KR20170080515A - Release film and manufacturing method thereof - Google Patents

Abstract

The present invention relates to a release film and a method for producing the same. More particularly, the present invention relates to an in-line coating release film for use in electronic materials such as a multilayer ceramic capacitor (MLCC), a polarizer protection film, and an OCA (Optically Clear Adhesive) film.

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention [0001] The present invention relates to a release film,

The present invention relates to a release film and a method for producing the same. More particularly, the present invention relates to an in-line coating release film for use in electronic materials such as a multilayer ceramic capacitor (MLCC), a polarizer protection film, and an OCA (Optically Clear Adhesive) film.

The release film is used for an adhesive surface protection film for use of an adhesive or an adhesive, a carrier sheet for supporting a flexible material, or the like.

On the other hand, the shape of the pressure-sensitive adhesive or adhesive is changed from liquid to sheet in order to diversify the use and variety of optical products and to improve the productivity.

The release film protecting this sheet shape temporarily protects the adhesive surface of the adhesive product from contamination due to dust, debris, moisture or other contaminants until the label is used, and then separates from the adhesive surface immediately before use of the adhesive product. Therefore, the release film is provided with a coating layer which can impart peelability to the surface of the product and at the same time can give adhesion to the product.

The release film may be prepared into a solvent type or an emulsion type depending on the coating method or use. In general, the emulsion type composition has a low stability and a high latent heat of vaporization due to the use of water as a dispersion medium, which requires a high temperature curing.

The release film applied to the off-line coating has a low drying process temperature and a short length of the drying line, so that a solvent-based or solvent-free coating composition is mainly used.

The release film applied to the in-line coating is mainly used in an emulsion-type composition because there is a risk of explosion when the solvent is used in the PET film-forming process.

The reason why such an emulsion-type composition is applied to an in-line coating is that the temperature of the Tenter process is high and sufficient crosslinking is possible. However, since the silicone emulsion composition for in-line coating needs to be able to be stretched, there is a problem that the raw materials to be used are limited, so that the in-line coated silicone release film is extremely limited.

In order to solve the above problems, various attempts have been made to provide a composition for in-line coating and a release film using the composition, which can be easily peeled off at the initial stage, have a sufficient curing reaction, have a high residual adhesive ratio and a low rear-

Korean Patent Laid-Open Publication No. 2014-0080659 discloses a technique for adjusting the peeling force ratio including an organopolysiloxane resin containing a hydroxyl group or an alkenyl group as a peel strength adjusting agent. However, the above technique can achieve the delamination, that is, the releasing force can reach up to about 20 gf / inch, and it is difficult to achieve the delamination, that is, the releasing force of 10 gf / inch or less. In addition, the in-line coating method has a limitation in heightening the coating thickness, and as the thickness of the coating layer increases, the winding-off property after manufacture lowers, the appearance of the coating becomes poor and the cost of the coating material increases. Research and development are required.

Disclosure of the Invention The present invention has been made to solve the above-mentioned problems, and it is an object of the present invention to provide a releasing film having an initial release force of less than 10 gf / inch, And a method for producing the same.

Another object of the present invention is to provide a release film which is excellent in winding property and residual adhesion, and can minimize a deviation in releasing force, and a method for producing the same.

The present invention relates to a release film and a method for producing the same.

The present invention provides a release film comprising a polyester base film and a release coating layer formed on one or both sides of the base film. In this case, the release coating layer includes silicon beads having an average particle diameter of 0.05 to 2 탆, and is characterized by satisfying the following formulas 1 to 3.

[Formula 1]

R _i ≤ 10

[Formula 2]

| R _f - R _i | ≤ 20

[Formula 3]

| R _f-max - R _f-min | 1.2

In the above formulas 1 to 3, R _i is the releasing force measured after standing at 55 ° C for 24 hours, R _f is the releasing force measured after standing at 55 ° C for 240 hours, R _{f -max} is 55 ° C , And R _f -min is the minimum value of the release force measured five times after being left at 55 ° C for 240 hours.

