JPH08134194A - Polyethylene naphthalate copolymer film - Google Patents

Abstract

PURPOSE: To obtain the subject film comprising a polyethylene naphthalate copolymer containing a naphthalene dicarboxylic acid and a tetralin dicarboxylic acid as main acid components, excellent in transparency, color tone, delamination resistance, etc., and especially useful as a substrate for photographic light- sensitive films. CONSTITUTION: This film comprises a polyethylene naphthalate copolymer containing (A) a naphthalene dicarboxylic acid preferably in an amount of 80-99.5mol.% and (B) a tetralin dicarboxylic acid preferably in an amount of 0.5-20mol.% as the acid components, and preferably has a film haze of <=2.0% and a yellow index (YID) of <=4. The components A and B are preferably 2,6- naphthalene dicarboxylic acid and 2,6-tetralin dicarboxylic acid, respectively.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a copolymerized polyethylene naphthalate film, and more specifically, it has excellent transparency,
The present invention relates to a copolymerized polyethylene naphthalate film having both hue, delamination resistance and curl curl resistance, which is particularly useful as a base film for photographic light-sensitive materials.

[0002]

2. Description of the Related Art As a base film (base film) used for a photographic light-sensitive material, a triacetate film has been widely used. Since this triacetate film uses an organic solvent in its manufacturing process, it has safety and environmental problems. In addition, there are problems such as limited mechanical strength and dimensional stability.

For this reason, polyethylene terephthalate film has come to be partially used as an alternative material. However, since curling curl remains strongly, handleability after development processing is poor and its range of use is limited. There is.

Therefore, in JP-A-53-146773, JP-A-1-244446 and the like, a modified polyethylene terephthalate film has been proposed which has an improved water vapor permeability and an improved water content. However, although these are effective in terms of reducing curling curl, they have drawbacks such as deterioration of dimensional stability due to moisture absorption and increase in deformation of the film end surface portion due to decrease in glass transition temperature. It was a thing.

In particular, in recent years, the use of photographic light-sensitive materials has been diversified, and the speed of transporting the film at the time of shooting has been increased and the size of the photographic device has been reduced, and it is excellent as a film for photographic light-sensitive materials. In addition to curl elimination, performance such as strength, dimensional stability and adaptability for thinning is required. Both the triacetate film and the modified polyethylene terephthalate film cannot sufficiently meet this demand, and a film for a photographic light-sensitive material having excellent properties is desired.

[0006]

SUMMARY OF THE INVENTION An object of the present invention is to provide a copolymerized polyethylene naphthalate which has excellent transparency, hue, delamination resistance and curl curl resistance and is particularly useful as a base film for photographic light-sensitive materials. To provide a film.

[0007]

The object of the present invention is to:
According to the present invention, a copolymer polyethylene naphthalate film is characterized in that the main acid components of the copolymer polyethylene naphthalate are naphthalenedicarboxylic acid and tetralindicarboxylic acid. Achieved by

In the present invention, the copolymerized polyethylene naphthalate is a copolymerized polyethylene naphthalate containing naphthalenedicarboxylic acid and tetralindicarboxylic acid as main acid components and ethylene glycol as a main glycol component.

Examples of the naphthalenedicarboxylic acid include 2,6-naphthalenedicarboxylic acid, 2,7-naphthalenedicarboxylic acid, and 1,5-naphthalenedicarboxylic acid. Of these, 2,6-
Naphthalenedicarboxylic acid is preferred. When the main acid component does not contain naphthalenedicarboxylic acid, for example, the curling curl when molded into a film becomes poor, which is not preferable.

This tetralindicarboxylic acid is obtained, for example, by hydrogenating naphthalenedicarboxylic acid using a platinum catalyst. For example, 2,6-tetralindicarboxylic acid, 2,7-tetralindicarboxylic acid, 1,
Although 5-tetralindicarboxylic acid and the like can be mentioned, among these, 2,6-tetralindicarboxylic acid is particularly preferable.

In the present invention, the main acid components constituting the copolymerized polyethylene naphthalate film are preferably 80 to 99.5 mol% of naphthalenedicarboxylic acid and 0.5 to 20 mol% of tetralindicarboxylic acid.

