CN114667329A

CN114667329A - Release film with ultralow peel strength

Info

Publication number: CN114667329A
Application number: CN202080078371.5A
Authority: CN
Inventors: 张民怄; 尹宗郁
Original assignee: Toray Advanced Materials Korea Inc
Current assignee: Toray Advanced Materials Korea Inc
Priority date: 2019-11-11
Filing date: 2020-01-06
Publication date: 2022-06-24
Anticipated expiration: 2040-01-06
Also published as: CN114667329B; WO2021095990A1; CN114667329B9; KR20210056593A; KR102306997B1

Abstract

The present invention relates to an ultra-low peel strength release film, and more particularly to an ultra-low peel strength release film that: by using a polyester binder resin and an oxazoline group-containing resin which are low in reactivity with polysiloxane, good adhesion to a substrate and solvent resistance are achieved, and the change with time at high temperature of the release region is minimized.

Description

Release film with ultralow peel strength

Technical Field

The present invention relates to such ultra-low peel strength release films: has excellent characteristics of adhesion to a substrate and solvent resistance, even when a release region of high thickness is formed to achieve an ultra-low peel strength, the change of the ultra-low peel strength in the release region with time at high temperature is minimized.

Background

In the field of release films that are typically used to protect adhesive layers, there is a need for release films that are very resistant to the different solvents used in adhesives.

For this reason, when a general method for improving the cross-link density by improving the cross-link density of polysiloxane by using a platinum catalyst or a hydrolyzed silane oligomer having a reactive group is used, polysiloxane takes part in the reaction of additives to change the release force of a release film or reduce the residual adhesion.

Further, although another method is to add an adhesive such as polyurethane, polyester, acrylic, etc. to the coating liquid to improve the adhesion to the substrate as described in korean patent laid-open No. 10-2017-0099980, it is necessary to exclude a functional group that may act as a catalyst poison in configuring the release layer, thereby causing some loss of physical release characteristics in this case.

In particular, although the release film market continues to require an ultra-low peel strength release film that achieves a very small peel force, and as described in published korean patent No. 10-2017 0067067, an ultra-low peel strength is achieved by increasing the thickness of a release layer or using a substance that requires a very small peel force, with the result that the peel force at high temperature varies due to changes over time.

Therefore, there is a strong need to develop a release film: which achieves good solvent resistance and adhesion to the substrate, and little change in ultra-low peel strength over time.

Disclosure of Invention

Technical problem

The present invention aims to solve the aforementioned problems and solve the conventional needs by providing a release film having an ultra-low peel strength with good adhesion to a substrate and solvent resistance.

Another object of the present invention is to provide a release film of ultra-low peel strength, thereby minimizing a change of a release region with time at a high temperature even when the release region is formed to have a high thickness to achieve ultra-low peel strength.

The foregoing and other objects and advantages of the invention will be apparent from the following description provided for the purpose of describing preferred embodiments of the invention.

Means for solving the problems

In view of the above description, the present invention provides an ultra-low peel strength release film comprising a substrate and a coating layer positioned on at least one side of the substrate, wherein the coating layer is made of an aqueous release coating solution and comprises an anchoring region and a release region.

As used herein, the aqueous release coating solution may comprise a vinyl polysiloxane, a hydrogen polysiloxane, a polyester resin, a silicone oil, and a silicone oil

An oxazoline-based resin, a platinum catalyst, a surfactant, and a solvent.

Preferably, the anchoring region may be formed of a polyester resin and a polyester resin

Resin formation of the oxazoline group.

Preferably, the anchor region may include 0.1 to 10 parts by weight of a polyester resin based on 100 parts by weight of the polyester resin

Resins of oxazoline groups.

Preferably, the release region may be formed of a vinyl polysiloxane and a hydrogen polysiloxane.

Preferably, the release region may include 110 to 200 parts by weight of the hydrogenpolysiloxane based on 100 parts by weight of the vinyl polysiloxane.