In the release film according to an embodiment of the present invention, the release coating layer may be formed of a release coating layer composition comprising a silicon compound composition and silicon beads dispersed in an alcohol. At this time, the silicon beads can be mixed with the release coating layer composition in a dispersed state using any one or more alcohol selected from anhydrous ethanol and isopropyl alcohol anhydride as a dispersion medium.

In the release film according to an embodiment of the present invention, the silicon compound composition may include a silicon compound, a platinum-based catalyst, and a silicon-based wetting agent.

The silicon compound may include any one or two or more compounds selected from the following Formulas (1) to (3) and a compound represented by Formula (4).

[Chemical Formula 1]

In the above formula (1), n is 20 to 3000, m is 1 to 500, and n + m is 21 to 3000.

(2)

In the above formula (2), x is 1 to 3000.

(3)

Wherein R ₁ , R ₂ , R ₃ and R ₄ each independently represent -CH═CH ₂ , - (SiC ₂ H ₆ O) _k CH═CH ₂ , - (SiC ₂ H ₆ O) _k ( CH ₂ ) _l CH = CH ₂ , k and l are each independently 0 to 300, y is 20 to 3000, z is 1 to 500, and y + z is 21 to 3000.

[Chemical Formula 4]

In Formula 4, a is from 1 to 150, b is from 3 to 300, and a + b is from 5 to 300.

In addition,

a) melt-extruding a polyester resin to prepare a sheet;

b) longitudinally stretching the sheet;

c) applying the release coating layer composition comprising the silicon compound composition and the silicon bead on one or both sides of the sheet of step b) by in-line coating method;

d) drying and preheating the c) step sheet, and then stretching in the transverse direction to produce a release film; And

e) heat treating the release film;

And a method for producing a release film.

In the method for producing a release film according to an embodiment of the present invention, the release coating layer composition may include separately mixing silicon beads dispersed in alcohol.

In the method of manufacturing a release film according to an embodiment of the present invention, the silicon bead may have an average particle diameter of 0.05 to 2 탆.

In the method for producing a release film according to an embodiment of the present invention, the silicon compound composition may include a silicon compound, a platinum-based catalyst, and a silicon-based wetting agent.

In the method for producing a release film according to an embodiment of the present invention, drying and preheating may be performed at a temperature of 140 ° C or lower in step d).

In the method for producing a release film according to an embodiment of the present invention, the stretching in step b) or step d) may be carried out at 80 to 150 ° C.

The release film according to the present invention can achieve a peelability of 10 gf / inch or less even when the inline coating method is applied. In addition, there is an advantage that the releasing force is less change with time, the appearance of the coating is excellent, the deviation of releasing force is minimized, and the peeling stability is excellent, and the defect caused by peeling of the pressure- .

Through the realization of the above properties, the release film according to the present invention can be applied to various fields such as a capacitor, a photographic film, a label, a pressure sensitive tape, a decorative laminate, a transfer tape, a polarizing plate and a ceramic green sheet have.

Hereinafter, the present invention will be described in more detail with reference to specific examples. It is to be understood, however, that the invention is not limited to the disclosed embodiments, but, on the contrary, is intended to cover various modifications and equivalent arrangements included within the spirit and scope of the appended claims.

Also, unless otherwise defined, all technical and scientific terms have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs. The terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the invention.

It is also to be understood that the singular forms as used in the specification and the appended claims are intended to include the plural forms as well, unless the context clearly indicates otherwise.

The release film according to the present invention comprises a polyester base film and a release coating layer formed on one or both sides of the polyester base film, wherein the release coating layer comprises silicon beads having an average particle diameter of 0.05 to 2 탆, 3 < / RTI >

[Formula 1]

R _i ≤ 10

[Formula 2]

| R _f - R _i | ≤ 20

[Formula 3]

| R _{f -max} - R _{f -min} | 1.2

In the above formulas 1 to 3, R _i is the releasing force measured after standing at 55 ° C for 24 hours, R _f is the releasing force measured after standing at 55 ° C for 240 hours, R _{f -max} is 55 ° C , And R _{f -min} is the minimum value of the release force measured five times after being left at 55 ° C for 240 hours.

In the present invention, the polyester base film may be composed of a polyester resin obtained by condensation polymerization of an acid component containing a dicarboxylic acid as a main component and a glycol component containing an alkyl glycol as a main component.

