KR20090005437A - Polyester release film and manufacturing method thereof - Google Patents

Abstract

A polyester release film is provided to improve the cohesive power between a polyester base film and a silicon release layer by optimizing the contact angle of a silicon release fluid coated on the polyester base film to 30-60. A polyester release film comprises a polyester base film and a silicon release layer. The silicon release layer is manufactured by coating one side of the base film with silicon release fluid containing a polyether-modified polydimethyl siloxane. When the silicon release fluid is dropped on the base film, the contact angle (A) of the release fluid satisfies the chemical formula: (30<=A<=).

Description

Polyester release film and its manufacturing method {POLYESTER RELEASE FILM AND MANUFACTURING METHOD THEREOF}

The present invention relates to a polyester release film and a method for producing the same, more specifically, a polyester base film; And a silicone release layer coated on at least one surface of the base film with a silicone release solution containing polyether-modified polydimethylsiloxane. However, when the silicone release solution is added to the base film, the contact angle of the release solution is optimized. The present invention relates to a polyester release film having improved physical properties and a method of manufacturing the same.

In general, polyester films are used as substrates in various applications because of their excellent mechanical strength, dimensional safety, flatness, heat resistance, chemical resistance, optical properties, and the like in terms of cost performance.

In addition, the polyester release film coated with a silicone component is mainly used for high-grade applications requiring a beautiful appearance, high strength, high transparency, chemical resistance. In particular, the polyester release film coated with the silicone component is used as a protective-polarizing plate release, retardation plate release, polarizing plate protection wave of the polarizer or the retardation plate-related pressure-sensitive adhesive, and is used for various release applications such as ceramic release and high-grade label release.

In general, a polyester release film coated with a silicone component is composed of a silicone release layer coated with a silicone component on a polyester base film, and many studies have been conducted to improve adhesion between the base film and the silicone release layer.

As a representative method for improving the interfacial adhesion between the polyester base film and the silicone release layer, the surface of the plastic film used as the base material is chemically treated by corona treatment, plasma treatment, etc. to increase the surface tension to release the silicone-containing release liquid. To improve the wettability of a polyester or as a polyester base film, a polymer having high polarity such as modified affinity polyester, partially hydrolyzed ethylene-vinylacetate copolymer, special acrylic copolymer and polyvinyl butyral is used. Doing.

In addition, as a method for improving the interfacial adhesion between the polyester base film and the silicone release layer, there has been disclosed a technique using an additive for improving the adhesion and a water-dispersible silicone resin that ensures the stability of the curing system. 2005-120253, U.S. Patent No. 4047585, U.S. Patent No. 4677160, Japanese Patent Application Publication No. 64-005838, European Patent Application Publication No. 0527080, United States Patent Application Publication No. 572483 and United States Patent Application Publication No. 5728339] .

On the other hand, Japanese Patent Laid-Open No. 2004-73930 reported a water contact angle (water = 105) through evaluation of physical properties of a polyester release film. However, the water contact angle refers to a contact angle that drops pure water onto the release layer after the release film is completed. Since the water contact angle exceeds 90 degrees irrespective of the type of liquid solution, it is difficult to limit the range. However, it cannot be directly related to the crude liquid properties. That is, based on the water contact angle, the adhesive relationship between the polyester base film and the silicone release layer cannot be directly related.

Accordingly, the present inventors have been devised to improve the physical properties of the polyester release film, by optimizing the contact angle of the silicone release liquid coated directly on the polyester base film, it is related to the improvement of adhesion between the polyester base film and the silicone release layer By revealing, the present invention was completed.

It is an object of the present invention to provide a polyester release film having improved physical properties, in particular, an adhesive force between a polyester base film and a silicone release layer, and a method of manufacturing the same.

In order to achieve the above object, the present invention is a polyester base film; And a silicone release layer coated on at least one surface of the base film with a silicone release solution containing polyether-modified polydimethylsiloxane. However, when the silicone release solution is added to the base film, the contact angle of the release solution (A) The polyester release film which satisfy | fills this 30 <= A <= 60 is provided.

4 to 30% by weight of a mixed component consisting of polydimethylsiloxane having a vinyl group represented by the following Chemical Formula 1 and a hydrogen silane compound represented by the following Chemical Formula 2, a platinum catalyst-containing compound of 0.2 to 3% by weight, an epoxy-based It consists of 0.1-0.3 weight% of a compound, 0.001-0.7 weight% of polyether modified polydimethylsiloxane, and remainder of water.