When the content of tetralindicarboxylic acid, which is a copolymerization component, is less than 0.5 mol% of all the acid components, the absorption of light in the low wavelength region due to the naphthalene ring becomes large, so that the yellow color of a film is obtained. The taste became stronger, and the yellow index (Y _ID ) of the film exceeded 4,
Further, the delamination resistance is deteriorated, which is not preferable. On the other hand, when the content of tetralindicarboxylic acid exceeds 20 mol% of all the acid components, the curl recovery rate of the film becomes poor, which is not preferable.

In the present invention, the copolymerized polyethylene naphthalate may be copolymerized with a small proportion of an acid component (other acid component) other than naphthalenedicarboxylic acid and tetralindicarboxylic acid, as long as the effects of the present invention are not impaired.

Other acid components include aromatic dicarboxylic acids (eg, terephthalic acid, isophthalic acid, diphenylethanedicarboxylic acid, diphenyldicarboxylic acid, diphenyletherdicarboxylic acid, diphenylsulfonedicarboxylic acid, diphenylketonedicarboxylic acid, anthracenedicarboxylic acid, etc. ); Aliphatic dicarboxylic acids (eg, adipic acid, sebacic acid, etc.); Alicyclic dicarboxylic acids (eg, cyclohexane-1,4-dicarboxylic acid, etc.) and the like.

As the glycol component other than ethylene glycol constituting the copolymerized polyethylene naphthalate,
Aliphatic glycols (eg trimethylene glycol, tetramethylene glycol, pentamethylene glycol,
Hexamethylene glycol, decamethylene glycol, and other polymethylene glycols having 3 to 10 carbon atoms, cyclohexanedimethanol, etc .; Aromatic diols (eg, hydroquinone, resorcin, 2,2-bis (4-hydroxyphenyl) propane, etc.); Examples thereof include polyalkylene glycol (polyoxyalkylene glycol) (eg, polyethylene glycol, polypropylene glycol, polytetramethylene glycol, etc.). The proportion of these other glycol components is preferably 10 mol% or less based on the total glycol components.

The copolymerized polyethylene naphthalate according to the present invention may be used as long as the effects of the present invention are not impaired.
Aromatic oxyacids such as hydroxybenzoic acid, ω-
A component derived from an oxycarboxylic acid such as an aliphatic oxyacid such as hydroxycaproic acid can also be copolymerized or bonded with 10 mol% or less based on the total amount of the dicarboxylic acid component and the oxycarboxylic acid component.

Further, in the copolymerized polyethylene naphthalate of the present invention, the amount is in the range of being substantially linear and unless the effects of the present invention are impaired, for example, 2 mol% or less based on the total acid component. It is also possible to copolymerize a trifunctional or higher functional polycarboxylic acid or polyhydroxy compound such as trimellitic acid or pentaerythritol in an amount.

Further, the copolymerized polyethylene naphthalate in the present invention includes, for example, a lubricant, a pigment, a dye, an antioxidant, a light stabilizer and a light-shielding agent (for example, as long as the surface flatness and the thermal stability are not impaired). Additives such as silica, cross-linked polystyrene, terazol blue, irganox, cobalt, etc.) can be contained if necessary.

As a method for producing the copolymerized polyethylene naphthalate in the present invention, a method in which an acid is directly esterified with glycol and then polycondensation reaction is carried out (D
E method) or a method (EI method) in which a dialkyl ester is used as an acid component, a transesterification reaction between the dialkyl ester and a glycol is performed, and then a polycondensation reaction is performed can be preferably used.

Examples of the dialkyl ester include dimethyl ester, diethyl ester, dipropyl ester and the like, and dimethyl ester is particularly preferable.

In the present invention, the haze of the copolymerized polyethylene naphthalate film is preferably 2.0% or less. It is more preferably 1.5% or less, and particularly preferably 1.0% or less. If the haze exceeds 2.0%, the transparency of the film is lowered, which is not preferable as a film for photographic light-sensitive materials.

In the present invention, the yellow index (Y _ID ) of the copolymerized polyethylene naphthalate film is 4.
The following is preferred. If the Y _ID exceeds 4, it is not preferable because the color tone becomes uneven when used as a color film.

The copolymerized polyethylene naphthalate film of the present invention is not particularly limited by its production method, and is preferably produced by the following method, for example.