Preferably, the solvent may comprise 80 to 99 wt% water and 1 to 20 wt% ethylene glycol.

Preferably, the aqueous release coating liquid may further include an antistatic agent.

Preferably, the dry thickness of the coating layer may be 0.01 μm to 2.0 μm.

More preferably, the dry thickness of the coating layer may be 0.5 μm to 1.0 μm.

Preferably, the release film of ultra low peel strength may have a peel force of 15 gf/inch or less after aging at 60 ℃ and 90% RH for one day at high temperature and one day at room temperature, respectively.

Preferably, the release film of ultra low peel strength may have a difference in peel force of less than 10% after aging at 60 ℃ and 90% RH for one day at high temperature and one day at room temperature.

Preferably, the residual adhesion of the ultra-low peel strength release film may be 90% or more.

Preferably, after rubbing the coating of the ultra-low peel strength release film back and forth three times with a cleaning cloth soaked in isopropyl alcohol (IPA), the coating of the ultra-low peel strength release film cannot be peeled.

Effects of the invention

The release film of the present invention is effective for achieving good adhesion to a substrate and solvent resistance.

Even when a release region of high thickness is formed to achieve an ultra-low peel strength, the change of the release region with time at high temperature can be minimized.

It should be noted that the effect of the present invention is not limited to the aforementioned effect, and other effects not mentioned above should be apparent to those skilled in the art.

Drawings

Fig. 1 shows a schematic cross section of an ultra-low peel strength release film according to one embodiment of the present invention; and

fig. 2 shows a schematic cross section of an ultra-low peel strength release film according to another embodiment of the present invention.

Best mode for carrying out the invention

Hereinafter, the present invention will be described in more detail with reference to embodiments of the present invention and the accompanying drawings. It should be apparent to those skilled in the art that these embodiments are provided only to more specifically describe the present invention, and the scope of the present invention should not be limited by these embodiments.

Unless defined otherwise, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs. In case of conflict, the present specification, including definitions, will control. In addition, although methods and materials similar or equivalent to those described herein can be used in the practice or testing of the present invention, suitable methods and materials are set forth in the specification.

As used in this specification, the terms "comprises," "comprising," "includes," "including," "contains," "containing," "characterized by," "having," "has" or other variations thereof are intended to cover non-exclusive inclusions. For example, a process, method, article, or apparatus that comprises a list of elements is not limited to only those elements but may include other elements not expressly listed or included in the process, method, article, or apparatus. Further, "or" should not mean an exclusive "or" but rather a comprehensive "or" unless expressly stated otherwise.

First, an ultra-low peel strength release film according to an embodiment of the present invention will be described in detail with reference to schematic cross sections of fig. 1 and 2 showing the ultra-low peel strength release film according to a preferred embodiment and other embodiments of the present invention, respectively.

Referring to fig. 1, an ultra-low peel strength release film 100 according to an embodiment of the present invention is a release film: which includes a substrate 10 and a coating layer 20 positioned on at least one side of the substrate, the coating layer 20 being formed by applying an aqueous coating liquid and having a structure in which an anchor region 21 and a release region 22 of the coating layer 20 alternate left and right.

In addition, referring to fig. 2, the ultra-low peel strength release film 100 according to another embodiment of the present invention may have a structure in which the anchor region 21 and the release region 22 of the coating layer 20 contact each other at the top and bottom thereof.

Although the anchor region 21 is clearly physically separated from the release region 22 in fig. 1 and 2, this is merely for convenience of illustration, and shows a structure that can be formed by coating a coating layer at one time. Further, when the boundary between the anchor region 21 and the release region 22 may not be clear from each other, the two states of fig. 1 and 2 may be mixed, and it is probable that the state of fig. 2 is probabilistically not the state of fig. 1.

Although there is no limitation to the substrate 10, it is preferable to use a polyethylene terephthalate film having high performance in terms of heat resistance, chemical resistance, mechanical strength, and economic efficiency. In particular, it is preferable that the film is 10 μm to 200 μm in thickness.

