KR19990071216A - Manufacturing method of biaxially oriented polyester film - Google Patents

Abstract

The present invention relates to a biaxially oriented polyester film, wherein a film made from conventional polyester has a processing speed, for example, a printing process for packaging, or a magnetic coating for magnetic recording media, calendaring, and slitting. As the surface of the film is worn out due to the increase in contact with the roll, problems such as post-processing process or product characteristics (quality) occur.

Accordingly, in the present invention, in order to improve the hardness of the film in polyester, 0.03 to 0.21% by weight of aerosol-based fine silica particles having an average particle diameter of 0.02 to 0.1 µm having a hardness of 6 or more, and inert particles B having different particle diameters, The polyester is prepared by using a biaxially oriented polyester film in a range in which the inert particles C satisfy a specific dosage ratio, and the prepared polyester can be applied to both a transesterification method and a direct exchange reaction method, and a reactor Using either batch or continuous type, it is possible to produce a film that can satisfy both winding properties, running properties and electronic properties simultaneously. The production method of such biaxially oriented polyester film provides excellent electronic properties, running properties, abrasion resistance and repeated durability. It is to be able to obtain a good film.

Description

Manufacturing method of biaxially oriented polyester film

The present invention relates to a biaxially oriented polyester film, and more particularly, by adding two or more kinds of inert particles having a high hardness lubricant and particle diameter to a specific particle size and a specific input ratio, so that the electronic properties, runability, wear resistance, and durability And to the production of biaxially oriented polyester films with improved scratch resistance.

Polyester, represented by polyethylene terephthalate, has a stable chemical structure, high mechanical properties, and is excellent in heat resistance, chemical resistance, and durability, and is used not only for capacitors, medical devices, packaging materials, photographic films, and labels, but also for magnetic recording. It is widely used for many purposes such as description of a medium.

Films made from these polyesters are processed after the surface of the film is worn on the rolls that come into contact with processing speeds, for example, printing processes for packaging purposes, or process speeds such as magnetic material application, calendaring, and slitting for magnetic recording media. Process or product characteristics (quality) problems arise.

Particularly, in the case of magnetic use, in order to improve the running and processability of the film, inorganic materials such as calcium carbonate, silica, kaolin, and alumina are added as lubricants to form irregularities on the surface of the polyester film. There is a problem of deterioration of characteristics.

Recently, the improvement of the electron conversion characteristics according to the trend of high performance of the magnetic recording medium requires a film having a flatter surface.

Flattening the film surface to improve the electronic properties, which is one of the important requirements of customers, leads to poor running performance due to the increase of the coefficient of friction. The opposite results are shown.

Therefore, it is required to develop a film having excellent running characteristics, electronic characteristics, and wear resistance at the same time. Moreover, as the production speed of the tape is increased, the demands for driving characteristics, winding characteristics, scratch resistance, etc. at high speeds are also increasing. As the quality of the tape decreases due to the use of low-cost materials, the demand for durable films to prevent them is also increasing.

Many patents have been known to improve the scratch resistance and abrasion resistance of films by adding a high hardness lubricant, but are required for durability due to the increase in coarse particles due to a decrease in the dispersibility of the high hardness lubricant of fine particles or repeated use. In that the effect of improvement was somewhat lacking.

Accordingly, in the present invention, in order to solve the above problems, the high hardness lubricant is added to the polyester to improve the hardness of the film and at the same time add two or more kinds of inert particles of a specific particle size to the biaxially oriented polyester film. It is an object of the present invention to provide a method for producing a biaxially oriented polyester film having excellent abrasion resistance and good scratch resistance and repeated durability.

In order to achieve the above object, in the present invention, in order to improve the hardness of the film in the polyester, it contains 0.05 to 1% by weight of aerosol-based fine silica particles having an average particle diameter of 0.03 to 0.1 µm with a hardness of 6 or more. The inert particles B and the inert particles C, which differ from each other, are produced in a range satisfying a specific dosage ratio.

The polyester produced using the biaxially oriented polyester film production method of the present invention can be applied to either a transesterification method or a direct exchange reaction method, and the reactor is wound or runnable and electrons using either a batch or a continuous type. The film which can satisfy | fill the characteristic simultaneously can be manufactured, and the film excellent in electronic property, running property, abrasion resistance, and repeat durability can be obtained by the manufacturing method of such a biaxially-oriented polyester film.

