KR20050120253A - Silicone release polyester film - Google Patents

Abstract

The present invention relates to a silicone release polyester film coated with a silicone release solution containing an epoxy compound and a silane compound having excellent love stability after aging and heat aging. In the case of a release film having such a silicone release solution coating layer, The polarizing plate release film, the MC release film and the transfer coating due to the effect of improving the ease of release fracture behavior with the adhesive in the release application, and can be provided for electrical and electronic applications and other applications requiring uniform release properties. A silicone release polyester film having an advantage of a release film advantageous to the anticorrosion, comprising a polyester film or sheet and a silicone release layer coated with a silicone release solution on at least one side of the film or sheet, wherein the silicone release solution 4 to 30% by weight of hexenylpolysiloxane or vinylpolysiloxane, It characterized by de-hydrogen polysiloxane 0.02 ~ 1% by weight, the epoxy compound 0.1% to 0.3% by weight of a silane compound consisting of 0.1-0.3 wt%, chelate platinum catalyst, 0.0005 ~ 0.005% and a residual amount of water and polyvinyl alcohol.

Description

Silicone mold release polyester film {SILICONE RELEASE POLYESTER FILM}

The present invention relates to a silicone release polyester film, and more particularly, to a silicone release polyester film coated with a silicone releasing solution containing an epoxy compound and a silane compound having excellent aging stability and love-off properties after heat aging. .

In general, silicone chemistry has been started in areas where a curing system is needed, such as paint, rubber, sealant, adhesive, etc., and has been used for separating an adhesive layer from a release layer due to low surface energy. The release layer can be obtained by applying a release agent to a substrate such as a plastic film, sheet, paper, or nonwoven fabric. For example, EP 0527080, JP 64-005838, US 5672428 describes a technique of applying a release layer during molding of a plastic film or sheet. It is. In the case of the plastic film used as a base material to improve the interfacial adhesion between polyester and silicon, the surface tension is increased by chemically treating the surface by corona treatment or plasma treatment to improve the wettability of the release liquid or in the case of the polyester film Highly polar polymers such as highly modified modified polyesters, partially hydrolyzed ethylene-vinylacetate copolymers, special acrylic copolymers, and polyvinyl butyral are used.

Another class of technologies has been reviewed such as US 4087585, US 4677160, JP 64-005838 in order to ensure the stability of the adhesion promoter and curing system to conventional silicones, such as EP 0527080, US 5672428, US 5728339. It is also applied in the manufacturing process, and it has been announced that silicone is effective in improving adhesion and adhesion with a film, and the use technology is related to the use of an adhesion improving agent such as a water dispersion ester, a water dispersion acrylic, and an alkoxy silane. The usefulness of adhesion improvement with silicone is mentioned. However, the experiments and the results of this researcher found that the problem occurred in terms of Bath-Life. As reported by KWAllen et.al, shear, acid and base (pH) As a result of the dependence, there was a problem of rapid swelling and gelation of the liquid, which resulted in poor filtering properties and appearance properties of the coated film in the coating process. In addition, since the coating process in the film manufacturing process undergoes a deformation process called stretching, a problem that requires great attention to the adhesion and smoothness of the release agent and the substrate is additionally generated. The deterioration of the 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, partial crosslinking and lack of flexibility in crosslinked release films after manufacture, and rub-off or delayed rub-off due to micro reactions between polyester and cross-linker. The 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 by applying and drying the silicone release liquid on at least one side of the film or sheet during the polyester film manufacturing process to reduce the cost of off-line (OFF-LINE) In short, to provide a manufacturer-friendly silicone release polyester film.

In addition, an object of the present invention is to provide a silicone release polyester film with uniform time stability and peel release properties of the silicone layer.

It is also an object of the present invention is suitable for electrical and electronic applications and other applications requiring uniform release properties, and the weakening of the adhesive strength of the adhesive layer laminated with the silicon layer, which is a problem caused by silicon transfer in the process, and poor printing on the opposite side of the adhesive layer. It is to provide a silicone release polyester film that can solve problems such as causing.

