CN105229501A

CN105229501A - Liquid crystal indicator, Polarizer and polaroid protective film

Info

Publication number: CN105229501A
Application number: CN201480027949.9A
Authority: CN
Inventors: 村田浩一; 佐佐木靖
Original assignee: Toyobo Co Ltd
Current assignee: Toyobo Co Ltd
Priority date: 2013-05-14
Filing date: 2014-05-08
Publication date: 2016-01-06
Anticipated expiration: 2034-05-08
Also published as: TW201446521A; JP2021192101A; JP2019091059A; CN105229501B; JP7264191B2; KR102385405B1; KR20160007548A; TWI530395B; JP7154138B2; WO2014185322A1; JPWO2014185322A1; JP2021002070A

Abstract

The polaroid protective film formed by mylar that also can suppress light leak when being configured under crossed nicols environment by 2 Polarizers is provided.A kind of polaroid protective film formed by mylar; it is characterized in that, being the percent thermal shrinkage in 45 degree of directions relative to film throughput direction and be the absolute values of difference of percent thermal shrinkage in-45 degree directions relative to film throughput direction being less than 0.4% of described polaroid protective film.

Description

Liquid crystal indicator, Polarizer and polaroid protective film

Technical field

The present invention relates to the polaroid protective film used in the Polarizer in liquid crystal indicator.

Background technology

The Polarizer used in liquid crystal indicator (LCD) is generally to be hold by 2 polaroid protective films and makes iodine forming the polaroid that polyvinyl alcohol (PVA) (PVA) etc. has dyeed; as polaroid protective film, usually use Triafol T (TAC) film.In recent years, require that Polarizer is thin layer with the slimming of LCD.But, for this reason thinning when being used as the thickness of TAC film of diaphragm, can there is to obtain enough physical strengths, and the problem that moisture-penetrability worsens.In addition, TAC film is very expensive, the strong alternative starting material needing cheapness.

Therefore, for the thin layer object of Polarizer, propose and use mylar to substitute TAC film, even if make as the thin method (patent documentation 1 ~ 3) that also can keep high-durability of polaroid protective film thickness.

Mylar is excellent in te pins of durability compared with TAC film, but different from TAC film, owing to having birefringence, time therefore used as polaroid protective film, there is the problem because optical distortion causes image quality to reduce.That is, have the mylar of birefringence owing to having the optical anisotropy (retardation) of regulation, when being therefore used as polaroid protective film, if from oblique observation, then can produce rainbow shape color spot, image quality reduces.Therefore, in patent documentation 1 ~ 3, have employed the countermeasure being reduced retardation by use copolyester as polyester.

In addition, Patent Document 4 discloses, by using white light-emitting diode as back light and then using the oriented polyester films with certain retardation as polaroid protective film, thus the uneven color of rainbow shape can be solved.

Patent Document 5 discloses; polaroid protective film is due to when manufacturing Polarizer or make the operation of gained Polarizer and liquid crystal cells compound etc. by a large amount of by heating process; therefore in order to have good dimensional stability; specifically, the shrinkage factor of the mylar preferably after the unrestricted thermal treatment of 120 DEG C × 30 minutes is less than 5% in film MD direction (film throughput direction), TD direction (thin-film width direction).

Prior art document

Patent documentation

Patent documentation 1: Japanese Unexamined Patent Publication 2002-116320 publication

Patent documentation 2: Japanese Unexamined Patent Publication 2004-219620 publication

Patent documentation 3: Japanese Unexamined Patent Publication 2004-205773 publication

Patent documentation 4:WO2011-162198

Patent documentation 5: Japanese Unexamined Patent Publication 2010-277028 publication

Summary of the invention

the problem that invention will solve

Polaroid protective film employs TAC film all the time, but also as stated in the Background Art, alternatively, the polaroid protective film formed by mylar receives publicity.Polarizer has the structure being clamped polaroid by 2 polaroid protective films.The discoveries such as the present inventor: prepare 2 following Polarizers and 2 Polarizers be configured under crossed nicols environment when; produce a small amount of light leak; there is the new problem of visual deterioration and so on sometimes, in 2 polaroid protective films of described Polarizer, at least one is mylar.A problem of the present invention is, provides polaroid protective film that can suppress above-mentioned a small amount of light leak, that formed by mylar.

for the scheme of dealing with problems

The present inventor etc. concentrate on studies to above-mentioned problem; found that: if the polaroid protective film formed by mylar, the percent thermal shrinkage that relative to film throughput direction is 45 degree of directions and be the absolute values of thermal shrinkage rate variance in-45 degree directions relative to film throughput direction be less than 0.4%, then can solve above-mentioned problem.

Representational the present invention as described below.

Item 1.

A kind of polaroid protective film formed by mylar; it is characterized in that, being the percent thermal shrinkage in 45 degree of directions relative to film throughput direction and be the absolute values of difference of percent thermal shrinkage in-45 degree directions relative to film throughput direction being less than 0.4% of described polaroid protective film.

Item 2.

Polaroid protective film according to item 1, wherein, the retardation of mylar is 4000 ~ 30000nm, Nz coefficient is less than 1.7.

Item 3.

Polaroid protective film according to item 1 or 2, wherein, the planar orientation degree of mylar is less than 0.13.

Item 4.

A kind of Polarizer, its both sides being included in polaroid are laminated with the formation of polaroid protective film, the polaroid protective film of at least one-sided polaroid protective film according to any one of item 1 ~ 3.

Item 5.

A kind of Polarizer, its both sides being included in polaroid are laminated with the formation of polaroid protective film,

A polaroid protective film is formed by triacetate cellulose film,

The polaroid protective film of another polaroid protective film according to any one of item 1 ~ 3.

Item 6.

A kind of liquid crystal indicator, its liquid crystal cells that there are back light, 2 Polarizers and be configured between aforementioned 2 Polarizers,

Backlight light source is the white light source with continuous luminous spectrum,

Aforementioned Polarizer is the formation being laminated with polaroid protective film in the both sides of polaroid,

The polaroid protective film of at least one according to any one of item 1 ~ 3 of the polaroid protective film of at least one being configured at the polaroid protective film of the Polarizer of incident light side and the Polarizer being configured at emergent light side.

Item 7.

Liquid crystal indicator according to item 6; wherein, the polaroid protective film of polaroid protective film according to any one of item 1 ~ 3 of the emergent light side of the polaroid protective film being configured at the incident light side of the Polarizer of aforementioned incident light side and the Polarizer being configured at aforementioned emergent light side.

the effect of invention

According to the present invention, can provide when 2 Polarizers are configured under crossed nicols environment, the liquid crystal indicator being inhibited, being suitable for obtaining having superior visibility of a small amount of light leak, the polaroid protective film that formed by mylar; And Polarizer.In addition, according to the present invention, light leak can be provided to be inhibited, visual excellent liquid crystal indicator.

Embodiment

1. polaroid protective film

Polaroid protective film of the present invention is formed by mylar; be the percent thermal shrinkage in 45 degree of directions relative to film throughput direction and be that the absolute values (following, sometimes also referred to as " the thermal shrinkage rate variance of vergence direction " or " thermal shrinkage rate variance ") of difference of percent thermal shrinkage in-45 degree directions are preferably less than 0.4% relative to film throughput direction.The absolute value of the difference of aforementioned hot shrinkage factor is preferably less than 0.3%, is more preferably less than 0.2%.The value of thermal shrinkage rate variance is more little more preferred, and therefore lower limit is 0%.Relative to film throughput direction be 45 degree direction and relative to film throughput direction be-45 degree directions certainly mutually orthogonal.In addition, the percent thermal shrinkage that the percent thermal shrinkage and-45 being 45 degree of directions relative to film throughput direction spends directions is all preferably less than 1.0%, is more preferably less than 0.8%, more preferably less than 0.6%.

