CN105073386B

CN105073386B - Polyester film and its manufacture method

Info

Publication number: CN105073386B
Application number: CN201480017885.4A
Authority: CN
Inventors: 中居真; 中居真一; 浜田范; 浜田一范; 井上正央
Original assignee: Fujifilm Corp
Current assignee: Fujifilm Corp
Priority date: 2013-03-28
Filing date: 2014-03-24
Publication date: 2017-03-08
Anticipated expiration: 2034-03-24
Also published as: TW201446473A; JP2014189002A; KR20150119438A; KR101591237B1; WO2014157108A1; JP6016688B2; CN105073386A; TWI592284B

Abstract

The present invention provides polyester film and its manufacture method, the thickness of described polyester film is less than 100 μm, in the maximum Y [%/m of the rate of change y absolute value of the per unit distance of the maximum X [%/m] and above-mentioned x of percent thermal shrinkage variable quantity x [%/m] absolute value in the direction vertical with above-mentioned film width of film width, above-mentioned film width per unit distance²] meet following formula (I) and (II):0.01 ＜ X ＜ 2.00 ... (I) 0.1 ＜ Y ＜ 20.0 ... (II).

Description

Polyester film and its manufacture method

Technical field

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

Background technology

Polyester is applied to be electrically insulated in the various uses such as purposes, optical applications.Wherein, as electric insulation purposes, in recent years Carry out the solaode purposes such as the back-protective piece (so-called backboard) of particularly solaode to attract attention.

Carry out coating or the paste functionality material on film sometimes of polyester film obtained from biaxial stretch-formed grade after melt extruding Expect and make functional membrane to utilize.Now, if manufacturing relatively thin polyester film when carrying out conveyance with roller etc., sometimes in heating Produce gauffer, scratch etc. in polyester film because of a variety of causes during conveyance.

As the technology related to above-mentioned situation, disclose the aspect from size stabilization, polyester film is arranged Duplexer containing metal or the floor of metal system oxide (for example, referring to Japanese Unexamined Patent Publication 2010-052416 publication).

Additionally, for the change in size of the film in heat treatment step when processing after suppressing, disclosing to define and gather to benzene The film of the percent thermal shrinkage of naphthalate film and its uniformity, refractive index, elongation at break etc. and its manufacture method (example As with reference to Japanese Unexamined Patent Publication 2009-149066 publication).

Content of the invention

Invent problem to be solved

According to Japanese Unexamined Patent Publication 2010-052416 publication and Japanese Unexamined Patent Publication 2009-149066 publication although showing poly- The low thermal shrinkage of ester film and its homogenization contribute to improveing gauffer of polyester film etc., but gauffer suppresses and insufficient.Particularly The relatively thin polyester film that the thickness of polyester film is reached less than 100 μm cannot be suppressed to carry out heating the conveyance easily producing during conveyance Direction (MD；Longitudinally, Machine Direction) wrinkle (hereinafter also referred to as " tendon shape protuberance ").In recent years, from make use of The lightweight of the product of film, saving of raw material etc. are set out, and the relatively thinning of film constantly develops, so the gauffer suppression of relatively thin polyester film System is important problem.

Even if that the present invention is in view of the foregoing and carries out reaching less than 100 μm relatively it is therefore an objective to provide by thickness Thin polyester film carries out polyester film and its manufacture method being also difficult to when heating conveyance produce gauffer in conveyance direction, and problem is Reach this purpose.

For solving the scheme of problem

The tendon shape protuberance that the present invention obtains relatively thin polyester film can be by reducing the MD thermal contraction of the polyester film before heating The change of the local of rate and the opinion that eliminates, and reached based on described opinion.

Specific scheme for reaching above-mentioned problem is as follows.

<1>A kind of polyester film, its thickness be less than 100 μm, the film width per unit distance of film width with The per unit of the maximum X [%/m] and x of percent thermal shrinkage variable quantity x [%/m] absolute value in the vertical direction of film width away from From rate of change y absolute value maximum Y [%/m²] meet following formula (I) and (II).

0.01 ＜ X ＜ 2.00 ... (I)

0.1 ＜ Y ＜ 20.0 ... (II)

<2>According to<1>Described polyester film is wherein, vertical with film width in the central part of film width The percent thermal shrinkage in direction is more than 0.01% and less than 3%.

<3>According to<1>Or<2>Described polyester film, wherein, the direction vertical with film width of film width Percent thermal shrinkage deviation is more than 0.01% and less than 0.5%.

<4>According to<1>~<3>Any one of polyester film, wherein, film width by means of differential scanning calorimetry The pre- peak temperature deviation that mensure (DSC) measures is more than 0.5 DEG C and less than 10 DEG C.

<5>According to<1>~<4>Any one of polyester film, wherein, the intrinsic viscosity of polyester film be 0.55dL/g with Go up and below 0.90dL/g.

<6>According to<1>~<5>Any one of polyester film, wherein, the amount of the terminal carboxyl group of polyester film is 5eq/ ton Above and below 35eq/ ton.

<7>According to<1>~<6>Any one of polyester film, wherein, polyfunctional monomer more than 3 senses The containing ratio of Component units is rubbed for 0.005 mole of more than % and 2.5 with respect to whole Component units of the polyester in polyester film You are below %.

<8>A kind of manufacture method of polyester film, it includes following operation：Polyester feed stock resin is carried out melting with lamellar squeeze Go out, the film forming process cooling down and polyester film being shaped on curtain coating drum；

Polyester film formed thereby is carried out along its length the longitudinal stretching operation of longitudinal stretching；

Polyester film is transported successively to following portion, by the polyester film after longitudinal stretching along the width vertical with length direction Direction carries out the cross directional stretch operation of cross directional stretch, and wherein said each portion is：Polyester film after longitudinal stretching is preheated to can The preheating part of temperature of stretching, the width vertical with length direction to preheated polyester film edge apply tension force and carry out horizontal stroke To stretching extension section, the polyester film carrying out after longitudinal stretching and cross directional stretch carried out heat and makes its crystallization and thermal finalization Thermal finalization portion, the polyester film through thermal finalization is heated the overstrain that the tension recovery of polyester film is removed striping heat pine Relaxation portion and the cooling end by the polyester film cooling after hot wire-CVD,

In at least one of thermal finalization portion and hot wire-CVD portion, heater is utilized to the end of the polyester film of width Carry out selective radiation heating, and, in cooling end, the surface temperature of polyester film will be made when being cooled to 70 DEG C for 150 DEG C Average cooling rate in film width end is set to 1.01 times of the average cooling rate in the central part of film width ～2 times.

<9>According to<8>The manufacture method of described polyester film, wherein, radiant heating is carried out using ceramic heater.

<10>According to<8>Or<9>The manufacture method of described polyester film, wherein, polyester film in cross directional stretch operation Width reach the width L1 of polyester film during maximum with polyester film the polyester film from the end of the cooling end that cooling end leaves Width L2 meets following formula (1), and,

Conveyance speed S2 of the polyester film in conveyance speed S1 of the polyester film in preheating part and the end of cooling end meets Following formula (2).

[mathematical expression 1]

<11>According to<8>~<10>Any one of polyester film manufacture method, wherein, cross directional stretch operation use The biaxial stretch-formed device of described below, this biaxial stretch-formed device possesses preheating part, extension section, thermal finalization portion, hot wire-CVD portion and cold But portion, and an end is held to the two ends of the width of polyester film in preheating part using at least two holding components Portion, thus polyester film is transported to cooling end from preheating part,

By with preheating part in holding polyester film width an end holding component be adjacent to this The interval holding the holding component of component is compared, the holding of the end of width of holding polyester film in constriction cooling end Component and the interval holding component being adjacent to this holding component, thus reduce the conveyance speed of polyester film.

<12>According to<8>~<11>Any one of polyester film manufacture method, wherein,

In cooling end, it is set to 2 by making the surface temperature of polyester film average cooling rate when being cooled to 70 DEG C for 150 DEG C DEG C/sec～100 DEG C/sec of scope.

Invention effect

Even if removing in accordance with the invention it is possible to providing and carrying out heating in the relatively thin polyester film that thickness is reached less than 100 μm Also it is difficult to when sending polyester film and its manufacture method of gauffer is produced on conveyance direction.

Brief description

Fig. 1 is the schematic diagram of the problem for the present invention is described.

Fig. 2 is the schematic diagram for the formula of the present invention (I) and (II) are described.

Fig. 3 be from upper surface represent biaxial stretcher an example upper surface figure.

Fig. 4 is the schematic diagram representing the method for mensure MD percent thermal shrinkage in embodiment.

Specific embodiment

The thickness of the polyester film of the present invention is less than 100 μm, the film width per unit distance on film width The per unit of the maximum X [%/m] and x of percent thermal shrinkage variable quantity x [%/m] absolute value in the direction vertical with film width Maximum Y [the %/m of the rate of change y absolute value of distance²] meet following formula (I) and (II).

0.01 ＜ X ＜ 2.00 ... (I)

0.1 ＜ Y ＜ 20.0 ... (II)

The film that thickness is less than 100 μm is also referred to as relatively thin film.

The manufacture method of polyester film describes in detail below, relatively thin film generally carry out transporting and stretching by using roller etc. and Obtain.Now, the conveyance direction of film is also referred to as MD (Machine Direction) direction.Additionally, the MD direction of film is also referred to as The length direction of film.Additionally, film width is the direction vertical with length direction.Film is transported by film width on side In the film that side manufactures, also referred to as TD (laterally, Transverse Direction) direction.

In the present invention, by film width be referred to as TD or TD direction, by the direction vertical with film width be referred to as MD or MD direction.Additionally, the thermal contraction in MD direction is also referred to as MD thermal contraction, its ratio is referred to as MD percent thermal shrinkage.Therefore, with film width The percent thermal shrinkage in the vertical direction in degree direction is also expressed as MD percent thermal shrinkage.

Additionally, the species of polyester is not particularly limited, the species of the polyester that can suitably use in the present invention is chatted later State, particularly commonly used polyethylene terephthalate (Polyethylene terephthalate；PET).Hereinafter, claim During for PET, refer to polyethylene terephthalate.

Polyester film carries out multifunction or compound by the stacking of multiple polyester films or in polyester film upper strata azido functional layer sometimes Change.In the processing of such polyester film, usual lateral dominance is transported with roller etc., while carrying out the heating of film, stretching etc..

If relatively thin polyester film is heated conveyance, there is polyester film in the MD direction and tighten (drawing I つれ), produce The tendency of raw gauffer.By the concavo-convex referred to as tendon shape protuberance of the wrinkle on film in the present invention, the wrinkle on described film is that film exists Cool down in the state of producing wrinkle, solidify and remain on film.If polyester film has tendon shape protuberance, coating coating on film Become during liquid to be difficult to equably be coated.If additionally, pasting the functional layers such as laminate layers on having crisp film, easily producing The raw fault such as entrance bubble between film and functional layer.

Relatively thin plastic foil for example there is as tape all the time, but, typically, make using with organic solvent in the past For the coating fluid of solvent, solvent is made to distribute required temperature low (for example, less than 100 DEG C).But, in recent years, Environment Oriented is protected Shield and become to tend to using water solvent (solvent comprising water), sometimes for so that water solvent is distributed and at 150 DEG C about High temperature under heated.Additionally, sometimes the material being solidified by heating as hard coat agent is laminated on film or film Containing hard coat agent, now, film is typically heated to 170 DEG C～180 DEG C.

Therefore, it is more prone to wrinkle in film, compared with the past, the generation of tendon shape protuberance easily becomes notable.

Generation to tendon shape protuberance has made intensive studies, and result thinks, tendon shape protuberance is by because film is because of heating The tension force when thermal contraction producing and film conveyance, film deforms with corrugated, and its immobilization and produce.Known by suppression Tension force etc. during masking conveyance is suppressing wrinkle, but only such and insufficient.

Investigate the main position producing of tendon shape protuberance in polyester film, result is known, in width (TD) per unit In distance, the change of the partly big position of the change of MD percent thermal shrinkage and MD percent thermal shrinkage position drastically is concentrated and is produced.

On width, the change of the big position of the change of MD percent thermal shrinkage and MD percent thermal shrinkage position drastically is in film During heating, local real estate is raw shrinks inequality, and the length easily producing local is uneven.If thinking to the length inequality producing local The local tension force applying film conveyance, then produce the inequality of stress, produce this position (producing the uneven place of the length of local) The position that stress is partly concentrated.Think that the position partly concentrated in this stress easily produces tendon shape protuberance.

On the other hand, by make the every TD unit distance on the TD direction of polyester film MD percent thermal shrinkage variable quantity x [%/ M] absolute value the rate of change y absolute value of the per unit distance of maximum X [%/m] and x maximum Y [%/m²] meet following Formula (I) and (II), can suppress the tendon shape of polyester film to swell.

0.01 ＜ X ＜ 2.00 ... (I)

0.1 ＜ Y ＜ 20.0 ... (II)

For the relation of above-mentioned (I) and (II) and tendon shape protuberance suppression, illustrated using Fig. 1 and Fig. 2.

Fig. 1 is the schematic diagram of the problem for the present invention is described, Fig. 2 is for the formula of the present invention (I) and (II) are described Schematic diagram.

In Fig. 1, overlap is shown in the schematic diagram of polyester film and the table that produce tendon shape protuberance by TD end along MD direction of film Show the curve (D of the MD shrinkage factor distribution in TD direction at the position of the film in TD direction of this polyester film_Sh).Curve (D_Sh) with song Axle (position of the film in TD direction) on the downside of line and the axle (MD percent thermal shrinkage) on the right side of curve are as reference axis.

The tendon shape protuberance easily being produced by carrying out to relatively thin polyester film heating conveyance easily results from polyester film TD direction by end, represented with gushet in Fig. 1.For the polyester film creating tendon shape protuberance, if measuring along TD direction MD percent thermal shrinkage, then in the position MD percent thermal shrinkage substantially constant not producing tendon shape protuberance, but producing the area of tendon shape protuberance Domain is sharp changed in (region of the dotted line being represented with R), in the region not having tendon shape protuberance, there is MD percent thermal shrinkage The tendency that diminishes of variable quantity.

In Fig. 2, the TD direction along polyester film illustrates the position (P) of P1～P6 with (for example, 0.05m interval) at equal intervals.If MD percent thermal shrinkage at P1 is Sh1, if the MD percent thermal shrinkage at P2 is Sh2, until P6, the MD at mensure each position (P) place is warm to be received Shrinkage (Sh).

With regard to the position of n (n is more than 1), adjoining position will be deducted by the MD percent thermal shrinkage (Shn) of position (Pn) (Pn+1) the MD percent thermal shrinkage (Shn+1) at place, so by this value divided by Pn and Pn+1 between distance obtained from amount be set to MD heat The variable quantity xn of shrinkage factor.It is " the per unit distance of the film width of film width vertical with film width Percent thermal shrinkage variable quantity x [%/m] in direction ".In n xn, maximum value is " the maximum X of variable quantity x ".

For example, the MD percent thermal shrinkage (Sh2) at the MD percent thermal shrinkage (Sh1) at the P1 of position and position P2 is deducted and divided by P1 and P2 apart from when the amount that obtains calculate as x1.Similarly, calculate the x2～x5 shown in Fig. 2.Wherein, for example, x4 is (the x4=x during variable quantity of maximum_max), x4 is maximum X (x4=X).

Additionally, " rate of change y of the per unit distance of x " passes through to be deducted by the MD percent thermal shrinkage (Shn) of position (Pn) The MD percent thermal shrinkage (Shn+1) at adjoining position (Pn+1) place so by this value divided by Pn and Pn+1 between distance obtained from measure The xn and MD percent thermal shrinkage (Shn+ being deducted adjoining position (Pn+2) place by the MD percent thermal shrinkage (Shn+1) of position (Pn+1) 2) so by this value divided by Pn and Pn+1 between distance obtained from measure xn+1 difference, the intermediate point divided by Pn and Pn+1 and Pn+1 Obtain with the distance of the intermediate point of Pn+2.In the y of n-1 being calculated, maximum rate of change is the maximum Y of rate of change y.

For example, in Fig. 2, by by the difference of x1 and x2 divided by the intermediate point of P1 and P2 and the distance of the intermediate point of P2 and P3 Calculate y1, by the difference of x2 and x3 is calculated y2 divided by intermediate point and the distance of the intermediate point of P3 and P4 of P2 and P3.Respectively In y1～y4 obtained from calculating, y4 is (y4=y during maximum rate of change_max), y4 is maximum Y (y4=Y).

In Fig. 1, as described as the region that sharp changes of MD percent thermal shrinkage illustrate as R.By institute in Fig. 2 The variable quantity x that the method shown calculates is the MD shrinkage factor distribution curve (D in the region R shown in Fig. 1_Sh) tangent line Q slope, The maximum of the slope of tangent line Q on TD direction is maximum X.Additionally, the rate of change y being calculated by the method shown in Fig. 2 MD shrinkage factor distribution curve (D in region R shown in Fig. 1_Sh) slope rate of change, the maximum of the rate of change in TD direction It is worth for maximum Y.