In one embodiment, the aqueous release coating solution constituting the coating layer 20 comprises a vinyl polysiloxane, a hydrogen polysiloxane, a polyester resin, a silicone oil, and a silicone oil

An oxazoline-based resin, a platinum catalyst, a surfactant, and a solvent, and the coating layer is formed by applying a liquid on one side or both sides of the substrate 10 and then thermally curing the coating layer.

In one embodiment, the anchor region 21 is formed of a polyester resin as a binder resin and a hardener containing polyester resin as a hardener in an aqueous release coating solution

Resin formation of the oxazoline group.

In addition, for the polyester resin forming the anchoring area 21 and the polyester resin composition

The oxazoline-group resin is not particularly limited and allows the use of any commercial product generally used in industry.

In the present invention, since the polyester resin forming the anchor region 21 is used and the polyester resin

The oxazoline group-based resin can minimize the reaction with polysiloxane (a component of the coating liquid), and thus can provide a release film having sufficient adhesion to a substrate and solvent resistance. Further, even when a high thickness release region is formed to achieve an ultra-low peel strength, the anchor region 21 helps to minimize the change of the release region with time at high temperature. In other words, since the polyester resin is used and the polyester resin composition contains

The oxazoline group-based resin first obtains crosslinking of carboxylic acid in the polyester resin, and therefore, a desired solvent resistance can be ensured even if the crosslinking density of silicone is not high, and for this reason, the silicone release region is kept soft rather than hard to achieve an ultra-low peel strength and a good high solvent resistance.

In one embodiment, it is preferable to include 0.1 to 10 parts by weight of a polyester resin based on 100 parts by weight of the polyester resin

Resins of oxazoline groups. Less than 0.1 part by weight of a composition comprising

Oxazoline group containing resins have reduced solvent resistance, but more than 10 parts by weight

The oxazoline group resin inhibits the curing of organic silicon, so that the release property of the film is poor.

In one embodiment, the release region 22 is formed of a vinyl polysiloxane and a hydrogen polysiloxane contained in an aqueous release coating liquid.

The vinyl silicone emulsion and the hydrogen silicone emulsion in the aqueous release coating liquid are not particularly limited, and may be any silicone emulsion generally used in industry.

In one embodiment, it is preferable to include 110 parts by weight to 200 parts by weight of the hydrogenpolysiloxane based on 100 parts by weight of the vinylpolysiloxane. When the hydrogenpolysiloxane is less than 110 parts by weight, high silicone transfer is caused, and when the hydrogenpolysiloxane is more than 200 parts by weight, poor stability in terms of change with time at high temperature is caused.

As described above, the ultra-low peel strength release film according to the present invention ensures good curing properties of silicone even at coating condition temperatures of 130 ℃ to 150 ℃ by controlling the ratio of vinyl polysiloxane to hydrogen polysiloxane.

Further, there is no particular limitation on the platinum catalyst, which may be a commercial product generally used in industry.

In one embodiment, for the solvent in the aqueous release coating liquid, it is preferable to use 80 wt% of water based on the total weight of the coating liquid, and it is preferable to use a solvent produced by mixing 80 to 99 wt% of water with 1 to 20 wt% of ethylene glycol (co-solvent) to ensure the stability of the coating liquid. As described above, the coating according to an embodiment of the present invention may provide a release film: the release film can achieve the same level of appearance and adhesion to a substrate as an organic solvent when 80 wt% or more of water is used as a solvent. Therefore, a small amount of VOC gas is discharged, which means an environmentally friendly material, and the release film of the present invention can be suitably used in various fields such as food and material industries in the electronic and electrical fields.