Silicone release polyester film coated with a silicone release liquid containing an epoxy compound and a silane compound according to the present invention for achieving the above object is coated with a silicone release liquid on a polyester film or sheet and at least one side of the film or sheet A silicone release polyester film comprising one silicone release layer, wherein the silicone release liquid is 4 to 30% by weight of hexenylpolysiloxane or vinylpolysiloxane, 0.02 to 1% by weight of hydrogen polysiloxane, 0.1 to 0.3% by weight of epoxy compound, silane compound It is characterized by consisting of 0.1 to 0.3% by weight, chelate platinum catalyst 0.0005 to 0.005% by weight and the balance of water and polyvinyl alcohol.

The silane compound is preferably tetramethoxysilane, tetraethoxysilane or a mixture thereof.

In the present invention, the polyester film or sheet is characterized in that the corona treatment through an inline coating process.

In addition, the silicone release layer in the present invention is characterized in that it is formed in a fixed to coat the silicone release liquid while evaporating the solvent at the same time as the stretching process of the in-line release polyester method of the polyester film manufacturing process.

In addition, the thickness of the silicon release layer formed after the silicon release solution is dried in the present invention is characterized in that the 0.1 ~ 2㎛.

The silicon used in the present invention exhibits heterogeneous characteristics due to the low surface energy of the dimethyl group, the wide angle and rotational force between the silicon atom and the oxygen atom, and the alkenyl group at a specific position in addition to the basic characteristics of the silicon structure. The introduction of the functional group causes the reaction with the curing agent to form a chain structure. At this time, the alkenyl group to be introduced generally uses a vinyl group, but a problem of a change in peel force is known in applications in which a high peel release rate is required. As a result of the study on the silicon structure which is less affected by the peeling rate, the result of obtaining the uniform peeling force was obtained when the hexenyl polysiloxane selected by the researcher was used. Also, when the hexenyl polysiloxane was used, the rapid curing and the aging change were small. He also found that stable release force can be obtained.

Due to the silicon's structural characteristics, silicon and oxygen have a wide molecular angle and favorable rotation, so gas permeability and water permeability are good, but in order to overcome structural problems with poor acid and alkali resistance, a silicone film is used by using a dispersible epoxy compound and a silane compound. The flexibility is now possible to control. In order to solve the above problem, the patent application No. 2003-86685 of the inventors of the present invention prior to this is a silicone film by using "vinyl group-containing organo resin" instead of water-dispersible epoxy compound and silane compound in the present invention The invention which controlled the flexibility of this is described.

In the present invention, it was confirmed that the smoothness, solvent resistance, and love-off properties after heat aging of the release coating were improved by adding the epoxy compound and the silane compound to the silicone release liquid.

Therefore, the silicone release polyester film according to the present invention is a pressure-sensitive adhesive label, a polarizing plate release film, MLC [MLCC (Multi-Layer-Ceramic Capacitor) for use in the industry that can be advanced and differentiated in an industry requiring various release applications. ] Can be used in various fields such as release carrier used for manufacturing, release film for solar control, release protective film for LCD, LCD overlay, medical pathy, adhesive tape, etc. In particular, in the case of MLC, it has to have excellent peeling characteristics in the process of peeling the ceramic sheet by drying and solidifying a liquid ceramic having excellent process running characteristics and specific viscosity during ceramic molding. This is because both sides of the polyester surface layer have different roughness, so that the layer having a relatively high surface roughness improves the running and processing characteristics.Since the layer having a low surface roughness is coated with silicon, the ceramic coating layer is more uniform and thinner. In addition, it was possible to confirm that the ceramic layer can be uniformly peeled off by a certain force when peeling off the release film in addition to the excellent dielectric properties. Carrier) also confirmed excellent quality.

Silicone emulsion release liquid of the silicone release polyester film according to the present invention, hexenyl polysiloxane or vinyl polysiloxane 4-30% by weight, hydrogen polysiloxane 0.02-1% by weight, epoxy compound 0.1-0.3% by weight, silane compound 0.1-0.3 It is preferred to include by weight%, chelated platinum catalyst 0.002 to 0.005% by weight and the balance of water and polyvinyl alcohol.

The average particle size of the hexenyl polysiloxane aqueous emulsion release agent is 0.01 to 2 μm and the viscosity of the release liquid composed of the composition is 1.1 to 5.6 centipoise, preferably 1.2 to 3.5 centipoise. The higher the viscosity, the higher the pressure required to supply the liquid, there is a problem that it is difficult to ensure the stability of the wet state.

