KR100887869B1 - Multi-layered Plastic Substrate with Excellent Chemical Resistance and Fabrication Method Thereof - Google Patents

Abstract

The present invention relates to a multilayer plastic substrate and a method of manufacturing the same. In particular, a first organic or organic-inorganic hybrid layer on each of the two bonded plastic films; A gas barrier layer and a polysilazane layer stacked on each top surface of the first organic or organic-inorganic hybrid layer and repeatedly stacked one or more times in any order; The present invention relates to a multilayer plastic substrate having a symmetrical structure having improved chemical resistance, including a second organic or organic-inorganic hybrid layer laminated on each upper surface of the gas barrier layer or the polysilazane layer.

The multi-layered plastic substrate according to the present invention not only has a small coefficient of linear expansion, excellent dimensional stability, and excellent gas barrier properties, but also provides a multi-layered plastic substrate having further improved chemical resistance because it uses a crosslinked polysilazane layer.

Plastic substrate, hybrid layer, gas barrier property, dimensional stability, coefficient of linear expansion

Description

Multi-layered Plastic Substrate with Excellent Chemical Resistance and Fabrication Method Thereof}

1 is a cross-sectional view schematically showing a symmetrical structure of a multilayer plastic substrate according to the present invention;

2 to 4 are cross-sectional views illustrating a schematic structure of a multilayer plastic substrate having a symmetrical structure according to an embodiment of the present invention.

* Description of the symbols for the main parts of the drawings *

110: plastic film

115: first organic or organic-inorganic hybrid layer

120: gas barrier layer

125: polysilazane layer

130: second organic or organic-inorganic hybrid layer

The present invention relates to a multi-layered plastic substrate and a method of manufacturing the same, and more particularly, to a multi-layered plastic substrate having a low coefficient of linear expansion, excellent dimensional stability, and excellent gas barrier properties as well as further improved chemical resistance and its manufacture It's about how.

Glass substrates used for display devices, frames, crafts, containers, etc. have many advantages such as small coefficient of linear expansion, excellent gas barrier property, high light transmittance, surface flatness, excellent heat resistance and chemical resistance, but they are fragile and easily broken due to their low impact. There is a heavy disadvantage due to the high.

In recent years, as the interest in liquid crystals, organic light emitting displays, and electronic papers has increased rapidly, studies are being actively conducted to replace the substrates of these display devices from glass to plastic. In other words, replacing the glass substrate with a plastic substrate may reduce the overall weight of the display device and provide design flexibility, and it may be more impact-resistant and economical than the glass substrate when manufactured in a continuous process.

Meanwhile, in order to be used as a plastic substrate of a display device, a process temperature of a transistor element, a high glass transition temperature capable of withstanding the deposition temperature of a transparent electrode, oxygen and water vapor blocking characteristics to prevent aging of liquid crystals and organic light emitting materials, and a process temperature Small coefficient of linear expansion and dimensional stability to prevent warpage of substrates due to changes, high mechanical strength compatible with process equipment used in conventional glass substrates, chemical resistance to etch process, high light transmittance and low birefringence, Properties such as scratch resistance of the surface are required.

However, since there is no high functional polymer base film (including a polymer film and a polymer-inorganic composite film) satisfying all of these conditions, efforts have been made to satisfy the above properties by applying a functional coating of several layers to the polymer base film.

Examples of representative coating layers include organic planarization layers that reduce defects on the surface of polymers and impart flatness, gas barrier layers made of inorganic materials for blocking gases such as oxygen and water vapor, and organic or organic-inorganic hard coating layers for imparting scratch resistance to surfaces. Etc. can be mentioned.

In the case of many conventional multilayer plastic substrates, a process of coating an inorganic gas barrier layer on a polymer substrate and forming a hard coating layer on the gas barrier layer is a problem when manufacturing the multilayer structure is a polymer substrate and a gas barrier layer Deformation of the polymer substrate and cracking of the inorganic thin film due to the large difference in coefficient of linear expansion between them, and peeling may occur. Therefore, it can be said that the adhesion between the coating layer and the design of a suitable multi-layer structure that can minimize the stress at the interface of each layer.

A monomer thin film is formed on a polymer substrate film of Vitex Systems of the United States, polymerized by irradiation with ultraviolet (UV) light and polymerized (solidified organic layer), and an inorganic thin film is formed thereon by sputtering. The process was repeated to prepare several layers of organic-inorganic layers, and a flexible substrate having excellent gas barrier properties.

However, although a product having excellent gas barrier properties can be obtained by the above method, it is not suitable for use of a display requiring a low coefficient of linear expansion, and it does not provide a solution.