As the main component of the dicarboxylic acid, terephthalic acid or an alkyl ester thereof or a phenyl ester thereof is mainly used, but a part of the dicarboxylic acid is used as a main component of the dicarboxylic acid such as isophthalic acid, oxyethoxybenzoic acid, adipic acid, sebacic acid, 5-sodium sulfoisophthalic acid Can be used in place of the bifunctional carboxylic acid or an ester-forming derivative thereof.

The glycol component is mainly composed of ethylene glycol, but a part of the glycol component may be, for example, propylene glycol, trimethylene glycol, 1,4-cyclohexanediol, 1,4-cyclohexanedimethanol, 1,4-bisoxyethoxybenzene , Bisphenol, and polyoxyethylene glycol. If the content is small, a monofunctional compound or a trifunctional compound may be used in combination.

In the present invention, when the release coating layer satisfies the following formulas 1 to 3, the releasing force does not change with the lapse of time, and uniform adhesion characteristics can be achieved.

[Formula 1]

R _i ≤ 10

[Formula 2]

| R _f - R _i | ≤ 20

[Formula 3]

| R _{f -max} - R _{f -min} | 1.2

In the above formulas 1 to 3, R _i is the releasing force measured after standing at 55 ° C for 24 hours, R _f is the releasing force measured after standing at 55 ° C for 240 hours, R _{f -max} is 55 ° C R _{f -min} is the minimum value of the release force measured five times after being left at 55 ° C for 240 hours.

The above formula (1) indicates the peelability of the releasing film, and if it is out of the above range, it is difficult to achieve the releasability of the peel strength required in the present invention. Although the lower limit of the above-mentioned formula (1) is not particularly limited, it is preferable that the releasing force R _i is 3 or more. When the releasing force R _i is less than 3, the initial releasing force is too large and the adhesive property to the adherend may not be properly developed.

Equation (2) implies a change over time in the releasing force. The smaller the change over time is, the better the control is possible because the product can be stored for a long time after final production and can be used, and a uniform peeling force is exhibited when peeling off the releasing film. Although the lower limit of the formula (2) is not particularly limited, it is preferable that the change in the releasing force with time (R _f - R _i |) is 10 or more. When the change of the releasing force with time is less than 10, it is better because there is no trace of peeling when the film is peeled off from the film at a width of 1,000 mm or more. On the other hand, when the elongation of the releasing force is more than 20, a high releasing force may be exhibited when peeling the film with a width of 1,000 mm or more, so that the peeling of the releasing film may be left on the surface of the green sheet or sheet for electronic materials.

When the deviation of the values of the releasing force measured after standing for 240 hours at 55 캜 is less than 1.2, the deviation of the releasing force can not be felt, Do. On the other hand, if it is more than 1.2, it is possible to sense a release force deviation sensibly, and noise during peeling, that is, peeling and peeling may occur, and the peeling may not be uniformly peeled as a whole.

In order to achieve balance of physical properties, the release coating layer according to the present invention is formed from a release coating composition comprising a silicon compound composition and silicon beads dispersed in an alcohol. The release coating composition is not particularly limited, but may be composed of 10 to 40% by weight of the silicon compound composition, 0.1 to 5% by weight of silicon beads, 5 to 20% by weight of alcohol and a residual solvent. At this time, the silicon beads are preferably mixed with the release coating composition in the form of dispersed using anhydrous ethanol, isopropyl alcohol anhydride or the like as a dispersion medium.

The silicon compound composition may include a silicon compound, a platinum-based catalyst, and a silicon-based wetting agent.

The silicon compound may include any one or two or more compounds selected from the following Formulas (1) to (3) and a compound represented by Formula (4).

[Chemical Formula 1]

 In the above formula (1), n is 20 to 3000, m is 1 to 500, and n + m is 21 to 3000.

(2)

 In the above formula (2), x is 1 to 3000.

(3)

Wherein R ₁ , R ₂ , R ₃ and R ₄ each independently represent -CH═CH ₂ , - (SiC ₂ H ₆ O) _k CH═CH ₂ , - (SiC ₂ H ₆ O) _k ( CH ₂ ) _l CH = CH ₂ , k and l are each independently 0 to 300, y is 20 to 3000, z is 1 to 500, and y + z is 21 to 3000.

