KR20190082096A - Polyester resin composition for calendering and preparation method of polyester film - Google Patents

Abstract

According to an embodiment of the present invention, a polyester resin composition for calendering comprises a lubricant of which thermal properties are controlled, thereby inhibiting degradation of physical properties of a last film caused by residual components while calender processability is increased. In addition, a polyester film manufactured by using the polyester resin composition for calendering is environment-friendly and has excellent thermal resistance and surface strength, thereby being used as various environment-friendly materials such as a decoration sheet or the like.

Description

TECHNICAL FIELD [0001] The present invention relates to a polyester resin composition for calendering, and a method for producing a polyester film.

The following embodiments relate to a polyester resin composition applied to a calendering process and a method for producing a polyester film using the same. More specifically, embodiments relate to a polyester resin composition blended with an additive capable of enhancing calendar workability, and a method for producing a polyester film usable as an eco-friendly material or the like.

The calendering process is a process of forming a film, a sheet or the like using a calender, that is, a rolling machine in which a plurality of heating rolls are arranged. The calendering process has been mainly used to make films and sheets because it is faster in production speed and easier to process with thinner thickness than extrusion process.

Polyvinyl chloride (PVC) resin, which has been conventionally used in calendering processes, has excellent processability, but is difficult to recycle and causes environmental problems at the time of disposal. In addition, polypropylene (PP) resins are excellent in calendering workability but are not environmentally friendly, and there is a problem that printing and laminating are difficult without corona and primer treatment.

On the other hand, polyethylene terephthalate (PET) resin, which is a typical polyester resin, has excellent physical properties at a price, but calendering workability is poor. Thus, it is known to produce a polyester film using glycol-modified polyethylene terephthalate (PETG) resin so as to have properties suitable for the calendering process (see Korean Patent Laid-Open Publication No. 2014-0109506).

Korean Patent Laid-Open Publication No. 2014-0109506

In order to apply the polyester resin to the calendering step, a glycol component such as 1,4-cyclohexane dimethanol is further introduced, and the polyester resin is prevented from adhering to the metal roll, It is known to add additives.

However, such an additive component exhibits an effect of improving the workability during the calendering process, but there is a problem that after the calendering process is completed, the additive component remains and deteriorates the physical properties of the final film or sheet.

As a result of studies conducted by the present inventors, it has been found that by controlling the thermal properties of an additive for improving calendering workability, the calendering processability can be improved by an additive and the physical properties of the final film can be inhibited from lowering.

Therefore, in the following embodiments, it is intended to provide a polyester resin composition blended with an additive that does not deteriorate the physical properties of the final product while improving processability during the calendering process.

Further, in the following embodiments, it is intended to provide a method for producing a polyester film which is environmentally friendly and has excellent physical properties at a relatively low cost by using the polyester resin composition.

According to one embodiment of the present invention, there is provided a polyester resin comprising a dicarboxylic acid component and a diol component; And a lubricant in an amount of 0.1 part by weight to less than 10 parts by weight based on 100 parts by weight of the polyester resin, wherein the lubricant has a weight reduction ratio of 1 to 20% when maintained at 150 캜 for 100 minutes, 200 Lt; RTI ID = 0.0 >% < / RTI > to 100% by weight, based on the total weight of the composition.

According to another embodiment, there is provided a method for producing a polyester resin composition, comprising the steps of: (1) adding a lubricant to a polyester resin to prepare a polyester resin composition; (2) kneading and gelating the composition; And (3) calendering the gelled composition to form a film, wherein the polyester resin is obtained by polymerizing a dicarboxylic acid component and a diol component, wherein the amount of the lubricant added Is 0.1 to less than 10 parts by weight based on 100 parts by weight of the polyester resin, wherein the lubricant has a weight reduction ratio of 1 to 20% at an initial stage of holding at 150 占 폚 for 100 minutes and maintained at 200 占 폚 for 100 minutes A weight reduction ratio of 20 to 65% based on the initial weight of the polyester film.

Since the calendering polyester resin composition according to the embodiment includes a lubricant with controlled thermal properties, calendering workability is improved and the deterioration of physical properties of the final film due to residual components can be suppressed.