(In the above, m is an integer of 1 to 100, n is an integer of 20 to 5000, and m + n is 30 to 5000.)

(In the above, a is an integer of 3 to 200, b is an integer of 1 to 120, and 5≤a + b≤200.)

In the silicone release solution, the mixing ratio between the polydimethylsiloxane having a vinyl group represented by the formula (1) and the hydrogen silane compound represented by the following formula (2) is preferably 1: 1 to 5 molar ratio.

The silicon release layer formed by coating the silicon release liquid has a thickness of 0.01 to 10 μm.

The present invention also provides a polyester release film comprising a polyester base film, and at least one surface of the base film, in-line coating a silicone release liquid containing polyether modified polydimethylsiloxane to prepare a silicone release layer. It provides a method of manufacturing.

The silicone mold release liquid is coated on at least one surface of the polyester base film at a coating amount of 0.01 to 10 g / m ² to form a silicone mold release layer having a thickness of 0.01 to 10 μm.

The polyester base film is preferably corona treated through an inline coating process to improve adhesion.

The present invention provides a polyester release film having improved adhesion between the polyester base film and the silicone release layer by optimizing the contact angle of the silicone release liquid coated directly on the polyester base film to 30 to 60.

Hereinafter, the present invention will be described in more detail.

The present invention is a polyester base film; And a silicone release layer coated on at least one surface of the base film with a silicone release solution containing polyether-modified polydimethylsiloxane. However, when the silicone release solution is added to the base film, the contact angle of the release solution (A) The polyester release film which satisfy | fills this 30 <= A <= 60 is provided.

At this time, if the contact angle is less than 30, after drying the silicone release layer, the adhesive strength with the polyester film is lowered, if the contact angle exceeds 60, a problem that the silicone release liquid is not coated on the polyester base film during the coating process occurs do.

Silicone release liquid used in the present invention is 4 to 30% by weight of a mixed component consisting of a polydimethylsiloxane having a vinyl group represented by the formula (1) and a hydrogen silane compound represented by the formula (2), 0.2 to 3 weight of a platinum catalyst-containing compound %, 0.1-0.3 weight% of epoxy-type compounds, 0.001-0.7 weight% of polyether modified polydimethylsiloxane, and remainder of water.

Formula 1

Wherein m is an integer from 1 to 100, n is an integer from 20 to 5000, and m + n is in the range from 30 to 5000. In this case, m and n do not mean a block combination, they merely indicate that the sum of each unit is m, n. Therefore, in the above formula, each unit is randomly coupled or block coupled.

Formula 2

In the above formula, when a is an integer of 3 to 200, b is 1 to 120, and 5 ≦ a + b ≦ 200, an appropriate crosslinking reaction occurs, and a silicone release layer having excellent durability can be obtained. a and b do not mean block joins, they merely indicate that the sum of the units is a and b. Therefore, in the above formula, each unit is randomly coupled or block coupled.

In the silicone release solution, polydimethylsiloxane having a vinyl group represented by the formula (1) and the hydrogen silane compound represented by the formula (2) are used in a mixed form, the mixing ratio is preferably 1: 1 to 5 molar ratio.

In the silicone release solution of the present invention, the platinum catalyst-containing compound is carried out to assist the addition reaction of the formula (1) and formula (2), a preferred example may be selected from the group consisting of organic stone chelate catalysts such as platinum, rhodium and tin. The platinum catalyst-containing compound may be used in an amount of 0.2 to 3% by weight, and if less than 0.2% by weight, the addition polymerization does not proceed at a desired rate. Gelling progresses in between, so-called pot life is shortened and is not suitable for production.

Here, in the formation of the silicone release layer, a peeling control agent may be used in combination with the addition type aqueous curing reaction type by a platinum catalyst in order to control the peelability of the release layer.

In the silicone release solution, the epoxy compound may be used for the purpose of providing solvent resistance and rub-off resistance, and methoxy, ethoxy, acetoxy compound and the like may be used.

It is preferable to use 0.1-0.3 weight% of the said epoxy compound, and when it is less than 0.1 weight%, it is not preferable to provide sufficient adhesive force with polyester, and when it exceeds 0.3 weight%, polydimethyl siloxane and a hydride are exceeded. It is not preferable to increase the peeling force by excessively suppressing the reaction site disturbance, the problem of the wettability characteristics, and the silicone film flexibility of the rosen polysiloxane.