[Chemical Formula 4]

In Formula 4, a is from 1 to 150, b is from 3 to 300, and a + b is from 5 to 300.

The compounds represented by the above formulas (1), (2) and (3) are each a prepolymer state of the siloxane structure as a subject of the release coating layer. In addition, the compound represented by Formula 4 reacts with Formulas 1 to 3 as a curing agent to form PDMS (Polydimethylsilicone Resin). The vinyl group of the formulas 1 to 3 reacts with the silane group of the formula 4 and the silane group of the formula 4 reacts randomly with the silane group (Si-H) and Si-CH ₃ Si-H is advantageous in that the reaction rate is faster than that of the curing agent in which only Si-H is continuous, because it is low in sterical hindrance, and it does not hinder the physical properties of the polyester base film of the present invention.

Commercialized examples of the compound represented by the above formula (1) include, but are not limited to, Dehesive 490 from Wacker Chemie AG. Commercial examples of the compound represented by Formula 2 include Dehesive 430 from Wacker Chemie AG, KM3951 and KM3952 from Shin-etsu, and the like. Commercialized examples of the compound represented by the above formula (3) include Dehesive 440 from Wacker Chemie AG, SYL-OFF 7920 and SYL-OFF 7924 from Dowcorning, and the like. Commercialized examples of the compound represented by Formula 4 include Crosslinker V72 and Crosslinker V15 from Wacker Chemie AG, but are not limited thereto.

In the present invention, the platinum-based catalyst promotes the reaction between the vinyl groups of the polydimethylsiloxane of the compounds represented by Chemical Formulas 1 to 3 and the hydrogen of the polyhydroxylsiloxane of the chemical compound represented by Chemical Formula 4 to bond the coating layer to the substrate film And thus enhances the adhesion, that is, the adhesion. Such a platinum catalyst is preferably contained in an amount of 1 to 20 ppm in the total silicon compound composition. When the above range is satisfied, the effect of improving the reactivity is increased, and the production cost can be reduced. Commercial examples of the platinum-based catalysts include, but are not limited to, EM440 from Wacker Chemie AG. Commercial examples of the silicone-based wetting agent include, but are not limited to, Q2-5211 of Dow Corning.

In the release coating composition according to the present invention, the solid content of the compound of Formula 1, 2 or 3 may be 5 to 25% by weight, preferably 8 to 16% by weight. When the above range is satisfied, the surface of the polyester film can be sufficiently coated, and the residual conversion ratio can be effectively controlled by increasing the reaction conversion ratio.

In addition, the solid content of the compound of Formula 4 may be 0.5 to 5 wt%, preferably 0.8 to 2 wt%. When the above range is satisfied, the release coating layer can be sufficiently cured, and the change in releasing force over time can be reduced without an unreacted silane group.

The solid content of the platinum-based catalyst may be 0.001 to 3% by weight, preferably 0.005 to 0.1% by weight. In this range, the effect of adding the catalyst is sufficiently exhibited, and the unevenness of releasing force can be suppressed.

It is further preferable that the solid content of the silicone based wetting agent is 0.1 to 3% by weight, preferably 0.5 to 2% by weight. When the above range is satisfied, it is possible to prevent the occurrence of coating unevenness while lowering the haze of the film to be produced.

In one preferred embodiment, the silicon compound composition comprises the compound of Formula 1, the compound of Formula 4, the platinum-based catalyst, and the silicone-based wetting agent, or the compound of Formula 2, the compound of Formula 4, A wetting agent, a compound of Formula 3, a compound of Formula 4, a platinum catalyst, and a silicone-based wetting agent. More preferably, the silicon compound includes a combination of the compounds represented by the general formulas (2) and (4), thereby reducing the deviation of the releasing force and improving the residual adhesive force.

In the present invention, the silicon compound composition may include 10 to 40 wt% of 100 wt% of the total release coating layer composition. In this range, it is possible to improve the adhesion between the base film and the coating layer and to suppress the waste of the unreacted silicon compound.