Hereinafter, the present invention will be described in more detail.

In order to improve the hardness of a film in polyester, this invention contains the aerosol type fine silica particle of 0.03-0.21 micrometer of average particle diameter of 6 or more, and inert particle (B) which differs in particle size other than that 2 or more kinds of (C), wherein the inert particles (B) and (C) satisfy a relational expression of 2 <inert particle B input amount (WB) / inert particle C input amount (WC) <20 It is a manufacturing method of the biaxially-oriented polyester film.

In particular, the polyesters of the present invention comprise at least 80 mole% of ethylene terephthalate repeating units and the remaining amount of dicarboxylic acid components or oxycarboxylic acid components as other copolymerization components.

In addition, as the dicarboxylic acid of the present invention, isophthalic acid, para-methoxyoxyethoxybenzoic acid, 2,6-naphthalene dicarboxylic acid, 4,4'-dicarboxyl diphenyl, 4,4 'dicarboxyl benzo Phenone, bis (4-carboxydiphenyl) ethane, adipic acid, sefacinic acid, 5-sodium sulfoisophthalic acid, and the like. Examples of oxycarboxylic acids include propylene glycol, butanediol, neopentyl glycol, and diethylene glycol. , Cyclohexane dimethanol, paraoxy benzoic acid, etc. are mentioned.

The polyester is typically a PET obtained by polycondensation of dimethyl terephthalate and ethylene glycol, and in the preparation of such polyester, either a transesterification method or a direct exchange reaction method may be applied, and the reactor may be either batch or continuous. Can be used.

When carried out by the transesterification reaction, there is no particular limitation on the transesterification catalyst, and any conventionally known one can be used. For example, as the transesterification catalyst, any of alkaline earth metal compounds, such as magnesium compounds, zirconium compounds, sodium compounds, potassium compounds, gallium compounds, barium compounds, cobalt compounds, zinc compounds, and manganese compounds, is soluble in the reaction system. It's okay.

In addition, the polymerization catalyst is not limited, but may be suitably selected from antimony compounds, germanium compounds, and titanium compounds.

The fine silica particles or inert particles used in the present invention are inert particles with respect to polyester, and in the case of fine silica particles, the hardness is 6 or more in the aerosol type, and the average particle diameter is 0.03 to 0.1 μm, preferably 0.04 to 0.1 μm, and the dosage is When it contains 0.03-0.5 weight%, preferably 0.05-0.5 weight%, the effect of this invention can be exhibited.

In the case of two or more kinds of inert particles, the average particle diameter and content are not particularly limited, but in order to satisfy electronic characteristics, wear resistance, scratch resistance, running resistance and repeated durability, the particle diameter of the inert particles (B) <inert particles (C ) The effect of the invention can be increased when the ratio of the input amount of the inert particles having a difference in the average particle diameter, which is the particle size, satisfies the relation of 2 <input amount of inert particle B (WB) / input amount of inert particle C (WC) <20

The average particle diameter of the inert particles (B) is generally in the range of 0.1 to 0.8 mu m, preferably in the range of 0.2 to 0.8 mu m, and the addition amount thereof is generally in the range of 0.1 to 0.6 wt%, preferably in the range of 0.1 to 0.5 wt%.

In addition, the particle diameter of the inert particles (C) is generally in the range of 0.3 to 1.2 µm, preferably 0.3 to 1.0 µm, and the amount thereof is generally in the range of 0.01 to 0.3% by weight, preferably 0.01 to 0.2% by weight.

As described above, the inert particles used in the present invention are not particularly limited, but the inert particles (B) are preferably inert particles such as synthetic calcium carbonate and spherical colloidal silica, and in the case of the inert particles ((C)) A composition of calcium carbonate or the like and organic polymer particles is preferable, and each of the inert particles may be surface treated.

In the case of the fine silica particles of the inert particles used in the present invention, when the hardness is less than 6, it is insufficient to improve the hardness of the film surface, and when the average particle size is 0.03 μm or less or the input amount is 0.5% by weight or more, agglomeration between the fine silica particles This is not preferable because of the worsening of the magnetic tape dropout due to the formation of coarse particles.