Particularly, since the lubricant has a specific range of weight reduction rate according to the temperature condition applied to the calendering process, it exhibits plasticity and high temperature flowability together with appropriate tackiness and moldability for the metal roll during the calendering process, It does not remain unnecessarily after the calendering step and does not impair the physical properties such as heat resistance and surface strength of the polyester film.

Accordingly, the polyester resin composition according to the above embodiment can be applied to the calendering process and can be made into a polyester film having excellent physical properties at a relatively low cost.

The polyester film thus produced is eco-friendly and has excellent heat resistance and surface strength, and thus can be used as various eco-friendly materials such as decorative sheets.

The following embodiments provide a polyester resin composition for calendering and a method for producing a polyester film using the same.

The following embodiments may be modified into various forms as long as the gist of the invention is not changed.

As used herein, " comprising "means that other elements may be included unless otherwise specified.

The terms first, second, etc. are used herein to describe various components, and the components should not be limited by the term. The terms are used only for the purpose of distinguishing one component from another.

Polyester resin composition for calendering

The polyester resin composition for calendering according to one embodiment includes a polyester resin and a lubricant.

Since the polyester resin composition according to this embodiment contains a lubricant, the lubricant can be eluted (decomposed) at the process temperature while the resin passes through the heated roll, thereby improving the workability.

Specifically, the lubricant improves the melt flowability of the resin in the resin, and can prevent the resin from sticking to a device such as a roll used in the process outside the resin.

Accordingly, the lubricant plays a role in giving the polyester resin composition, in the calendering step, appropriate tackiness and releasability to the metal roll, plasticity and high temperature flowability.

At this time, when the amount of the lubricant eluted at the processing temperature is too small, the molding process is difficult due to adhesion, and the resin stays on the roll for a long time and deteriorates.

On the other hand, if the amount of the lubricant eluted at the processing temperature is too high, the lubricant is exhausted before the entire process is completed, so that the lubricant is not sufficient at the final stage of the process, The appearance of the product surface becomes poor due to the generation of bubbles due to elution.

Generally, the chips are gelled in the calendering process and then introduced into the processing rolls at a temperature above the glass transition temperature. Thereafter, the substrate is quenched at room temperature through a temperature elevation and calendaring process, and is subjected to embossing roll processing depending on the application.

In such a calendering process, it is necessary to uniformly affect the lubricant from the gelation to the final stage. For this purpose, it is necessary to control the elution amount (decomposition amount) of the lubricant for each section according to the process temperature.

That is, in the calendering process, the utility of the lubricant can be significantly enhanced by controlling the thermal properties of the lubricant depending on the temperature, rather than the type and content of the lubricant.

According to this embodiment, the lubricant has a specific range of weight reduction rates depending on the temperature conditions.

As an example, the lubricant has a weight reduction rate of 1 to 20% relative to the initial value at 150 DEG C for 100 minutes. Specifically, the lubricant may have a weight reduction rate of 2 to 15% or 2 to 10% at an initial stage of maintaining the lubricant at 150 DEG C for 100 minutes. When it is within the above-mentioned preferable range, it can be advantageous from the viewpoint of improving the resin flowability without fusion at the surface of the working roll.

As another example, the lubricant has a weight reduction rate of 20 to 65% compared to the initial value at 200 占 폚 for 100 minutes. Specifically, the lubricant may have a weight reduction rate of 25 to 65% or 35 to 65% at the initial stage at 200 ° C for 100 minutes. Within the above-mentioned preferable range, carbonization on the surface of the working roll is not generated, and it may be advantageous in terms of reduction of frictional force between the sheet and the roll and releasability.

As another example, the lubricant may have a weight loss rate of 30% to 70% at an initial temperature rise from 30 ° C to 350 ° C at a rate of 20 ° C / minute. Specifically, the lubricant may have a weight reduction rate of 35 to 65% or 40 to 65% at an initial temperature rise rate of 30 ° C to 350 ° C at a rate of 20 ° C / minute. Within the weight reduction rate range, it may be advantageous in view of sheet releasability and bubble generation prevention.

As another example, the lubricant may have a weight loss rate of 30 to 70%, 35 to 65%, or 40 to 65% by weight at an initial heating rate of 30 ° C to 300 ° C at a rate of 20 ° C / minute.

