KR100710463B1 - High-transparent heat rejection pressure sensitive adhesives and coating film using the same - Google Patents

Abstract

The present invention relates to an acrylic pressure-sensitive adhesive and a pressure-sensitive adhesive coating film in which nano-sized metal oxide particles having infrared ray blocking performance are uniformly dispersed. The present invention provides a pressure-sensitive adhesive containing a metal oxide having an infrared (IR) blocking ability, wherein the pressure-sensitive adhesive contains an alkoxysilane or halide silane compound as a stabilizer of the metal oxide having the infrared (IR) blocking ability, Provided is a high-transparent insulating adhesive containing an alkoxysilane-based and halide-silane compound. In addition, the present invention provides a high-transparent insulating pressure-sensitive adhesive film formed of a high-transparent insulating adhesive as described above. According to the present invention, the transmittance in visible light is high, the infrared ray blocking rate is high, and the adhesive performance is excellent. In addition, process cost reduction and workability are greatly improved.

Transparent, heat insulation, pressure-sensitive adhesive, metal oxide, alkoxysilane, halide silane

Description

High-transparent insulation adhesive and its adhesive coating film {HIGH-TRANSPARENT HEAT REJECTION PRESSURE SENSITIVE ADHESIVES AND COATING FILM USING THE SAME}             

Figure 1 shows a graph of UV-VIS-NIR Spectroscopy of a high transparent film according to an embodiment of the present invention.

Figure 2 shows the difference between the layer structure (a) of the high-transparent insulating film according to the present invention and the layer structure (b) of the conventional high-transparent insulating film.

The present invention relates to a high-transparent insulating adhesive that can simultaneously impart infrared ray blocking performance and adhesion performance while having high transmittance to visible light, and more specifically, nano-size metal oxide particles having infrared ray blocking performance. It relates to an acrylic pressure-sensitive adhesive and a pressure-sensitive adhesive coating film dispersed uniformly.

Recently, the use of heat-insulating films using nanoparticles of metal oxides with infrared blocking capability is increasing day by day as a way to prevent the flow of heat through windows in buildings and vehicles, and to reduce indoor comfort and energy.

Infrared shielding metal oxides include indium tin oxide (ITO), antimony tin oxide (ATO), aluminum zinc oxide (AZO), and fluoro tin oxide : Many kinds are already known as metal oxides such as FTO), tin oxide (SnO2), and the like. These metal oxides have a high transmittance of visible light and a high blocking rate of infrared rays, which are hot wires, and thus, their use as an insulating material for imparting heat insulation of a transparent heat insulating film is increasing.

Conventionally, such a method of manufacturing a transparent thermal insulation film was applied to one side of the substrate by applying an infrared (IR) blocking agent using a binder dispersed in an organic solvent or alcohol, and a pressure-sensitive adhesive layer on the back side of the substrate (Korea Patent Publication No. 10-0214428, Korean Laid-Open Patent Publication No. 2003-0017311, Japanese Laid-Open Patent Publication No. 2000-24591, Japanese Laid-Open Patent Publication No. 11-170442).

However, due to the limitation of the dispersion technology, the production cost in the coating increases by coating the IR blocking layer and the adhesive layer composed of metal oxides separately, and the thin film (3 ~ 5m) in the ratio to the thick film (10 ~ 20m). The barrier layer must be applied using a precision coater and the coating workability is disadvantageous. In addition, even if the hard coating layer is applied, there is a problem that the IR blocking performance is reduced due to damage to the coating surface due to wear and scratches, such that the thermal insulation performance is reduced.

In order to solve this problem, a method of manufacturing a transparent functional pressure-sensitive adhesive (Japanese Patent Laid-Open No. 10-8010) has been proposed that simplifies the coating process and improves workability by dispersing nano metal oxide particles in the pressure-sensitive adhesive. However, this method is difficult to secure various adhesion performance and IR blocking performance due to the difficulty in controlling the concentration of the IR blocking agent and the adhesive as the IR blocker is dispersed in the acrylic monomer (monomer) before the adhesive polymerization. Improvement is urgently needed.

The present invention is to provide a pressure-sensitive adhesive that solves the problems of the prior art as described above, and a high transparent heat insulation film coated with the pressure-sensitive adhesive and their manufacturing method.

