KR101460553B1 - Release film with laminated release layers with crosslink density gradient - Google Patents

Abstract

The present invention relates to a release film which includes release layers having different crosslink density, laminated on a base layer. A release film according to the present invention includes a base layer; first release layer; and a multi-layered release layer in which layers are sequentially laminated on the first release layer, wherein the layers of the multi-layered release layer are sequentially laminated on the first release layer according to a crosslink density gradient. Thus, a release layer having a low crosslink density and a smooth thin film is formed on an outmost side surface of the release film, so that a shock caused during delamination may be smoothly absorbed, thereby providing delamination stability. In addition, the release layer having a high crosslink density and a hard thin film is formed on a surface close to the base layer, so the delamination force over time is prevented from being increased due to physical permeation of an adhesive, therefore stability over time is met, at the same time.

Description

(RELEASE FILM WITH LAMINATED RELEASE LAYERS WITH CROSSLINK DENSITY GRADIENT)

More particularly, the present invention relates to a release film comprising a base layer, a first release layer, and a release layer of a multilayer formed by sequentially laminating on the first release layer, The release layers of the multi-layers sequentially stacked from the first release layer were laminated in accordance with the cross-link density gradient so that the silicone release film was satisfactory in terms of impact absorption during peeling, .

A release film obtained by forming a releasing layer on one surface of a base material substrate such as a polyester film is attached to an adhesive film, an adhesive film or a tape for protecting the film, and is adhered to an undesired adherent until use, It is used to prevent contamination.

Another use of the release film is to prevent the mold and the molding from sticking to each other in a heat press molding process such as a printed wiring board or in-mold molding, or to form a thin ceramic sheet such as a dielectric for a multilayer ceramic capacitor It is also used as a film.

In order to utilize the releasing film for such an application, a releasing layer is formed by applying a polymeric silicone releasing agent or a fluorine releasing agent to various substrates such as a polyester resin and a polyimide resin, and heating or ultraviolet curing the releasing film.

However, since the fluorine-based releasing agent is excellent in heat resistance, peeling property and anti-pollution property, but is expensive, and is difficult to be burned in the post-use disposal process and poisonous gas is generated, the commercially available release film coated with the silicone releasing agent is more high.

As a report on a release film using a silicone release agent, in JP-A-2010-080036, in order to provide a release film which is light in release upon peeling and excellent in durability and stability over time at the time of exposure to the atmosphere, In the vinyl group and the Si-H group of the siloxane involved in the crosslinking reaction, the content ratio of the vinyl group to the Si-H group (Si -H / Si-Vi ratio) on the physical properties of the release film. In other words, the crosslink density is increased by increasing the amount of functional groups in order to increase the silicone resin residual adhesion ratio for the durability and the stability over time.

In general, a silicone release film having a low cross-link density is widely used because of its superior impact absorption when the adhesive is peeled off.

However, in the case of such a silicone release film, the cross-linking density is low, which causes another problem that the peeling force is lowered due to physical penetration of the pressure-sensitive adhesive. Therefore, when a silicone release film having a high crosslinking density is used as in JP-A-2010-080036, it is possible to prevent the physical penetration of the pressure-sensitive adhesive to prevent an increase in the peeling force with time, but the peeling force This is unstable and there is a problem that causes the sound to be superficial.

In the case of a soft release layer, the soft release layer smoothly absorbs the impact when peeled off, so that no sound is produced. In the case of a hard release layer, however, the shock absorption is not smooth, When I lower the sound, it sounds like it is coming out.

That is, if a release film having a high crosslinking density of the release layer is used, it is possible to prevent the physical penetration of the pressure-sensitive adhesive to prevent the increase in the peeling force with time. However, unstable peeling . On the other hand, the release film having a low cross-linking density of the release layer forms a relatively smooth film, so that shock absorption is smooth and stable in the peeling state. However, there arises a problem due to an increase in peeling force over time due to physical penetration of the pressure-sensitive adhesive.

Accordingly, the present inventors have made efforts to solve the problems of the conventional silicone release films, and as a result, they have found that a release film in which a plurality of release layers having different crosslinking densities are laminated is provided, Thereby completing the present invention.

An object of the present invention is to provide a silicone release film in which a release layer of a multilayer having different crosslinking densities is formed.

Another object of the present invention is to provide a release film having at least two release layers different in cross-linking density from each other, the release of which is minimized while the peeling force is minimized while the impact absorption is smooth.