0.01 ＜ X ＜ 2.00 (formula (I)) is met by making X and Y so obtaining in the present invention, and, 0.1 ＜ Y ＜ 20.0 (formula (II)), thus the change of the local of MD percent thermal shrinkage of the reason suppress the tendon shape becoming polyester film to swell.Pass through Reduce X and Y, the variable quantity of MD percent thermal shrinkage diminishes, easily become uniform as the overall percent thermal shrinkage of polyester film.But, though So mechanism is not known, even if percent thermal shrinkage deviation diminishes also easily produces tendon shape protuberance, X and Y all specifies lower limit.

Hereinafter, the polyester film and its manufacture method of the present invention is described in detail.

In addition, in the present invention, heating conveyance refer to the film surface temperature of the film in the conveyance of polyester film be heated to 130 DEG C with On, the present invention can also be suitable for when the film surface temperature of film reaches the heating conveyance of more than at higher temperature 200 DEG C.

(formula (I) and (II))

In the present invention, the MD percent thermal shrinkage variable quantity x of the every TD unit distance on the width (TD) of polyester film [%/ M] absolute value maximum X [%/m] meet 0.01 ＜ X ＜ 2.00 (formula (I)).

If X is less than 0.01, although mechanism is unclear, film becomes easily to produce tendon shape protuberance on the whole.If X is 2 More than, then the position partly concentrated in stress becomes easily to produce tendon shape protuberance.

X preferably 0.05 ＜ X ＜ 1.50, more preferably 0.10 ＜ X ＜ 1.00.

In the present invention, the maximum Y [%/m of the rate of change y absolute value of the per unit distance of x²] meet 0.1 ＜ Y ＜ 20.0 (formula (II)).If Y is less than 0.1, although mechanism is unclear, film becomes easily to produce tendon shape protuberance on the whole.If Y exceedes 20, then the position partly concentrated in stress becomes easily to produce tendon shape protuberance.

Y preferably 0.5 ＜ Y ＜ 15, more preferably 1 ＜ Y ＜ 10.

As described, tendon shape protuberance easily produces when relatively thin polyester film is carried out heating conveyance, in the present invention, Using thickness be less than 100 μm polyester film as object.The polyester film more than 100 μm for the thickness is difficult to produce tendon shape protuberance.Polyester The thickness of thin of film is then readily obtained the effect of the present invention, and the thickness of polyester film is preferably more than 5 μm and less than 75 μm, more preferably More than 10 μm and less than 63 μm.

MD from the viewpoint of suppressing tendon shape protuberance further, in the central part of width (TD direction) of polyester film Percent thermal shrinkage is preferably more than 0.01% and less than 3%.Wherein, the central part of polyester film width refers to set the TD of polyester film When the position at one end in direction and the center of another end is C, centered on C, reach respectively in TD direction and MD direction To the TD direction of polyester film total length ± 10% region.

It is set to more than 0.01% by the MD percent thermal shrinkage in the TD direction central part by polyester film, in the heating of polyester film Be difficult to produce substantially lax etc. in conveyance, can suppress easily to produce lax partly in tendon shape protuberance generation.By inciting somebody to action MD percent thermal shrinkage in the central part of TD direction is set to less than 3%, and the tendon shape producing because of thermal contraction can be suppressed to swell.

MD percent thermal shrinkage in the TD direction central part of polyester film more preferably more than 0.05% and less than 2%, further It is preferably more than 0.10% and less than 1.5%.

Additionally, the MD percent thermal shrinkage deviation from the viewpoint of suppressing tendon shape protuberance further, on the TD direction of polyester film It is preferably more than 0.01% and less than 0.5%.

Wherein, the MD percent thermal shrinkage deviation on so-called TD direction, refers to measure as shown in Figure 2 at n position P MD percent thermal shrinkage Sh when the maxima and minima of MD percent thermal shrinkage difference.

For example, the diaphragm of 11 position P1～P11 that the TD direction of polyester film is arranged at equal intervals is sampled.Survey Determine each MD percent thermal shrinkage Sh1～Sh11 of the diaphragm at P1～P11, as long as by the maxima and minima in Sh1～Sh11 Difference is as the MD percent thermal shrinkage deviation on TD direction.Hereinafter, " the MD percent thermal shrinkage deviation on TD direction " is also referred to as Δ Sh.

By making the MD percent thermal shrinkage deviation (Δ Sh) on the TD direction of polyester film be more than 0.01% although mechanism is unclear Chu, but film becomes to be difficult to produce tendon shape protuberance on the whole.By making Δ Sh be less than 0.5%, become to readily satisfy formula (I) and formula (II) generation of tendon shape protuberance can, be suppressed further.

Δ Sh more preferably less than 4%, more preferably less than 0.3%.

Polyester film passes through further by means of differential scanning calorimetry, TD direction to be measured the pre- peak temperature deviation that (DSC) measures It is set to more than 0.5 DEG C and less than 10 DEG C, can further suppress tendon shape to swell.

Wherein, so-called DSC is that means of differential scanning calorimetry measures (Differential scanning calorimetry), institute " the pre- peak temperature " of meaning DSC refers to the temperature at peak polyester film being carried out initially occur when DSC measures.

The pre- peak temperature of DSC correspond generally to polyester film biaxial stretch-formed in heat in the cross directional stretch operation that carries out fixed The highest of polyester film during type reaches film surface temperature (heat setting temperature).

In addition, the pre- peak temperature of DSC is to measure, in means of differential scanning calorimetry, the value obtained in (DSC) by conventional method.

Additionally, pre- peak temperature deviation is obtained in the same manner as MD percent thermal shrinkage deviation (Δ Sh).That is, the TD direction to polyester film On the diaphragm of 11 position P1～P11 that is arranged at equal intervals be sampled.Diaphragm at P1～P11 is carried out with DSC mensure, surveys Fixed each pre- peak temperature Tpp1～Tpp11, the difference of the maxima and minima in Tpp1～Tpp11 is set to the DSC's in TD direction Pre- peak temperature deviation.Hereinafter, " pre- peak temperature deviation of the DSC in TD direction " is also referred to as Δ Tpp.

If the TD direction MD percent thermal shrinkage of polyester film becomes excessively uniform, film becomes easily to produce tendon shape grand on the whole Rise.

It is more than 0.5 DEG C by the pre- peak temperature deviation (Δ Tpp) making the DSC in the TD direction of polyester film, can suppress The tendon shape protuberance easily producing in film entirety.

It is less than 10 DEG C by making Δ Tpp, become to readily satisfy formula (I) and formula (II), tendon shape can be suppressed further grand The generation rising.

More preferably more than 0.5 DEG C and less than 7 DEG C of Δ Tpp, further preferred more than 0.5 DEG C and less than 5 DEG C, most preferably More than 0.5 DEG C and less than 4 DEG C.

From the viewpoint of the hydrolytic resistance improving polyester film improves weatherability, the intrinsic viscosity (IV of polyester film； Intrinsic Viscosity) be preferably more than 0.55dL/g and below 0.90dL/g, more preferably more than 0.60dL/g and Below 0.80dL/g, more preferably more than 0.62dL/g and below 0.78dL/g, most preferably more than 0.63dL/g and Below 0.75dL/g.

Amount (end COOH amount (also referred to as acid number), the AV of the terminal carboxyl group of polyester film；Acid Value) preferred 5eq/ ton Above and below 35eq/ ton.COOH amount in end is more preferably below more than 6eq/ ton and 30eq/ ton, more preferably 7eq/ More than ton and below 28eq/ ton.

In addition, in this specification, " eq/ ton " represents every 1 ton of molar equivalent.

AV is that polyester is completely dissolved in benzyl alcohol/chloroform (=2/3；Volume ratio) mixed solution in, using phenol red work For indicator, titrated, the value being calculated by its titer with titer (0.025N KOH- methanol mixed solution).

Polyester film is the material making dicarboxylic acid component and diol component copolymerization and synthesizing.Become with regard to dicarboxylic acid component and glycol The details dividing, is described below.Additionally, the polyester film of the present invention preferably comprises the number (a) from carboxyl and hydroxyl Total (a+b) counting (b) is more than 3 polyfunctional monomer (hereinafter also referred to as " polyfunctional monomers more than 3 senses " or referred to as For " polyfunctional monomer ".) Component units polyester film.

The polyester film of the present invention can be led to (B) diol component by for example making (A) dicarboxylic acid component as will be described later Cross known method to carry out esterification and/or ester exchange reaction and obtain, more preferably many officials more than copolymerization thereon 3 sense Can monomer and obtain.With regard to the feelings in detail such as the illustration of dicarboxylic acid component, diol component and polyfunctional monomer etc., preferred mode Condition, as will be described later.

～from polyfunctional monomer Component units～

Composition as the polyfunctional monomer being more than 3 with total (a+b) of the number (b) of hydroxyl from the number (a) of carboxyl Unit, as will be described later, the number (a) that can include carboxyl is more than 3 carboxylic acid and their ester derivant or anhydride etc. Hydroxyl value (b) is more than 3 polyfunctional monomer and " has the number (a) of both hydroxyl and carboxyl and carboxyl in a molecule Total (a+b) with the number (b) of hydroxyl is more than 3 hydroxyl acids " etc..With regard to their illustration and preferred mode etc. in detail Situation, as will be described later.

Additionally, in the carboxyl terminal of carboxylic acid or " there is in a molecule polyfunctional monomer of both hydroxyl and carboxyl " The hydroxyl acids such as carboxyl terminal addition l- lactide, d- lactide, hydroxy benzoic acid and its derivant, this multiple company of hydroxyl acids Compound obtained from material connecing etc. also is adapted for.

They can be used alone one kind, as needed it is also possible to be used in combination multiple.

In the polyester film of the present invention, the containing ratio of the Component units of the polyfunctional monomer more than 3 senses with respect to Whole Component units of the polyester in polyester film are preferably 0.005 mole of more than % and 2.5 mole of below %.From multifunctional list The containing ratio of the Component units of body more preferably 0.020 mole of more than % and 1 mole of below %, more preferably 0.025 Mole more than % and 1 mole of below %, more preferably 0.035 mole more than % and 0.5 mole of below %, particularly preferably 0.05 mole of more than % and 0.5 mole of below %, most preferably 0.1 mole more than % and 0.25 mole of below %.

By making the Component units that there is the polyfunctional monomer more than 3 senses in polyester film, can get by from 3 officials The Component units of polyfunctional monomer more than energy branch out the structure of polyester molecule chain, can promote mutually twining between polyester molecule Around.As a result, if exposed to leading to polyester molecule to occur to hydrolyze and molecular weight reduction under hot and humid environment, by poly- Formed between ester molecule and be mutually wound around, also can suppress the embrittlement of polyester film, can get more excellent weatherability.And then, such phase The suppression being mutually wound around for thermal contraction is also effective.Speculate this is because, by the mutual winding of above-mentioned polyester molecule The mobility of polyester molecule reduces, even if so molecule is wanted because of heat to shrink also cannot shrink, the thermal contraction of polyester film obtains Suppression.

Additionally, being used as Component units by comprising the polyfunctional monomer of more than 3 senses, do not have in polycondensation after esterification Composition in the coating layer that the functional group having use is formed on polyester film with coating produces hydrogen bond, covalent bond, thus coating layer Kept better with the adhesiveness of polyester film, the generation of stripping can be effectively prevented.Make in backboard used for solar batteries Polyester film is adhered to sealants such as EVA after coating forms the coating layers such as easy adhesive layer, even being positioned over for a long time In the case of being exposed under such environment in wind and rain outside room etc., also can obtain the good adhesiveness being difficult to peel off.

Therefore, by make the polyfunctional monomer more than 3 senses Component units containing ratio be 0.005 mole of % More than, the adhesion of weatherability, low thermal shrinkage behavior and the coating layer being formed on polyester film with coating is easily improved further. Additionally, being 2.5 moles of below % by the containing ratio making the Component units of polyfunctional monomer more than 3 senses, due to The Component units volume of the polyfunctional monomer more than 3 senses is big, so can suppress to become difficult to form crystallization.Its result It is to promote the formation of low mobile composition being formed via crystallization, suppress water-disintegrable reduction.And then, by from 3 senses The large volume of the Component units of above polyfunctional monomer, the micro concavo-convex amount on film surface increases, so easily embodying grappling Effect, the adhesion of the coating layer that polyester film is formed at coating on this film improves.Additionally, passing through this large volume, the freedom of increase Volume (intermolecular gap) is inhibited, and can suppress to skid off (The りけ Ru) in big free volume because of polyester molecule And the thermal contraction producing.Additionally, producing with the excessive addition of the Component units of polyfunctional monomer more than 3 senses The reduction of glass transition temperature (Tg) is also inhibited, and is also effective for the reduction preventing weatherability.

～from end-capping reagent structure division～

The polyester film of the present invention preferably also has from selected from oxazoline based compound, carbon imidodicarbonic diamide compound and ring The structure division of the end-capping reagent in oxygen compound.In addition, " from the structure division of end-capping reagent " refers to end-capping reagent and polyester end Carboxylic acid reaction and be bonded in the structure of end.

If end-capping reagent is contained in polyester film, due to the carboxylic acid reaction of end-capping reagent and polyester end, it is bonded in polyester end End and exist, so becoming easily end COOH amount (AV value) to be stably maintained at already described preferred scope etc. desired Value.That is, the poly- ester hydrolysis being promoted by terminal carboxylic are inhibited, and can keep weatherability higher.Further, since being bonded in The end section of polyester end and strand becomes that volume is big, and the micro concavo-convex amount on film surface increases, so becoming easily to embody Go out Anchoring Effect, the adhesion of the coating layer that polyester film is formed at coating on this film improves.And then, end-capping reagent volume is big, can press down Polyester molecule processed skids off movement in free volume.As a result, also having the effect with the thermal contraction of movement of molecule for the suppression Really.

In addition, end-capping reagent is the additive making the carboxyl terminal amount of polyester reduce with the carboxyl reaction of the end of polyester.

End-capping reagent can be used alone a kind it is also possible to be applied in combination two or more.

End-capping reagent with respect to polyester film quality preferably with more than 0.1 mass % and the scope below 5 mass % contains, more It is preferably below more than 0.3 mass % and 4 mass %, more than more preferably 0.5 mass % and below 2 mass %.

By making the containing ratio of the end-capping reagent in polyester film for more than 0.1 mass %, the adhesion with coating layer becomes good Good, can reach simultaneously and be improved by the weatherability that AV reducing effect is brought, and also low thermal shrinkage behavior can be given.If additionally, The containing ratio of the end-capping reagent in polyester film is below 5 mass %, then become good with the adhesion of coating layer, simultaneously because of end-capping reagent Interpolation and the reduction of the glass transition temperature (Tg) of polyester that produces be inhibited, the weatherability thus leading to can be suppressed Reduction, the increase of thermal contraction.This is because, the relatively reactive increase of polyester because Tg reduces can be suppressed and produce Water-disintegrable increase, can suppress the mobility of the polyester molecule increasing because Tg reduces to become the heat receipts easily increasing and producing Contracting.

As the end-capping reagent in the present invention, preferably there is the compound of carbon imidodicarbonic diamide base, epoxy radicals or oxazoline base. As the specific example of end-capping reagent, can suitably include carbon imidodicarbonic diamide compound, epoxide, oxazoline based compound Deng.

The carbon imidodicarbonic diamide compound with carbon imidodicarbonic diamide base has 1 functionality carbon imidodicarbonic diamide and multi-functional carbon two acyl Imines.As 1 functionality carbon imidodicarbonic diamide, can include for example dicyclohexylcarbodiimide, diisopropylcarbodiimide, Dimethyl carbon imidodicarbonic diamide, diisobutyl carbon imidodicarbonic diamide, dioctyl carbon imidodicarbonic diamide, ter /-butylisopropyl carbon imidodicarbonic diamide, Diphenyl carbon imidodicarbonic diamide, di-t-butyl carbon imidodicarbonic diamide and two-betanaphthyl carbon imidodicarbonic diamide etc., preferably dicyclohexyl carbon Imidodicarbonic diamide, diisopropylcarbodiimide.