The present invention is characterized by using 0.001 to 0.7% by weight of polyether-modified polydimethylsiloxane as the composition of the silicone release liquid. By using the polyether-modified polymethylsiloxane, the contact angle of the silicone release liquid can be adjusted, but it is preferable to use methoxy or ethoxy as the ether group.

The polyether-modified polymethylsiloxane has compatibility between both oil and aqueous by ether groups, which significantly lowers the surface tension of the release liquid and imparts smoothness of the coated surface. Therefore, as the addition amount of the release liquid increases, the contact angle of the release liquid to the polyester film decreases.

In the embodiment of the present invention, polyether modified polydimethylsiloxanes such as polyethoxy silane and polymethoxy silane, and polyether modified polydimethylsiloxanes of type Π are used. Through the contact angle measurement of this embodiment, the preferred content of the polyether modified polymethylsiloxane having an appropriate surface tension is 0.001 to 0.7% by weight, more preferably 0.01 to 0.5% by weight. At this time, if the amount of polyether-modified polydimethylsiloxane is used less than 0.001% by weight, the surface tension of the release liquid is not enough to lower the leveling property (smoothness of the coating surface), if the content exceeds 0.7% by weight, polydimethyl siloxane The problem of the reaction site disturbance and the wettability of the hydrogen polysiloxane and the excessively suppressed silicone film flexibility resulted in unfavorable results due to the increase in peel force.

In addition to the above composition, the silicone release liquid of the present invention may further contain 0.001 to 0.5% by weight of an antifoaming agent, and the antifoaming agent may be used without particular limitation as long as it can be used to reduce bubbles generated in a conventional release solution preparation process.

The silicone release liquid is applied on a polyester base film in an amount of 0.01 to 10 g / m ² , thereby forming a silicone release layer having a thickness of 0.01 to 10 μm. At this time, when the application amount of the silicone release liquid is less than 0.01 μm, the release property with the adhesive layer is lowered. When the application amount of the silicone release liquid exceeds 10 μm, blocking occurs while the silicon coated surface and the uncoated surface are wound at a constant pressure.

The polyester release film of the present invention has excellent solvent resistance, rub-off property and an increase in peeling force when the contact angle between the polyester film and the silicone release liquid is 30 to 60. And release release properties are uniform, transfer of silicon to the adhesive layer does not occur, especially adhesion between the base film and the silicone release layer is improved, for release films or ceramic mold release related to polarizing plates or retardation plates, high-quality label release It can be used for.

In addition, the present invention provides a method for producing the polyester release film.

More specifically, a polyester base film is prepared, and at least one surface of the base film is in-line coated with a silicone release solution containing polyether-modified polydimethylsiloxane to prepare a silicone release layer.

The polyester base film may be corona treated to improve interfacial adhesion, and by corona treatment, the surface tension may be increased to improve the wettability of the silicone release liquid. In this case, the present invention may be carried out through inline coating when the polyester base film is treated with corona.

The method of coating on the polyester film is classified into offline coating and inline coating depending on the timing of the coating. The offline coating is stretched and heat set, and the coating is completed after the production of the polyester film is completed. In the manufacturing process of the polyester film, the coating before the end of the stretching and heat setting is a method of drying the coating film through the heat setting process without a separate drying process, it is not only an economically advantageous method, but also forms a coating film at a high temperature Therefore, there is an advantage that a high quality coating film is obtained.

Thus, the method of manufacturing the polyester release film of the present invention can form a silicon release layer by the in-line coating method, it is possible to reduce the cost than the offline manufacturing process.

The silicone release liquid is 4 to 30% by weight of a mixed component consisting of polydimethylsiloxane and a hydrogen silane compound, 0.2 to 3% by weight of a platinum catalyst-containing compound, 0.1 to 0.3% by weight of an epoxy compound, and polyether-modified polydimethylsiloxane 0.001 to It consists of 0.7% by weight and the balance of water and is the same as described above for each composition of the silicone release liquid.

The silicone release liquid is applied on a polyester base film in an amount of 0.01 to 10 g / m ² , thereby forming a silicone release layer having a thickness of 0.01 to 10 μm. At this time, the formation of the silicone release liquid is prepared by in-line coating the silicone release liquid while evaporating the solvent at the same time as the biaxial stretching in the polyester base film manufacturing process.

