KR101673550B1 - Heat shrinkable polyester film with excellent slip property - Google Patents

Abstract

The present invention relates to a heat-shrinkable polyester film having improved slipperiness, and more particularly to a heat-shrinkable polyester film having excellent basic properties such as heat resistance, printing properties, shrinkage uniformity and stretchability, Shrinkable polyester film having improved slipability capable of simultaneously achieving anti-blocking properties. For this purpose, in the present invention, slip coating including a copolyester resin and a wax-based slipping agent for anti-blocking property is applied to one surface or both surfaces of a heat-shrinkable polyester film to control the slip property of the film, A heat-shrinkable polyester film with improved slip property which improves workability at the time of casting and prevents fusion prevention phenomenon.

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention [0001] The present invention relates to a heat shrinkable polyester film having improved slip properties,

The present invention relates to a heat-shrinkable polyester film having improved slipperiness, and more particularly to a heat-shrinkable polyester film having excellent basic properties such as heat resistance, printing properties, shrinkage uniformity and stretchability, Shrinkable polyester film having improved slipability capable of simultaneously achieving anti-blocking properties.

Generally, polyvinyl chloride, polystyrene, polypropylene, polyethylene or the like is used as the heat shrinkable film. However, polyvinyl chloride films have very poor environmental compatibility due to problems such as chlorine gas and dioxin emission during incineration. The polystyrene-based film can be evaluated in terms of good finishing appearance after shrinkage. However, since the solvent resistance is poor, it is necessary to use an ink having a specific composition at the time of printing. The polypropylene-based film has poor shrinkability at low temperatures, and wrinkles and unevenness tend to occur at the shrinkage portion. In addition, all of the above films are insufficient in heat resistance, and are easily melted or ruptured during the boiling treatment or the retort treatment, making it difficult to maintain the film state.

In recent years, studies on polyester-based heat-shrinkable films have been actively conducted to solve these problems, and they have been attracting attention as shrinkable labels replacing polyvinyl chloride films and polystyrene films. In order to increase the usage of PET containers The usage is also gradually increasing. However, since the heat-shrinkable polyester film can achieve uniform shrinkage due to low-temperature shrinkage and low shrinkage rate, good shrink appearance can be highly evaluated, but since the solvent resistance is poor, it is necessary to use a special composition ink But also has a problem in that it is difficult to store because of its large natural shrinkage ratio. Further, in the regeneration of the PET bottle, the polyester shrink film of the same material is disadvantageous in that it is difficult to separate the gravity difference and the recyclability is deteriorated. In addition, the heat-shrinkable polyester film may cause dust or the like in the air to adhere to the film due to static electricity in the labeling process at the time of post-processing, or may cause a cutting defect due to static electricity in a high-speed cutting process, There is a problem that the labels stick together.

In addition, if the slip property of the film is poor, the workability at the time of high-speed labeling may be deteriorated to cause defective products, and if the slip property, the solvent adhesion, and the blocking property are not simultaneously achieved, optimization of the user process is difficult.

In order to solve such a problem, Korean Patent Laid-Open Publication No. 2002-0073305 discloses a method for forming a coating layer containing a quaternary ammonium sulfate derivative and a polysiloxane resin on at least one surface of a film to improve antistatic property, slip property and blocking resistance . However, when such a silicone slip agent is used as in the above patent, the slip property is improved, but the solvent adhesion force is reduced to an unusable level.

Accordingly, the present inventors have made efforts to solve the above-mentioned problems. As a result, the present inventors have found that, by subjecting a heat-shrinkable polyester film itself to slip coating including a copolyester resin for blocking resistance and a wax-based slipping agent, , The workability at the time of high-speed labeling in the user process is improved, and at the same time, the fusion prevention phenomenon is improved to complete the present invention.

Korean Patent Publication No. 2002-0073305

SUMMARY OF THE INVENTION The present invention has been made in order to solve the above-mentioned problems, and it is an object of the present invention to provide a heat-shrinkable polyester film with improved slipperiness and simultaneously improved anti- .