Additionally, as multi-functional carbon imidodicarbonic diamide, preferred degree of polymerization is 3～15 poly- carbon imidodicarbonic diamide.Poly- carbon two acyl Imines typically has the repetitives representing with "-R-N=C=N- " etc., and R represents the concatenating group of the divalents such as alkylidene, arlydene. As such repetitives, can include such as 1,5- naphthalene carbon imidodicarbonic diamide, 4,4 '-diphenyl methane carbon imidodicarbonic diamide, 4, 4 '-diphenyldimethyhnethane carbon imidodicarbonic diamide, 1,3- phenylene carbon imidodicarbonic diamide, 2,4- toluene support carbon imidodicarbonic diamide, 2,6- Toluene supports carbon imidodicarbonic diamide, 2,4- toluene supports carbon imidodicarbonic diamide and 2,6- toluene supports mixture, the hexa-methylene of carbon imidodicarbonic diamide Carbon imidodicarbonic diamide, hexamethylene-Isosorbide-5-Nitrae-carbon imidodicarbonic diamide, xyxylene carbon imidodicarbonic diamide, isophorone carbon imidodicarbonic diamide, two hexamethylenes Methylmethane -4,4 '-carbon imidodicarbonic diamide, hexahydrotoluene carbon imidodicarbonic diamide, durol dimethyl carbon imidodicarbonic diamide, 2,6- bis- are different Propyl group phenyl carbon imidodicarbonic diamide and 1,3,5- triisopropylbenzene -2,4- carbon imidodicarbonic diamide etc..

From the aspect of the generation of the isocyanates system gas that suppression leads to because of thermal decomposition, carbon imidodicarbonic diamide compound The preferably high carbon imidodicarbonic diamide compound of thermostability.In order to improve thermostability, molecular weight (degree of polymerization) is more high more preferred, more preferably The high structure of thermostability is made in the end of carbon imidodicarbonic diamide compound.Additionally, polyester feed stock resin is melted by reducing Melt the temperature of extrusion, can more effectively obtain the raising effect of weatherability brought by carbon imidodicarbonic diamide compound and thermal contraction Reducing effect.

Employ the isocyanates system gas when polyester film of carbon imidodicarbonic diamide compound keeps 30 minutes at 300 DEG C of temperature The yield of body is preferably 0 mass %～0.02 mass %.If the yield of isocyanates system gas is below 0.02 mass %, Then become to be difficult to generate bubble (space) in polyester film, accordingly, it is difficult to form the position of stress concentration, it is possible to preventing Destruction that polyester film content is also easy to produce, stripping.Thus, the adhesion and adjacent material between becomes good.

Wherein, isocyanates system gas is the gas with NCO, can include such as diisopropyl phenyl different Cyanate, 1,3,5- triisopropyl phenyl diisocyanate, 2- amino -1,3,5- triisopropyl phenyl -6- isocyanates, 4, 4 '-dicyclohexyl methyl hydride diisocyanate, isophorone diisocyanate and cyclohexyl isocyanate etc..

As the epoxide with epoxy radicals, as preferred example, epihydric alcohol ester compound, contracting can be included Water glycerol ether compound etc..

As the specific example of epihydric alcohol ester compound, glycidyl benzoate, p t butylbenzoic acid can be included Ethylene oxidic ester, to toluene acid glycidyl ester, cyclohexane-carboxylic acid ethylene oxidic ester, n-nonanoic acid ethylene oxidic ester, stearic acid shrink Glyceride, Laurel acid glycidyl ester, Petiolus Trachycarpi acid glycidyl ester, behenic acid ethylene oxidic ester, neodecanoic acid (versatic Acid) ethylene oxidic ester, Oleic acid ethylene oxidic ester, linoleic acid ethylene oxidic ester, Caulis et Folium Lini acid glycidyl ester, mountain acetylenic acid shrink Glyceride, stearolic acid ethylene oxidic ester, terephthalic acid diglycidyl ester, Diglycidyl M-phthalate, adjacent benzene Dicarboxylic acid diglycidyl ester, naphthalene dicarboxylic acids 2-glycidyl ester, methylterephthalic acid's 2-glycidyl ester, hexahydro neighbour's benzene two Formic acid 2-glycidyl ester, tetrahydrophthalic acid 2-glycidyl ester, cyclohexane dicarboxylic acid 2-glycidyl ester, adipic acid two Ethylene oxidic ester, succinic acid 2-glycidyl ester, Diglycidyl Sebacate, dodecanedioic acid 2-glycidyl ester, 18 Alkane dicarboxylic acids 2-glycidyl ester, trimellitic acid three-glycidyl ester and Pyromellitic Acid tetra glycidyl ester etc..

Additionally, as the specific example of glycidyl ether compound, phenyl glycidyl ether, O- phenyl glycidyl can be included Glycerin ether, Isosorbide-5-Nitrae-bis- (beta, gamma-glycidoxy) butane, 1,6- double (beta, gamma-glycidoxy) hexane, Isosorbide-5-Nitrae-bis- (beta, gamma-ring Oxygen propoxyl group) benzene, 1- (beta, gamma-glycidoxy) -2- Ethoxyethane, 1- (beta, gamma-glycidoxy) -2- benzyloxy second Alkane, 2,2- pair-[p- (beta, gamma-glycidoxy) phenyl] propane and 2,2- pair-(4- hydroxy phenyl) propane or 2,2- couple-(4- Hydroxy phenyl) the bisglycidyl polyethers etc. obtained from reaction by bis-phenol and epoxychloropropane such as methane.

As isoxazoline compound, can suitably select to use from the compound with oxazoline base, wherein preferably double Isoxazoline compound.

As bis-oxazoline compound, such as 2,2 '-bis- (2- oxazolines), 2,2 '-bis- (4- methyl -2- can be exemplified Oxazoline), 2,2 '-bis- (4,4- dimethyl -2- oxazolines), 2,2 '-bis- (4- ethyl -2- oxazolines), 2,2 '-bis- (4,4 '-diethyl Base -2- oxazoline), 2,2 '-bis- (4- propyl group -2- oxazolines), 2,2 '-bis- (4- butyl -2- oxazolines), 2,2 '-bis- (4- oneself Base -2- oxazoline), 2,2 '-bis- (4- phenyl -2- oxazolines), 2,2 '-bis- (4- cyclohexyl -2- oxazolines), 2,2 '-bis- (4- benzyls Base -2- oxazoline), 2,2 '-TOPOT 2,2′ p phenylenebis (2- oxazoline), 2,2 '-metaphenylene double (2- oxazoline), 2,2 '-adjacent Asia benzene Base double (2- oxazoline), 2,2 '-TOPOT 2,2′ p phenylenebis (4- methyl -2- oxazoline), 2,2 '-TOPOT 2,2′ p phenylenebis (4,4- dimethyl -2- Oxazoline), 2,2 '-metaphenylene double (4- methyl -2- oxazoline), 2, double (4, the 4- dimethyl -2- azoles of 2 '-metaphenylene Quinoline), 2,2 '-ethylenebis (2- oxazoline), 2,2 '-tetramethylene double (2- oxazoline), 2,2 '-hexamethylene bis (2- azoles Quinoline), 2,2 '-eight di-2-ethylhexylphosphine oxides (2- oxazoline), 2,2 '-decamethylene double (2- oxazoline), 2,2 '-ethylenebis (4- methyl- 2- oxazoline), 2,2 '-tetramethylene double (4,4- dimethyl -2- oxazoline), 2,2 ' -9, the double (2- of 9 '-biphenoxyl ethane Oxazoline), 2,2 '-cyclohexylidene double (2- oxazoline) and 2,2 '-diphenylene double (2- oxazoline) etc..In them, from polyester Reactivity is good and the raising effect height of weatherability from the viewpoint of, most preferably 2,2 '-bis- (2- oxazolines).

As long as bis-oxazoline compound does not damage the effect of the present invention, can be used alone a kind it is also possible to by two or more It is applied in combination.

In the present invention, polyfunctional monomers more than above-mentioned or 3 senses described later, end-capping reagent can individually use A kind of it is also possible to by they two kinds be applied in combination.

As long as the polyester film of the present invention can manufacture, to meet the thickness of formula (I) and (II) be less than 100 μm of polyester film Method then can be made by arbitrary method.In the present invention, can be by the polyester of the present invention for example shown below The manufacture method of film optimally makes.

Hereinafter, the manufacture method of the polyester film of the present invention is specifically described.

The manufacture method of the polyester film of the present invention is including following operation：

Polyester feed stock resin is melt extruded with lamellar, the film cooling down and shaping polyester film on curtain coating drum shapes Operation；

In at least one of thermal finalization portion and hot wire-CVD portion, heater is utilized to the end of the polyester film of width Carry out selective radiation heating, and, in cooling end, the surface temperature of polyester film will be made when being cooled to 70 DEG C for 150 DEG C Average cooling rate in film width end is set to 1.01 times of the average cooling rate in the central part of film width ～2 times of method.

The manufacture method of the polyester film of the present invention can also comprise other operations.

The manufacture method of the polyester film of the present invention substantially comprises film forming process, longitudinal stretching operation and cross directional stretch work Sequence.Longitudinal stretching refers to the stretching to length direction (MD direction) of polyester film, cross directional stretch refer to polyester film to width side Stretching to (TD direction).

Cross directional stretch operation is divided into preheating part, extension section, thermal finalization portion, hot wire-CVD portion and cooling end, and polyester film is transported To each portion.

And then, in the manufacture method of the polyester film of the present invention, the thermal finalization portion in cross directional stretch operation or hot wire-CVD In both portion or thermal finalization portion and hot wire-CVD portion, using heater, selectivity spoke is carried out to the TD direction end of polyester film Penetrate heating.

Above-mentioned composition is had by the manufacture method making polyester film, easy to manufacture meets already described formula (I) and the thickness of (II) Spend the polyester film for less than 100 μm, even if easy to manufacture is also difficult to when carrying out heating conveyance produce the gauffer (tendon shape in MD direction Protuberance) polyester film.

As described, in the manufacture method of conventional polyester film, also suppress gauffer, attempt size stabilization, but Polyester that is relatively thin and meeting formula (I) and (II) cannot be manufactured as the present invention.

For example in Japanese Unexamined Patent Publication 2009-149066 publication it is believed that due to following 1) and 2) shown in the reasons why, institute So that the polyester film meeting formula (I) and (II) cannot be manufactured.

1) the MD percent thermal shrinkage change of film end periphery

The MD percent thermal shrinkage of polyester film is typically by the pine of the crystallization degree of the polyester constituting film and the polyester molecule in MD direction Relaxation degree determines.The lax degree of the crystallization degree of polyester and polyester molecule is got over and is in progress, and there is MD percent thermal shrinkage becomes lower Tendency.

Generally, in the case of the PET carrying out cross directional stretch using stretching devices such as biaxial stretch-formed devices, the crystallization of PET The lax degree of change degree and PET molecule is determined by the temperature in the thermal finalization portion of stretching device.The heat setting temperature of film is higher, exists The crystallization degree of polyester is higher, polyester film MD percent thermal shrinkage becomes lower tendency.

When carrying out cross directional stretch and thermal finalization using stretching device, film is held component with clip etc. and is held, but Often from the entrance (when polyester film enters preheating part) of stretching device, through outlet, (polyester film leaves this holding component from cooling end When) and reach about 100 DEG C～150 DEG C about of temperature.Before the heat setting temperature of film generally reaches 200 DEG C in the case of pet Afterwards, but lower than heat setting temperature due to holding the temperature of component itself, so thermal runaway is to holding component side, inevitable mulch film end The easy step-down of heat setting temperature of side.Therefore, the MD percent thermal shrinkage of film is easily formed the such greatly distribution of change of film end.Cause This it is believed that producing the position that changes of the suddenly high ground of MD percent thermal shrinkage in film end periphery, become easily to produce at this position plus Tendon shape protuberance during heat conveyance.

2) the trickle variation of MD percent thermal shrinkage

Think that the situation that the MD percent thermal shrinkage of polyester film is changed with trickle spacing is also to suppress tendon shape to swell Generation the reasons why one of.

Even if the amount of change itself of polyester film MD percent thermal shrinkage is little, if the spacing changing is trickle, due to MD percent thermal shrinkage " rate of change of per unit distance " become big, so sometimes also becoming the main cause that tendon shape protuberance produces.This trickle spacing The detailed mechanism of variation do not know, but think that film is by chilling in the cooling end of stretching device, thus produce in face Trickle residual stress is uneven, causes therefrom.

Relatively thin polyester film is little due to thermal capacity, so inevitably becoming the side of chilling in the cooling end of stretching device To easily generation trickle MD percent thermal shrinkage as described above changes.Sometimes therefore become tendon shape protuberance during heating conveyance The reason.

It is believed that due to for above-mentioned 1 for conventional polyester film) and 2) countermeasure insufficient, so producing in film Raw tendon shape protuberance.

On the other hand, the manufacture method of the polyester film according to the present invention, at least in thermal finalization portion and hot wire-CVD portion In person, using heater, selective radiation heating is carried out to the end of the polyester film of width (TD direction), and, in cooling In portion, the average cooling rate in the TD direction end of film is set to average cooling rate in the central part in film TD direction 1.01 times～2 times.

Therefore, it is possible to avoid the cooling of the film TD direction end of the holding component via stretching device, the thickness of film of resulting from The chilling of the film of degree.Average cooling rate especially by the film end making in cooling end is faster than the average cooling of film central part Degree is big, can reduce the trickle variation of the MD percent thermal shrinkage of film.

As a result, already described formula is met by the relatively thin polyester film that the manufacture method of the polyester film of the present invention makes And (II) (I).

Hereinafter, for the details of the manufacture method of the polyester film of the present invention, for film forming process, longitudinal stretching Operation and each operation of cross directional stretch operation, are described in detail respectively.

(film forming process)

In film forming process, polyester feed stock resin is melt extruded with lamellar, curtain coating drum cools down and will gather Ester film shapes.

With regard to the method that melt extruded polyester feed stock resin and polyester feed stock resin, it is not particularly limited, but logical Cross catalyst, polymerization etc. used in the synthesis of polyester feed stock resin, intrinsic viscosity can be made to reach desired characteristic Viscosity.

First, polyester feed stock resin is illustrated.

(polyester feed stock resin)

As long as polyester feed stock resin becomes the raw material of polyester film and comprises the material of polyester, then it is not particularly limited, removes Beyond polyester, the slurry of inorganic particulate or organic filler can also be comprised.Additionally, polyester feed stock resin can also comprise to be derived from The titanium elements of catalyst.

The species of the polyester comprising in polyester feed stock resin is not particularly limited.

Can be synthesized using dicarboxylic acid component and diol component, it is possible to use commercially available polyester.

In the case of synthesizing polyester, can be known by making such as (A) dicarboxylic acid component and (B) diol component utilize Method carries out esterification and/or ester exchange reaction and obtains.

As (A) dicarboxylic acid component, such as malonic acid, succinic acid, 1,3-propanedicarboxylic acid, adipic acid, suberic acid, the last of the ten Heavenly stems two can be included The aliphatic such as acid, dodecanedioic acid, dimer acid, eicosane diacid, 1,5-pentanedicarboxylic acid., Azelaic Acid, Isosuccinic acid, ethyl malonic acid Omega-dicarboxylic acids, diamantane (obsolete) dicarboxylic acids, norbornene dicarboxylic acids, isosorbide, cyclohexane dicarboxylic acid, naphthalane dicarboxylic acids etc. are alicyclic Dicarboxylic acids, p-phthalic acid, M-phthalic acid, phthalic acid, Isosorbide-5-Nitrae-naphthalene dicarboxylic acids, 1,5- naphthalene dicarboxylic acids, 2,6- naphthalene dicarboxyl Acid, 1,8- naphthalene dicarboxylic acids, 4,4'-diphenyldicarboxylic acids, 4,4 '-diphenyl ether dicarboxylic acids, 5-sodium sulfo isophthalate, benzene The dicarboxylic acids such as the aromatic dicarboxylic acids such as base indane dicarboxylic acid, anthracene dicarboxylic acids, luxuriant and rich with fragrance dicarboxylic acids, 9,9 '-bis- (4- carboxyl phenyl) fluorenic acids Or its ester derivant.

As (B) diol component, such as ethylene glycol, 1,2-PD, 1,3-PD, Isosorbide-5-Nitrae-butane two can be included The alicyclic rings such as the aliphatic diol classes such as alcohol, 1,2- butanediol, 1,3- butanediol, cyclohexanedimethanol, spiral shell glycol, isosorbide The aromatic diol class such as formula glycolss, bisphenol-A, 1,3- benzene dimethanol, Isosorbide-5-Nitrae-benzene dimethanol, 9,9 '-bis- (4- hydroxy phenyl) fluorenes Deng diol compound.

As (A) dicarboxylic acid component, preferably use the situation of at least one of aromatic dicarboxylic acid.More preferably in dicarboxylic acids Aromatic dicarboxylic acid is contained as main component in composition.Can also be containing the dicarboxylic acid component beyond aromatic dicarboxylic acid.Make For such dicarboxylic acid component, it is ester derivant of aromatic dicarboxylic acid etc. etc..

In addition, so-called " main component " refers to that the shared ratio in dicarboxylic acid component of aromatic dicarboxylic acid is 80 mass % More than.

Additionally, as (B) diol component, preferably using the situation of at least one of aliphatic diol.As aliphatic two Alcohol, can comprise ethylene glycol, preferably comprise ethylene glycol as main component.