The type of the lubricant is not particularly limited as long as the foregoing thermal characteristics are satisfied.

Specifically, if the lubricant has a weight reduction ratio of 1 to 20% at 150 ° C. and 100 minutes under isothermal TGA analysis and a weight reduction ratio of 20 to 65% at 200 ° C. and 100 minutes, Can be selected independently.

In addition, when the temperature is elevated from 30 ° C to 350 ° C at a rate of 20 ° C / minute in the TGA analysis, a weight reduction rate of 30 to 70% may be considered in selecting the lubricant.

The content of the lubricant is not less than 0.1 parts by weight and less than 10 parts by weight based on 100 parts by weight of the polyester resin.

Specifically, the content of the lubricant is 0.1 to 5 parts by weight, 1 to 5 parts by weight, 0.1 to 3 parts by weight, 0.1 to 2 parts by weight, 3 to 5 parts by weight, or 5 to 5 parts by weight based on 100 parts by weight of the polyester resin. But it is not limited thereto.

When the content of the lubricant is within the range, the improvement in calendaring workability is maximized, and excessive lubricant can be prevented from deteriorating the physical properties.

As another example, when two or more kinds of lubricants are used in combination, it may be more advantageous to satisfy both the flowability inside the resin and the releasability outside the resin.

On the other hand, when two or more kinds of lubricants are used in combination, it is preferable to take into account the respective thermal characteristics of each lubricant depending on the process temperature range.

The lubricant may be composed of two or more lubricants having different thermal properties.

Specifically, the lubricant may include a first lubricant and a second lubricant.

The weight ratio of the first lubricant and the second lubricant may range from 1: 2 to 2: 1. More specifically, the weight ratio of the first lubricant and the second lubricant may range from 1: 1.6 to 1.8: 1.

The first lubricant and the second lubricant may have different thermal properties.

For example, when the first lubricant is maintained at 150 DEG C for 100 minutes, the weight loss rate is 1 to 12% relative to the initial value, and when the second lubricant is maintained at 150 DEG C for 100 minutes, Lt; / RTI >

As another example, when the first lubricant is maintained at 200 DEG C for 100 minutes, the weight loss rate is 20 to 45% relative to the initial value, and when the second lubricant is maintained at 200 DEG C for 100 minutes, the initial lubricant weight is 40 to 80% Reduction rate.

The types of the first lubricant and the second lubricant are not particularly limited as long as the foregoing thermal characteristics are satisfied. In addition, the first lubricant may be a combination of two or more lubricants if the above-mentioned thermal characteristics are satisfied. Likewise, combinations of two or more kinds of lubricants may be possible if the thermal properties of the second slide system are satisfied.

In addition, the first and second lubricants may function differently in the calendering process. Although these functions are not particularly limited, for example, the first lubricant can improve the flowability of the resin composition in the calendering step, and the second lubricant can improve the releasability to the metal roll.

The polyester resin is obtained by polymerizing a dicarboxylic acid component and a diol component.

That is, the polyester resin includes a dicarboxylic acid component and a diol component as monomers.

Specifically, the polyester resin may have a repeating unit derived from the dicarboxylic acid component and the diol component polymerized thereon.

Wherein the dicarboxylic acid component is selected from the group consisting of terephthalic acid (TPA), isophthalic acid (IPA), naphthalene dicarboxylic acid (NDC), cyclohexanedicarboxylic acid (CHDA), succinic acid, glutaric acid, orthophthalic acid, Azelaic acid, sebacic acid, decanedicarboxylic acid, 2,5-furandicarboxylic acid, 2,5-thiopendicarboxylic acid, 2,7-naphthalenedicarboxylic acid, 4,4'- Derivatives thereof, or combinations thereof.

Specifically, the dicarboxylic acid component may include, but is not limited to, terephthalic acid, isophthalic acid, naphthalene dicarboxylic acid, cyclohexanedicarboxylic acid, or a combination thereof. More specifically, the dicarboxylic acid component may include, but is not limited to, terephthalic acid and / or isophthalic acid.

The diol component may include a linear or branched aliphatic diol, an alicyclic diol, an aromatic diol, or the like.

