KR20050120252A - Silicone release polyester film - Google Patents

Abstract

The present invention not only has excellent release property, but also includes a zirconium compound that can improve adhesion between the polyester substrate and the silicon interface and can be easily peeled off from the adhesive component, and also has excellent solvent resistance and ensures stability of the release layer. It relates to a silicone release polyester film coated with a release liquid. To this end, the silicone release polyester film according to the present invention is a polyester release film comprising a polyester film or a sheet and a release layer coated on at least one side of the film or sheet with a release solution, wherein the release solution is hexenyl polysiloxane. Or 4 to 30% by weight of vinyl polysiloxane, 0.8 to 3% by weight of hydrogen polysiloxane, 0.003 to 0.5% by weight of zirconium compound, 0.002 to 0.005% by weight of chelated platinum catalyst, 0.9 to 1.1% by weight of surfactant and residual amount of polyvinyl alcohol Characterized in that consisting of.

Description

Silicone mold release polyester film {SILICONE RELEASE POLYESTER FILM}

The present invention relates to a silicone release polyester film, and more particularly, excellent in releasability, the adhesion between the polyester substrate and the silicon interface is improved and can be easily peeled off from the adhesive component, and also excellent in solvent resistance It is related with the silicone mold release polyester film which can ensure the stability of a mold release layer.

The general release layer as shown in FIG. 1 can be obtained by applying a release agent to a substrate such as a plastic film, sheet, paper, or nonwoven fabric. US Pat. Nos. 5,672,428, and 5,728,339 describe techniques for applying a release layer during plastic film or sheet molding.

When the release layer is a silicone release layer, in the case of a plastic film used as a substrate to improve the interfacial adhesion between polyester and silicon, the surface is chemically treated by corona treatment, plasma treatment, or the like. Highly polar polymers such as large modified polyesters, partially hydrolyzed ethylene-vinylacetate copolymers, special acrylic copolymers, and polyvinyl butyral are used for treatment.

Conventional release films have a primer layer formed first, and secondly processed off-line, as described in US Pat. No. 5,298,325, in order to improve the release property with the adhesive layer and the adhesion between the release layers. Except for the case of manufacturing by one application, if the adhesive strength between the release layer and the substrate is increased, the peelability from the adherend is lowered. On the contrary, if the mold release property is improved and the peelability is increased, the adhesive strength with the substrate is lowered. You have a problem.

In order to solve this problem, US Pat. No. 5,672,428, US5,728,339 applies a silicone-based emulsion-based release agent that is silicone-coated once in the polyester manufacturing process to apply water-dispersible poly to improve adhesion with the film when applied to a plastic film Adhesion enhancers such as esters, water-dispersible acrylics and glycidoxy alkoxysilanes are used.

In addition, in-line coating undergoes a deformation process called stretching, and thus, a problem that requires great attention to adhesion and smoothness of the release agent and the substrate is generated. The inferior smoothness of the release layer in the in-line release agent coating is due to the flexibility of the silicone backbone. Phenomena caused by differences in crosslinking rates due to nonuniformity, partial crosslinking and lack of flexibility in crosslinked release films after manufacture, and rub-off or delayed rubb- ble due to micro reactions between polyester and cross-linker. off) phenomenon occurs.

In addition, in the process of the general adhesive label having the configuration of FIG. 1, there are problems such as weakening of the adhesive force of the pressure-sensitive adhesive layer laminated with the silicon layer and poor printing on the opposite side of the pressure-sensitive adhesive layer during silicon transfer.

The present invention has been made to solve the above problems, an object of the present invention is to significantly increase the interfacial adhesion between the polyester film and the release agent, and at the same time the release of silicone coated with a release liquid containing a zirconium compound excellent in peel force. It is to provide a polyester film.

In addition, the object of the present invention is to ensure the smoothness of the release coating and to ensure a uniform adhesive force between the polyester substrate and the silicon interface, and to secure the electrostatic and runability, which is the biggest disadvantage of the polyester substrate on the opposite side of the silicone coating layer In order to provide a silicone release polyester film coated with a release liquid containing a zirconium compound that can reduce the two processes of the user process and reduce the overall cost and problems by applying inline in the difficult point.

