KR102144039B1 - Polyester resin composition for calendering and preparation method of polyester film - Google Patents

Abstract

Since the polyester resin composition for calendering according to an embodiment includes a lubricant with controlled thermal properties, calendering processability is improved and a decrease in physical properties of the final film due to residual components may be suppressed. In addition, the polyester film manufactured by using the polyester resin composition for calendering is environmentally friendly and has excellent heat resistance and surface strength, and thus can be used as various eco-friendly materials such as decor sheets.

Description

A polyester resin composition for calendering and a method for producing a polyester film {POLYESTER RESIN COMPOSITION FOR CALENDERING AND PREPARATION METHOD OF POLYESTER FILM}

The following embodiments relate to a polyester resin composition applied to a calendering process and a method of manufacturing a polyester film using the same. More specifically, embodiments relate to a polyester resin composition blended with an additive that can increase calender processability, and a method of manufacturing a polyester film that can be used as an eco-friendly material by using the same.

The calendering process is a process of forming films, sheets, etc. using a calender, that is, a rolling machine in which several heating rolls are arranged. The calendering process has been mainly used to make films and sheets because the production speed is faster than the extrusion process and it is easy to process with a thin thickness.

Polyvinyl chloride (PVC) resin, which has been mainly used in the calendering process, has excellent processability, but is difficult to recycle and causes environmental problems during disposal. In addition, polypropylene (PP) resin has excellent calender processability, but is not eco-friendly, and printing and lamination 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 for the price, but has poor calender processability. Accordingly, it is known to manufacture a polyester film using a glycol-modified polyethylene terephthalate (PETG) resin to have properties suitable for application in a calendering process (see Korean Patent Publication No. 2014-0109506).

Republic of Korea Patent Publication No. 2014-0109506

In order to apply the polyester resin to the calendering process, with the addition of a glycol component such as 1,4-cyclohexanedimethanol, to prevent the polyester resin from sticking to the metal roll and to improve high temperature flowability. It is known to blend additives.

However, such an additive component exerts an effect of enhancing workability during the calendering process, but remains after the calendering process is completed and has a problem of lowering the physical properties of the final film or sheet.

Accordingly, as a result of research by the present inventors, it was found that by controlling the thermal properties of the additive for enhancing the calender processability, the calender processability can be improved by the additive and the deterioration of the physical properties of the final film can be suppressed.

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

In addition, in the following embodiments, it is intended to provide a method of manufacturing a polyester film having environmentally friendly and excellent physical properties at a relatively low cost by using the polyester resin composition.

According to one embodiment for achieving the above object, a dicarboxylic acid component and a diol component is polymerized polyester resin; And 0.1 parts by weight or more to less than 10 parts by weight of a lubricant based on 100 parts by weight of the polyester resin, wherein the lubricant has a weight reduction ratio of 1 to 20% compared to the initial stage when maintained at 150° C. for 100 minutes, and 200 There is provided a polyester resin composition for calendering, which has a weight reduction ratio of 20 to 65% compared to the initial period when maintained at °C for 100 minutes.

According to another embodiment, (1) preparing a polyester resin composition by adding a lubricant to the polyester resin; (2) kneading the composition to form a gel (gelation); And (3) calendering the gelled composition to form a film, wherein the polyester resin is obtained by polymerization of a dicarboxylic acid component and a diol component, and the amount of the lubricant added It is 0.1 parts by weight or more to less than 10 parts by weight based on 100 parts by weight of the polyester resin, where the lubricant has a weight reduction rate of 1 to 20% compared to the initial period when maintained at 150° C. for 100 minutes, and maintained at 200° C. for 100 minutes At the time, a method of manufacturing a polyester film is provided having a weight reduction ratio of 20 to 65% compared to the initial stage.

Since the polyester resin composition for calendering according to the above embodiment includes a lubricant with controlled thermal properties, calendering processability is improved and a decrease in physical properties of the final film due to residual components may be suppressed.

In particular, since the lubricant has a weight reduction rate in a specific range depending on the temperature conditions applied to the calendering process, while the calendering process is in progress, it exhibits plasticity and high-temperature flow properties along with appropriate adhesion and releasability to the metal roll, Since it does not remain unnecessarily after the calendering process, physical properties such as heat resistance and surface strength of the polyester film are not impaired.

Accordingly, the polyester resin composition according to the embodiment may be applied to a calendering process to be prepared as a polyester film having excellent physical properties at a relatively low cost.