In one embodiment, an antistatic layer may be further disposed on the coating layer 20 for antistatic characteristics, or the aqueous release coating liquid forming the coating layer 20 may further include a conductive polymer resin as an antistatic agent. The conductive polymer resin is preferably an aqueous dispersion containing poly-anions and polythiophene or an aqueous dispersion containing poly-anions and polythiophene derivatives. The polyanion is an acid polymer such as polymeric carboxylic acid, polymeric sulfonic acid, polyvinylsulfonic acid, and the like. Exemplary polymeric carboxylic acids include polyacrylic acid, polymethacrylic acid, and polymaleic acid, and exemplary polymeric sulfonic acids include polystyrene sulfonic acid, but are not limited thereto. In an embodiment of the present invention, an aqueous solution of conductive polymer PEDOT is used as the conductive polymer resin.

In this case, the conductive polymer resin can realize stable antistatic properties by using an aqueous dispersion having an average particle diameter of 10nm to 90 nm. The conductive polymer resin having an average particle diameter of more than 90nm is not uniformly distributed on the coating layer to cause a great deviation in surface resistance, and the desired antistatic property is not well achieved; the conductive polymer resin having an average particle diameter of less than 10nm has a small molecular weight, thereby facilitating molecules separated from each other by a longer distance than a certain distance, so that the antistatic property cannot be realized; and a smaller average particle size results in lower antistatic properties when in-line stretching is performed.

Further, the aqueous release coating liquid forming the coating layer 20 is thermally cured at a drying temperature of 130 to 280 ℃ to form a coating layer of good appearance, and more preferably, the effect becomes even more remarkable in off-line processing at a drying temperature of 130 to 150 ℃.

In one embodiment, the dry coating thickness of the coating 20 is preferably 0.01 μm to 2.0 μm. The coating thickness of the coating layer less than 0.01 d results in insignificant effect of lowering the peeling force to increase the peeling force at low speed, while the coating thickness of the coating layer more than 2.0 d is too high to cause problems in high-speed productivity.

The dry thickness of the coating is more preferably 0.5 μm to 1.0. mu.m. In the case where the dry coating thickness of the coating layer is less than 0.5 μm, it is difficult to achieve ultra-low peel strength, while the dry coating thickness of the coating layer is more than 1.0 μm, resulting in a blocking problem.

The method for applying the coating liquid forming the coating layer 20 is not limited to a specific method, and applicable methods include bar coating, gravure coating, comma coating, die coating, or the like. An aqueous release coating solution applied in a liquid phase was thermally cured at about 150 ℃ for a time of about 30 seconds in a warm air chamber to obtain a cured release region and an anchor region.

In one embodiment, the release film aged at 60 ℃ and 90% RH for one day at high temperature and ultra low peel strength after aging for one day at room temperature, respectively, preferably has a peel force of not more than 15 gf/inch.

In one embodiment, the release film with ultra low peel strength after one day of aging at 60 ℃ and 90% RH at elevated temperature and one day of aging at room temperature, respectively, has a peel force difference of less than 10%.

In one embodiment, the residual adhesion of the ultra-low peel strength release film is preferably 90% or more.

In one embodiment, after rubbing an ultra-low peel strength release film back and forth three times with a cleaning cloth soaked in isopropyl alcohol (IPA), the ultra-low peel strength release film preferably shows no coating peeling.

The configuration and subsequent effects of the present invention will be described in detail below by way of embodiments and comparative examples. It should be noted that those schemes are intended to describe the present invention more specifically, and the scope of the present invention should not be limited to those embodiments.

[ embodiment ]

[ embodiment 1]

1. Base film

As the substrate film, a 50 μm-thick polyethylene terephthalate film (product: XD500) produced by TORAY ADVANCED MATERIALS was used.