The main object of the present invention is to provide a high transparency heat-insulating adhesive having high transmittance in visible light and excellent IR blocking performance, a high transparent heat-insulating film coated with the pressure-sensitive adhesive, and a method of manufacturing the same.

The present inventors have conducted a long study to achieve the object of the present invention, by stabilizing the nano-metal oxide particles having IR blocking performance with an alkoxysilane and / or halide silane compound to uniformly dispersed in the adhesive resin The object of the present invention was achieved.

In the pressure-sensitive adhesive containing a metal oxide having ultraviolet ray blocking ability, the high-transparent insulating adhesive according to the present invention, wherein the pressure-sensitive adhesive contains an alkoxysilane-based and / or halide silane-based compound which is a stabilizer of the metal oxide having ultraviolet ray blocking ability. It is characterized by.

The composition of the high-transparent insulating adhesive according to the present invention contains 20 to 150 parts by weight of an IR blocking metal oxide and 10 to 80 parts by weight of an alkoxysilane and / or halide silane compound as stabilizers based on 100 parts by weight of the adhesive resin on a solid content basis. The composition is preferred.

In addition, the high-transparent insulating adhesive film according to the present invention is characterized in that the adhesive layer coated with the adhesive of the present invention is formed on one surface of the transparent base film.

The high-transparent insulating adhesive according to the present invention contains an alkoxysilane and / or halide silane-based compound as a stabilizer of the adhesive resin (or the adhesive material), the metal oxide having ultraviolet ray blocking ability, and the metal oxide having ultraviolet ray blocking performance. do. The pressure-sensitive adhesive base material (or pressure-sensitive adhesive resin) is composed of an acrylic resin and a solvent, and the stabilizer lowers the cohesiveness of the particles to increase the dispersibility of the solvent phase.

The adhesive resin is an acrylic resin, preferably an acrylic copolymer having good transparency and weather resistance and low haze. For example, the same thing as the copolymer resin of 2-ethylhexyl acrylate (2-EHA) and acrylic acid (AA) is preferable. The type of acryl does not have to be considered because it does not significantly affect the dispersion stability of the metal oxide having ultraviolet ray blocking ability, and in the case of a nonpolar solvent, a polar solvent may be added.

The IR blocking metal oxide constituting the highly transparent insulating adhesive according to the present invention is indium tin oxide (ITO), antimony tin oxide (ATO), aluminum zinc oxide (aluminum zinc oxide (AZO), Conventional IR blocking metal oxides such as fluoro tin oxide (FTO), tin oxide (SnO 2), and the like, in which one or two or more of the IR blocking metal oxides are dispersed in a solvent ( sol) to be used. The metal oxide sol according to the present invention is obtained by dispersing an IR blocking metal oxide having a particle size in the range of 10 to 150 nanometers (nm) in an alcohol solvent. The content of the IR blocking metal oxide is preferably 5% by weight or more. When the IR blocking metal oxide concentration of the sol is less than 5%, the concentration of the solid content is too low when mixed with the adhesive resin, so that problems such as productivity and coating property are likely to occur.

The high transparent heat-insulating adhesive of the present invention is prepared by preparing a sol in which a metal oxide having ultraviolet ray blocking ability is dispersed in an alcohol solvent, and a metal oxide sol stabilized by mixing, stirring and reacting the stabilizer and water in the sol. After the preparation, it can be prepared by mixing with a pressure-sensitive adhesive material prepared separately, high speed stirring.

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

Indium tin oxide (ITO) (solid 30%, solvent 2-Methoxyethanol) and antimony tin oxide (ATO) (solid 30%, solvent 2-Methoxyethanol) sol were respectively added to an acrylic adhesive substrate (40% solid, solvent Ethyl Acetate). The mixture was sufficiently stirred and mixed to form a pressure-sensitive adhesive, and the PET transparent substrate was coated with a thickness of 15 microns. However, in order to achieve the present invention, the physical properties of visible light transmittance of 60% or more, IR blocking rate (1000 nm) of 60 or more, and haze of 3.0% or less are required, but the precipitation due to severe aggregation of the metal oxide (ITO and ATO) particles during mixing And a non-uniform film was formed with a haze of 30% or more upon coating.                     

The present inventors examined the method of stabilizing the nano metal oxide in various angles in order to prevent the aggregation and precipitation of the IR-blocking metal oxide as described above.

