JPS62242515A - Manufacture of polyester film - Google Patents

Abstract

PURPOSE:To prepare a membrane with a uniform thickness at high speed by melting and extruding filmily a polyester composition containing a specified quantity of polyalkylene glycol and/or its derivative and a specified quantity of alkaline metal salt derivative of sulfonic acid as alkaline metal, adhering electrostatically to a rotating cooling roll, cooling and solidifying quickly. CONSTITUTION:Polyalkylene glycol and-or its derivative, 0.1-10wt% against polyester, is added. In case of forming alkaline metal salt of sulfonic acid, sulfonic acid and alkaline metal compound are added to polymerization process at an optional stage. Only when alkaline salt derivative of sulfonic acid is used, the effect of combination of polyalkylene glycol to enhance electrostatic tight layer properties is developed. The adding quantity of alkaline salt derivative of sulfonic acid against polyester is 0.0003-0.1wt% as alkaline metal. As the structure of electrostatic application device, structure of electrode, whether counter electrode is or not, relationship of position between electrode and counter electrode and current value as electrostatic application terms are to be set optionally.

Description

DETAILED DESCRIPTION OF THE INVENTION (Industrial Application Field) The present invention relates to a method for manufacturing a polyester film with a uniform thickness ratio with high efficiency. Saturated linear polyester has excellent mechanical curvature and heat resistance.

For developing weather resistance, [stun axial ratio, chemical resistance ratio, etc.] Packaging applications, photographic applications, [temperature applications,! It is widely used in a wide range of fields such as 11K tape. Usually, a polyester film is obtained by extruding polyester by /8 melt extrusion, followed by biaxial grinding. In this case, in order to improve the uniformity of the film thickness and the degree of casting, it is necessary to maintain a high density between the sheet material and the drum surface when the sheet material is melt-extruded from the extrusion die and rapidly cooled on the surface of the rotating cooling drum. 11 ratio must be increased.

As a method of increasing the density Va between the [F-)-like material and the drum surface, a wire-wrapped [&
A high voltage is applied to deposit static electricity on the top surface of the unsolidified sheet material, and I! N sheet as cooling body # [ll! f
It is known that a method of rapidly cooling the material while it is attached (hereinafter referred to as "contact casting method") is still in use (for example, Japanese Patent Publication No. 37-6142).

Uniformity of film thickness is an extremely important characteristic of film quality, and film productivity is determined by casting! Since it is extremely important to increase the casting speed in order to improve the casting quality because it is directly dependent on the ff, great efforts are being made to improve the static [density].

It is known that increasing the amount of electric charge on the surface of the y-)-shaped object is an effective means for suppressing static shielding.

In addition, #p) The sheet surface (
7)? [...It is known that modifying the polyester raw material used in the production of polyester film is an effective means for increasing 1k in i'.

Conventionally, as the modification method, a method is known in which an alkali metal compound or an alkaline earth metal compound is added in one run of polyester production. However, in order to impart a high level of static density with this method, it is necessary to add a large amount of metal compound. There is a problem that the addition of these metal compounds lowers the stability ratio of polyester. One method has been proposed to improve stability by using a phosphorus compound in combination, but it cannot be said to have reached a satisfactory level.

(Disadvantages to be Solved by the Invention) In view of the above-mentioned circumstances, the present inventors have diligently studied a method of imparting a high level of static and transparent properties using as little metal compound as possible, and have completed the present invention. . In other words, the present invention is a method that is completely unknown in the past, in which the structure of the base material itself of polyester is modified to enhance the effect of imparting the softness and dense layer properties of the metal compound, and to reduce the need for metal compound additives. The purpose of the present invention is to provide a method for forming a polyester film of excellent thickness uniformity and high quality at high 4 degrees using a polyester composition modified by (Means for solving the problem) ) The present invention uses polyalkylene glycol and H/M or its i conductor as an alkali metal of 0.1 to 10% and an alkali terminal salt derivative of sulfonic acid as an alkali metal.
．． This is a method for producing a polyester film, in which a polyester composition containing 1% by weight is melt-extruded into a film, and then the melt-extruded film is electrostatically densely layered on a rotating cooling roll and rapidly solidified.

A preferred embodiment of the present invention is a polyester film manufacturing method in which the polyester film is further abraded in at least one direction by 1.1 times or more.

The polyester of the present invention may be any polyester or a copolymer thereof that can be obtained from a di-salt, 1-acid and a dihydric alcohol and has a film-forming ability. Typical such polyesters include polyethylene terephthalate and copolymers thereof, but are not limited thereto.

