CN107405908A - Stacked film and its manufacture method - Google Patents

Abstract

A kind of various functions with as stacked film of present invention offer and stacked film that can be to be processed in high yield and in high precision with high mechanical properties, in various manufacturing procedures.The stacked film of the present invention is characterised by：It is the A layers formed by crystalline polyester and the alternately laminated stacked film for adding up to more than 11 layers and being formed of the B layers formed by the thermoplastic resin different from foregoing crystalline polyester, and the Young's modulus of the orientation direction of principal axis (the maximum direction of Young's modulus) of foregoing stacked film is more than 6GPa.

Description

Stacked film and its manufacture method

Technical field

The present invention relates to stacked film and its manufacture method.

Background technology

For thermoplastic resin film, especially biaxially oriented polyester film, due to engineering properties, electrical property, chi The excellent property such as very little stability, the transparency and chemical proofing, therefore, in a variety of use such as magnetic recording material, packaging material Widely used in way as base material film.

On the other hand, in polyester film, the alternately laminated stacked film formed of different resins has been used.For such stacking For film, can turn into have can not be by the film for the special function that the film of individual layer obtains, for example, can enumerate：Improve tear The resistance to tearing film of intensity is (with reference to patent document 1.), the infrared reflection film of reflection infrared ray is (with reference to patent document 2.) and Polarization optical reflection film with polarization reflective character is (with reference to patent document 3.) etc..

However, in stacked film as described above, due to forming the different alternately laminated structures formed of resin, so with list The film of layer is compared, and thickness is laminated by it to be influenceed and mechanical strength, the such tendency of dimensional stability decline be present.If stacked film Mechanical strength, dimensional stability decline, for example, with other various films, Component composition, implement punching, severing, coating and lamination During Deng processing to form functional membrane, cause film to deform, be broken due to the power applied to film, exist following such Problem：The decline of machining accuracy, yield when processing and the optical characteristics of obtained film, quality decline etc.；Or When product etc. the adjoint unfavorable condition of change in size occurs for actual installation.

Prior art literature

Patent document

Patent document 1:No. 3960194 publications of Japanese Patent No.

Patent document 2:No. 4310312 publications of Japanese Patent No.

Patent document 3:Japanese Unexamined Patent Publication 2014-124845 publications

The content of the invention

Invent problem to be solved

Therefore, it is an object of the invention to solve above-mentioned problem, and it is an object of the present invention to provide a kind of have as stacked film Various functions and with high mechanical properties, dimensional stability, in various manufacturing procedures can with high yield, it is high-precision The stacked film of unfavorable condition does not occur when being processed and actually using for degree.

Means for solving the problems

The present invention is completed to solve above-mentioned problem, and stacked film of the invention is characterised by, it is by crystallizing Property the A layers that are formed of the polyester and B layers that are formed by the thermoplastic resin different from foregoing crystalline polyester are alternately laminated adds up to 11 The stacked film more than layer formed, the Young's modulus of the orientation direction of principal axis (the maximum direction of Young's modulus) of foregoing stacked film is 6GPa More than.

It is 1 μm, ripple in beam diameter for foregoing stacked film according to the preferred embodiment of the stacked film of the present invention A length of 1390cm^-1Polarization Raman spectrum in, the peak intensity I max in the maximum direction of reflectivity with and its vertical direction peak The ratio between intensity I min I max/I min are more than 5.

According to the preferred embodiment of the stacked film of the present invention, in the carboxylic acid composition for forming foregoing crystalline polyester, comprising More than 90mol% naphthalenedicarboxylic acid.

According to the present invention stacked film preferred embodiment, foregoing stacked film orientation direction of principal axis and with foregoing orientation The either direction in the vertical direction of direction of principal axis, the absolute value of the linear expansion coefficient at less than more than 40 DEG C 50 DEG C of temperature are Less than 10ppm/ DEG C.

According to the preferred embodiment of the stacked film of the present invention, by entering relative to the orientation direction of principal axis comprising foregoing stacked film The reflectivity when incident angle for penetrating the parallel polarized light component in face is 10 ° is designated as R1, and will include orientation relative to foregoing When reflectivity when the incident angle of the vertical polarized light component of the plane of incidence of direction of principal axis is 10 ° is designated as R2, during wavelength 550nm Reflectivity meets following formula (2) and formula (3).

R2 (550)≤40% (2)

R1 (550) >=70% (3)

According to the present invention stacked film preferred embodiment, foregoing stacked film by differential calorimetry (hereinafter referred to as DSC) in the first heating curve obtained, stacked film has melting peak, also, when the melting peak summit temperature is designated as into Tm, There is exothermic peak in less than more than Tm-110 DEG C Tm-60 DEG C of scope.

According to the present invention stacked film preferred embodiment, the orientation direction of principal axis of foregoing stacked film with and be orientated direction of principal axis same Simultaneously the ratio between interior vertical Young's modulus in direction is more than 2.

According to the present invention stacked film preferred embodiment, foregoing stacked film orientation direction of principal axis 100 DEG C of temperature when heat Shrinkage stress is below 1MPa.

According to the present invention stacked film preferred embodiment, foregoing stacked film orientation direction of principal axis 100 DEG C of temperature when TMA Absolute value be less than 0.5%.

According to the preferred embodiment of the stacked film of the present invention, foregoing stacked film is surveyed using means of differential scanning calorimetry measure (DSC) The melting peak from aforementioned thermoplastic resin B obtained is below 5J/g.

According to the preferred embodiment of the stacked film of the present invention, foregoing A layers and foregoing B layers meet following conditions.

A layers：Formed by the aromatic polyester using dicarboxylic acid component and diol component as main composition, foregoing dicarboxyl 80~100mol% in sour composition 100mol% is NDA, 80 in foregoing glycols composition 100mol%~ 100mol% is ethylene glycol.

B layers：Formed by the aromatic polyester using dicarboxylic acid component and diol component as main composition, foregoing dicarboxyl 40~75mol% in sour composition 100mol% is NDA, and 25~60mol% is selected from M-phthalic acid, 1,8- At least one of naphthalenedicarboxylic acid and 2,3- naphthalenedicarboxylic acid composition, 80~100mol% in foregoing glycols composition 100mol% are Ethylene glycol.

According to the preferred embodiment of the stacked film of the present invention, foregoing stacked film can be wound and shape along the axis of orientation of foregoing stacked film Into film roll.

According to the preferred embodiment of the film roll of the present invention, the width of foregoing stacked film is more than 1000mm.

The manufacture method of stacked film of the present invention is characterised by, for the A layers that are formed by crystalline polyester and by with it is preceding State that B layers that the different thermoplastic resin of crystalline polyester is formed are alternately laminated to add up to more than the 11 layers unstretching films formed, with 2~ 5 times of multiplying power is stretched along film length direction, is then stretched with 2~5 times of multiplying power along film width, and then again Stretched with 1.3~4 times of multiplying power along film length direction.

The effect of invention

By the present invention, a kind of stacked film is can obtain, the stacked film has high mechanical properties, dimensional stability, is making It is punched, severing, the processing such as coating and lamination or can be suitably used when being used for various functions film, and energy Play the effect used unfavorable condition can not occur during actual installation.

The present invention stacked film due to being the stacked film with high Young's modulus, thus as suitable for various optical films, The film of engineering film etc..

Embodiment

Next, the stacked film and its manufacture method of the present invention are described in detail.

The stacked film of the present invention is by crystalline polyester (following, sometimes referred to as crystalline polyester A.) formed layer (A layers) With by the thermoplastic resin different from foregoing crystalline polyester (following, sometimes referred to as thermoplastic resin B.) formed layer (B Layer) it is alternately laminated add up to 11 layers of stacked film formed above.

Herein, so-called crystalline polyester A, in particular to following polyester：According to JIS K7122 (1999), carry out differential and sweep Retouch calorimetry (following, sometimes referred to as DSC.), resin is heated to 300 DEG C from 25 DEG C with 20 DEG C/min of programming rate Temperature (1stRUN), after being kept for 5 minutes in this condition, followed by quenching, with the temperature as less than 25 DEG C, again with 20 DEG C/min of programming rate is warming up to 300 DEG C from 25 DEG C, in obtained 2ndRUN means of differential scanning calorimetry measure figure, by The hot Δ Hm of watery fusion that the peak area of melting peak is obtained is more than 15J/g polyester.More preferably watery fusion heat for 20J/g with On, more preferably more than 25J/g.

In addition, thermoplastic resin B is to show the optical characteristics or thermal characteristics different from the crystalline polyester A used in A layers Thermoplastic resin.Specifically refer to, 2 vertical directions for arbitrarily being selected in the face in stacked film and vertical with the face Any direction in direction, the thermoplastic resin of refractive index more than 0.01 or display and crystalline polyester A in DSC Different fusing point, the thermoplastic polyester of glass transition temperature.

In addition, it is so-called alternately laminated herein, refer to that A layers are laminated in a regular array in a thickness direction with B layers.Example Such as it is laminated using A (BA) n (n is natural number) regular arrangements represented.By as described above by the different tree of optical property Fat is alternately laminated, and so as to which interference reflection is presented, the interference reflection can be reflected by the pass of the difference and thickness of the refractive index of each layer It is the light of the wavelength of design.

In addition, by the way that the different resin of thermal characteristics is alternately laminated, so as to when manufacturing biaxially-stretched film, highly control The state of orientation of each layer is possibly realized, and control optical characteristics, mechanical property, heat shrinkability characteristic are possibly realized.