First, when the nano metal oxide is mixed with the adhesive base (adhesive resin), the stabilization behavior of the particles is investigated to determine the cause of the aggregation phenomenon.The instability of the nano metal oxide is due to the high surface energy. Depending on the size of the local electrostatic charge and the particle size, the local electrostatic charge was found to be different depending on the type of metal. In other words, when the particle size is the same, the nano-size particles of the metal oxide have relatively high surface energy as the partial positive charge of the central metal is relatively large, and thus the pH, solvent, and the like are relatively high. When the surface charge decreases due to the change, the electrostatic repulsive force between the particles supporting the dispersion is weakened, and the reaction proceeds in the direction of decreasing the surface energy, which may be due to the tendency to stabilize with strong aggregation.

The inventors have repeatedly experimented to ensure the stability when the surface energy of the nano metal oxide is dispersed in the acrylic adhesive resin, and as a result, the surface energy of the nano metal oxide particles is stabilized with a compound having a relatively low local static charge. Stabilization was achieved by lowering. That is, when the surface of the nanosized particles of metal oxides having high surface energy due to high local static charges are stabilized with alkoxysilane-based and / or halide silane-based compounds having relatively low local static charges, the surface energy is lowered. It has been found that the dependence of charge on stability is significantly reduced. When the stabilized nano metal oxide sol is mixed with the acrylic adhesive resin, particles are not aggregated, and the visible light transmittance and the IR blocking rate can be controlled, and a high transparent insulating adhesive having a high transparency film characteristic having a haze of less than 3% is obtained. It was confirmed that the present invention was completed.

In the present invention, the stabilizer is an alkoxysilane-based compound (RxSiOR4-x, R = organic, OR = alkoxy group) compound or halide silane-based (RxSiX4-x, R = organic, X = F, Cl, Br, etc. Group), or a mixture of an alkoxysilane compound and a halide silane compound.

Suitable alkoxysilane compounds that can be used in the present invention include alkoxysilane compounds such as epoxy alkoxysilanes, vinyl alkoxysilanes, acrylic alkoxysilanes, phenyl alkoxysilanes, alkyl alkoxysilanes and amino alkoxysilanes. Examples of the halide silane compound include compounds such as epoxy halide silane, vinyl halide silane, acryl halide silane, phenyl halide silane, alkyl halide silane, amino halide silane and the like.

In addition, in order to obtain effective stability when dispersing the nano metal oxide sol according to the present invention in the adhesive resin, the hydroxyl group of the silane through hydrogen bonding or hydrolysis of the surface of the nano metal oxide particles and the alkoxysilane and / or halide silane. The chemical bonding reaction by the dehydration reaction between the metal oxide particles and the surface of the metal oxide particles should proceed effectively. After mixing with the alkoxysilane and the nano metal oxide sol in a state where the water / silane mole ratio is 1 or more, It should be reacted while stirring. This is to induce the reaction of the alkoxide group and / or halide silane-based compound with an alkoxide group and / or halide group with a hydroxyl group, followed by reaction with the surface of the metal particle, and the reaction time varies depending on the organic group of the silane. Minutes to about 3 hours were appropriate. This substitution reaction time greatly affects the stabilization of the metal oxide, and may affect the performance of the coating film during application. When the substitution reaction time is short, aggregation of the metal oxide particles is not secured due to incomplete substitution, and aggregation occurs, and when the substitution reaction time is long, the silane compound itself does not function as a stabilizer due to generation of particles. In another stabilization method, alkoxide silane and / or halide silane alkoxide group and / or halide group are added with water so that the molar ratio of water / silane in alcohol is 1 or more, and the hydrolysis reaction time is about 10 minutes to 2 hours. After replacement with a hydroxyl group, the mixture may be modified by mixing with a nano metal oxide sol. At this time, the reaction time is shortened to about 10 to 90 minutes. In this way, contact between water and metal oxides, which are very sensitive to moisture, can be avoided.