Specifically, a slip coating layer containing a copolyester resin and a wax-based slipping agent is formed on at least one surface of a heat-shrinkable polyester film to control the slip property of the film to improve workability in high-speed labeling in a user process, And to provide a heat-shrinkable polyester film with improved slipperiness which has an excellent solvent adhesion.

These and other objects and advantages of the present invention will become more apparent from the following description of a preferred embodiment thereof.

This object is achieved by a heat-shrinkable polyester film with improved slip properties, characterized in that it comprises a coating layer applied on at least one side of a polyester base film with a slip coating composition comprising an antistatic composition and a wax-based slipping agent do.

Here, the antistatic composition is characterized by comprising copolymerized polyester, methyl methacrylate copolymer and alkyl phosphate.

Preferably, the slip coating composition comprises an antistatic composition comprising 5 to 20 parts by weight of the methyl methacrylate copolymer and 20 to 60 parts by weight of the alkyl phosphate per 100 parts by weight of the copolymerized polyester, and the antistatic composition 100 And 3 to 20 parts by weight of the wax-based slip relative to the weight.

Preferably, the wax-based slipping agent is at least one of a polyethylene-based or polypropylene-based wax.

Preferably, the coating layer has a static friction coefficient of 0.35 or less and a dynamic friction coefficient of 0.25 or less.

More preferably, the coating layer has a static friction coefficient of 0.16 to 0.35 and a dynamic friction coefficient of 0.20 to 0.25.

Preferably, the surface resistivity of the coating layer is not more than 1 × ^{10 10} Ω / sq.

Preferably, the dicarboxylic acid component of the polyester base film is terephthalic acid or dimethyl terephthalate, and the diol component is a mixture of 60 to 90 mol% of ethylene glycol with neopentyl glycol, 1,4-cyclohexanedimethanol, diethylene glycol , Propanediol, and butanediol, and 10 to 40 mol% of at least one diol selected from the group consisting of propanediol and butanediol.

Preferably, the heat-shrinkable polyester film has a shrinkage ratio in the main shrinkage direction measured after immersing in hot water at 90 캜 for 10 seconds of 30% or more.

Preferably, the thickness of the coating layer is 0.5 to 5.0 mu m.

According to the present invention, it is possible to minimize the defect rate in the user process and improve the workability, thereby achieving cost reduction.

Further, it is possible to provide an antistatic layer on one side of the film to provide a slip-property-improving heat-shrinkable polyester film which is excellent in antistatic performance and post-processability and has improved slip property, excellent blocking resistance and solvent adhesion I have.

However, the effects of the present invention are not limited to the effects mentioned above, and other effects not mentioned can be clearly understood by those skilled in the art from the following description.

Hereinafter, the present invention will be described in detail with reference to examples of the present invention. It will be apparent to those skilled in the art that these embodiments are provided by way of illustration only for the purpose of more particularly illustrating the present invention and that the scope of the present invention is not limited by these embodiments .

Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs. In case of conflict, the present specification, including definitions, will control.

Although methods and materials similar or equivalent to those described herein can be used in the practice or testing of the present invention, suitable methods and materials are described herein.

Unless otherwise stated, all percentages, parts, and percentages are by weight. It will also be understood that when an amount, concentration, or other value or parameter is given in any one of a range, a preferred range, or a list of preferred upper limits and preferred lower limits, it is understood that any upper limit range, It should be understood that specifically all ranges formed from any pair of range limits or desirable values are to be understood. Where a range of numerical values is referred to in this specification, unless otherwise stated, the range is intended to include all the integers and fractions within the endpoint and its range. The scope of the present invention is not intended to be limited to the specific values that are mentioned when defining the scope.

When the term "about" is used to describe the endpoint of a value or range, it is to be understood that the present disclosure encompasses the particular value or endpoint mentioned.