For example, the linear or branched aliphatic diol is selected from the group consisting of ethylene glycol (EG), diethylene glycol (DEG), neopentyl glycol, 1,3-propanediol, 1,2-octanediol, , 2,3-butanediol, 1,3-butanediol, 1,4-butanediol, 1,5-pentanediol, 2-butyl- Pentanediol, 1,6-hexanediol, 1,6-hexanediol, 1,6-hexanediol, 1,6-hexanediol, Methyl-1,5-hexanediol, 2-ethyl-3-ethyl-1,5-hexanediol, 1,7-heptanediol, , 2-ethyl-3-ethyl-1,6-heptanediol, 1,8-octanediol, 1,9-nonanediol, 1,10-decanediol and the like or any combination thereof, But is not limited thereto.

In addition, the alicyclic diol may include cyclohexane dimethanol (CHDM), isosorbide, 2,2,4,4-tetramethyl-1,3-cyclobutanediol (CBDO) But is not limited thereto.

Specifically, the diol component may include, but is not limited to, ethylene glycol, diethylene glycol, neopentyl glycol, cyclohexanedicarboxylic acid, or combinations thereof.

When a film or a sheet is produced by calendering using a polyester resin containing the linear or branched aliphatic diol, since the packing is well performed, the film can have excellent chemical resistance and surface strength.

When a film or a sheet is produced by calendering a polyester resin containing the alicyclic diol or aromatic diol, the copolymer can be chemically and stably bonded to improve the impact strength, heat resistance, and the like.

By way of example, the diol component may comprise from 10 to 90 mole%, from 20 to 90 mole%, from 20 to 85 mole%, from 23 to 84 mole%, or from 24 to 83 mole% neopentyl glycol or Cyclohexanedimethanol. ≪ / RTI >

The dicarboxylic acid component comprises an aromatic dicarboxylic acid, and the diol component is (i) a branched aliphatic diol or an alicyclic Diols, and (ii) linear aliphatic diols.

Specifically, the dicarboxylic acid component includes at least one of terephthalic acid and isophthalic acid, and the diol component may include (i) at least one of neopentyl glycol and cyclohexane dimethanol, and (ii) ethylene glycol have.

The polyester resin composition according to this embodiment may further contain components such as a polymerization catalyst, a stabilizer, and a coloring agent in addition to the polyester resin and the lubricant.

Such polymerization catalysts, stabilizers and coloring agents may be added to the product of the esterification reaction or transesterification reaction prior to the initiation of the polymerization reaction and added to the mixed slurry containing the dicarboxylic acid and the diol compound before the esterification reaction And may be added in the middle of the esterification reaction step.

As the polymerization catalyst, an antimony compound, a titanium compound, a germanium compound, an aluminum compound, or a mixture of such compounds may be used. As the antimony compound, antimony trioxide, antimony acetate, antimony glycolate and the like can be used. As the titanium compound, tetraethyl titanate, tetrapropyl titanate, tetrabutyl titanate, titanium dioxide, titanium dioxide / Silicon dioxide copolymer, and the like can be used. As the germanium-based compound, germanium dioxide, germanium acetate, germanium glycolate and the like can be used.

Phosphoric acid, trimethyl phosphate, triethyl phosphate and other phosphorus compounds may be used as the stabilizer, and the amount of the stabilizer may be 10 to 100 ppm based on the weight of the phosphorus (P) element, based on the weight of the final polymer. If the addition amount of the stabilizer is less than 10 ppm, the stabilization effect is insignificant and yellowing of the final polymer may occur. If the addition amount of the stabilizer exceeds 100 ppm, the activity of the polymerization catalyst may be inhibited, which may be disadvantageous for obtaining a polymer with high polymerization degree.

The coloring agent is added to improve the hue of the polymer. The coloring agent may be cobalt acetate, a cobalt propionate metal salt coloring agent and a coloring agent as a dye component, and the amount thereof may be 0 to 100 ppm based on the weight of the final polymer .

The intrinsic viscosity (IV) of the polyester resin may be 0.6 to 3.0 dl / g. Specifically, the polyester resin has an intrinsic viscosity (IV) of 0.6 to 2.5 dl / g, 0.6 to 2.0 dl / g, 0.6 to 1.5 dl / g, 0.6 to 1.0 dl / g, 0.62 to 1.5 dl / To 1.2 dl / g, or 0.66 to 0.85 dl / g, but is not limited thereto.