As the form of the preferable stacking of stacked film, can also enumerate：With the A layers formed by crystalline polyester A, by with B layers that the different thermoplastic resin B of crystalline polyester A are formed and by the heat different from crystalline polyester A and thermoplastic resin B Plastic resin C-shaped into C layers situation.In this case, it is formed as CA (BA) n, CA (BA) nC and A (BA) nCA (BA) m The composition in outermost layer or intermediate layer is laminated in Deng layer C.

In addition, when the number of plies of stacking is less than 11 layers, different thermoplastic resins is stacked each to Film making properties, mechanical properties etc. Physical property impacts, thus such as manufacture of biaxially-stretched film sometimes becomes difficult, is combined with other inscapes and system is made During product, it may occur however that unfavorable condition.

On the other hand, as the stacked film of the present invention, stacked film that alternately laminated total more than 11 layers of layer forms In the case of, compared with stacked film of the number of plies less than 11 layers, each thermoplastic resin can be equably configured, accordingly, it is capable to make Film making properties, machine Tool physical property stabilizes.In addition, with the increase of the number of plies, show the tendency for the growth that can suppress the orientation in each layer, for example, such as by The tear-resistant intensity that surface tension is brought improves so, becomes to be easily controlled mechanical property, heat shrinkability characteristic, in addition, presenting dry The imparting for relating to the special optical characteristics of reflection function etc is possibly realized.The number of plies of stacking is preferably more than 100 layers, further Preferably more than 200 layers.For film, when being laminated more than 100 layers, also being turned into the light in the wide region of high reflectance reflection can Can, and then, during more than 200 layers of stacking, for example, being capable of substantially 400~700nm of reflection wavelength whole visible rays.In addition, The number of plies of stacking does not have the upper limit, but as the number of plies increases, is likely to become the maximization of manufacture device and the system that complication is adjoint The reason for causing this increase, therefore, in fact, being usage range within 10000 layers.

For the stacked film of the present invention, the Young's modulus of the orientation direction of principal axis of stacked film is needed for more than 6GPa.This Locate the orientation direction of principal axis of so-called stacked film, refer to determine the Young's modulus of film every 10 ° of ground change direction in film surface, should Young's modulus turns into maximum direction.Young's modulus is the index of power required when representing film initial deformation, by making Young Modulus is high, so as to stacking when being used in the manufacturing procedures such as punching, severing, coating and lamination or as functional membrane During film applying power, can also suppress to deform, suppress film deformation it is adjoint processing it is bad, use when performance change become to hold Easily.

It is preferred that the Young's modulus of the orientation direction of principal axis of stacked film is more than 8GPa, more preferably more than 10GPa.With Young Modulus increase, stacked film become to be unlikely to deform, for example, the control of processing conditions when punching, severing, coating and lamination etc. are processed Scope broadens, and therefore, can not only suppress to process bad, and the performance of the product obtained for raising is also useful.In order to Young's modulus is improved, as described later, in addition to the selection of resin, is also realized by the manufacture method of film.

In addition, in the case of the number of plies of individual layer or several layers of degree, the Young's modulus of the orientation direction of principal axis of stacked film is During more than 6GPa, due to the orientation intensity of its resin, the tendency that stacked film becomes fragile be present, operability be able to may also decline.

On the other hand, as the present invention, the A layers formed by crystalline polyester A from by different with crystalline polyester A In the case of alternately laminated total more than the 11 layers stacked film formed of B layers that thermoplastic resin B is formed, even if Young's modulus is More than 6GPa, because it is laminated the interfacial tension of interface or the buffering effect by the thermoplastic resin B B layers formed, so as to Do not damage and operatively improve Young's modulus, and then in the manufacturing procedures such as punching, severing, coating and lamination or conduct When functional membrane using to stacked film applying power, the effect for the deformation that can also be inhibited.

In addition, in the stacked film of the present invention, the orientation direction of principal axis of stacked film with and its vertical direction in the same face The ratio between Young's modulus is more than 2 and preferable mode.Wanting merely to carry by the manufacture method of the selection of resin, film In the case of the ratio between high Young's modulus, for the stacked film for direction in the face in stacked film with impartial Young's modulus, The limit be present in Young's modulus.This is due to the intensity that Young's modulus depends on forming the orientation of the resin of stacked film, thus is being thought Improve and be orientated the size that will influence Young's modulus strongly to which kind of degree on the direction of Young's modulus.

On the other hand, continuously enter in manufacturing procedures such as punching, severing, coating and laminations, especially with the film of web-like In the process of row processing, the Young's modulus for improving stacked film length direction is effective for the stabilisation of manufacturing procedure.Therefore, By make the orientation direction of principal axis of stacked film with and the ratio between its vertical Young's modulus in direction in the same face be more than 2, can enter One step improves the Young's modulus of axis of orientation side, the Young's modulus in the maximum direction (the orientation direction of principal axis of stacked film) of Young's modulus into Become easy for more than 6GPa.More preferably stacked film orientation direction of principal axis with and its vertical direction in the same face Young mould The ratio between amount is more than 3, and in this case, the Young's modulus of the orientation direction of principal axis of stacked film, which turns into more than 10GPa, also becomes easy.

For the present invention stacked film for, beam diameter be 1 μm, wavelength 1390cm^-1Polarization Raman spectrum in, The peak intensity I max in the maximum direction of reflectivity with and its vertical direction the ratio between peak intensity I min I max/I min it is preferred For more than 5.The maximum direction of so-called reflectivity herein, refers to：Make polarized light component relative to stacked film the plane of incidence be 0 °, It is 0 ° to make incident angle, and in stacking film surface, when changing direction every 10 ° of ground and determining reflectivity, reflectivity shows maximum Direction.

In addition, the wavelength observed in Raman spectrum is polarized is 1390cm^-1Peak belong to the CNC telescopic bands of naphthalene nucleus, Can by the peak intensity I max in the maximum direction of reflectivity with and its vertical direction the ratio between peak intensity I min I max/I Min, determine the state of orientation of naphthalene nucleus.Wavelength 1390cm^-1The I max/I min at place are preferably more than 5.5, and more preferably more than 6.

Wavelength 1390cm^-1When the I max/I min at place are more than 5, represent that naphthalene nucleus is equably orientated, as a result, take by height Xiang Hua, Young's modulus can be improved.For wavelength 1390cm^-1For the I max/I min at the place upper limit, from prevent due to by comprising The A layers that the crystalline polyester A of naphthalenedicarboxylic acid is formed take from the B layers that are formed by the thermoplastic resin B different with crystalline polyester A Caused by becoming big to state, crystalline difference, from the viewpoint of the deterioration of interlayer adaptation, higher limit is preferably 20, more Preferably 10, particularly preferably less than 7.Wavelength 1390cm^-1The I max/I min at place can pass through the combination of A layers and the resin of B layers Selection and film forming condition adjust.

In addition, the present invention stacked film in, beam diameter be 1 μm, wavelength 1615cm^-1Polarization Raman spectrum in, The peak intensity I max in the maximum direction of reflectivity with and the ratio between the peak intensity I min I max/I min in its vertical direction be 4 Above is preferred embodiment.

The wavelength 1615cm observed in Raman spectrum is polarized^-1Peak belong to the C=C telescopic bands of phenyl ring, can pass through The peak intensity I max in the maximum direction of reflectivity with and its vertical direction the ratio between peak intensity I min I max/I min, survey Determine the state of orientation of phenyl ring.Wavelength 1615cm^-1The I max/I min at place are preferably more than 4.5, and more preferably more than 5.Wavelength 1615cm^-1When the I max/I min at place are more than 4, represent that phenyl ring is equably orientated, as a result, by highly orientedization, poplar can be improved Family name's modulus.

For wavelength 1615cm^-1For the I max/I min at the place upper limit, from preventing due to by the knot comprising naphthalenedicarboxylic acid A layers and the state of orientation of the B layers that are formed by the thermoplastic resin B different with crystalline polyester A that crystalline substance polyester A is formed, crystallize Property difference become big caused by, from the viewpoint of the deterioration of interlayer adaptation, the upper limit is preferably less than 20, more preferably 10 with Under, particularly preferably less than 6.Wavelength 1615cm^-1The I max/I min at place can pass through A layers and the selection of the combination of the resin of B layers And film forming condition adjusts.The example of its optimal combination is as described above.

In addition, the present invention stacked film in, beam diameter be 1 μm, wavelength 1390cm^-1Polarization Raman spectrum in, The peak intensity I max in the maximum direction of reflectivity with and its vertical direction the ratio between peak intensity I min I max/I min it is preferred For more than 5.

In the stacked film of the present invention, orientation direction of principal axis and the direction vertical with the orientation direction of principal axis of stacked film in stacked film Either direction, the absolute value of linear expansion coefficient during 40 DEG C~50 DEG C of temperature needed for less than 10ppm/ DEG C.So-called line is swollen Swollen coefficient, be represent change temperature when film size change easiness index, by the absolute value for making thermal coefficient of expansion Diminish, so as in manufacturing procedures such as punching, severing, coating and laminations or as functional membrane in use, even if stacked film When temperature changes, can also suppress the deformation of film, suppress film deformation it is adjoint processing it is bad, use when performance change Become easy.