In addition, the object of the present invention can be laminated with a release carrier, a solar control adhesive film when manufacturing a pressure-sensitive adhesive label, polarized film (ML) (Multi-Layer-Ceramic Capacitor) for the purpose to be advanced and differentiated in various release markets To provide a silicone release polyester film coated with a release liquid containing a zirconium compound, which can be used in various fields such as LCD protective release film, overlaid use, and medical pathy.

Silicone release polyester film coated with a release liquid containing a zirconium compound according to the present invention for achieving the above object, a release layer coated with a polyester film or sheet and at least one side of the film or sheet with a release liquid A polyester release film comprising, the release liquid is 4 to 30% by weight of hexenyl polysiloxane or vinyl polysiloxane, 0.8 to 3% by weight of hydrogen polysiloxane, 0.003 to 0.5% by weight of zirconium compound, 0.002 to 0.005% by weight of chelated platinum catalyst, It is characterized by consisting of 0.9 to 1.1% by weight of surfactant and the balance of water and polyvinyl alcohol.

Here, the zirconium compound is composed of hydrated zirconium compounds, zirconium carboxylates / chelates, zirconium alkoxides, zirconium chelates, and zirconium acetate. It is preferable to include at least one substance in the.

In addition, the release solution is characterized in that it further comprises hydroxy ethyl cellulose (Hydroxy Ethyl Cellulose).

In addition, the polyester film or sheet is preferably corona treated through an inline coating process.

In addition, the thickness of the release layer formed after the release liquid is dried is preferably 0.1 ~ 2㎛.

According to the present invention, the release solution is corona treated unstretched sheet or corona treated uniaxial stretched film or corona treated sequential stretching film and simultaneous biaxial stretching (Simulataneous biaxial stretching) immediately before the corona treated polyester , A release film applied to a polyethylene or polypropylene base material.

Silicone aqueous emulsion release liquid according to the present invention is 4 to 30% by weight of hexenyl polysiloxane or vinyl polysiloxane, 0.8 to 3% by weight of hydrogen polysiloxane, 0.003 to 0.5% by weight of zirconium compound, 0.002 to 0.005% by weight of chelated platinum catalyst, surfactant 0.9 to 1.1% by weight and the balance of water and polyvinyl alcohol and / or hydroxy ethyl cellulose.

The average particle size of the hexenyl polysiloxane aqueous emulsion release agent is from 0.01 to 1 μm and the viscosity is from 1.1 to 5.6 centipoise, preferably from 1.2 to 3.5 centipoise. The higher the viscosity, the more significant pressure is required to supply the liquid, there is a problem that is difficult to ensure the stability of the wet state. The silicone aqueous emulsion release liquid of the present invention may be directly applied on polyester, polypropylene, polyethylene, polyvinyl chloride, nylon, film kraft paper non-woven fabric, cloth, etc. of the laminated material of the plastic, hexenyl in the silicone release liquid The polysiloxane or vinylpolysiloxane solids content is 4 to 30% by weight, more preferably 6 to 30% by weight. The total solids content is 4 to 30% by weight, more preferably 6 to 20% by weight. Less than 4% by weight of the release liquid has a low viscosity due to the film release and insufficient curing, such as release property problems, and more than 30% by weight of non-uniform coating problem due to the viscosity rise occurs.

In addition, the zirconium compound in the release liquid used in the present invention is a chemical material that can improve the interfacial adhesion between the substrate such as silicone polymer and PET, and the stability of physical properties when used in 0.001 to 1% by weight, preferably 0.003 to 0.5% by weight. It was confirmed that can be secured. When the zirconium compound is 0.003% or less, the adhesion of the base material between PET and silicone is low, and the silicon unreacted material is extracted. When the film is used during the film manufacturing process using 0.5 wt% or more, the crack of the silicon film during the stretching process and after the stretching process ( CRACK) was confirmed and accordingly the peeling material properties were significantly reduced. The substrate is coated with the release liquid after the corona treatment is performed for strong chemical bonding between the substrate and the release layer, and the thickness of the substrate may be 2 mm or less, preferably 20 to 1500 μm. In addition, a chemical treatment layer such as a primer layer such as the zirconium compound may be first formed on the release layer forming surface of the substrate in order to strengthen conventional chemical bonding.