On the other hand, when the particle size of the fine silica particles is 0.1㎛ or more, dropping is easy due to the lack of affinity according to the hardness difference with the polymer, which may cause scratches during post-processing or tape use, and when the input amount is 0.03% by weight or less, the present invention It is insufficient to improve scratch resistance and durability.

In addition, if the average particle diameter of the two or more inert particles added is less than the claims, the surface roughness of the film is lowered, so that the friction coefficient is increased, so that the runability is lowered. If it is added below the claims, roughening of the film is insufficient, and if it is added above the claims, it is not preferable because the dropout phenomenon of the magnetic tape appears due to the generation of coarse particles due to the flocculation of the lubricants.

Therefore, when the input ratio of the inert particles satisfies the relation of 2 <inert particle B input amount (WB) / inert particle C input amount (WC) <20, as shown in Table 1, the effect of improving runability, wear resistance, and repeat durability is effective. have.

If the input ratio (WB / WC) is greater than 20, the number of surface protrusions generated by inert particles of large particle size is relatively small, which is insufficient to improve the driving performance. When the input ratio is smaller than 2, the number of large protrusions is relatively large. Resulting in poor electronic properties.

When the relational expression of 2 <injection amount of inert particle B (WB) / inert particle C amount (WC) <20) is satisfied. Inert Particles (A) Inert Particles (B) Inert Particles (C) WA / WB Driving friction coefficient Wear Resistance (Grade) Scratch Resistance (Rating) Repeated durability (grade) Kinds Particle size (㎛) input(%) Kinds Particle size (㎛) input(%) Kinds Particle size (㎛) input(%) sleaze high speed Example 1 Aerosil 0.06 0.2 Calcium carbonate 0.4 0.4 Calcium carbonate 0.9 0.1 4 0.30 0.07 A A A Example 2 Aerosil 0.06 0.1 Calcium carbonate 0.4 0.4 Calcium carbonate 0.9 0.1 4 0.31 0.07 A B B Example 3 Aerosil 0.06 0.05 Calcium carbonate 0.4 0.4 Calcium carbonate 0.9 0.1 4 0.31 0.07 A B B Example 4 Aerosil 0.03 0.2 Calcium carbonate 0.4 0.4 Calcium carbonate 0.8 0.05 8 0.33 0.09 A A A Example 5 Aerosil 0.05 0.2 Calcium carbonate 0.5 0.4 Calcium carbonate 0.8 0.05 8 0.32 0.08 A A B Example 6 Aerosil 0.08 0.2 Calcium carbonate 0.5 0.4 Calcium carbonate 0.8 0.05 8 0.32 0.08 A A B Comparative Example 1 Calcium carbonate 0.5 0.4 Calcium carbonate 0.8 0.05 1.6 0.32 0.08 A C B Comparative Example 2 Silica 0.3 0.2 Calcium carbonate 0.8 0.1 2.7 0.33 0.08 B C B Comparative Example 3 Aerosil 0.01 0.1 Calcium carbonate 0.4 0.4 Calcium carbonate 0.9 0.1 2.25 0.31 0.07 A C C Comparative Example 4 Aerosil 0.06 0.02 Calcium carbonate 0.4 0.2 Calcium carbonate 1.0 0.1 2.5 0.30 0.06 B C C Comparative Example 5 Aerosil 0.05 0.2 Calcium carbonate 0.5 0.4 Calcium carbonate 0.6 0.05 1.2 0.35 0.11 C B B

Therefore, inert particles B having 0.05 to 1% by weight of aerosol-based fine silica particles having an average particle diameter of 0.03 to 0.1 µm having a hardness of 6 or more according to the claims of the present invention. It has a particle size relationship, and when the ratio of the dose of the inert particles is 2 <the dose of the inert particles B (WB) / the dose of the inert particles C (WC) <20, it is possible to obtain a film having excellent electronic properties, running properties, wear resistance and repeated durability. have.

Such polyester of the present invention is PET obtained by polycondensation of dimethyl terephthalate and ethylene glycol, and in the preparation of such polyester, any of a transesterification method and a direct exchange reaction method may be applied, and the reactor may be batch or continuous. You can use either.