In order to achieve the above object, A first release layer formed on at least one surface of the substrate layer; And a plurality of release layers sequentially layered on the first release layer in accordance with a cross-link density gradient, wherein the release layers having different cross-linking densities are laminated.

In the release film of the present invention, the release layer in which the cross-link density gradient gradually decreases from the high cross-linking density of the first release layer is successively laminated. In a preferred embodiment of the present invention, at least one surface of a base layer is provided with a first release layer; And a second release layer are sequentially laminated on the first release layer and the first release layer has a high crosslinking density with respect to the second release layer. However, the release layers of the multilayer may be changed into a plurality of release layers with different cross- will be.

At this time, in the release film of the present invention, the multi-layer release layer is designed such that the cross-linking density gradually increases from the release layer formed by the addition reaction type silicone release mold composition, and the first release layer has the highest cross- And a release layer are sequentially laminated.

In this case, the silicone mold release composition contains a polyorganosiloxane having a reactor of an addition reaction type silicone resin (Si-R, R is an alkenyl group) and a hydrogel polyorganosiloxane (Si-H) crosslinking agent.

Thus, in order to increase the crosslinking density, the multi-layered release layer of the present invention can be prepared by adding to the addition reaction type silicone mold releasing composition a hydrogel precursor having a hydrogel precursor having at least two hydrogen atoms bonded to silicon atoms in one molecule (Si- H) crosslinking agent.

Wherein the hydrogel polyorganosiloxane crosslinker is selected from the group consisting of dimethylsiloxane / methylhydrogensiloxane copolymers end-capped with dimethylhydrogensiloxy groups, dimethylsiloxane / methylhydrogensiloxane copolymers end-capped with trimethylsiloxy groups, trimethylsiloxane / Siloxane and poly (methylhydrogen-siloxane) end-capped with poly (hydrogen silsesquioxane).

In the present invention, the multi-layered release layer is composed of the hydrolyzed polysiloxane Si-H reactor and the polyorganosiloxane Si-R reactor having the alkenyl group of 1.0? Si-H / Si- The cross-linking density is gradually increased.

At this time, in the case of the release layer designed to have a high crosslinking density, the composition ratio of the Si-H reactor of the hydrotreated polysiloxane and the Si-R reactor of the polyorganosilox having the alkenyl group is 2.0? Si-H / 12.0 < / RTI >

Further, the multi-layer release layer of the present invention is characterized in that the addition reaction type silicone mold release composition further contains a silicone-free silicone release agent having a short chain length in order to increase the crosslinking density.

At this time, it is preferable that the solvent-free silicone release agent satisfies a viscosity of 50 to 5,000 mPa * s in a 30% toluene solution, and that 0.01 to 2 parts by weight of the solventless silicone release agent is contained in 100 parts by weight of the solvent of the addition reaction- .

The present invention can provide a silicone release film having excellent impact absorption upon peeling and little increase in peel strength with time, by forming a multi-layer release layer having a crosslinking density different on the base layer.

The silicone release film of the present invention is formed by forming a rigid releasing layer having high crosslinking density on the surface adjacent to the base layer to provide stability over time and forming a soft releasing layer having a low crosslinking density outside the base layer, And thus it is possible to provide peel stability.

1 is a schematic cross-sectional view of a release film of the present invention,
Fig. 2 shows the result of comparing the rate of change with time with respect to the release film of Example 1 of the present invention,
FIG. 3 shows the result of comparing the rate of change with time with respect to the release film of Example 2 of the present invention,
Fig. 4 shows the result of comparing the rate of change with time with respect to the release film of Example 3 of the present invention.

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

The present invention relates to a substrate layer;

A first release layer formed on at least one surface of the substrate layer; And

And a release layer having a multilayered release layer sequentially laminated on the first release layer in accordance with a cross-link density gradient, the release layers having different cross-linking densities.

And a release layer in which the cross-link density gradient gradually decreases from a high cross-link density of the first release layer.

Fig. 1 is a schematic cross-sectional view of a release film as an example of a preferred embodiment of the present invention, in which a first release layer 21; And a second release layer (22) are sequentially laminated on the release film (1). At this time, the first release layer 21 with respect to the second release layer 22 is formed by a coating liquid having a high crosslinking density.

In the release film of the present invention, by forming a release layer having a plurality of layers having different crosslinking densities on the base layer and arranging a release layer having a low cross-linking density and a soft coating on the outermost side of the release film, So that stable peeling can be performed.

Further, by forming a release layer having a high crosslinking density and a hard coating on a surface close to the substrate layer, the release layer is designed so as to prevent an increase in the peeling force with time due to physical penetration of the pressure-sensitive adhesive.