The above copolymerized polyethylene naphthalate is
The film is extruded at a temperature of melting point (Tm) + 10 ° C. to Tm + 30 ° C. and rapidly cooled to obtain an unstretched film, and the unstretched film is then uniaxially (longitudinal or transverse) (Tg-10) to
Stretching at a temperature of (Tg + 50) ° C. (Tg: glass transition temperature of copolymerized polyethylene naphthalate) at a draw ratio of 2 to 5 times, and then in a direction perpendicular to the stretching direction (when the first stage stretching is in the longitudinal direction). Is the second direction stretching in the transverse direction)
Stretching is performed at a temperature of g (° C) to (Tg + 50) ° C at a draw ratio of 2 to 5 times. Then, heat setting treatment is further performed at a temperature higher than the Tg by 60 ° C. or more and 120 ° C. or less to obtain the target copolymerized polyethylene naphthalate film.

The thickness of the biaxially stretched film can be appropriately selected depending on the mode of use as a photographic light-sensitive material.
The thickness is preferably 0 μm, more preferably 40 to 150 μm.

The copolymerized polyethylene naphthalate film of the present invention may be provided with slipperiness depending on the application. The means for imparting slipperiness is not particularly limited, but inclusion of inert particles in the polymer, application of a slippery agent to the film, or the like is known as a general method, and it is possible to use these. it can.

As a method of incorporating the inert particles, for example, a method of adding SiO ₂ , BaSO ₄ , CaCO ₃ , aluminate myricate, crosslinked organic particles or the like to the polymer,
A method of precipitating a catalyst or the like during the production of copolymerized polyethylene naphthalate can be mentioned. From the viewpoint of ensuring the transparency of the film, the particles to be added from the outside preferably have a refractive index close to that of the copolymerized polyethylene naphthalate, such as BaSO ₄ , alumina silicate, crosslinked organic particles ( Crosslinked polystyrene etc.) are preferred.

Further, in the case of containing the inert particles, in order to obtain transparency of the film, a layer containing the inert particles is laminated thinly on at least one surface of the polyethylene naphthalate film which does not substantially contain the particles. The method of doing is also preferable. As this means, for example, a co-extrusion method using a plurality of extruders and feed blocks, or a multi-manifold die can be cited as an effective means.

The copolymerized polyethylene naphthalate film of the present invention has excellent transparency, hue, thermal stability and curl resistance against curling, and therefore, for example, film for photography, roll film for still photography, roll film for movies, X
It can be used as a base film for a wide range of photography such as a line roll film and a plate making film.

[0030]

The present invention will be described in more detail with reference to the following examples, but the present invention is not limited to the examples without departing from the scope of the invention. In addition, "part" in an Example means a weight part, and "mol" means the number of moles with respect to 10 < ⁶ > g of acid components. Further, the measurement of each characteristic value in the examples is performed by the following methods.

(1) Film haze (cloudiness) According to JIS-K6714, the haze of the film is determined by an integrating sphere type HTR meter manufactured by Nippon Seimitsu Optical Co., Ltd.

(2) Film yellow index (Y
_ID ) Using a color difference meter SZ-Σ90 manufactured by Nippon Denshoku Industries Co., Ltd., Y _ID of the film is calculated by the following formula.

[0033]

[Equation 1]

X, Y, Z = tristimulus values of light defined in the international CIE standard

(3) Delamination whitening rate of film (delamination resistance) A film sample was cut into a size of 80 mm × 80 mm, lightly folded in two by hand, sandwiched between a pair of flat metal plates, and then a pressing machine. Predetermined pressure P ₁ (kg /
cm ² G) for 20 seconds. After pressing, the folded film is returned to its original state by hand, sandwiched between the metal plates, and pressed at a pressure P ₁ (kg / cm ² G) for 20 seconds. Then, the sample film is taken out, and the length (mm) of the whitened portion appearing in the fold is measured and totaled.

Pressing pressures P ₁ = 1, 2, 3, 4, 5, 6 (kg /
The above measurement is repeated for cm ² G).

Length of the whitened portion at each press pressure (m
The average value of the sum of m) occupies the entire length (80 mm) of the fold, and is used as the fold delamination whitening rate, and this value is used as an index indicating the likelihood of delamination of the film.