When carried out by the transesterification reaction, there is no restriction on the transesterification catalyst, and any conventionally known one can be used.

For example, as the transesterification catalyst, half of alkali earth metal compounds such as magnesium compounds, zirconium compounds, sodium compounds, potassium compounds, gallium compounds, barium compounds, cobalt compounds, zinc compounds, and manganese compounds are soluble in the system. If you do.

The polymerization catalyst is also not limited but may be suitably selected from antimony compounds, germanium compounds and titanium compounds.

The polyester containing the inert particles prepared by the above method is sufficiently dried, melt-extruded and cooled by a Tie-die method or the like to form a non-stretched sheet, followed by biaxial stretching.

Although the manufacturing method of a film is not specifically limited, After extending | stretching 2.5-5.0 times in a longitudinal direction using the sequential biaxial stretching method, 3.0-5.0 times in a lateral direction and extending | stretching temperature are more than Tg point and below cold crystallization temperature, heat processing is common To produce a biaxially oriented polyester film of the present invention in the range of 180 to 230 ° C, preferably 190 to 220 ° C.

Hereinafter, although this invention is demonstrated in detail based on an Example, this invention is not limited to these Examples. In Examples and Comparative Examples of the present invention, various performance evaluation of the produced polyester film was performed by the following method.

1) Average particle diameter

After dispersing the inert particles in ethylene glycol, the volume average particle diameter (mu m) was measured using a centrifugal sedimentation particle size analyzer (SA-CPII) manufactured by Shimadzu Corporation.

2) Surface roughness

Surface roughness was measured using a contact surface roughness meter (SURFCORDER SE-30D) of Kosaka Research Institute (Japan). Measurement conditions The needle diameter = 2 占 퐉, cut-off = 0.08 mm, measurement length = 5 mm, and 7 points after the measurement of 5 points except the maximum and minimum values were averaged.

3) wear resistance

Using the tape runability tester (TBT-300H) of the Yokohama Systems Research Institute (Japan), the film was slit to a width of 1/2 inch, and then the tape guide pin was subjected to frictional running on the tape guide pin at a running speed of 3.3 cm / sec. Abrasion resistance is evaluated by visual or photographic observation of the powder on the surface of the powder.

Class A: If there is no powder at all on the guide pin,

Class B: If the guide pin has a percentage of 1/5 of the side pin area,

C class: If the guide pin has about 1/2 of the side pin area,

Class D: If hundredths occur on the entire guide pin,

4) traveling

Using a tape runability tester (TBT-300H) from Yokohama Systems Research Institute (Japan), run a slitting film with a width of 1/2 "in a 20 ° C / 60RH% atmosphere and calculate the running friction coefficient k as follows. .

k = 1n (Tout / Tin)

Where Tin is the inlet tension and Tout is the outlet tension.

Low speed running

After fixing the guide pin, the contact angle of the film was measured at 180 degrees, the running speed was 3.3 cm / sec, and the inlet tension was 30 g. The running friction coefficient µk at low speed travel is determined to be less than or equal to 0.35, based on 0.35 as a defect.

B) High speed running

After fixing the guide pin, the contact angle of the film was 180 degrees, the running speed was 50 cm / sec, and the inlet tension was set to 300 g to measure the runability. The running friction coefficient μk in the high speed travel is determined to be less than or equal to 0.10, based on 0.10 as a defect.

5) Scratch resistance

Using the tape runability tester (TBT-300H) of Yokohama Systems Research Institute (Japan), the film was slit to a width of 1/2 inch and then frictionally run on the tape guide pin at a travel speed of 2,300 m / min, and then the film surface. The degree of scratches is assessed by visual or photographic observation.

Grade A: if there is no scratch on the film,

Class B: If the film has about 1/5 of scratches,

Grade C: If the film has scratched about 1/2,

Class D: If scratches occur on the entire film,

6) Repeat durability

Using the tape runability tester (TBT-300H) of the Yokohama System Research Institute (Japan), the film was slit to a width of 1/2 inch, and the tape guide pin was repeatedly run on the tape guide pin at a traveling speed of 50 m / min. Visually or photograph the white powder on the surface of the tin and evaluate the change in exit tension with repeated driving.