Usually, in liquid crystal indicator, under 2 Polarizers are configured at crossed nicols environment.When 2 Polarizers are configured under crossed nicols environment, normally by light, but find: cause light to spill sometimes due to the thermal shrinkage rate variance of the vergence direction of polaroid protective film.Can think as following for its mechanism, but the present application is not limited to this.

Polarizer is normally by bonding and to manufacture via bonding agent by polaroid protective film and polaroid.In such bonding process, usual Polarizer carries out the thermal treatment of 10 minutes ~ about 60 minutes with the scope of 70 DEG C ~ 120 DEG C.When using film that the thermal shrinkage rate variance of vergence direction is large as polaroid protective film, during above-mentioned thermal treatment, mylar bends obliquely, and Polarizer itself also in an inclined direction produces small bending.Its result, polarizing axis is slightly out of shape at vergence direction, and when being configured under crossed nicols environment by such 2 Polarizers, the polarizing axis of 2 Polarizers not with the configuration of vertical relation, therefore produces a small amount of light leak across space.

As described in the background art, Patent Document 5 discloses, the percent thermal shrinkage on film throughput direction and thin-film width direction is the polaroid protective film formed by mylar of less than 5%.But, shown by above-mentioned mechanism, even if the percent thermal shrinkage in the percent thermal shrinkage of film throughput direction and thin-film width direction is little, if the thermal shrinkage rate variance of vergence direction is large, then also cannot suppresses the bending of the vergence direction of Polarizer, can light leak be produced.

The mylar used in polaroid protective film of the present invention can be obtained by arbitrary vibrin.Kind for vibrin has no particular limits, and can use dicarboxylic acid and glycol condensation and the arbitrary vibrin obtained.

As dicarboxylic acid component spendable in the manufacture of vibrin, such as can enumerate: terephthalic acid (TPA), m-phthalic acid, phthalic acid, 2, 5-naphthalene dicarboxylic acids, 2, 6-naphthalene dicarboxylic acids, 1, 4-naphthalene dicarboxylic acids, 1, 5-naphthalene dicarboxylic acids, biphenyl carboxylic acid, diphenoxyethanedicarboxylic acid, diphenyl sulfone carboxylic acid, anthracene dicarboxylic acid, 1, 3-cyclopentane dicarboxylic acid, 1, 3-cyclohexane dicarboxylic acid, 1, 4-cyclohexane dicarboxylic acid, six hydrogen terephthalic acid (TPA)s, six hydrogen m-phthalic acids, malonic acid, dimethyl malonic acid, succinic acid, 3, 3-diethyl succinic acid, glutaric acid, 2, 2-dimethylated pentanedioic acid, hexane diacid, 2-methyl hexane diacid, trimethyladipic acid, heptandioic acid, azelaic acid, dimer acid, decanedioic acid, suberic acid, dodecanedicarboxylic acid etc.

As diol component spendable in the manufacture of vibrin, such as can enumerate: ethylene glycol, propylene glycol, hexamethylene glycol, neopentyl glycol, 1,2-cyclohexanedimethanol, 1,4-cyclohexanedimethanol, decamethylene glycol, 1, ammediol, BDO, 1,5-PD, 1,6-hexanediol, 2,2-two (4-hydroxy phenyl) propane, two (4-hydroxy phenyl) sulfones etc.

For the dicarboxylic acid component and the diol component that form vibrin, can use one kind or two or more arbitrarily.As the suitable vibrin forming mylar, such as can enumerate: polyethylene terephthalate, PTT, polybutylene terephthalate, PEN etc., more preferably can enumerate: polyethylene terephthalate, PEN, these also can contain other copolymer compositions further.The transparency of these resins is excellent, and thermal characteristics, mechanical property are also excellent, can pass through stretch process easily control lag amount.Particularly, polyethylene terephthalate is large due to intrinsic birefringence, even if the thickness of film is thin also can obtain large retardation with comparalive ease, is therefore optimum starting material.

(the thermal shrinkage rate variance of vergence direction)

The thermal shrinkage rate variance of the vergence direction in the present invention refers to, when mylar is heated 30 minutes with 85 DEG C in water, relative to film throughput direction to be 45 ° of directions percent thermal shrinkage and be the absolute value of difference of percent thermal shrinkage in-45 ° of directions relative to film throughput direction.Specifically, before and after above-mentioned thermal treatment, mensuration is the length in 45 ° of directions and-45 ° of directions relative to the throughput direction of mylar, they are compared, obtain the percent thermal shrinkage for all directions, then, compare the percent thermal shrinkage in 45 ° of directions and the percent thermal shrinkage in-45 ° of directions, the difference of percent thermal shrinkage can be obtained.

The presence or absence of light leak can measure according to the assay method shown in embodiment described later.That is, 2 Polarizers are configured in the mode of the relation of crossed nicols, use spectrophotometer, the maximum transmission rate of light relative to aforementioned 2 Polarizers of the wavelength of 550 ~ 600nm can be measured.It should be noted that, in 2 Polarizers, polaroid and the mylar as polaroid protective film use are pasted in the orthogonal mode of main axis of orientation of the polarizing axis of polaroid and mylar.And, if the maximum transmission rate in the scope of aforementioned wavelength is less than 0.02%, then can be evaluated as light leak and exist in fact.

Below, from the view point of suppression rainbow spot, the preferred scope for the retardation of mylar, Nz coefficient, planar orientation degree is described.

(retardation)

The mylar used to the polaroid protective film used in the present invention is not particularly limited, and preferably has the retardation of 4000 ~ 30000nm.If retardation is more than 4000nm, then, when observing liquid crystal indicator from vergence direction, can interference color be suppressed, good visuality can be guaranteed.The preferred retardation of oriented polyester films is more than 4500nm, is then preferably more than 5000nm, is more preferably more than 6000nm, more preferably more than 8000nm, is further preferably more than 10000nm.

The upper limit of the retardation of mylar is preferably 30000nm.This be due to, even if use the mylar with its above retardation, in fact also cannot obtain the further of visuality and improve effect, along with the rising of retardation, the thickness of film also becomes quite thick, and the operability as industrial materials likely reduces.

The value of the retardation of oriented polyester films can be obtained according to the refractive index of known method mensuration biaxially oriented and thickness.In addition, the commercially available automatic double refraction detection devices such as KOBRA-21ADH (prince's measuring instrument Co., Ltd.) such as also can be used to measure.In any assay method, all measure the retardation under the wavelength of sodium D ray and 589nm.

(Nz coefficient)

The mylar used in polaroid protective film is on the basis of the scope of above-mentioned retardation, preferred | ny-nz|/| the Nz coefficient shown in ny-nx| is less than 1.7.Nz coefficient can be obtained as follows.Use molecular orientation meter (manufacture of prince's tester Co., Ltd., MOA-6004 type molecular orientation meter), obtain the axis of orientation direction of film, by Abbe refractomecer (ATAGOCO., LTD, manufacture, NAR-4T, mensuration wavelength 589nm) obtain the refractive index (ny, nx, wherein, ny > nx) of the twin shaft in axis of orientation direction and the direction orthogonal with it and the refractive index (nz) of thickness direction.Nx, ny, nz of so obtaining are substituted into | ny-nz|/| the formula shown in ny-nx|, Nz coefficient can be obtained.

