CN114507432A

CN114507432A - Film, multilayer body, and transparent conductive film

Info

Publication number: CN114507432A
Application number: CN202111352997.3A
Authority: CN
Inventors: 石井太树; 小坂惠梦
Original assignee: Mitsubishi Gas Chemical Co Inc; MGC Filsheet Co Ltd
Current assignee: Mitsubishi Gas Chemical Co Inc; MGC Filsheet Co Ltd
Priority date: 2020-11-17
Filing date: 2021-11-16
Publication date: 2022-05-17
Also published as: JP2022080271A

Abstract

The invention provides a film, a multilayer body and a transparent conductive film, wherein the film has a small rate of change of retardation before and after heat forming, excellent bending resistance and excellent transparency. The film contains an aromatic polycarbonate resin having a terminal structure represented by the formula (1), an aromatic resinThe polycarbonate resin has a viscosity average molecular weight of 17000 to 40000, a film thickness of 20 to 150 μm, and a surface roughness Ra of less than 0.7 μm. In the formula (1), R¹Represents an alkyl group having 8 to 36 carbon atoms or an alkenyl group having 8 to 30 carbon atoms.

Description

Film, multilayer body, and transparent conductive film

Technical Field

The invention relates to a film, a multilayer body, and a transparent conductive film.

Background

Transparent conductive films are used in film sensors for touch panels, electronic paper, dye-sensitized solar cells, touch sensors, and the like. As shown in fig. 1, for example, a transparent conductive film 10 is known to be composed of an electrode layer (transparent conductive film) 11, a substrate 12, an adhesive layer 13, and a protective film 14. As a specific example of such a transparent conductive film, for example, a film described in patent document 1 is known. A film mainly composed of a polycarbonate resin may be used as the base material and the protective film of such a transparent conductive film. Further, as films mainly composed of a polycarbonate resin, films described in patent documents 2 and 3 have been studied.

Documents of the prior art

Patent document

Patent document 1: japanese patent laid-open publication No. 2018-152187

Patent document 2: international publication No. 2016/060100

Patent document 3: japanese patent laid-open publication No. 2019-002023

Disclosure of Invention

Technical problem to be solved by the invention

Among them, when a film mainly composed of a polycarbonate resin is used for a transparent conductive film, a small change rate of retardation before and after heat forming and bending resistance are required depending on the use. That is, when the film is a curved display panel, large retardation change during heat-shaping causes rainbow unevenness (coloring due to birefringence). Further, when the bending resistance is poor, it may be difficult to use the display panel in a curved surface, a folded display panel, or the like. In addition, since it is a display screen, it is needless to say that a transparent film is required. Such performance is also required when a film mainly composed of a polycarbonate resin is used for a shatter prevention film of curved glass or the like.

The present invention is directed to solve the above-mentioned problems, and relates to a film having a small change rate of retardation before and after heat forming, excellent bending resistance, and excellent transparency, and a multilayer body and a transparent conductive film comprising the film.

Technical solution for solving technical problem

The present inventors have conducted studies based on the above-mentioned problems, and as a result, have found that the above-mentioned problems can be solved by using an aromatic polycarbonate resin having a predetermined molecular weight and a predetermined terminal structure and adjusting the thickness and surface roughness of the film to predetermined ranges.

The above technical problem can be solved by the following means.

< 1 > a film comprising an aromatic polycarbonate resin having a terminal structure represented by the formula (1), wherein the aromatic polycarbonate resin has a viscosity average molecular weight of 17000 to 40000, the film has a thickness of 20 to 150 μm, and the film has a surface roughness Ra of less than 0.7 μm.

(in the formula (1), R¹Represents an alkyl group having 8 to 36 carbon atoms or an alkenyl group having 8 to 30 carbon atoms, R²Each independently represents a halogen atom, an alkyl group having 1 to 20 carbon atoms or an aryl group having 6 to 12 carbon atoms, n represents an integer of 0 to 4, and represents a bonding site with another site. )

< 2 > such as < 1 > wherein the glass transition temperature of the film is 115 to 142 ℃.

A film of < 3 > such as < 1 > or < 2 > wherein the aromatic polycarbonate resin has a viscosity average molecular weight of 30000 to 40000.

< 4 > such as < 1 > or < 2 >, wherein the aromatic polycarbonate resin has a viscosity average molecular weight of 17000 or more and less than 30000.

[ 5 ] the film according to any one of [ 1 ] to [ 4 ], wherein the film has a surface roughness Ra of 0.1 μm or less.

