KR102041239B1 - Release film - Google Patents

Abstract

The present invention relates to a release film comprising a coating layer containing polyvinylidene chloride on a polyester base film and a release layer containing vinyl modified silicon.
The release film of the present invention has excellent gas barrier properties, reduces the amount of oligomer deposition from the surface of the release layer, and has an oligomer block characteristic but little change in the release property of the release layer, for optical, electronic and electrical materials, or food. Useful as

Description

Release film {RELEASE FILM}

The present invention relates to a release film, and more particularly, a structure comprising a coating layer made of polyvinylidene chloride and a release layer made of vinyl-modified silicon-containing liquid on a polyester base film, and having excellent gas barrier properties. The present invention relates to a release film having reduced oligomer block characteristics from the surface of the release layer and having a change in release characteristics of the release layer while having oligomer block characteristics.

The release film is a protective film for protecting the adhesive component from the foreign matter or undesired adhesive in the air by attaching a pressure-sensitive adhesive film, and generally has a structure in which a release layer is provided on one surface of the base film.

In general, the release film uses a polyester film as the base film and is composed of a release layer in which polymer silicon is coated.

However, when the release film is used in a high temperature manufacturing process, the oligomers remaining in the base film and the release layer are deposited on the coating surface and transferred to the pressure-sensitive adhesive film, which causes various defects due to the deposited oligomers.

Therefore, in the release film field, a release film having oligomer block characteristics has been steadily required. Accordingly, Patent Document 1 relates to a release film having extremely low oligomer deposition amount and silicone migration and good transparency, wherein two outer layers of polyester are laminated on both sides of a polyester film (base layer). At least one layer of the outer layer-substrate layer-outer layer-release layer having a release layer having a residual adhesiveness of 80% or more on one side of the polyester film, wherein the release layer contains a curable silicone resin, The release film whose polyester surface oligomer precipitation amount is 8 mg / m <^2> or less is disclosed.

Moreover, the release film disclosed by patent document 2 invention is a release film in which the coating layer and the release layer were sequentially provided in the single side | surface of the polyester film extended | stretched in at least one axial direction, The said coating layer is an aluminum chelate compound and / or a zirconium compound. By including, the release film which is 1.5 mg / m <^2> or less of oligomer precipitation amount extracted by dimethylformamide from the surface of a release layer after heat processing at 180 degreeC for 10 minutes is disclosed.

In addition, the release film in Patent Document 3 is composed of a polyester film, a coating layer and a release layer, the amount of precipitation of the oligomer extracted by dimethylformamide from the surface of the release layer after the release film is heat-treated at 180 ℃ for 10 minutes. It is characterized by being 0.6 mg / m 2 or less.

However, in the present invention, the coating layer contains polyvinyl alcohol and, for high crosslinking, uses a silane alkoxy oligomer for the release layer, and thus the degree of crosslinking varies depending on the content thereof, thereby accompanied by a change in release properties.

Therefore, there is another problem that causes a change in the release properties by the component in order to lower the amount of oligomer precipitation in the release film field.

Accordingly, the present inventors have made efforts to improve the conventional problems, and as a result, to form a coating layer and a release layer on the base film, the coating layer is polyvinylidene chloride having excellent characteristics of gas barrier properties without inhibiting the release characteristics By forming an optimized thickness using the present invention, even if a typical release layer having a residual adhesion rate of 60% or more is formed, there is little change in release characteristics, and a release film that realizes oligomer block characteristics by reducing the amount of oligomer deposition from the surface of the release layer is provided. By this, the present invention was completed.

Patent Document 1: Republic of Korea Patent Publication No. 2000-0028755 (published May 25, 2000)

Patent Document 2: Republic of Korea Patent Publication No. 2008-0012298 (published Feb. 11, 2008)

Patent Document 3: Republic of Korea Patent Publication No. 2001-0095231 (Nov. 2001.)

In the present invention, by providing a coating layer and a release layer containing polyvinylidene on the base film in sequence, it has excellent gas barrier properties, and has a change in the release characteristics of the release layer while having an oligomer block characteristic of reducing the amount of oligomer deposition. It is to provide less release film.

In order to achieve the above object, the present invention comprises a polyester base film, a coating layer made of a compound represented by Formula 1 on at least one surface of the base film, and a release layer showing a residual adhesion rate of 60% or more on the coating layer. Provide a release film.

Formula 1

In Formula 1, n is a natural number of 1,000 to 50,000.

More preferably, in the compound, n is 1,000 to 5,000 natural water polyvinylidene chloride.

In this case, in order to realize the physical properties of the release film, the thickness of the coating layer is preferably 0.1 to 10.0 μm.