According to the application amount of the silicone release liquid described above, the thickness of the silicone release layer can be adjusted. If the thickness of the silicone release layer is less than 0.01 μm, the release property with the adhesive layer is lowered. Blocking occurs as the uncoated side is wound at a constant pressure.

At this time, in performing the manufacturing method of the present invention, when the silicone release liquid is added to the polyester base film, the contact angle (A) of the release liquid can produce a polyester release film satisfying 30≤A≤60. have.

The contact angle of the present invention is to prepare a release solution by mixing all the release preparation solution, and then to measure the contact angle when the release solution is dropped on the coated surface of the polyester base film, so that the physical properties of the release preparation solution can be directly related That is, through the contact angle, it is possible to correlate the improved adhesion between the polyester base film and the silicon release layer.

Hereinafter, the present invention will be described in detail by way of examples.

The following examples are merely to illustrate the invention, but the scope of the present invention is not limited to the following examples.

< Example  1>

19 wt% of an addition polymerization type polydimethylsiloxane containing a vinyl group and a hydrogen silane compound (mixing ratio 1: 1 of Chemical Formulas 1 and 2) containing a vinyl group on a corona-treated polyester film, 1 wt% of a platinum catalyst-containing compound, and an epoxy A release solution consisting of 0.2% by weight of the compound and 0.05% by weight of polyethoxy silane used as the polyether-modified polydimethylsiloxane Ι was added and mixed at 20 minute intervals, and coated using a Mayer bar so that the coating amount was 0.10 g / m ^2. Drying at 180 ° C to prepare the polyester release film. At this time, the contact angle was 53.7.

< Example  2>

A polyester release film was prepared in the same manner as in Example 1, except that 0.1 wt% of the polyethoxy silane used as the polyether-modified polydimethylsiloxane Ι in the release liquid was used. At this time, the contact angle was 38.8.

< Example  3>

A polyester release film was prepared in the same manner as in Example 1, except that 0.05% by weight of polymethoxy silane used as polyether-modified polydimethylsiloxane Π in the release liquid was used. At this time, the contact angle was 56.6.

< Example  4>

A polyester release film was prepared in the same manner as in Example 1, except that 0.1% by weight of polymethoxy silane used as polyether-modified polydimethylsiloxane Π in the release solution was used. At this time, the contact angle was 52.9.

< Comparative example  1>

A polyester release film was prepared in the same manner as in Example 1, except that 1% by weight of polymethoxy silane used as polyether-modified polydimethylsiloxane Π in the release solution was used. At this time, the contact angle was 21.

< Comparative example  2>

A polyester release film was prepared in the same manner as in Example 1, except that 1% by weight of polyethoxy silane used as polyether-modified polydimethylsiloxane I was used in the release liquid. At this time, the contact angle was 21.

< Experimental Example  1>

Physical properties of the polyester release films prepared in Examples 1 to 4 and Comparative Examples 1 and 2 were measured as described below, and are shown in Table 1 below.

One. Contact angle  Measure

When the release liquid used in Examples 1 to 4 and Comparative Examples 1 and 2 was dripped onto the corona treated polyester film, the contact angle of the release liquid was used by using a contact angle measuring instrument (Kyodo Interface Science, model name Dropmaster 300). It was measured by.

2. Peel force  Measure

After attaching the double-sided adhesive tape to the cold-rolled stainless steel plate to rise up the release layer surface of the polyester release film prepared in Examples 1 to 4 and Comparative Examples 1 and 2, the polyester adhesive tape (Nitto 31B) release layer It mounted on the surface of the installation, it crimped | bonded by the 3 kg pressing roller, and it was left to stand for 30 minutes, and peeling force was measured on 180 degree and 0.3mpm conditions, and the average value was obtained 3 times.

3. Love Rub-off property  Measure

After leaving the polyester release films prepared in Examples 1 to 4 and Comparative Examples 1 and 2 for 3 days at 50 ° C. on the day of coating and in the circulating oven, they were strongly pushed several times with a finger to perform a rub-off test. It carried out and confirmed the adhesive characteristic of the hardened silicone release layer and a polyester film. According to the degree of adhesion, when it was not pushed out at all on the coating day or 3 days, it was indicated by?, And the case where adhesion between the layers was pushed was indicated by x.