Examples of the polyalkylene glycol used in the present invention include polyethylene glycol, polypropylene glycol, polytetramethylene glycol, and copolymers thereof, and polyethylene glycol and copolymers thereof are particularly preferred.

The molecular weight of the polyalkylene glycol used in the present invention is not particularly limited, but is preferably 200 to 200,000°, preferably 300 to 20,000°. More preferable ti400
~6,000 is preferred. If the molecular acid is less than 200, the effect of improving the electrostatic density layer property will be small, and if the molecular weight is more than 200,000, the graining ratio to polyester will be lowered and coarse protrusions will be formed when formed into a film, which is not preferred. There are no limitations on the terminal groups, and either one having a hydroxyl group at both ends, one having a hydroxyl group only at one end, or one having both ends blocked with other bonds can be used.

In addition, polyalkylene glycol is one of the glycol components.
Even if you add 7J in the form of thick polyester, it will not accumulate.

The amount of the polyalkylene glycol and/or its derivative is 0.1 to 10 weights + 1 weight, preferably 0.2 to 5 weights, relative to the polyester.

A 0.1 overlapped edge chip is not preferable because the effect of improving #iI electrical shielding properties is reduced. On the other hand, if you increase 10m1t%tm, y
# It is not preferable because the effect of improving mWMtt is reduced by 15% and the heat resistance of polyester is lowered.

Examples of the alkali metal salt of sulfonic acid conductor used in the present invention include a compound v/J having the structure shown below.

SO3Me Here, R is an alkyl crystal having 1 to 20 carbon atoms.

hie is an alkali metal such as L I b N as Km C8.

For the alkali metal salt ws of nuclear sulfonic acid, an alkali metal salt derivative of sulfonic acid may be added directly to the polyester manufacturing process, or a sulfonic acid compound and an alkali metal salt compound may be added to the polyester manufacturing process, Polyester I
The alkali metal salt derivative of the sulfonic acid may be produced during the vlli production process.

Specific examples of alkali metal salt derivatives of sulfonic acid include sodium methanesulfonate, potassium methanesulfonate, and sodium ethanesulfonate.

Lithium benzenesulfonate, sodium benzenesulfonate, potassium benzenesulfonate, lithium p-toluenesulfonate, sodium p-)toluenesulfonate,
Sodium m-toluenesulfonate, 0-)A/Sodium toluenesulfonate.

Sodium p-ethyl benzenesulfonate, sodium dodecyl benzenesulfonate, potassium dodecylbenzenesulfone, sodium oftagylbenzenesulfonate, potassium octadecylbenzenesulfonate, sodium benaphthalenesulfonate % frozen-naphthalene sulfonate Examples include potassium. Among these compounds, the sodium salt or potassium salt of sulfonic acid is particularly preferred.

When producing an alkali metal salt derivative of sulfonic acid in the polyester manufacturing process, the sulfonic acid and alkali metal compound forming the alkali metal salt derivative of sulfonic acid should be added to the 1 km process. The sulfonic acid may be added in the form of an acid or in the form of an ester. Examples of alkali metal compounds include alkali metal fatty acid salts and aromatic carboxylate alkoxides.

Examples include glycoxide, oxide, hydroxide, and the like. The sulfonic acid compound is preferably used in the form of an acid, and the alkali metal compound is preferably used as a lower fatty acid salt.

W? only when the alkali salt derivative of the sulfonic acid is used.
[Dense J# The effect of combined use of polyalkylene glycol on improving properties is revealed. Even with metal salts of sulfonic acid, metal salts other than alkali metals do not produce combined young fruits. In addition, even if an alkali metal salt is used, the combined effect will not be exhibited in the presence of acids other than sulfone-stiff conductors. For example, even with sulfuric acid or salts of alkyl sulfates, the combined effect will not be exhibited. In the case of conventional additives for improving electrostatic adhesion, such as alkali metal compounds and alkaline earth metal compounds, no effect is obtained when used in combination. In systems other than the method of the present invention, the concomitant use of polyalkylene glycol actually acts in the direction of lowering the static WL tightness.

The amount of addition of the alkali metal salt derivative of sulfonic acid to the polyester is 0.0003 to 0.0003 as the alkali metal.
1 weight iit*, preferably 0.001 to 0.05 weight %
, more preferably 0.002 to 0.02 heavy wrinkles. At 0.0003 mm%, the effect of improving static 1C tightness ratio becomes small, and when it exceeds 0 or 1 [IM, the effect of improving electrostatic adhesion becomes saturated and the heat resistance ratio of polyester decreases. This is not preferable because it causes a gap between the two.