Class A: If there is no powder at all on the guide pin,

Class B: If the guide pin has about 1/5 of the side pin area,

C class: If the guide pin has about 1/2 of the side pin area,

Class D: If hundredths occur on the entire guide pin,

Example 1

Ethylene glycol slurry (inert particles A) containing 0.2% by weight of aerosol fine silica particles having an average particle diameter of 0.06 µm, and ethylene glycol slurry (inert particles B) containing 0.4% by weight of 0.4 µm of synthetic calcium carbonate having an average particle diameter of Ethylene glycol slurry (inert particles C) containing 0.1% by weight of 0.9 μm of synthetic calcium carbonate was prepared, respectively. In the presence of the above ethylene glycol slurry in a batch reactor was subjected to transesterification.

The above-mentioned transesterification material was subjected to polycondensation reaction with 0.0444% by weight of antimony trioxide as a polymerization catalyst to prepare a polyester polymer having a molecular weight of 20,000 and then dried at 180 ° C. for 8 hours, followed by melt extrusion by a tee-die method or the like. A non-oriented sheet was made by the method, stretched 3.1 times in the longitudinal direction and 3.7 times in the transverse direction at 90 ° C., followed by heat treatment at 210 ° C. to prepare a biaxially oriented polyester film having a thickness of 14 μm.

Examples 2-6 and Comparative Examples 1-5

Among the conditions of Example 1, the average particle diameter, the addition amount, and the addition amount ratio of the inorganic particles added during the polymerization were changed to prepare films having characteristic differences, respectively.

The evaluation results of the properties of the films are shown in Table 1, respectively. When the particle diameters and protrusion heights of the inert particles specified in Table 1 fall within the claims of the present invention, it is possible to produce a film that can simultaneously satisfy the winding property, the running property, and the electronic properties.

As described above, the fine silica particles or the inert particles used in the present invention are inert particles for polyester, and in the case of the fine silipa particles, the hardness is 6 or more in the aerosol type, and the average particle diameter is 0.03 to 0.1 탆, preferably 0.04 to 0.1. In the case of 占 퐉 and the added amount of 0.03 to 0.5% by weight, preferably 0.05 to 0.5% by weight, the effect of the present invention can be exhibited.

In the case of two or more kinds of inert particles, the average particle diameter and content are not particularly limited. ) The effect of the present invention can be increased even when the ratio of the input amount of the inert particles having a difference in the particle size, which is the particle size, satisfies the relation of 2 <input amount of inert particle B (WB) / input amount of inert particle C (WC) <20 have.

The polyester produced using the biaxially oriented polyester film of the present invention as described above can be applied to any of the transesterification method and the direct exchange reaction method, and the reactor is wound by using either batch or continuous type. A film capable of satisfying both running characteristics and electronic characteristics can be produced, and a film having excellent electronic characteristics, runability, abrasion resistance, and repeat durability can be obtained by the method for producing a biaxially oriented polyester film.

Claims (5)

2 or more types of inert particle (B) which contain 0.03-0.21 weight% of aerosol type fine silica particles of average particle diameter 0.02-0.1 micrometer whose hardness is 6 or more, in order to improve the hardness of a film in polyester. (C) The manufacturing method of the biaxially-oriented polyester film characterized by the above-mentioned. The method for producing a biaxially oriented polyester film according to claim 1, wherein the average particle diameter of the inert particles (B) is smaller than the average particle diameter of the inert particles (C). The method according to claim 1 or 2. Method for producing a biaxially oriented polyester film, characterized in that the ratio of the input amount of the inert particles (B) and (C) satisfies the relationship of 2 <the input amount of the inert particle B (WB) / the input amount of the inert particle C (WC) <20 . The synthetic inert particles according to claim 1, wherein the inert particles (B) have spherical colloidal silica, synthetic calcium carbonate, and inert particles (C) having an average particle diameter of 0.1 to 0.8 µm. It is a composition, such as calcium, and an organic polymer particle, The manufacturing method of the biaxially-oriented polyester film characterized by the above-mentioned. The biaxially oriented poly-polyester according to claim 1, wherein 0.01 to 0.6% by weight of inert particles (B) are added based on polyester, and 0.01 to 0.3% by weight of inert particles (C). Method for producing an ester film.