It is preferred that in the orientation direction of principal axis of stacked film and the either direction in the direction vertical with the orientation direction of principal axis of stacked film, line The absolute value of the coefficient of expansion is less than 5ppm/ DEG C.Decline with the absolute value of thermal coefficient of expansion, relative to the stacking of temperature change The deformation of film diminishes, for example, the control range of processing conditions during processing broadens, therefore, can not only suppress to process it is bad, and The performance of product obtained for raising, or size distortion when suppressing actual use is also useful.It is swollen in order to reduce heat The absolute value of swollen coefficient, as described later, in addition to the selection of resin, also realized by the manufacture method of stacked film.

In addition, in the case of the number of plies of individual layer or several layers of degree, 40 DEG C~50 DEG C of the orientation direction of principal axis of stacked film When the absolute value of linear expansion coefficient during temperature is less than 10ppm/ DEG C, due to the orientation intensity of its resin, there is what film became fragile Tendency, operability may also reduce.On the other hand, as the present invention, the A layers formed by crystalline polyester A with by with it is preceding The feelings for the stacked film stated alternately laminated total more than 11 layers of the B layers that the different thermoplastic resin B of crystalline polyester A are formed and formed Under condition, even if the absolute value of linear expansion coefficient during 40 DEG C~50 DEG C of temperature is less than 10ppm/ DEG C, because it is laminated interface The interfacial tension at place, the buffering effect by the thermoplastic resin B B layers formed, operatively drop low linear expansion so as to not damage Coefficient, and then to stacked film in the manufacturing procedures such as punching, severing, coating and lamination or when conduct functional membrane uses During applying power, the effect for the deformation that can also be inhibited.

In addition, in the stacked film of the present invention, thermal shrinkage stress during 100 DEG C of temperature of the orientation direction of principal axis of stacked film is Below 1MPa and preferable mode.Thermal shrinkage stress is the power to be worked when representing to change temperature in the direction that stacked film shrinks Size index, by reducing thermal shrinkage stress, so as to heat when in use to stacked film when, can suppress deform, can suppress Process bad, stacked film performance change.Thermal shrinkage stress during more preferably 100 DEG C of temperature is below 0.5MPa, this feelings Under condition, in manufacturing procedure or when actually using, it can also suppress the thermal deformation of stacked film.

In addition, in the stacked film of the present invention, the TMA of following formula (1) expression of the orientation direction of principal axis of stacked film absolute value In 100 DEG C of temperature be less than 0.5% and preferable.In following formula (1), L and Δ L represent layer during 25 DEG C of temperature respectively The displacement of the length of the orientation direction of principal axis of folded film and the length of the stacked film from 25 DEG C of temperature during change temperature.TMA is table Show the index of the ratio of contraction or the elongation of stacked film when changing temperature, by reducing TMA absolute value, when in use to layer It can suppress to deform during folded film heating, can suppress to process bad, film performance change.It is preferred that the absolute value of TMA during 100 temperature Also it is less than 0.5%, in this case, in manufacturing procedure or when actually using, can also suppresses the thermal deformation of film.

TMA=| Δ L/L | × 100% (1)

In the present invention, stacked film can form the film roll formed along the axis of orientation winding of stacked film.As described above, punching, In the process that the manufacturing procedures such as severing, coating and lamination, the film especially with web-like are continuously processed, stacked film is improved The Young's modulus of length direction is effective to the stabilisation of manufacturing procedure, is wound into by the axis of orientation obtained along stacked film Film roll, so as to when the stacked film using the present invention obtains product, will also be readily obtained the product of high-quality.

In order to obtain such film roll, formed by the flow direction in the orientation direction of principal axis of stacked film and the manufacturing process of film It is preferred embodiment that angle, which is less than 10 °,.Angle formed by flow direction in the orientation direction of principal axis of stacked film and the manufacturing process of film Spend for less than 10 ° when, by by obtained stacked film continuously wound into rolls, so as in punching, severing, coating and lamination etc. In the process that manufacturing procedure, the film especially with web-like are continuously processed, the flowing of direction of principal axis and manufacturing procedure is orientated Direction becomes identical, and therefore, the stabilisation of manufacturing procedure becomes easy.

In fact, the coiling direction of film roll can be considered as to the flow direction in film manufacturing process, and in the product of reality, layer The orientation direction of principal axis of folded film and the coiling direction angulation of film roll are less than 10 °.

In the stacked film of the present invention, the A layers preferably formed by crystalline polyester A are outermost layer.In this case, crystallinity Polyester A turns into outermost layer, therefore, can be with the knot of polyethylene terephthalate film, poly (ethylene naphthalate) film etc Crystalline substance polyester film similarly operates, and manufactures biaxially-stretched film.Not for crystalline polyester but by for example noncrystalline resin When the thermoplastic resin B of formation turns into outermost layer, when being operated in the same manner as crystalline polyester film and obtaining biaxially-stretched film, sometimes Produce because be film-made bad, prima facie deterioration caused by the adhesion in the manufacturing equipments such as roller, fixture (clip) the problems such as.

As workable crystalline polyester A in the present invention, preferable use passes through with aromatic dicarboxylic acid or aliphatic Dicarboxylic acids and glycol are polyester obtained from the polymerization of the monomer of main composition.

Herein, as aromatic dicarboxylic acid, for example, terephthalic acid (TPA), M-phthalic acid, phthalic acid, 1 can be enumerated, 4- naphthalenedicarboxylic acids, 1,5- naphthalenedicarboxylic acids, 2,6- naphthalenedicarboxylic acids, 4,4 '-biphenyl dicarboxylic acid, 4,4 '-diphenyl ether dioctyl phthalate, 4, 4 '-diphenyl sulfone dioctyl phthalate etc..As aliphatic dicarboxylic acid, for example, can enumerate adipic acid, suberic acid, decanedioic acid, dimeric dibasic acid, Dodecanedioic acid and cyclohexane cyclohexanedimethanodibasic and their ester derivant etc..These sour compositions can be used only a kind, also can and with 2 kinds More than.

Especially, the carboxylic acid composition as the crystalline polyester A used in the stacked film for forming the present invention, rolled over from height is presented Penetrate rate, improve Young's modulus it is such from the viewpoint of, preferably use terephthalic acid (TPA) and NDA.Due to benzene two Formic acid, NDA include the aromatic ring with high symmetry, therefore, by being orientated it and crystallizing, so as to same Shi Shixian highs index of refraction and high Young's modulus become easy.Especially, 2,6- are included in the carboxylic acid composition for forming crystalline polyester A In the case of naphthalenedicarboxylic acid, by increasing the volume ratio of aromatic ring, so as to which high Young's modulus can be realized, and due to energy Industrially universally obtain, thus the product of low cost can be turned into.

Further preferably in the carboxylic acid composition for forming crystalline polyester, the NDA comprising more than 80mol%. By the naphthalenedicarboxylic acid comprising more than 80mol%, so as in the manufacture of stacked film, by being stretched and being heat-treated, hold Change places and carry out oriented crystalline, high Young's modulus becomes easy.

In addition, as diol component, for example, ethylene glycol, 1,2-PD, 1,3-PD, neopentyl glycol, 1 can be enumerated, 3- butanediols, 1,4- butanediols, 1,5- pentanediols, 1,6-HD, 1,2- cyclohexanedimethanols, 1,3- cyclohexanedimethanols, Double (4- hydroxyethoxyphenyls) propane of 1,4 cyclohexane dimethanol, diethylene glycol, triethylene glycol, PAG, 2,2-, Isobide (isosorbate) and spiral shell glycol etc..Wherein, it is main using ethylene glycol from the viewpoint of polymerization is easily such Composition is preferred embodiment.

So-called main component herein, refers to more than the 80mol% in diol component.More preferably more than 90mol%.These Diol component can be used only a kind, also and can use two or more.Also carboxylic acid such as copolymerizable a part of hydroxybenzoic acid etc..

As workable thermoplastic resin B in the present invention, polyethylene, polypropylene, poly- (4-methyl-1-pentene) can be used Deng chain polyolefin；As the Romp polymer of norborneol alkenes, addition polymer, the addition copolymerization with other olefines The alicyclic polyolelfin of thing；Polyamide, aromatic polyamides, the poly-methyl methacrylates such as nylon 6, nylon 11, nylon 12, nylon66 fiber Ester, polyvinyl chloride, polyvinylidene chloride, polyvinyl alcohol, polyvinyl butyral resin, EVAc, polyacetals, Polyglycolic acid, polystyrene, styrene copolymerized polymethyl methacrylate, makrolon；PTT, gather Ethylene glycol terephthalate, polybutylene terephthalate (PBT), poly- 2,6- (ethylene naphthalate)s, PLA, poly- amber The polyester such as acid butyl ester；Polyether sulfone, polyether-ether-ketone, Noryl, polyphenylene sulfide, PEI, polyimides, polyarylate, TFE, trifluoro-ethylene resin, trifluorochlorethylene resin, tetrafluoraoethylene-hexafluoropropylene copolymer and poly- inclined difluoro second Alkene etc..

In these, in addition to from the viewpoint of intensity, heat resistance, the transparency and versatility, used from A layers From the viewpoint of crystalline polyester A adaptation and stackability are such, preferably using polyester.Either copolymer is still for they Mixture can be used.

In the stacked film of the present invention, in the case that thermoplastic resin B is polyester, preferable use passes through with aromatic series dicarboxyl Sour composition and/or aliphatic dicarboxylic acid composition and diol component are polyester obtained from the polymerization of the monomer of main composition. Herein, as aromatic dicarboxylic acid composition, aliphatic dicarboxylic acid composition and diol component, can suitably use in crystalline polyester The composition enumerated in A.