That is, in the case of a release layer having a high crosslinking density, it is possible to prevent the physical penetration of the pressure-sensitive adhesive to prevent an increase in the peeling force with time. On the other hand, unstable peeling . On the other hand, the release layer having a low crosslink density forms a relatively smooth film, so that shock absorption is smoothly and stably peeled off during peeling, but the peeling force is likely to increase with the physical penetration of the pressure-sensitive adhesive.

Thus, the release film on which the multi-layered release layer having different cross-linking density is formed on the base layer of the present invention is excellent in impact absorption during peeling according to its structural characteristics, and simultaneously provides peel stability and secular stability with less increase in peel strength .

Hereinafter, each layer constituting the release film of the present invention will be described.

1. Base layer (10)

The substrate layer used in the release film of the present invention can be selected from known paper or polyester as the substrate of conventional silicone release coatings.

In the examples of the present invention, polyester resins such as polyethylene terephthalate, polybutylene terephthalate and polyethylene naphthalate are mainly described, but the present invention is not limited thereto.

The polyester-based resin constituting the base layer is obtained by polycondensing an aromatic dicarboxylic acid and an aliphatic glycol. Examples of the aromatic dicarboxylic acid include terephthalic acid and 2,6-naphthalenedicarboxylic acid. Examples of the aliphatic glycol include Ethylene glycol, diethylene glycol, 1,4-cyclohexanedimethanol, and the like. Representative polyesters include polyethylene terephthalate (PET), polyethylene-2,6-naphthalenedicarboxylate (PEN), and the like.

The polyester may be a copolymer containing a third component. Examples of the dicarboxylic acid component of the copolymer polyester include isophthalic acid, phthalic acid, terephthalic acid, 2,6-naphthalenedicarboxylic acid, adipic acid, sebacic acid, oxycarboxylic acid (such as P-oxybenzoic acid) Examples of the glycol component include ethylene glycol, diethylene glycol, propylene glycol, butanediol, 1,4-cyclohexanedimethanol, neopentyl glycol and the like. These dicarboxylic acid components and glycol components may be used in combination of two or more.

2. The release layer (20)

The present invention forms a multi-layer release layer having a crosslinking density different on the base layer.

At this time, from the high crosslink density of the first release layer formed in the vicinity of the substrate layer, the release layers gradually decrease in thickness.

The release layer of the present invention is formed by a silicone release composition.

More specifically, in the release film of the present invention, the multi-layer release layer is designed such that the cross-link density is gradually increased from the release layer formed by the addition reaction type silicone release composition, while the first release layer has the highest cross- And a plurality of release layers are successively laminated.

At this time, the silicone mold releasing composition is a conventionally known addition reaction type silicone mold releasing composition, and contains an addition reaction type silicone resin as a main component, and the crosslinking agent or the catalyst may be included in the addition reaction type silicone resin. Further, it may further include an addition reaction inhibitor, a peel adjustment agent, an adhesion improver, a photosensitizer, and the like.

When the silicone resin is an addition reaction type silicone resin, it may be either a solvent type or an emulsion type, but a solvent type releasing agent is suitable in terms of quality and ease of handling.

The addition reaction type silicone resin is not particularly limited and may be selected from those used as a releasing agent usually composed of a thermosetting part reaction type silicone resin. As a preferable example thereof, a reaction type silicone resin (Si-R, And R is an alkenyl group) can be used as the polyorganosiloxane.

Preferable examples of the polyorganosiloxane having an alkenyl group include a polydimethylsiloxane having a vinyl group as a functional group or a polydimethylsiloxane having a hexenyl group as a functional group, or a mixture thereof.

(Si-H) having at least two hydrogen atoms bonded to a silicon atom in one molecule is added to the addition reaction type silicone mold releasing composition in order to realize the release layer having different crosslinking densities of the present invention. A crosslinking agent may be further added to increase the crosslinking density.

Specific examples of the hydrogel polyorganosiloxane (Si-H) crosslinking agent include end-blocked dimethylsiloxane / methylhydrogen-siloxane copolymer, dimethylsiloxane / methylhydrogensiloxane copolymer end-capped with trimethylsiloxy groups, Trimethylsiloxy group and poly (methylhydrogen-siloxane) end-blocked with poly (hydrogensilquioxane).