The film of < 6 > such as < 1 > -to < 5 >, wherein the film has a haze of 10% or less.

< 7 > the film according to any one of < 1 > - < 6 >, wherein the retardation (Re) of the film with respect to light having a wavelength of 543nm is 25nm or less.

The film of any one of < 8 > such as < 1 > to < 7 > which is a single layer film.

< 9 > a multilayer body having the film of any one of < 1 > -to < 8 > and at least 1 further layer.

< 10 > A multilayer body as < 9 > wherein the other layers comprise an adhesive layer.

< 11 > A transparent conductive film comprising 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 is any one of < 1 > - < 8 >.

Effects of the invention

According to the present invention, a film having a small change rate of retardation before and after heat forming, excellent bending resistance, and excellent transparency, and a multilayer body and a transparent conductive film each including the film can be provided.

Drawings

Fig. 1 is a schematic cross-sectional view showing an example of a layer structure of a transparent conductive film.

Fig. 2 is a diagram showing a mold for measuring a delay increase rate before and after thermal forming in the example.

FIG. 3 is a view showing a method of applying strain for measuring chemical resistance of examples.

Description of the symbols

10: a transparent conductive film; 11: an electrode layer (transparent conductive film); 12: a substrate; 13: an adhesive layer; 14: a protective film; 21: an upper die; 22: a lower die; 31: and (3) testing the test piece.

Detailed Description

Hereinafter, specific embodiments of the present invention (hereinafter, simply referred to as "the present embodiment") will be described in detail. However, the present embodiment is an example for explaining the present invention, and the present invention is not limited to the present embodiment.

In the present specification, the term "to" is intended to include the numerical values described before and after the term as the lower limit value and the upper limit value.

In the present specification, unless otherwise specified, various physical property values and characteristic values refer to values at 23 ℃.

In labeling of a group (atomic group) in the present specification, the case where substitution and non-substitution are not labeled includes the case of a group (atomic group) having no substituent and the case of a group (atomic group) having a substituent. For example, "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 the present specification, in the case where there is no label substitution and no substitution, no substitution is preferred.

The multilayer body in the present specification includes a case of forming a shape of a film or a sheet. "film" and "sheet" refer to generally flat shaped bodies having a thin thickness relative to the length and width, respectively. In addition, the "film" in the present specification may be a single layer or a multilayer.

In the present specification, "part by mass" means a relative amount of a component, and "mass%" means an absolute amount of the component.

The film of the present embodiment is characterized in that: the film comprises an aromatic polycarbonate resin having a terminal structure represented by the formula (1), wherein the aromatic polycarbonate resin has a viscosity average molecular weight of 17000 to 40000, the film has a thickness of 20 to 150 [ mu ] m, and the film has a surface roughness Ra of less than 0.7 [ mu ] m.

(in the formula (1), R¹Represents an alkyl group having 8 to 36 carbon atoms or an alkenyl group having 8 to 30 carbon atoms. R²Each independently represents a halogen atom, an alkyl group having 1 to 20 carbon atoms, or an aryl group having 6 to 12 carbon atoms. n represents an integer of 0 to 4. The bonding site to other sites. )

With the above configuration, a film having a small change rate of retardation before and after heat forming, excellent bending resistance, and excellent transparency can be obtained. Further, a film having excellent chemical resistance can be obtained. When the chemical resistance is excellent, the occurrence of cracks due to a solvent can be effectively suppressed when a pressure-sensitive adhesive layer, a hard coat layer, or the like is applied.

That is, it is estimated that the increase of retardation (Re) at the time of thermal forming can be suppressed because the glass transition temperature of the aromatic polycarbonate resin is lowered by making the terminal of the aromatic polycarbonate resin have the structure represented by formula (1), and the heat resistance of the film is reduced by making the thickness of the film thin, and the film is formed in a softened state. If the increase of Re during thermal shaping is suppressed, birefringence is reduced, and rainbow unevenness (coloring due to birefringence) of the display screen can be effectively suppressed. Further, it is presumed that the molecular weight of the aromatic polycarbonate resin is in a predetermined range and the thickness of the film is reduced, whereby the film can be made resistant to bending and excellent in bending resistance can be obtained. Further, it is presumed that a film having excellent transparency can be obtained by using an aromatic polycarbonate resin and reducing the surface roughness of the film. Further, it is presumed that a film having excellent chemical resistance can be obtained by adjusting the molecular weight of the aromatic polycarbonate resin to a predetermined range.

The following describes the details of the present embodiment.