The alkali metal salt derivative of the polyalkylene glycol or sulfonic acid 114j
! ! The addition of a component that forms a derivative can be selected as appropriate at any stage in the process, but the addition of a component that forms an alkali metal salt M@ form of sulfonic acid or an alkali metal salt derivative of sulfonic acid is performed during an esterification reaction or It is preferable to add the polyester before the start of the transesterification reaction and before the solid 4f melon of the polyester reaches 0.2.

The polyester composition used in the method of the present invention is not particularly limited as long as it satisfies the above conditions, and for example, polyester produced by a transesterification method may be used.* +1
! Polyester produced by a grafting method may also be used.

As the transesterification catalyst and the t1j Tokai catalyst for polyester production, any conventionally known catalysts can be selected and used as appropriate. In addition, M during polyester production
Addition of 6-millimeter Ii to suppress IJ reaction or improve stability of polyester! There is no restriction on adding i11 either. It was a cabinet. [[11 Polynisdel produced by an 11-minute process may be used, or polyester 1 produced by a continuous process may be used. Furthermore, it may be impregnated with an m-agent consisting of inorganic or organic particles, or particles precipitated in the polyester manufacturing process, so-called internal particles, may be incorporated as long as one or more requirements are met.

In the method of the present invention, # the structure of the voltage applying device and static 1t+:
l] There are no limitations on the additional conditions, and they may be set arbitrarily. For example, in the ffl structure of an electrostatic application device, the electrode structure,
The counter electrode should be set to nothing, the positional relationship between the electrode and the counter electrode, the extrusion port, the cooling roll, etc., and the electric current application conditions may be set as desired.

The film used in the method of the present invention is an unpolished stretched film.

- Either an axially abrasive film or a biaxially stretched film may be used, but the ratio is 1.1 times or more in at least one direction.

Preferably 2. Cattle that are ground more than S@ are preferable because they improve mechanical properties and other physical properties, and are used for various purposes.

(Example) Next, Examples and Comparative Examples of the present invention will be shown. All parts in the examples refer to direct parts unless otherwise specified. The measurement method used is shown below.

(1) Dissolve the existing Vit polymer in a mixed solvent of phenol (6 parts) and tetrachloroethane (4 parts, 1 part).

Measure at 30°C.

(2) A tungsten wire pole was provided between the extrusion die and the cooling drum, and casting was performed by applying a voltage of 10 to 15 KV between the VT pole and the casting drum. The surface of the casting FiL fabric is observed with the naked eye and evaluated at the casting speed at which pinner purpling begins to occur. The higher the casting speed of the polymer, the better the molding properties.

(3) Vertical Iv uneven contact type i! The film thickness was measured for a film length of 10 Fff using a 14-thickness needle, and the thickness unevenness was calculated using the following formula.

Example 1 519 parts of terephthalic acid, 4 parts of ethylene glycol (EG)
31 g, ) lJzf-ruamino 0.16 part in a stirred pot, a
Reduction column and pressure IIl! The autoclave was placed in a stainless steel autoclave with a 1wi element exchanged, and the gauge pressure was maintained at 2.5 kt/d. A chemical reaction was carried out. After 120 minutes had passed from the start of the reaction, the pressure was released to obtain a product with an esterification rate of 98%. This esterification product contains polyethylene glycol 31 with a molecular weight of 2000.
．． Add 5 parts and bring to normal pressure.

Stir at 240°C for 10 minutes, add p-toluene, 0.25 parts of sodium phosphate (based on the produced polyester)
50 ppm (in terms of atoms) was dissolved in 10 Toshibe Tani's EGK, and 1.2 parts of Kaolinai with an average particle size of 0.7μ was divided into 8 parts of EG. Added and stirred for an additional 10 minutes at normal pressure and 240°C, 240
℃ was transferred to a Wt recombination reactor, the temperature was raised to 275℃ over 45 minutes, and the pressure of the reaction system was gradually lowered to 0.05 al.
Polymerization and reaction were further carried out at the same temperature and pressure for about 85 minutes to obtain a solid polymer f with a viscosity of 0.630.

The resulting polymer gauze! The fI note was 65 m/min, which was extremely good.

In addition, 52 cases where film formation was carried out using the above raw materials and under conditions of manure.
Even when the film was formed at a take-up speed of 20 m7, a high-quality film with no defects on the film surface and with thickness unevenness in the longitudinal direction of 6.5 factors or less was obtained.