Although the stabilized nano metal oxide sol may be mixed with the acrylic adhesive resin as it is, it is preferable to use the mixture with alcohol for effective coating. The use of an alcohol, which is a polar solvent, helps the dispersion stability by minimizing the reduction of the surface charge when mixing the metal oxide particles with the adhesive resin, and also improves the coating workability by lowering the viscosity when the adhesive is high viscosity. . It is preferable that the addition ratio of alcohol mixes a high transparent heat insulation adhesive and alcohol in the weight ratio of 1: 0-1: 1. In addition, although alcohol mixing may be mixed at any time in the manufacturing process, it is most preferable to add at the time of stabilization of a metal oxide. The alcohol may be selected from one or more of methanol, ethanol, methoxy ethanol, ethoxy ethanol, 1-propanol, 2-propanol, etc. in consideration of miscibility with the IR blocking adhesive and drying speed after coating.

Highly transparent heat-insulating adhesive film according to the present invention is a pressure-sensitive adhesive layer is formed with the pressure-sensitive adhesive of the present invention on one surface of the transparent base film as shown in Figure 2 (a).

The transparent base film constituting the high-transparent insulating adhesive film according to the present invention is not limited as long as it is a synthetic resin film or sheet having excellent transparency such as polyethylene terephthalate (PET), polymethyl methacrylate (PMMA), polycarbonate (PC) and the like. It is possible to use, and the thickness thereof is preferably in the range of 25 to 150 m. The pressure-sensitive adhesive layer formed on one surface of the transparent base film is formed according to a conventional known coating method for the pressure-sensitive adhesive according to the present invention. The thickness of the coated film is not particularly limited. That is, it can be selected in consideration with the desired adhesive properties. In this case, an increase in thickness results in a decrease in visible light and an increase in IR blocking rate, and a decrease in thickness causes opposite property changes.

In the high transparent insulating adhesive film according to the present invention, an adhesive layer may be formed on one surface of the transparent base film, and a hard coating layer may be further formed on the other side of the base film.

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

Example 1

20 g of ITO sol, in which 30 g (g) of indium tin oxide (ITO) was dispersed in 70 g (g) of isopropanol, was mixed with 30 g of methanol, and then stabilized in the mixed solution (50 g). 2 g of methyltrimethoxysilane (MTMS) and 0.5 g of vinyltriethoxysilane (VTES) were added together with 0.2 g of H 2 O, followed by stirring for 1 hour to obtain a stabilized ITO sol. 60 wt% (%) of ethyl acetate and toluene mixed solvent prepared in advance and 40 wt% (%) of acrylic copolymer resin composed of 2-EHA (2-ethylhexyl acrylate) and AA (acrylic acid) After mixing with 40 grams (g) of the substrate, an IR-blocking adhesive was prepared by performing high-speed stirring for about 10 minutes for uniform dispersion of the ITO sol.

The IR blocking adhesive was applied to a 50m-thick PET film with a bar coater at a thickness of 15m, and then measured using a haze meter. As shown in Table 1 below, visible light transmittance of 75% and haze of 2.3% were confirmed. . In addition, the IR blocking rate of the 1000nm near-infrared wavelength band was 74% using UV-VIS-NIR spectroscopy.

Comparative Example 1

20 g of ITO sol and 30 g of methanol were mixed in the same manner as in Example 1 without using the stabilizer MTMS and VTES, and then mixed with 40 g of the adhesive base, followed by high speed stirring for about 10 minutes for uniform dispersion of the ITO sol. To prepare an IR blocking adhesive. However, it could be confirmed visually that precipitation of ITO particles occurred due to severe aggregation.

After applying this pressure-sensitive adhesive on a PET film with a thickness of 15 m, as a result of analysis, a nonuniform film of 66% visible light transmittance and 34% haze was formed as shown in Table 1 below.

Example 2

20 g of ITO sol, in which 30 g (g) of indium tin oxide (ITO) was dispersed in 70 g (g) of 2-Methoxyethanol, 10 g of methanol and 10 g of isopropanol In the mixed solution (40 g), 2 g of methyltrimethoxysilane (MTMS) as a stabilizer, 0.5 g of vinyltriethoxysilane (VTES) and 2 g of 3-Methacryloxypropyltrimethoxysilane (MATMS) were added to 0.3 g of H2O. After addition together, the mixture was stirred and reformed for 1 hour to obtain a stabilized ITO sol. This mixture was mixed with 60 grams (g) of an ethyl acetate and toluene solvent prepared in advance and 40 grams (g) of an acrylic copolymer resin 40% by weight, and then uniform dispersion of the ITO sol was performed. In order to prepare a IR-blocking pressure-sensitive adhesive for about 10 minutes by high speed stirring.