In the present invention, the silicon beads have a low peeling force and a uniform surface roughness, and the contact area with the adhesive is reduced to lower the releasing force. In this case, the average particle size of the silicon beads may be 0.05 탆 to 2 탆. If the thickness is less than 0.05 탆, the effect is insignificant. If the thickness is more than 2 탆, stability of the liquid solution may be deteriorated due to precipitation of silicon beads, and the appearance of the coating may be poor.

The silicon beads were analyzed by a moisture analyzer at a temperature of 120 DEG C for 30 minutes under conditions of Coefficient of Variance (CV = Standard Size of Silicon Beads / Average Size of Used Silicon Beads) The measured Moisture Contents may be less than 0.6%. When the coefficient of variation of the silicon beads is more than 20, the difference in the size distribution according to the production lot of the silicon beads increases, so that the difference in the coatability and the running property may increase, and the reproducibility of the product may deteriorate. Also, when the moisture content exceeds 0.6%, it can be an inhibiting factor of the silicon reaction depending on the moisture.

In the present invention, the silicon beads may include 0.1 to 5 wt% of 100 wt% of the total release coating layer composition. If the content is less than 0.1% by weight, roughness is not formed and the releasing force can not be lowered. If the content is more than 5% by weight, the reaction conversion rate may be lowered and the appearance of the coating may be poor.

In the present invention, the silicon beads are dispersed in alcohol to exhibit a more uniform dispersibility, and a desired property of increasing the physical properties can be realized by combining with other components. At this time, the alcohol is preferably anhydrous alcohol, more preferably any one selected from anhydrous ethanol and anhydrous isopropyl alcohol, or a mixture thereof. This is because the diameter of the silicon bead itself is small and the surface of the silicon is hydrophobic, so that when the water is used as the dispersing solvent, the dispersibility is further lowered. At the same time, the alcohol according to the present invention is characterized in that anhydrous alcohol is used, unlike the case of containing 20 to 30% of water. When such anhydrous alcohol is used, the dispersion of the silicon beads is further improved, and appearance defects can be prevented from occurring.

The release film according to the present invention may have a residual adhesion ratio of 90% or more.

It is possible to judge that the unreacted materials of the release film are low in the range of the residual adhesion ratio of 90% or more, and it is preferable because the amount of unreacted materials of the release film transferred to the final product after the post-processing is small.

In the release film according to the present invention, the polyester base film may have a thickness of 10 to 200 탆, more preferably 10 to 50 탆, and the thickness of the release coating layer may be 0.01 to 0.5 탆, more preferably 0.1 to 0.3 탆 However, the present invention is not limited thereto.

The method of manufacturing a release film according to the present invention maximizes product physical properties through control of the surface properties of a base film and can reduce costs as an in-line coating process is introduced, thereby being economical and maximizing productivity.

The method for producing a release film according to the present invention comprises

a) melt-extruding a polyester resin to prepare a sheet;

b) longitudinally stretching the sheet;

c) applying the release coating layer composition comprising the silicon compound composition and the silicon bead on one or both sides of the sheet of step b) by in-line coating method;

d) drying and preheating the c) step sheet, and then stretching in the transverse direction to produce a release film; And

e) heat treating the release film;

.

At this time, the release coating layer composition is characterized in that silicon beads dispersed in alcohol are separately mixed.

In the step c), the release coating composition may be applied using a gravure roll. If a gravure coating roll is used, the release coating composition can be applied in a uniform thickness.

Preferably, the drying and preheating is performed at a temperature of 140 ° C or less, more specifically 110 to 140 ° C. If the temperature exceeds 140 ° C, the deviation of the releasing force may increase and the uniformity may be greatly reduced.

Also, it is preferable that the stretching at the step b) or d) is carried out at 80 to 150 ° C. If the temperature is lower than 80 ° C, sufficient heat for stretching is not sufficient and stretching does not occur properly. If the temperature is higher than 150 ° C, heat wrinkles or orange peel may occur on the film.

In the step d), the stretching ratio during stretching is not limited to a great extent, but stretching may be 3 to 5 times in the machine direction (MD) and the width direction (TD), respectively. The thickness uniformity of the film produced in the above range can be maintained, and the breakage of the film can be suppressed.