Even if the retardation of mylar is 4000nm ~ 30000nm; when Nz coefficient is more than 1.7; a pair Polarizer both in use mylars as when polaroid protective film (such as; the polaroid protective film of the emergent light side of the polaroid protective film being configured at the incident light side of the Polarizer of incident light side and the Polarizer being configured at emergent light side is the situation of mylar); when observing liquid crystal indicator from vergence direction, still likely produce the worry of rainbow spot due to angle.Therefore, Nz coefficient is more preferably less than 1.65, more preferably less than 1.63.The lower limit of Nz coefficient is 1.2.This is because, the film obtaining being less than 1.2 in manufacturing technology is difficult.In addition, in order to keep the physical strength of film, the lower limit of Nz coefficient is preferably more than 1.3, is more preferably more than 1.4, more preferably more than 1.45.

(planar orientation coefficient)

The delay value of mylar and Nz coefficient are being controlled on the basis of above-mentioned particular range; by the planar orientation degree shown in (nx+ny)/2-nz is set to below particular value, both middle mylars that use of a pair Polarizer more positively can be eliminated completely as rainbow spot during polaroid protective film.Herein, the value of nx, ny and nz can be obtained by the method same with Nz coefficient.The planar orientation degree of oriented polyester films is preferably less than 0.13, is more preferably less than 0.125, more preferably less than 0.12.By planar orientation degree is set to less than 0.13, when observing liquid crystal indicator from vergence direction, the rainbow spot according to angle views can be eliminated more completely.Planar orientation degree is preferably more than 0.08, is more preferably more than 0.1.When planar orientation degree is less than 0.08, film thickness changes, and the value of retardation sometimes becomes uneven in pellicular front.

(retardation ratio)

For mylar, the ratio (Re/Rth) of its retardation (Re) and thickness direction retardation amount (Rth) is preferably more than 0.2, is more preferably more than 0.5, more preferably more than 0.6.This is because, the ratio (Re/Rth) of above-mentioned retardation and thickness direction retardation amount is larger, birefringent effect more increases isotropy, and becoming of the rainbow shape color spot caused due to viewing angle is difficult to produce.For 1 axle (1 rotational symmetry) film completely, the ratio (Re/Rth) of above-mentioned retardation and thickness direction retardation amount becomes 2.But as described later, along with close 1 axle (1 rotational symmetry) film completely, the physical strength in the direction vertical with direction of orientation obviously reduces.

Therefore, the upper limit of the ratio (Re/Rth) of the retardation of retardation and thickness direction is preferably less than 1.2, is more preferably less than 1.In order to suppress the rainbow shape color spot that caused by viewing angle to occur completely, the ratio (Re/Rth) of above-mentioned retardation and thickness direction phase differential there is no need to be 2, be less than 1.2 is sufficient.In addition, even if above-mentioned ratio is less than 1.0, field angle characteristic required by liquid crystal indicator (180 degree, left and right, upper and lower about 120 degree) also fully can be met.

(uneven thickness)

In order to suppress the variation of the retardation of mylar, the uneven thickness of preferred film is little.From this viewpoint, the uneven thickness of mylar be preferably less than 5%, more preferably less than 4.5%, be further preferably less than 4%, be particularly preferably less than 3%.

(film thickness)

The thickness of mylar is not particularly limited, is generally 15 ~ 300 μm, is preferably 15 ~ 200 μm.When film thickness is less than 15 μm, the anisotropy apparition of the mechanical characteristic of film, produces fracture, breakage etc. sometimes.The lower limit of particularly preferred thickness is 25 μm.On the other hand, when the upper limit of the thickness of polaroid protective film is more than 300 μm, the thickness of Polarizer becomes blocked up and not preferred.From the view point of the practicality as polaroid protective film, the upper limit of thickness is preferably 200 μm.The upper limit of particularly preferred thickness and general TAC film are 100 μm of equal extent.

(transmittance)

From the view point of the deterioration of the optical functional pigments such as the iodine pigment suppressed contained by polaroid, it is desirable that the transmittance of the wavelength 380nm of mylar is less than 20%.The transmittance of 380nm is more preferably less than 15%, more preferably less than 10%, be particularly preferably less than 5%.If aforementioned transmittance is less than 20%, then that optical functional pigment can be suppressed to cause because of ultraviolet is rotten.Transmittance is the value measured with vertical process relative to the plane of film, and spectrophotometer (such as, the spectrophotometer V-7100 of Japan Spectroscopy Corporation's manufacture) can be used to measure.

By the thickness of the kind of the compounding ultraviolet light absorber of suitable adjustment, concentration and film, the transmittance of the wavelength 380nm of oriented polyester films can be made to control below 20%.For ultraviolet light absorber used in the present invention, can be suitable for selecting known ultraviolet light absorber to use.As concrete ultraviolet light absorber, organic ultraviolet light absorber and inorganic UV absorber can be enumerated, from the view point of the transparency, preferred organic ultraviolet light absorber.

As organic ultraviolet light absorber, can enumerate: benzotriazole, benzophenone and cyclic imide base ester class etc. and their combination, as long as just there is no particular limitation in the scope of absorbance given to this invention.But, from the view point of permanance, particularly preferably benzotriazole, cyclic imide base ester class.When combinationally using ultraviolet light absorber of more than two kinds, due to can the ultraviolet of simultaneously stability wavelength separately, therefore UVA effect can be improved further.

As benzophenone ultraviolet absorbing agent, Benzotriazole Ultraviolet Stabilizer, and vinyl cyanide ultraviolet light absorber, such as can enumerate: 2-[2 '-hydroxyl-5 '-(methacryloxymethyl) phenyl]-2H-benzotriazole, 2-[2 '-hydroxyl-5 '-(methacryloxyethyl) phenyl]-2H-benzotriazole, 2-[2 '-hydroxyl-5 '-(methacryloxypropyl) phenyl]-2H-benzotriazole, 2, 2 '-dihydroxy-4, 4 '-dimethoxy-benzophenone, 2, 2 ', 4, 4 '-tetrahydroxybenzophenone, 2, 4-di-t-butyl-6-(5-chlorobenzotriazole-2-base) phenol, 2-(2 '-hydroxyl-3 '-the tert-butyl group-5 '-aminomethyl phenyl)-5-chlorobenzotriazole, 2-(5-chlorine (2H)-benzotriazole-2-base)-4-methyl-6-(tert-butyl group) phenol, 2, 2 '-di-2-ethylhexylphosphine oxide (4-(1, 1, 3, 3-tetramethyl butyl)-6-(2H-benzotriazole-2-base) phenol etc.As cyclic imide base ester class ultraviolet light absorber, such as can enumerate: 2,2 '-(1,4-phenylene) two (4H-3,1-benzoxazine-4-ketone), 2-methyl-3,1-benzoxazine-4-ketone, 2-butyl-3,1-benzoxazine-4-ketone, 2-phenyl-3,1-benzoxazine-4-ketone etc.Above-mentioned ultraviolet light absorber can only be used singly, or in combination of two or more kinds.

In mylar during compounding ultraviolet light absorber, oriented polyester films is made the sandwich construction of more than 3 layers, it is preferred for adding ultraviolet light absorber in the layer (that is, middle layer) beyond the outermost layer of film.