As used herein, the terms "comprise," "include," "including," "including," "containing," " Having ", " having ", " having ", or any other variation thereof, are intended to cover an inclusion not exclusive. For example, a process, method, article, or apparatus that comprises a list of elements is not necessarily limited to such elements, but may include other elements not expressly listed or inherent to such process, method, article, or apparatus It is possible. Also, unless explicitly stated to the contrary, "or" does not mean " comprehensive " or " exclusive "

Where an applicant defines an invention or portion thereof in an open term such as "comprising ", it should be readily understood that the description should be interpreted as describing the invention using the term" consisting essentially & do.

In describing a given polymer, it is sometimes understood that the applicant refers to a polymer by the amount of monomers used to make the polymer or the monomers used to make the polymer. Such a description may not include the specific nomenclature used to describe the final polymer or may not include product-by-process terms, but any such reference to monomers and amounts is intended to encompass the use of the polymer Should be construed to mean that they include the amounts of these monomers (i.e., the copolymerized units of these monomers) or monomers, and the corresponding polymers and compositions thereof.

In describing and / or claiming the present invention, the term "copolymer" is used to refer to a polymer formed by copolymerization of two or more monomers. Such copolymers include binary copolymers, terpolymers, or higher order copolymers.

The heat-shrinkable polyester film having improved slip properties according to the present invention can be obtained by adjusting the slip property of the film by applying a slip coating containing at least one surface of a polyester base film and a copolyester resin and a polyethylene or polypropylene wax slip agent A heat-shrinkable polyester film with improved slipperiness which is excellent in anti-blocking property, solvent adhesion and workability at the time of high-speed labeling in a user process.

The polyester base film of the heat-shrinkable polyester film having improved slip properties according to the present invention can be produced by copolymerization of a dicarboxylic acid and a diol component and addition of silica particles, and the dicarboxylic acid is preferably dimethyl terephthalate, Terephthalic acid, isophthalic acid, 2,6-naphthalene dicarboxylic acid, sebacic acid, adipic acid, diphenyldicarboxylic acid, 5-tert-butylisophthalic acid, 2,2,6,6- 4,4'-dicarboxylic acid, 1,1,3-trimethyl-3-phenylindan-4,5-dicarboxylic acid, 5-sodium sulfoisophthalic acid, trimellitic acid, oxalic acid, malonic acid, , Dicarboxylic acid esters such as dicarboxylic acid, dicarboxylic acid, maleic acid, maleic acid, maleic acid, maleic acid, maleic acid, maleic acid, Wherein the first component of the bicarboxylic acid and the diol component comprise about 100 mole% 10 to 40 mol% of at least one compound selected from the group consisting of neopentyl glycol, 1,4-cyclohexanedimethanol, diethylene glycol, propanediol and butanediol is mixed with 60 to 90 mol% of tylene glycol, 10 to 40 mol% of neopentyl glycol is mixed with 60 to 90 mol% of ethylene glycol, and silica particles having an average particle diameter of 1 to 5 μm are contained in an amount of 0.01 to 1 wt% based on the weight of the polyester resin to prepare a copolymerized polyester resin can do. When the content of neopentyl glycol in the diol component is less than 10 mol%, the dimensional stability of the copolymer polyester is increased, and it is difficult to realize a sufficient heat shrinkage rate, and the shrinking speed and shrinking stress are too high, If the content of pentyl glycol is more than 40 mol%, crystallization of the produced chips is difficult, so that chips are welded to each other in a raw material drying process to prevent hydrolysis, thereby causing process troubles. In addition to silica particles, organic particles such as PE and PMMA, inorganic particles such as SiO ₂ and CaCO ₃ , or organic hybrid particles may be used.

And a coating layer coated with a slip coating composition comprising an antistatic composition and a wax-based slipping agent on one or both sides of the substrate as described above.

The antistatic composition may comprise a copolymerizable polyester, a methyl methacrylate copolymer and an alkyl phosphate, wherein 5 to 20 parts by weight of a methyl methacrylate copolymer and 20 to 60 parts by weight of an alkyl phosphate, based on 100 parts by weight of the copolymerized polyester, Antistatic compositions are preferred.