In the stacked film of the present invention, thermoplastic resin B is preferably main using aromatic dicarboxylic acid composition and diol component The aromatic polyester of constituent.Especially, as preferred mode, in dicarboxylic acid component 100mol%, 40~ 75mol% is NDA, and 25~60mol% is in M-phthalic acid, 1,8- naphthalenedicarboxylic acids, 2,3- naphthalenedicarboxylic acids Composition, in diol component 100mol%, 80~100mol% is ethylene glycol.

For M-phthalic acid, 1,8- naphthalenedicarboxylic acids and 2,3- naphthalenedicarboxylic acid, according to its molecular skeleton, having makes point The effect of subchain bending, as a result, orientation when reducing thermoplastic resin B crystallinity, stretching is possibly realized.As a result, manufacture is drawn When stretching film, the increase of the adjoint refractive index of oriented crystalline of B layers can be suppressed, can easily produce with by crystalline polyester A shapes Into A layers refringence (in the case of polarization light reflective properties, for refringence with the axis of orientation of A layers).As a result, especially It is in the case where polarization reflective character is presented, higher optical characteristics is presented and is possibly realized.

It is that amorphous resin is also preferred as thermoplastic resin B to obtain the stacked film with interference reflection function Mode.Amorphous resin is not susceptible to be orientated, therefore, can suppressed compared with crystalline resin when manufacturing biaxially-stretched film By the increase of the adjoint refractive index of the oriented crystalline of the thermoplastic resin B B layers formed, can easily produce with being gathered by crystallinity The refringence for the A layers that ester A is formed.Especially, in the case of setting heat treatment step when manufacturing stretched film, the effect becomes Significantly.

In stretching process in caused orientation, caused orientation can fully relax in heat treatment step in B layers, energy Maximize the refringence of the A layers with being formed by crystalline polyester.

So-called amorphous resin herein, refer to following resins：According to JIS K7122 (1999), with 20 DEG C/min of heating Speed by resin from 25 DEG C of temperature for being heated to 300 DEG C (1stRUN), after being kept for 5 minutes in this condition, followed by rapid It is cold, below the temperature as 25 DEG C, carry out again with 20 DEG C/min of programming rate from room temperature to 300 DEG C of temperature Heating, in obtained 2ndRUN means of differential scanning calorimetry measure figure, the watery fusion heat obtained by the peak area of melting peak Δ Hm is below 5J/g resin, does not show the resin at the peak equivalent to crystalline fusion more preferably.

In addition, in order to obtain the stacked film with interference reflection function, as thermoplastic resin B, further preferably using having The crystalline resin of more than 20 DEG C lower than crystalline polyester A fusing point of fusing point.In this case, in heat treatment step, pass through Temperature between thermoplastic resin B fusing point and crystalline polyester A fusing point implements heat treatment, so as in heat treatment step In fully make its mitigation, can make with by the crystalline polyester A A layers formed refringence maximize.It is preferred that crystalline polyester A Difference with thermoplastic resin B fusing point is more than 40 DEG C.In this case, the range of choice of the temperature in heat treatment step becomes Width, therefore, the promotion of thermoplastic resin B orientation mitigation, the control of the orientation of crystalline polyester can become easier to.

As crystalline polyester A and thermoplastic resin B preferable combination, the poor absolute value of both SP values is preferably It is 1.0 following.When the poor absolute value of SP values turns into less than 1.0, the splitting of A layers and B layers becomes to be not susceptible to.More preferably tie Crystalline substance polyester A and thermoplastic resin B is formed by the combination for providing same basic framework.

So-called basic framework herein, refer to the repeat unit for forming resin.For example, using carboxylic acid composition only by 2,6- naphthalenes two The PEN of formic acid composition or the principal component using 2,6- naphthalenedicarboxylic acids as carboxylic acid composition (include in carboxylic acid composition More than 80% NDA) polyethylene naphthalate copolymers as crystalline polyester A in the case of, as Thermoplastic resin B, crystalline polyester A knot is preferably less than using non-crystalline polyethylene naphthalate copolymers or fusing point Crystalline substance polyethylene naphthalate copolymers.

In addition, in order to obtain the stacked film with interference reflection function, preferred thermoplastic resin B glass transition temperature More than 10 DEG C lower than crystalline polyester A glass transition temperature.In this case, in stretching process, in order to crystallinity When polyester is stretched and uses most suitable draft temperature, the orientation in thermoplastic resin B will not be in progress, and therefore, may be such that The refringence of A layers with being formed by crystalline polyester is big.More preferably thermoplastic resin B glass transition temperature compares crystallinity Polyester A glass transition temperature is low more than 20 DEG C.

It is used to obtain the suitable manufacture method of the stacked film of the present invention described later, sometimes thermoplastic resin B takes Easily it is in progress to crystallization, cannot get desired interference reflection function, but by making thermoplastic resin B glass transition temperature Degree is lower than crystalline polyester A glass transition temperature more than 20 DEG C, so as to suppress oriented crystalline.

Furthermore it is possible to the degree addition various additives in thermoplastic resin deteriorate its characteristic, such as antioxygen Agent, heat-resisting stabilizing agent, weathering stabilizers, ultra-violet absorber, organic lubricant, pigment, dyestuff, organic or inorganic it is micro- Grain, filler, antistatic agent and nucleator etc..

In the stacked film of the present invention, it is preferred that will be parallel relative to the plane of incidence of the orientation direction of principal axis comprising stacked film Reflectivity when being 10 ° of the incident angle of polarized light component be designated as R1, and by relative to the axis of orientation side for including stacked film To the incident angle of the vertical polarized light component of the plane of incidence be 10 ° when reflectivity be designated as R2 when, it is anti-when wavelength is 550nm The rate of penetrating meets following formula (2) and formula (3).By meeting following formula (2) and formula (3), so as to assign reflection a certain polarization Light, the such polarization reflective character of another polarised light of transmission.

In order to be met the film of following formulas (2), the A layers and B layers of the orientation direction of principal axis of stacked film can be passed through Refringence is less than 0.02, the combination of more preferably less than 0.01, more preferably less than 0.005 resin is adjusted Section.In addition, in order to be met the film of following formulas (3), the direction vertical with the orientation direction of principal axis of stacked film can be passed through A layers and B layers refringence be more than 0.08, the group of more preferably more than 0.1, more preferably more than 0.15 resin Selection and the film forming condition of conjunction and be adjusted.The example of its most suitable combination is as described above.

R2 (550)≤40% (2)

R1 (550) >=70% (3).

In the stacked film of the present invention, it is preferred that in the first heating curve in DSC, stacked film has melting peak Tm, Also, there is exothermic peak in the scope below more than Tm-110 DEG C Tm-60 DEG C of the melting peak summit temperature.It is above-mentioned in order to present Polarized light property, each layer refractive index control become important, this cause orientation and it is crystalline control become important.The control In, be orientated in one direction by the A layer heights that make to be formed by crystalline polyester A so that differently- oriented directivity with and its is vertical Direction refringence increase., it is necessary to make the one party of B layers and the refractive index of A layers, (mainly refractive index is low on the other hand Direction) refringence increase consistent, with the opposing party (the mainly high direction of refractive index), the orientation of control B layers, crystallinity Become important.

The present inventor etc. has made intensive studies, and as a result finds, as the index of control B layers, passes through first in DSC In heating curve, stacked film has melting peak Tm, also, below more than Tm-110 DEG C Tm-60 DEG C of the melting peak summit temperature In the range of have exothermic peak, thus, can obtain high optical characteristics.

The exothermic peak be represent B layers crystallize caused by heat release peak, thus, turn into B layers orientation, crystallization The index of property.In the case of in the absence of the exothermic peak, in film making process, oriented crystalline is carried out B layers, or, crystallinity It is very low, etc., cause in desired scope, optical characteristics not decline with the relation of the refractive index of A layers.

In addition, even if exothermic peak be present, its more than Tm-110 DEG C outside less than Tm-60 DEG C of scope when, B layers excessively take To, anisotropy is presented, or, crystallinity extremely reduces；Etc., cause with the relation of the refractive index of A layers not desired Scope, optical characteristics decline.Therefore, in stacked film of the invention, less than Tm-60 DEG C of scope has and put more than Tm-110 DEG C Thermal spike, this is necessary for obtaining high optical characteristics.

As the method for forming less than the Tm-60 DEG C stacked film with exothermic peak more than Tm-110 DEG C, can enumerate following Method：It is foregoing preferable form to make A layers and B layers；In manufacture method described later, make temperature, multiplying power in stretching process And draw speed is preferable scope.These methods are it is also preferred that combination is a variety of and carries out.

Thermal discharge in the preferred exothermic peak of stacked film of the present invention is more than 0.1J/g below 10J/g.Thermal discharge is more preferably For more than 0.5J/g below 5J/g, more preferably more than 1.5J/g below 4J/g.Thermal discharge Tm-60 more than Tm-110 DEG C When outside the scope below DEG C, B layers are excessively orientated, and anisotropy is presented, or, crystallinity extremely reduces；Etc., cause and A layers Refractive index relation not in desired scope, optical characteristics declines.In the stacked film of the present invention, by making in exothermic peak Thermal discharge is more than 0.1J/g below 10J/g, so as to can obtain bloom characteristic.

The stacked film preferred molten peak temperature Tm of the present invention is more than 255 DEG C.Melting peak temperature be more preferably 258 DEG C with On.In order to meet the scope of above-mentioned melting peak temperature, resin that preferred scope is selected in foregoing resin can be enumerated Mode, thus, optical characteristics can be improved, and the high film of heat resistance can be formed.