(other compositions etc.)

Except ultraviolet light absorber, do not hindering the scope of effect of the present invention, containing various adjuvant in oriented polyester films is also preferred mode.As adjuvant, such as, can enumerate: inorganic particle, thermotolerance polymeric particles, alkali metal compound, alkaline earth metal compound, phosphorus compound, antistatic agent, photostabilizer, fire retardant, thermal stabilizer, antioxidant, antigelling agent, surfactant etc.In addition, in order to play high transparent, also particle is not contained in fact in preferred polyester film." in fact not containing particle " refers to: when such as inorganic particle, is below 50ppm, preferably below 10ppm, the content being particularly preferably below detection limit when utilizing x-ray fluorescence analysis to carry out quantitative to inorganic elements.

(easy adhesive linkage)

In the present invention, in order to improve the cementability with polaroid, preferably have the easy adhesive linkage of at least a kind in vibrin, urethane resin or polyacrylics as principal ingredient at least one side of oriented polyester films.Wherein, " principal ingredient " refers in the solid constituent forming easy adhesive linkage to be the composition of more than 50 quality %.For the formation of the water-based coating fluid of at least a kind in the copolymer polyester resin of coating fluid preferably containing water-soluble or water dispersible of easy adhesive linkage, acrylic resin and urethane resin.As above-mentioned coating fluid, such as, can enumerate: water-soluble or water dispersible copolymer polyester resin solution, acrylic resin solution and polyurethane resin solution etc. disclosed in Jap.P. No. 3567927 publication, Jap.P. No. 3589232 publication, Jap.P. No. 3589233 publication, Jap.P. No. 3900191 publication, Jap.P. No. 4150982 publication etc.

Easy adhesive linkage can by by above-mentioned coating solution after the single or double of non-stretched film or longitudinal single axle drawn membrane, dry at 100 ~ 150 DEG C, transversely stretch further and obtain.The coating weight of final easy adhesive linkage preferably controls to be 0.05 ~ 0.2g/m ².If coating weight is lower than 0.05g/m ², then sometimes can be insufficient with the cementability of the polaroid obtained.On the other hand, if coating weight is more than 0.2g/m ², then resistance to blocking can reduce sometimes.When the two sides of mylar arranges easy adhesive linkage, the coating weight of the easy adhesive linkage on two sides can be the same or different, and can set in above-mentioned scope independently of one another.

In easy adhesive linkage, particle is added preferably in the easy slip of imparting.The mean grain size of preferred use particulate is the particle of less than 2 μm.If the mean grain size of particle is more than 2 μm, then particle easily comes off from coating.As the particle contained in easy adhesive linkage, such as, can enumerate: the inorganic particles such as titanium dioxide, barium sulphate, calcium carbonate, calcium sulphate, silicon dioxide, aluminium oxide, talcum, porcelain earth, clay, calcium phosphate, mica, hectorite, zirconia, tungsten oxide, lithium fluoride, calcium fluoride, phenylethylene, acrylic compounds, melamine class, benzocarbamidine amine, the organic polymer class particle etc. such as silicone based.These can be added in easy adhesive linkage individually, also can combine and add two or more.

Coating fluid can use known method to be coated with.Such as can enumerate: reverse roll rubbing method, gravure coating process, engagement rubbing method, roller brush method, spraying rubbing method, air knife coating method, line rod rubbing method, tubular type scraper (pipedoctor) method etc.These methods can be carried out alone or in combination.

The mensuration of the mean grain size of above-mentioned particle can be carried out by the following method.With scanning electron microscope (SEM), particle is taken pictures, be the multiplying power of 2 ~ 5mm with the size of minimum particle 1, measure the maximum gauge (distances between farthest 2) of 300 ~ 500 particles, using its mean value as mean grain size.

In order to make to become good with the cementability of polaroid, also corona treatment, coating process, flame treatment etc. can be implemented to mylar.

(functional layer)

Be on the face of opposite side in the face being configured at polaroid with mylar, in order to reflection-proof, suppress dazzle, suppress damage etc., and to arrange various functional layer, the i.e. functional layer of more than a kind be selected from the group that is made up of hard conating, antiglare layer, anti-reflection layer, low reflection layer, anti-low reflection layer, antireflection antiglare layer and antistatic layer on oriented polyester surface be also preferred mode.When arranging various functional layer, oriented polyester films preferably has easy adhesive linkage on its surface.Now, from the view point of suppressing the interference that produced by reflected light, near the geometrical mean preferably refractive index of easy adhesive linkage being adjusted to the refractive index of functional layer and the refractive index of oriented polyester films.The adjustment of the refractive index of easy adhesive linkage can adopt known method, such as can by easily adjusting containing titanium, zirconium, other metallicses in resin glue.

(manufacture method of oriented polyester films)

Oriented polyester films as diaphragm of the present invention can the manufacture method manufacture of conveniently mylar.Such as can enumerate following method: by vibrin melting, make extrusion molding be at the No yield point polyester of the sheet temperature more than glass transition temperature, after utilizing the velocity contrast of roller longitudinally to stretch, transversely stretched by stenter, implement thermal treatment.Can be that single axle drawn membrane also can for biaxially oriented film.

In order to make relative to film throughput direction be the direction of inclination 45 degree percent thermal shrinkage and be relative to film throughput direction-tilt 45 degree of directions percent thermal shrinkage difference absolute value reduce, preferably, in the single axle drawn membrane obtained by said method and the film making process of biaxially oriented film, after making thermal treatment, carry out the stress relaxation of the vergence direction produced in the operation cooled.Therefore, preferably, after heat treatment step, relaxation rate and temperature are adjusted to suitable scope, lax along thin-film width direction.Further preferably, the tension force of film throughput direction (direct of travel) is also adjusted to best scope.Preferably, the speed of tenter clip and the velocity contrast of pulling roll are adjusted to suitable scope, control the tension force of film throughput direction.In addition, further preferably, after heat treatment step, relaxation rate and temperature are adjusted to suitable scope, relax along thin-film width direction, reduce the grip separation of film throughput direction simultaneously, thus make it relax.In addition, be also preferably as follows method: cut off from tenter clip by film in refrigerating work procedure or decontrol, film being relaxed along film throughput direction and thin-film width direction, cools simultaneously.In addition, the disposable method involving in the row off-line annealing in process of such as 80 DEG C ~ 120 DEG C, 10 seconds ~ 90 minutes to batching also is effective.

For mylar, after having carried out longitudinal stretching, cross directional stretch, through heat treatment step, cut edge, both sides and make mill volume (millroll), carry out as required splitting thus segmentation volume (slitroll) can be obtained.Wherein, mill volume both ends 33% scope (from film right-hand member 33% region, from film left end 33% region), particularly the thermal shrinkage rate variance of vergence direction have the tendency uprised.Therefore, if when being such as off-line annealing in process, then preferred fully to guarantee the temperature of annealing in process, the mode of time regulates.

For the oriented polyester films with above-mentioned specific retardation and Nz coefficient, can be obtained by the condition (such as, the thickness etc. of stretching ratio, draft temperature, film) when regulating masking.Such as, stretching ratio is higher, and draft temperature is lower, and the thickness of film is thicker, more easily obtains high latency amount.On the other hand, stretching ratio is lower, and draft temperature is higher, and the thickness of film is thinner, more easily obtains low retardation.