It is preferable that the antistatic composition further comprises 3 to 20 parts by weight of a wax-based slipping agent based on 100 parts by weight of the antistatic composition. When the amount of the slipping agent is less than 3 parts by weight, it is difficult to exhibit sufficient slipping property. If the amount is more than 20 parts by weight, not only the adhesive strength of the solvent is insufficient, but also it is difficult to ensure the winding property of the film due to slipperiness.

The frictional coefficient of the surface of the coating layer is preferably not more than 0.35 and the coefficient of dynamic friction is not more than 0.25. When the coefficient of static friction is more than 0.35 and the coefficient of dynamic friction is more than 0.25 There is a disadvantage in that it may cause defects in a high-speed label shooting process because it does not have sufficient slip property. More preferably, the coefficient of static friction of the coating layer is 0.16 to 0.35 and the coefficient of dynamic friction is 0.20 to 0.25. When the coefficient of static friction of the coating layer is less than 0.16 and the coefficient of dynamic friction is less than 0.20, the winding property is poor and the adhesive strength of the solvent deteriorates.

Preferably, the thickness of the coating layer on one side or both sides of the heat-shrinkable polyester base film according to the present invention is preferably 30 to 70% in the thickness ratio with respect to the total thickness of the heat-shrinkable polyester film.

The heat shrinkable polyester film according to the present invention has a shrinkage in the main shrinkage direction measured after immersing in hot water at 90 캜 for 10 seconds is 30% or more, preferably 50% or more, and more preferably 70% or more. If the shrinkage ratio in the main shrinking direction is less than 30%, there is a problem that the shrinkage rate is insufficient for labeling a product having a bottle bending.

The heat shrinkage ratio in the main shrinkage direction measured after immersing in hot water at 90 DEG C for 10 seconds and the heat shrinkage difference in the main shrinkage direction measured after immersing in hot water at 80 DEG C for 10 seconds is 40% or less, preferably 30% or less . In the temperature range of 80 to 90 占 폚, which is the steam temperature of a commonly used steam tunnel, the heat shrinkage difference is set to 40% or less so that shrinkage fluctuation caused by temperature fluctuation of water vapor is suppressed when labeling the object, This is because defective finishing defects such as pear marks can be suppressed.

Next, a method of producing the slip-property-improving heat-shrinkable polyester film according to the present invention will be described.

The heat-shrinkable laminated film according to the present invention can be produced by a known method. The shape of the film may be either a plane shape or a tube shape, but a planar shape is preferable in view of productivity and printing on the inner surface. As a method for producing a planar film, for example, a resin is melt-extruded using a plurality of extruders, co-extruded from a T-die, and cooled and solidified by a roll to obtain a sheet. The film is stretched at a temperature not lower than the glass transition temperature by the tenter method without performing roll stretching in the longitudinal direction of the obtained sheet, and is heat-treated and cooled to obtain a film. The stretching temperature in the stretching step is preferably 60 to 100 占 폚, preferably 70 to 90 占 폚. If the stretching temperature is less than 60 캜, stretching occurs at a temperature lower than the glass transition temperature of the copolyester resin, so that breakage occurs and stretching is impossible. When the stretching temperature is 100 캜 or more, the elasticity of the material is lowered. Can not.

The stretching magnification is suitably in the uniaxial or biaxial stretching direction of 3.0 to 7.0 times, preferably 3.5 to 5.0 times in the main shrinkage direction depending on the properties of the resin composition to be used, the stretching means, the stretching temperature and the use of the product. When the stretching ratio is less than 3.0 times, it is difficult to realize a sufficient heat shrinkage. When the stretching ratio exceeds 7.0 times, the shrinking stress value becomes excessive, or the frequency of occurrence of fracture due to stretching beyond the yielding point is increased. Even in the case of uniaxial stretching in the transverse direction, it is also effective to give about 1.05 to 1.8 times of stretching in the longitudinal direction for the purpose of improving the mechanical properties in the longitudinal direction. The stretched film is subjected to a heat treatment or relaxation treatment at a temperature of 100 DEG C or less for the purpose of reducing the natural shrinkage ratio or improving the heat shrinkage property as required, and then rapidly cooled within a time period during which the molecular orientation is not relaxed, An ester film can be obtained.