In addition, so-called main component refers to that the shared ratio in diol component of ethylene glycol is more than 80 mass %.

(particularly aromatic dicarboxylic acid is (for example with respect to dicarboxylic acid component for the usage amount of diol component (such as ethylene glycol) P-phthalic acid)) and use as desired 1 mole of its ester derivant, preferably 1.015～1.50 moles of scope. The scope that more preferably 1.02～1.30 moles of this usage amount, more preferably 1.025～1.10 moles of scope.This use If the scope that more than 1.015 moles of amount, then esterification is carried out well, if less than 1.50 moles of scope, then can press down Make the secondary generation of the diethylene glycol for example being caused by the dimerization of ethylene glycol, fusing point or glass transition can be kept well The numerous characteristics such as temperature, crystallinity, thermostability, hydrolytic resistance, weatherability.

It is 3 that polyester feed stock resin in the present invention preferably comprises the number (a) of carboxyl and total (a+b) of the number (b) of hydroxyl Above polyfunctional monomer is as copolymer composition (constituents more than 3 senses)." comprise polyfunctional monomer as copolymer composition (constituents more than 3 senses) " mean to comprise the Component units from polyfunctional monomer.

Composition as the polyfunctional monomer being more than 3 with total (a+b) of the number (b) of hydroxyl from the number (a) of carboxyl Unit, can include the Component units from carboxylic acid shown below.

As carboxyl number (a) be more than 3 carboxylic acid (polyfunctional monomer) example, as the aromatic carboxylic acid of 3 senses, Such as trimesic acid, trimellitic acid, Pyromellitic Acid, naphthalene tricarboxylic acids, anthracene tricarboxylic acids etc. can be included, as the fat of 3 senses Aliphatic carboxylic acid, can include such as methane tricarboxylic acids, ethane tricarboxylic acids, tricarballylic acid, butane tricarboxylic acid etc., as 4 senses Aromatic carboxylic acid, such as benzene tertacarbonic acid, benzophenone tetrabasic carboxylic acid, naphthalene tetracarboxylic acid, anthracene tetrabasic carboxylic acid, tetrabasic carboxylic acid can be included Deng as the aliphatic carboxylic acid of 4 senses, such as ethane tetrabasic carboxylic acid, ethylidene tetrabasic carboxylic acid, BTCA, ring penta can be included Alkane tetrabasic carboxylic acid, cyclopentanetetracarboxylic, diamantane (obsolete) tetrabasic carboxylic acid etc., as aromatic carboxylic acids more than 5 senses, can include such as benzene Pentacarboxylic acid, benzene hexacarboxylic acid, naphthalene pentacarboxylic acid, naphthalene hexacarboxylic acid, naphthalene seven carboxylic acid, naphthalene eight carboxylic acid, anthracene pentacarboxylic acid, anthracene hexacarboxylic acid, anthracene seven carboxylic Acid, anthracene eight carboxylic acid etc., as aliphatic carboxylic acids more than 5 senses, can include such as ethane pentacarboxylic acid, ethane seven carboxylic acid, fourth Alkane pentacarboxylic acid, butane seven carboxylic acid, Pentamethylene. pentacarboxylic acid, hexamethylene pentacarboxylic acid, hexamethylene hexacarboxylic acid, diamantane (obsolete) pentacarboxylic acid, Buddha's warrior attendant Alkane hexacarboxylic acid etc..

In the present invention, their ester derivant, anhydride etc. can be included as an example, but be not limited to these.

Additionally, also suitable using in the carboxyl terminal addition l- lactide of above-mentioned carboxylic acid, d- lactide, hydroxy benzoic acid Deng compound obtained from hydroxyl acids and its derivant, the multiple material being formed by connecting of this hydroxyl acids etc..

They can be used alone a kind, as needed it is also possible to be used in combination multiple.

The example of the polyfunctional monomer being more than 3 as hydroxyl value (b), as the aromatic compound of 3 senses, can enumerate Go out such as trihydroxy benzene, trihydroxynaphthalene, trihydroxy anthracene, trihydroxy chalcone, trihydroxyflavone, trihydroxy coumarin, as 3 officials The aliphatic alcohol of energy, can include such as glycerol, trimethylolpropane, propane triol, as the aliphatic alcohol of 4 senses, can arrange Enumerate such as tetramethylolmethane etc..In addition it is also preferred that being used in obtained from the above-mentioned C-terminal addition glycolss of compound Compound.

Additionally, as other polyfunctional monomers other than the above, also can include in a molecule have hydroxyl and carboxyl this Total (a+b) of the number (b) of both and the number (a) of carboxyl and hydroxyl is more than 3 hydroxyl acids.As such hydroxy acid The example of class, can include Hydroxy M Phthalic Acid, hydroxyterephthalic acid, dihydric para-phthalic acid, trihydroxy to benzene two Formic acid etc..

Additionally, also suitable using in the carboxyl terminal addition l- lactide of these polyfunctional monomers, d- lactide, hydroxy benzeness Compound obtained from the hydroxyl acids such as formic acid and its derivant, the multiple material being formed by connecting of this hydroxyl acids etc..

In polyester feed stock resin in the present invention, from Component units the containing in polyester feed stock resin of polyfunctional monomer There are whole Component units that ratio is with respect to the polyester in polyester feed stock resin, preferably 0.005 mole more than % and 2.5 rubs You are below %.From polyfunctional monomer Component units more preferably 0.020 mole more than % and 1 mole of % of containing ratio with Under, more preferably 0.025 mole more than % and 1 mole of below %, more preferably 0.035 mole more than % and 0.5 Mole below %, particularly preferably 0.05 mole more than % and 0.5 mole of below %, most preferably 0.1 mole more than % and 0.25 mole of below %.

By making the Component units that there is the polyfunctional monomer more than 3 senses in polyester feed stock resin, such as above-mentioned that Sample, when polyester film shapes the most at last, the functional group being not used by polycondensation is formed in the coating layer on polyester film with coating Composition produce hydrogen bond, covalent bond, thus coating layer is kept better with the adhesiveness of polyester film, can effectively prevent stripping From generation.Additionally, obtaining being branched out the knot of polyester molecule chain by the Component units of the polyfunctional monomer more than 3 senses Structure, can promote the mutual winding between polyester molecule.

In esterification and/or ester exchange reaction, it is possible to use known catalysts all the time.Anti- as this Answer catalyst, alkali metal compound, alkaline earth metal compound, zinc compound, lead compound, manganese compound, cobalt can be included Compound, aluminium compound, antimonial, titanium compound, phosphorus compound etc..Generally, it is preferred to before the manufacture method of polyester completes The arbitrary stage, as polymerization catalyst add antimonial, germanium compound, titanium compound.As such method, if taking For example as a example germanium compound, then preferably directly add germanium compound powder body.

Such as esterification operation depositing in the catalyst containing titanium compound by aromatic dicarboxylic acid and aliphatic diol Under be polymerized.In this esterification operation, as the titanium compound of catalyst, having using organic acid as part is used Machine chelates titanium complex, simultaneously at least provided with adding organic Ti chelator complex, magnesium compound successively, do not have virtue in operation The process of the phosphate ester as 5 valencys of substituent group for the fragrant ring and constitute.

First, before adding magnesium compound and phosphorus compound, by aromatic dicarboxylic acid and aliphatic diol with contain titanium Compound is the catalyst mixing of organic chelated titanium complex.Because the titanium compounds such as organic chelated titanium complex are with respect to esterification Reaction also has high catalysis activity, it is possible to carrying out esterification well.At this point it is possible to by dicarboxylic acid component and two After during the mixing of alcohol composition, interpolation titanium compound it is also possible to mix dicarboxylic acid component's (or diol component) with titanium compound Mixing diol component (or dicarboxylic acid component).Further, it is also possible to dicarboxylic acid component is mixed with titanium compound with diol component simultaneously Close.Mixing is not particularly limited to its method, can be carried out by known method.

Preferred polyester is polyethylene terephthalate (PET), poly- NDA glycol ester (PEN), More preferably PET.And then, PET preferably uses and urges selected from germanium (Ge) series catalysts, antimony (Sb) series catalysts, aluminum (Al) system The one kind or two or more material being polymerized in agent and titanium (Ti) series catalysts, more preferably Ti series catalysts.

The reactivity of Ti series catalysts is high, can reduce polymerization temperature.Therefore, particularly can suppress in polyreaction Middle polyester occurs thermal decomposition to produce COOH.That is, by using Ti series catalysts, the poly- of the reason become thermal decomposition can be reduced The amount of the terminal carboxylic of ester, can suppress foreign body to be formed.By the amount of the terminal carboxylic of reduction polyester additionally it is possible to suppression is manufacturing After polyester film, polyester film thermally decomposes.

As Ti series catalysts, oxide, hydroxide, alkoxide, carboxylate, carbonate, oxalates, organic can be included Chelating titanium complex and halogenide etc..As long as Ti series catalysts do not damage the scope of the effect of the present invention, then can also be by two Plant above titanium compound to be used in combination.

As the example of Ti series catalysts, can include metatitanic acid four n-propyl, tetraisopropyl titanate, tetra-n-butyl titanate, The titanium alcohol such as tetra-n-butyl titanate tetramer, metatitanic acid four tert-butyl ester, metatitanic acid four cyclohexyl, metatitanic acid tetraphenyl ester, metatitanic acid tetrabenzyl ester Salt, by Titanium alkoxides titanium oxide obtained from hydrolysis, by the hydrolysis of Titanium alkoxides and the mixture of silicon alkoxide or zirconium alkoxide Obtained from titanium-silicon or zirconium mixed oxide, acetic acid titanium, titanium oxalate, titanium potassium oxalate, titanium oxalate sodium, potassium titanate, sodium titanate, titanium Acid-alumag, titanium chloride, titanium chloride-aluminum chloride mixture, titanium acetylacetone, having using organic acid as part Machine chelating titanium complex etc..

When being polymerized polyester, exist 50ppm below, in more than 1ppm and more preferably preferably in terms of titanium elements scaled value More than 2ppm and below 30ppm, the further preferred titanium being used in more than 3ppm and in the scope of below 15ppm as catalyst (Ti) compound is polymerized.In this case, in polyester feed stock resin, containing more than 1ppm and below 50ppm titanium unit Element.

If the amount of the titanium elements comprising in polyester feed stock resin is more than 1ppm, in the weight average molecular weight (Mw) of polyester Rise it is difficult to thermally decompose.Therefore, in extruder, foreign body reduces.If the amount of the titanium elements comprising in polyester feed stock resin is Below 50ppm, then Ti series catalysts be difficult to become foreign body, in the stretching of polyester film stretching inequality be mitigated.

[titanium compound]

As the titanium compound of catalyst component, preferably use using organic acid as the organic chelated titanium complex of part At least one.As organic acid, such as citric acid, lactic acid, trimellitic acid, malic acid etc. can be included.Wherein, preferably with Fructus Citri Limoniae Acid or citrate as part organic chelated complex.

When being used for example using citric acid as the chelating titanium complex of part, the generation of the foreign body such as minuteness particle is few, with it His titanium compound is compared, and can get polymerization activity and the good polyester of tone.And then, chelating titanium complex using citric acid When, the method being added also by the stage in esterification, compared with situation about being added after esterification, can obtain To polymerization activity and tone be good and the few polyester of terminal carboxyl group.With regard to this point, estimate titanium catalyst and also there is esterification Catalytic effect, by being added in Esterification Stage, oligomer acid number step-down at the end of esterification, later polycondensation is anti- Should be more effectively carried out, using citric acid, as compared with the complex of part and Titanium alkoxides etc., hydrolysis patience is high in addition, anti-in esterification Should during will not hydrolyze, in the state of maintaining original activity as be esterified and polycondensation reaction catalyst efficiently Function.

Furthermore it is known that general terminal carboxyl group amount more at most hydrolytic resistance more deteriorates, but last by above-mentioned adding method End carboxyl quantitative change is few, such that it is able to expect the raising of hydrolytic resistance.

Chelate titanium complex as citric acid, such as the VERTEC AC-420 etc. of Johnson Matthey company system Commercially available product can be readily available.

Aromatic dicarboxylic acid and aliphatic diol can comprise their slurry by preparation, and are continuously fed to Import in esterification operation.

Additionally, as titanium compound, in addition to organic chelated titanium complex, typically, oxide, hydroxide can be included Thing, alkoxide, carboxylate, carbonate, oxalates and halogenide etc..As long as not damaging the scope of the effect of the present invention, then except Beyond organic chelated titanium complex, can also and with others titanium compounds.

As the example of such titanium compound, metatitanic acid four n-propyl, tetraisopropyl titanate, the positive fourth of metatitanic acid four can be included The titaniums such as ester, tetra-n-butyl titanate tetramer, metatitanic acid four tert-butyl ester, metatitanic acid four cyclohexyl, metatitanic acid tetraphenyl ester, metatitanic acid tetrabenzyl ester Alkoxide, by Titanium alkoxides titanium oxide obtained from hydrolysis, by the water of Titanium alkoxides and the mixture of silicon alkoxide or zirconium alkoxide Titanium-silicon obtained from solution or zirconium mixed oxide, acetic acid titanium, titanium oxalate, titanium potassium oxalate, titanium oxalate sodium, potassium titanate, sodium titanate, Metatitanic acid-alumag, titanium chloride, titanium chloride-aluminum chloride mixture, titanium acetylacetone etc..

In the present invention, the manufacture method of the polyester preferably being constituted by arranging following operation makes, and described operation is： Esterification operation, aromatic dicarboxylic acid and aliphatic diol are polymerized in the presence of the catalyst containing titanium compound While, at least one of titanium compound is organic chelated titanium complex using organic acid as part, including at least adding successively Added with machine chelating titanium complex, magnesium compound and the process without the phosphate ester as 5 valencys of substituent group for the aromatic rings；And polycondensation Operation, makes the esterification reaction product generating in esterification operation carry out polycondensation reaction and generate condensation polymer.

In this case, during esterification, it is used as titanium compound and there is organic Ti chelator network by being set in Period of compound adds magnesium compound, then adds the order of addition of the phosphorus compound of specific 5 valencys such that it is able to appropriateness highland Keep the reactivity of titanium catalyst, give and characteristic is applied by the electrostatic that magnesium ribbon comes, and effectively suppress the decomposition in polycondensation Reaction, so result is the xanthochromia that can obtain colouring less, having when high electrostatic applies characteristic and is exposed under high temperature obtain The polyester improving.

Thereby, it is possible to provide coloring during coloring and subsequent melted masking during polymerization to tail off, with conventional antimony (Sb) The polyester of catalyst system is compared yellow sense and is mitigated, additionally, the polyester with the germanium catalyst system higher unlike the transparency is inferior Tone, the transparency, and the polyester of excellent heat resistance.Furthermore, it is possible to not use the hue adjustment material such as cobalt compound, pigment Obtain having the few polyester of the high transparency, yellow sense in the case of material.

This polyester can be used in purposes (such as optical film, the industrial lithographic plate print that have high demands relevant with the transparency Brush etc.), due to there is no need the germanium series catalysts using high price, so significantly cost can be sought reducing.Further, since also may be used To avoid being mixed into of foreign body resulting from catalyst easily being produced by Sb catalyst system, so the sending out of the fault in film-forming process Raw, the bad mitigation of quality, can also seek the cost degradation being improved and being brought by yield.

When carrying out esterification, it is preferably provided with adding successively organic chelated titanium complex as titanium compound, conduct The process of the phosphorus compound of the magnesium compound of additive and 5 valencys.At this point it is possible in the presence of organic chelated titanium complex, enter Row esterification, then started to add magnesium compound before adding phosphorus compound.

[phosphorus compound]

As the phosphorus compound of 5 valencys, at least one of the phosphate ester that there are no aromatic rings as 5 valencys of substituent group is used. The phosphate ester ((OR) that for example there is the low alkyl group that carbon number is less than 2 as substituent group can be included₃- P=O；R=carbon Atomic number is 1 or 2 alkyl), specifically, particularly preferred trimethyl phosphate, triethyl phosphate.

As the addition of phosphorus compound, preferably P element scaled value reaches the scope of more than 50ppm and below 90ppm Amount.The amount of phosphorus compound is more preferably up to the amount of more than 60ppm and below 80ppm, more preferably reach more than 60ppm and The amount of below 75ppm.

[magnesium compound]

By comprising magnesium compound in the polyester, the electrostatic imposing of polyester improves.In this case although easily Color, but in the present invention, can suppress to colour and obtain excellent tone, thermostability.

As magnesium compound, the such as magnesium salt such as magnesium oxide, magnesium hydroxide, magnesium alkoxide, magnesium acetate, magnesium carbonate can be included. Wherein, from from the viewpoint of the dissolubility ethylene glycol, most preferably magnesium acetate.