As concrete film forming condition, such as, longitudinal drawing temperature and transverse drawing temperature are preferably 80 ~ 145 DEG C, are particularly preferably 90 ~ 140 DEG C.Longitudinal stretching multiplying power is preferably 1.0 ~ 3.5 times, is particularly preferably 1.0 times ~ 3.0 times.In addition, cross directional stretch multiplying power is preferably 2.5 ~ 6.0 times, is particularly preferably 3.0 ~ 5.5 times.

In order to retardation be controlled in above-mentioned specific scope, preferably control the ratio of longitudinal stretching multiplying power and cross directional stretch multiplying power.If the difference of stretching ratio is in length and breadth too small, be then difficult to improve retardation, thus not preferred.In addition, for raising retardation, it is also preferred for being set by draft temperature lower.The temperature of subsequent heat treatment is preferably 100 ~ 250 DEG C, is particularly preferably 180 ~ 245 DEG C.

In order to make Nz coefficient become above-mentioned specific value, preferably controlling the ratio of longitudinal stretching multiplying power and cross directional stretch multiplying power, most preferably making single axle drawn membrane.In addition, in order to reduce Nz coefficient, also preferably improving the molecular weight of polymkeric substance and adding copolymer composition to reduce crystallinity.Further, in order to the Nz coefficient of film is controlled in specific scope, can by setting total stretching ratio, draft temperature and carrying out aptly.Such as total stretching ratio is lower, and draft temperature is higher, more can obtain low Nz coefficient.

In order to make planar orientation degree become above-mentioned particular value, preferably control total stretching ratio.If total stretching ratio is higher, then planar orientation degree becomes too high, therefore not preferred.In addition, for reduction planar orientation degree, also preferred restrained stretching temperature.By increasing the difference of longitudinal stretching multiplying power and cross directional stretch multiplying power, setting low total stretching ratio, setting high draft temperature, Nz coefficient can be made, planar orientation degree becomes below particular value.

Because draft temperature and stretching ratio produce larger impact to the uneven thickness of film, therefore from the view point of uneven thickness, be also preferably filmed the optimization of condition.Particularly in order to improve retardation reduce longitudinal stretching multiplying power time, sometimes longitudinal thickness inequality be deteriorated.The region that can become non-constant in a certain specific scope existence of stretching ratio because longitudinal thickness is uneven, it is therefore desirable that divide into customised films condition in the situation departing from this scope.

Ultraviolet light absorber can combine known method to implement to the compounding of oriented polyester films.Such as, can wait compounding by the following method: use mixing extruder, the ultraviolet light absorber of drying is mixed with polymer raw material and makes masterbatch in advance, when forming thin film, this masterbatch of regulation be mixed with polymer raw material.

For the UVA agent concentration of above-mentioned masterbatch, in order to make ultraviolet light absorber dispersed and carry out compounding economically, be preferably set to the concentration of 5 ~ 30 quality %.As the condition preparing masterbatch, preferably use mixing extruder, extrusion temperature was extruded with 1 ~ 15 minute more than the fusing point of polyester raw material and at the temperature of less than 290 DEG C.Time more than 290 DEG C, the weightlessness of ultraviolet light absorber is large, and in addition, the viscosity of masterbatch reduces and increases.In extruding below 1 minute, the Homogeneous phase mixing of ultraviolet light absorber becomes difficulty.Now, also stabilizing agent, hue adjustment agent, antistatic agent can be added as required.

For compounding ultraviolet light absorber in the middle layer of the oriented polyester films of the above sandwich construction that haves three layers at tool, can be implemented by following gimmick.The stacked extruder of known melting is supplied separately with by the pellet of polyester as skin, as middle layer with the masterbatch containing ultraviolet light absorber is mixed in the ratio specified with the pellet of polyester, after drying, be supplied in the stacked extruder of known melting, be extruded into sheet from the die head of slit-shaped, casting roll make its cooling curing to make non-stretched film.Namely, use the extruder of more than 2, the manifold of 3 layers or interflow block (such as there is the interflow block of square merging part), the thin layer in the outer field thin layer of stacked formation two, formation middle layer, extrudes the sheet of 3 layers from tube head, make non-stretched film with casting roll cooling.

In order to remove foreign matter that cause optics bad point, that contain in the polyester of raw material, preferably in the manufacture process of oriented polyester films, carry out high-precision filtration when melt extruding.The filtering particle size (exhibits initial filtration efficiency 95%) of the filter material that the high-precision filtration of molten resin uses is preferably less than 15 μm.If the filtering particle size of filter material is more than 15 μm, then removes more than 20 μm foreign matters and easily become insufficient.

2. Polarizer

Forming of the both sides of the Polarizer of the present invention polaroid that to be the clamping of 2 polaroid protective films formed by the polyvinyl alcohol film etc. with iodine staining, the thermal shrinkage rate variance that at least one in aforementioned 2 polaroid protective films is preferably vergence direction is specific mylar.Polaroid and polaroid protective film are stacked via bonding agent, usually, carry out thermal treatment in 10 minutes ~ about 60 minutes to obtain Polarizer with the scope of 70 DEG C ~ 120 DEG C.

(configuration of polaroid protective film)

For liquid crystal indicator of the present invention, above-mentioned specific mylar preferably uses as two polaroid protective films of a pair Polarizer.A pair Polarizer refers to, relative to liquid crystal configurations in the Polarizer of incident light side with relative to the combination of liquid crystal configurations in the Polarizer of emergent light side.That is, this mylar is preferred for the Polarizer of the Polarizer of incident light side and both Polarizers of emergent light side.As long as this mylar uses as at least one formed in two polaroid protective films of each Polarizer.

In the embodiment be applicable to, this oriented polyester films can use as the polaroid protective film of the incident light side of the Polarizer of incident light side, and uses as the polaroid protective film of the emergent light side of the Polarizer of emergent light side.When the only one of 2 polaroid protective films forming Polarizer uses this oriented polyester films, another one can use arbitrary polaroid protective film (such as TAC film etc.).Adopt this oriented polyester films as be configured at incident light side Polarizer liquid crystal cell side polaroid protective film and be configured at the polaroid protective film of liquid crystal cell side of Polarizer of emergent light side time; change the possibility of polarized light property of liquid crystal cells; therefore, the polaroid protective film of these positions preferably uses the polaroid protective film except this oriented polyester films (such as with the film that TAC film, acrylic film, norborene system film are the such free of birefringence of representative).These films are the little person of preferred angled direction thermal shrinkage rate variance also.

3. liquid crystal indicator

In general, liquid crystal indicator has rear module, liquid crystal cells and front module successively towards the side (visible side or emergent light side) of display image from the side opposed with back light.In general rear module and front module are made up of transparency carrier, the nesa coating being formed at this liquid crystal cells side surface and the Polarizer that is configured at its opposite side.Herein, for Polarizer, in rear module, be configured at the side opposed with back light, in front module, be configured at the side (visible side or emergent light side) of display image.

Liquid crystal indicator of the present invention at least comprises back light, 2 Polarizers and the liquid crystal cells that is configured between 2 Polarizers as member of formation.Liquid crystal indicator of the present invention also suitably can have other member of formation, such as color filter, lens blooming, diffusion sheet, antireflection film etc. in addition to these.

The formation of backlight can be the sidelight mode using light guide plate, reflecting plate etc. as member of formation, can be also full run-down type mode.In the present invention, as the back light of liquid crystal indicator, preferably use the white light source with the luminescent spectrum of continuous print wide region.Herein, the luminescent spectrum of continuous print wide region refers to, the non-existent luminescent spectrum of wavelength of at least intensity vanishing of light in the region of the wavelength region may of 450nm ~ 650nm, preferably visible ray.As the white light source of luminescent spectrum with such continuous print wide region, such as, can enumerate White LED, but be not limited to this.

