KR20140080659A - Silicone release film and preparing process thereof - Google Patents

Abstract

The present invention relates to a silicone release film for NCF and a method for preparing the same. The silicone release film of the present invention is a release film containing a polyester film and a coating layer which is coated with a silicone release composition on the at least one surface of the polyester film more than once, wherein the film satisfies the following equation 1 to 4: 0.8<= A <=2.0 ---(equation 1), 1.0<= B <=2.0 --- (equation 2), 1000<= C <=10,000 --- (equation 3), and1.5<= D <=3 --- (equation 4). Here, A is the ratio of seven-day fermentation stripping capacity to one-day fermentation stripping capacity, B is the molar ration of Si-H of hydrogen polysiloxane to Si-Alkenyl of Alkenyl polysiloxane which are used in the coating layer, C represents a viscosity (unit: mPa·s) of alkenyl polysiloxane which is used in the coating layer, D represents the ratio (heavy/light stripping) of release film stripping capacity, respectively. When the silicone release film of the present invention is used as a release film of a NCG type adhesion process, excellent adhesion to a substrate and time-dependent stripping stability are provided, and stripping capacity balance can eliminate defects caused by adhesive curling effect when stripping an adhesive layer from a release film, so the conventional problem is addressed.

Description

Technical Field [0001] The present invention relates to a silicon release film,

More particularly, the present invention relates to a silicone release film for NCF, and more particularly to a silicone release film for use in a carrier of a pressure-sensitive adhesive in an adhesive industry, Silicone release film for NCF which does not peel off the coating layer and minimizes the change of physical properties due to less interaction with the pressure-sensitive adhesive and balances the peeling force between the light release and the heavy release film, and a manufacturing method thereof .

In general, a polyester film is excellent in mechanical strength, dimensional stability, flatness, heat resistance, chemical resistance, optical properties, and is excellent in cost performance, and is therefore used as a substrate in various applications. In addition, the polyester release film coated with a silicone component is mainly used for advanced applications requiring a beautiful appearance, high strength, high transparency, and chemical resistance. In particular, a polyester release film coated with a silicone component is used as a polarizer release film, a retardation film release film, and a polarizer protective film as protection for a polarizing plate or a retardation plate-related adhesive, and is used for various types of release applications such as ceramic release and advanced label release.

Particularly, in the IT industry, as a smart phone or a tablet PC is rapidly spreading, the use of a pressure-sensitive adhesive for attaching a thin-film component to the inside of the device is rapidly increasing, and as a result, The use amount of the releasing film to be used is rapidly increasing.

In the case of a releasing film used as a carrier of such a pressure-sensitive adhesive, a releasing film having relatively low peeling force (light peeling) is removed in a state in which the pressure-sensitive adhesive is laminated, and a pressure- And the release film having a relatively high peeling strength (heavy-weight) is removed and used.

The releasing film used for the pressure-sensitive adhesive of the NCF (non-carrier film) type has a problem that the unreacted functional group of the silicone release film and the pressure-sensitive adhesive component slowly react with each other during storage in a state of being kept in a state of being laminated with the pressure- And the peeling force balance (balance) between the light release film and the heavy release film is not matched, so that quality problems such as tearing of the adhesive may occur.

Accordingly, there have been various attempts to provide a release film which is easy to be peeled off easily at the initial stage, does not increase peel strength even after a lapse of time, provides stability over time, For example, in Korean Patent Application No. 2007-0013729 filed by the present applicant, "a polyester base film is produced, and a coating containing a polydimethylsiloxane represented by the general formula (1) and a hydrogensilane represented by the general formula (2) And a curing silicone resin having a degree of polymerization of 50 to 200,000 is added so as to have a total solid concentration of 0.5 to 10% to prepare a coating liquid containing a curable silicone resin, and one surface of the polyester base film , The curable silicone resin-containing coating liquid is coated and then subjected to a curing reaction to form a silicone release Discloses a process for producing a polyester release film for a polarizing plate, characterized in that a polyester film is formed on the polyester base film, and Korean Patent Application No. 2007-0068466 discloses a polyester release film and a method for producing the same, And a silicone release layer coated on at least one surface of the base film with a silicone release liquid, wherein when the silicone release solution is dropped onto the base film, the contact angle (A) of the release solution is 30 degrees & By optimizing the road, the stability of the silicone release layer and the release mold releasing property are uniform, the transfer of the silicone to the transfer layer and the transfer to the pressure-sensitive adhesive layer do not occur, and in particular, the adhesion between the base film and the silicone release layer is improved. Discloses a method which can be usefully used for releasing films or ceramics release and for use in advanced label release applications.