As the addition of magnesium compound, in order to give high electrostatic imposing, preferably Mg element scaled value reaches 50ppm The amount of the scope of above amount, more preferably up to more than 50ppm and below 100ppm.The addition of magnesium compound is giving electrostatic The aspect of imposing preferably up to more than 60ppm and the amount of the scope of below 90ppm, more preferably reach 70ppm with The amount of the upper and scope of below 80ppm.

In esterification operation, particularly preferably meet following relational expressions (ii) according to value Z being calculated by following formula (i) Mode add the titanium compound as catalyst component and the magnesium compound as additive and phosphorus compound and so that it is melted The situation of polymerization.Wherein, P content is the phosphorus amount of the phosphorus compound entirety carrying out the self-contained phosphate ester of 5 valencys without aromatic rings, Ti content is the titanium amount from the Ti compound entirety comprising organic Ti chelator complex.So, by selecting to comprise titanizing conjunction Being used in combination of magnesium compound in the catalyst system of thing and phosphorus compound, and control its interpolation opportunity and adding proportion, thus can fit Degree highland maintains the catalysis activity of titanium compound, can get the few tone of yellow sense simultaneously, even if in polyreaction or thereafter Masking when (during melting) etc. be exposed under high temperature it is also possible to give the thermostability being not likely to produce yellow coloring.

(i) Z=5 × (P content [ppm]/P atomic weight) -2 × (Mg content [ppm]/Mg atomic weight) -4 × (Ti content [ppm]/Ti atomic weight)

(ii)0≤Z≤+5.0

Because phosphorus compound acts not only on titanium, but also interact with magnesium compound, so it is as quantitatively The index of the balance of embodiment.

Formula (i) is to embody to deduct from the whole phosphorus amounts that can react to act on the phosphorus amount of magnesium and can act on the phosphorus of titanium Amount formula.In the case of being just in value Z, the phosphorus of titanium is hindered to be in the situation of surplus, on the contrary, in the case of for bearing, can It is in hinder the not enough situation of the phosphorus needed for titanium with saying.In the reaction, due to each 1 atom the non-equivalence of Ti, Mg, P, So valence mumber being multiplied by by the molal quantity of each in formula and being weighted.

In the present invention it is not necessary to special synthesis etc., using titanium compound that is cheap and being readily available, phosphorus compound, Magnesium compound, can obtain having reactivity necessary to reaction and tone and excellent with respect to hot coloring patience poly- Ester material resin.

In formula (ii), in the state of keeping polymerisation reactivity, from improving tone further and with respect to hot coloring From the viewpoint of patience, preferably meet the situation of+1.0≤Z≤+ 4.0, more preferably meet the situation of+1.5≤Z≤+ 3.0.

As the preferred mode in the present invention, in the following manner can be included：Before esterification terminates, to aromatic series Add in dicarboxylic acids and aliphatic diol with Ti element scaled value be calculated as more than 1ppm and below 30ppm with citric acid or Fructus Citri Limoniae After hydrochlorate is as the chelating titanium complex of part, in the presence of this chelating titanium complex, add and be calculated as with Mg element scaled value The magnesium salt of the weak acid of more than 60ppm and below 90ppm (more preferably more than 70ppm and below 80ppm), in this interpolation laggard Step is added and is calculated as more than 60ppm and below 80ppm (more preferably more than 65ppm and below 75ppm) no with P element scaled value There is the phosphate ester as 5 valencys of substituent group for the aromatic rings.

In above-mentioned, with regard to the phosphoric acid of chelating titanium complex (organic chelated titanium complex) and magnesium salt (magnesium compound) and 5 valencys Ester each, the mode preferably each more than 70 mass % of total addition level added in order.

Esterification can use the multi-stag device that is formed by connecting of at least 2 reactors in series ground, enters in ethylene glycol Under conditions of row backflow, the water being generated by reaction or alcohol are removed to outside system, is carried out simultaneously.

Additionally, above-mentioned esterification can carry out with a stage carrying out it is also possible to be divided into multiple stages.

In the case of carrying out esterification with a stage, esterification reaction temperature is preferably 230～260 DEG C, more preferably For 240～250 DEG C.

It is being divided in the case that multiple stages carry out esterification, the temperature of the esterification of the first reactive tank is preferably 230～260 DEG C, more preferably 240～250 DEG C, pressure is preferably 1.0～5.0kg/cm², more preferably 2.0～3.0kg/cm². The temperature of the esterification of the second reactive tank be preferably 230～260 DEG C, more preferably 245～255 DEG C, pressure be preferably 0.5～ 5.0kg/cm², more preferably 1.0～3.0kg/cm².Be further separated into 3 more than the stage implemented in the case of, middle The condition of the esterification in stage is preferably set to the condition between the first reactive tank and end reaction groove.

- polycondensation-

Polycondensation is so that the esterification reaction product generating in the esterification reaction is carried out polycondensation reaction and generate condensation polymer.Polycondensation is anti- Should carry out with 1 stage carrying out it is also possible to be divided into multiple stages.

The esterification reaction products such as the oligomer generating in the esterification reaction are next for polycondensation reaction.This polycondensation reaction can With by suitably carrying out in supply to multistage polycondensation reaction groove.

For example, with regard to polycondensation reaction condition when carrying out in the reactive tank in 3 stages, the reaction temperature of the preferably first reactive tank Spend for 255～280 DEG C, more preferably 265～275 DEG C, pressure is 100～10torr (13.3 × 10^-3～1.3 × 10^-3MPa)、 More preferably 50～20torr (6.67 × 10^-3～2.67 × 10^-3MPa), the reaction temperature of the second reactive tank is 265～285 DEG C, more preferably 270～280 DEG C, pressure is 20～1torr (2.67 × 10^-3～1.33 × 10^-4), more preferably 10 MPa～ 3torr(1.33×10^-3～4.0 × 10^-4MPa), the reaction temperature of the 3rd reactive tank in end reaction groove is 270～290 DEG C, more preferably 275～285 DEG C, pressure is 10～0.1torr (1.33 × 10^-3～1.33 × 10^-5), more preferably 5 MPa～ 0.5torr(6.67×10^-4～6.67 × 10^-5MPa mode).

In the polyester feed stock resin synthesizing as described above, can also contain further Photostabilised dose, antioxidant, The additives such as UV absorbent, fire retardant, easy lubrication prescription (microgranule), nucleator (crystallization agent), crystallization Inhibitorses.

In the present invention, from the viewpoint of the hydrolytic resistance of polyester film, the intrinsic viscosity (IV) of polyester feed stock resin is preferably For more than 0.55dL/g and below 0.90dL/g.Wherein, more preferably more than 0.60dL/g and below 0.80dL/g, excellent further Elect more than 0.62dL/g and below 0.78dL/g, most preferably more than 0.63dL/g and below 0.78dL/g as.

Intrinsic viscosity (IV) is by by solution viscosity (η) and solvent viscosity (η₀) ratio η_r(=η/η₀；Relative viscosity) deduct Specific viscosity (η obtained from 1_sp=η_r- 1) it is extrapolated to value obtained from the state that concentration is zero divided by value obtained from concentration.IV Using Ubbelohde viscometer, polyester is dissolved in sym.-tetrachloroethane/phenol (=2/3 [mass ratio]) mixed solvent, by 25 DEG C of solution viscosity is tried to achieve.

(melt extruding)

In film forming process in the present invention, will operate as explained above obtained from polyester feed stock resin melting squeeze Go out, cooled down further and polyester film is shaped.

For the melt extruding of polyester feed stock resin, such as using the extruder of the screw rod possessing 1 or more than 2, It is heated to the temperature of more than the fusing point of polyester feed stock resin, so that screw rod is rotated and carry out melting mixing and carry out simultaneously.Polyester raw material Resin passes through heating and the mixing using screw rod, melts and become melt in extruder.Additionally, the heat in suppression extruder From the viewpoint of decomposing (poly- ester hydrolysis), after carrying out nitrogen displacement in preferred pair extruder, carry out the melting of polyester feed stock resin Extrusion.Extruder preferred double screw extruder from the aspect of lower suppressing melting temperature.

The polyester feed stock resin (melt) having melted is extruded from extrusion mould through gear pump, filter etc..Extrusion mould Referred to as " mould " is (with reference to JIS B8650：2006th, a) extrusion shaper, numbering 134).

Now, melt can be with monolayer extrusion it is also possible to multilayer extrusion.

In polyester feed stock resin, preferably comprise selected from oxazoline based compound, carbon imidodicarbonic diamide compound and epoxidation End-capping reagent in compound.In this case, in film forming process, be added with end-capping reagent polyester feed stock resin be melted mixed Refining, the polyester feed stock resin being reacted with end-capping reagent in melting mixing is melt extruded.

Make in polyester feed stock resin, to comprise the operation of end-capping reagent by setting, weatherability improves, and can lower press down Heat contraction.Additionally, in the case of shaping polyester film, it is bonded to polyester end and the end section of strand becomes volume Greatly, the micro concavo-convex amount on film surface increases, so easily embodying Anchoring Effect, polyester film is formed at the painting on this film with coating The adhesion of layer of cloth improves.

As long as the interpolation period of end-capping reagent from raw material put into during till extrusion with polyester feed stock resin one Act the stage of mixing of being melted, be then not particularly limited, but end-capping reagent preferably delivered to screw rod after raw material is put into rotating cylinder logical Period before air port adds, and for melting mixing together with material resin.For example former in the rotating cylinder carrying out melting mixing Between material input port and vent, the supply mouth of setting supply end-capping reagent, can be added directly in the material resin in rotating cylinder. Now, end-capping reagent may be added to heating mixing start but be not fully achieved in the polyester feed stock resin of molten condition it is also possible to It is added in the polyester feed stock resin (melt) of molten condition.

As end-capping reagent with respect to polyester feed stock resin amount, the gross mass preferably with respect to polyester feed stock resin is More than 0.1 mass % and below 5 mass %.The preferred amount with respect to polyester feed stock resin of end-capping reagent be 0.3 mass % with Above and below 4 mass %, more than more preferably 0.5 mass % and below 2 mass %.

It is more than 0.1 mass % by the containing ratio that makes end-capping reagent, not only can reach and be brought by AV reducing effect Weatherability improves, and can also impart to low thermal shrinkage behavior and adhesiveness.If additionally, the containing ratio of end-capping reagent is below 5 mass %, Then in addition to adhesiveness raising, the glass transition temperature (Tg) of polyester leading to because of the interpolation of end-capping reagent can also be suppressed Reduction, the reduction of weatherability, the increase of thermal contraction thereby resulting in can be suppressed.This is because, can suppress to reduce because of Tg And the water-disintegrable increase that relatively reactivity of polyester increases and produces, the polyester molecule increasing because Tg reduces can be suppressed Mobility become the thermal contraction that easily increases and produce.

The illustration of carbon imidodicarbonic diamide compound, epoxide and oxazoline based compound and preferred mode etc. are in detail Situation is as already described in the item of " polyester film ".

By extruding melt (polyester) on curtain coating drum from mould, it is membranaceous for can shaping (curtain coating process).

By curtain coating process obtained from the thickness of membranaceous polyester formed body be preferably 0.1mm～3mm, more preferably 0.2mm～2mm, more preferably 0.3mm～1.5mm.

By the thickness of membranaceous polyester formed body is set to below 3mm, can avoid leading to because of the accumulation of heat of melt Cooling postpones, additionally, by being set to more than 0.1mm, from the period being expressed into cooling, the OH base in polyester, COOH basal orientation gather Ester diffusion inside, suppression becomes the OH base of main cause of hydrolysis generation and COOH base exposes in surface of polyester.

The method of melt cooling of extrusion will be not particularly limited from extrusion mould, as long as to melt blow cold wind and (the cooling curtain coating drum) contact of curtain coating drum or spray water.Cooling means can only carry out a kind it is also possible to combine two or more Carry out.

With regard to cooling means, above-mentioned in, from prevent oligomer to continuously run when film surface attachment from the viewpoint of, Cooling preferably by cold wind and employ curtain coating drum cooling at least one.And then, particularly preferably will be from extruder The melt cold front heavy rain of extrusion, and so that melt is contacted with curtain coating drum and be cooled down.

Additionally, the polyester formed body using coolings such as curtain coating drums is stripped component from coolings such as curtain coating drums using angle stripper etc. Strip on component.

(longitudinal stretching operation)

In the longitudinal stretching operation of the present invention, will be indulged along its length using the polyester film that film forming process shapes To stretching.

The longitudinal stretching of film for example can be by passing through 1 pair of niproll of clamping film, along the length direction conveyance of film by film Film, applies tension force to carry out between the above niproll of 2 couple of the conveyance direction arrangement along film simultaneously.Specifically, for example In the setting 1 of the conveyance direction upstream side of film to niproll A, when downstream setting 1 is to niproll B, when transporting film, by making The rotating speed of the niproll A of the rotating ratio upstream side of the niproll B in downstream is fast, thus film is carried out along conveyance direction (MD direction) Stretching.Alternatively, it is also possible to arrange 2 respectively independently of one another to above niproll in upstream side, downstream.Additionally, polyester film Longitudinal stretching can also be carried out using the longitudinal tensile fixture possessing above-mentioned niproll.

In longitudinal stretching operation, the longitudinal stretching multiplying power of polyester film is preferably 2～5 times, more preferably 2.5～4.5 times, More preferably 2.8～4 times.

Additionally, be preferably the area of the polyester film before stretching with the area stretch multiplying power of the product representation of stretching ratio in length and breadth 6 times～18 times, more preferably 8 times～17.5 times, more preferably 10 times～17 times.

With regard to polyester film longitudinal stretching when temperature (hereinafter also referred to as " longitudinal drawing temperature "), setting polyester film When glass transition temperature is Tg, preferably more than Tg-20 DEG C and less than Tg+50 DEG C, more preferably more than Tg-10 DEG C and Tg+ Less than 40 DEG C, more preferably more than Tg DEG C and less than Tg+30 DEG C.

In addition, as the means of heating polyester film, in the case of being stretched using rollers such as niprolls, can pass through Setting heater or the pipe arrangement that hot solvent can be flow through inside roller, and the polyester film being contacted with roller is heated.Additionally, not Using in the case of roller it is also possible to be contacted with thermals source such as heaters or the vicinity through thermal source by blowing hot blast to polyester film And polyester film is heated.

In the manufacture method of the polyester film of the present invention, including the cross directional stretch work described later different from longitudinal stretching operation Sequence.Therefore, in the manufacture method of the polyester film of the present invention, become by polyester film along polyester film length direction (conveyance direction, MD) stretched with least 2 axles in the direction (TD direction) vertical with the length direction of polyester film.To MD direction and TD direction As long as stretching at least carry out 1 time respectively.

In addition, so-called " direction (TD) vertical with the length direction (conveyance direction, MD) of polyester film " refers to and polyester film The angle of length direction (conveyance direction, MD) vertical (90 °) direction, but comprise due to machine error etc. substantially relatively In the angle of length direction (i.e. conveyance direction), to be considered as 90 ° of direction (be 90 ° ± 5 ° of side for example with respect to MD direction To).

As biaxial stretch-formed method, except separately carry out the gradually biaxial stretching method of longitudinal stretching and cross directional stretch with Carry out outward or simultaneously biaxial stretching method while longitudinal stretching and cross directional stretch, no matter any.Longitudinally draw Stretch and can also carry out independently of one another more than 2 times with cross directional stretch, the order of longitudinal stretching and cross directional stretch does not limit.Can include Such as longitudinal stretching → cross directional stretch, longitudinal stretching → cross directional stretch → longitudinal stretching, longitudinal stretching → longitudinal stretching → laterally The stretching modes such as stretching, cross directional stretch → longitudinal stretching.Wherein preferably longitudinally stretching → cross directional stretch.

(cross directional stretch operation)

Then, the cross directional stretch operation in the present invention is described in detail.

Cross directional stretch operation in the present invention is along the width side vertical with length direction by the polyester film after longitudinal stretching To the operation carrying out cross directional stretch, by polyester film is transported successively to following portion：

(a) by the polyester film after longitudinal stretching be preheated to the preheating part of the temperature that can stretch,

B () applies tension force to preheated polyester film along the width vertical with length direction and carries out cross directional stretch Extension section,

C () carries out to the polyester film carrying out after longitudinal stretching and cross directional stretch heating makes its crystallization and the heat of thermal finalization is fixed Type portion,

D () heats to the polyester film through thermal finalization, the tension recovery of polyester film is removed the overstrain of striping Hot wire-CVD portion and

E cooling end that polyester film after hot wire-CVD is cooled down by (),

In at least one of (c) thermal finalization portion and (d) hot wire-CVD portion, heating is utilized to the TD direction end of polyester film Device carries out selective radiation heating, and, in (e) cooling end, the surface temperature making polyester film is cooled to 70 DEG C from 150 DEG C When film width end in average cooling rate be set to the average cooling rate in the central part of film width 1.01 times～2 times carrying out this cross directional stretch.

