KR101974605B1 - Polyester resin composition for calendering and preparation method of polyester film - Google Patents

Abstract

Since a polyester resin composition for calendaring according to an embodiment contains a lubricant with controlled thermal properties, it is possible to improve calendering processability and to suppress deterioration of the physical properties of a final film due to residual components. In addition, a polyester film manufactured by using the polyester resin composition for calendaring is eco-friendly and has excellent heat resistance and surface strength, thereby being able to be used as various eco-friendly materials such as a deco sheet and the like.

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a polyester resin composition for calendering and a method for producing the same. BACKGROUND ART < RTI ID = 0.0 >

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-cyclohexanedimethanol is further introduced, and the additive for preventing the polyester resin from adhering to the metal roll and improving the high temperature flowability Is known.

However, such an additive component exhibits an effect of improving the workability during the calendering process, but there is a problem in that the properties of the final film or sheet are lowered after the completion of the calendering process.

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 1 to 10 parts by weight based on 100 parts by weight of the polyester resin, wherein the lubricant comprises a first lubricant and a second lubricant, and the first lubricant is maintained at 150 DEG C for 100 minutes A weight reduction ratio of 1 to 12% relative to the initial weight at the time of holding, and a weight reduction ratio of 10 to 25% at the initial stage of maintaining the second lubricant at 150 占 폚 for 100 minutes.

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 100 wt% Wherein the lubricant comprises a first lubricant and a second lubricant, wherein when the first lubricant is maintained at 150 占 폚 for 100 minutes, a weight reduction rate of 1 to 12% , And the second lubricant has a weight reduction ratio of 10 to 25% at an initial stage at 150 DEG C for 100 minutes.

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.

Fig. 1 shows the test results of the thermal characteristics (isothermal TGA) of the lubricant used in Example 1. Fig.
Fig. 2 shows the test results of the thermal characteristics (temperature elevation TGA) of the lubricant used in Example 1. Fig.

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 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, the lubricant must be uniformly influenced from the gelation to the final stage. For this purpose, it is necessary to control the release amount of the lubricant for each section according to the process temperature.

In other words, in the calendering process, by controlling the thermal properties of the lubricant depending on the temperature rather than the type and content of the lubricant, the lubricant can be remarkably useful.

In particular, when two or more kinds of lubricants are used in combination and their thermal properties are controlled, it may be more advantageous to satisfy both the flowability inside the resin and the releasability outside the resin.

The lubricant is composed of two or more lubricants.

That is, the lubricant includes a first lubricant and a second lubricant.

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

That is, 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% .

Also, when the first lubricant is maintained at 200 ° 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 ° C for 100 minutes, the weight loss rate is 40 to 80% Lt; / RTI >

The types of the first and second lubricants are not particularly limited as long as the above respective thermal characteristics are satisfied.

Specifically, in the case of the first lubricant, if the lubricant satisfying the weight reduction ratio of 1 to 12% in the isothermal TGA analysis at 150 ° C. and 100 minutes can be selected regardless of its chemical structure and kind. Also, in the case of the first lubricant, it may be considered in selecting the lubricant that the weight reduction ratio in the range of 20 to 45% at 200 ° C and 100 minutes in the isothermal TGA analysis.

In the case of the second lubricant, if the lubricant satisfies a weight reduction ratio of 10 to 25% at 150 ° C and 100 minutes in isothermal TGA analysis, the lubricant can be selected regardless of its chemical structure and type. Also, in the case of the first lubricant, the weight reduction rate of 40 to 80% at 200 ° C and 100 minutes in the isothermal TGA analysis can be considered in selecting lubricants.

In addition, the first lubricant may be a combination of two or more lubricants if the above-mentioned thermal characteristics are satisfied. Likewise, the second lubricant may be a combination of two or more lubricants if the foregoing thermal characteristics are satisfied.

For example, the first lubricant may have (i) a weight reduction rate of 1 to 8% at the initial stage of holding at 150 DEG C for 100 minutes, and a weight reduction rate of 20 to 35% And (ii) a lubricant mixture having a weight reduction rate of 4 to 12% at an initial stage of holding at 150 DEG C for 100 minutes and a weight loss rate of 25 to 45% at an initial stage of maintaining at 200 DEG C for 100 minutes .

Alternatively, the first lubricant may contain (i) a lubricant having a weight reduction rate of 1 to 6% at an initial stage of holding at 150 DEG C for 100 minutes and a weight loss rate of 20 to 30% , And (ii) a mixture of lubricants having a weight loss rate of 6 to 12% at the initial stage of holding at 150 DEG C for 100 minutes and a weight loss rate of 30 to 45% at the initial stage of holding at 200 DEG C for 100 minutes .

Also, the second lubricant preferably has (i) a weight loss rate of 10 to 20% at an initial stage of holding at 150 DEG C for 100 minutes, and a lubricant having a weight loss rate of 40 to 70% , And (ii) a mixture of lubricants having a weight loss rate of 15 to 25% at the initial stage of maintaining at 150 DEG C for 100 minutes and a weight loss rate of 50 to 80% at the initial stage of maintaining at 200 DEG C for 100 minutes .