Silicone emulsion release liquid of the silicone release polyester film according to the present invention is polyester, polypropylene, polyethylene, polyvinyl chloride, nylon, the film of the laminated material of the plastic; Kraft paper; It can be applied directly on the nonwoven fabric, cloth, etc., and the total solid 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.

The molecular structure of hexenyl polysiloxane and hydrogen polysiloxane in the silicone emulsion release liquid of the silicone release polyester film according to the present invention is as follows.

In addition, the molecular structure of the epoxy compound used in the present invention is as follows.

When the epoxy compound and the silane compound included in the silicone release liquid according to the present invention are used in an amount of less than 0.1% by weight in the total weight of the silicone release liquid, the flexibility of the polyester and the silicone film is good, the solvent resistance is poor, and the love-off (Rub-off) occurred and the stability over time was inferior, and when the amount of more than 0.3% by weight was used, the problem of the reaction site disturbance and the wettability characteristic of hexenyl polysiloxane and hydrogen polysiloxane was excessively suppressed. As a result, an undesirable result was obtained due to the increase in peel force. The substrate is coated with the release agent after a corona treatment is performed on a release liquid and a substrate such as polyester for strong chemical bonding between the coextruded substrate and the release layer, and the thickness of the substrate is 2 mm or less, preferably 5 To 1500 μm. It is preferable that the said silane compound is tetramethoxysilane, tetraethoxysilane, or a mixture thereof.

The thickness of the release liquid in the wet state before stretching the polyester film is preferably 7.6 μm to 25.4 μm, and the thickness after the drying process is preferably 0.1 to 2 μm, and the surface number average roughness of the silicone-coated polyester film. 0.003-1 micrometer is suitable, More preferably, it is 0.005-0.6 micrometer. If the thickness of the silicon film is more than 2㎛ after drying, the silicon coated surface and the uncoated surface are wound at a certain pressure and blocking occurs. After aging (24 hours, 50 ℃, 95% RH) Rub-off) could be confirmed. In addition, the process conditions for coating the release liquid and stretching at the same time as thermosetting drying, stretching is 2.5 to 12 times, drying and curing temperature conditions 60 ℃ ~ 250 ℃, wind speed 8 ~ 40m / s and residence time in the dryer 8 Seconds to 20 minutes, more preferably about 10 seconds to 5 minutes.

In addition, the thermal shrinkage properties of the thermal stability evaluation items of the coextruded polyester release film prepared using the silicone release liquid after heat-treated the film in an oven at 150 ℃ for 30 minutes in the longitudinal shrinkage of 0.5% to 2.5% , The transverse heat shrinkage is preferably -0.03% to 1.5%, more preferably in the longitudinal direction, the heat shrinkage is 0.5% to 2%, and the transverse heat shrinkage is -0.01% to 1.0%. When the heat shrinkage in the lateral direction was more than 1.5% in an oven at 150 ° C. for 30 minutes or more, it was found that the melt-melt adhesive was not suitable for release use using a hot melt adhesive. As a result, the non-uniform release force may occur due to the difference in thermal conductivity during the instant shrinkage or expansion of the silicone layer and the polyester layer of the release film.

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

Examples 1 to 4 are corona-treated silicone release liquids consisting of the components shown in Table 1, residual amounts of water, and polyvinyl alcohol, in particular varying the content of ethoxy compounds and silane compounds (using tetraethoxysilane). Coating on the polyester surface to produce a silicone release polyester film.

[Comparative Example]

Comparative Examples 1 to 3 have the composition shown in Table 1, Comparative Example 1 except for the silane compound which is a feature of the present invention, Comparative Example 2 except for the epoxy compound, Comparative Example 3 is a silane compound and an epoxy compound A silicone release polyester film was prepared by coating a silicone release liquid except for all on a polyester surface.