2. Coating layer

Using a bar coater to apply an aqueous release coating solution on a base film, the aqueous release coating solution comprising: 5 parts by weight of a silicone emulsion resin composed of a vinyl silicone emulsion and a hydrogen silicone emulsion and containing 100 parts by weight of vinyl siloxane and 140 parts by weight of hydrogen silicone, manufactured by Dow Chemical, product: SYL-OFF 7920; 0.5 parts by weight of a platinum catalyst, manufactured by Dow Chemical, product: SYL-OFF 7924; 10 parts by weight of a polyester binder resin produced by BASEKOREA, product: EW-210S; 0.1 part by weight of a solvent containing

Trees of oxazoline groupsFat, produced by NIPPON SHOKUBII, product: WS-700; 0.1 part by weight of a surfactant produced by BYK, product: BYK 348; 95 parts by weight of water; and 4 parts by weight of ethylene glycol, which was thermally cured at 140 ℃ for 30 seconds in a hot air chamber to form a release film having a coating layer with a thickness of 0.5 μm.

[ embodiment 2]

The same procedure as in embodiment 1 was performed to produce a release film except that an aqueous release coating liquid containing 20 parts by weight of silicone emulsion resin and 2 parts by weight of platinum catalyst was applied to achieve a dry thickness of 1 μm.

[ embodiment 3]

The same procedure as in embodiment 1 was carried out to produce a release film except that an aqueous release coating solution comprising 20 parts by weight of an aqueous conductive polymer PEDOT solution (product: Clevious PT) produced by Heraeus was applied.

Comparative example 1

The same process as in embodiment 1 was performed to produce a release film, except that an aqueous release coating solution comprising: 5 parts by weight of a silicone emulsion resin composed of a vinyl siloxane emulsion and a hydrogen polysiloxane emulsion, manufactured by Dow Chemical, product: SYL-OFF 7920; 0.5 parts by weight of a platinum catalyst, manufactured by Dow Chemical, product: SYL-OFF 7924; 0.1 part by weight of a surfactant produced by BYK, product: BYK 348; 95 parts by weight of water and 4 parts by weight of ethylene glycol.

Comparative example 2

The same process as in comparative example 1 was performed to produce a release film, except that the aqueous release coating solution further contained 5 parts by weight of a polyester resin.

Comparative example 3

The same procedure as in comparative example 1 was conducted to produce a release film, except that the aqueous release coating liquid further contained 1 part by weight of a silane coupling agent (product: Z-6043) produced by Dow Chemical.

Comparative example 4

The same procedure as in comparative example 1 was carried out to produce a release film, except that the aqueous release coating solution further contained 10 parts by weight of a polyurethane binder (product: UREARNO W321) produced by arakaa.

Comparative example 5

The same process as comparative example 1 was carried out to produce a release film except that the dry thickness was 1 μm.

The release films according to the foregoing embodiments 1 to 3 and comparative examples 1 to 5 were used to measure their physical properties through the following exemplary experiments, and the results are shown in the following table 1.

[ exemplary experiment ]

1. Solvent resistance

The release film was rubbed back and forth three times with a thin cleaning cloth with a very rough surface soaked in isopropyl alcohol (IPA) to check whether its coating was peeled off, and its evaluation was based on the following criteria:

o: good solvent resistance, no peeling of the coating;

and (delta): poor solvent resistance, partial failure of the coating; and

x: without solvent resistance, most of the coating was damaged;

2. appearance of the product

The following criteria were used to evaluate a4 size release coated film based on the presence of spotting and shrinkage:

o: a clean appearance without shrinkage and spotting;

and (delta): there are shrinkage and spots in some parts of the film, the number in the a4 size being no more than 10; and

x: poor appearance due to poor wettability.

3. Adhesion to substrates

The release coating was rubbed back and forth ten times by hand as a rubbing test to evaluate the release coating according to the level of peeling:

o: the release coating is not peeled off;

and (delta): partially stripping the release coating; and

x: most of the release coating peels off.

4. Adhesion to substrates at elevated temperatures

The produced release film was aged in a thermo-hygrostat (thermo-hygrostat) chamber at 60 ℃ and 90% RH for one day, and then the release coating was rubbed back and forth ten times by hand to evaluate it according to its release level with the following criteria:

o: the release coating is not peeled off;

and (delta): partially stripping the release coating; and

x: most of the release coating peels off.