In addition, the polyester film prepared in this way is eco-friendly and has excellent heat resistance and surface strength, so it can be used as various eco-friendly materials such as decor sheets.

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

The following embodiments may be modified in various forms unless the gist of the invention is changed.

In the present specification, "including" means that other components may be further included unless otherwise specified.

In the present specification, terms such as first and second are used to describe various components, and the components should not be limited by the terms. The above terms are used only for the purpose of distinguishing one component into another component.

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 the embodiment includes a lubricant, the lubricant is eluted (decomposed) at a corresponding process temperature while the resin passes through the heated roll, thereby improving processability.

Specifically, the lubricant improves the melt flowability of the resin inside the resin and prevents adhesion to devices such as rolls used in the process outside the resin.

Accordingly, the lubricant serves to impart plasticity and high-temperature flowability to the polyester resin composition in the calendering process, along with appropriate adhesion and releasability to the metal roll.

At this time, if the amount of the lubricant eluting at the processing temperature is too small, molding processing is difficult due to adhesion and the resin stays on the roll for a long time, resulting in a problem of deterioration.

Conversely, if the amount of lubricant eluting at the processing temperature is too large, the lubricant is exhausted before the entire process is completed, and thus the lubricant is insufficient at the last stage of the process, resulting in breakage due to lower roll releasability. The appearance of the product surface is deteriorated due to the occurrence of bubbles due to elution.

In general, the chips are gelled in the calendering process and then added to the processing roll at a temperature higher than the glass transition temperature. Thereafter, it is quenched at room temperature through a heating and calendering process, and processed by an embossing roll depending on the application.

In such a calendering process, the lubricant should be affected evenly from gelation to the final stage, and for this, 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, by controlling the thermal properties of the lubricant according to temperature rather than the type and content of the lubricant, the effectiveness of the lubricant can be remarkably increased.

According to the embodiment, the lubricant has a weight reduction rate in a specific range according to temperature conditions.

As an example, the lubricant has a weight reduction rate of 1 to 20% compared to the initial period when maintained at 150° C. for 100 minutes. Specifically, the lubricant may have a weight reduction ratio of 2 to 15% or 2 to 10% compared to the initial period when maintained at 150° C. for 100 minutes. When it is within the above preferred range, it may be advantageous in terms of improving resin flowability without fusion on the surface of the processing roll.

As another example, the lubricant has a weight reduction ratio of 20 to 65% compared to the initial period when maintained at 200° C. for 100 minutes. Specifically, the lubricant may have a weight reduction ratio of 25 to 65% or 35 to 65% compared to the initial period when maintained at 200°C for 100 minutes. When it is within the above preferred range, carbonization does not occur on the surface of the processing roll, and it may be advantageous in terms of reducing frictional force between the sheet and the roll and releasability.

As another example, the lubricant may have a weight reduction ratio of 30 to 70% compared to the initial period when the temperature is raised from 30°C to 350°C at a rate of 20°C/min. Specifically, the lubricant may have a weight reduction rate of 35 to 65% or 40 to 65% compared to the initial period when the temperature is raised from 30°C to 350°C at a rate of 20°C/min. When it is within the range of the weight reduction ratio, it may be advantageous in terms of sheet releasability and prevention of bubble generation.

As another example, the lubricant may have a weight reduction ratio of 30 to 70%, 35 to 65%, or 40 to 65% compared to the initial period when the temperature is raised from 30°C to 300°C at a rate of 20°C/min.

The lubricant is not particularly limited to its type as long as it satisfies the above thermal properties.

Specifically, if the weight reduction rate is in the range of 1 to 20% in the condition of 150°C and 100 minutes in the isothermal TGA analysis, and the chemical structure and type of the lubricant satisfying the range of 20 to 65% in the range of 200°C and 100 minutes Can be chosen regardless.

In addition, when the temperature rises TGA analysis reaches from 30°C to 350°C at a rate of 20°C/min, it may be considered in the selection of the lubricant that the weight reduction rate satisfies the range of 30 to 70%.

The content of the lubricant is 0.1 parts by weight or more 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. It may be 10 parts by weight, but is not limited thereto.

When it is within the range of the amount of the lubricant, it is possible to prevent an excessive amount of lubricant from impairing physical properties while maximizing calender processability.

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

On the other hand, when two or more types of lubricants are used in combination, it is good to consider the thermal characteristics of each lubricant itself according to the process temperature section.

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.

In this case, 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.