However, the above-mentioned method has not sufficiently solved the problem related to the adhesion of the base material of the release film. The inventors of the present invention have solved this problem and have succeeded in securing stability over time even after laminating the pressure- The present invention has been accomplished on the basis of a study to develop a releasing film suitable for an NCF-type pressure-sensitive adhesive in which the peeling force balance between the intermediate release film and the heavy release film is maintained.

Patent Document 1: Korean Patent Application No. 2007-0013729 Patent Document 2: Korean Patent Application No. 2007-0068466

DISCLOSURE OF THE INVENTION The present invention has been made in view of the above-mentioned prior arts, and it is an object of the present invention to provide an NCF-type pressure-sensitive adhesive which maintains the above-mentioned secular stability and maintains a balance of peeling force between a light release film and a heavy release film To provide a silicone release film suitable for use as a release film.

It is another object of the present invention to provide a method for manufacturing a silicone release film having the above excellent properties more easily.

The present invention may also be directed to accomplishing other objects that can be easily derived by those skilled in the art from the overall description of the present specification, other than the above-described and obvious objects.

In order to accomplish the above object, the present invention provides a silicone release film comprising:

A release film comprising a polyester film and a coating layer applied on at least one side of the polyester film at least once with a silicone release composition,

Wherein the film satisfies the following equations (1) to (4) simultaneously:

0.8? A? 2.0 - (Formula 1)

1.0? B? 2.0 - (Formula 2)

1000? C? 10,000 --- (3)

1.5? D? 3 - (4)

Here, A represents the value of the 7-day aged peel strength / 1-day aged peel strength ratio, and B represents the molar ratio of the Si-H group of the hydrolytic polysiloxane / Si-alkenyl group of the alkenyl polysiloxane used in the coating layer C represents the viscosity (unit: mPa.s) of the alkenyl polysiloxane used in the coating layer, and D represents the value of the releasing film peeling force ratio (heavy peeling / light peeling).

According to another aspect of the present invention, the silicone mold-releasing composition is characterized in that it comprises an alkenyl polysiloxane, a hydro pre-polysiloxane, a surfactant, and a platinum chelate catalyst.

According to another aspect of the present invention, the mold release composition is characterized in that it comprises an organopolysiloxane resin containing a hydroxyl group or an alkenyl group as a peel strength adjusting agent.

According to still another embodiment of the present invention, 0.5 to 5 parts by weight of an organopolysiloxane resin is added to the releasing composition as a releasing force modifier with respect to 100 parts by weight of the alkenyl polysiloxane.

According to another embodiment of the present invention, the peel strength adjusting agent is an organopolysiloxane resin containing a hydroxyl group / alkenyl group in a ratio of 0.1 to 0.5.

According to another embodiment of the present invention, the silicone mold release composition contains 0.5 to 5% by weight of solids.

The silicone release film of the present invention having the above-described structure can be used as a releasing film for an NCF-type adhesive process by controlling the chain length and the curing density of the silicone polymer in the release film coating composition and controlling the peeling force through the additive It is possible to improve defects due to peeling of the pressure-sensitive adhesive, which may be caused when the adhesive layer and the release film are peeled off with a peeling force balance, thereby solving the above-described conventional problems.

Hereinafter, the present invention will be described in more detail by way of preferred embodiments.