Generally, depending on the composition ratio of the Si-H group of the hydrogel polyorganosiloxane involved in the crosslinking reaction and the Si-R group of the reactor (Si-R, R is an alkenyl group) of the addition reaction type silicone resin, It directly affects the crosslinking density. At this time, as the amount of Si-H increases, the cross-linking reaction active sites increase and the cross-link density of the release layer increases.

As the embodiment for forming the release layer of the present invention, the composition ratio of the Si-H group of the hydrolytic polysiloxane and the Si-R group of the alkenyl polysiloxane is set to 1.0? Si-H / Si- R is an alkenyl group). However, in order to form a multi-layered release layer having a different cross-linking density, the composition ratio of Si-H / Si-R varies depending on the release layer having a desired cross-linking density. That is, in order to increase the crosslinking density to form a very hard releasing layer, the silicon releasing layer can be formed by raising the composition ratio of Si-H / Si-R to 2.0 to 12. However, in order to form the releasing layer having different crosslinking densities It is not particularly limited to the composition ratio within the technical idea.

In addition to the above, as a component contained in the silicone mold-releasing composition, a platinum catalyst, a palladium catalyst or a rhodium catalyst may generally be used as a catalyst in order to accelerate the polymerization reaction. It is applied within the accepted range to be used.

Examples of the release-controlling agent include dimethylpolysiloxane and silicone resin.

Further, the addition reaction inhibitor is a component used for the purpose of providing storage stability at room temperature with respect to the silicone resin, specifically, 3,5-dimethyl-1-hexyn-3-ol, 3- Methyl-3-pentene-1-yne, 3,5-dimethyl-3-hexene-1-yne, cyclic tetravinylsiloxane and benzotriazole can be used.

The photosensitizer is not particularly limited, but is preferably selected from those used in usual ultraviolet curable resins. Representative examples thereof include benzoin, benzophenone, acetophenone,? -Hydroxy ketone,? -Amino ketone,? -Diketone, ? -diketone dialkyl acetal, anthraquinone, and thioxanthone, or a mixed form thereof may be used.

Another embodiment for forming a multi-layer release layer having different crosslinking densities in the release film of the present invention is that the addition reaction type silicone release composition described above further contains a solventless silicone release agent having a short chain length.

That is, as a solventless silicone release agent, the solventless alkenylpolysiloxane is shorter in length than the solvent-type alkenylpolysiloxane and has a large number of crosslinking reaction sites, so that the crosslinking density can be increased when it is added to the releasing composition. Thus, by adding an unsaturated-type alkenyl polysiloxane having a short polymer length to the solvent-form silicone mold releasing composition, a rigid release layer can be formed by increasing the crosslinking density.

At this time, a known substance can be used as the solvent-free alkenylpolysiloxane, but in the case of the solvent-type alkenylpolysiloxane, the viscosity is 10,000 to 50,000 mPa * s in a 30% toluene solution, while the solventless alkenylpolysiloxane has a viscosity of 50- 5,000 mPa * s. If the viscosity of the alkenylpolysiloxane without solvent is less than 50 mPa * s, the chain length is too short to cause curing defects. If the viscosity is more than 5,000 mPa * s, the chain length becomes long and is suitable for the purpose of the present invention not.

It is preferable that the solventless alkenyl polysiloxane further contains 0.01 to 2 parts by weight based on 100 parts by weight of the solvent of the addition reaction type silicone mold release composition. If the content of the alkenylpolysiloxane is less than 0.01 part by weight, the effect of increasing the crosslinking density is insufficient. If the content is more than 2 parts by weight, the coating property is not preferable.

As shown in Fig. 1, as a preferred example of the present invention, the release film described in the embodiment includes a first release layer 21; And a second release layer (22) are sequentially laminated, wherein the first release layer (21) versus the second release layer (22) is designed to have a high cross-link density.

The first release layer 21 may further contain a crosslinking agent or a solventless silicone release agent in the addition reaction type silicone release mold composition or may further contain a crosslinking agent and a solventless silicone release agent so that the ratio The crosslinking density can be increased. Accordingly, the multi-layer release layer sequentially laminated on the first release layer of the present invention may be variously changed by technical means for controlling the cross-link density.

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

The present invention is intended to more specifically illustrate the present invention, and the scope of the present invention is not limited by these examples.

< Example  1> Production of laminated release film

On the one surface of the polyester base layer 10, a mold releasing solution consisting of the silicone mold release composition (1) shown in the following Table 1 was applied in a thickness of 15 탆 to form the first release layer 21. At this time, a crosslinking density of the first release layer 21 was increased by adding a silicone-free silicone release agent having a small silicone polymer molecular weight. After coating, the coating was heat-treated for 30 seconds in a hot-air dryer at 130 캜. At this time, the following silicone mold release composition (1) increased the crosslinking density of the first release layer by increasing the content of the silicone crosslinking agent.