As an example, when the first lubricant is maintained at 150°C for 100 minutes, the weight reduction rate is 1 to 12% compared to the initial period, and when the second lubricant is maintained at 150°C for 100 minutes, the weight reduction rate is 10 to 25% compared to the initial stage. Can have

As another example, when the first lubricant is maintained at 200°C for 100 minutes, the weight reduction ratio is 20 to 45% compared to the initial stage, and when the second lubricant is maintained at 200°C for 100 minutes, the weight of the first lubricant is 40 to 80% It can have a reduction rate.

The first lubricant and the second lubricant are not particularly limited to the type as long as only the thermal properties described above are satisfied. In addition, the first lubricant may be a combination of two or more lubricants provided that only the thermal properties described above are satisfied. Likewise, a combination of two or more types of lubricants is possible as long as the second lubricant satisfies only the thermal characteristics described above.

In addition, the first lubricant and the second lubricant may perform different functions in a calendering process. Although these functions are not particularly limited, for example, the first lubricant may improve the flowability of the resin composition in the calendering process, and the second lubricant may improve the releasability of the metal roll.

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

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

Specifically, the polyester resin may have a dicarboxylic acid component and a diol component are polymerized to have a repeating unit derived therefrom.

The dicarboxylic acid component is terephthalic acid (TPA), isophthalic acid (IPA), naphthalene dicarboxylic acid (NDC), cyclohexane dicarboxylic acid (CHDA), succinic acid, glutaric acid, orthophthalic acid, adipic acid, Azelaic acid, sebacic acid, decanedicarboxylic acid, 2,5-furandicarboxylic acid, 2,5-thiophenedicarboxylic acid, 2,7-naphthalenedicarboxylic acid, 4,4'-bibenzoic acid and Derivatives thereof, or combinations thereof.

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

The diol component may include linear or branched aliphatic diols, alicyclic diols, aromatic diols, and the like.

For example, the linear or branched aliphatic diol is ethylene glycol (EG), diethylene glycol (DEG), neopentyl glycol, 1,3-propanediol, 1,2-octanediol, 1,3-octanediol , 2,3-butanediol, 1,3-butanediol, 1,4-butanediol, 1,5-pentanediol, 2-butyl-2-ethyl-1,3-propanediol, 2,2-diethyl-1, 5-pentanediol, 2,4-diethyl-1,5-pentanediol, 3-methyl-1,5-pentanediol, 1,1-dimethyl-1,5-pentanediol, 1,6-hexanediol, 2-ethyl-3-methyl-1,5-hexanediol, 2-ethyl-3-ethyl-1,5-hexanediol, 1,7-heptanediol, 2-ethyl-3methyl-1,5-heptanediol , 2-ethyl-3-ethyl-1,6-heptanediol, 1,8-octanediol, 1,9-nonanediol, 1,10-decanediol, and other derivatives or any combination thereof, It is not limited thereto.

In addition, the alicyclic diol may include cyclohexanedimethanol (CHDM), isosorbide, 2,2,4,4-tetramethyl-1,3-cyclobutanediol (CBDO), and the like, It is not limited thereto.

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

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

When the diol component is calendered with a polyester resin containing an alicyclic diol or an aromatic diol to prepare a film or sheet, it may be strongly bonded to the chemical structure, thereby improving impact strength and heat resistance.

As an example, the diol component is 10 to 90 mol%, 20 to 90 mol%, 20 to 85 mol%, 23 to 84 mol%, or 24 to 83 mol% of neopentyl glycol based on the total mole of the diol component, or It may include cyclohexanedimethanol.

In addition, the polyester resin is a dicarboxylic acid component and a diol component polymerized, the dicarboxylic acid component contains 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 includes (i) at least one of neopentyl glycol and cyclohexanedimethanol, and (ii) ethylene glycol. have.

The polyester resin composition according to the embodiment may further include components such as a polymerization catalyst, a stabilizer, and a colorant in addition to the polyester resin and a lubricant.

These polymerization catalysts, stabilizers, and colorants may be added to the product of the esterification reaction or the transesterification reaction prior to the initiation of the polymerization reaction, and may be added to the mixed slurry containing the dicarboxylic acid and the diol compound before the esterification reaction. It may be, and may be added during the esterification 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. Antimony trioxide, antimony acetate, antimony glycolate, etc. can be used as the antimony compound, and as the titanium compound, tetraethyl titanate, tetrapropyl titanate, tetrabutyl titanate, titanium dioxide, titanium dioxide /Silicone dioxide copolymer, etc. can be used, and germanium dioxide, germanium acetate, germanium glycolate, etc. can be used as the germanium-based compound.