The film of the present embodiment contains an aromatic polycarbonate resin having a terminal structure represented by formula (1). By using such an aromatic polycarbonate resin, the glass transition temperature of the aromatic polycarbonate resin is lowered, and the increase of the retardation (Re) during heat forming can be suppressed.

R¹Represents an alkyl group having 8 to 36 carbon atoms or an alkenyl group having 8 to 30 carbon atoms, preferably an alkyl group or alkenyl group having 12 or more carbon atoms, and more preferably an alkyl group or alkenyl group having 14 or more carbon atoms. In addition, R¹Preferably an alkyl group or alkenyl group having 22 or less carbon atoms, and more preferably an alkyl group or alkenyl group having 18 or less carbon atoms. R is¹Preferably an alkyl group. The alkyl group and the alkenyl group are preferably linear or branched, and more preferably linear.

In the present embodiment, R¹Cetyl is particularly preferred.

In addition, R¹Can be in any position of meta, para, ortho, preferably in meta or para, more preferably in para.

R²Each independently represents a halogen atom, an alkyl group having 1 to 20 carbon atoms or an aryl group having 6 to 12 carbon atoms, preferably a fluorine atom, a chlorine atom, a methyl group, an ethyl group or a phenyl group, more preferably a fluorine atom, a chlorine atom or a methyl group.

n represents an integer of 0 to 4, preferably an integer of 0 to 2, more preferably 0 or 1, and still more preferably 0.

The terminal structure represented by the formula (1) can be added to polycarbonate by using an end-capping agent such as cetyl p-hydroxybenzoate. The details of these can be referred to the descriptions in paragraphs 0022 to 0030 of Japanese patent application laid-open Nos. 2019 and 002023, and these contents are incorporated into the present specification.

In the aromatic polycarbonate resin having a terminal structure represented by formula (1) used in the present embodiment, the number of terminal structures represented by formula (1) may be 1, or 2 or more.

In the present embodiment, the aromatic polycarbonate resin having a terminal structure represented by formula (1) is preferably a bisphenol type polycarbonate resin, and more preferably a bisphenol a type polycarbonate resin.

The bisphenol a polycarbonate resin may have a structural unit other than a carbonate structural unit derived from bisphenol a and a derivative thereof. Examples of the dihydroxy compound constituting such another structural unit include aromatic dihydroxy compounds described in paragraph 0014 of Japanese patent laid-open publication No. 2018-154819, which are incorporated herein by reference.

In the bisphenol polycarbonate resin in the present embodiment, the carbonate structural unit derived from bisphenol a and its derivative is preferably 90 mass% or more, more preferably 95 mass% or more, and still more preferably 97 mass% or more of the total structural units excluding the terminal structure.

The method for producing the bisphenol a polycarbonate resin is not particularly limited, and any method may be employed. Examples thereof include interfacial polymerization, melt transesterification, pyridine method, ring-opening polymerization of cyclic carbonate compounds, and solid-phase transesterification of prepolymers.

The aromatic polycarbonate resin used in the present embodiment has a viscosity average molecular weight of 17000 to 40000. When the viscosity average molecular weight is 17,000 or more, the film can be made resistant to bending and can have excellent bending resistance. Further, when the viscosity average molecular weight is 40000 or less, the glass transition temperature of the film tends to be effectively lowered, and the increase in Re during heat shaping can be effectively suppressed.

The viscosity average molecular weight of the aromatic polycarbonate resin is preferably 20000 or more, more preferably 22000 or more, further preferably 24000 or more, further 30000 or more. In particular, by setting 30000 or more, the bending resistance tends to be further improved. The viscosity average molecular weight of the aromatic polycarbonate resin is preferably 38000 or less, more preferably 35000 or less, particularly preferably less than 30000, and still more preferably 28000 or less. In particular, when the viscosity average molecular weight is less than 30000 and further 28000 or less, the viscosity of the aromatic polycarbonate resin tends to be reduced and the filter permeability tends to be improved. When the permeability of the filter is improved, foreign matter in the membrane can be reduced.

When the film of the present embodiment contains the aromatic polycarbonate resin having a terminal structure represented by formula (1) and another aromatic polycarbonate resin, the viscosity-average molecular weight of the polycarbonate resin as a blend thereof preferably satisfies the above range.