In the step e), the heat treatment may be carried out at 230 to 250 ° C. If the temperature is lower than 230 ° C, the release coating layer may not sufficiently react and may be pushed. When the temperature exceeds 250 ° C, heat wrinkling and orange peel may occur.

Hereinafter, the present invention will be described in more detail with reference to the following examples. However, the present invention is not limited to the following examples.

The following physical properties were measured as follows.

1) Coating uniformity measurement

 When the area of the portion of the polyester releasing film where the release layer is not formed is 1% or less of the area of the base film, the result is good.

2) Coating thickness

The silicone content of the release layer was measured with a calibrated XRF instrument (Oxford LX3500) and converted to the coating thickness.

3) Release force

The release force was measured using a TESA 7475 as a standard tape according to the method of FINAT 10.

(1) Release force R _i

TESA 7475 was placed on the release coating layer of the films prepared in Examples and Comparative Examples, and was rubbed back and forth twice using 2 Kg of rubber roll, and then 5 samples of 50 mm x 15 cm size pieces were prepared at intervals of 10 cm. The prepared sample was allowed to stand at 55 DEG C for 24 hours under a load of 70 g / cm < 2 > and subjected to peel peel evaluation at 180 degrees using Peel Tester (Chem Instrument, AR-1000). The peeling speed was 300 mm / min. The release force of the five samples was measured and the average value was shown.

(2) The releasing force R _f

TESA 7475 was placed on the release coating layer of the films prepared in Examples and Comparative Examples, and was rubbed back and forth twice using 2 Kg of rubber roll, and then 5 samples of 50 mm x 15 cm size pieces were prepared at intervals of 10 cm. The prepared sample was allowed to stand at 55 DEG C for 240 hours under a load of 70 g / cm < 2 > and subjected to peel peel evaluation at 180 degrees using Peel Tester (Chem Instrument, AR-1000). The peeling speed was 300 mm / min. The release force of the five samples was measured and the average value was shown.

(3) Change over time of release force (| R _f - R _i |)

The difference between the releasing force R _f and the releasing force R _i is taken as a change with time in the releasing force.

(4) Deformation force deviation (| R _f-max R _{f -min} |)

The releasing force R _f In the measurement, the difference value was calculated by setting the maximum value of the release force measured five times as R _{f -max} and the minimum value as R _f-min .

4) Residual adhesion rate

(1) First Adhesive Force: A Nitto 31B tape, which is a standard tape, was left to stand at 70 캜 for 24 hours, followed by lapping it on a Teflon sheet and repeatedly pressing twice with 2 kg of rubber roll. The adhesive strength of the lapped sample Nitto 31B Tape was measured using a 180-degree film tester (Chem Instrument AR1000).

(2) Second Adhesive Force: A Nitto 31B tape as a standard tape was adhered to the release coating layer of the film prepared in Examples and Comparative Examples, and left at 70 DEG C for 24 hours under a load of 70 g / cm < I removed the Nitto 31B tape. The detached Nitto 31B tape was again put on a Teflon sheet and pressed twice with 2 kg of rubber roll. The adhesive strength of the lapped sample Nitto 31B Tape was measured using a 180-degree film tester (Chem Instrument AR1000).

The residual adhesive force was measured as shown in Equation 4 below. The unit is gf / inch, and satisfies when the residual adhesion rate is 90% or more.

[Formula 4]

Residual tack ratio = (second tack / first tack) x 100

The compositions used in the following Examples and Comparative Examples are as follows.

Coating solution 1: 49.99 wt% of polydimethylsiloxane (DEHESIVE (R) 490, Wacker Chemie AG) as a silicon compound of formula (1) and 0.01 wt% of platinum catalyst (EM440, Wacker Chemie AG) as a solid content, Wherein the total solids content is 50% by weight.

Coating solution 2: 49.99% by weight of a polydimethylsiloxane (Shin-Etsu, KM3951) as a silicon compound of formula (2) in solid content and 0.01% by weight of a platinum catalyst (EM440 by Wacker Chemie AG) as a solid content and the total solids content 50% by weight.

Coating solution 3: A hydrogen silane compound (Wacker Chemie AG, Crosslinker V15, a compound having a of 5 in the formula (4), b of 95 and a weight average molecular weight of 4000 g / mol) was mixed with the silicon compound of the formula (4) 50 wt%.