The White LED that can use in the present invention comprises: fluorophor mode, namely, by the light emitting diode sending blue light or ultraviolet light of compound semiconductor and fluorophor combination will be employed thus send the element of white; Organic Light Emitting Diode (Organiclightemittingdiode:OLED) etc.As fluorophor, such as, can enumerate: yttrium aluminum garnet system yellow fluorophor, terbium aluminium garnet system yellow fluorophor etc.In White LED, the white light-emitting diode comprising the light-emitting component blue LED and yttrium aluminum garnet system yellow fluorophor that employ compound semiconductor combined has continuously and the luminescent spectrum of wide region, and luminescence efficiency is also excellent, be therefore applicable as back light of the present invention.The power consumption of White LED is little, therefore utilizes its liquid crystal indicator of the present invention to be also conducive to energy-saving.

Possess as fluorescent tubes such as the widely used cold-cathode tube of back light, thermionic-cathode tubes luminescent spectrum to have peak discontinuous luminescent spectrum at specific wavelength all the time.Thus, be difficult to the effect obtaining expectation of the present invention, therefore not preferably as the light source of liquid crystal indicator of the present invention.

Embodiment

Below; with reference to embodiment, the present invention is more specifically described; but the present invention is by the restriction of following embodiment, also can in the scope of purport according to the invention in addition suitably change implement, these embodiments are all included in protection scope of the present invention.

The evaluation method of the physical property in embodiment as described below.

(1) the thermal shrinkage rate variance of vergence direction

Polaroid protective film 1 ~ 15 (carried out the polaroid protective film of off-line annealing in process and do not carried out the polaroid protective film of this process) described later is cut into respectively the square shape of 21cm, 23 DEG C, place more than 2 hours in the atmosphere of 65%RH.On the thin film, describe the circle of diameter 20cm, make its center be the center of film, longitudinally (packaging film feeding direction) 0 ° will be set to, and describe the straight line at the center by circle along 45 ° ,-45 ° directions, measure the diameter of all directions.This film is carried out in water the heating of 30 minutes with 85 DEG C, then wiping is attached to the moisture on surface, carries out air-dry, then 23 DEG C, place more than 2 hours in the atmosphere of 65%RH.Afterwards, the length of the straight line described along each diametric(al) is as described above measured.Then, compare the length of the diameter after the length of the diameter before thermal treatment and thermal treatment, obtain the percent thermal shrinkage in all directions, and then compare them, obtain the absolute value of the difference of percent thermal shrinkage.The Width this be determined at along film in same segmentation volume carries out 3 samplings, using it on average as thermal shrinkage rate variance.The result measured is as follows: for the polaroid protective film having carried out off-line annealing in process, and each 3 the middle thermal shrinkage rate variances in same segmentation volume are less than 0.4%, and the percent thermal shrinkage in 45 degree of directions and-45 degree directions is also less than 1.0%.

(2) light leak evaluation method

To fit in a face of the polaroid formed by PVA film triacetate cellulose film (FujifilmCorporation manufacture, thickness 80 μm), the mylar made by method described later of fitting on the other surface.Each film is via bonding agent and polarizing plate sticking.Afterwards, carry out the heating of 85 DEG C, 30 minutes in an oven, manufacture Polarizer.It should be noted that, paste in the orthogonal mode of main axis of orientation of the polarizing axis of polaroid and mylar.The mode so obtain 2 Polarizers being in the outside of 2 polaroids with mylar is configured at crossed nicols, uses the spectrophotometer V7100 that Japan Spectroscopy Corporation manufactures, and measures the maximum transmission rate under the wavelength of 550 ~ 600nm.

Zero: maximum transmission rate is less than 0.02%

×: maximum transmission rate is more than 0.02%

(3) retardation (Re)

Retardation refers to the parameter that the anisotropy (△ Nxy=|nx-ny|) of the refractive index with the orthogonal twin shaft on film defines with long-pending (the △ Nxy × d) of film thickness d (nm), is the isotropy of display optical and anisotropic yardstick.The anisotropy (△ Nxy) of the refractive index of twin shaft is obtained with following methods.Use molecular orientation meter (OjiScientificInstruments manufactures, MOA-6004 type molecular orientation meter) to obtain the axis of orientation direction of film, the mode becoming long limit with axis of orientation direction cuts out the rectangle of 4cm × 2cm, as test sample.For this sample, use Abbe refractomecer (ATAGOCO., LTD. manufacture, NAR-4T, mensuration wavelength 589nm) measure the refractive index (nx, ny) of orthogonal twin shaft and the refractive index (Nz) of thickness direction, using the anisotropy (△ Nxy) of the absolute value of the refringence of aforementioned twin shaft (| nx-ny|) as refractive index.The thickness d (nm) of film uses electric micrometer (FeinprufGmbH manufacture, Millitron1245D) to measure, and unit conversion is become nm.Retardation (Re) is obtained according to the anisotropy (△ Nxy) of refractive index and long-pending (the △ Nxy × d) of the thickness d (nm) of film.

(4) Nz coefficient

Will be by | ny-nz|/| the value that ny-nx| obtains is as Nz coefficient.Wherein, with the value of way selection ny and nx of ny>nx.

(5) planar orientation degree (△ P)

The value that will be obtained by (nx+ny)/2-nz is as planar orientation degree (△ P).

(6) thickness direction retardation amount (Rth)

Thickness direction retardation amount refers to and 2 birefringence △ Nxz (=| nx-nz|), the △ Nyz (=| ny-nz|) when observing from film thickness directional profile is multiplied by film thickness d and the parameter of the mean value of the display delay amount obtained respectively.Utilize the method same with the mensuration of retardation to obtain nx, ny, nz and film thickness d (nm), calculate (△ Nxz × d) and obtain thickness direction retardation amount (Rth) with the mean value of (△ Nyz × d).

(7) rainbow spot is observed

At the mylar that the one-sided attaching of the polaroid formed by PVA and iodine makes by aftermentioned method, make the polarizing axis of polaroid become vertical with the orientation main shaft of mylar, the one side in its opposition side attaches TAC film (Fuji Photo Film Co., Ltd.'s manufacture, thickness 80 μm) and makes Polarizer.The Polarizer obtained is clipped liquid crystal respectively at each 1 of both sides, at each Polarizer be crossed nicols condition under be configured, thus make liquid crystal indicator.Each Polarizer is to be configured previous polyesters film in the mode with liquid crystal opposite side (comparatively distant positions).The light source of liquid crystal indicator uses White LED as light source (day sub-chemical, NSPW500CS), and described White LED combines by blue LED and yttrium aluminum garnet class yellow fluorophor the light-emitting component obtained and forms.From the front of this liquid crystal indicator and obliquely carry out visualization, produce for or without rainbow spot, judge as follows.

A: all produce without rainbow spot from either direction.

A ': when from oblique observation, according to angle views to extremely light rainbow spot.

B: when from oblique observation, according to angle views to light rainbow spot.

C: when from oblique observation, can be observed rainbow spot.

D: when from frontal and oblique observation, can be observed rainbow spot.