5. Peel force at room temperature

A standard adhesive tape TESA7475 generally used in the industry was used to evaluate the peeling force of the release film according to the embodiment and the comparative example.

First, a 2kg roller was used to adhere an adhesive tape to the release coating surface in the release area, and the peel force when the film was peeled was measured after aging it for one day at room temperature; and the peel force (in gf/inch) when it was peeled at 180 ° and a peeling speed of 0.3mpm was measured using an instrument AR-1000 available from chemistrcontent.

6. Peel force at high temperature

The produced release film was aged in a constant temperature and humidity chamber at 60 ℃ and 90% RH for one day, and then subjected to a friction test, after which the release force of the produced release film was measured in the same manner as in the above exemplary experiment 5.

7. Difference in peeling force

The following equation 1 was used to calculate the peel force difference between the peel force at room temperature and the peel force at high temperature measured in the above exemplary experiments 5 and 6.

(equation 1)

Peel force difference (%) (peel force at high temperature-peel force at room temperature)/peel force at high temperature 100 (%)

8. Measured residual adhesion

After the release coating sample for measurement was held at 25 ℃ and 65% RH for 24 hours, a standard adhesive tape (Nitto 31B) was adhered to the release coating surface, and the sample was at 20g/cm at room temperature²Is pressed for 24 hours under the load of (1). Collecting adhesion to release coating without any contaminationThe adhesive tape on the surface of the layer was then adhered to a flat and clean PET film by rolling a 2kg adhesive tape roller (astm d-1000-55T) back and forth once to press it. The peel force was measured as follows to calculate the residual adhesion with equation 2:

the measuring instrument is as follows: chem- [0149] Instrument AR-1000; and

the measuring method comprises the following steps: at a peel angle of 180 deg., at a peel speed of 0.3 m/min.

[ equation 2]

Residual adhesion (%) [ peeling force of adhesive tape adhered to and peeled from the coating surface/peeling force of adhesive tape not adhered to the coating surface ] x 100 (%)

9. Antistatic Properties

After the sample was placed in an environment of 23 ℃ and 50% RH, the surface resistance was measured using an antistatic tester (model: MCP-T600) available from Mitsubishi to measure the surface resistance based on the specification JIS K7194.

[ Table 1]

As seen in table 1, the release film according to embodiment 1 of the present invention achieved good solvent resistance, adhesion to a substrate at both room temperature and high temperature, and a difference of 2.4% between the peeling force at room temperature and high temperature, thereby implying good change with time under conditions of high temperature and high humidity. Further, although the dry thickness of the coating layer is 1 μm to achieve an ultra-low peel strength, the release film according to embodiment 2 achieves good stability over time under conditions of high temperature and high humidity. In particular, the release film including the antistatic agent according to embodiment 3 realizes good surface resistance and other good physical properties.

Meanwhile, it is seen that the general release film in comparative example 1 exhibits poor solvent resistance, poor adhesion to a substrate, and poor adhesion to a substrate at high temperature, and also has significantly low stability over time under high temperature and high humidity conditions since the difference in peeling force between room temperature and high temperature is 50% or more.

See that by using only does not

The oxazoline group-based polyester binder resin, the release film in comparative example 2, exhibited low solvent resistance and poor adhesion to the substrate at high temperature.

Further, although the silane coupling agent is added as a method generally used to improve adhesion to a substrate and solvent resistance, it is seen that the release film in comparative example 3 exhibits significantly lower physical properties than the release films according to embodiments 1 to 3 of the present invention.

Furthermore, it is seen that the release film in comparative example 4 exhibits significantly lower residual adhesion due to insufficient silicone curing caused by catalyst poisons when a polyurethane binder is used.

Further, although the coating layer was made thicker only to achieve an ultra-low peel strength, it was seen that the release film in comparative example 5 exhibited poor adhesion to the substrate at high temperature and significantly low solvent resistance.