Further, the film according to the present invention preferably has a thickness of 12 to 125 占 퐉, and there is no particular thickness limitation when the film is produced. The heat-shrinkable laminated film of the present invention is mainly processed into a sleeve (cylindrical) shape. In the case of printing on a rectangular or cylindrical container such as a PET bottle, first, one side of a wide-width film on which a roll is wound is printed, cut into a required width, and folded folded and center sealed to form a cylindrical shape. Examples of the center sealing method include an adhesive method using an organic solvent, a method using an adhesive, and a method using an impulse sealer. Among these methods, an adhesive method using an organic solvent is preferably used from the viewpoints of productivity and appearance.

The film according to the present invention is not particularly limited in its use, but it is also possible to form a printing layer, a vapor deposition layer, and other functional layers (antistatic function, running property improving function, UV cutoff function, etc.) It can be used for labeling and packaging. When used as a heat-shrinkable label, it can be adhered to a complicated shape, and a container equipped with an elegant label free from wrinkles and puckering due to uneven shrinkage can be obtained.

Hereinafter, the structure and effect of the present invention will be described in more detail with reference to examples and comparative examples. However, this embodiment is intended to explain the present invention more specifically, and the scope of the present invention is not limited to these embodiments.

[ Example ]

< Manufacturing example  1>

100 mol% of dimethyl terephthalate as a dicarboxylic acid component, 80 mol% of ethylene glycol as a diol component and 20 mol% of neopentyl glycol were charged into an autoclave equipped with a stirrer and a distillation tower, and then manganese acetate as a transesterification catalyst 0.07% by weight based on the amount of dimethyl terephthalate. 2 kg / cm &lt; 2 &gt;, and the reaction was allowed to proceed while raising the temperature to 250 DEG C while removing water as a by-product. After the esterification reaction was completed, 0.02 wt% of trimethyl phosphate as a heat stabilizer was added to the second reactor equipped with a vacuum system, and 0.04 wt% of antimony trioxide was added as a polymerization catalyst in 10 minutes. Thereafter, while the temperature was gradually raised to 285 DEG C, the pressure was reduced gradually to 1 torr or less over 50 minutes, and the copolymer was polymerized for 240 minutes while removing the excess diol component through a vacuum line to obtain a copolymer polyester having an intrinsic viscosity of 0.70 dl / g. The polymer obtained in Preparation Example 1 was melt-extruded at 250 占 폚 with 0.07 wt% of amorphous spherical silica particles having an average particle diameter of 3 占 퐉 and co-extruded from a T-die, followed by quenching by casting to obtain an unstretched sheet .

< Example  1>

The obtained unoriented sheet was subjected to corona discharge treatment on the surface of the film to be coated. On the corona-treated surface, 58 wt% of copolymerized polyester, 8 wt% of methyl methacrylate copolymer and 34 wt% of alkyl phosphate were mixed as a slip coating layer , And 5 parts by weight of a polypropylene wax as a slip agent to 100 parts by weight of an antistatic composition was added to the antistatic composition. The antistatic composition was applied to the antioxidant composition by Meyer bar coating method, Deg.] C, stretched 4.0 times in the transverse direction at 80 DEG C, and heat-treated at 60 DEG C to prepare a heat shrinkable polyester film having a thickness of 50 mu m.

< Comparative Example  1>

A heat-shrinkable polyester film was produced in the same manner as in Example 1, except that 30 parts by weight of polypropylene wax as a slip agent was added to 100 parts by weight of the antistatic composition.

< Comparative Example  2>

A heat-shrinkable polyester film was produced in the same manner as in Example 1, except that 1 part by weight of polypropylene wax as a slip agent was added to 100 parts by weight of the antistatic composition in Example 1.

