KR100229941B1 - Multi-layered polyester film having an improved slipperiness and abrasion resistance - Google Patents

Abstract

In the polyester film having a main repeating unit of ethylene terephthalate or ethylene naphthalate, the present invention comprises 0.01 to 3 parts by weight of particles insoluble in polyester having an average particle size of 0.5 to 3 µm with respect to 100 parts by weight of polyester. A layer (B) and 0.01 to 3 parts by weight of aluminum hydroxide particles having an average particle diameter of less than 0.001 to 0.5 µm with respect to 100 parts by weight of polyester, each consisting of both outer layers (A) and (C) having a thickness of 0.5 to 2 µm. By providing a three-layer or more multilayer polyester film, the multilayer polyester film of this invention is excellent in an activity and abrasion resistance.

Description

Multilayer Polyester Film with Improved Mobility and Wear Resistance

The present invention relates to a multi-layered polyester film, and more particularly, it is excellent in the activity produced by co-extrusion to contain particles having a specific particle diameter and to have a specific thickness according to each layer, and does not cause the particles to fall off while driving. It relates to a three-layer or more multilayer polyester film excellent in wear resistance.

Saturated linear polyester film represented by polyethylene terephthalate has excellent mechanical properties, heat resistance, weather resistance, electrical insulation, chemical resistance, etc., so it is widely used in the field of packaging, photography, condenser, electrical insulation, magnetic tape, etc. .

In general, in order to use a polyester film smoothly for various purposes, it has to be excellent in winding workability and post-processing processability, and these characteristics have a great influence on the quality of the final product, and especially wear resistance is important among physical properties. One.

In order to improve the wear resistance of the polyester film, a method of containing particles having high hardness is widely used. The high hardness titanium dioxide particles, which have been widely used for fibers, have excellent effects in terms of abrasion resistance, but have excellent particle dispersibility. When this defect is poor and coarse protrusions are formed and used as the base film of the magnetic tape of high density recording, there is a problem that the dropout phenomenon increases.

In addition, a method of imparting fine concavities and convexities to the surface of the film is widely used in order to improve the reactivity of the film. As a method of imparting fine concavities and convexities to the surface of the film, a method of adding inert particles such as calcium carbonate, silica, alumina and kaolin to the reaction system during the production of polyester is most widely used. In addition, there is a method of depositing fine particles in the reaction system by using the residue of a metal compound used as a catalyst during polymerization. For example, Japanese Patent Application Laid-Open No. 34-5144, etc., phosphoric acid or esters thereof in an alkaline earth metal compound. A method of controlling the friction characteristics of a film by adding particles and the like has been proposed. In addition, a method of providing protrusions on the surface of the film by adding externally inert fine particles in the extrusion process during film production is known, but there is a disadvantage in that the wear resistance is not sufficient.

Therefore, the present inventors have continued to research a polyester film having excellent drop resistance and abrasion resistance and an active property of the existing film, and as a result, each polyester containing a certain amount of particles having a specific particle diameter The present invention has been completed by laminating three or more layers of films to produce a polyester film having a multilayer structure.

It is an object of the present invention to provide a polyester film which is excellent in abrasion resistance and diactivity and has improved dropout due to dropping of particles.

According to the above object, in the present invention, in the polyester film having a main repeating unit of ethylene terephthalate or ethylene naphthalate, 0.01 to 3 particles insoluble in polyester having an average particle diameter of 0.5 to 3㎛ with respect to 100 parts by weight of polyester Both the outer layer (A) comprising 0.01 to 3 parts by weight of aluminum hydroxide particles having an average particle diameter of less than 0.001 to 0.5 µm and a thickness of 0.5 to 2 µm, respectively, with respect to the middle layer (B) including the parts by weight and 100 parts by weight of polyester, and The multilayer polyester film of three or more layers which consist of (C) is provided.

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

In the multilayer polyester film according to the present invention, the middle layer has a polyester film containing 0.01 to 3 parts by weight of insoluble particles having a relatively large particle diameter, preferably having an average particle diameter of 0.5 to 3 μm, based on 100 parts by weight of polyester. Is done. Particles insoluble in the polyester used at this time are aluminum hydroxide, calcium phosphate, magnesia, calcium carbonate, silica, kaolin, dolomite, glass spare, fiberglass, mica, talc, alumina, titanium dioxide, geolite, mica, nitride Examples include, but are not limited to, boron, lithium sulfate, thermosetting phenol resin, thermosetting epoxy resin, thermosetting urea resin, benzoguanamine resin, fluorine-based resin, polystyrene or fine powder of silicone resin, and the like. The shape is not limited and may be used in the range that does not adversely affect the object of the present invention.