The Q value of the aromatic polycarbonate resin used in the present embodiment is preferably 30X 10^-2cc/sec or less, more preferably 20X 10^-2cc/sec or less, more preferably 10X 10^-2cc/sec or less, more preferably 8X 10^-2cc/sec or less, more preferably 4.0X 10^-2cc/sec or less. Tong (Chinese character of 'tong')If the upper limit is not more than the above-mentioned upper limit, the film tends to have improved bending resistance and chemical resistance. The lower limit of the Q value is preferably 0.1X 10^-2cc/sec or more, more preferably 0.5X 10^-2cc/sec or more, and more preferably 1.0X 10^-2cc/sec or more, more preferably 3.0X 10^- ²cc/sec or more, and may be 5.0X 10^-2cc/sec or more. When the lower limit value is not less than the above-mentioned lower limit value, the fluidity tends to be high, and the filter permeability tends to be high. When the permeability of the filter is improved, foreign matter in the membrane can be reduced.

When the film of the present embodiment contains the aromatic polycarbonate resin having a terminal structure represented by formula (1) and another aromatic polycarbonate resin, the Q value of the polycarbonate resin as a blend thereof preferably satisfies the above range.

The glass transition temperature of the aromatic polycarbonate resin having a terminal structure represented by formula (1) used in the present embodiment is preferably 145 ℃ or lower, more preferably 142 ℃ or lower, still more preferably 140 ℃ or lower, yet more preferably 135 ℃ or lower, and yet more preferably 132 ℃ or lower. When the value is equal to or less than the upper limit, the Re increase during heat forming tends to be more effectively suppressed. The aromatic polycarbonate resin having a terminal structure represented by formula (1) used in the present embodiment preferably has a glass transition temperature of 115 ℃ or higher, more preferably 120 ℃ or higher, and still more preferably 123 ℃ or higher. When the lower limit value is not less than the above-described lower limit value, the bending resistance tends to be further improved. When the film of the present embodiment contains the aromatic polycarbonate resin having a terminal structure represented by formula (1) and another aromatic polycarbonate resin, the glass transition temperature of the polycarbonate resin as a blend thereof preferably satisfies the above range.

The proportion of the aromatic polycarbonate resin (preferably, the aromatic polycarbonate resin having a terminal structure represented by formula (1)) in the film of the present embodiment is preferably 90% by mass or more, more preferably 95% by mass or more, and still more preferably 97% by mass or more of the film. When the lower limit value is not less than the above-mentioned lower limit value, a film having more excellent transparency can be obtained. The upper limit of the proportion of the aromatic polycarbonate resin in the film of the above embodiment may be 100% by mass.

The film of the present embodiment may contain only 1 kind of aromatic polycarbonate resin, or may contain 2 or more kinds. When 2 or more species are contained, the total amount is preferably in the above range.

< other ingredients >

The film of the present embodiment may contain other components in addition to the aromatic polycarbonate resin having a terminal structure represented by formula (1) within a range not departing from the gist of the present invention. Specifically, polycarbonate resins other than the aromatic polycarbonate resins, thermoplastic resins other than the polycarbonate resins, antioxidants, transesterification inhibitors, mold release agents, heat stabilizers, flame retardants, flame retardant aids, ultraviolet absorbers, colorants, antistatic agents, fluorescent whitening agents, antifogging agents, flow improvers, plasticizers, dispersants, antibacterial agents, antiblocking agents, impact improvers, slip improvers, hue improvers, acid trapping agents, and the like can be contained. These components may be used in 1 kind, or 2 or more kinds may be used in combination. The details of these can be referred to the descriptions of Japanese patent laid-open Nos. 2017-031313, 2015/190162, 2019-002023 and 2018-199745, and these contents are incorporated into the present specification.

< physical Properties and Properties of film >

The thickness of the film of the present embodiment is 20 to 150 μm. By setting the thickness to 20 μm or more, the film can be inhibited from breaking, and a film having excellent strength can be obtained. Further, by setting the thickness to 150 μm or less, the increase of Re during heat shaping can be suppressed, and the bending resistance can be improved. The thickness of the film is preferably 25 μm or more, and more preferably 30 μm or more. The thickness of the film is preferably 140 μm or less, more preferably 100 μm or less, still more preferably 70 μm or less, and still more preferably 60 μm or less.

The surface roughness Ra of the film of the present embodiment is less than 0.7 μm. With such a configuration, a film having excellent transparency can be obtained. The surface roughness is preferably 0.5 μm or less, more preferably 0.1 μm or less, still more preferably 0.08 μm or less, yet more preferably 0.05 μm or less, and yet more preferably 0.02 μm or less. The lower limit value of the surface roughness Ra of the film is preferably 0 μm, but it is actually 0.0001 μm or more, and further, the required performance can be sufficiently satisfied even when the lower limit value is 0.001 μm or more.