When the intrinsic viscosity of the polyester resin is in the above range, calendering workability is excellent, the kinematic viscosity retention ratio in the calendering step is excellent, and the thickness uniformity of the sheet and film is excellent.

Method for producing polyester resin composition

The method for producing the polyester resin composition comprises the steps of: (1a) mixing a dicarboxylic acid component and a diol component to effect an esterification reaction; (1b) a polycondensation reaction of the obtained esterification reaction product to obtain a polyester resin; And (1c) adding a lubricant to the polyester resin to prepare a polyester resin composition.

The dicarboxylic acid component and the diol component used in the esterification step of step (1a) are as exemplified above.

At this time, it is preferable that the diol component is overdosed in an amount of 1.05 to 3.0 moles, 1.05 to 2.0 moles, or 1.05 to 1.5 moles, relative to 1 mole of the dicarboxylic acid component. When the above ratio is blended, it is advantageous that the esterification reaction stably proceeds to form a sufficient ester oligomer.

On the other hand, it is not preferable to add an acrylic compound as a raw material of the polyester resin because it can generate unmelted gel.

The polycondensation step of step (1b) may be carried out at a temperature of 230 to 270 ° C and a pressure of 0.1 to 3.0 kg / cm ² . More specifically, the polycondensation step can be carried out at a temperature of 240 to 295 ° C and a pressure of 0.2 to 2.9 kg / cm ² .

The polycondensation step is carried out in the presence of a polycondensation catalyst, a stabilizer, a vehicle, a dispersing agent, an antiblocking agent, an electrostatic agent, an antistatic agent, an antioxidant, a heat stabilizer, a photoinitiator or any combination thereof conventionally known to those skilled in the art And may be included within a range that does not impair the effect of the resin composition.

As an example, the polycondensation step may be carried out in the presence of a polycondensation catalyst.

The polycondensation catalyst may include, but is not limited to, alkali metals, alkaline earth metals, antimony, titanium, manganese, cobalt, cerium, germanium, or any combination thereof. Preferably, an antimony compound may be used as the polycondensation catalyst.

The polycondensation catalyst may be used in an amount of 50 to 1,000 ppm, 50 to 500 ppm, or 50 to 400 ppm based on the total weight of the polyester resin. In the content range of the polycondensation catalyst, it may be advantageous to increase the polycondensation reaction rate, suppress the side reaction, and increase transparency.

As another example, the polycondensation step can be carried out in the presence of a stabilizer.

The stabilizer may include a phosphorus stabilizer. The phosphorus stabilizer may include, but is not limited to, phosphoric acid, trimethyl phosphate, triethyl phosphate, triphenyl phosphate, triethyl phosphonoacetate, hindered phenol, or any combination thereof. The stabilizer may be used in an amount of 3,000 ppm or less, 1 to 2,500 ppm, 1 to 1500 ppm, or 1 to 1000 ppm based on the total weight of the polyester resin.

As another example, the polycondensation step may be carried out in the presence of a vehicle.

The vehicle may include, but is not limited to, an organic vehicle, an inorganic vehicle, a dye, or a combination thereof. Specifically, the vehicle may be cobalt acetate, cobalt propionate, an inorganic vehicle, or any combination thereof. The vehicle may be used in an amount of 1 to 500 ppm, or 1 to 200 ppm, based on the total weight of the polyester resin.

Thereafter, the polyester resin and the lubricant are mixed to prepare a polyester resin composition.

At this time, the kind and content of the lubricant added are as described above.

Method for producing polyester film

A method of making a polyester film according to one embodiment comprises:

(1) preparing a composition by mixing a polyester resin and a lubricant;

(2) kneading and gelating the composition; And

(3) calendering the gelled composition to form a film.

Each step will be described in detail below.

In the step (1), a lubricant is added to the polyester resin to prepare a composition.

The polyester resin used herein is obtained by polymerizing a dicarboxylic acid component and a diol component as described above.

Specifically, the dicarboxylic acid component comprises terephthalic acid, isophthalic acid, naphthalene dicarboxylic acid, cyclohexanedicarboxylic acid, or a combination thereof, and the diol component is selected from the group consisting of ethylene glycol, diethylene glycol, neopentyl glycol, Hexane dimethanol, or a combination thereof. In this case, the diol component may contain at least one of neopentyl glycol and cyclohexane dimethanol in an amount of 30 to 90 mol% in total.