As the stabilizer, a phosphorus compound such as phosphoric acid, trimethyl phosphate, or triethyl phosphate may be used, and the added amount may be 10 to 100 ppm based on the weight of the final polymer based on the mass of the phosphorus (P) element. If the amount of the stabilizer is less than 10 ppm, the stabilization effect may be insignificant and yellowing of the final polymer may occur. If the amount of the stabilizer exceeds 100 ppm, the activity of the polymerization catalyst may be inhibited, which may be disadvantageous in obtaining a polymer with high polymerization degree.

The coloring agent is added to improve the color of the polymer, and cobalt acetate, cobalt propionate metal salt coloring agent and a coloring agent as a dye component may be used, and the added amount 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 intrinsic viscosity (IV) of the polyester resin is 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/g, 0.64 It may be ~1.2 dl/g or 0.66 ~ 0.85 dl/g, but is not limited thereto.

When the intrinsic viscosity of the polyester resin is within the above range, the calendering processability is excellent, the kinematic viscosity retention rate during the calendering process is excellent, and the thickness uniformity of the sheet and film is excellent.

Method for producing polyester resin composition

The method for preparing the polyester resin composition includes the steps of: (1a) mixing a dicarboxylic acid component and a diol component to perform an esterification reaction; (1b) 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 to mix the diol component in an excessive amount in a ratio 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 blended in the above ratio, it is advantageous that the esterification reaction proceeds stably to form a sufficient ester oligomer.

On the other hand, adding an acrylic compound as a raw material for the polyester resin is not preferable because it can generate a non-melting gel.

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

The polycondensation step is performed in the presence of a polycondensation catalyst, a stabilizer, a colorant, a dispersant, an anti-blocking agent, an anti-static agent, an antistatic agent, an antioxidant, a heat stabilizer, a sunscreen agent, a photoinitiator, or any combination thereof, which are well known to those skilled in the art. It may be, and this may be included within a range that does not impair the effect of the resin composition.

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

The polycondensation catalyst may include an alkali metal, alkaline earth metal, antimony, titanium, manganese, cobalt, cerium, germanium, or any combination thereof, but is not limited thereto. 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 side reactions, and increase transparency.

As another example, the polycondensation step may be performed in the presence of a stabilizer.

The stabilizer may include a phosphorus stabilizer. The phosphorus stabilizer may include phosphoric acid, trimethylphosphate, triethylphosphate, triphenylphosphate, triethylphosphonoacetate, hindered phenol, or any combination thereof, but is not limited thereto. 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 performed in the presence of a vehicle.

The vehicle may include an organic vehicle, an inorganic vehicle, a dye, or a combination thereof, but is not limited thereto. Specifically, the vehicle may be cobalt acetate, cobalt propionate, 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 a lubricant are mixed to prepare a polyester resin composition.

At this time, the type and content of the lubricant to be added are as exemplified above.

Method for producing polyester film

A method of manufacturing a polyester film according to one embodiment,

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

(2) kneading the composition to form a gel (gelation); And

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

It will be described in detail for each step below.

In the above step (1), a composition is prepared by adding a lubricant to the polyester resin.

The polyester resin used at this time is one in which a dicarboxylic acid component and a diol component are polymerized as illustrated above.

Specifically, the dicarboxylic acid component includes terephthalic acid, isophthalic acid, naphthalene dicarboxylic acid, cyclohexanedicarboxylic acid, or a combination thereof, and the diol component is ethylene glycol, diethylene glycol, neopentyl glycol, cyclo Hexanedimethanol, or a combination thereof. In addition, at this time, the diol component may include at least one of neopentyl glycol and cyclohexanedimethanol in an amount of 30 to 90 mol% in total.

In addition, the lubricant may be added in an amount of 0.1 parts by weight or more to less than 10 parts by weight based on 100 parts by weight of the polyester resin.

As exemplified above, the lubricant has a weight reduction ratio of 1 to 20% compared to the initial period when maintained at 150°C for 100 minutes, and has a weight reduction ratio of 20 to 65% compared to the initial stage when maintained at 200°C for 100 minutes.

In addition, the lubricant may have a weight reduction rate of 30 to 70% compared to the initial period when the temperature is raised from 30°C to 350°C at a rate of 20°C/min.

In addition, the lubricant may have a weight reduction rate of 30 to 70% compared to the initial period when the temperature is raised from 350°C to 500°C at a rate of 20°C/min.

According to the embodiment, the lubricant is not particularly limited to its type as long as it satisfies the above thermal properties.