In cross directional stretch operation in the present invention, as long as polyester film is in the way of above-mentioned composition is by cross directional stretch, then Its specific means does not limit, but preferably uses the cross directional stretch dress that can carry out forming the process of each operation of above-mentioned composition Put or biaxial stretcher is carrying out.

- biaxial stretcher-

As shown in Figure 3, biaxial stretcher 100 possesses 1 couple of annular orbit 60a and 60b and is installed on each ring-type On track and can be along the holding component 2a～2l of track movement.Annular orbit 60a and 60b clamping polyester film 200 and each other Balanced configuration, by using hold component 2a～2l grip polyester film 200 so as to along track mobile such that it is able to along film width Degree direction is stretched.

Biaxial stretcher 100 is made up of the region that following portion is formed, and described each portion is：Pre- to carry out polyester film 200 Heat preheating part 10, by polyester film 200 along the direction vertical with arrow MD direction be arrow TD direction stretched and to polyester Film applies the extension section 20 of tension force, the thermal finalization portion heated in the state of applying tension force to the polyester film being applied with tension force 30th, the polyester film heating through thermal finalization by the hot wire-CVD portion 40 of the tension recovery of the polyester film through thermal finalization and will be passed through The cooling end 50 of the polyester film cooling behind hot wire-CVD portion.

On annular orbit 60a, be provided with can along the holding component 2a of annular orbit 60a movement, 2b, 2e, 2f, 2i and 2j, in addition on annular orbit 60b, be provided with can along the holding component 2c of annular orbit 60b movement, 2d, 2g, 2h, 2k and 2l.Hold the end that component 2a, 2b, 2e, 2f, 2i and 2j hold the TD direction of polyester film 200, hold structure Part 2c, 2d, 2g, 2h, 2k and 2l hold another end in the TD direction of polyester film 200.Hold component 2a～2l to be commonly referred to as Fixture, clip etc..

Hold component 2a, 2b, 2e, 2f, 2i and 2j move counterclockwise along annular orbit 60a, hold component 2c, 2d, 2g, 2h, 2k and 2l move clockwise along annular orbit 60b.

Hold the end that component 2a～2d holds polyester film 200 in preheating part 10, along ring-type in the state of gripping Track 60a or 60b moves, the hot wire-CVD portion 40 that stretched portion 20, holding component 2e～2h are located, and advances to holding component 2i The cooling end 50 that～2l is located.Afterwards, hold component 2a and 2b and hold component 2c and 2d according to conveyance direction order in cooling After the end of polyester film 200 is left in the end in the MD direction downstream in portion 50, move further along annular orbit 60a or 60b, Return to preheating part 10.Now, polyester film 200 is mobile and carry out preheating in preheating part 10, extension section successively along arrow MD direction Cooling in hot wire-CVD in thermal finalization in stretching in 20, thermal finalization portion 30, hot wire-CVD portion 40, cooling end 50, horizontal Stretching.Holding translational speed in each region such as preheating part for the component 2a～2l becomes the conveyance speed of polyester film 200.

Hold component 2a～2l and can change translational speed independently of one another.

Biaxial stretcher 100 can enter to be about to the cross directional stretch that polyester film 200 stretches along TD direction in extension section 20, leads to Cross and change the translational speed holding component 2a～2l, polyester film 200 can also be stretched along MD direction.I.e. it is also possible to make Carry out simultaneously biaxial drawing with biaxial stretcher 100.

The holding component holding the end in TD direction of polyester film 200 only illustrates 2a～2l in figure 3, but in order to support Polyester film 200, biaxial stretcher 100 is also equipped with holding component (not shown) in addition to 2a～2l.In addition, it is following, sometimes It is generically and collectively referred to as " holding component 2 " by holding component 2a～2l.

(a. preheating part)

In preheating part, the polyester film after longitudinal stretching in longitudinal stretching operation is preheated to the temperature that can stretch.

As shown in Figure 3, in preheating part 10, polyester film 200 is preheated.In preheating part 10, by polyester film Heated in advance so that the cross directional stretch of polyester film 200 becomes able to easily carry out before 200 stretchings.

Film surface temperature with regard to preheating part end point is (hereinafter also referred to as " preheating temperature ".), in the glass setting polyester film 200 When glass transition temperature is Tg, preferably Tg-10 DEG C～Tg+60 DEG C, more preferably Tg DEG C～Tg+50 DEG C.

In addition, preheating part end point refers to terminate the moment of preheating of polyester film 200, i.e. polyester film 200 is from preheating part 10 Region position away from.

(b. extension section)

In extension section, to the polyester film having preheated in preheating part along the width side vertical with length direction (MD direction) Apply tension force to (TD direction) and carry out cross directional stretch.

As shown in Figure 3, in extension section 20, by the polyester film having preheated 200 at least edge and polyester film 200 The vertical TD direction of length direction carries out cross directional stretch and applies tension force to polyester film 200.

Stretching (cross directional stretch) to the vertical direction (TD) of the length direction (conveyance direction, MD) with polyester film 200 is Refer to along being stretched with the direction of the angle of the length direction (conveyance direction, MD) vertical (90 °) of polyester film 200 but it is also possible to It is the direction of the scope of machine error.The scope of so-called machine error is length direction (the conveyance side being considered as with polyester film To, MD) direction of vertical angle (90 ° ± 5 °).

In extension section 20, the area stretch multiplying power (each stretching ratio is long-pending) of polyester film 200 is preferably gathering before stretching 6 times of the area of ester film 200～18 times, more preferably 8 times～17.5 times, more preferably 10 times～17 times.

Additionally, with regard to polyester film 200 cross directional stretch when film surface temperature (hereinafter also referred to as " transverse drawing temperature ".), When setting the glass transition temperature of polyester film 200 as Tg, preferably more than Tg-10 DEG C and less than Tg+100 DEG C, more preferably More than Tg DEG C and less than Tg+90 DEG C, more preferably more than Tg+10 DEG C and less than Tg+80 DEG C.

As described above, holding component 2a～2l can change translational speed independently of one another.Thus, for example it is it is also possible to logical The translational speed crossing the holding component 2 making the extension section 20MD direction downstream such as extension section 20, thermal finalization portion 30 is than preheating part 10 In holding component 2 translational speed fast, and concurrently enter to be about to the longitudinal direction that polyester film 200 stretches along conveyance direction (MD direction) Stretching.

The longitudinal stretching of the polyester film 200 in cross directional stretch operation can only carry out it is also possible to rear in extension section 20 Carry out in thermal finalization portion 30, hot wire-CVD portion 40 or the cooling end 50 stated.Longitudinal stretching can also be carried out in multiple positions.

(c. thermal finalization portion)

In thermal finalization portion, by have been carried out the heating of the polyester film after longitudinal stretching and cross directional stretch make its crystallization and Carry out thermal finalization.

So-called thermal finalization directly heats in the state of referring to apply tension force to polyester film 200 in extension section 20 and makes polyester Crystallization.

In thermal finalization portion 30 shown in figure 3, for the polyester film 200 being applied with tension force, preferably by polyester film 200 The highest on surface reach film surface temperature (in this specification, also referred to as " heat setting temperature ", " T_{Thermal finalization}”.) control 160 DEG C～240 DEG C scope and film is heated.

If heat setting temperature is more than 160 DEG C, polyester molecule can be fixed by the easy crystallization of polyester with elongation state Change, it is possible to increase the hydrolytic resistance of polyester film.If additionally, heat setting temperature is less than 240 DEG C, due in polyester molecule each other The part being wound around mutually is not likely to produce slip, and polyester molecule is difficult to shrink, it is possible to the fall of the hydrolytic resistance of suppression polyester film Low.In other words, heated by way of reach 160 DEG C～240 DEG C according to heat setting temperature, polyester molecule can be made Crystallization is orientated, and improves the hydrolytic resistance of polyester film.

With regard to heat setting temperature, from above-mentioned same the reasons why, preferably 170 DEG C～230 DEG C of scope, more preferably 175 DEG C～225 DEG C of scope.

In addition, it is so that thermocouple is contacted the surface of polyester film 200 and measure that highest reaches film surface temperature (heat setting temperature) Value.

And then, heat setting temperature is controlled when 160 DEG C～240 DEG C, preferably the highest on film width is reached film Face temperature deviation is set to more than 0.5 DEG C and less than 10.0 DEG C.On film width, film surface temperature is reached by the highest making film Deviation is more than 0.5 DEG C, and during conveyance in rear operation, the aspect of gauffer is favourable, additionally, by deviation suppression exists Less than 10.0 DEG C, the deviation of the crystallization degree on width can be suppressed.Thus, the lax subtractive on film width is light, The generation of the damage on the face in manufacture process can be prevented, hydrolytic resistance improves.

In above-mentioned, with regard to highest reach film surface temperature deviation, from as described above the reasons why, more preferably 0.5 DEG C Above and less than 7.0 DEG C, more preferably more than 0.5 DEG C and less than 5.0 DEG C, particularly preferably more than 0.5 DEG C and 4.0 DEG C with Under.

Additionally, the heating to film during thermal finalization can only be carried out it is also possible to carry out from both sides from the side of film.For example, When being cooled down on curtain coating drum after melt extruding in film forming process, because the polyester film having shaped is in a face and its phase The face type of cooling tossed about is different, so film becomes easily to crimp.It is therefore preferable that contacting with curtain coating drum in film forming process Face carry out the heating in this heat-setting process.By by the heating surface in heat-setting process be set to be cast drum contact face, I.e. cooling surface, can eliminate curling.

Now, heating is preferably according to the surface temperature after the firm heating on the heating surface in heat-setting process and and heating surface The mode that the surface temperature of the non-heated of opposition side is compared more than 0.5 DEG C and less than 5.0 DEG C of scope uprises is carried out.Pass through Make the temperature of heating surface during thermal finalization higher than the face of its opposition side, and the temperature difference between its table back of the body is 0.5～5.0 DEG C, permissible More effectively eliminate the curling of film.From curling eradicating efficacy from the viewpoint of, the non-heated of the opposite to that side of heating surface it Between temperature difference more preferably 0.7～3.0 DEG C of scope, more preferably more than 0.8 DEG C and less than 2.0 DEG C.

Additionally, the TD direction in the present invention, at least one of thermal finalization portion 30 and hot wire-CVD portion 40, to polyester film End carries out selective radiation heating using heater.If not carrying out described radiant heating, the TD side of made polyester film MD percent thermal shrinkage upwards will not decline, and the variable quantity of the distribution of MD percent thermal shrinkage and MD percent thermal shrinkage will not diminish, so no Legal system makes the film meeting already described formula (I) and (II).

When radiant heating being carried out to the TD direction end of film in hot wire-CVD portion 40, it is convenient to omit the spoke in thermal finalization portion 30 Penetrate heating it is also possible to carry out in both thermal finalization portion 30 and hot wire-CVD portion 40.

Wherein, so-called " the TD direction end of polyester film " refer to polyester film the edge at the two ends in TD direction and from edge to Region till the 10% of the total length (i.e., width) in the TD direction of polyester film.

The heating of the TD direction end of polyester film is carried out using the heater being capable of radiant heating, the TD side to polyester film To at least one end carry out selectivity heating.From the viewpoint of the MD thermal contraction of suppression local, preferred pair polyester film The both ends in TD direction are heated.In addition, so-called " selectivity heating " not integrally enters to the film of the end comprising polyester film Row heating, and refer to film end is partly heated.

As the heater being capable of radiant heating, such as infrared heater can be included, particularly preferably using ceramic Heater (ceramic heater).

The heating of the TD direction end of polyester film preferably adjusts surface temperature and polyester film surface and the heater of heater Distance (air line distance) and carry out.

When the surface temperature of heater is 300 DEG C～800 DEG C, preferably the distance on polyester film surface and heater is set to 20mm～250mm, more preferably heater surface temperatures are 400 DEG C～700 DEG C and are set to the distance between film-heater 50mm～200mm.

Additionally, when carrying out radiant heating, preferably the temperature deviation on film TD direction is contracted to more than 0.7 DEG C and 3.0 Scope below DEG C, thus, it is possible to mitigate the deviation of the crystallization degree on film width to less than more than 0.5%～3.0% Scope.Like this, the increase and decrease of the local of MD percent thermal shrinkage can be suppressed, the generation of tendon shape protuberance can be suppressed, can simultaneously Enough raising hydrolytic resistances further.

When thermal finalization portion is heated, preferably the holdup time in thermal finalization portion be set to more than 5 seconds and 50 seconds with Under.The so-called holdup time is film heated state duration in thermal finalization portion.If the holdup time is more than 5 seconds, Because the crystallization degree with respect to heat time heating time diminishes, so the less susceptible generation of crystallization degree deviation in width Aspect be favourable, if less than 50 seconds in addition, then due to there is no need extremely to reduce the linear velocity of stenter, so giving birth to The aspect of yield is favourable.

Wherein, with regard to the holdup time, from above-mentioned same the reasons why, preferably more than 8 seconds and less than 40 seconds, more preferably 10 Second above and less than 30 seconds.

In the present invention, at least one of thermal finalization portion and hot wire-CVD portion, radiant heating is carried out to polyester film end, But the selectivity spoke of film end can also be carried out further in both preheating part or extension section or preheating part and extension section Penetrate heating.

It is temperature deviation and the crystallization on the TD direction mitigate film to the radiant heating of the TD direction end of polyester film The heating of the deviation of degree, becomes easily to suppress the increase and decrease of the local of MD percent thermal shrinkage.

(d. hot wire-CVD portion)

In hot wire-CVD portion, the tension recovery of polyester film is removed the remnants of striping by the polyester film heating through thermal finalization Strain.

As described above, in the manufacture method of the polyester film of the present invention, in thermal finalization portion and hot wire-CVD portion at least one In person, using heater, selective radiation heating is carried out to the TD direction end of polyester film.The TD of the polyester film in hot wire-CVD portion As long as direction end selective radiation heating by with thermal finalization portion in polyester film TD direction end selective radiation Heat same method to carry out, the numerical range of heating-up temperature and preferred mode are similarly.

However, hot wire-CVD is by the polyester film heating through thermal finalization and the tension force of lax polyester film, right in hot wire-CVD portion The heating of polyester film is preferably as follows and carries out.

In hot wire-CVD portion 40 shown in figure 3, preferably reach film surface temperature according to the highest on the surface of polyester film 200 and reach The highest of the polyester film 200 in specific heat setting section 30 reaches film surface temperature (T_{Thermal finalization}) low more than 5 DEG C temperature mode to poly- The mode that ester film 200 is heated.

Hereinafter, also the highest on the surface of the polyester film 200 during hot wire-CVD is reached film surface temperature and be referred to as " hot wire-CVD temperature (T_{Hot wire-CVD})”.

In hot wire-CVD portion 40, by making hot wire-CVD temperature (T_{Hot wire-CVD}) than heat setting temperature (T_{Thermal finalization}) low more than 5 DEG C of temperature Degree (T_{Hot wire-CVD}≤T_{Thermal finalization}- 5 DEG C) carry out heating to release tension force (reduction tensile stress), the chi of polyester film can be improved further Very little stability.

If T_{Hot wire-CVD}For " T_{Thermal finalization}- 5 DEG C " below, then the hydrolytic resistance of polyester film is more excellent.Additionally, T_{Hot wire-CVD}In dimensional stability The aspect becoming good is preferably more than 100 DEG C.

And then, T_{Hot wire-CVD}It is preferably more than 100 DEG C and compare T_{Thermal finalization}(100 DEG C≤T of low more than 15 DEG C of temperature province_{Hot wire-CVD}≤ T_{Thermal finalization}- 15 DEG C), more preferably more than 110 DEG C and compare T_{Thermal finalization}(110 DEG C≤T of low more than 25 DEG C of temperature province_{Hot wire-CVD}≤T_{Thermal finalization}-25 DEG C), particularly preferably more than 120 DEG C and compare T_{Thermal finalization}(120 DEG C≤T of low more than 30 DEG C of temperature province_{Hot wire-CVD}≤T_{Thermal finalization}-30℃).

In addition, T_{Hot wire-CVD}It is the value being measured by making the surface of thermocouple contact polyester film 200.

(e. cooling end)

In cooling end, by the polyester film cooling after hot wire-CVD in hot wire-CVD portion.

As shown in Figure 3, in cooling end 50, the polyester film 200 behind hot wire-CVD portion 40 is cooled down.Pass through Warmed-up polyester film 200 will cool down in thermal finalization portion 30 or hot wire-CVD portion 40, thus the shape of polyester film 200 is finalized Change.

The surface (face) of the polyester in cooling end exit of the polyester 200 in cooling end 50 temperature (hereinafter also referred to as " chilling temperature ".) preferably low than+50 DEG C of the glass transition temperature Tg of polyester film 200.Specifically, preferably 25 DEG C～110 DEG C, more preferably 25 DEG C～95 DEG C, more preferably 25 DEG C～80 DEG C.By making chilling temperature be above range, Neng Goufang Only release clip holding caudacoria unevenly to shrink.