< Comparative Example  3>

A heat-shrinkable polyester film was prepared in the same manner as in Example 1, except that 20 parts by weight of silicone-based slip agent was added to 100 parts by weight of the antistatic composition in Example 1.

< Comparative Example  4>

A heat-shrinkable polyester film was produced in the same manner as in Example 1, except that the slip agent was not added.

< Comparative Example  5>

A heat-shrinkable polyester film was produced in the same manner as in Example 1, except that the slip agent was not added in Example 1 and 0.05 wt% of silica particles having a size of 5 μm was added.

< Comparative Example  6>

A heat-shrinkable polyester film was prepared in the same manner as in Example 1, except that slip agent was not added and silica particles having a size of 5 탆 were added in an amount of 0.1 wt%.

The properties of the heat-shrinkable polyester films according to Example 1 and Comparative Examples 1 to 6 were measured through the following experimental examples, and the results are shown in Table 1 below.

[ Experimental Example ]

(One) Heat shrinkage

The film was cut into a square of 10 cm x 10 cm and immersed in hot water maintained at a temperature of 90 deg. C for 10 seconds in a no load state, and the length was measured. The heat shrinkage rate was determined according to the following formula.

Heat shrinkage percentage (%) = 100 X (length before shrinkage - length after shrinkage) / (length before shrinkage)

(2) Antistatic property

After standing for 8 hours under the condition of 25 占 폚 X 55 RH%, the antistatic property was evaluated with a surface resistance meter (ADVANTEST, manufactured by Advantec, Japan). The unit is Ω / sq.

(3) Slipperiness (Coefficient of friction)

The kinetic / static friction coefficient was measured according to ASTM D1894 under the conditions of 25 캜 and 60 RH. The length (mm) of the lower specimen was 250 X 130, the length (mm) of the upper specimen was 65 X 60, and the average of the remaining values except for the maximum and minimum values was measured five times at a rate of 150 mm / min.

 (4) Surface roughness

Surface roughness was measured using a three - dimensional surface roughness meter. Measurements were made on the basis of the coated surface. According to JIS B0601 standard, it was measured by SE-3H Model of KOSAKA.

(5) My blocking ability

The film-coated side was abutted against each other using a roller type laminator, peeled off at a temperature of 120 占 폚 under a pressure of 2 kg / cm2 at a rate of 5 mpm, and peeled to evaluate the anti-blocking property.

○: It is peeled cleanly without stickiness.

△: The sticking mark remains but peelable.

X: Fusing between films occurs, and peeling is impossible.

(6) Solvent adhesion

1,3-dioxolane solvent was applied to an area of 20 x 5 mm ² at a coating amount of 5 g / m ² using a brush, followed by sealing with two films. The sealing part was set in a universal tensile tester STM-50 and measured at a tensile speed of 20 mm / min by a 180-peel test.

(7) Hayes

The haze was measured using a haze meter according to JIS K7136.

(8) Printing characteristics

The nitrocellulose ink was applied to the surface of the film, and then a grid pattern was formed on the surface of the film at regular intervals using a razor blade. Subsequently, when a 3M 610M scotch tape was adhered to the coated surface of the film and then rub-off test was rapidly performed (rub-off test), the degree of transfer of the ink on the tape adhesion surface was evaluated and evaluated as follows.

○: Ink transfer rate to 3M tape 0%

DELTA: ink transfer rate to 3M tape less than 30%

Х: 30% or more ink transfer rate for 3M tape

(9) Adhesion

Five rounds of rubbing with a thumb were rubbed and evaluated visually.

◎ (No smear): No change after evaluation

○ (Slightly smear): It is fine but there is no problem in use

△ (Smear): As the oil is pushed, the coating layer becomes cloudy.