Also, the second lubricant preferably has (i) a weight loss rate of 10 to 17% at an initial stage of holding at 150 DEG C for 100 minutes, and a lubricant having a weight loss rate of 40 to 60% , And (ii) a mixture of lubricants having a weight loss rate of 17 to 25% at the initial stage at 150 DEG C for 100 minutes and a weight loss rate of 60 to 80% at the initial stage of maintaining at 200 DEG C for 100 minutes .

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 releasability to the metal roll, and the second lubricant can improve the flowability of the resin composition in the calendering process.

The content of the lubricant is not less than 1 part 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 1 to 5 parts by weight, 1 to 4 parts by weight, 1 to 3 parts by weight, 1 to 2 parts by weight, 2 to 3 parts by weight, 2 to 4 parts by weight, By weight, 3 to 5 parts by weight, or 5 to 10 parts by weight, but 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.

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.

In addition to the first and second lubricants, the lubricant may further include additional lubricants having different thermal properties (i.e., third lubricant, fourth lubricant, etc.).

On the other hand, when two or more kinds of lubricants are used in combination, not only the lubricant itself but also other lubricants tend to elute together when one kind of lubricant used is eluted. Therefore, even when two or more kinds of lubricants are used in combination, it is preferable to take into account the elution amount of the whole lubricant depending on the process temperature range.

According to this embodiment, the lubricant (i.e., the lubricant containing the first lubricant and the second lubricant) has a specific range of weight reduction rate depending on the temperature condition.

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 the weight reduction rate is within the above-mentioned 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. When the weight reduction rate is within the above-mentioned range, carbonization on the working roll surface does not occur and it is advantageous from the viewpoint of reduction in frictional force between the sheet and the roll and releasability.

As another example, the lubricant may have a weight reduction rate of 30 to 70%, 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 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 combinations 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.

As an example, the diol component may comprise neopentyl glycol or cyclohexanedimethanol in a total amount of 10-90 mol%, 20-90 mol%, 30-90 mol%, 30-80 mol%, 30-70 mol% (Based on the total mole of diol component). Within the above-mentioned preferable range, the processability due to crystallization can be improved, and it is more advantageous in view of the inherent viscosity, hue and mechanical properties of the resin. On the other hand, if it exceeds 90 mol%, it is difficult to raise the intrinsic viscosity of the resin to a certain level or more, so that the mechanical properties may become weak.

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 comprises 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 phosphorus (P), 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 impaired and it may be disadvantageous to obtain 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 may be 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 UV blocking agent, a photoinitiator, And may be included within a range that does not impair the effects 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 at 1 to 500 ppm, or 1 to 200 pp, 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 is added in an amount of 1 part by weight to less than 10 parts by weight based on 100 parts by weight of the polyester resin.

As exemplified above, the lubricant comprises a first lubricant and a second lubricant,

When the first lubricant is maintained at 150 DEG C for 100 minutes, the weight of the first lubricant is 1 to 12%

When the second lubricant is maintained at 150 DEG C for 100 minutes, the weight loss rate of the second lubricant is 10 to 25%.

Also, the first lubricant had a weight reduction rate of 20 to 45% at the initial stage of maintaining at 200 DEG C for 100 minutes,

The second lubricant may have a weight reduction rate of 40 to 80% when maintained at 200 DEG C for 100 minutes.

In addition, the lubricant (i.e., the lubricant containing the first lubricant and the second lubricant) had a weight reduction rate of 1 to 20% at an initial stage of maintaining at 150 DEG C for 100 minutes, And can have a weight reduction rate of 20 to 65%.

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. In addition, the lubricant may have a weight reduction rate of 30 to 70% at an initial temperature rise rate of 300 ° C to 500 ° C at a rate of 20 ° C / minute.

In addition, the composition may include the lubricant in an amount of 1 to 5 parts by weight based on 100 parts by weight of the polyester resin, and the first lubricant and the second lubricant in a weight ratio ranging from 1: 2 to 2: 1 .

According to the embodiment, the types of the first and second lubricants are not particularly limited as long as the respective thermal characteristics are satisfied.

For example, the lubricant (such as the first lubricant and the second 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, Acrylic copolymers, but are not limited thereto.

Specifically, the lubricant may be 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.

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 calendered 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 ) Were used.

As a lubricant, two or more of the following five lubricants were used in combination as shown in Table 1 below.