If the average particle diameter of the particles used in the middle layer is less than 0.5㎛, the size of the irregularities formed on the surface of the polyester film is too small, the activity is poor, if the average particle diameter is larger than 3㎛ the surface of the polyester film Roughening results in poor electronic characteristics. In addition, when the insoluble particles used in the middle layer is less than 0.01 parts by weight with respect to the polyester, the number of irregularities formed on the surface of the film is less, the poor activity, and when used more than 3 parts by weight roughening the film There is.

Both outer layers of the multilayer polyester film according to the present invention contain 0.01 to 3 parts by weight of aluminum hydroxide having an average particle diameter smaller than that of the middle layer, preferably having an average particle diameter of less than 0.001 to 0.5 μm, based on 100 parts by weight of polyester. And the thickness of each layer is to be 0.5 to 2㎛ each. When the average particle diameter of the aluminum hydroxide is less than 0.001㎛, the number of irregularities to be formed is poor, this activity is poor, if the average particle diameter is 0.5㎛ or more, the electronic properties are poor. In addition, when the weight part of the aluminum hydroxide particles used for the polyester is less than 0.01, the number of irregularities formed on the surface of the film is less, the poorer activity is poor, if the weight part is greater than 0.5 there is a problem that the electronic properties are poor. In addition, when the thickness of the formed outer layer is less than 0.5㎛ the insoluble particles of the middle layer protrudes to the outer layer to cause the particles to fall off, which causes dropout phenomenon in the magnetic tape, if the thickness is larger than 2㎛ The particles present do not play a role of forming projections on the film surface.

In order to further enhance the effect of the present invention and to improve affinity with the polymer, the particles used in the present invention may be surface treated with a known surface treating agent.

The manufacturing method of the polyester resin in this invention is not specifically limited, It is preferable to use a conventionally well-known method, but to add the said particle | grains at arbitrary time points before a polymerization reaction is complete | finished.

In addition, the method for producing a polyester film having a multi-layered structure having three or more layers according to the present invention may utilize a conventionally known coextrusion method without being particularly limited. A continuous sheet is produced, for example, by supplying molten polymer to a multi manifold die or feed block die to fix the plate-like molten polymer to a rotating cooling drum and then producing the sheet. Subsequently, the multi-layer film may be manufactured through a single or multi-stage longitudinal drawing and transverse drawing process. In-line coating may be performed between the longitudinal stretching and the transverse stretching to improve the adhesion of the film, the antistatic property, and the corona treatment after the transverse stretching. It is preferable that the multilayer polyester film of this invention has a total thickness of 10-20 micrometers.

Hereinafter, the present invention will be described in more detail based on the following examples. However, the following examples are only for illustrating the present invention, and the scope of the present invention is not limited thereto.

The measuring method used in the following Examples is as follows.

1) Average particle size and particle shape

Fifty sites of the particles were photographed with a scanning electron microscope (50,000 times magnification), and then measured by an image analysis device to obtain an arithmetic mean of the particle size of each site.

2) active activity

Using the TBT-300D, a tape running tester of the Yokohama Systems Research Institute, Japan, the tape is slit in a 1/2 inch width for a driving speed of 3.3 cm / sec and a pull-out force of 30 g, with a fixed angle of 135 °. The driving friction coefficient was measured from the winding tension when the pin (material SUS303) was passed through 90 m using the following equation:

μk = [2.303 / θ] x log [T _i / T _o ]

here,

θ: contact angle between film and guide pin

T _i and T _o : take-up tension and winding tension, respectively

3) wear resistance

At the end of the measurement of the activity, the percentage of the powder on the fixed guide pin was evaluated in the following four steps:

Almost no minute question: ◎

100% buried, 1-5% area of guide pin: ○

100% buried, 5-10% area of guide pin: △

100% buried, more than 10% of the area of the guide pin: ×

Example 1

100 parts by weight of dimethyl terephthalate, 70 parts by weight of ethylene glycol and 0.05 parts by weight of calcium acetate were placed in a reactor and subjected to transesterification for 4 hours. After completion of the reaction, 0.01 parts by weight of aluminum hydroxide having an average particle diameter of 0.4 μm was added to the reactor, followed by addition of 0.06 parts by weight of trimethyl phosphate and 0.04 parts by weight of antimony trioxide, followed by polymerization for 5 hours to obtain a polyester film a. .

On the other hand, the polyester film b was obtained using the same method as the manufacture of the polyester film a, except that 1 part by weight of aluminum hydroxide having an average particle diameter of 2 μm was added.