Х (Rub-off): The coating layer clumps off

division Example 1
Comparative Example 1 Comparative Example 2 Comparative Example 3 Comparative Example 4 Comparative Example 5 Comparative Example 6 Heat shrinkage
(%) 72 72 73 72 75 72 71 Surface roughness
(nm) 20 25 20 15 20 50 65 friction
Coefficient dynamic 0.32 0.19 0.58 0.30 0.62 0.50 0.43 silence 0.23 0.15 0.47 0.15 0.51 0.43 0.35 Surface resistance
(Ω / sq) 7X10 ⁸ 7X10 ⁸ 6X10 ⁸ 6X10 ⁸ 9X10 ⁸ 6X10 ⁸ 7X10 ⁸ My blocking ability ○ ○ △ ○ △ ○ ○ Solvent Adhesion (g) 800 250 730 105 350 650 720 Printing characteristics ○ ○ ○ △ ○ ○ ○ Adhesion ◎ ◎ ◎ X ◎ ◎ ◎

As can be seen from Table 1, it can be seen that Example 1 according to the present invention has excellent physical properties.

However, in Comparative Example 1, similar physical properties are exhibited as compared with Example 1, but the coefficient of friction is low due to too much wax amount, resulting in poor windability and poor solvent adhesion. On the other hand, in the case of Comparative Example 2 in which the wax was used in an excessively small amount, the friction coefficient could not be lowered and it was difficult to improve the slip property. In the case of Comparative Example 3 using a silicone-based slipping agent, the slipping property was improved, but the solvent adhesion was reduced to an unusable level.

In the case of Comparative Example 4 in which no slip agent was used, the coefficient of friction was high and it was difficult to have a slip property. In Comparative Example 5, the friction coefficient was low according to the content of particles in Comparative Example 6, It is not preferable when compared with the embodiment according to the present invention.

INDUSTRIAL APPLICABILITY As described above, the present invention can provide a heat-shrinkable polyester film having improved slipperiness compared to the conventional shrinkable film. That is, a slip coating layer containing a copolyester resin and a wax-based slipping agent is formed on one side or both sides of a polyester base film to control the slip property of the film to improve workability in high-speed labeling in user processes, And improved slippery film with excellent solvent adhesion. As a result, the heat-shrinkable polyester film having improved slipperiness that does not cause any trouble in the sealing process because it can improve the productivity in the high-speed labeling and sealing process than the conventional shrink film, Can be provided.

It is to be understood that the present invention is not limited to the above embodiments and various changes and modifications may be made by those skilled in the art without departing from the spirit and scope of the invention.

Claims (5)

A coating layer applied on at least one side of the polyester base film with a slip coating composition comprising an antistatic composition and a wax-based slipping agent,
Wherein the antistatic composition comprises a copolymerized polyester, a methyl methacrylate copolymer and an alkyl phosphate,
Wherein the slip coating composition comprises an antistatic composition comprising 5 to 20 parts by weight of the methyl methacrylate copolymer and 20 to 60 parts by weight of the alkyl phosphate per 100 parts by weight of the copolymer polyester, And 5 parts by weight of a wax-based slip,
The wax-based slipping agent is a polypropylene-based wax,
Wherein the coating layer has a static friction coefficient of 0.16 to 0.35 and a dynamic friction coefficient of 0.20 to 0.25. The method according to claim 1,
Wherein the coating layer has a surface resistivity of 1 x ¹⁰ &lt; ¹⁰ &gt; / sq or less. The method according to claim 1,
Wherein the dicarboxylic acid component of the polyester base film is terephthalic acid or dimethyl terephthalate and the diol component is selected from the group consisting of 60 to 90 mol% of ethylene glycol and at least one of neopentyl glycol, 1,4-cyclohexanedimethanol, diethylene glycol, propanediol, And 10 to 40 mol% of at least one diol selected from the group consisting of butanediol. The method according to claim 1,
Wherein the heat shrinkable polyester film has a shrinkage ratio in a main shrinkage direction measured after immersing in hot water at 90 캜 for 10 seconds of 30% or more. 5. The method according to any one of claims 1 to 4,
Wherein the thickness of the coating layer is 0.5 to 5.0 占 퐉.