The lubricant may be added in an amount of 0.1 part by weight to less than 10 parts by weight based on 100 parts by weight of the polyester resin.

As described above, the lubricant has a weight reduction rate of 1 to 20% at an initial stage of maintaining at 150 ° C for 100 minutes, and a weight reduction rate of 20 to 65% at an initial stage of maintaining at 200 ° C for 100 minutes.

In addition, the lubricant may have a weight reduction rate of 30 to 70% at an initial temperature rise at a rate of 20 ° C / minute from 30 ° C to 350 ° C.

In addition, the lubricant may have a weight reduction rate of 30 to 70% at an initial temperature rise rate of 350 ° C to 500 ° C at a rate of 20 ° C / minute.

According to the embodiment, the type of the lubricant is not particularly limited as long as the above-mentioned thermal characteristics are satisfied.

For example, the lubricant may be at least one selected from the group consisting of fatty acids, fatty acid salts, metal salts of organic acids, fatty acid esters, amides, hydrocarbon waxes, ester waxes, phosphoric acid esters, polyolefin waxes, modified polyolefin waxes, talc and acrylic copolymers , And more preferably two or more, but is not limited thereto.

Specifically, the lubricant may be at least one member selected from the group consisting of stearic acid, palmitic acid, montan wax, roxiol, PE wax, paraffin wax, cetyl ester, glyceryl distearate, and modified compounds thereof .

In addition, the lubricant may be composed of two or more kinds, and may include, for example, a first lubricant and a second lubricant. The weight ratio of the first lubricant and the second lubricant may range from 1: 2 to 2: 1.

Also, when the first lubricant is maintained at 150 ° C for 100 minutes, the weight loss rate is 1 to 12% relative to the initial value, and when the second lubricant is maintained at 150 ° C for 100 minutes, the weight loss rate is 10 to 25% Lt; / RTI >

A high speed mixer (e.g., a Henshell Mixer) may be used to mix the polyester resin and additives. For example, the polyester resin composition may be pelletized, and the pelletized polyester resin may be put into a high-speed mixer and mixed for 30 to 300 seconds at a temperature range of 20 to 40 ° C.

In the step (2), the polyester resin composition obtained above is kneaded and gelled.

The step of kneading and gelling the composition includes: (2a) a step of gelling by using a planetary extruder or Banbury intensive mixer; (2b) a step of homogenizing using a mixing roll; And (2c) a step of homogenizing using a warming roll.

As another example, the steps (2a), (2b), and (2c) may be sequentially performed in the gelling step.

The temperature condition in the step (a) may be in the range of 180 to 230 ° C in the step (2a), 90 to 130 ° C in the step (2b), and 90 to 130 ° C in the step (2c) But is not limited thereto.

In the step (3), the gelled composition is calendered to form a film.

In the calendering step, a plurality of calender rolls can be used at a temperature ranging from 145 to 210 ° C at a rate of 10 to 120 m / min. However, the present invention is not limited thereto.

Further, in the calendering process, it may further include taking off the film from the calender roll using take-off rolls, and adjusting the thickness and smoothness of the film. Such peeling of the film and adjustment of its thickness and smoothness can be performed at a temperature of 120 to 170 ° C at a rate of 30 to 120 m / min, but the present invention is not limited thereto.

The previously calendered film may be subjected to a further surface treatment step.

For example, the surface treatment may be carried out by embossing or the like.

The embossing process refers to a process of forming a convexly convex shape on the surface of a film by heat and pressure.

For example, the embossing may be performed at a temperature range of 30 to 90 DEG C using an embossing unit. At this time, the surface treatment rate of the film may be 30 to 120 m / min, but is not limited thereto.

By passing through the surface treatment step, the windability can be improved and the matte can be realized.

The calendared film is then cooled.

If the above embossing has been performed, peeling of the film from the embossing unit using the annealing roll is performed first.

Such peeling can be carried out at a temperature of 5 to 80 캜 at a rate of 40 to 130 m / min, but is not limited thereto.