After drying the prepared polyester films a and b, respectively, the polyester film a becomes the outer layers (A) and (C), and the feed block is installed in a die provided with the feed block so that the polyester film b becomes the middle layer (B). It coextruded under ° C and obtained an amorphous sheet having a three-layer structure. The sheet was then stretched 3.5 times at 90 ° C. in the longitudinal direction and 4.3 times at 110 ° C. in the transverse direction, and then heat-treated at 210 ° C. for 3 seconds to obtain a thickness of the outer layers (A) and (C) of 1 μm and the middle layer ( The 3-layer film whose thickness of B) is 13 micrometers was obtained.

Physical property test results of the three-layer polyester film obtained above are shown in Table 1.

Example 2 to 11

In the manufacture of polyesters a and b, the kind, average particle diameter and content of the particles; And Example 1, except that the thicknesses of the outer layers (A) and (C) and the middle layer (B) in the final three-layer polyester film were changed within the scope of the present invention as shown in Table 1 below. In the same manner as in the three-layer polyester film was prepared.

However, in the case of using the two particles in the preparation of the polyester b was used by mixing so that each mass ratio is 1: 1.

Physical property test results of the obtained film are summarized in Table 1.

Comparative Examples 1 to 7

In the manufacture of polyesters a and b, the kind, average particle diameter and content of the particles; And Example 1, except that the thickness of the outer layers (A) and (C), and the middle layer (B) in the final three-layer polyester film is outside the scope of the present invention as shown in Table 1 below. In the same manner as in the three-layered polyester film was prepared.

However, in the case of using the two particles in the preparation of the polyester b was used by mixing so that each mass ratio is 1: 1.

Physical property test results of the obtained film are summarized in Table 1.

Outer layer (A) and (C) Middle floor (B) Running friction factor Wear resistance Thickness (㎛) Particle name Average particle size (㎛) Content (part by weight) Thickness (㎛) Particle name Average particle size (㎛) Content (part by weight) Example 1 One Al (OH) ₃ 0.4 0.01 13 Al (OH) ₃ 2 One 0.27 ◎ Example 2 One Al (OH) ₃ 0.4 3 13 Al (OH) ₃ 2 One 0.25 ◎ Example 3 One Al (OH) ₃ 0.05 0.01 13 Al (OH) ₃ 2 One 0.28 ◎ Example 4 One Al (OH) ₃ 0.05 3 13 Al (OH) ₃ 2 One 0.28 ◎ Example 5 One Al (OH) ₃ 0.2 2 13 Al (OH) ₃ Calcium Carbonate 3 0.05 0.25 ◎ Example 6 One Al (OH) ₃ 0.2 2 13 Kaolin 3 3 0.24 ◎ Example 7 One Al (OH) ₃ 0.2 2 13 Calcium carbonate 0.7 0.05 0.30 ◎ Example 8 One Al (OH) ₃ 0.2 2 13 Kaolin calcium carbonate 0.7 3 0.29 ◎ Example 9 0.5 Al (OH) ₃ 0.2 2 14 Al (OH) ₃ 2 One 0.26 ◎ Example 10 2 Al (OH) ₃ 0.2 2 11 Al (OH) ₃ 2 One 0.27 ◎ Example 11 0.5 Al (OH) ₃ 0.2 3 14 Al (OH) ₃ Calcium Carbonate 2 One 0.25 ◎ Comparative Example 1 One Al (OH) ₃ 0.6 3 13 Al (OH) ₃ 2 One 0.26 × Comparative Example 2 One Al (OH) ₃ 0.02 0.005 13 Al (OH) ₃ 2 One 0.32 ◎ Comparative Example 3 One Al (OH) ₃ 0.2 2 13 Al (OH) ₃ Calcium Carbonate 5 4 0.24 × Comparative Example 4 One Al (OH) ₃ 0.2 2 13 Kaolin 0.2 0.05 0.35 △ Comparative Example 5 One Al (OH) ₃ 0.2 2 13 Kaolin calcium carbonate 2 4 0.26 △ Comparative Example 6 0.2 Al (OH) ₃ 0.05 3 14.6 Al (OH) ₃ 2 2 0.24 × Comparative Example 7 3 Al (OH) ₃ 0.2 2 9 Al (OH) ₃ Calcium Carbonate 3 3 0.34 ◎

As shown in Table 1, the multi-layered polyester film according to the present invention has excellent activity and wear resistance.

Claims (1)

In a polyester film having a main repeating unit of ethylene terephthalate or ethylene naphthalate, a middle layer (B) containing 0.01 to 3 parts by weight of particles insoluble in polyester having an average particle diameter of 0.5 to 3 µm with respect to 100 parts by weight of polyester 3 layers or more comprising both outer layers (A) and (C) each having from 0.01 to 3 parts by weight of aluminum hydroxide particles having an average particle diameter of less than 0.001 to 0.5 µm and a thickness of 0.5 to 2 µm, respectively, with respect to 100 parts by weight of polyester). Multilayer polyester film.