Next, the preferable manufacture method of the stacked film of the following explanation present invention.

In addition, the stepped construction of workable stacked film is available with Japanese Unexamined Patent Publication 2007-307893 public affairs in the present invention The same method of content described in [0053]~[0063] section of report is easily realized.

First, crystalline polyester A and thermoplastic resin B is prepared in the form of particle etc..For particle, exist as needed After being dried in hot blast or under vacuum, supplied into extruder respectively.In extruder, for heating the tree melted Fat, using gear pump etc., the extrusion capacity of resin is homogenized, by filter etc., foreign matter, the resin being modified etc. are removed. These resins are sent into multilayer stacking device.

As multilayer stacking device, multi-manifold, feed head (feed block), static mixer etc. can be used, be The composition of the present invention is effectively obtained, preferably using the feed head with the fine slit of more than 11.By using so Feed head, type will not be become very large so as to device, therefore, the few foreign caused by heat deterioration, even if stacking number is very When more, high-precision stacking can be also carried out.In addition, also technology significantly increases the stacking precision of width than ever.In addition, Using the device, the thickness of each layer can be adjusted by the shape (length, width) of slit, therefore, arbitrary thickness can be achieved.

Moreover, the laminated sheet to be spued from die head is extruded in the cooling bodies such as curtain coating drum, be cooled solidification, thus, can Obtain casting films.Now, it is preferred that using electrodes such as wire, banding, needle-like or knife-like, by electrostatic force, make the piece of discharge Material is sealed at cooling body, is quenched and makes its solidification.In addition, as making the sheet material of discharge be sealed at the method for cooling body, from The method and the use of the method for nip rolls (nip roll) is also preferred embodiment that the device of slit-shaped, point-like and planar is blown.

It is preferred that the casting films obtained in the manner described above are carried out biaxial stretch-formed.It is so-called biaxial stretch-formed herein, refer to along length Degree direction and width stretch to film.

In addition, the preferable biaxial stretch-formed method as the stacked film for obtaining the present invention is, it is necessary to along film length side After being stretched to the multiplying power with 2~5 times, stretched along film width with 2~5 times, and then again along film length direction Stretched with 1.3~4 times.Its details is as described below.

For obtained casting films, first, stretched along its length.Stretching along its length is generally using roller All speed differences and implement.The stretching can be carried out with 1 stage, in addition, it is possible to use multiple rollers pair, carried out with the multistage.Make For the multiplying power of stretching, according to the different and different of the species of resin, but preferably 2~5 times.1st time along its length The purpose of stretching is：In order to improve Uniform Tension during subsequent stretching along film width, and required for setting The orientation of bottom line.Therefore, make stretching ratio for multiplying power more than 5 times when, stretched in film width described later and at this Implement after process along its length when redrawing, cannot get the film of sufficient stretching ratio sometimes.In addition, stretching ratio is low When 2 times, it is impossible to assign the orientation of bottom line required during stretching, and also produce thickness on film length direction sometimes Inequality, cause quality decline.In addition, the glass transition as draft temperature, preferably the crystalline polyester A of composition stacked film The temperature of temperature~+30 DEG C of glass transition temperature.

For the monadic stretching membrane obtained in the manner described above, sided corona treatment can implemented to it, at flame as needed After the surface treatment such as reason and corona treatment, easy slip, easy-adhesion and static electricity resistance are assigned to it by coating online Etc. function.

Next, monadic stretching membrane is stretched in the width direction.For the stretching of width, generally, make With stenter, while clamping the both ends of film with fixture, while being conveyed, stretched in the width direction.Times as stretching Rate, according to the different and different of the species of resin, it is often preferred that 2~5 times.The purpose stretched in the width direction is, if Be set to assign it is subsequent along film length direction stretch when high stretch required for bottom line orientation.Therefore, drawing is made Stretch multiplying power for multiplying power more than 5 times when, when redrawing, sometimes cannot along film length direction what the then process was implemented The film of sufficient stretching ratio.In addition, when stretching ratio is less than 2 times, thickness is produced on film width in stretching sometimes Inequality, cause quality decline.In addition, draft temperature is preferably in the glass transition temperature for the crystalline polyester A for forming stacked film Between the crystallized temperature of+30 DEG C of~glass transition temperature or glass transition temperature~crystalline polyester.

Next, obtained biaxially-stretched film is stretched along its length again.The stretching along its length Generally implement using all speed differences of roller.The stretching can be carried out with 1 stage, in addition, it is possible to use multiple rollers pair, with more Stage is carried out.The multiplying power of stretching is different and different according to the species of resin, but preferably 1.3~4 times.Above-mentioned 2nd time along length The purpose of degree direction stretching is to be orientated as strongly as possible on film length direction, by as described above again along its length Stretched, so that resin is orientated strongly, as a result, can make stacked film orientation direction of principal axis Young's modulus for 6GPa with The linear expansion coefficient in direction (the orientation direction of principal axis of stacked film) upper, Young's modulus is maximum is less than 10ppm/ DEG C.Especially, edge The stretching ratio in direction is higher, can more improve Young's modulus, or more can suppress linear expansion coefficient, make Young's modulus for 10GPa with The absolute value of linear expansion coefficient that is upper, making less than more than 40 DEG C 50 DEG C also becomes easy for less than 5ppm/ DEG C.In addition, stretching temperature Degree is preferably glass transition temperature~+80 DEG C of the glass transition temperature for the crystalline polyester A for forming stacked film.

It is excellent in order to assign flatness and dimensional stability for having carried out biaxial stretch-formed film in the manner described above The temperature in stenter below draft temperature melt point above is selected in be heat-treated.By being heat-treated, so as to not only may be used Promote oriented crystalline, obtain the effect of Young's modulus increase, and along with the promotion of oriented crystalline, dimensional stability Improve, as a result, make direction (the orientation direction of principal axis of stacked film) that Young's modulus is maximum and vertical with the orientation direction of principal axis of stacked film Direction either direction 40 DEG C~50 DEG C of temperature when linear expansion coefficient absolute value for less than 5ppm/ DEG C as can Energy.In addition, thermal shrinkage stress during 100 DEG C of temperature of orientation direction of principal axis is set to turn into below 1MPa, make the 100 of orientation direction of principal axis DEG C temperature when TMA absolute value be also possibly realized as less than 0.5%.After being heat-treated in the manner described above, uniformly After ground Slow cooling, it is cooled to normal temperature and is wound.In addition, as needed, when can also carry out Slow cooling after heat treatment, Carry out relaxation processes etc..

Before the stacked film obtained using manufacture method as described above can form not only Young's modulus height but also have satisfaction The formula (2) and the stacked film of the polarization reflective character of (3) stated.Because in the stretching in the film length direction of the 2nd time, Can make by the orientation of the crystalline polyester A A layers formed on film length direction it is stronger, as a result, the refractive index in film length direction Difference is produced between the refractive index of the vertical film width in film length direction.And then by selecting amorphous resin to make For thermoplastic resin B or glass transition temperature, the fusing point that can relax orientation in stretching process and heat treatment step is selected to deposit In the crystalline polyester A and thermoplastic resin B of difference combination, so as to suppress thermoplastic resin B orientation, polarization can be assigned Reflective character.

(assay method of characteristic and the evaluation method of effect)

The assay method of characteristic in the present invention and the evaluation method of effect are as described below.

(1) stacking number：

The Rotating fields of stacked film have cut out section using slicer by using transmission electron microscope (TEM) observation Sample and obtain.That is, it is in accelerating potential using transmission electron microscope H-7100FA types ((strain) Hitachi system) The cross-section photograph of film is shot under conditions of 75kV, determines Rotating fields and each thickness degree.According to circumstances, in order to improve contrast, profit With having used RuO₄、OsO₄Deng staining technique.It is in addition, most thin according to the thickness in whole layers in piece image that is ingested The thickness of layer (film layer), in the case where thin film layer thickness is less than 50nm, is observed by 100,000 times of enlargement ratio, Thin film layer thickness be more than 50nm and less than 500nm in the case of, observed by 40,000 times of enlargement ratio, in film layer In the case that thickness is more than 500nm, observed by 10,000 times of expansion multiplying power.

(2) computational methods of thickness and the number of plies：

Using scanner (Canon's (strain) CanoScan D1230U processed), above-mentioned (1) item is taken in picture size 720dpi In obtained TEM photograph images.Will in the form of bitmap file (bitmap file) (BMP) or compressed image file (JPEG) Image is stored in PC, next, using image processing software Image-Pro Plus ver.4 (retailers：プラ ネ ト ロ Application (strain)), this document is opened, carries out graphical analysis.For image analysis processing, with vertical thickness outline mode, The mean flow rate in thickness direction position and folded region between 2 lines of width is read in the form of numeric data Relation.

Using table software for calculation (Excel 2000), for position (nm) and the data of brightness, using sampling step 2 ( Data acquisition 2) is carried out every rejecting, then implements the numerical value processing of 5 rolling averages.And then by the obtained brightness cycle Property change data carry out differential, using VBA (Visual Basic for Applications) program, read differential song The maximum and minimum of line, using the interval in the great region of adjacent brightness and minimum region as 1 layer of thickness, calculate Thickness.Implement the operation for every photo, calculate the thickness and the number of plies of whole layers.

