactured by Toyo Seiki Seisakusho Co., Ltd. (“Friction Tester”).
A film having a root-mean-square roughness of 0.093 μm was a bisphenol A polycarbonate resin film with a masking film on one side (FE-2000, thickness 100 μm, manufactured by Mitsubishi Gas Chemical Company, Inc.). In this example, the bisphenol A polycarbonate resin film with a single-sided masking film was fixed to the right end of the test table with a tape so that the masked side of the film was peeled off and the long axis coincided with the long axis of the test table, and the thickness was 63 mm. The resulting film was attached to the underside of a 63 mm, 200 g thread, placed so that the polycarbonate resin film and the resulting film overlapped, and the resulting film was slid as described above to measure the dynamic friction coefficient. bottom.
In Comparative Examples 3 to 5, suitable irregularities could not be formed on the surface, the films stuck to each other, and the dynamic friction coefficient could not be measured.

<Measurement of root mean square roughness Rq>
The surface roughness of the film having a root-mean-square roughness of 0.093 μm used for the measurement of the dynamic friction coefficient was measured using a surface roughness measuring machine.
The detector of the measuring machine was made "integrated type", and the driving part of the detector was equipped with a "standard drive unit". The film was fixed on a glass plate with tape, and the surface roughness measuring machine was placed on the film so as not to move. After that, the measurement conditions were standard "JIS B 0601-2001", the measurement speed was 0.5 mm/s, the cutoff value was 0.8, and the number of sections was 3, and the root mean square roughness Rq was measured. The root-mean-square roughness Rq was measured three times at different locations on the film and taken as the average value.
As a measuring machine, "SJ-210" manufactured by Mitutoyo Corporation was used.

<Evaluation of rolled appearance>
In the production of the film, the second roll speed is adjusted so that the film has a predetermined thickness, and the take-up tension of the film winder is controlled to 200 N, and a masking film is used. First, the appearance of the film was evaluated when the film was wound on a paper tube having an inner diameter of 3 inches for 30 m. Five experts evaluated and made a majority decision.
A: Winding was possible with good appearance without wrinkles.
B: Other than the above A and C, for example, winding was possible, but stacking occurred, winding wrinkles occurred, and the like.
C: Could not be wound along the paper tube.

<Evaluation of projection>
A projected image of the obtained film was obtained by irradiating with a high-intensity light source.
Specifically, a white paper is pasted on the wall, a high-intensity light source is installed at a position 120 cm away from the white paper, and a film placed between the wall and the light source, that is, at a position 60 cm from the wall is irradiated. A projection image of the film was obtained on a white paper attached to the wall.
"S-Light" manufactured by Nippon Gijutsu Center Co., Ltd. was used as a high-intensity light source.
A: The image can be clearly seen.
B: The image is blurred.

<Coating of adhesive>
The films obtained in Examples 1 to 3 were each subjected to adhesive coating by the following method to produce an adhesive sheet.
The film obtained by the above method is coated with a silicone pressure-sensitive adhesive described later using a bar coater so that the thickness of the dry coating film becomes 30 μm, and a hot air circulation dryer (manufactured by Yamato Scientific Co., Ltd., "DNF611") is applied. and dried at 130° C. for 1 minute to form an adhesive layer. The adhesive layer was laminated to the side of the film that would contact the second roll. It was confirmed that it functions properly as a film with an adhesive layer.

The composition of the adhesive used is as follows.
Silicone adhesive: X-40-3229, manufactured by Shin-Etsu Chemical Co., Ltd., 100 parts by mass Catalyst: CAT-PL-50T, manufactured by Shin-Etsu Chemical Co., Ltd., 0.5 parts by mass Diluting solvent: Toluene, 50 parts by mass

<Evaluation of bubble generation after heating>
The resulting pressure-sensitive adhesive sheet was laminated to a bisphenol A polycarbonate resin film (manufactured by Mitsubishi Gas Chemical Co., Ltd., FE-2000, thickness 100 μm) having a root-mean-square roughness of 0.093 μm. DKN402) at 140° C. for 1 hour. After heating, the appearance of the film was evaluated. Five experts evaluated and made a majority decision.
A: No air bubbles were generated. B: Air bubbles were observed in a portion of the film. C: Air bubbles were generated on the entire surface.

1: Film 2: Adhesive layer

Claims (10)

A film containing 0.005 to 0.5 parts by mass of a layered clay mineral with respect to 100 parts by mass of a polycarbonate resin,
The film has a surface roughness Sa of 10 to 100 nm,
A film having a thickness of 50 to 200 μm. 2. The film according to claim 1, wherein the layered clay mineral has an average long side and short side of 2.0 μm to 9.0 μm. 3. The film according to claim 1, wherein the layered clay mineral has a refractive index of 1.55 to 1.63. 3. The film of claim 1 or 2 , wherein the layered clay mineral comprises mica. 3. The film of claim 1 or 2 , wherein the film has a haze of 2% or less under D65 illuminant 10[deg.] field of view conditions. 3. The film according to claim 1, which is a substrate for a protective film. The average value of the long side and the short side of the layered clay mineral is 2.0 μm to 9.0 μm,
The layered clay mineral has a refractive index of 1.55 to 1.63,
The layered clay mineral contains mica,
The film has a haze of 2% or less in a D65 light source 10° field of view,
The film according to claim 1, which is a substrate for a protective film. 8. A multilayer film comprising the film of claim 1 , 2 or 7 and other layers. 9. A multilayer film according to claim 8 , wherein said other layer comprises an adhesive layer. a protective layer;
an adhesive layer;
a substrate;
A transparent conductive film having an electrode layer in this order,
A transparent conductive film, wherein the protective layer is the film according to claim 1 , 2 or 7 .

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