[0038]

[Equation 2]

(4) Curl recovery rate The film sample was cut into 120 mm × 32 mm,
After winding it around the core of 10mm diameter in the longitudinal direction,
After the time treatment, release from the core. Then, after soaking in distilled water at 40 ° C. for 15 minutes, the sample is hung vertically in the longitudinal direction, and dried for 3 minutes in a constant temperature air bath at 55 ° C. under a load of 5 g. Next, the distance (A: mm) between the upper end and the lower end of the film is calculated excluding the load. The curl recovery rate is expressed by the following formula.

[0040]

(Equation 3)

Example 1 92 parts of 2,6-naphthalenedicarboxylic acid dimethyl ester and 8 parts of 2,6-tetralindicarboxylic acid dimethyl ester and 56 parts of ethylene glycol were used as transesterification catalysts of manganese acetate tetrahydrate. Using 025 parts (1.02 mol), a transesterification reaction was carried out according to a conventional method, and then 0.019 parts (1.35 mol) of trimethyl phosphate was added to substantially end the transesterification reaction.

Next, 0.017 parts (1.64 moles) of amorphous germanium oxide was added to the reaction product, followed by polycondensation reaction under high temperature and high vacuum to obtain an intrinsic viscosity (phenol /
Tetrachloroethane mixed solvent, 35 ° C) 0.62dl /
g of copolymerized polyethylene naphthalate was obtained.

The pellets of the copolymerized polyethylene naphthalate were dried at 180 ° C. for 5 hours, fed to an extruder hopper and melted at a melting temperature of 295 ° C. The molten polymer was passed through a 1.2 mm slit die and a surface temperature of 40. It was extruded on a rotary cooling drum at ℃ and rapidly cooled to obtain an unstretched film. The unstretched film thus obtained is heated to 120 ° C.
It is preheated to 1 mm, heated by a single IR heater having a surface temperature of 900 ° C. from above 15 mm between low-speed and high-speed rolls, and stretched to 3.0 times, and then fed to a stenter.
It was stretched 3.3 times in the transverse direction at 0 ° C. The obtained biaxially oriented film was heat set at a temperature of 220 ° C. for 10 seconds in a nitrogen stream to obtain a copolymerized polyethylene naphthalate film having a thickness of 95 μm. The intrinsic viscosity of this film is 0.60 dl
/ G.

The obtained film was heat-treated at 115 ° C. for 2 days and the film characteristics were measured. As shown in Table 1, it was good.

Example 2 The same procedure as in Example 1 was carried out except that the charged amounts of 2,6-naphthalenedicarboxylic acid dimethyl ester and 2,6-tetralindicarboxylic acid dimethyl ester were changed as shown in Table 1, and the film characteristics were obtained. Was measured.
Shows good properties as a photographic base material. However, further tetralindicarboxylic acid component copolymerization is not preferable because it causes deterioration in curl recovery rate.

[Comparative Example 1] 100 parts of 2,6-naphthalenedicarboxylic acid dimethyl ester and ethylene glycol 5
A film was obtained in the same manner as in Example 1 except that 6 parts were transesterified as in Example 1. This film had a Y _ID of more than 4, and could not satisfy the required characteristics as a base material for a photographic film.

[0047]

[Table 1]

[0048]

According to the present invention, excellent transparency, hue,
It is possible to provide a copolymerized polyethylene naphthalate film which has both delamination resistance and curling curl resistance and is particularly useful as a base material for a photographic photosensitive film.

Claims (3)

[Claims] 1. A copolymerized polyethylene naphthalate film comprising a copolymerized polyethylene naphthalate, wherein the main acid components of the copolymerized polyethylene naphthalate are naphthalenedicarboxylic acid and tetralindicarboxylic acid. 2. The acid component of the copolymerized polyethylene naphthalate is 80 to 99.5 mol% of naphthalenedicarboxylic acid and 0.5 to 20 mol% of tetralindicarboxylic acid, the haze of the film is 2.0% or less, and the yellow index. The copolymerized polyethylene naphthalate film according to claim 1, wherein (Y _ID ) is 4 or less. 3. The copolymerized polyethylene naphthalate film according to claim 1, wherein the film is a base film for a photographic light-sensitive material.