The weight average molecular weight is measured by gel chromatography (GPC) using styrene as a standard material.

Coating solution 4: A silicone-based wetting agent, the composition of which is Dow Corning, Q2-5212 with a solids content of 80% by weight.

Coating solution 5: 49.99% by weight of a solid content of SYL-OFF ^占 7920, Dow Corning company containing a polydimethylsiloxane of the formula (3) and a hydrogen silane compound of the formula (4), a solid content of platinum catalyst (Wacker Chemie AG, EM440) By weight to 0.01% by weight, and a total solids content of 45% by weight.

[Example 1]

20% by weight of the coating solution 1, 1% by weight of the coating solution 3, 0.5% by weight of the coating solution 4, 0.5% by weight of silicon beads and residual water was used as a solvent. Further, the silicon beads were dispersed separately using anhydrous ethanol, and then mixed to prepare a liquid. At this time, the content of anhydrous ethanol is 10% by weight in the total coating liquid composition.

Then, 1,000 g of dimethyl terephthalate, 576 g of ethylene glycol, 300 ppm of magnesium acetate and 400 ppm of trimethyl phosphate were added to the reactor and the ester exchange reaction was carried out while methanol was flowing out. Thereafter, condensation polymerization was carried out under a vacuum of 0.3 torr at 285 DEG C to obtain a polyester chip having an intrinsic viscosity of 0.61.

The polyester chips were melt-extruded at 280 DEG C and then quenched at 24 DEG C using a large-sized roll to obtain a polyester sheet. The resulting polyester sheet was stretched 3.5 times in the longitudinal direction at 110 DEG C and the coating film was applied to the cooled film using a gravure coater.

After drying and preheating at 125 DEG C, the film was stretched 3.5 times in the transverse direction to prepare a biaxially stretched film. The obtained biaxially stretched film was heat-treated at 240 캜 to obtain a release film having a thickness of 25 탆. The physical properties of the resulting release film were measured and are shown in Table 2 below.

[Examples 2 to 9 and Comparative Examples 1 to 3]

A release film was prepared in the same manner as in Example 1, except that the composition ratio of the coating liquid, the preheating temperature, and the like were changed as shown in Table 1 below. The properties of the prepared release films were measured and are shown in Table 2 below.

Releasing coating layer composition Preheat temperature (℃) after application of coating liquid Coating liquid Silicon bead One 2 3 4 5 Dispersed solvent
Kinds Average particle diameter
(탆) Addition amount
(weight%) Example 1 20 - One 0.5 - ET 0.5 0.5 125 Example 2 20 - One 0.5 - IPA 0.3 One 125 Example 3 20 - One 0.3 - IPA 0.1 3 120 Example 4 - 20 One 0.5 - ET 0.5 0.5 125 Example 5 - 20 One 0.5 - IPA 0.3 One 125 Example 6 - 20 One 0.3 - IPA 0.1 3 120 Example 7 - 20 One One - IPA One 0.05 130 Example 8 20 - One One - IPA 2 0.05 130 Example 9 0 0 0 0.5 20 IPA 0.5 0.05 125 Comparative Example 1 20 - 1.5 One - - - 0.5 130 Comparative Example 2 20 - One 0.5 - water 0.5 0.5 130 Comparative Example 3 20 - One 0.5 - ET 0.5 0.5 150

In Table 1, ET is anhydrous ethanol and IPA is isopropyl alcohol anhydride.

coating
Uniformity Coating thickness
(탆) R _i
(gf / inch) Release force after aging Residual tack rate
(%) R _f
(gf / inch) Dissimilarity change over time Deviation power deviation Example 1 Good 0.2 4 19 15 One 93 Example 2 Good 0.2 4 18 14 0.9 92 Example 3 Good 0.2 5 21 16 0.9 92 Example 4 Good 0.2 4 17 13 0.5 92 Example 5 Good 0.2 4 15 11 0.9 92 Example 6 Good 0.25 5 19 14 0.3 94 Example 7 Good 0.2 4 18 14 0.4 92 Example 8 Good 0.2 4 18 14 0.6 91 Example 9 Good 0.2 5 19 14 0.5 93 Comparative Example 1 Bad 0.2 8 35 27 One 95 Comparative Example 2 Bad Can not be measured due to bad appearance Comparative Example 3 Bad 0.2 7 22 15 1.5 92

As can be seen from Table 2, the release film produced by the present invention has good coating uniformity and a low releasing force R _i of 10 or less. Also, the elongation of the releasing force according to Eq. 2 is 20 or less, and the releasing force deviation according to Eq. 3 is 1.2 or less. In addition, it was confirmed that the residual adhesion ratio was 90% or more and the unreacted materials were low.