A silicone release film for NCF according to a preferred embodiment of the present invention relates to a silicone release film comprising a polyester film and a coating layer applied on at least one side of the polyester film at least once with a silicone release composition, The following formulas 1 to 4 are satisfied at the same time:

0.8? A? 2.0 - (Formula 1)

1.0? B? 2.0 - (Formula 2)

1000? C? 10,000 --- (3)

1.5? D? 3 - (4)

Here, A represents the value of the 7-day aged peel strength / 1-day aged peel strength ratio, and B represents the molar ratio of the Si-H group of the hydrolytic polysiloxane / Si-alkenyl group of the alkenyl polysiloxane used in the coating layer C represents the viscosity (unit: mPa.s) of the alkenyl polysiloxane used in the coating layer, and D represents the value of the releasing film peeling force ratio (heavy peeling / light peeling).

The viscosity described in the present invention refers to the viscosity of a coating material obtained by diluting silicone gums having a viscosity of several hundred thousand mPa.s or more with a 30% toluene solution.

According to another embodiment of the present invention, it is preferred that the silicone release composition comprises an alkenyl polysiloxane, a hydro pre-polysiloxane, a surfactant and a platinum chelate catalyst.

The polyester film used in the present invention is not limited in its kind, but conventionally known ones known as base films of silicone release coatings can be used. In the present invention, the polyester based resin is mainly described, but the substrate of the silicone release film of the present invention is not limited to these polyester sheets or films. The polyester constituting the film refers to a polyester obtained by polycondensing an aromatic dicarboxylic acid and an aliphatic glycol. 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) 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. In addition, the base film according to the present invention can use a uniaxial or biaxial oriented film having high transparency, excellent productivity and processability, and a corona discharge treated film for improving the adhesion of silicon.

Next, the silicone release composition of the silicone release film according to the present invention comprises an alkenyl polysiloxane, a hydro pre-polysiloxane, and a platinum chelate catalyst.

The alkenyl polysiloxane in the constitution of the silicone mold-releasing composition according to the present invention may be of any type such as addition type, condensation type and ultraviolet ray curing type.

[Chemical Formula 1]

Where M and N are integers greater than or equal to zero.

The alkenyl polysiloxane contains an alkenyl group in the molecule, and an alkenyl group may be present in any part of the molecule, and preferably at least two alkenyl groups are present. It is advantageous to use an alkenylpolysiloxane having a viscosity of 1000 to 10,000 mPa · s in order to improve the adhesion of the base material of the release coating layer.

Further, according to the present invention, the composition further comprises a peelability-adjusting additive in order to balance the peel strength and the peel strength between the light peelable / heavy release film.

Preferably, the release force regulator is an organopolysiloxane resin, and it is preferable that the release force regulator is 0.1 to 5 parts by weight based on 100 parts by weight of the alkenyl polysiloxane.

More preferably, the releasability adjusting agent may be an organopolysiloxane resin containing a hydroxyl group or an organopolysiloxane resin containing an alkenyl group.

According to a preferred embodiment of the present invention, it is preferable that the release force regulator is an organopolysiloxane resin containing a ratio of hydroxyl group / alkenyl group of 0.1 to 0.5.

According to another preferred embodiment of the present invention, the silicone mold release composition preferably contains 0.5 to 5% by weight of solids.

Hereinafter, the present invention will be described in more detail with reference to examples, but it goes without saying that the present invention is not limited to these examples.

Example 1

A silicone mold release composition having a total solid content of 5% by weight was prepared and coated to a thickness of 10 microns using a polyester film having a corona discharge treated with a thickness of 50 탆 for the production of a release film. After the application, the film was heat treated in a hot air drier at 150 ° C for 20 seconds to prepare a silicone release film. In this Example, 5 wt% of silicon main material and 5 wt% of catalyst were mixed at a ratio of 5% with respect to the main material, and toluene was used as a solvent based on 80 wt%. Each component is shown in Table 1 below.

Example 2

The procedure of Example 1 was repeated except that the release power adjusting agent was added in an amount of 0.1 wt% as shown in Table 1 below.

Example 3

The procedure of Example 1 was repeated except that the release power adjusting agent was added in an amount of 0.3 wt% as shown in Table 1 below.