Film forming conditions Film thickness = 12μ (after 2-screw grinding) Extrusion temperature: 2
90°C f # electric tight condition? 0.25mm φSO5 electrode, applied voltage 1
0 to 15KV Vertical force ratio = 3.5 times Grinding temperature: 90℃ IfJ1 grinding ratio: 3.5 times V1#, Temperature: 130℃ Heat set degree M = 220℃ Comparative example 1 Example 1 A polyester was obtained in the same manner as in Example 1 except that the addition of polyethylene glycol was stopped. The static e of the obtained polyester [adhesion is 15 m/
It was a minute. Further, a film was formed using the polyester under the same conditions as in Example 1.

To obtain a crystalline film like that obtained in Example 1, 5
Q tpt III film could only be formed at a take-up speed of 7 minutes or less.

Comparative Example 2 A polyester was obtained in the same manner as in Example 1, except that the addition of p-toluenesulfone sodium chloride was omitted. Tokuuretaholyester no Shizuka￥S: W
The normal punch was 15 m/min. 9) The polyester was used to form an @lI film under the same conditions as in Example 1, but in order to obtain a high quality film like that obtained in Example 1, it was necessary to form the film only at a drawing speed of 50 m/min or less. I couldn't do it.

Comparative Examples 3 to 6 In the method of Example 1, sodium furyl, sodium sulfate, sodium acetate, and sodium bromide were used in place of sodium p-toluenesulfonate, respectively. Polyester was obtained by the same method as in Example 1 except that the concentration was 50 ppm in terms of Na atom.The electrostatic adhesion of the obtained polyester was 10 to 15 m/min. The polyester was melted to form a film under the same conditions as in Example fA1, but in Example 1? 5 Q. How to get a high-quality film that looks good
yn Only with a pick-up speed of 7 minutes or less! Could not pus.

Examples 2 to 8 Using the method of Example 1 to prepare polyalkylene glycol and/or sulfonic acid alkali gold conductor IJ
Polyester df) lp manufactured by modifying aim
% adventure R1! ! : and Example 1 using the polyester
Table 1 shows the maximum aIPIII speed when using 11411# under the same conditions. It can be seen that high-quality films were formed at high take-up speeds in all Examples.Example 9 The esterified product esterified by the method of Example 1 was added to the polyethylene glycol 31.5 parts of molecule [1000]. was added and stirred at normal pressure and 240°C for 5 minutes.

0.107 parts of sodium acetate (50 ppm in terms of Na atoms based on the produced polyester) was added as a solution dissolved in EG, and stirred for an additional 5 minutes at normal pressure and 240°C. 0.248 part of 11111 hydrate was added as f8 liquid in which EG4C was dissolved,
After further stirring for 5 minutes at normal pressure and 240°C, the average particle size became 0.
1.2 parts of 7μ kaolinite was added to EG as a separated solution, and the mixture was heated at normal pressure and 240°C for another 10 minutes to obtain a 0.632 polyester. The electrostatic adhesion of the obtained polyester was 67 m/min, which was 9. In addition, when a film was formed using the polyester as a raw material under the same conditions as in Example 1, 230 m
Even when the film was formed at a take-up speed of 7 minutes, a high-quality film with no defects on the film surface and with thickness unevenness in the longitudinal direction of 6.5% or less was obtained.

Comparative Example 7 Polyethylene glycol was prepared by the method of Acti & AJ 9.
Polyester 1 was prepared in the same manner as in Example 9 except that
The static VL electric W ratio of the nine polyesters obtained is 15m.
/minute. Also, using the polyester, 1lII! However, in order to obtain a high quality film like that obtained in Example 9, it was possible to form the film only at a take-up speed of 50 m/min or less.

Comparative Example 8 A polyester was obtained in the same manner as in Example 9 except that sulfur-IJium acetate was not added. , 74
The velocity of the polyester obtained was 15,771/min. In addition, the polyester was used as a sea bream in the same manner as in Example 9, but in order to obtain a high-quality cage film like that obtained in Actual Example 9, it was necessary to use a take-up speed of 5 Qnt 1 minute or less.
I couldn't ll'jl.

(Effect of the invention) When a polyester film is produced by the method of the invention, 11
Finished with uniformity! It has the effect of being able to produce an excellent polyester film at high speed.

Claims (2)

[Claims] (1) 0.1 to 10% by weight of polyalkylene glycol and/or its derivative and 0.0003 to 0.0% by weight of an alkali metal salt derivative of sulfonic acid.
A method for producing a polyester film, which comprises melt-extruding a polyester composition containing 1% by weight into a film, and then electrostatically adhering the melt-extruded film to a rotating cooling roll to rapidly solidify it. (2) A method for producing a polyester film, which further stretches the polyester film according to claim 1 by 1.1 times or more in at least one direction.