Thus, the release film satisfies the physical properties of (1) water vapor transmission rate 0.01 to 3 g / ㎡ / day and (2) peeling force 20gf / in or less, in particular, after heat-treated at 180 ℃ for 10 minutes, the surface of the release coating layer The amount of oligomer extracted by the dimethylformamide from the is reduced to 1.0 μg / cm 2 or less to implement the oligomer block characteristics.

In addition, the release film of the present invention further comprises an antistatic agent in at least one of the coating layer and the release layer to realize an antistatic property of less than 1 × 10 ¹⁰ / sq.

The release film according to the present invention can be used in various applications such as electronic and electrical materials, optical, food, etc. by providing a release film having a gas barrier property that does not inhibit the release characteristics, the amount of oligomer precipitation by implementing the oligomer block characteristics It can be minimized and used in high temperature processes.

Hereinafter, the present invention will be described in detail.

The present invention is a polyester base film,

An application layer made of a compound represented by Formula 1 on at least one surface of the base film;

It provides a release film made of a release layer showing a residual adhesion rate of 60% or more on the coating layer.

Formula 1

In Formula 1, n is a natural number of 1,000 to 50,000.

In the release film of the present invention, the base film is not particularly limited, but it is preferable to use a polyethylene terephthalate film which is excellent in heat resistance, chemical resistance and mechanical strength and economical. In particular, polyethylene terephthalate film having a thickness of 10 to 200㎛ is widely used in the art.

In addition, the base film may be applied by changing to a single layer or a laminated base film of two or more layers.

In the release film of the present invention, the coating layer is to use a compound represented by the formula (1), more preferably polyvinylidene chloride of n is 1,000 to 5,000 natural water in the compound.

In this case, the polyvinylidene chloride is a polymer of vinylidene chloride, and is copolymerized with polyvinylidene chloride alone or with vinyl chloride, acryronitrile, acrylate ester, and the like.

In the compound represented by Formula 1, n is a natural number of 1,000 to 50,000, and if the value of n is less than 1,000, there is a problem that uniform coating of the coating layer is difficult and gas barrier property is inferior. There is a problem that uniform coating is difficult because the viscosity of the coating liquid is too high. In addition, a commercial product having a value in the above range can be used.

By containing polyvinylidene chloride as a main component in the coating layer, the gas barrier property is excellent, the oligomer block effect can be expected, and the compatibility with the release layer is also excellent. Therefore, the residual adhesion rate is increased on the coating layer. Even if a typical release layer of 60% or more is coated, there is an advantage in that the change in release characteristics is small.

At this time, in order to implement the physical properties of the release film, the thickness of the coating layer is preferably 0.1 to 10㎛.

In the embodiment of the present invention, when the thickness of the coating layer is 5㎛, the moisture permeability and the amount of oligomer precipitation is further lower to support excellent physical properties, but 0.1 to 10㎛ is preferred.

At this time, if the thickness of the coating layer is less than 0.1㎛, gas barrier properties and oligomer block effect is insignificant, whereas if it exceeds 10㎛, there is a problem that a blocking phenomenon occurs when the coating layer is wound.

In the release film of the present invention, the release layer is obtained by applying a release coating liquid obtained by mixing vinyl modified silicone, hydro-silicon, platinum catalyst and residual organic solvent to one surface of the coating layer, followed by heat curing.

The vinyl-modified silicone is not particularly limited and may be used as long as it is a solvent-based or non-solvent silicone commonly used in the art.

The coating thickness of the release layer is preferably a dry thickness of 0.01 to 0.2㎛, if the thickness is less than 0.01㎛, the effect of reducing the low-speed peeling force of the release layer has a problem that the peeling force at a low speed is increased, 0.2 When the thickness exceeds the thickness of the release layer is too high compared to the coating layer has a problem that the high-speed peeling force is increased.

Hydrogen silicone and platinum catalyst contained in the release coating composition for forming the release layer may be used commercially available products in the art.

In addition, in the release coating composition used to form the release layer, toluene is generally applied to the organic solvent, and at least one organic solvent such as n-hexane, n-heptane, n-octane, etc. may be used to secure coating uniformity. It can be mixed and used.

In the above, the coating method of the coating liquid of the coating layer and the release coating liquid of the release layer is not particularly limited, bar, gravure, comma, die coating and the like can be applied. The release coating liquid applied as a liquid may be cured by releasing the cured release layer by heat curing at a temperature of about 150 ° C. for about 30 seconds in a hot air dryer.

The release film of the structure which consists of a coating layer and a release layer on the above-mentioned base film is formed in the optimized thickness using the polyvinylidene chloride which has an excellent characteristic of gas barrier property, without impairing a release property, and remains adhesive Even if a conventional release layer having a rate of 60% or more is formed, (1) a moisture release rate of 0.01 to 3 g / m 2 / day and (2) a low peel force of 20 gf / in or less can be achieved, so that light peeling is possible.