Example 4

The procedure of Example 1 was repeated except that the peel strength adjusting agent was added in an amount of 0.5 wt% as shown in Table 1 below.

Example 5

The procedure of Example 1 was repeated except that 1.0 wt% of release power adjuster was added as shown in Table 1 below.

Example 6

The procedure of Example 1 was repeated except that the release power adjusting agent was added in an amount of 1.5 wt% as shown in Table 1 below.

Constituent Compounding ratio (wt%) Clearing Heavy Example 1 Example 2 Example 3 Example 4 Example 5 Example 6 Silicon main material
(Shinetsu KS847H, solid content 30%) 5 5 5 5 5 5 Peel strength adjusting agent
(Shin-Etsu Co., Ltd. X-92-158) 0 0.1 0.3 0.5 1.0 1.5 Catalyst (Pt catalyst of Shin-Etsu Co.)
5% of main ingredient ratio 0.25 0.25 0.25 0.25 0.25 0.25 Solvent (toluene) 80 80 80 80 80 80

Experimental Example 1

The peeling strength of the release film produced through Examples 1 to 6 was measured as follows. The results are shown in Table 2 below. Example 1 was used as a light release film, Examples 2 to 6 were used as a middle release film, and physical properties were analyzed using an adhesive tape for analysis.

- Sample Preparation

① Silicon-coated measurement samples were stored at 25 ° C and 65% RH for 24 hours.

(2) An acrylic standard adhesive tape (TESA7475) was attached to the silicon coated surface, and the sample was pressed at room temperature (25 ° C) under a load of 20 g / cm ² for one day,

- Measuring instrument: chem-instrument AR-1000

- How to measure:

① 180 ° peel angle, peel rate 30 cm / min

② Sample size 510mm x 1500mm, Peel force measurement size 500mm x 1500mm

[Table 2] Comparison of physical properties of adhesive tape for analysis (TESA7475) Item Clearing Heavy Example 1 Example 2 Example 3 Example 4 Example 5 Example 6 Peel force (gf / inch) 20.1 25.6 31.7 40.5 58.9 67.1 Heavy / light separation - 1.27 1.57 2.01 2.93 3.34

Experimental Example 2. Measurement of Stability over Time

The releasing films prepared in Examples 1 to 6 were measured by dividing the aging peeling force at 60 占 폚 by 1 day and 7 days using an analytical tape to confirm the aging stability as follows. Table 3 shows the results. It was confirmed that as the content of the release agent to be added in the heavy release film was increased, the stability with time was also lowered, which proved to be a problem.

- Sample Preparation

① Silicon-coated measurement samples were stored at 25 ° C and 65% RH for 24 hours.

(2) An acrylic standard adhesive tape (TESA7475) was applied to the silicon coated surface, and the sample was pressed at 60 ° C under a load of 20 g / cm ² for 1 day and 7 days,

- Measuring instrument: chem-instrument AR-1000

- How to measure:

① 180 ° peel angle, peel rate 30 cm / min

② Sample size 510mm x 1500mm, Peel force measurement size 500mm x 1500mm

- Measurement data: The peel force unit is gf / in, and the measured value is measured five times to calculate the average value

- Calculate the percentage change over time by dividing the 7th day measurement value by the 1st day measurement value.

Item Clearing Heavy Example 1 Example 2 Example 3 Example 4 Example 5 Example 6 60 ℃ 1 day peeling force 22.1 27.9 32.9 43.1 59.9 69.3 60 ℃ 7 days Peeling force 24.8 33.2 41.4 54.7 81.8 99.8 (7 days - 1 day) / 1 day (%) 12.2% 19.0% 25.8% 26.9% 36.6% 44.1%

Experimental Example 3. Measurement of peeling strength of double-sided adhesive

In order to confirm the balance in an actual NCF-type adhesive, a pressure-sensitive adhesive using the double-side adhesive ratio shown in the following Table 4 was coated by a gravure coating method and dried, followed by lamination of the lightly releasing film at room temperature. The coating amount of the double-sided pressure-sensitive adhesive was selected to be 30 μm after the gravure roll mesh was selected. Both the release film and the double-sided adhesive were dried by a thermal drying method. Thereafter, the release force was measured while removing the release release film, and furthermore, the heavy release film was measured. Specific embodiments are as follows, and the results are as shown in Table 5 below.