The zirconium compounds in the composition of the release liquid used in the present invention are hydrated zirconium compounds, zirconium carboxylates / chelates, zirconium alkoxides, zirconium chelates and zirconium chelates. It is preferable to include at least one substance in the group consisting of acetate (Zirconium Acetate).

On the other hand, the release liquid preferably further comprises hydroxy ethyl cellulose (Hydroxy Ethyl Cellulose).

The thickness of the release liquid in the wet state before stretching of the silicone release polyester film is 7.6 µm to 25.4 µm, and the thickness after the stretching and drying process is preferably 0.1 to 2 µm, and the surface average roughness of the silicone-coated polyester film is 0.01 to 1 μm is suitable and more preferably 0.01 to 0.6 μm. If the coating thickness is more than 2㎛ after drying, blocking occurs as the silicon coated surface and the uncoated surface are wound at a constant pressure, and after aging (24 hours, 50 ℃, 95% RH), crushing phenomenon (Rub- off). The crushing phenomenon of the silicon layer is caused by the lack of adhesion between the silicon layer and the substrate, and as shown in Examples and Comparative Examples below, particularly in a silicone release polyester film coated with a release liquid containing no zirconium compound. It was confirmed to be a problem.

In addition, it is a process condition for coating with release liquid and stretching at the same time as thermosetting drying, stretching is 2.5 ~ 12 times, drying and curing temperature condition is 60 ℃ ~ 250 ℃, wind speed is 8 ~ 40m / s and residence time in dryer is 15 seconds To 20 minutes, more preferably 15 seconds to 1 minute.

In addition, in the thermal shrinkage measurement of the thermal stability of the polyester release film prepared after inline application using the silicone release liquid according to the present invention, the heat shrinkage in the longitudinal direction is 0.5% to 1.5%, the transverse heat shrinkage is -0.03 % To 1.0% is preferred, more preferably in the longitudinal direction the heat shrinkage is 0.5% to 1.0% and the transverse heat shrinkage is -0.01% to 0.4%. When the heat shrinkage was more than 0.5% at 150 ° C in a lateral direction of 150 ° C, it was found to be unsuitable for releasing use using a hot-melt pressure-sensitive adhesive. The silicone layer and the polyester layer of the release film are due to the difference in thermal conductivity during instant shrinkage or expansion.

In addition, according to the present invention, the release solution having the composition as described above corona treated unstretched sheet or corona treated uniaxial stretched film or corona treated sequential stretching film and simultaneous biaxial stretching (Simulataneous biaxial stretching) immediately before the corona It can also be applied to treated polyester, polyethylene or polypropylene substrates.

Hereinafter, the present invention will be described in detail through embodiments of the present invention. These examples are only for illustrating the present invention in more detail, it will be apparent to those skilled in the art that the scope of the present invention is not limited by these examples in accordance with the gist of the present invention. .

EXAMPLE

In Example 1 to Example 6, the composition shown in Table 1 and the composition of the remaining amount of water and polyvinyl alcohol, in particular, the composition of the hexenyl polysiloxane and zirconium compound (using zirconium acetate) varying in the content as shown in Table 1 Coating on the treated polyester surface produced a polyester release film.

[Comparative Example]

Comparative Examples 1 to 3 are composed of the composition of Table 1 and the residual amount of water and polyvinyl alcohol, which does not contain any zirconium compound and releases a release liquid that differs only from the content of hexenyl polysiloxane as shown in Table 1 on the polyester surface. Coating to prepare a polyester release film.