The glass transition temperature of the film of the present embodiment is preferably 115 to 142 ℃. When the lower limit value is not less than the above-described lower limit value, the bending resistance tends to be further improved. Further, by setting the upper limit value or less, the increase of Re during heat forming tends to be more effectively suppressed. The glass transition temperature of the film is preferably 140 ℃ or lower, more preferably 135 ℃ or lower, and still more preferably 132 ℃ or lower. The glass transition temperature of the film is preferably 115 ℃ or higher, more preferably 120 ℃ or higher, and still more preferably 123 ℃ or higher.

The retardation (Re) of the film of the present embodiment with respect to light having a wavelength of 543nm is preferably 25nm or less, more preferably 15nm or less, further preferably 10nm or less, further preferably 8nm or less, further preferably 5nm or less, and further preferably 3nm or less. When the upper limit value is equal to or less than the upper limit value, the rainbow unevenness tends to be more effectively suppressed. The lower limit of the retardation (Re) is preferably 0nm, but it is actually 0.01nm or more.

The haze of the film of the present embodiment is preferably 10% or less, more preferably 5% or less, further preferably 1% or less, further preferably 0.5% or less, and further preferably 0.2% or less. When the upper limit value is not more than the above-mentioned upper limit value, the transparency of the film tends to be further improved. The lower limit value of the haze of the film is preferably 0%, but it is realistic that the lower limit value is 0.001% or more.

The Ra, glass transition temperature, Re, and haze can be measured based on the descriptions of examples described below.

< method for producing film >

The film of the present embodiment can be produced by a known method, and for example, extrusion molding and cast molding are preferable. Examples of extrusion molding include the following methods: pellets, sheets or powder of the resin composition to which the aromatic polycarbonate resin and, if necessary, additives are added are melted and kneaded by an extruder, and then extruded from a T die or the like, and the obtained sheet in a semi-molten state is cooled and solidified while being nipped by a polishing roll or the like, to obtain a product. The extruder may be a single screw or a twin screw, and may be used with or without vents.

When the film of the present embodiment is a multilayer body, it can be produced by a known method. For example, when melt extrusion is performed using a T die, a multilayer film can be formed by laminating the layers inside a die to form a film shape, or laminating the layers after forming the film shape.

< use >)

The film of the present embodiment may be used in the form of a single-layer film. As described above, the film of the present embodiment may be used as a multilayer body including the film of the present embodiment and at least 1 other layer. As the other layer, a known layer can be used, and an adhesive layer or a hard coat layer can be exemplified, and an adhesive layer is preferably included. Of course, both an adhesive layer and a hard coat layer may be provided.

As the adhesive layer, a polyolefin resin layer can be exemplified.

The hard coat layer can be described in paragraphs 0045 to 0055 in Japanese patent application laid-open No. 2013-020130, paragraphs 0073 to 0076 in Japanese patent application laid-open No. 2018-103518, and paragraphs 0062 to 0082 in Japanese patent application laid-open No. 2017-213771, which are incorporated herein by reference.

The film of the present embodiment is preferably used as a protective film or a base material for a transparent conductive film. In particular, it is preferably used as a transparent conductive film having a protective layer, an adhesive layer, a base material, and an electrode layer in this order, and at least one of the base material and the protective layer (preferably at least the protective layer) is the film of the present embodiment.

The transparent conductive film is preferably used as a transparent conductive film used for a film sensor of a touch panel, an electronic paper, a dye-sensitized solar cell, a touch sensor, and the like.

Further, in addition to the above, the film of the present embodiment is preferably used for applications requiring a small change rate of retardation before and after heat forming, excellent bending resistance, and high transparency. For example, it can be used as an anti-scattering film.

[ examples ] A

The present invention will be described more specifically with reference to examples. The materials, the amounts used, the proportions, the contents of the treatments, the treatment steps and the like shown in the following examples may be appropriately changed without departing from the gist of the present invention. Therefore, the scope of the present invention is not limited to the specific examples shown below.

When the measurement device used in the examples is not easily available due to, for example, abolishment of model, the measurement can be performed using other devices having equivalent performance.

1. Raw materials

< preparation example of PC-1 >

The esterification reaction was carried out by dehydration reaction using 4-hydroxybenzoic acid produced by Tokyo chemical industry Co., Ltd and 1-hexadecanol produced by Tokyo chemical industry Co., Ltd based on the description of organic chemistry handbook P143 to 150 to obtain hexadecyl P-hydroxybenzoate (CEPB).