- A-1: Isothermal TGA (150 캜, 100 min) weight reduction rate 3.2%, isothermal TGA (200 캜, 100 min) weight reduction rate 26.2%

- A-2: Isothermal TGA (150 캜, 100 min) weight reduction rate 7.2%, isothermal TGA (200 캜, 100 min) weight reduction rate 34.5%

- B-1: Isothermal TGA (150 ℃, 100min) Weight reduction rate 14.7%, Isothermal TGA (200 ℃, 100min) Weight reduction rate 56.7%

- B-2: Isothermal TGA (150 ° C, 100 min) Weight reduction rate 19.2%, Isothermal TGA (200 ° C, 100 min) Weight reduction rate 68.4%

- C-1: Isothermal TGA (150 캜, 100 min) Weight reduction rate 25.3%, Isothermal TGA (200 캜, 100 min) Weight reduction rate 88.7%

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

- Unsorbed gel: After the process, it was evaluated whether the untransferred gel remained in the sheet.

  O: many unmelted gels were observed,?: Slightly unmelted gels were observed, and X: unmelted gels were not observed.

(3) Lubricant thermal properties

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

In addition, the weight loss rate of the lubricant was measured at a temperature elevation TGA (20 캜 / min) in the range of 30 to 300 캜, and is shown in Table 1.

The isothermal TGA and temperature TGA test results of the lubricant used in Example 1 are shown in FIGS. 1 and 2, respectively.

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, the surface bubbles and the migration surface were excellent. On the other hand, in Comparative Examples 4 and 5 using a lubricant not belonging to the thermal characteristic range of the Examples, the process evaluation results were not good. In addition, in Comparative Examples 2 and 3, the amount of the lubricant used was too small or excessive, and the result of the evaluation of the process was not good. In Comparative Example 1, the composition of the polyester resin was not satisfied and the sheet could not be produced.

Claims (15)

A polyester resin in which a dicarboxylic acid component and a diol component are polymerized; And
A composition comprising from 1 part by weight to less than 10 parts by weight of a lubricant based on 100 parts by weight of the polyester resin,
Wherein the lubricant comprises a first lubricant and a second lubricant, the first lubricant has a weight reduction ratio of 1 to 12% at an initial stage of maintaining at 150 DEG C for 100 minutes, and the second lubricant is maintained at 150 DEG C for 100 minutes The weight reduction rate of 10 ~ 25%
Wherein the lubricant has a weight reduction ratio of 30 to 70% at an initial temperature rise from 30 占 폚 to 350 占 폚 at a rate of 20 占 폚 / min.
The method according to claim 1,
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,
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.
delete The method according to claim 1,
Wherein the composition contains 1 to 5 parts by weight of the lubricant based on 100 parts by weight of the polyester resin,
Wherein the first lubricant and the second lubricant are contained in a weight ratio ranging from 1: 2 to 2: 1.
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.
The method according to claim 1,
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.
(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,
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 1 part by weight and less than 10 parts by weight based on 100 parts by weight of the polyester resin,
Wherein the lubricant comprises a first lubricant and a second lubricant, the first lubricant has a weight reduction ratio of 1 to 12% at an initial stage of maintaining at 150 DEG C for 100 minutes, and the second lubricant is maintained at 150 DEG C for 100 minutes The weight reduction rate of 10 ~ 25%
Wherein the lubricant has a weight loss ratio of 30 to 70% at an initial temperature rise rate of 30 ° C to 350 ° C at a rate of 20 ° C / minute.
11. The method of claim 10,
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.
12. The method of claim 11,
The lubricant
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.
11. The method of claim 10,
Wherein the composition contains 1 to 5 parts by weight of the lubricant based on 100 parts by weight of the polyester resin,
Wherein the first lubricant and the second lubricant are contained in a weight ratio ranging from 1: 2 to 2: 1.
14. The method of claim 13,
(I) a lubricant having a weight reduction rate of 1 to 6% at an initial stage of maintaining at 150 DEG C for 100 minutes and a weight reduction rate of 20 to 30% at an initial stage of maintaining at 200 DEG C for 100 minutes, and (ii) a lubricant mixture having a weight loss rate of 6 to 12% at an initial stage of holding at 150 DEG C for 100 minutes and a weight loss rate of 30 to 45% at an initial stage of holding at 200 DEG C for 100 minutes,
(I) a lubricant having a weight reduction ratio of 10 to 17% at an initial stage at 150 DEG C for 100 minutes and a weight reduction rate of 40 to 60% at an initial stage of maintaining at 200 DEG C for 100 minutes, and (ii) a polyester film which is a mixture of lubricants having a weight reduction ratio of 17 to 25% at an initial stage of maintaining at 150 DEG C for 100 minutes and a weight reduction rate of 60 to 80% at an initial stage of maintaining at 200 DEG C for 100 minutes ≪ / RTI >
11. The method of claim 10,
Wherein the dicarboxylic acid component comprises terephthalic acid, isophthalic acid, naphthalene dicarboxylic acid, cyclohexanedicarboxylic acid, or combinations thereof;
Wherein the diol component comprises ethylene glycol, diethylene glycol, neopentyl glycol, cyclohexanedimethanol, or a combination thereof;
Wherein the diol component comprises at least one of neopentyl glycol and cyclohexanedimethanol in a total amount of 30 to 90 mol%.

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