As described above, the release film according to an embodiment of the present invention basically exhibits good solvent resistance and good adhesion to a substrate as well as good stability over time at high temperature to cause less change over time under conditions of high temperature and high humidity of 60 ℃ and 90% RH, and thus easily realizes ultra-low peel strength.

Further, when merely increasing the coating thickness to achieve an ultra-low peel strength results in insufficient adhesion between the thick coating layer and the substrate to promote an increase in peel force under high-temperature and high-humidity conditions to cause a potential process accident, although the dried coating layer is made thicker to achieve an ultra-low peel strength, it is seen that the release film according to one embodiment of the present invention achieves good stability over time under high-temperature and high-humidity conditions.

Further, the release film according to an embodiment of the present invention achieves the same level of appearance and adhesion to a substrate as an organic solvent when 80 wt% or more of water is used as a solvent, so that a small amount of VOC gas can be discharged, which means an environmentally friendly material, and the release film of the present invention can be applied to various fields including, for example, food industry and material industry in electronics and electricity, and antistatic properties are desirable to solve the problem of dust or contamination that may occur in the process.

Although some examples selected from various embodiments performed by the inventors of the present invention have been described in the present specification, it should be noted that the technical idea of the present invention is not limited thereto or thereby, and it can be modified and implemented in various forms by those skilled in the art.

Claims

1. An ultra-low peel strength release film comprising a substrate and a coating positioned on at least one side of the substrate, wherein the coating is made from an aqueous release coating solution and comprises:

an anchoring region; and

and a release area.

2. The ultra low peel strength release film according to claim 1, wherein the aqueous release coating solution comprises a vinyl polysiloxane, a hydrogen polysiloxane, a polyester resin, a silicone-containing polymer, and a silicone-containing polymer

An oxazoline-based resin, a platinum catalyst, a surfactant, and a solvent.

3. The ultra-low peel strength release film according to claim 1, wherein the anchoring region is formed by the polyester resin and the polyester-containing resin

Oxazoline group resins.

4. The ultra-low peel strength release film according to claim 3, which is based on 100 parts by weight of the polyester treeThe fat comprises 0.1 to 10 parts by weight of the said fat

Resins of oxazoline groups.

5. The ultra-low peel strength release film according to claim 1, wherein the release region is formed of the vinyl polysiloxane and the hydrogen polysiloxane.

6. The ultra-low peel strength release film according to claim 5, comprising 110 to 200 parts by weight of the hydrogenpolysiloxane based on 100 parts by weight of the vinyl polysiloxane.

7. The ultra-low peel strength release film according to claim 2, wherein the solvent comprises:

80 to 99 wt% water; and

1 to 20% by weight of ethylene glycol.

8. The ultra-low peel strength release film according to claim 2, wherein the aqueous release coating liquid further comprises an antistatic agent.

9. The ultra-low peel strength release film according to claim 1, wherein the dry thickness of the coating layer is 0.01 μ ι η to 2.0 μ ι η.

10. The ultra low peel strength release film according to claim 9, wherein the dry thickness of the coating layer is 0.5 μ ι η to 1.0 μ ι η.

11. The ultra low peel strength release film according to any one of claims 1 to 10, wherein the release force of the ultra low peel strength release film is not more than 15 gf/inch after aging at 60 ℃ and 90% RH for one day at high temperature and one day at room temperature, respectively.

12. The ultra low peel strength release film according to claim 11, wherein the difference in peel force is less than 10% after one day of aging at 60 ℃ and 90% RH at high temperature and one day of aging at room temperature.

13. An ultra-low peel strength release film according to any of claims 1 to 10, wherein the residual adhesion of the ultra-low peel strength release film is at least 90%.

14. The ultra-low peel strength release film according to any one of claims 1 to 10, wherein the coating of ultra-low peel strength release film is not peeled after rubbing the coating back and forth three times with a cleaning cloth soaked in isopropyl alcohol (IPA).