The cooling of the calendered film can be carried out at a rate of 30 to 120 m / min in a temperature range of -5 ° C to 50 ° C using a cooling roll.

The width of the film produced using a side trimming device can then be cut and the thickness of the film produced using a thickness gauge can be measured.

The cooled film can then be wound. For example, the cooled film may be wound at a speed of 55 to 95 m / min using a winder, but the present invention is not limited thereto.

Polyester film

The polyester film produced by the method according to the above embodiment is environmentally friendly and has excellent surface hardness, optical properties and heat resistance.

The surface hardness of the film may be from B to HB.

The surface hardness can be measured by an electric pencil hardness tester method, and can be obtained, for example, by measuring pencil (6B to 9H) manufactured by Mitsubishi Corporation at 45 degrees at the same load (200 g) and speed.

The transparency of the polyester film may be 30 to 75%, more specifically 32 to 73%, 33 to 70%, 35 to 70%, 35 to 68%, or 40 to 65% But is not limited thereto.

The haze of the film may be 0 to 20%, more specifically 0 to 15%, 2 to 15%, or 2 to 13%, but is not limited thereto.

The haze is a measure of the transparency and visibility of the film. The haze of the film satisfies the above range, which means that even if additional lamination such as a printing layer occurs, the optical property of the film is not lowered and the product utilization is excellent.

The above contents will be described in more detail by the following examples. However, the following examples are for illustrative purposes only and are not intended to limit the scope of the examples.

Examples 1 to 7 and Comparative Examples 1 to 5

For the production of polyester resin, a diol component and a dicarboxylic acid component were added to a 2500 L reactor equipped with a stirrer and an outlet condenser so that the final polymer amount was 2,000 kg. Thereafter, the internal pressure of the reactor was raised to 2.0 kg / cm < 2 > using nitrogen gas, and the reaction was performed while raising the temperature of the reactor to 265 DEG C. [ At this time, the reaction product was transferred to a polycondensation reactor equipped with a stirrer, a cooling condenser and a vacuum system.

Antimony triglycolate as a metal polycondensation catalyst was added to the obtained esterification reaction product so that the amount of antimony triglycolate became 300 ppm based on the amount of the antimony element, and triethyl phosphate (TEP) as a phosphorus stabilizer was added so as to be 500 ppm based on the phosphorus content Respectively. After that, low vacuum reaction was performed for 40 minutes while raising the internal temperature and pressure of the reactor to 285 ~ 290 ° C and 50 mmHg. Thereafter, the diol component was discharged to the outside, and the pressure was gradually reduced to 0.1 mmHg to conduct the reaction under the high vacuum to the maximum power value.

The polyester resin obtained in the polycondensation reaction was discharged and cut into chips. A lubricant was added to the polyester resin to prepare a composition. The composition was extruded on average at 200 ° C, kneaded, gelled and calendered to produce a 0.2 mm thick film.

(TPA) and / or isophthalic acid (IPA) were used as the dicarboxylic acid component and ethylene glycol (EG), neopentyl glycol (NPG) and / or cyclohexanedimethanol ), And lubricants selected from stearic acid, palmitic acid, montan wax, and roxiol were used in combination as a lubricant.

The dicarboxylic acid component, the diol component and the kind of the lubricant and their contents (compounding ratio in the final composition) are shown in Table 1 below.

Test Example

The respective polyester resins, polyester resin compositions and polyester films prepared in the above Examples and Comparative Examples were evaluated as follows, and the results are shown in Tables 1 and 2 below.

(1) Intrinsic viscosity (IV)

After dissolving the polyester resin in ortho-chlorophenol at 100 占 폚, the falling time of the sample was measured with an Ostwald viscometer in a thermostatic chamber at 35 占 폚 to measure intrinsic viscosity (IV).

(2) Process evaluation

The following items were evaluated while performing the calendering process using the polyester resin composition.

- Sheet Formulation: Evaluation was made as to whether the sheet was formed well by the calendering process.

  O: excellent sheet formation,?: Sheet formation normal, X: poor sheet formation

- Dissimilarity: During the process, it was evaluated whether the sheet was released well without sticking to the working roll.

  O: excellent mold releasing property,?: Releasing property moderate, X: poor mold releasing property

- Surface bubbles: It was evaluated whether bubbles occurred on the sheet surface after the process.