Wherein, so-called cooling end outlet refers to the end of cooling end 50 when cooling end 50 leaves for the polyester 200, refers to handle The holding component 2 (in Fig. 3, holding component 2j and 2l) holding polyester film 200 leaves position during polyester film 200.

And then, in cooling end 50, preferably will make the temperature on the surface (face) of polyester film when being cooled to 70 DEG C for 150 DEG C Average cooling rate be set to 2 DEG C/sec～100 DEG C/sec of scope.

Wherein, average cooling rate is by using the film Wen Erqiu of the film in radiation thermometer actual measurement cooled region ?.That is, reached 150 DEG C of place by film temperature and the conveyance speed Sm/ second apart from Zm and film in place that film temperature reaches 70 DEG C is asked Go out (Z ÷ S) second cool time from 150 to 70 DEG C.By (150-70) ÷ (Z ÷ S) is calculated further by it, obtain averagely cold But speed.

By average cooling rate is set to more than 2 DEG C/sec, the cooling of polyester film in stretching device can be suppressed not Foot, the cohesive step-down of polyester film.Therefore, in the operation after leaving polyester film from cooling end outlet, become to be not likely to produce poly- Ester film be adhered to film conveyance roller on etc. fault.Additionally, by average cooling rate is set to less than 100 DEG C/sec, permissible Prevent the chilling of polyester film, be not likely to produce residual stress inequality in face, percent thermal shrinkage deviation can be suppressed, become to be difficult to produce Raw tendon shape protuberance.

More preferably 4 DEG C/sec～80 DEG C/sec of average cooling rate, more preferably 5 DEG C/sec～50 DEG C/sec.

But, in the manufacture method of the polyester film of the present invention, the average cooling rate of the film in cooling end is in film width Different in the central part of direction end and film width (TD direction).Specifically, will be average in film width end Rate of cooling is set to 1.01 times～2 times of the average cooling rate in the central part of film TD direction.Thus, reduce the trickle of polyester film MD percent thermal shrinkage variation, become easily to suppress the tendon shape of polyester film to swell.

By by the average cooling rate in film width end with respect to film TD direction central part average cooling The multiplying power (also referred to as specific circulating ratio) of speed is set to more than 1.01 times and less than 2 times, become easy to manufacture meet formula (I) and (II) relatively thin polyester film, the easily generation of suppression tendon shape protuberance.

Specific circulating ratio is preferably 1.03 times～1.7 times, more preferably 1.05 times～1.5 times.

In the preheating in cross directional stretch operation, stretching, thermal finalization, hot wire-CVD and cooling, add as by polyester film 200 Heat or the temperature-controlled process of cooling, can include and polyester film 200 is blowed with hot blast or cold wind, makes polyester film 200 and can control The surface contact of the metallic plate of temperature processed or the vicinity through metallic plate.

(recovery of film)

Polyester film 200 chilled in refrigerating work procedure is cut away the handle part gripping with clip at TD direction two ends Point, batched with roll.

In cross directional stretch operation, in order to improve hydrolytic resistance and the dimensional stability of manufactured polyester film further, The polyester film preferably carrying out by method below having stretched lax.

In the present invention, after longitudinal stretching operation, preferably carry out cross directional stretch operation, then carry out in cooling end 50 MD direction lax.That is,

In preheating part 10, an end is held using at least two holding components with the width (TD) of polyester film 200 Both ends.For example, with holding the side of an end of the width (TD) of component 2a and 2b holding polyester film 200, use Hold component 2c and 2d and hold opposite side.Then, moved by making holding component 2a～2d, by polyester film 200 from preheating part 10 Transport to cooling end 50.

In described conveyance, by with preheating part 10 in one of width (TD direction) of holding polyester film 200 Holding component 2a (2c) of end be adjacent to hold component 2a (2c) other hold component 2b (2d) interval compared with, constriction In cooling end 50 holding polyester film 200 holding component 2a (2c) of an end of width be adjacent to holding component The interval of other holdings component 2b (2d) of 2a (2c), thus reduce the conveyance speed of polyester film 200.By methods described, energy In cooling end 50, enough carry out the lax of MD direction.

The lax of the MD direction of polyester film 200 can be at least the one of thermal finalization portion 30, hot wire-CVD portion 40 and cooling end 50 Carry out in individual position.

As described above, by making interval between holding component 2a-2b and holding and be spaced in downstream between component 2c-2d Narrower than MD direction upstream side, can carry out polyester film 200 MD direction lax.Therefore, in thermal finalization portion 30 or hot wire-CVD portion Carry out in 40 MD direction lax in the case of, as long as reaching thermal finalization portion 30 or hot wire-CVD portion 40 holding component 2a～2d When, slow down the translational speed holding component 2a～2d, reduce the conveyance speed of polyester film 200, between making between holding component 2a-2b Every and hold component 2c-2d between interval narrower than the interval in preheating part.

Preferably the conveyance speed of polyester film and the width (total length in the TD direction of film) of polyester film meet lower relation of plane.

That is, preferably laterally the width of the polyester film in stretching process reaches width L1 and the polyester film of polyester film during maximum The width L2 of the polyester film from the end of the cooling end that cooling end leaves meets following formula (1), and, the polyester in preheating part Conveyance speed S2 of the polyester film in conveyance speed S1 of film and the end of cooling end meets following formula (2).

[mathematical expression 2]

Meet the relation shown in formula (1) and (2) by making the conveyance speed of polyester film and the width of polyester film, become easy Reduce the absolute value of the made percent thermal shrinkage in MD direction of polyester film, accompany with this, dividing of MD percent thermal shrinkage can be reduced Cloth and the variation of MD percent thermal shrinkage.

Wherein, so-called " width of the polyester film in cross directional stretch operation reaches the width L1 of polyester film during maximum " is poly- Ester film in extension section along TD direction broadening after polyester film TD direction maximum length.

Shown in Fig. 3, the width L0 of the polyester film 200 before the stretching in preheating part 10 because using extension section 20 by polyester film 200 become width L1 along the broadening of TD direction, release tension force, leave from cooling end 50 in polyester film 200 in hot wire-CVD portion 40 Shi Biancheng width L2.In Fig. 3, the order width according to L0 ＜ L2 ＜ L1 becomes big.That is, L1 is the horizontal stroke of preheating part 10～cooling end 50 Width to the maximum of the polyester film 200 in stretching process.

As shown in Figure 3, because the polyester film 200 behind stretched portion 20 is being applied thereafter in thermal finalization portion 30 Plus it is heated, so bandpass L1 is referred to as the width (TD of the polyester film 200 in thermal finalization portion 30 in the state of tension force The length in direction).

Additionally, " the width L2 of the polyester film in the end of the cooling end that polyester film leaves " is in cooling end and holds The holding component (being to hold component 2j and 2l in Fig. 3) of polyester film leaves the width of polyester film during polyester film.

Holding component because holding polyester film leaves polyester film, and polyester film leaves from the region of cooling end.For example, in Fig. 3 Shown in holding component 2j P point, in addition hold component 2l in Q point respectively away from polyester film 200 when, the end of cooling end 50 (end in MD direction) is represented by the straight line linking P point and Q point.

" conveyance speed S1 of the polyester film in preheating part " is equivalent to holding polyester film and moves along the edge of annular orbit Holding component (in Fig. 3 be 2a～2d) translational speed.

Additionally, " conveyance speed S2 of the polyester film in the above-mentioned end of cooling end " is in cooling end and holds polyester The holding component (being to hold component 2j and 2l in Fig. 3) of film leaves the conveyance speed of polyester film during polyester film.Using Fig. 3, if In other words, then for example hold component 2j P point, in addition hold component 2l in Q point respectively away from polyester film 200 when, " cooling Conveyance speed S2 of the polyester film 200 in the above-mentioned end in portion 50 " is equivalent to polyester film 200 and exceedes the straight line linking P point and Q point When conveyance speed.If further in other words, " conveyance speed S2 of the polyester film 200 in the above-mentioned end of cooling end 50 " phase Translational speed as holding component 2j and 2l before holding component 2j and 2l and will leaving polyester film 200.

Formula (1) means after stretching polyester film 200, along TD direction relax when, preferably according to the maximum of polyester film 200 Width (length in TD direction) L1 shrink 2%～15% mode in cooling end 50 and relaxed.

Formula (2) means when polyester film 200 relaxes along MD direction, preferably according in the preheating part 10 of polyester film 200 Slow down in cooling end 50 2%～15% mode of conveyance speed S1 relaxed.

By cross directional stretch operation is set to above-mentioned composition, become easily to suppress the tendon shape of polyester film to swell.

[mathematical expression 3]

Because Δ L represents the relaxation rate in the TD direction (horizontal) of polyester film, so also Δ L is referred to as " TD relaxation rate ".This Outward, because Δ S represents the relaxation rate in the MD direction (longitudinal) of polyester film, so also Δ S is referred to as " MD relaxation rate ".

As shown in formula (1) and (2), Δ L and Δ S be both preferably 2%～15% (2%≤Δ L≤15%, 2% ≤ Δ S≤15%).

Be more than 2% by making Δ L and Δ S, manufactured relatively thin polyester film become to readily satisfy formula (I) and (II), become easily to suppress tendon shape to swell.It is less than 15% by making Δ L and Δ S, polyester film is easily received in stretching device Contracting, can suppress lax.

Δ L more preferably 2%～10% (2%≤Δ L≤10%), more preferably 3%～8% (3%≤Δ L≤ 8%).Additionally, Δ S is more preferably 2%～10% (2%≤Δ S≤10%), more preferably 3%～8% (3%≤Δ S ≤ 8%).

The relatively thin film that the polyester film of the present invention and thickness reach less than 100 μm is unrelated, even if heated conveyance is not easy to Producing tendon shape protuberance, even if pasting coating fluid or functional component sheet material etc. on film, being not easy to produce crawling, sheet material patch Bubble during conjunction such as is mixed at the fault.Therefore, it can in the various uses processed for carrying out heating conveyance or shape.

Optical film, electric insulation film for example can be suitable for.

In addition it is also possible to the polyester film of the present invention is used as the film of solar module.In this case, too As long as sun can battery module for example be constituted as follows.

Solar module typically the incident transparency of sunlight substrate and the already described present invention polyester film (too Sun can battery backboard) between configure and the luminous energy of sunlight is converted into the solar cell device of electric energy and constitutes.As tool The embodiment of body is it is also possible to be configured in the following manner：Generating element (the sun that will be connected with the lead (not shown) taking out electricity Energy cell device) sealed with sealants such as ethylene vinyl acetate copolymer system (EVA system) resins, and sandwiched glass etc. Paste and constitute between the polyester film (backboard) of transparency carrier and the present invention and each other.

As the example of solar cell device, can apply the silicon systems such as monocrystal silicon, polysilicon, amorphous silicon, copper-indium- The various known solar energy such as iii-v or II-VI group group compound semiconductor system such as gallium-selenium, copper-indium-selenium, cadmium-tellurium, gallium-arsenic Cell device.Resin (the so-called sealing material such as such as ethylene-vinyl acetate copolymer can be used between substrate and polyester film Material) seal and constitute.

Embodiment

Hereinafter, by embodiment, the present invention is more specifically illustrated, but the present invention is without departing from its purport, not It is defined in below example.In addition, unless otherwise specified, " part " is quality criteria.

(polyester feed stock resin 1)

As shown below, using making p-phthalic acid and ethylene glycol direct reaction and water being distilled off, carry out After esterification, carry out the direct esterification of polycondensation under reduced pressure, obtain polyester (Ti catalyst system PET) using continuous polymerization unit.

(1) esterification

In the first esterification groove, by 4.7 tons of high purity terephthalic acid and the mixing in 90 minutes of 1.8 tons of use of ethylene glycol Form slurry, be continuously fed in the first esterification groove with the flow of 3800kg/h.Continuously feed citric acid further Chelate the ethylene glycol of titanium complex (VERTEC AC-420, Johnson Matthey company system) with the citric acid of Ti metal-complexing Solution, in reactive tank 250 DEG C of temperature, stirring under, reacted within about 4.3 hours with mean residence time.Now, citric acid chela Close titanium complex continuously to add according to the mode that Ti addition reaches 9ppm in terms of element scaled value.Now, obtained low The acid number of polymers is 600 equivalents/ton.In addition, in this specification, " equivalent/t " represents every 1 ton of molar equivalent.

This product is transplanted in the second esterification groove, under agitation, at 250 DEG C of temperature in reactive tank, with flat All holdup time meter reactions 1.2 hours, obtain the oligomer that acid number is 200 equivalents/ton.The interior part of the second esterification groove every Become 3 regions, continuously feed magnesium acetate from the 2nd region according to the mode that Mg addition reaches 75ppm in terms of element scaled value Ethylene glycol solution, then continuously feed according to the mode that P addition reaches 65ppm in terms of element scaled value from the 3rd region The ethylene glycol solution of trimethyl phosphate.

(2) polycondensation reaction

Esterification reaction product obtained above is continuously fed in the first polycondensation reaction groove, under agitation, reacts temperature Pressure 20torr (2.67 × 10 in 270 DEG C of degree, reactive tank^-3MPa, under), its polycondensation is made in about 1.8 hours with mean residence time.

And then, be transplanted in the second polycondensation reaction groove, in this reactive tank, under agitation, 276 DEG C of temperature in reactive tank, Pressure 5torr (6.67 × 10 in reactive tank^-4MPa under), the condition of about 1.2 hours holdup times make it react (polycondensation).

Then, it is transplanted on further in the 3rd polycondensation reaction groove, in this reactive tank, 278 DEG C of temperature, anti-in reactive tank Answer pressure 1.5torr (2.0 × 10 in groove^-4MPa), make it react (polycondensation) under conditions of 1.5 hours holdup times, reacted Product (polyethylene terephthalate (PET)).

Then, obtained product is ejected in cold water with strand shape, cuts immediately and make the granule of polyester< Section：Major diameter is about 4mm, minor axis is about 2mm, length：It is about 3mm>.

For obtained polyester, analyze (HR-ICP- using high-resolution type high-frequency inductive coupling plasma weight MS；SII Nanotechnology Inc. AttoM) as shown below as be measured, result Ti=9ppm, Mg= 75ppm, P=60ppm.P slightly reduces with respect to addition originally, and presumption produces volatilization in the course of the polymerization process.

Obtained polymer is IV=0.67, amount (the AV)=23 equivalents/ton of terminal carboxyl group, fusing point=257 DEG C, solution Mist degree=0.3%.The mensure of IV and AV is carried out by method shown below.

The mensure of～IV and AV～

Intrinsic viscosity (IV) with regard to polyester feed stock resin, by polyester feed stock resin be dissolved into sym.-tetrachloroethane/ In phenol (=2/3 [mass ratio]) mixed solvent, obtained by the solution viscosity at 25 DEG C in this mixed solvent.

End COOH with regard to polyester feed stock resin measures (AV), and non-stretched polyester film 1 is completely dissolved in benzyl alcohol/chloroform (=2/3；Volume ratio) mixed solution in, be used phenol red as indicator, with titer, (0.025N KOH- methanol mixed is molten Liquid) titrated, calculated by its titer.

Operate as described above, synthesized polyester feed stock resin 1.

(polyester feed stock resin 2)

By batch process, solid phase is implemented to polyester feed stock resin 1.That is, after the granule of polyester being put in container, side Being set as vacuum and stir, while carrying out Pre-crystallizing process at 150 DEG C, carrying out the solid phase of 30 hours afterwards at 190 DEG C Reaction.

Operate as described above, synthesized polyester feed stock resin 2.

(polyester feed stock resin 3)

Using 97.6 parts of 2, the 6- naphthalene dicarboxylic acids dimethyl ester (100 moles of %) as binary acid and the ethylene glycol as dihydroxylic alcohols 49.6 parts (100 moles of %) put in ester exchange groove, so that it is heated up while methanol is distilled off when carrying out ester exchange reaction, When methanol distillates to theoretical amount, product is transferred in polycondensation groove, adds the germanium oxide as polycondensation catalyst After 0.016 part, it is heated to 290 DEG C when being decompressed to fine vacuum and ethylene glycol is distilled off.Just reach target in stirring moment of torsion Terminate during value to react, obtained polymer is taken out with the strand shape of diameter 2.5mm in water.By obtained strand shape Polymer microtome cuts into flake.The intrinsic viscosity (IV) of obtained polymer is 0.60.

Operate as described above, obtain the polyester feed stock resin 3 of poly- NDA glycol ester (PEN).

(polyester feed stock resin 4)

With reference to the paragraph [0107] (embodiment 1) of Japanese Unexamined Patent Publication 2009-149066 publication, prepare polyester raw material tree Fat 4.