On the contrary, in the comparative example, the initial releasing force is high and the deviation of the releasing force is large. Particularly, in Comparative Example 2 in which water was used as a dispersion solvent, it was confirmed that the physical properties could not be measured due to defective appearance, and in Comparative Example 3, as the preheating temperature was set to 150 ° C, the deviation in mold releasing force became large, have.

While the present invention has been particularly shown and described with reference to specific embodiments thereof, those skilled in the art will appreciate that such specific embodiments are merely preferred embodiments and that the scope of the present invention is not limited thereby. something to do. It is therefore intended that the scope of the invention be defined by the claims appended hereto and their equivalents.

Claims (11)

A polyester base film and a release coating layer formed on one or both sides of the polyester base film,
Wherein the release coating layer contains silicon beads having an average particle diameter of 0.05 to 2 占 퐉 and satisfies the following formulas (1) to (3).
[Formula 1]
R _i ≤ 10
[Formula 2]
| R _f - R _i | ≤ 20
[Formula 3]
| R _f-max - R _f-min | 1.2
In the above Equations 1 to 3, R _i is the releasing force measured after standing at 55 ° C for 24 hours, R _f is the releasing force measured after standing at 55 ° C for 240 hours, and R _f-max is 55 ° C , And R _f -min is the minimum value of the release force measured five times after being left at 55 ° C for 240 hours. The method according to claim 1,
Wherein the release coating layer is formed from a release coating layer composition comprising a silicon compound composition and silicon beads dispersed in an alcohol. 3. The method of claim 2,
Wherein the alcohol is any one selected from anhydrous ethanol and isopropyl alcohol, or a mixture thereof. 3. The method of claim 2,
Wherein the silicon compound composition comprises a silicon compound, a platinum catalyst, and a silicone-based wetting agent. 5. The method of claim 4,
Wherein the silicon compound comprises any one or two or more compounds selected from the following Formulas (1) to (3) and a compound represented by Formula (4).
[Chemical Formula 1]

In the above formula (1), n is 20 to 3000, m is 1 to 500, and n + m is 21 to 3000.
(2)

In the above formula (2), x is 1 to 3000.
(3)

Wherein R ₁ , R ₂ , R ₃ and R ₄ each independently represent -CH═CH ₂ , - (SiC ₂ H ₆ O) _k CH═CH ₂ , - (SiC ₂ H ₆ O) _k ( CH ₂ ) _l CH = CH ₂ , k and l are each independently 0 to 300, y is 20 to 3000, z is 1 to 500, and y + z is 21 to 3000.
[Chemical Formula 4]

In Formula 4, a is from 1 to 150, b is from 3 to 300, and a + b is from 5 to 300. a) melt-extruding a polyester resin to prepare a sheet;
b) longitudinally stretching the sheet;
c) applying the release coating layer composition comprising the silicon compound composition and the silicon bead on one or both sides of the sheet of step b) by in-line coating method;
d) drying and preheating the c) step sheet, and then stretching in the transverse direction to produce a release film; And
e) heat treating the release film;
≪ / RTI > The method according to claim 6,
Wherein the release coating layer composition comprises separately mixing silicone beads dispersed in an alcohol. The method according to claim 6,
Wherein the silicon bead has an average particle diameter of 0.05 to 2 占 퐉. The method according to claim 6,
Wherein the silicon compound composition comprises a silicon compound, a platinum catalyst, and a silicone-based wetting agent. The method according to claim 6,
Wherein the drying and preheating are carried out at 140 DEG C or lower. The method according to claim 6,
Wherein the b) or d) stretching is carried out at 80 to 150 ° C.