For example, the lubricant is 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. , More preferably, two or more types may be included, but the present invention is not limited thereto.

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

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

In addition, when the first lubricant is maintained at 150°C for 100 minutes, the weight reduction rate is 1 to 12% compared to the initial period, and when the second lubricant is maintained at 150°C for 100 minutes, the weight reduction rate is 10 to 25% compared to the initial stage. Can have.

In order to mix the polyester resin and additives, a high-speed mixer (eg, Henshell Mixer) may be used. For example, the polyester resin composition may be pelletized, the pelletized polyester resin may be added to 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 to form a gel.

The step of kneading and gelling the composition may include (2a) gelling using a planetary extruder or a Banbury intensive mixer; (2b) a step of homogenizing using a mixing roll; And (2c) may include at least one step selected from the step of homogenizing using a warming roll.

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

The temperature conditions in the process may be in the range of 180 to 230°C in the case of the (2a) process, 90 to 130°C in the case of the (2b) process, and 90 to 130°C in the case of the (2c) process. It is not limited.

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

The calendering step may be performed at a speed of 10 to 120 m/min in a temperature range of 145 to 210°C by using a plurality of calendering rolls, but is not limited thereto.

In addition, the calendering process may further include peeling the film from the calender roll using take off rolls and adjusting the thickness and smoothness of the film. The peeling and thickness and smoothness control of the film may be performed at a speed of 30 to 120 m/min in a temperature range of 120 to 170°C, but is not limited thereto.

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

For example, the surface treatment may be performed by a method such as embossing.

The embossing process refers to a process that shows a concave shape on the surface of the film by heat and pressure.

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

By passing through the surface treatment step, it is possible to improve the winding property and realize matte.

Then, the calendered film is cooled.

If the above embossing process is performed, peeling the film from the embossing unit using an annealing roll is performed first.

Such peeling may be performed at a rate of 40 to 130 m/min at a temperature of 5 to 80°C, but is not limited thereto.

The cooling of the calendered film may be performed at a speed of 30 to 120 m/min in a temperature range of -5°C to 50°C using a cooling roll.

Subsequently, the width of the manufactured film may be cut using a side trimming device, and the thickness of the manufactured film may be measured using a thickness gauge.

Thereafter, the cooled film may be wound. For example, the cooled film may be wound at a speed of 55 to 95 m/min using a winder, but 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 B to HB.

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

In addition, 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 this It is not limited.

In addition, 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, and that the haze of the film satisfies the above range means that the optical properties of the film are less deteriorated even when additional lamination of a printed layer or the like occurs, and thus product utilization is excellent.

The above contents will be described in more detail by the following examples. However, the following examples are only for illustrating the present invention, and the scope of the examples is not limited to these.

Examples 1 to 7 and Comparative Examples 1 to 5

In order to prepare a 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 pressure inside the reactor was increased to 2.0 kg/cm 2 using nitrogen gas, and the reaction was carried out while raising the temperature of the reactor to 265°C. At this time, the reaction product was transferred to a polycondensation reactor equipped with a stirrer, a cooling condenser, and a vacuum system after the esterification reaction was carried out while flowing the generated water to the outside.

To the obtained esterification reaction product, antimony triglycolate as a metal polycondensation catalyst was added to be 300 ppm based on the amount of antimony element, and triethyl phosphate (TEP) as a phosphorus stabilizer was added so as to be 500 ppm based on the amount of phosphorus. I did. Thereafter, a low vacuum reaction was performed for 40 minutes while raising the temperature and pressure inside 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, and the reaction proceeded to the maximum power value under high vacuum.

The polyester resin obtained in the polycondensation reaction was discharged and cut into chips. A composition was prepared by blending a lubricant in the polyester resin. The composition was extruded at 200°C on average, kneaded to gel, and calendered to prepare a film having a thickness of 0.2 mm.

In the above production process, terephthalic acid (TPA) and/or isophthalic acid (IPA) were used as the dicarboxylic acid component, and ethylene glycol (EG), neopentyl glycol (NPG) and/or cyclohexanedimethanol (CHDM) were used as the diol component. ) Was used, and two or more lubricants selected from stearic acid, palmitic acid, montan wax, and oxyol were used in combination as a lubricant.

In addition, the types and contents of the dicarboxylic acid component, diol component, and lubricant (mixing ratio in the final composition) are as shown in Table 1 below.