As a result of measuring the physical properties after applying the obtained IR blocking adhesive on PET, as shown in Table 1, the performance of visible light transmittance of 65%, haze 1.4% and IR blocking rate 70% was secured.

Example 3

30 g of ITO sol, in which 30 g of antimony tin oxide (ATO) was dispersed in 70 g of 2-methoxyethanol, isopropanol using 0.4 g of H 2 O. After reacting for 1 hour at 20 g, 3 g of pre-hydrolyzed MTMS and 1 g of VTES were mixed, followed by stirring for 20 minutes to obtain a stabilized ATO sol. This mixture was mixed with 60 grams (g) of an ethyl acetate and toluene solvent prepared in advance and 40 grams (g) of an acrylic copolymer resin 40% by weight, and then uniform dispersion of the ITO sol was performed. In order to prepare a IR-blocking pressure-sensitive adhesive by high-speed stirring for about 10 minutes.

As a result of measuring the physical properties after applying the obtained IR blocking adhesive on PET, as shown in Table 1, the performance of visible light transmittance of 68%, haze 1.1%, and IR blocking rate 64% was secured.

Adhesive (g) ITO (g) ATO (g)  Solvent Stabilizer Use Visible light transmittance (%) Haze (%) IR Cut (1000nm,%) Example 1                                              40 20 Methanol: 30 U 75 2.3 74 Example 2 40 10 20 Methanol: 10 Isopropanol: 10 U 65 1.4 70 Example 3                                              40 30 Isopropanol: 20 U 68 1.1 64 Comparative Example 1                                              40 20 Methanol: 30 radish 66 34.0

As described above, the high-transparent insulating adhesive of the present invention and the high-transparent insulating adhesive film coated therewith have a high transmittance in visible light, a high infrared ray blocking rate, excellent adhesion performance, and a reduction in process cost. The workability of the coating process is greatly improved by introducing the IR blocking layer, which is a thin film, into the pressure-sensitive adhesive layer, which is a thick film.

Claims (8)

100 parts by weight of an adhesive resin; Indium tin oxide (ITO), antimony tin oxide (ATO), aluminum zinc oxide (AZO), fluoro tin oxide (FTO) or tin oxide : 20 to 150 parts by weight of a metal oxide having one or two or more infrared (IR) blocking performance selected from SnO ₂ ); And A high transparent heat-insulating adhesive comprising 10 to 80 parts by weight of an alkoxysilane compound, a halide silane compound, or an alkoxysilane and halide silane compound as a stabilizer of the metal oxide. delete The method of claim 1, wherein the particle size of the metal oxide having the infrared blocking ability is 10 to 150 nanometers (nm), characterized in that the high transparent insulating adhesive. The alkoxysilane-based compound according to claim 1 or 3, wherein the alkoxysilane-based compound as a stabilizer of the metal oxide having infrared (IR) blocking performance is epoxy-alkoxysilane, vinyl-alkoxysilane, acrylic-alkoxysilane, phenyl-alkoxysilane, alkyl. It is an alkoxysilane, or an amino-alkoxysilane, The said halide silane type compound is an epoxy halide silane, a vinyl halide silane, an acryl halide silane, a phenyl halide silane, an alkyl halide silane, or an amino halide silane, It is characterized by the above-mentioned. High transparent insulation adhesive. A pressure-sensitive adhesive film having a pressure-sensitive adhesive layer containing a metal oxide having infrared (IR) blocking performance, wherein the pressure-sensitive adhesive layer is formed of the high transparent heat-insulating pressure-sensitive adhesive according to claim 1 or 3. . The method of claim 5, wherein the high-transparent insulating adhesive film is a high transparent insulating adhesive film, characterized in that composed of an adhesive layer and a release paper on one side of the transparent base film. The high transparent insulating pressure-sensitive adhesive film of claim 6, wherein the high transparent heat insulating adhesive film further comprises a hard coating layer on the base film. The high transparent insulating adhesive film of claim 5, wherein the high transparent insulating adhesive film has a visible light transmittance of 60% or more, an IR blocking rate (1000 nm) of 60 or more, and a haze of 3.0% or less.

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