  O: a large number of bubbles, △: bubbles slightly normal, X: no bubbles

(3) Lubricant thermal properties

The initial weight loss rate at 150 ° C and 200 ° C was measured by isothermal TGA method (delay of 100 minutes) for the lubricant, and the results are shown in Table 1.

The initial weight loss rate of the lubricant was measured at a temperature of 30 to 350 DEG C by a temperature elevation TGA method (20 DEG C / min) and is shown in Table 1.

As shown in Table 1, in Examples 1 to 7 using the lubricant having the thermal properties (weight loss rate per temperature) according to the examples, the sheet production, the releasability and the surface bubbles were extremely excellent. On the other hand, in the case of Comparative Examples 2 to 5 using a lubricant not belonging to the thermal property range of the example, the process evaluation result was not good, and in Comparative Example 1, the composition of the polyester resin was not satisfied and the sheet could not be produced.

Claims (11)

A polyester resin in which a dicarboxylic acid component and a diol component are polymerized; And
A composition comprising from 0.1 part by weight to less than 10 parts by weight of a lubricant based on 100 parts by weight of the polyester resin,
The lubricant
When it is maintained at 150 DEG C for 100 minutes, it has a weight reduction rate of 1 to 20%
And having a weight reduction ratio of 20 to 65% at an initial stage of holding at 200 DEG C for 100 minutes.
The method according to claim 1,
The lubricant
When maintained at 150 ° C for 100 minutes, the weight reduction rate was 2 to 15%
And a weight reduction rate of 25 to 65% at the initial stage of holding at 200 DEG C for 100 minutes,
A polyester resin composition for calendering.
The method according to claim 1,
Wherein the composition contains the lubricant in an amount of 0.1 to 5 parts by weight based on 100 parts by weight of the polyester resin.
The method according to claim 1,
Wherein the lubricant comprises a combination of a first lubricant and a second lubricant,
Wherein the weight ratio of the first lubricant and the second lubricant is in the range of 1: 2 to 2: 1.
5. The method of claim 4,
When the first lubricant is maintained at 150 DEG C for 100 minutes, the weight of the first lubricant is 1 to 12%
Wherein the second lubricant has a weight reduction ratio of 10 to 25% at an initial stage at 150 DEG C for 100 minutes.
6. The method of claim 5,
When the first lubricant was maintained at 200 DEG C for 100 minutes, the weight loss rate of the first lubricant was 20 to 45%
Wherein the second lubricant has a weight loss rate of 40 to 80% when maintained at 200 DEG C for 100 minutes.
The method according to claim 1,
Wherein the dicarboxylic acid component comprises terephthalic acid, isophthalic acid, naphthalene dicarboxylic acid, cyclohexanedicarboxylic acid, or a combination thereof,
Wherein the diol component comprises ethylene glycol, diethylene glycol, neopentyl glycol, cyclohexanedimethanol, or a combination thereof.
8. The method of claim 7,
Wherein the diol component comprises at least one of neopentyl glycol and cyclohexanedimethanol in an amount of 30 to 90 mol% in total.
The method according to claim 1,
Wherein the polyester resin has an intrinsic viscosity (IV) of 0.6 to 1.0 dl / g.
The method according to claim 1,
Wherein the lubricant comprises at least one selected from the group consisting of fatty acid, fatty acid salt, metal salt of organic acid, fatty acid ester, amide, hydrocarbon wax, ester wax, phosphoric ester, polyolefin wax, modified polyolefin wax, talc and acrylic copolymer. A polyester resin composition for calendering.
(1) preparing a polyester resin composition by adding a lubricant to a polyester resin;
(2) kneading and gelating the composition; And
(3) calendering the gelled composition to form a film, the method comprising:
Wherein the polyester resin is obtained by polymerizing a dicarboxylic acid component and a diol component,
The addition amount of the lubricant is not less than 0.1 parts by weight and less than 10 parts by weight based on 100 parts by weight of the polyester resin,
Here,
When it is maintained at 150 DEG C for 100 minutes, it has a weight reduction rate of 1 to 20%
Wherein the polyester film has a weight loss rate of 20 to 65% at an initial stage of holding at 200 DEG C for 100 minutes.