(3) Young's modulus：

Stacked film is cut into length 150mm × width 10mm strip, as sample.Use cupping machine (オ リ エ Application テ ッ Network テ Application シ ロ Application UCT-100), distance is 50mm between making incipient extension chuck, makes draw speed for 300mm/ points Clock, carry out tension test.Implement measure under 23 DEG C of room temperature, the atmosphere of relative humidity 65%, asked by obtained load-strain line Go out Young's modulus.5 measure are respectively carried out for each sample, are evaluated with their average value.

(4) the orientation direction of principal axis of stacked film：

Change direction every 10 ° of ground in film surface and determine the Young's modulus of stacked film, the Young's modulus is turned into maximum Orientation direction of principal axis of the direction as stacked film.

(5) linear expansion coefficient：

Stacked film is cut into length 25mm × width 4mm strip along its orientation direction of principal axis, as sample.Use TMA Testing machine (セ イ U ー イ Application ス Star Le メ Application Star TMA/SS6000), distance is 15mm between making incipient extension chuck, makes drawing Constant expansion force is 29.4mN, and experiment built-in temperature is increased to 150 DEG C of temperature with 5 DEG C/min from 25 DEG C in this case, TMA measure is carried out to the orientation direction of principal axis of stacked film.By obtained TMA- temperature curves, when obtaining 40 DEG C~50 DEG C of temperature Linear expansion coefficient.

(6) thermal shrinkage stress：

Stacked film is cut into length 25mm × width 4mm strip along its orientation direction of principal axis, as sample.Use TMA Testing machine (セ イ U ー イ Application ス Star Le メ Application Star TMA/SS6000), constant distance is 15mm between making tensioning chuck, herein Under state, built-in temperature will be tested and is increased to from 25 DEG C 150 DEG C of temperature with 5 DEG C/min, for the axis of orientation side of stacked film To measure thermal shrinkage stress.By obtained stress-temperature curve, thermal shrinkage stress is obtained.

(7)TMA：

Stacked film is cut into length 25mm × width 4mm strip along its orientation direction of principal axis, as sample.Use TMA Testing machine (セ イ U ー イ Application ス Star Le メ Application Star TMA/SS6000), distance is 15mm between making incipient extension chuck, makes drawing Constant expansion force is 29.4mN, and experiment built-in temperature is increased to 150 DEG C of temperature with 5 DEG C/min from 25 DEG C in this case, TMA measure is carried out to the orientation direction of principal axis of stacked film.By obtained TMA- temperature curves, TMA is obtained.

(8) to the measure of the reflectivity and transmissivity of the incident light with polarized light component：

Turn into the orientation direction of principal axis center on maximum line segment from the length of orientation direction of principal axis, sample is cut out with 5cm × 5cm Product.Using having used Hitachi's spectrophotometer (U-4100Spectrophotomater) incidental integrating sphere It is basic to form, it is measured on the basis of the secondary blank of the aluminum oxide subsidiary by device.It is vertical using the orientation direction of principal axis of stacked film Nogata is to sample to be arranged to the rear of integrating sphere.In addition, subsidiary グ ラ ン テ ー ラ company system polaroids are set, it is incident Make polarized light component polarization for 0 and 90 ° of rectilinearly polarized light, 250~1500nm of measure wavelength reflectivity.

Condition determination is as described below.Slit is set as 2nm (visible)/automatically control (infrared), gain (gain) is set It is set to 2, is measured with sweep speed 600nm/ minutes, obtains the reflectivity that azimuth is 0~180 degree.Carrying out sample During reflection measurement, interfere to eliminate caused by the reflection from the back side, applied with マ ジ ッ Network イ Application キ (registration mark) It is black.

In addition, for the sample cut out according to the same manner, not blacking and determine transmissivity according to the same manner, by obtaining Transmissivity data, using following formula, obtain the extinction ratio at wavelength 550nm.

Extinction ratio=T2/T1

(herein, T1 represents when incident angle is 0 °, parallel relative to the plane of incidence of the orientation direction of principal axis comprising stacked film Polarized light component transmissivity, T2 represent incident angle be 0 ° when, entering relative to the orientation direction of principal axis comprising stacked film Penetrate the transmissivity of the vertical polarized light component in face.)

(9) peak intensity of Raman spectrum is polarized than I max/I min：

Use laser Raman spectrometer Jovin Yvon company system T-64000, measure polarization Raman spectrum.For stacked film For, using the maximum direction of the reflectivity determined in above-mentioned (4) item as I max, using perpendicular direction as I Min, in a manner of the cut surface of all directions turns into aspect of measure, section is cut out using slicer.For polarizing Raman spectrum, The situation that the polarizing axis of laser from specimen cross section is consistent with the axis of homology of film is as parallel condition, by the thickness with stacked film The consistent situation in degree direction is measured as perpendicular condition.For measure, for the central portion of each layer, change position 3 points of measure is carried out, using average value as measured value.Detailed condition determination is as described below.

Mode determination：Microscopic Raman

Object lens：×100

Beam diameter：1μm

Cross slit：100μm

Light source：Ar+ laser/514.5nm

Laser power：15mW

Diffraction grating：Spectrograph 600gr/mm

It is scattered：21 angstroms/mm of Single

Slit：100μm

Detector：CCD/Jobin Yvon 1024×256.

For wavelength 1390cm^-1And wavelength 1615cm^-1When polarization Raman spectrum peak intensity than I max/I min and Speech, the 1390cm on the CNC telescopic bands from naphthalene nucleus as obtained from the measure for polarizing Raman spectrum^-1Peak intensity and The 1615cm of C=C telescopic bands from phenyl ring^-1Peak intensity, by make aspect of measure be I max directions section sample and make survey The peak intensity for determining face for the sample in the section in I min directions calculates ratio.

(10) melting enthalpy and glass transition temperature：

Sampled from the stacked film of measure, using differential thermometric analysis (DSC), according to JIS-K-7122 (1987), The DSC curve of determination sample is measured.For experiment, 290 DEG C of temperature is warming up to from 25 DEG C with 20 DEG C/min, The melting enthalpy and glass transition temperature of measurement now.Device used etc. is as described below.

Device：セ イ コ ー Electricity industry (strain) system " ロ ボ ッ ト DSC-RDC220 "

Data analysis " デ ィ ス Network セ ッ シ ョ Application SSC/5200 "

Sample quality：5mg.

(11) processability：

The film of web-like is directed into clicker press machine, it is 500mm to make length, using relative to film width be 95% it is wide to length Rectangle mould, implement punching.In addition, make the punching of length direction at intervals of 40mm.Carry out following A, B and C evaluations.Will A and B are as qualified.

A：Film can continuously be conveyed, processed not brokenly.

B：Although the fracture of part occurs for film, the continuous conveying of length direction can be carried out, can be continuously processed.

C：Film is broken completely, fails to carry out the Continuous maching of length direction.

(12) installation experiment：

From the position of film width central portion, with length direction 1450mm × width 820mm sizes, conduct is cut out The stacked film of sample.Next, in the type liquid crystal TV LHD32K15JP backlights of Ha イ セ Application ス ジ ャ パ Application Co. Ltd. system 32 On, set with the order of 50% diffusing panel, micro-lens sheet, polarization light reflector and Polarizer, in 50 DEG C and 85 DEG C of temperature Under, by visual observation come evaluate carry out 12 hours heat resistant tests after polarization light reflector flatness.

The evaluation of flatness is judged with following A, B and C.Using A as qualified.

A：In 50 DEG C and 85 DEG C of temperature, outward appearance has no problem

B：It is problematic in 50 DEG C of temperature, outward appearance.

(13) containing ratio of naphthalenedicarboxylic acid：

By the A layers formed by crystalline polyester of stacked film be dissolved in deuterated hexafluoroisopropanol (HFIP) or HFIP with it is deuterated The in the mixed solvent of chloroform, composition analysis is carried out using 1H-NMR and 13C-NMR.

Embodiment

(embodiment 1)

As crystalline polyester A, the poly- naphthalenedicarboxylic acids of 2,6- that fusing point is 266 DEG C, glass transition temperature is 122 DEG C are used Glycol ester (PEN).In addition, as thermoplastic resin B, the glass transition temperature for the amorphous resin without fusing point is used Spend and be total to 2,6- naphthalenedicarboxylic acid spiral shell diol esters 25mol%, terephthalic acid (TPA) 25mol% and ethylene glycol 50mol% for 103 DEG C PEN (copolymerization PEN1) is copolymerized obtained from poly-.

The crystalline polyester A of preparation and thermoplastic resin B are put into 2 single screw extrusion machines respectively, in 290 DEG C Temperature carries out melting mixing.Next, crystalline polyester A and thermoplastic resin B is set to be filtered by the disc type of 5 FSS types respectively After device (leaf disk filter), while measured with gear pump, while being closed with the stacked laminator of slit number 11 Stream, obtains layered product obtained from alternately laminated 11 layers in a thickness direction.The method of layered product is made according to Japanese Unexamined Patent Publication Method described in 2007-307893 publications (0053)~(0056) section is carried out.

Herein, the length of slit and interval are all constant.It is 6 layers, thermoplasticity that obtained layered product, which has crystalline polyester A, Resin B is 5 layers, the alternately laminated stepped construction formed in a thickness direction.In addition, make inside as mouth mold broadening ratio, Value obtained from the length of film width at the film width length of mouth mold lip divided by the inflow oral area of mouth mold turns into 2.5.The width of obtained casting films is 600mm.