(8) tear strength

Use the Elmendorf tear tester (Elmendorftearingtester) manufactured by Toyo Seiki making, according to JISP-8116, measure the tear strength of each film.Tear direction to carry out in the mode that the orientation major axes orientation with film is parallel, judge as follows.It should be noted that, the mensuration molecular orientation meter (OjiScientificInstruments manufacture, MOA-6004 type molecular orientation meter) of orientation major axes orientation measures.

Zero: tear strength is more than 50mN

×: tear strength is lower than 50mN

(Production Example 1-polyester A)

Intensification reaction kettle of the esterification, when reaching 200 DEG C, drop into terephthalic acid (TPA) 86.4 mass parts and ethylene glycol 64.6 mass parts, drop into antimony trioxide 0.017 mass parts, magnesium acetate tetrahydrate 0.064 mass parts, triethylamine 0.16 mass parts as catalyzer while stirring.Then, carry out pressurization and heat up, carry out pressurization esterification under gauge pressure 0.34MPa, the condition of 240 DEG C after, reaction kettle of the esterification is returned to normal pressure, interpolation phosphoric acid 0.014 mass parts.And then, be warming up to 260 DEG C with 15 minutes, add trimethyl phosphate 0.012 mass parts.Then, over the course of 15 mins, carry out dispersion treatment with high pressure dispersing machine, after 15 minutes, the esterification reaction product obtained be transferred to batch condensation polymerization reactor, 280 DEG C, decompression under carry out polycondensation reaction.

After polycondensation reaction terminates, retaining diameter with 95% is that the stainless steel fibre filtrator of 5 μm carries out filtration treatment, be extruded into strand form from nozzle, use the chilled water having carried out filtration treatment (aperture: less than 1 μm) in advance to carry out cooling, solidifying, be cut into partical.The limiting viscosity of the pet resin (A) (hereinafter referred to as PET (A)) obtained is 0.62dl/g, in fact not containing non-active particles and inner precipitate particle.

(Production Example 2-polyester B)

By the ultraviolet light absorber (2 of 10 mass parts dryings, 2 '-(1,4-phenylene) two (4H-3,1-benzoxazine-4-ketone), 90 mass parts do not mix containing the PET (A) (limiting viscosity is 0.62dl/g) of particle, use mixing extruder, obtain the pet resin (B) (hereinafter referred to as PET (B)) containing ultraviolet light absorber.

(preparation of Production Example 3-cementability modification coating fluid)

Utilize usual way to carry out ester exchange reaction and polycondensation reaction, (overall relative to dicarboxylic acid component) prepared as dicarboxylic acid component be terephthalic acid (TPA) 46 % by mole, m-phthalic acid 46 % by mole and 5-sodium sulfo isophthalate 8 % by mole, as the water dispersible of (overall relative to glycol component) of the glycol component composition that is ethylene glycol 50 % by mole and neopentyl glycol 50 % by mole containing the copolymer polyester resin of Sulfonic acid metal alkali.Then, after water 51.4 mass parts, isopropyl alcohol 38 mass parts, normal-butyl cellosolve 5 mass parts, the mixing of nonionic class surfactant 0.06 mass parts, add thermal agitation, copolymer polyester resin 5 mass parts of above-mentioned water dispersible containing Sulfonic acid metal alkali is added after reaching 77 DEG C, continue to stir until after there is no the caking of resin, the liquid that fallen apart by aqueous resin is cooled to normal temperature, obtains the uniform water dispersible copolymer polyester resin liquid of solid component concentration 5.0 quality %.And then, condensed matter silica dioxide granule (FujiSilysiachemicalLtd. manufacture, Sylysia310) 3 mass parts are distributed to after in 50 mass parts water, aqueous dispersions 0.54 mass parts of Sylysia310 is added in 99.46 mass parts above-mentioned water dispersible copolymer polyester resin liquid, add water 20 mass parts while stirring, thus obtain cementability modification coating fluid.

(polaroid protective film 1)

As base film middle layer raw material by not containing particle PET (A) resin granular material 90 mass parts with containing PET (B) resin granular material 10 mass parts of ultraviolet light absorber drying under reduced pressure (1Torr) after 6 hours at 135 DEG C, be supplied to extruder 2 (middle layer II layer is used), in addition, after PET (A) is utilized usual way drying, be supplied to extruder 1 (outer I layer and outer III use) respectively, and dissolve at 285 DEG C.The filter material of stainless steel sintered body (nominal filter fineness 10 μm of particles 95% retain) is used by these 2 kinds of polymkeric substance to filter respectively, stacked in 2 kind of 3 laminated stream block, after being extruded into sheet by tube head, use electrostatic applying casting method to be wound on the upper cooling curing of casting drum of surface temperature 30 DEG C, make non-stretched film.Now, adjust the discharge rate of each extruder, make the ratio of the thickness of I layer, II layer, III layer be 10:80:10.

Then, by reverse roll method at the two sided coatings of this PET film that do not stretch above-mentioned cementability modification coating fluid, dried coating weight is made to become 0.08g/m ², then at 80 DEG C dry 20 seconds.

The non-stretched film being formed with this coating layer is guided to tentering drawing machine, clamps the end of film with fixture, while guide to the hot blast district of temperature 125 DEG C, stretch 4.0 times in the width direction.Then, under the state keeping the width stretched in the width direction, process with temperature 225 DEG C, 30 seconds, cut removing edge, both sides, thus the mill obtaining being formed by the uniaxial orientation PET film of film thickness about 50 μm is rolled up.This mill is rolled up 3 deciles, obtains 3 segmentations volume (L, C, R).For each segmentation volume, the segmentation volume making the off-line annealing in process of having carried out 90 DEG C, 5 minutes, the segmentation not carrying out off-line annealing in process roll up these 2 kinds.

(polaroid protective film 2)

By changing the thickness of non-stretched film, make thickness be about 100 μm, in addition, the segmentation obtaining being formed by uniaxial orientation PET film in the same manner as polaroid protective film 1 is rolled up.Make the segmentation that the segmentation having carried out off-line annealing in process rolled up, do not carry out off-line annealing in process and roll up these 2 kinds in the same manner as polaroid protective film 1.

(polaroid protective film 3)

Use the roller group through heating and infrared heater that the non-stretched film made by the method same with polaroid protective film 1 is heated to 105 DEG C; then stretch after 1.5 times by the roller group with difference along direct of travel; stretch 4.0 times in the width direction according to the method same with polaroid protective film 1, obtain the segmentation volume formed by the Biaxially oriented PET film of film thickness about 50 μm.Make the segmentation that the segmentation having carried out off-line annealing in process rolled up, do not carry out off-line annealing in process and roll up these 2 kinds in the same manner as polaroid protective film 1.

(polaroid protective film 4)

According to the method same with polaroid protective film 3, along direct of travel stretch 2.0 times, stretch 4.0 times in the width direction, obtain the segmentation that formed by the Biaxially oriented PET film of film thickness about 50 μm and roll up.Make the segmentation that the segmentation having carried out off-line annealing in process rolled up, do not carry out off-line annealing in process and roll up these 2 kinds in the same manner as polaroid protective film 1.

(polaroid protective film 5)

According to the method same with polaroid protective film 1, do not use the PET resin (B) containing ultraviolet light absorber in middle layer, obtain the segmentation volume formed by the uniaxial orientation PET film of film thickness 50 μm.Make the segmentation that the segmentation having carried out off-line annealing in process rolled up, do not carry out off-line annealing in process and roll up these 2 kinds in the same manner as polaroid protective film 1.