After the heat-treated releasing film was stored at 50 캜 for 24 hours, a mold releasing solution consisting of the silicone releasing composition (2) shown in Table 2 was applied in a thickness of 15 탆 to form a second releasing layer 22. After the application, it was heat treated in a hot air drier at 130 캜 for 30 seconds.

The heat-treated releasing film was stored at 50 DEG C for 24 hours to prepare a releasing film (1) in which releasing layers (20) having different crosslinking densities were sequentially laminated.

< Example  2> Production of laminated release film

Except that the first release layer 21 was formed by coating a release coating solution composed of the silicone release composition 3 of Table 3 below instead of the silicone release composition 1 in Example 1, To prepare a release film in which release layers having different crosslinking densities were successively laminated.

< Example  3> Production of laminated release film

Except that the first release layer 21 was formed by coating a release coating solution composed of the silicone mold release composition 4 of Table 4 below in place of the silicone release composition 1 in Example 1, To prepare a release film in which release layers having different crosslinking densities were successively laminated.

The mold releasing solution composed of the silicone mold release composition (1) used in Example 1 was applied once to the surface of the polyester base layer 10 once to a thickness of 15 탆 and then heat treated for 30 seconds in a hot air drier at 130 캜, A single-layer release film was produced.

< Comparative Example  2>

A mold releasing solution consisting of the silicone mold release composition (2) used in Example 1 was applied once to the surface of the polyester base layer 10 once to a thickness of 15 탆 and then heat treated for 30 seconds in a hot air drier at 130 캜, A single-layer release film was produced.

< Comparative Example  3>

The mold releasing solution composed of the silicone mold releasing composition (3) used in Example 2 was applied once to the surface of the polyester base layer 10 once to a thickness of 15 탆 and then heat-treated for 30 seconds in a hot air dryer at 130 캜, A single-layer release film was produced.

< Comparative Example  4>

The mold releasing solution consisting of the silicone mold release composition (2) used in Example 1 was applied once to the surface of the polyester base layer 10 once to a thickness of 15 탆 and then heat treated for 30 seconds in a hot air drier at 130 캜, 1 mold releasing layer 21 was formed on the first release layer 21. The mold releasing solution consisting of the silicone mold releasing composition 1 used in Example 1 was applied once to the first release layer 21 in a thickness of 15 탆, Treated for 30 seconds in a hot-air drier to form a second release layer 22, thereby producing a release film in which release layers having different cross-linking densities were successively laminated.

<Experimental Example 1> Measurement of peeling force

A standard pressure-sensitive adhesive tape (TESA 7475) was attached to the outermost release layer coating surface of the release films prepared in Examples 1 to 3 and Comparative Examples 1 to 3, and the pressure-sensitive adhesive tape was reciprocated twice with a rubber roller of 2 kg in weight, A measurement sample was prepared.

The results of measurement according to the peel strength measurement conditions in Table 5 are shown in Table 6 below.

From the results shown in Table 6, the laminated release films of Examples 1 to 3 in which two release layers having different cross-linking densities were formed on the base layer did not generate any gibberish sound at the time of peeling after 14 days of peeling force measurement time.

On the other hand, in the case of the release film of the single layer, in the release films of Comparative Examples 1 and 3 in which a release layer of a single layer was formed by the silicone release composition having a high crosslinking density, a gummy sound was observed in peeling after 7 days from the peeling force measurement time .

From the above results, it can be seen that when a release layer having a high crosslinking density is formed, a sound is generated during peeling and stable peeling is difficult, but the release film of the laminate of the present invention has such a problem that the release layer having a low cross- Respectively.

< Experimental Example  2> Measurement over time

From the results of Table 5 obtained in Experimental Example 1, the elapsed time rate of change was calculated by the following equation (1).

Equation 1

(X-initial value) / initial value (X = peeling force after 1 day, after 7 days, and after 14 days)

FIG . 3 shows the result of comparing the rate of change with time with respect to the release film of Example 2 of the present invention, and FIG. 4 The result of comparing the change rate with time with respect to the release film of Example 3 of the present invention is shown.