The casting films for heating to obtain with the roller group for the temperature for having been set to 120 DEG C, then, with the temperature for having been set to 135 DEG C The roller of degree is stretched to 3.0 times along film length direction, is then cooled down for the time being.The monadic stretching membrane that will be obtained in the manner described above It is directed into stenter, after being preheated with the hot blast of 115 DEG C of temperature, 3.0 is stretched along film width in 135 DEG C of temperature Times, biaxially-stretched film is obtained in the form of film roll.The width of the biaxially-stretched film obtained herein is 1500mm.

In addition, heat biaxially-stretched film with the roller group of the temperature for having been set to 120 DEG C, then, with having been set to 160 DEG C The roller of temperature is stretched to 3.0 times along film length direction, trims the both ends of film, using film of the film width as 1000mm, length for 200m The form of volume obtains target stacked film.

Obtained stacked film shows such physical property as shown in table 1, shows that high Young's modulus and low line are swollen in the MD direction Swollen coefficient (40~50 DEG C).In addition, display interference as caused by crystalline polyester A and thermoplastic resin B refractive index difference Reflection characteristic.For the stacked film of the present invention, when being processed into product or in actual use, it can use well.

(embodiment 2)

Using the device that slit number is 101 as the stacked laminator used, in addition, grasp similarly to Example 1 Make, obtain stacked film.

Obtained stacked film shows such physical property as shown in table 1, similarly to Example 1, is shown on film length direction High Young's modulus and low linear expansion coefficient (40~50 DEG C).In addition, refraction of the display by crystalline polyester A and thermoplastic resin B Interference reflection characteristic caused by rate difference, compared with Example 1 compared with the high polarization reflective character of display.For the stacked film For, can accurately stably continuous production, and in actual use, can also have no problem ground when being processed into product Use.

(embodiment 3)

Using the device that slit number is 201 as the stacked laminator used, in addition, grasp similarly to Example 1 Make, obtain stacked film.

Obtained stacked film shows such physical property as shown in table 1, similarly to Example 1, shows Gao Yang in the MD direction Family name's modulus and low linear expansion coefficient (40~50 DEG C).In addition, refringence of the display by crystalline polyester A and thermoplastic resin B Interference reflection characteristic caused by different, compared with Example 2 compared with the high polarization reflective character of display, for polarised light can be used as anti- Penetrate the level that component uses.For the stacked film, when being processed into product, can accurately stably continuous production, and And in actual use, use with also having no problem.

(embodiment 4)

Using the device that slit number is 801 as the stacked laminator used, in addition, grasp similarly to Example 1 Make, obtain stacked film.Obtained stacked film shows such physical property as shown in table 1, similarly to Example 1, shows in the MD direction Show high Young's modulus and low linear expansion coefficient (40~50 DEG C).In addition, folding of the display by crystalline polyester A and thermoplastic resin B Interference reflection characteristic caused by rate difference is penetrated, compared with Example 3 compared with the high polarization reflective character of display, as polarised light Reflecting member, there is extraordinary performance.For the stacked film, when being processed into product, accurately can stably it connect Continuous production, and in actual use, use with also having no problem.

(embodiment 5)

Multiplying power when making again to stretch biaxially-stretched film along film length direction is 2.5 times, in addition, with implementation Example 4 similarly operates, and obtains stacked film.Obtained stacked film shows such physical property as shown in table 1, display high Young's modulus and Low linear expansion coefficient (40~50 DEG C).In addition, similarly to Example 4, high polarization reflective character is shown, is reflected as polarised light Component, there is extraordinary performance., can be accurately stably continuous raw when being processed into product for the stacked film Production, and in actual use, use with also having no problem.

(embodiment 6)

Multiplying power when making again to stretch biaxially-stretched film along film length direction is 2.2 times, in addition, with implementation Example 4 similarly operates, and obtains stacked film.Obtained stacked film shows such physical property as shown in table 1, display high Young's modulus and Low linear expansion coefficient (40~50 DEG C).For the stacked film, when being processed into product under given conditions, also can continuously it give birth to Production, and in actual use, use with also having no problem.

(embodiment 7)

Multiplying power when making again to stretch biaxially-stretched film along film length direction is 2.0 times, in addition, with implementation Example 4 similarly operates, and obtains stacked film.Obtained stacked film shows such physical property as shown in table 1, display high Young's modulus and Low linear expansion coefficient (40~50 DEG C).For the stacked film, when being processed into product under given conditions, also can continuously it give birth to Production, and in actual use, use with also having no problem.

(embodiment 8)

After being stretched along its length to biaxially-stretched film again, 180 DEG C of temperature has been heated to by being delivered to So as to implement to be heat-treated in baking oven, in addition, operate similarly to Example 4, obtain stacked film.Obtained stacked film is shown Such physical property as shown in table 1, shows high Young's modulus and low linear expansion coefficient (40~50 DEG C).It is in addition, same with embodiment 4 Sample, high polarization reflective character is shown, as polarization light reflecting member, there is extraordinary performance.In addition, for obtained film For, compared with Example 4, can by thermal shrinkage stress at 100 DEG C of film length direction and TMA absolute value suppress compared with It is low, for the stacked film, when being processed into product under given conditions, can accurately stably continuous production, and In actual use, used with also having no problem under conditions of more harsh than embodiment 4.

(embodiment 9)

After being stretched along its length to biaxially-stretched film again, 220 DEG C of temperature has been heated to by being delivered to So as to implement to be heat-treated in baking oven, in addition, operate similarly to Example 4, obtain stacked film.Obtained stacked film is shown Such physical property as shown in table 2, shows high Young's modulus and low linear expansion coefficient (40~50 DEG C).It is in addition, same with embodiment 4 Sample, high polarization reflective character is shown, as polarization light reflecting member, there is extraordinary performance.In addition, for obtained layer For folded film, compared with Example 4, thermal shrinkage stress at 100 DEG C of film length direction and TMA absolute value can be suppressed ground It is relatively low, for the stacked film, when being processed into product under given conditions, can accurately stably continuous production, and And in actual use, used with also having no problem under conditions of more harsh than embodiment 4.

(embodiment 10)

As crystalline polyester, the use of fusing point is 240 DEG C, glass transition temperature be 118 DEG C by NDA PEN (copolymerization PEN2) is copolymerized obtained from 50mol%, spiral shell glycol 5mol% and ethylene glycol 45mol% copolymerization, in addition, with Embodiment 4 similarly operates, and obtains stacked film.Obtained stacked film shows such physical property as shown in table 2, shows high Young mould Amount.For the stacked film, when being processed into product under given conditions, also can continuous production, and actual use when, Also use with having no problem.

(embodiment 11)

Using copolymerization PEN2 as thermoplastic resin B, in addition, operate similarly to Example 4, obtain stacked film. Obtained stacked film shows such physical property as shown in table 2, similarly to Example 4, shows high Young's modulus.On the other hand, by In the poor small of crystalline polyester and thermoplastic resin B glass transition temperature, therefore, reflecting properties and embodiment 1 are equal Degree., can accurately stably continuous production, and actually using when being processed into product for the stacked film When, use with also having no problem.

(embodiment 12)

As crystalline polyester, the poly terephthalic acid second two that fusing point is 256 DEG C, glass transition temperature is 81 DEG C is used Alcohol ester (PET), as thermoplastic resin B, use the hexamethylene two that the glass transition temperature as amorphous resin is 78 DEG C Methanol copolymerization PET (copolymerization PET), in addition, operates, obtains stacked film similarly to Example 4.Obtained stacked film is shown Such physical property as shown in table 2, compared with comparative example 1~5, show high Young's modulus.For the stacked film, specific Under conditions of when being processed into product, also can continuous production, and in actual use, use with having no problem.On the other hand, Because crystalline polyester is PET, thus reflecting properties become lower than embodiment 4.

(embodiment 13)

As thermoplastic resin B, using glass transition temperature be 96 DEG C, using NDA 70mol% and M-phthalic acid 30mol% as dicarboxylic acid component, be copolymerized using ethylene glycol as diol component obtained from be copolymerized PEN (copolymerization PEN3), in addition, operates, obtains stacked film similarly to Example 4.Obtained stacked film is shown as shown in table 3 Such physical property, show high Young's modulus.For the stacked film, when being processed into product, energy continuous production, and in reality Border in use, use in which can also have no problem.

(embodiment 14)

After biaxial stretch-formed, the speed for making stretched film along its length is 400%/second, in addition, similarly to Example 13 Ground operates, and obtains stacked film.Obtained stacked film shows such physical property as shown in table 3, shows high Young's modulus.For the layer For folded film, when being processed into product, energy continuous production, and in actual use, use with also having no problem.In addition, Show that the extinction ratio of polarized light property is higher than embodiment 4, polarization light reflective properties are excellent.

(embodiment 15)

As thermoplastic resin B, using glass transition temperature be 90 DEG C, using NDA 50mol% and M-phthalic acid 50mol% is copolymerized PEN (altogether obtained from being copolymerized as dicarboxylic acid component, ethylene glycol as diol component Poly- PEN4), in addition, operate similarly to Example 4, obtain stacked film.Obtained stacked film shows such as shown in table 3 Physical property, show high Young's modulus.For the stacked film, when being processed into product, energy continuous production, and actually make Used time, use with also having no problem.In addition, the extinction ratio of display polarized light property is higher than embodiment 4, polarization light reflective properties are excellent It is different.