4. Solvent resistance  Experiment

The silicone release layers of the polyester release films prepared in Examples 1 to 4 and Comparative Examples 1 and 2 were rubbed with a cotton swab with a solvent selected from methyl ethyl ketone, ethyl acetate, toluene, n-hexane or isopropyl alcohol. At this time, the degree of peeling was visually determined, but classified according to the following criteria. At this time, when not peeled off, it was indicated by ◎, the degree of peeling of some was indicated by ○, and the case of peeling off by interlayer separation at the moment of contact with the solvent was indicated by x.

5. Coating

Visual observation was used to evaluate the coating properties of the polyester release films prepared in Examples 1 to 4 and Comparative Examples 1 and 2, depending on the uniformity of the coated release solution and the degree of defects after drying. (Circle) and (x).

As shown in Table 1, when the contact angle between the polyester film and the silicone release liquid is less than 30, the solvent resistance is poor, the rub-off property is poor, the adhesive strength is lowered, and the peeling force is disadvantageous.

On the other hand, when the contact angle is 30 to 60, solvent resistance, rub-off property was excellent and peeling force was increased. Therefore, as the contact angle of the polyester film and the silicone release liquid is adjusted to 30 to 60, the interlayer adhesion is remarkably improved.

In the present invention, the adhesion between the polyester base film and the silicone release layer is improved so that the release film is used as a protective-polarizing plate release, phase difference plate release, polarizing plate protective wave of the polarizing plate or retardation plate-related pressure-sensitive adhesive, for ceramic release, advanced label release It can be usefully used for various release purposes.

While the invention has been described in detail only with respect to the described embodiments, it will be apparent to those skilled in the art that various modifications and variations are possible within the scope of the invention, and such modifications and variations belong to the appended claims.

Claims (9)

Polyester base film; And A silicone release layer coated with a silicone release solution containing polyether-modified polydimethylsiloxane on at least one surface of the base film; wherein the silicone release solution is added to the base film, and the contact angle of the release solution (A) Polyester release film, characterized in that to satisfy the following formula (1). 30≤A≤60 According to claim 1, 4 to 30% by weight of a mixed component consisting of a polydimethylsiloxane having a vinyl group represented by the following formula (1) and a hydrogen silane compound represented by the following formula (2), platinum catalyst-containing compound 0.2 to The polyester release film, characterized in that consisting of 3% by weight, 0.1 to 0.3% by weight epoxy-based compound, 0.001 to 0.7% by weight of polyether-modified polydimethylsiloxane and the remaining amount of water. Formula 1

(In the above, m is an integer of 1 to 100, n is an integer of 20 to 5000, and m + n is 30 to 5000.) Formula 2

(In the above, a is an integer of 3 to 200, b is an integer of 1 to 120, and 5 ≦ a + b ≦ 200.) The method of claim 2, wherein the silicon release liquid is a polydimethylsiloxane having a vinyl group represented by the formula (1) and a mixing ratio of the hydrogen silane compound represented by the formula (2) is 1: 1 to 5 molar ratio Polyester release film. According to claim 1, wherein the thickness of the silicone release layer is coated, the polyester release film, characterized in that 0.01 to 10㎛. To prepare a polyester base film, The at least one surface of the base film, the method of producing a polyester release film according to claim 1, characterized in that to produce a silicone release layer by inline coating a silicone release liquid containing polyether modified polydimethylsiloxane. The method of claim 5, wherein the silicone release liquid is coated on at least one surface of the polyester base film at a coating amount of 0.01 to 10 g / m ² . The method of claim 5, wherein the silicon release layer is formed to a thickness of 0.01 to 10㎛. The compound according to claim 5, wherein the silicone mold release liquid is 4-30% by weight of a mixed compound composed of a polydimethylsiloxane having a vinyl group represented by Chemical Formula 1 and a hydrogen silane compound represented by Chemical Formula 2, and a platinum catalyst-containing compound 0.2. -3 weight%, 0.1-0.3 weight% of an epoxy-type compound, 0.001-0.7 weight% of polyether modified polydimethylsiloxane, and a residual amount of water, The manufacturing method of the said polyester release film characterized by the above-mentioned. The method of claim 5, wherein the polyester base film is corona treated through an inline coating process.