(polaroid protective film 6)

According to the method same with polaroid protective film 1, along direct of travel stretch 1.0 times, stretch 3.5 times in the width direction, obtain the segmentation that formed by the uniaxial orientation PET film of film thickness about 75 μm and roll up.Make the segmentation that the segmentation having carried out off-line annealing in process rolled up, do not carry out off-line annealing in process and roll up these 2 kinds in the same manner as polaroid protective film 1.

(polaroid protective film 7)

Utilize the method same with polaroid protective film 1, change the thickness of non-stretched film, cross directional stretch multiplying power is set to 3.8 times, draft temperature is set to 135 DEG C, the segmentation obtaining being formed by the uniaxial orientation PET film of thickness about 100 μm is rolled up.Make the segmentation that the segmentation having carried out off-line annealing in process rolled up, do not carry out off-line annealing in process and roll up these 2 kinds in the same manner as polaroid protective film 1.

(polaroid protective film 8)

Utilize the method same with polaroid protective film 1, cross directional stretch multiplying power is set to 3.8 times, draft temperature is set to 135 DEG C, obtain the segmentation volume formed by the uniaxial orientation PET film of thickness about 50 μm.Make the segmentation that the segmentation having carried out off-line annealing in process rolled up, do not carry out off-line annealing in process and roll up these 2 kinds in the same manner as polaroid protective film 1.

(polaroid protective film 9)

Utilize the method same with polaroid protective film 1, cross directional stretch multiplying power is set to 3.8 times, obtain the segmentation volume formed by the uniaxial orientation PET film of thickness 50 μm.Make the segmentation that the segmentation having carried out off-line annealing in process rolled up, do not carry out off-line annealing in process and roll up these 2 kinds in the same manner as polaroid protective film 1.

(polaroid protective film 10)

Utilize the method same with polaroid protective film 1, cross directional stretch multiplying power is set to 4.2 times, draft temperature is set to 135 DEG C, obtain the segmentation volume formed by the uniaxial orientation PET film of thickness about 50 μm.Make the segmentation that the segmentation having carried out off-line annealing in process rolled up, do not carry out off-line annealing in process and roll up these 2 kinds in the same manner as polaroid protective film 1.

(polaroid protective film 11)

Utilize the method same with polaroid protective film 1, change the thickness of non-stretched film, cross directional stretch multiplying power is changed into 3.8 times, thus the segmentation obtaining being formed by the uniaxial orientation PET film of thickness 38 μm is rolled up.Make the segmentation that the segmentation having carried out off-line annealing in process rolled up, do not carry out off-line annealing in process and roll up these 2 kinds in the same manner as polaroid protective film 1.

(polaroid protective film 12)

Utilize the method same with polaroid protective film 1, change the thickness of non-stretched film, thus the segmentation obtaining being formed by the uniaxial orientation PET film of thickness 38 μm is rolled up.Make the segmentation that the segmentation having carried out off-line annealing in process rolled up, do not carry out off-line annealing in process and roll up these 2 kinds in the same manner as polaroid protective film 1.

(polaroid protective film 13)

Utilize the method same with polaroid protective film 3, along direct of travel stretch 1.8 times, stretch 2.0 times in the width direction, obtain the segmentation that formed by the Biaxially oriented PET film of film thickness about 275 μm and roll up.Make the segmentation that the segmentation having carried out off-line annealing in process rolled up, do not carry out off-line annealing in process and roll up these 2 kinds in the same manner as polaroid protective film 1.

(polaroid protective film 14)

Utilize the method same with polaroid protective film 3, along direct of travel stretch 3.6 times, stretch 4.0 times in the width direction, obtain the segmentation that formed by the Biaxially oriented PET film of film thickness about 38 μm and roll up.Make the segmentation that the segmentation having carried out off-line annealing in process rolled up, do not carry out off-line annealing in process and roll up these 2 kinds in the same manner as polaroid protective film 1.

(polaroid protective film 15)

Utilize the method same with polaroid protective film 1, change the thickness of non-stretched film, thus the segmentation obtaining being formed by the uniaxial orientation PET film of thickness about 10 μm is rolled up.Make the segmentation that the segmentation having carried out off-line annealing in process rolled up, do not carry out off-line annealing in process and roll up these 2 kinds in the same manner as polaroid protective film 1.

For polaroid protective film 1 ~ 15, the result of light leak evaluation is shown in table 1 (utilize off-line anneal the sample processed), table 2 (do not utilize off-line anneal the sample carrying out processing).In table 1 and 2, L position refers to left end, and C position refers to central authorities, and R position refers to right-hand member.

In addition, use polaroid protective film 1 ~ 15 (utilize off-line anneal sample process), the result for the liquid crystal indicator mensuration rainbow spot observation made as described above and tear strength is shown in following table 3.

[table 1]

[table 2]

[table 3]

In table 3, polaroid protective film No.7* represents and uses polaroid protective film 7 as polaroid protective film, uses Organic Light Emitting Diode (OLED) as the situation of light source.In addition, in table 3, polaroid protective film No.7** represents and uses polaroid protective film 7 as polaroid protective film, uses cold-cathode tube as the situation of light source.

According to the result shown in table 3, the retardation of display orientation mylar is more than 4000, and when its Nz coefficient is less than 1.7, rainbow spot can be suppressed significantly to produce.In addition, demonstrating on the basis of this condition, by controlling below 0.13 by the planar orientation degree of oriented polyester films, can more effectively suppress rainbow spot to produce.

utilizability in industry

According to the present invention, can provide the polaroid protective film formed by mylar, it is when being configured at 2 Polarizers under crossed nicols environment, and the generation of a small amount of light leak is inhibited and is suitable for obtaining having the liquid crystal indicator of superior visibility.Thus, the utilizability in industry of the present invention is high.

Claims

1. the polaroid protective film formed by mylar; it is characterized in that, being the percent thermal shrinkage in 45 degree of directions relative to film throughput direction and be the absolute values of difference of percent thermal shrinkage in-45 degree directions relative to film throughput direction being less than 0.4% of described polaroid protective film.

2. polaroid protective film according to claim 1, wherein, the retardation of mylar is 4000 ~ 30000nm, Nz coefficient is less than 1.7.

3. polaroid protective film according to claim 1 and 2, wherein, the planar orientation degree of mylar is less than 0.13.

4. a Polarizer, its both sides being included in polaroid are laminated with the formation of polaroid protective film,

The polaroid protective film of at least one-sided polaroid protective film according to any one of claims 1 to 3.

5. a Polarizer, its both sides being included in polaroid are laminated with the formation of polaroid protective film,

A polaroid protective film is formed by triacetate cellulose film,

The polaroid protective film of another polaroid protective film according to any one of claims 1 to 3.

6. a liquid crystal indicator, its liquid crystal cells that there are back light, 2 Polarizers and be configured between described 2 Polarizers,

Described back light is the white light source with continuous luminous spectrum,

Described Polarizer is the formation being laminated with polaroid protective film in the both sides of polaroid,

The polaroid protective film of at least one according to any one of claims 1 to 3 of the polaroid protective film of at least one being configured at the polaroid protective film of the Polarizer of incident light side and the Polarizer being configured at emergent light side.

7. liquid crystal indicator according to claim 6; wherein, the polaroid protective film of polaroid protective film according to any one of claims 1 to 3 of the emergent light side of the polaroid protective film being configured at the incident light side of the Polarizer of described incident light side and the Polarizer being configured at described emergent light side.