7.1kg (31.14mol) of bisphenol A (BPA) produced by Nippon iron Japan chemical Co., Ltd and 30g of sodium dithionite were added to and dissolved in 57.2kg of a 9 mass% aqueous solution of sodium hydroxide. 40kg of methylene chloride was added thereto, and 4.33kg of phosgene was blown in 30 minutes while keeping the solution temperature in the range of 15 to 25 ℃ with stirring.

After the phosgene blowing was completed, 6kg of a 9 mass% aqueous solution of sodium hydroxide, 11kg of methylene chloride and a solution obtained by dissolving 443g (1.22mol) of CEPB obtained above in 10kg of methylene chloride were added, and the mixture was emulsified by vigorous stirring, and then 10mL of triethylamine as a polymerization catalyst was added to conduct polymerization for about 40 minutes.

The polymerization solution is separated into a water phase and an organic phase, the organic phase is neutralized by phosphoric acid, and the organic phase is repeatedly washed by pure water until the pH of the washing solution is neutral. The organic solvent was evaporated from the purified aromatic polycarbonate resin solution to obtain an aromatic polycarbonate resin powder (PC-1).

To 100 parts by mass of the obtained aromatic polycarbonate resin powder, 0.0075 parts by mass of ADEKA STAB 2112 (available from ADEKA corporation, tris (2, 4-di-t-butylphenyl) phosphite) as an antioxidant and 0.0045 parts by mass of RIKEMAL S-100A (RIKEN VITAMIN co., ltd., glycerin monostearate) as a release agent were added, and after 15 minutes of mixing by a tumbler, melt-kneading was performed at a cylinder temperature of 280 ℃ by a twin-screw extruder with a vent having a screw diameter of 32mm ("TEX 30 α" available from japan steel corporation), and pellets were obtained by a strand cutter. The viscosity average molecular weight (Mv) and glass transition temperature (Tg) of the obtained aromatic polycarbonate resin pellets were measured.

< production example of PC-2 >

In the production example of < PC-1 > above, CEPB was 348g (0.96mol), and the same procedure was repeated.

< production example of PC-3 >

In the production example of < PC-1 > above, the same procedure was repeated except that CEPB was 266g (0.73 mol).

< production example of PC-4 >

In the production example of < PC-1 > above, CEPB was 940g (2.59mol), and the same was conducted except that the amount was changed.

< production example of PC-5 >

In the production example of < PC-1 > described above, the aromatic polycarbonate resin powder used in the production of the pellets was a mixture of a bisphenol A type polycarbonate resin having a p-tert-butylphenyl terminal structure (manufactured by Mitsubishi engineering plastics corporation, E-2000F, viscosity average molecular weight: 28000, Tg: 150 ℃) and a bisphenol A type polycarbonate resin having a p-tert-butylphenyl terminal structure (manufactured by Mitsubishi engineering plastics corporation, S-3000F, viscosity average molecular weight: 21000, Tg: 146 ℃) in a mass ratio of 1 to 1, and the other procedures were carried out in the same manner.

< filterability of filter >

When the pellets were produced, a polymer filter having a mesh size of 20 μm was attached to a vented twin-screw extruder, and the case where the pressure during extrusion exceeded the upper limit and extrusion was impossible was designated as B, and the case where extrusion was possible was designated as A.

< determination of viscosity average molecular weight (Mv) >

The viscosity average molecular weight of the aromatic polycarbonate resin was measured by the following method.

The intrinsic viscosity [ eta ] at 25 ℃ was determined using methylene chloride as a solvent and an Ubbelohde viscometer](unit dL/g), viscosity formula according to Schnell, i.e. η ═ 1.23X 10^-4Mv^0.83And (6) calculating. In addition, the intrinsic viscosity [ eta ]]Is to measure the concentration [ C ] of each solution]Specific viscosity at (g/dL) [. eta. ]_sp]And a value calculated by the following formula.

< Q value >

The obtained pellets were dried with a hot air circulation dryer at 110 ℃ for 5 hours using a high-pressure flow tester, and then subjected to a load: 160kgf/cm²And a hole: the Q value of the aromatic polycarbonate resin was measured at 280 ℃ with a diameter of 1 mm. times.a length of 10 mm. The unit of Q value is expressed in 0.01 cc/sec.

The advanced flow tester used CFT-500D manufactured by Shimadzu corporation.

< measurement of glass transition temperature (Tg) >

The glass transition temperatures of the film and the aromatic polycarbonate resin pellets were measured as follows.