Particularly, after heat treatment at 180 ° C. for 10 minutes, the amount of oligomer extracted by dimethylformamide from the surface of the release coating layer is reduced to 1.0 μg / cm 2 or less, thereby realizing oligomer block characteristics, which is suitable for high temperature processes. Do.

In addition, the release film of the present invention further comprises an antistatic agent in at least one of the coating layer and the release layer to realize an antistatic property of less than 1 × 10 ¹⁰ / sq.

Hereinafter, the present invention will be described in more detail with reference to Examples.

This embodiment is intended to illustrate the present invention in more detail, and the scope of the present invention is not limited by these examples.

< Example  1>

1. Base Film

A polyethylene terephthalate film (manufacturer: Toray Advanced Materials, product name: XD500) having a thickness of 50 µm was used as the base film.

2. Coating layer

On at least one surface of the base film, a polyvinylidene chloride-containing aqueous solution (solid content 75%) having an n value of 2,000 in the compound represented by Chemical Formula 1 was prepared, and applied to a thickness of 0.5 μm using a bar coater, followed by a hot air dryer. It heat-hardened at 150 degreeC for 30 second, and formed the coating layer.

2. Release layer

Silicone resin (manufacturer: Shin-Etsu, product name: KS-847H) 5% by weight, PEDOT aqueous solution (manufacturer: Heraeus: product name Clevious PT) 20% by weight and toluene on the coating layer With respect to 100 parts by weight of the composition consisting of 75% by weight, a release coating solution containing 0.05 parts by weight of a platinum catalyst (manufactured by Shin-Etsu, product name: CAT-PL-50T) was prepared, applied using a bar coater, and then coated in a hot air dryer. Heat cure at 30 ° C. for 30 seconds to form a release layer to prepare a release film.

< Example  2>

The same procedure as in Example 1 was carried out except that the coating layer was formed using a polyvinyl chloride mixed solution (solid content 75%) produced by copolymerizing polyvinylidene chloride and acrylate in a molar ratio of 2: 1. A release film was prepared.

< Example  3>

A release film was prepared in the same manner as in Example 1, except that the thickness of the coating layer was applied at 5 μm.

< Comparative example  1>

A release film was prepared in the same manner as in Example 1, except that the thickness of the coating layer was applied at 0.05 μm.

< Comparative example  2>

A release film was prepared in the same manner as in Example 1 except that the thickness of the coating layer was applied at 15 μm.

< Comparative example  3>

Example 1, except that the solid content containing 20% by weight of the aluminum chelate compound and 80% by weight of the silane alkoxy oligomer was applied to a coating solution concentration of 5% by weight diluted with a toluene / MEK mixed solvent to form a coating layer. In the same manner as in the release film was prepared.

< Comparative example  4>

Apply a solid solution containing 70% by weight of curable silicone having a dimethyl polysiloxane structure, 2% by weight of a curing agent, and 28% by weight of a silicone base compound having a siloxane structural unit with a mixed solvent of MEK and toluene, and apply a coating solution concentration of 3% by weight. A release film was prepared in the same manner as in Example 1, except that the coating layer was formed.

< Comparative example  5>

By omitting the coating layer forming step in Example 1, to form a release layer with a release coating liquid containing vinyl-modified silicone in the base film to prepare a release film.

< Experimental Example  1> Property Evaluation

With respect to the release films prepared in Examples 1 to 3 and Comparative Examples 1 to 5, physical properties required for the release films were evaluated.

1. Water vapor rate measurement

The moisture permeability of the release films prepared in Examples 1 to 3 and Comparative Examples 1 to 5 was measured using a moisture permeability measuring device (MOCON, PERMATRAN-W MODEL 3/33).

2. Measurement of oligomer amount

The release films prepared in Examples 1 to 3 and Comparative Examples 1 to 5 were heat-treated within 30 minutes at a temperature of 180 ° C., and then an upper open box having a bottom area of 314 mm 2 was formed. 15 ml dimethylformamide (DMF) was charged to the box thus formed, and then left for 3 minutes. The DMF was recovered from the box and the amount of oligomer (μg / cm 2) contained in the DMF was measured by HPLC (High Performance LC) analysis.

3. Peel force measurement

Using the TESA7475 tape, a standard tape widely used in the art, the peeling force of the release films prepared in Examples 1 to 3 and Comparative Examples 1 to 5 was evaluated.

A 2 kg roller was attached to the TESA7475 tape, which is a standard tape, on the release coating surface of the release layer, and aged at room temperature for 24 hours. At this time, the peeling force at the time of peeling at 180 degrees was measured using a measuring instrument (AR-1000 of Chemstrustrument), but the peeling rate was measured at 0.3 m / min and the peeling force (gf / in) was recorded.