[Table 1] Release Liquid Composition

Item Release solution composition (% by weight) A B C D E Example 1 15 1.3 0.005 0.004 One Example 2 20 1.3 0.005 0.004 One Example 3 5 1.3 0.005 0.004 One Example 4 15 1.3 0.05 0.004 One Example 5 20 1.3 0.05 0.004 One Example 6 5 1.3 0.05 0.004 One Comparative Example 1 15 1.3 0 0.004 One Comparative Example 2 20 1.3 0 0.004 One Comparative Example 3 5 1.3 0 0.004 One Remarks A; hexenyl polysiloxane, B; Hydrogen polysiloxane, C; zirconium acetate, D; Platinum catalyst E; Surfactants

[Table 2] Properties of Polyester Release Film

Item Peel force (average) Unreacted Polysiloxane Content Content Coating thickness after drying Love Off After Aging Peel force after 1 day Peel force change after heat aging (%) Example 1 23 9 6 ◎ 0.24 ◎ Example 2 20 7 4 ◎ 0.3 △ Example 3 28 15 8 ○ 0.1 ◎ Example 4 30 13 14 ○ 0.24 ◎ Example 5 25 10 12 ○ 0.3 ○ Example 6 38 22 15 ○ 0.1 ◎ Comparative Example 1 30 33 8 ∇ 0.24 ∇ Comparative Example 2 29 30 5 ∇ 0.3 ∇ Comparative Example 3 32 42 15 ∇ 0.1 ∇ Remarks  Excellent ◎; Good ○; Usually Δ; Under

Table 2 is the result which showed the characteristic of the silicone mold release polyester film apply | coated with the mold release liquid of Examples 1-6 and Comparative Examples 1-3, respectively.

As can be seen in Table 2, Example 1 to Example 6 can be confirmed that the release liquid containing a zirconium compound is excellent in interfacial adhesion and excellent release properties because the coating on the surface of the corona-treated polyester substrate. In other words, the interfacial adhesion is improved by chemical bonding between the release layer and the polyester film, and therefore, it is easy to peel off after lamination with the standard adhesive tape and the solvent resistance is excellent under 50 ° C. and 95% RH conditions. The stability of the release layer was ensured even when rubbed strongly with a finger after 24 hours.

On the other hand, as in Comparative Examples 1 to 3, when the release liquid containing no zirconium compound was used, streaking defects (Ribbing) occurred in unstable coating state, and it was confirmed that the peeling force and the change over time were unstable. In addition, Comparative Examples 1 to 3 are data for observing the viscosity of the release solution in the wet state without using a zirconium compound, the physical properties according to the coating thickness after drying, and aging stability. As the thickness of the coating becomes thicker, the Rub-off phenomenon becomes more pronounced. Appeared.

Hereinafter, experimental examples applied to Examples and Comparative Examples according to the present invention.

Experimental Example

In the evaluation test used in the present invention, the test related to the peeling force measurement was performed using the AR1000 model of Chem Instruments, and the standard adhesive tape was laminated by attaching TESA7475 to the silicon release film surface with a load of 2k _f and a circulating oven (Covection oven, Heraeus company). , Model HC 4033) using a sample with 180 ° peeling angle and peeling speed 0.3m / min, width 4cm × 15cm, before and after thermal aging, measuring size is 100mm in length and 25.4mm in width. The peel force unit was g / in and the measured value was measured 5 times to calculate an average value.

Determination of peeling force change of adhesive tape after heat aging

After the silicone coating, the cured film was placed on the silicone coated surface with adhesive tape tesa7475 under a load of 2kg _f , and the laminated film was placed on a release film with 70g / ㎠ iron bar, stored at 23 ° C and 50% RH for 24 hours, and then AR1000 of ChemInstrument Using a model, the peel force (①) is measured at a speed of 0.3 m / min at a 180 degree peel angle. Stick the adhesive tape tesa7475 on the surface of the silicone cured film with a load of 2kg _f , and place the laminated material on the release film by putting 70g / ㎠ iron bar on the release film for 24 hours at 60 ℃ and 70% RH, and then take it out. Peel force (2) was measured as follows. The equation for obtaining the change in peeling force after heat aging shown in Table 2 is as follows.