About 10mg of the film or the aromatic polycarbonate resin pellet was subjected to two cycles of temperature increase and temperature decrease under the following measurement conditions of DSC (differential scanning calorimeter), and the glass transition temperature at the time of temperature increase in the second cycle was measured. The glass transition temperature (Tg, unit:. degree. C.) was determined as the glass transition starting temperature at the intersection of the line extending from the base line on the low temperature side to the high temperature side and the tangent to the inflection point, the intersection of the line extending from the base line on the high temperature side to the low temperature side and the tangent to the inflection point, and the midpoint between the glass transition starting temperature and the glass transition ending temperature.

Measurement start temperature: 30 deg.C

Temperature rise rate: 10 ℃/min

The arrival temperature: 250 deg.C

Cooling speed: 20 ℃ per minute

The measurement apparatus used was a differential scanning calorimeter (DSC, manufactured by Hitachi Kagaku K.K., "DSC 7020").

2. Examples 1 to 5 and comparative examples 1 to 4

< production of film >

Using the pellets obtained above, a film was produced in the following manner.

The obtained pellets were extruded in a molten state under conditions of a discharge rate of 10kg/h and a screw rotation speed of 150rpm using a T-die melt extruder (manufactured by japan steel-making corporation, "TEX 30 α") equipped with a double-screw extruder having a barrel diameter of 32mm and a screw with a vent, L/D of 31.5, and then pressure-bonded using a first roll and a second roll, followed by cooling and solidification to prepare a film. The barrel and T-die temperatures were 280 ℃.

The thickness (unit: μm) of the finally obtained film was adjusted to the values shown in table 1 or table 2 by changing the roll speed of the first roll and the second roll.

Details of the first roller and the second roller used are as follows.

First roller: silicone rubber roll (IT68S-MCG) size, manufactured by Tayota Doku Kogyo Co., Ltd.: outer diameter 260mm x width 600mm

Roll temperature: 50 deg.C

A second roller: mirror metal rigid body roller (surface: hard chromium treatment)

The size of the core die is as follows: outer diameter 250mm x width 600mm

Roll temperature: 120 deg.C

The obtained film was evaluated as follows.

Among them, comparative example 2 was broken at the time of producing the film, and thus in table 2, no evaluation was made with respect to the item indicated as "-".

< surface roughness (Ra) >)

The film obtained above was measured for arithmetic average surface roughness Ra using a contact surface roughness meter. Specifically, the evaluation is based on JIS B0601: 2001, 3 points in the width direction of the surface of the film in contact with the second roller were measured, and the average value thereof was calculated. The units are expressed in μm.

The measuring apparatus used was "SURFTEST SJ-210" manufactured by Mitutoyo Corporation.

< delay (Re) >

The film obtained above was cut out to a size of 50X 150mm, and the retardation was measured at a wavelength of 543 nm. The units are expressed in nm.

The delay was measured using WPA-100 manufactured by Photonic latex Inc.

< delay Up (Δ Re) > < before and after thermal Forming

The film obtained above was cut out to a size of 50X 150mm, and the retardation was measured at a wavelength of 543 nm. As for the measurement results, a line analysis was performed on a length of 100mm in the longitudinal direction from a position 25mm from the short-side end of the film and 25mm from the long-side end of the film, and the maximum value thereof was taken as the maximum value of the retardation before the heat-forming. The upper die 21 and the lower die 22 shown in fig. 2 are mounted on the hydraulic jack press. The mold was heated to 130 ℃, the film after the retardation measurement was placed on the mold, and the film was held for 1 minute with a gap of 1mm between the upper and lower molds, and heat-shaped under a pressure of 0.5MPa and a pressing time of 1 minute. The film was taken out, cooled to 23 ℃ and measured for retardation in the same manner as before thermal forming to determine the maximum value of retardation after thermal forming, and the rate of increase in retardation (unit:%) before and after thermal forming was calculated by the following equation.

Delay increase rate ═ [ (maximum value of delay after thermal forming-maximum value of delay before thermal forming)/maximum value of delay before thermal forming ] × 100

The delay was measured using WPA-100 manufactured by Photonic latex Inc.

The calculated delay rise rate was evaluated and determined according to the following criteria.

A: less than 50 percent;

b: more than 50% and 120% or less;

c: over 120%.

< chemical resistance >

The obtained pellets were dried at 110 ℃ for 5 hours by a hot air circulation dryer. Thereafter, a 3mm ISO multi-mesh test piece was formed by an injection molding machine under conditions of a cylinder temperature of 280 ℃, a mold temperature of 80 ℃ and a molding cycle of 45 seconds (thickness of JIS-K7139A 1 type was changed from 4mm to 3 mm).