4. Antistatic measurement

JIS K7194 standard after the release film prepared in Examples 1 to 3 and Comparative Examples 1 to 5 were installed using an antistatic measuring device (Mitsubishi Co., Ltd .; model name MCP-T600) under a temperature of 23 ° C. and a humidity of 50% RH. The surface resistance was measured based on.

5. Measurement of substrate adhesion

JIS K7194 standard after the release film prepared in Examples 1 to 3 and Comparative Examples 1 to 5 were installed using an antistatic measuring device (Mitsubishi Co., Ltd .; model name MCP-T600) under a temperature of 23 ° C. and a humidity of 50% RH. The surface resistance was measured based on.

6. Residual adhesion rate measurement

After the release-coated measurement sample was stored at 25 ° C. and 65% RH for 24 hours, a standard adhesive tape (Nitto 31B) was attached to the release coating surface, and the sample was pressed for 24 hours at a load of 20 g / cm 2 at room temperature. The tape adhered to the release coating surface was collected without contamination, and then adhered to a flat and clean PET film surface, and then reciprocally compressed with a 2 kg tape roller (ASTMD-1000-55T). Peeling force was measured as follows and the residual adhesion rate was computed from it by the formula (1).

Measuring instrument: chem- [0149] instrument AR-1000

Measuring method: 180 ° peeling angle, peeling rate 0.3 m / min

Equation 1

Residual Adhesion Rate (%) = [Peeling Force of Adhesive Tape Peeled to Coating Surface / Peeling Force of Adhesive Tape Not in Contact with Coating Surface] × 100

7. Measurement of substrate adhesion

In the release films prepared in Examples 1 to 3 and Comparative Examples 1 to 5, the release layer was rubbed 10 times by hand, and thus the release layer was peeled off.

From the results of Table 1, in the case of the release film prepared in Example 1 and Example 2, the moisture permeability is excellent, the amount of oligomer precipitated showed an oligomer block effect of less than 0.1㎛, the surface resistance is excellent antistatic Characteristics were also confirmed. In addition, the coating layer and the release layer were sequentially laminated on the base film, but the substrate adhesion was excellent and showed a low peel force of 20gf / in or less.

In addition, as confirmed in the release film prepared in Example 3, when the coating thickness of the coating layer is 5㎛, the moisture permeability and the amount of oligomer precipitation was lower, showing excellent physical properties.

On the other hand, when the coating thickness of the coating layer is too thin in the release film of Comparative Example 1 could not achieve the moisture-permeable effect and the oligomer block effect, as in the release film of Comparative Example 2, the coating thickness of the coating layer is too In the case of thick, the problem of peeling off the release layer was confirmed by showing disadvantageous physical properties in the substrate adhesion.

In addition, Comparative Example 3 and Comparative Example 4 is a release film according to the composition change of the coating layer, the oligomer block characteristics, but showed a poor moisture permeability, the release film of Comparative Example 5 corresponding to the conventional release film Physical properties such as moisture permeability, oligomer block effect, antistatic properties, etc. were all observed.

As described above, the release film of the present invention forms a coating layer and a release layer on the base film, the coating layer using polyvinylidene chloride having excellent characteristics of gas barrier properties without inhibiting the release characteristics By forming with an optimized thickness, even if a typical release layer having a residual adhesion rate of 60% or more is formed, there is little change in release characteristics, and the oligomer block characteristics can be realized by remarkably reducing the amount of oligomer deposition from the surface of the release layer. Suitable for application.

In addition, due to the antistatic properties, it is possible to solve problems such as dust pollution generated during the process, in particular, the release film of the present invention is superior to the conventional release film gas barrier properties, excellent oligomer block effect, optical It can be applied to various uses, such as for use, for electronic and electronic materials, and for food.

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

Claims (6)

In the release film consisting of a polyester base film and a release layer exhibiting a residual adhesion of 60% or more,
On at least one surface of the base film, in the compound represented by Formula 1 n is 1,000 to 5,000 natural water containing polyvinylidene chloride containing aqueous solution; Or a polyvinyl chloride mixed solution in which vinylidene chloride and acrylonitrile or acrylate ester are copolymerized; and a release film having a release layer formed on the coating layer is formed by applying a cured coating layer having a coating thickness of 0.1 to 10 μm. ,
The release film is
(1) water vapor transmission rate 0.01 to 3.6 g / ㎡ / day,
(2) peeling force of 20 gf / in or less;
(3) A release film, characterized in that the amount of oligomer extracted by dimethylformamide from the surface of the release layer after heat treatment at 180 ° C. for 10 minutes is 0.1 μg / cm 2 or less.
Formula 1

delete delete delete delete The release film according to claim 1, wherein an antistatic agent is further contained in at least one of the coating layer and the release layer to have a surface resistance of less than 1 × 10 ¹⁰ / sq.