Table 1 Composition of silicone release liquid and characteristics of silicone release polyester film

Item Release solution composition (% by weight) Peel force (average) Love off after heat aging Content Coating A B C D E Example 1 8 0.02 0.002 0.1 0.1 16 ◎ ◎ ○ Example 2 8 0.02 0.002 0.1 0.2 19 ○ ○ △ Example 3 8 0.02 0.002 0.2 0.3 17 △ △ △ Example 4 8 0.02 0.002 0.2 0.2 18 △ △ △ Comparative Example 1 8 0.02 0.002 0.1 0 22 ▽ ▽ ○ Comparative Example 2 8 0.02 0.002 0 0.1 21 ▽ ▽ ○ Comparative Example 3 8 0.02 0.002 0 0 22 ▽ ▽ ○ Remarks A; hexenyl polysiloxane, B; Hydrogen polysiloxanes, C; chelate platinum catalyst, D; Epoxy compound E; Tetraethoxysilane (excellent); Good; △ normal; ▽ under

As can be seen in Table 1, Examples 1 to 4 in which the silicone release solution containing the epoxy compound and the silane compound according to the present invention are coated on a corona-treated polyester film do not include an epoxy compound and / or a silane compound. Compared to Comparative Examples 1 to 3 coated on the polyester film with a silicone release liquid did not have excellent interfacial adhesive strength and excellent release properties. In other words, the silicone release layer according to the present invention improves interfacial adhesion with physical and chemical bonding with a polyester film, so that it is easy to peel off after lamination with a standard adhesive tape during peel release measurement, and rubbed strongly with fingers after solvent and heat aging conditions. Even when the silicon layer showed a stable performance.

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

Experimental Example

Release Peel Analysis

The analysis was conducted according to the Finat Test Method 1. Standard adhesive tape is TEK7475 attached to the surface of silicone release film with 2kf load and laminated, and left for 1 day, peeling angle 180 degrees, peeling speed 0.3m / min, measuring size length 100㎜, width 25.4mm, peel force unit g / in, and the measured value was measured 5 times and the average value was computed.

Rub-off test after heat aging

Using a circulating oven, left the silicone-coated film under the condition of 50 ℃ and 95% RH for 24 hours, and then pushed it hard several times with a finger to perform a love-off test to confirm the adhesion between the cured silicone film and the polyester film. It was.

Solvent resistance test

It was judged that the case where it was peeled off when the methyl isocertone was buried in a cotton swab and the silicone layer was rubbed out of the coextruded release polyester film layer was satisfactory.

Coating evaluation

Visual observation was used to evaluate the coating properties. The uniformity of the applied liquid and defects after application and drying were observed.

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 silicone release polyester film according to the present invention, in the case of coating the polyester film or sheet with a silicone release liquid containing an epoxy compound and a silane compound, the adhesive properties of the polyester layer and the silicone layer It has the effect that the love-off properties after heat aging is very excellent.

In addition, in the case of the release film having the silicone release liquid coating layer, the release release behavior with the pressure-sensitive adhesive in the release application can be improved, so that it can be provided for electric and electronic applications and other applications requiring uniform release properties. Due to the polarizing plate release film or MLC release film and there is an advantage suitable for the release film advantageous for the transfer coating method.

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

Claims (5)

A silicone release polyester film comprising a polyester film or sheet and a silicone release layer coated on at least one side of the film or sheet with a silicone release liquid, The silicone release liquid is 4 to 30% by weight of hexenyl polysiloxane or vinyl polysiloxane, 0.02 to 1% by weight of hydrogen polysiloxane, 0.1 to 0.3% by weight of epoxy compound, 0.1 to 0.3% by weight of silane compound, 0.0005 to 0.005% by weight of chelate platinum catalyst. And a residual amount of water and polyvinyl alcohol. The silicone release polyester film according to claim 1, wherein the silane compound is tetramethoxysilane, tetraethoxysilane or a mixture thereof. The silicone release polyester film of claim 1 or 2, wherein the polyester film or sheet is corona treated through an inline coating process. According to claim 3, wherein the silicone release layer is a silicone release polyester, characterized in that in the process of coating the silicone release liquid while evaporating the solvent and at the same time as the stretching step of the in-line release polyester method in the polyester film manufacturing process film. The silicone mold release polyester film according to claim 1 or 2, wherein the silicone mold release layer formed after the silicone mold release liquid is dried has a thickness of 0.1 to 2 µm.