- Sample Preparation

① Apply double-sided adhesive over the silicon-coated heavy-duty reseed sample

② Lightly peel off the film by laminating it on it

③ After drying, stored at room temperature for 3 days under a load of 20g / cm ²

④ After storing, make sample in 1 inch size and measure property

- Measuring instrument: chem-instrument AR-1000

- How to measure:

① 180 ° peel angle, peel rate 30 cm / min

- Measurement data: The peel force unit is gf / in, and the measured value is measured five times to calculate the average value

- Calculate the percentage change over time by dividing the 7th day measurement value by the 1st day measurement value.

Constituent Compounding ratio (wt%) Acrylate resin
(TOYOTA INK Co., EX332, solid content 30%)) 50 Curing agent (Toy ink company BK432) 0.3 Solvent (toluene) 80

Item Clearing Heavy Example 1 Example 2 Example 3 Example 4 Example 5 Example 6 Peel force (gf / inch) 2.3 2.6 3.4 4.3 6.5 7.1 Heavy / light separation - 1.13 1.48 1.87 2.83 3.09

Experimental Example 4

The analytical adhesive tape and double-sided adhesive agent data were used to confirm the lifting phenomenon of the NCF type adhesive due to the actual peeling force imbalance in Table 6 below. As a result of the confirmation, it is confirmed that the adhesive is stable without peeling of the adhesive when the ratio of the adhesive tape for analysis or the double-sided adhesive agent is more than 2 times (heavy / light peeling).

Item Clearing Heavy Example 1 Example 2 Example 3 Example 4 Example 5 Example 6 Adhesive tape for analysis
(Heavy / light separation) - 1.27 1.57 2.01 2.93 3.34 Double-sided adhesive
(Heavy / light separation) - 1.13 1.48 1.87 2.83 3.09 Removal of adhesive - × × △ ○ ○

 Adhesive swelling phenomenon matching through analytical adhesive tape and double-sided adhesive agent data

: Poor,?: Normal, good: good

Claims (6)

A release film comprising a polyester film and a coating layer applied on at least one side of the polyester film at least once with a silicone release composition,
Wherein the film satisfies the following formulas (1) to (4) simultaneously:
0.8? A? 2.0 - (Formula 1)
1.0? B? 2.0 - (Formula 2)
1000? C? 10,000 --- (3)
1.5? D? 3 - (4)
Here, A represents the value of the 7-day aged peel strength / 1-day aged peel strength ratio, and B represents the molar ratio of the Si-H group of the hydrolytic polysiloxane / Si-alkenyl group of the alkenyl polysiloxane used in the coating layer C represents the viscosity (unit: mPa.s) of the alkenyl polysiloxane used in the coating layer, and D represents the value of the releasing film peeling force ratio (heavy peeling / light peeling).
The silicone release film of claim 1, wherein the silicone release composition comprises an alkenyl polysiloxane, a hydro pre-polysiloxane, a surfactant, and a platinum chelate catalyst.
The silicone release film according to claim 1 or 2, wherein the releasing composition comprises an organopolysiloxane resin containing a hydroxyl group or an alkenyl group as a releasing force modifier.
The silicone release film according to any one of claims 1 to 3, wherein 0.5 to 5 parts by weight of an organopolysiloxane resin is added to the releasing composition as a releasing force adjusting agent with respect to 100 parts by weight of the alkenyl polysiloxane.
The silicone release film according to any one of claims 1 to 3, wherein the releasability adjusting agent is an organopolysiloxane resin containing a hydroxyl group / alkenyl group in a proportion of 0.1 to 0.5.
The silicone release film according to claim 1 or 2, wherein the silicone release composition contains 0.5 to 5% by weight of solids.