From the results shown in Figs. 2 to 4, it can be seen that the release film of the laminate prepared in Examples 1 to 3 slightly increased in peel strength with time compared with that of the release film of Comparative Example 1 in which the release layer having a high cross- , And a significantly lower rate of change in peel strength over time was observed as compared with Comparative Example 2 formed with a single layer structure of a release layer having a low cross-linking density.

3, the release film of the laminate prepared in Example 2 was compared with those of Comparative Example 2 and Comparative Example 3, and it was found that the change in peel strength with elapse of time was somewhat less than that of Comparative Example 3 in which the release layer having a high cross- , But a lower rate of peel strength over time than Comparative Example 2 was observed.

From the results of the peeling force measurement and the results of the rate of change with time, it can be seen that the release film of the present invention is obtained by sequentially laminating the release layers 20 having different cross-linking densities on the base layer 10, Compared with the release films of Comparative Examples 1 and 3 comprising the release layer of the present invention.

Further, it was confirmed that the peel strength of the release film of Comparative Example 2, which was composed of a release layer of a single layer having a low cross-linking density, was small compared with the release film.

On the other hand, in the case of the release film of Comparative Example 4, when the crosslinking density of the first release layer is lower than that of the second release layer, a zigzag sound is generated, so that in the case of the release film produced according to the crosslink density gradient specified in the present invention Was confirmed.

INDUSTRIAL APPLICABILITY As described above, the present invention provides a release film in which a plurality of release layers having different crosslinking densities are formed on a base layer.

In particular, the release film of the present invention has a low crosslinking density at the outermost side of the release film and a release layer of a soft film, so that the release of shock is smooth during peeling so that the peeling stability is provided and the cross- By forming the release layer of the high and hard film, it is possible to prevent an increase in the peeling force with time due to the physical penetration of the pressure-sensitive adhesive, so that the temporal stability can be satisfied at the same time.

While the invention has been shown and described with reference to certain exemplary embodiments thereof, it will be understood by those skilled in the art that various changes and modifications may be made without departing from the spirit and scope of the invention as defined by the appended claims.

1: release film
10: substrate layer
20: Release layer having different crosslinking density
21: first release layer
22: second release layer

Claims (10)

A base layer;
A first release layer formed on at least one surface of the substrate layer; And
And a release layer formed on the first release layer in sequence according to a cross-link density gradient, the release layer having different cross-linking densities. The method of claim 1, wherein the cross-linking density gradient is gradually lowered from a cross-linking density of the first release layer to a multi-layer release layer that is sequentially stacked on the first release layer. A release film in which release layers are laminated. The method of claim 1, wherein the first release layer and the multi-layer release layer are formed of a release layer having controlled cross-linking density by an addition reaction type silicone mold release composition, wherein the first release layer has the highest cross- Wherein the releasing layer has a different crosslinking density. The method according to claim 3, wherein the multi-layer release layer
The crosslinking density was controlled according to the composition ratio of the Si-H reactor of the hydrotable polysiloxane and the Si-R reactor of the polyorganosilox having the alkenyl group in the addition reaction type silicone mold release composition according to 1.0? Si-H / Si-R? Characterized in that the releasing layer having different crosslinking densities is laminated. 4. The method according to claim 3, wherein the addition reaction type silicone mold release composition further contains a hydrogel polyorganosiloxane (Si-H) crosslinking agent having at least two hydrogen atoms bonded to silicon atoms in one molecule, Wherein the releasing layer has a different crosslinking density. 6. The composition of claim 5, wherein the hydrogel polyorganosiloxane crosslinker is a dimethylsiloxane / methylhydrogen-siloxane copolymer end-capped with a dimethylhydrogensiloxy group, a dimethylsiloxane / methylhydrogen- (Methylhydrogen-siloxane) end-capped with a siloxane copolymer, a trimethylsiloxy group, and a poly (hydrogensilquioxane). Release film. 6. The method according to claim 5, wherein the cross-linking density is controlled in the range of 2.0? Si-H / Si-R? 12.0 in a Si-R reactor having a polyorganosiloxane having an Si-H reactor and an alkenyl group of a hydrotreater polysiloxane Characterized in that the releasing layer having different crosslinking densities is laminated. The release film according to claim 3, wherein the addition reaction type silicone mold release composition further contains a solventless silicone release agent to increase the crosslinking density. The release film according to claim 8, wherein the solventless silicone release agent satisfies a viscosity of 50 to 5000 mPa * s in a 30% toluene solution. The release film according to claim 8, wherein the solventless silicone release agent is contained in an amount of 0.01 to 2 parts by weight based on 100 parts by weight of the solvent of the addition reaction type silicone release agent composition.

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