(embodiment 16)

As thermoplastic resin, using glass transition temperature be 98 DEG C, using NDA 75mol% and Phthalic acid 25mol% is copolymerized PEN (copolymerization obtained from being copolymerized as dicarboxylic acid component, ethylene glycol as diol component PEN5), in addition, operate similarly to Example 4, obtain stacked film.Obtained stacked film shows such as shown in table 3 Physical property, show high Young's modulus.For the stacked film, when being processed into product, energy continuous production, and actually using When, use with also having no problem.In addition, the extinction ratio of display polarized light property is higher than embodiment 4, polarization light reflective properties are excellent It is different.

(embodiment 17)

As thermoplastic resin B, using glass transition temperature be 103 DEG C, using NDA 80mol% and M-phthalic acid 20mol% is copolymerized PEN (altogether obtained from being copolymerized as dicarboxylic acid component, ethylene glycol as diol component Poly- PEN6), in addition, operate similarly to Example 4, obtain stacked film.Obtained stacked film shows such as shown in table 3 Physical property, show high Young's modulus.For the stacked film, when being processed into product, energy continuous production, and actually make Used time, use with also having no problem.In addition, the extinction ratio of display polarized light property is higher than embodiment 4, polarization light reflective properties are excellent It is different.

(embodiment 18)

As thermoplastic resin B, using glass transition temperature be 103 DEG C, using NDA 70mol% and 1,8- naphthalenedicarboxylic acids 30mol% is copolymerized PEN obtained from being copolymerized as dicarboxylic acid component, ethylene glycol as diol component (copolymerization PEN7), in addition, operates, obtains stacked film similarly to Example 4.Obtained stacked film is shown as shown in table 3 Such physical property, show high Young's modulus.For the stacked film, when being processed into product, energy continuous production, and in reality Border in use, use in which can also have no problem.In addition, the extinction ratio of display polarized light property is higher than embodiment 4, light reflective is polarized Can be excellent.

(embodiment 19)

As thermoplastic resin B, using glass transition temperature be 103 DEG C, using NDA 70mol% and 2,3- naphthalenedicarboxylic acid 30mol%, ethylene glycol are copolymerized PEN (copolymerization PEN8) obtained from being copolymerized as diol component, except this Outside, operate similarly to Example 4, obtain stacked film.Obtained stacked film shows such physical property as shown in table 3, display High Young's modulus.For the stacked film, when being processed into product, energy continuous production, and in actual use, can also not have Use problematicly.In addition, the extinction ratio of display polarized light property is higher than embodiment 4, polarization light reflective properties are excellent.

(comparative example 1)

As casting films, using the film of PEN individual layer, in addition, operate similarly to Example 4, obtain film.Obtain Film show such physical property as shown in table 2, similarly to Example 4, show high Young's modulus.On the other hand, due to without Stepped construction, thus special reflecting properties are not shown, and also compared with the film of embodiment 1, film becomes fragile, therefore, operability Decline.For the film, film fracture occurs when being processed into product, continuous production rate is poor.

(comparative example 2)

Using the device that slit number is 3 as the stacked laminator used, in addition, operate similarly to Example 1, Obtain stacked film.Obtained stacked film shows such physical property as shown in table 2, similarly to Example 1, shows on film length direction Show high Young's modulus.On the other hand, due to as little as 3 layers of the number of plies, thus the distinctive reflecting properties of stepped construction are not shown, Er Qieyu The film of embodiment 1 compares, and film becomes fragile, and therefore, operability somewhat declines.For the stacked film, when being processed into product Generation film is broken, and continuous production rate is poor.

(comparative example 3)

The casting films obtained with the roller group heating for the temperature for having been set to 120 DEG C in the way of similarly to Example 4, so Afterwards, 4.5 times are stretched to along film length direction with the roller for the temperature for having been set to 135 DEG C, are then cooled down for the time being.

The monadic stretching membrane obtained in the manner described above is directed into stenter, carried out with the hot blast of 135 DEG C of temperature After preheating, 4.5 times are stretched along film width in 150 DEG C of temperature, and then 220 DEG C have been heated to followed by being delivered to Implement heat treatment in baking oven.By trimming the both ends of obtained biaxially-stretched film, so as to be by 1500mm, length of film width The mode of 200m film roll obtains target stacked film.

Obtained stacked film shows such physical property as shown in table 2, compared with Example 4 compared with Young's modulus declines.For For the stacked film, film fracture occurs when being processed into product, continuous production rate is poor.

(comparative example 4)

The casting films obtained in the way of similarly to Example 4 are directed into stenter, with the heat of 135 DEG C of temperature After wind is preheated, stretch 5.0 times along film width in 150 DEG C of temperature, trim the both ends of film, so as to using film width as 2000mm web-like obtains 200m target stacked films.

Obtained stacked film shows such physical property as shown in table 2, compared with Example 4 compared with Young's modulus declines.Separately Outside, due to being to have the film of axis of orientation in the width of the film roll, therefore, the intensity of the winding direction of principal axis of film roll is very weak. For the stacked film, film fracture occurs when being processed into product, continuous production rate is poor.

(comparative example 5)

The casting films obtained with the roller group heating for the temperature for having been set to 120 DEG C in the way of similarly to Example 4, so Afterwards, using the roller for the temperature for having been set to 135 DEG C, 4.0 times is stretched to along film length direction, is trimmed, thus, obtains conduct Target be 500mm by film width, length be film roll that 200m stacked films are formed.

Obtained stacked film shows such physical property as shown in table 2, compared with Example 4 compared with Young's modulus declines.This Outside, along with the orientation of thermoplastic resin B caused by stretching, reflecting properties also decline to a great extent compared with embodiment.For this For stacked film, film fracture occurs when being processed into product, continuous production rate is poor.

[table 1]

Table 1

[table 2]

[table 3]

Claims (14)

1. a kind of stacked film, it is characterised in that it is the A layers that are formed by crystalline polyester and by different from the crystalline polyester Thermoplastic resin alternately laminated total more than 11 layers of B layers being formed form, the Young for being orientated direction of principal axis of the stacked film Modulus is more than 6GPa.

2. stacked film according to claim 1, it is characterised in that beam diameter be 1 μm, wavelength 1390cm^-1It is inclined Shake in Raman spectrum, the peak intensity I max in the maximum direction of reflectivity with and its vertical direction the ratio between peak intensity I min I Max/I min are more than 5.

3. stacked film according to claim 1, it is characterised in that in the carboxylic acid composition for forming crystalline polyester, comprising More than 90mol% naphthalenedicarboxylic acid.

4. stacked film according to claim 1 or 2, it is characterised in that orientation direction of principal axis and with the orientation direction of principal axis Either direction in vertical direction, the absolute value of the linear expansion coefficient at less than more than 40 DEG C 50 DEG C of temperature is 10ppm/ DEG C Below.

5. stacked film according to claim 1 or 2, it is characterised in that by relative to the incidence for including orientation direction of principal axis The reflectivity when incident angle of the parallel polarized light component in face is 10 ° is designated as R1, and will include axis of orientation relative to described In the case that reflectivity when the incident angle of the vertical polarized light component of the plane of incidence in direction is 10 ° is designated as R2, wavelength 550nm When reflectivity meet following formula (2) and formula (3),

R2 (550)≤40% (2)

R1 (550) >=70% (3).

6. stacked film according to claim 1 or 2, in the first heating curve obtained by differential calorimetry DSC, layer Folded film has melting peak, also, when the melting peak summit temperature is designated as into Tm, less than Tm-60 DEG C of the model more than Tm-110 DEG C There is exothermic peak in enclosing.

7. stacked film according to claim 1 or 2, it is characterised in that orientation direction of principal axis with and be orientated direction of principal axis same The ratio between vertical Young's modulus in direction is more than 2 in face.

8. stacked film according to claim 1 or 2, it is characterised in that be orientated thermal contraction during 100 DEG C of temperature of direction of principal axis Stress is below 1MPa.

9. stacked film according to claim 1 or 2, it is characterised in that TMA's when being orientated 100 DEG C of temperature of direction of principal axis Absolute value is less than 0.5%.

10. stacked film according to claim 1 or 2, it is characterised in that measured using means of differential scanning calorimetry measure DSC Melting peak from thermoplastic resin B is below 5J/g.

11. stacked film according to claim 1 or 2, it is characterised in that A layers and B layers meet following conditions,

A layers：Formed by the aromatic polyester using dicarboxylic acid component and diol component as main composition, the dicarboxylic acids into 80~100mol% in point 100mol% is NDA, 80~100mol% in the diol component 100mol% For ethylene glycol；

B layers：Formed by the aromatic polyester using dicarboxylic acid component and diol component as main composition, the dicarboxylic acids into 40~the 75mol% divided in 100mol% is NDA, and 25~60mol% is selected from M-phthalic acid, 1,8- naphthalenes two At least one of formic acid and 2,3- naphthalenedicarboxylic acid composition, 80~100mol% in the diol component 100mol% is second two Alcohol.

12. a kind of film roll, it is characterised in that it is along the stacked film by the stacked film any one of claim 1 or 2 Axis of orientation winding form.

13. film roll according to claim 12, it is characterised in that the width of stacked film is more than 1000mm.

A kind of 14. manufacture method of stacked film, it is characterised in that by the A layers formed by crystalline polyester and by with the crystallization Property the B layers that are formed of the different thermoplastic resin of polyester are alternately laminated adds up to more than the 11 layers unstretching films formed, with 2~5 times Multiplying power is stretched along film length direction, is then stretched with 2~5 times of multiplying power along film width, and then again with 1.3 ~4 times of multiplying power is stretched along film length direction.