As the injection molding machine, "PE-100" (trade name) manufactured by Sodick corporation was used. The obtained test piece was annealed in an oven at 110 ℃ for 2 hours. As shown in fig. 3, the annealed test piece was coated with 2, 2-bis (4-glycidyloxyphenyl) propane as a test substance while applying a strain of 0.45%, held at 75 ℃ for 3 hours in an oven, and then cooled to 23 ℃. In fig. 3, 31 denotes a test piece, and L denotes an inter-fulcrum distance.

The strain [ epsilon ] (%) was calculated from the following equation using the bending [ s ] (mm) of the test piece, the thickness [ h ] (mm) of the test piece, and the distance [ L ] (mm) between the supporting points.

ε＝600sh/L²

Using I as shown in FIG. 3₀(mm) and I (mm), the bending [ s ] of the test piece was calculated by the following formula](mm)。

s＝I₀-I

The test samples were evaluated and judged by visual observation according to the following criteria. 5 experts evaluate and judge in a majority voting manner.

A: the coated surface was damaged by the chemicals, but the test piece was not broken.

B: the test piece was broken.

< flexibility resistance >

The film obtained above was cut into a size of 75 × 25mm, based on JIS C5016: 1994, bending resistance test of bending surface with a curvature radius of 4.0mm was carried out using FPC (Flexible printed Circuit) bending tester. In the bending resistance test of this time, the test specimens after the completion of the 2000-time bending test were evaluated and judged by visual observation according to the following criteria. 5 experts evaluate and vote for majority.

As the FPC bending tester, a No.306FPC bending tester (trade name) manufactured by Antaho Seiko K.K. was used.

S: neither deformation nor cracking of the film occurred.

A: the film was slightly deformed into a circular arc shape, but no cracks were generated.

B: the film was deformed into a circular arc shape, but no cracks were generated.

C: in addition to the above-mentioned a and B, for example, the film is deformed into an arc shape, and cracks or the like are generated.

< haze >

The film obtained above was measured for haze (unit:%) by a haze meter under the conditions of a D65 light source and a 10 ° field of view.

The haze meter used was HM-150 manufactured by Nikkiso color technology research institute, Inc.

Comparative example 5

The following modifications were made in the production of the film, and the other steps were performed in the same manner as in example 1.

A second roller: embossing roller with arithmetic average roughness of 2.4 mu m

The size of the core die is as follows: outer diameter 250mm x width 600mm

Roll temperature: 120 deg.C

In comparative example 5, since the film had a high haze and could not be used as an optical film because of the use of an embossing roll, the retardation increase rate before and after the heat-forming, the chemical resistance, and the bending resistance were not evaluated.

[ TABLE 1 ]

[ TABLE 2 ]

Claims

1. A film, characterized by:

comprising an aromatic polycarbonate resin having a terminal structure represented by the formula (1),

the aromatic polycarbonate resin has a viscosity average molecular weight of 17000 to 40000,

the thickness of the film is 20 to 150 μm,

the surface roughness Ra of the film is less than 0.7 μm,

in the formula (1), R¹Represents an alkyl group having 8 to 36 carbon atoms or an alkenyl group having 8 to 30 carbon atoms, R²Each independently represents a halogen atom, an alkyl group having 1 to 20 carbon atoms or an aryl group having 6 to 12 carbon atoms, n represents an integer of 0 to 4, and represents a bonding site with another site.

2. The film of claim 1, wherein:

the glass transition temperature of the film is 115-142 ℃.

3. The film of claim 1 or 2, wherein:

the aromatic polycarbonate resin has a viscosity average molecular weight of 30000 to 40000.

4. The film of claim 1 or 2, wherein:

the aromatic polycarbonate resin has a viscosity average molecular weight of 17000 or more and less than 30000.

5. The film of any one of claims 1 to 4, wherein:

the surface roughness Ra of the film is less than 0.1 mu m.

6. The film of any one of claims 1 to 5, wherein:

the film has a haze of 10% or less.

7. The film of any one of claims 1 to 6, wherein:

the film has a retardation Re of 25nm or less with respect to light having a wavelength of 543 nm.

8. The film of any one of claims 1 to 7, wherein:

it is a monolayer film.

9. A multilayer body characterized by:

having a film according to any one of claims 1 to 8 and at least 1 further layer.

10. A multi-layer body as claimed in claim 9, wherein:

the other layer comprises an adhesive layer.

11. A transparent conductive film characterized in that:

sequentially comprises a protective layer, an adhesive layer, a substrate and an electrode layer,

at least one of the substrate and the protective layer is the film according to any one of claims 1 to 8.