Test example

Each of the polyester resins, polyester resin compositions and polyester films prepared in 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 100° C. ortho-chlorophenol, the dropping time of the sample was measured with an Ostwald viscometer in a 35° C. thermostat, and the intrinsic viscosity (IV) was measured.

(2) process evaluation

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

-Sheet manufacturability: It was evaluated whether the sheet was well formed by the calendering process.

O: excellent sheet formation, △: normal sheet formation, X: poor sheet formation

-Releasability: It was evaluated whether the sheet was easily released without sticking to the processing roll during the process.

O: excellent releasability, △: moderate releasability, X: poor releasability

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

O: many bubbles occur, △: slightly normal bubbles, X: no bubbles

(3) lubricant thermal properties

For the lubricant, the weight reduction rate compared to the initial stage was measured at 150° C. and 200° C. by an isothermal TGA method (100 minutes delay), and the results are shown in Table 1.

In addition, for the lubricant, the weight reduction rate compared to the initial stage was measured in the range of 30 to 350°C in a temperature-raising TGA method (20°C/min) and shown in Table 1.

As shown in Table 1, in the case of Examples 1 to 7 using lubricants having thermal properties (weight reduction rate by temperature) according to the examples, it was evaluated excellently in terms of sheet production, releasability, and surface foam. On the other hand, in the case of Comparative Examples 2 to 5 using a lubricant that does not belong to the range of thermal properties of the Example, the process evaluation result was not good, and in the case of Comparative Example 1, the composition of the polyester resin was not satisfied, and thus the sheet could not be manufactured.

Claims (11)

A polyester resin in which a dicarboxylic acid component and a diol component are polymerized; And
A composition comprising 0.1 parts by weight or more to less than 10 parts by weight of a lubricant based on 100 parts by weight of the polyester resin,
The diol component contains at least one of neopentyl glycol and cyclohexanedimethanol in a total amount of 30 to 90 mol%,
The lubricant
When holding at 150°C for 100 minutes, it has a weight reduction ratio of 2 to 15% compared to the initial period,
A polyester resin composition for calendering having a weight reduction ratio of 25 to 65% compared to the initial period when maintained at 200° C. for 100 minutes.
delete The method of claim 1,
The composition comprises 0.1 to 5 parts by weight of the lubricant based on 100 parts by weight of the polyester resin, a polyester resin composition for calendering.
The method of claim 1,
The lubricant comprises a combination of a first lubricant and a second lubricant,
The weight ratio of the first lubricant and the second lubricant is in the range of 1:2 to 2:1, a polyester resin composition for calendering.
The method of claim 4,
When the first lubricant is maintained at 150° C. for 100 minutes, it has a weight reduction ratio of 1 to 12% compared to the initial period,
When the second lubricant is maintained at 150° C. for 100 minutes, the polyester resin composition for calendering has a weight reduction ratio of 10 to 25% compared to the initial period.
The method of claim 5,
When the first lubricant is maintained at 200° C. for 100 minutes, it has a weight reduction ratio of 20 to 45% compared to the initial period,
When the second lubricant is maintained at 200° C. for 100 minutes, the polyester resin composition for calendering has a weight reduction ratio of 40 to 80% compared to the initial period.
The method of claim 1,
The dicarboxylic acid component includes terephthalic acid, isophthalic acid, naphthalene dicarboxylic acid, cyclohexanedicarboxylic acid, or a combination thereof,
The diol component comprises ethylene glycol, diethylene glycol, neopentyl glycol, cyclohexane dimethanol, or a combination thereof, a polyester resin composition for calendaring.
delete The method of claim 1,
The polyester resin composition for calendering, wherein the polyester resin has an intrinsic viscosity (IV) of 0.6 to 1.0 dl/g.
The method of claim 1,
The lubricant comprises 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, Polyester resin composition for calendering.
(1) preparing a polyester resin composition by adding a lubricant to the polyester resin;
(2) kneading the composition to form a gel (gelation); And
(3) Calendering the gelled composition to form a film; as a method for producing a polyester film comprising,
In the polyester resin, a dicarboxylic acid component and a diol component are polymerized,
The amount of the lubricant added is 0.1 parts by weight or more to less than 10 parts by weight based on 100 parts by weight of the polyester resin,
The diol component contains at least one of neopentyl glycol and cyclohexanedimethanol in a total amount of 30 to 90 mol%,
The lubricant
When holding at 150℃ for 100 minutes, it has a weight reduction rate of 2 to 15% compared to the initial stage,
A method for producing a polyester film having a weight reduction ratio of 25 to 65% compared to the initial when maintained at 200° C. for 100 minutes.