Change of Peel Force of Standard Adhesive Tape = [(②-①) / ①] * 100

Determination of Unreacted Polysiloxane Content

The coating thickness of the film (③) was measured by XRF [X-Ray Fluorescence Spectrometer] Philips-minpal after the release liquid of Examples and Comparative Examples was applied and stretched and dried. After 24 hours of immersion in Methyl-Isobutyl-Ketone (MIBK), the film was taken out, MIBK solvent was volatilized in air, and the coating thickness (④) was measured using XRF [X-Ray Fluorescence Analyzer] Philips-minpal. The change of was observed. The formula for obtaining the unreacted silicon content shown in Table 2 is as follows.

Unreacted Silicon Content = [(③-④) / ③] * 100

Solvent resistance test

When the methyl iscer ketone was buried in a cotton swab and rubbed with the silicone layer coated with the release liquid of Examples and Comparative Examples in the release polyester film layer, it was judged that the peeling was insufficient and the peeling was not good.

Silicone Coating Thickness Measurement

It was measured using an X-ray fluorescence analyzer (XRF), Oxford LabLab 3000 model.

Rub-off test after Aging

Using Heraeus's Model HC 4033, the silicone-coated film with the release liquids of Examples and Comparative Examples was left at 50 ° C. and 95% RH for 24 hours, and then pushed several times with a finger and cured by Rub-off test. The adhesive properties of the silicone and the PET film were confirmed.

In the present specification, the present inventors describe only a few examples of various preparations and experiments performed by the present inventors according to the manufacturing method according to the present invention, but the technical idea of the present invention is not limited thereto and is variously modified by those skilled in the art. Of course, it can be carried out.

As described above, according to the polyester release film coated with a release liquid containing a zirconium compound according to the present invention, when the polyester film or sheet is coated with a release liquid containing a zirconium compound, the release property may be excellent. In addition, the adhesion between the polyester substrate and the silicon interface is improved and has an effect that can be easily peeled off from the adhesive component.

In addition, according to the present invention, it is excellent in solvent resistance and has the effect of ensuring the stability of the release layer even when rubbed strongly with a finger.

1 is a cross-sectional view of a typical adhesive label.

Claims (6)

A silicone release polyester film comprising a polyester film or sheet and a release layer coated on at least one side of the film or sheet with a release liquid, The release solution is 4 to 30% by weight of hexenyl polysiloxane or vinyl polysiloxane, 0.8 to 3% by weight of hydrogen polysiloxane, 0.003 to 0.5% by weight of zirconium compound, 0.002 to 0.005% by weight of chelating platinum catalyst, 0.9 to 1.1% by weight of surfactant, and Silicone release polyester film, characterized in that consisting of a residual amount of water and polyvinyl alcohol. The method of claim 1, wherein the zirconium compound is a zirconium compound (Aqueous zirconium compounds), zirconium carboxylates / chelates, zirconium alkoxides (zirconium alkoxides), zirconium chelates (Zirconium chelates) and zirconium acetate (Zirconium acetate (Zirconium acetate) Acetate) silicone release polyester film, characterized in that it comprises at least one material in the group consisting of. 3. The silicone release polyester film of claim 2, wherein the release liquid further comprises hydroxy ethyl cellulose. The silicone release polyester film according to any one of claims 1 to 3, wherein the polyester film or sheet is corona treated through an inline coating process. The silicone mold release polyester film according to any one of claims 1 to 3, wherein the thickness of the mold release layer formed after the mold release solution is dried is 0.1 to 2 µm. The release liquid according to any one of claims 1 to 3, wherein the release solution is corona treated unstretched sheet or corona treated uniaxial stretched film or corona treated sequential stretching film and simultaneous biaxial stretching (Simulataneous biaxial stretching) A release film, characterized in that it is applied immediately to a corona treated polyester, polyethylene or polypropylene substrate.