(embodiment 1)

- film forming process-

Polyester feed stock resin 1 is dried to knead for the single shaft after below 20ppm, putting into a diameter of 50mm to moisture content and squeezes Go out in the hopper of machine.Polyester feed stock resin 1 melts at 300 DEG C, by following extrusion conditions, via gear pump, filter (hole Footpath is 20 μm), from mould extrusion.In addition, adjust the size of the slit of mould according to the mode that the thickness of polyester sheet reaches 0.6mm. The automatic thickness meter that the thickness of polyester sheet passes through to be arranged at the outlet of curtain coating drum is measured.

Now, the Temperature Distribution that the extrusion of molten resin is set to 1%, molten resin in pressure oscillation is set to 2% condition Under carry out.Specifically, the back pressure in the cylinder of extruder is set to high with respect to average pressure in the cylinder of extruder 1% Pressure, the pipe arrangement temperature of extruder is set to high with respect to mean temperature in the cylinder of extruder 2% temperature and is heated. When extruding from mould, molten resin is expressed on the curtain coating drum of cooling, applies method using electrostatic and adhere on curtain coating drum.Close In the cooling of molten resin, the temperature of curtain coating drum is set as 25 DEG C, fills from the cold wind being oppositely arranged with curtain coating drum simultaneously Put the cold wind of 25 DEG C of blowout and blow and fuse melt resin.Using the angle stripper with curtain coating drum relative configuration, from curtain coating drum, thickness is 0.6mm, film width are that the non-stretched polyester film (non-stretched polyester film 1) of 0.9m is peeled off.

The intrinsic viscosity IV=0.64dL/g of obtained non-stretched polyester film 1, terminal carboxyl group amount (AV)=25 equivalent/ Ton, glass transition temperature (Tg)=72 DEG C.

The mensure of～IV and AV～

Intrinsic viscosity (IV) with regard to non-stretched polyester film, by non-stretched polyester film be dissolved into sym.-tetrachloroethane/ In phenol (=2/3 [mass ratio]) mixed solvent, obtained by the solution viscosity at 25 DEG C in this mixed solvent.

End COOH with regard to non-stretched polyester film measures (AV), and non-stretched polyester film is completely dissolved in benzyl alcohol/chloroform (=2/3；Volume ratio) mixed solution in, be used phenol red as indicator, with titer, (0.025N KOH- methanol mixed is molten Liquid) titrated, calculated by its titer.

For obtained non-stretched polyester film 1, stretched by carrying out gradually biaxial stretch-formed with following method, make Thickness is 50 μm, film width (total length in TD direction) is the biaxially oriented polyester film 1 of 2.5m.

- longitudinal stretching operation-

Non-stretched polyester film 1 is passed through, between 2 pairs of different niprolls of peripheral speed, (to remove along longitudinal under the following conditions Send direction) stretched.

Preheating temperature：80℃

Longitudinal drawing temperature：90℃

Longitudinal stretching multiplying power：3.5 again

Longitudinal stretching stress：12MPa

- cross directional stretch operation-

For the polyester film 1 (longitudinal stretching polyester film 1) through longitudinal stretching, using having drawing of the structure shown in Fig. 3 Width machine (biaxial stretcher), is stretched with following methods, condition.

(preheating part)

Preheating temperature is set to 110 DEG C, heating enables to stretch.

(extension section)

By the longitudinal stretching polyester film 1 after preheating along the vertical film width in the direction (length direction) with longitudinal stretching (TD direction) applies tension force under conditions of following, carries out cross directional stretch.

Draft temperature (transverse drawing temperature)：125℃

Stretching ratio (cross directional stretch multiplying power)：4.2 again

Tensile stress (lateral tensile stress)：18MPa

(thermal finalization portion)

Then, highest arrival film surface temperature (heat setting temperature) of polyester film is controlled and is heated in following ranges, Make its crystallization.

Highest reaches film surface temperature (heat setting temperature T_{Thermal finalization})：220〔℃〕

Heat setting temperature T therein_{Thermal finalization}Pre- peak temperature (DEG C) for DSC.

Additionally, the curtain coating face contacting is roused by film forming process with curtain coating to the both ends of film width (TD direction) Infrared heater (the heater surface temperatures by ceramic for the side：650 DEG C) carry out radiant heating.Now, heater with poly- The distance of ester film is set to 170mm.

(hot wire-CVD portion)

Polyester film after thermal finalization is heated to following temperature, by the tension recovery of film.Now, to film width Infrared heater (heater surface temperatures are passed through by curtain coating surface side in the same manner as thermal finalization in both ends：350 DEG C) radiated Heating.

Hot wire-CVD temperature (T_{Hot wire-CVD})：150℃

Hot wire-CVD rate：TD direction (TD hot wire-CVD rate；Δ L)=5%

MD direction (MD hot wire-CVD rate；Δ S)=5%

(cooling end)

Then, the polyester film after hot wire-CVD is cooled down under 65 DEG C of chilling temperature.

Now, average cooling rate is set to 40 DEG C/sec, the average cooling rate in film width end is relative The multiplying power (being expressed as " end/central part " in specific circulating ratio, table 1) of the average cooling rate in the central part of film TD direction It is set to 1.1 times.

- recovery of film-

After cooling is complete, every for the two ends of polyester film 20cm is pruned.Afterwards, squeezed with width 10mm at two ends After going out processing (embossing), batched with tension force 25kg/m.

Operate as described above, made the biaxially oriented polyester film (PET film) that thickness is 50 μm.

- A. evaluation of measuring-

Following mensure, evaluation are carried out to the biaxially oriented polyester film of above-mentioned making.The result measure, evaluated is shown in following In table 1.

(1) the MD percent thermal shrinkage on TD direction and MD percent thermal shrinkage are uneven

Biaxially oriented polyester film is cut, makes coupons M of the size of TD direction 30mm, MD direction 120mm.For examination Print M, according to the mode at the interval reaching 100mm in the MD direction, draws 2 foundation directrixes, in 150 DEG C of heating under no-station pole canopy Place 30 minutes in baking oven.After this placement, coupons M are cooled to room temperature, measure the interval of 2 foundation directrixes, by this value It is set to A (unit；mm).Using the numerical value being calculated by the formula of the A being measured and " 100 × (100-A)/100 " as MD percent thermal shrinkage (Sh).

To film from the end in TD direction to another end, every 50mm is (with the TD direction of each coupons M Central point interval meter 50mm interval) measure described MD percent thermal shrinkage, calculate the numerical value of maximum of MD percent thermal shrinkage and minimum number The difference of value is as MD percent thermal shrinkage deviation (Δ Sh).In addition, would indicate that the schematic diagram of the method measuring MD percent thermal shrinkage in Fig. 4 In.

(2) MD percent thermal shrinkage variable quantity x [%/m] absolute value of the per unit distance in film TD direction maximum X [%/ M] and x the rate of change y absolute value of per unit distance maximum Y [%/m²] mensure

X is that on TD direction, every 0.05m measures MD percent thermal shrinkage (150 DEG C and 30 minutes) to biaxially oriented polyester film, leads to Cross what following formula calculated.

X=(the MD percent thermal shrinkage adjoining in arbitrary position is poor) ÷ 0.05m

In addition, x can also take negative value.

X is the maximum on the width of the x absolute value being calculated.

Y due to the rate of change of the per unit distance for x, so being calculated by following formula.

Y=(difference of the x between the measuring point that arbitrary position adjoins) ÷ 0.05m

In addition, y can also take negative value.

Y is the maximum on the width of y absolute value.

(3) mensure of thickness

The thickness of obtained biaxially oriented polyester film is tried to achieve as follows.

For biaxially oriented polyester film, using contact film thickness measuring meter (ANRITSU company system), in the side of longitudinal stretching To on (length direction) to whole 0.5m with 50 points of periodic sampling, (vertical with length direction in film width further Direction) on to film overall with (50 decile in the width direction) at equal intervals sample 50 points after, measure this 100 points of thickness.Obtain this 100 points of average thickness, as the thickness of polyester film.

(4) DSC pre- peak temperature deviation (Δ Tpp)

For obtained biaxially oriented polyester film, complete to another end from an end in TD direction to film Width, equably samples at 11 points, measures the pre- peak temperature of DSC (Tpp).By the maxima and minima of the multiple Tpp values being measured Difference (Δ Tpp) is as DSC pre- peak temperature deviation.

In addition, the pre- peak temperature of DSC is that the film of the coupons being sampled is placed ormal weight (2～10mg) to Co., Ltd. island Tianjin makes in made DSC-60, is warming up to 300 DEG C with the programming rate of 10 DEG C/min and is measured.Read in polyester (PET) peak temperature of the endothermic peak occurring in front of melting hump is as the pre- peak temperature of DSC (Tpp).

(5) tendon shape protuberance judges

For obtained biaxially oriented polyester film, observe the degree of the tendon shape protuberance of face by visual observation, according to following Metewand evaluated.

AA：Substantially do not see the generation of tendon shape protuberance.

A：Somewhat see the generation of tendon shape protuberance, but face is good.

B：See the generation of tendon shape protuberance, but for the degree of obstacle is not had on practicality.

C：Significantly see the generation of tendon shape protuberance.

(embodiment 2～embodiment 9 and comparative example 1～comparative example 4)

In embodiment 1, in addition to the condition shown in list of modification 1, all similarly operate, obtain embodiment 2～reality Apply example 9 and the biaxially oriented polyester film of comparative example 1～comparative example 4.

Additionally, for obtained biaxially oriented polyester film, by the side same with the biaxially oriented polyester film of embodiment 1 Method, carries out the evaluation of physical property of biaxially oriented polyester film and tendon shape protuberance is evaluated.Show the result in table 1.

(comparative example 5)

According to the embodiment 1 of Japanese Unexamined Patent Publication 2009-149066 publication, obtain biaxially oriented polyester film.

For obtained biaxially oriented polyester film, by the method same with the biaxially oriented polyester film of embodiment 1, enter The evaluation of physical property of row biaxially oriented polyester film and tendon shape protuberance are evaluated.Show the result in table 1.

[table 1]

As shown in table 1, in embodiment, in the contrast with comparative example, less inhibit tendon shape protuberance Produce.

The disclosure of Japanese patent application 2013-069479 filed in 28 days March in 2013 its entirely through with reference to quilt Include in this specification.Whole documents described in this specification, patent application and technical standard are recorded respectively with specifically and respectively Individual document, patent application and technical standard are by referring to situation about including to same extent by referring to including in this specification. Above record with regard to the embodiment illustrated of the present invention is in order at illustration and descriptive purpose and carries out, and is not intended to Enlist the services of or be defined in open invention mode itself.Obviously, many changes or change are not say for those skilled in the art And explain.Above-mentioned embodiment be best described by invent principle and practicality application, be suitable to imaginary specific purposes that The various embodiments of sample or various changes are skilled artisans appreciate that inventing and selecting, remember together in order to other Carry.It is intended that the scope of the present invention to be specified by claims below and its equipollent.

Symbol description

2a～2l ... holds component

10 ... preheating parts

20 ... extension sections

30 ... thermal finalization portions

40 ... hot wire-CVD portions

50 ... cooling ends

60 ... annular orbits

100 ... biaxial stretcher

200 ... polyester films

Claims

1. a kind of polyester film, its thickness is less than 100 μm,

Following maximum X and maximum Y meets following formula (I) and (II),

Described maximum X is to hang down with described film width in film width, described film width per unit distance Nogata to percent thermal shrinkage variable quantity x [%/m] absolute value maximum X [%/m],

Described maximum Y is the maximum Y of the rate of change y absolute value with respect to film width per unit distance of described x [%/m²],

0.01 ＜ X ＜ 2.00 ... (I)

0.1 ＜ Y ＜ 20.0 ... (II).

2. polyester film according to claim 1, wherein,

The percent thermal shrinkage of described film width central part and described film width vertical direction be more than 0.01% and Less than 3%.

3. polyester film according to claim 1, wherein,

The percent thermal shrinkage deviation of described film width and described film width vertical direction be more than 0.01% and Less than 0.5%.

4. polyester film according to claim 1, wherein,

It is more than 0.5 DEG C in described film width by the pre- peak temperature deviation that means of differential scanning calorimetry mensure is DSC mensure And less than 10 DEG C.

5. polyester film according to claim 1, wherein,

The intrinsic viscosity of polyester film is more than 0.55dL/g and below 0.90dL/g.

6. polyester film according to claim 1, wherein,

The amount of the terminal carboxyl group of polyester film is below more than 5eq/ ton and 35eq/ ton.

7. polyester film according to claim 1, wherein,

The containing ratio of the Component units of the polyfunctional monomer more than 3 senses is with respect to whole structures of the polyester in polyester film One-tenth unit is 0.005 mole of more than % and 2.5 mole of below %.

8. polyester film according to claim 1, wherein,

The percent thermal shrinkage of described film width central part and described film width vertical direction be more than 0.01% and Less than 3%,

The percent thermal shrinkage deviation of described film width and described film width vertical direction be more than 0.01% and Less than 0.5%,

It is more than 0.5 DEG C in described film width by the pre- peak temperature deviation that means of differential scanning calorimetry mensure is DSC mensure And less than 10 DEG C,

The intrinsic viscosity of polyester film is more than 0.55dL/g and below 0.90dL/g,

9. the manufacture method of the polyester film any one of a kind of claim 1～8, it includes：

Film forming process, polyester feed stock resin is melt extruded slabbing, cools down on curtain coating drum, so that polyester film is shaped；

Longitudinal stretching operation, the described polyester film after shaping is carried out longitudinal stretching along its length；And

Cross directional stretch operation, described polyester film is transported to following portion successively, by the polyester film after described longitudinal stretching Carry out cross directional stretch along the width vertical with described length direction, wherein said each portion is：After described longitudinal stretching Polyester film is preheated to the preheating part of the temperature that can stretch；Will be vertical with described length direction for the described polyester film edge after preheating Width applies tension force and carries out the extension section of cross directional stretch；To the institute carrying out after described longitudinal stretching and described cross directional stretch State polyester film to carry out heating the thermal finalization portion making its crystallization and thermal finalization；Polyester film after described thermal finalization is carried out heat, The tension recovery of polyester film is come the hot wire-CVD portion of the overstrain except striping；And the polyester film cooling after hot wire-CVD is cold But portion,

End profit at least one of described thermal finalization portion and described hot wire-CVD portion, to the polyester film of described width Carry out selective radiation heating with heater, and, in described cooling end, will be cold from 150 DEG C for the surface temperature making polyester film But to film width end when 70 DEG C average cooling rate be set to film width central part average cooling rate 1.01 times～2 times.

10. the manufacture method of polyester film according to claim 9, wherein,

Described radiant heating is carried out using ceramic heater.

The manufacture method of 11. polyester films according to claim 9, wherein,

The width of polyester film described in described cross directional stretch operation reaches the width L1 of described polyester film during maximum and described polyester The width L2 of the described polyester film of the end of described cooling end when described cooling end leaves for the film meets following formula (1), and,

Described in the described end with described cooling end for conveyance speed S1 of polyester film described in described preheating part, polyester film removes Speed S2 is sent to meet following formula (2),

0.02 \leq \frac{L 1 - L 2}{L 1} \leq 0.15 - - - (1)

0.02 \leq \frac{S 1 - S 2}{S 1} \leq 0.15 - - - (2) .

The manufacture method of 12. polyester films according to claim 9, wherein,

Described cross directional stretch operation use described below biaxial stretch-formed device, this biaxial stretch-formed device have described preheating part, Described extension section, described thermal finalization portion, described hot wire-CVD portion and described cooling end, and in described preheating part for an end Hold the both ends of the width of described polyester film using at least two holding components, by described polyester film from described preheating Portion transports to described cooling end,

By with described preheating part in hold the described holding component of described one end of polyester film width and be adjacent to this The interval holding the holding component of component is compared, and holds described one end of polyester film width in cooling end described in constriction The described interval holding between component holding component and being adjacent to this holding component, thus reduce the conveyance speed of described polyester film Degree.

The manufacture method of 13. polyester films according to claim 9, wherein,

In described cooling end, it is set to 2 by making the surface temperature of polyester film average cooling rate when being cooled to 70 DEG C for 150 DEG C DEG C/sec～100 DEG C/sec of scope.

The manufacture method of 14. polyester films according to claim 9, wherein,

Described radiant heating is carried out using ceramic heater,

0.02 \leq \frac{L 1 - L 2}{L 1} \leq 0.15 - - - (1)

0.02 \leq \frac{S 1 - S 2}{S 1} \leq 0.15 - - - (2),

By with described preheating part in hold the described holding component of described one end of polyester film width and be adjacent to this The interval holding the holding component of component is compared, and holds described one end of polyester film width in cooling end described in constriction The described interval holding between component holding component and being adjacent to this holding component, thus reduce the conveyance speed of described polyester film Degree,

The manufacture method of 15. polyester films according to claim 9, wherein,

Described radiant heating is carried out using ceramic heater,

0.02 \leq \frac{L 1 - L 2}{L 1} \leq 0.15 - - - (1)

0.02 \leq \frac{S 1 - S 2}{S 1} \leq 0.15 - - - (2)