US Patent No. 6,465,953 discloses a method for dispersing getter particles that can react with incoming oxygen and water vapor on a plastic substrate in order to use the plastic substrate in an organic light emitting device sensitive to oxygen and water vapor. The size of the getter particles should be sufficiently smaller than the size of the particular wavelength to be emitted, and the dispersion should be evenly distributed so that the emitted light can pass through the substrate without being scattered. In addition, this method was intended to minimize the amount of oxygen and water vapor introduced by coating a gas barrier film made of an inorganic material on the plastic substrate. However, this method is difficult to manufacture a substrate by uniformly dispersing nanoparticles of 100 to 200 nm in size, and the thickness of the plastic substrate must be thick to contain a large amount of getter particles that can react with oxygen and water vapor and the inorganic gas on the plastic substrate. Since the barrier film is directly coated, there is a high possibility that cracks or peeling will occur on the gas barrier film due to temperature changes.

U.S. Patent No. 6,322,860 discloses a crosslinkable composition comprising a silica particle or the like on one side or both sides of a polyglutamide sheet within 1 mm thickness prepared by reaction extrusion (a polyfunctional acrylate monomer or oligomer). , Alkoxysilane, and mixtures thereof), followed by photocuring or thermosetting, to prepare a crosslinked coating film, coating a gas barrier film thereon, and optionally coating the crosslinking coating film on the barrier film to display plastics for display devices. The substrate was manufactured. However, this method is only small enough that the oxygen and water vapor transmission rates can be used for liquid crystal displays in some special cases, and still does not improve on the low linear expansion coefficient and excellent dimensional stability required for use as glass replacement substrates. Did.

US Patent No. 6,503,634 discloses an organic-inorganic hybrid ORMOCER and a silicon oxide layer coated on one polymer substrate or in the middle layer of two polymer substrates, which are 1/30 or less of the polymer substrate before the oxygen permeability coating, and the water vapor transmission rate. The multilayer film which is 1/40 or less of the polymer base material before is shown. However, this method presented a possibility that oxygen, water vapor transmission rate can be significantly reduced compared to the polymer base material before coating, and can be used as a packaging material, but there is no mention of improving the coefficient of linear expansion and dimensional stability.

Accordingly, the present invention provides a multilayer plastic substrate and a method of manufacturing the same, which satisfy both low linear expansion coefficient, excellent dimensional stability, and excellent gas barrier property, and further improve chemical resistance without problems due to the difference in coefficient of linear expansion between layers. The purpose is to.

In order to achieve the above technical problem, the present invention, the first organic or organic-inorganic hybrid layer on each of the two bonded plastic film; A gas barrier layer and a polysilazane layer stacked on each top surface of the first organic or organic-inorganic hybrid layer and repeatedly stacked one or more times in any order; Provided is a symmetrical multilayer plastic substrate comprising a second organic or organic-inorganic hybrid layer laminated on each top surface of the gas barrier layer or polysilazane layer.

In addition, the present invention to achieve the above other technical problem,

(a) coating and curing the composition for forming an organic or organic-inorganic hybrid layer on one side of the plastic film to form a first organic or organic-inorganic hybrid layer;

(b) forming a multi-layer film on the upper surface of the first organic or organic-inorganic hybrid layer by repeating the gas barrier layer and the polysilazane layer at least once in any order;

(c) forming a second organic or organic-inorganic hybrid layer by coating and curing an organic or organic-inorganic hybrid layer-forming composition on the entire upper surface of the multilayer film;

(d) repeating the steps (a) to (c) to prepare one more multilayer film having the same structure as in step (c); And

(e) bonding the surfaces of each of the plastic films on which the layers of each of the multilayer films prepared in steps (c) and (d) are not formed to each other to form a symmetrical structure;

It provides a method of manufacturing a multilayer plastic substrate having improved chemical resistance comprising a.

Hereinafter, the present invention will be described in detail.

The multilayer plastic substrate of the present invention has improved chemical resistance, comprising: a first organic or organic-inorganic hybrid layer centered on two bonded plastic films; A gas barrier layer and a polysilazane layer that are repeatedly stacked at least once in any order; Second organic or organic-inorganic hybrid layers are sequentially stacked to have a symmetrical multilayer structure.

The present invention is to position the organic or organic-inorganic hybrid layer between the plastic film and the multilayer film formed by repeatedly laminating the gas barrier layer and the polysilazane layer one or more times in any order. Positioned on the upper front of the multilayer film, respectively, to minimize the difference in the inter-layer coefficient of expansion and improve the adhesion between the layers.

The plastic film may be used by selecting one or more from the group consisting of a single polymer, two or more polymer blends, and a polymer composite material containing an organic or inorganic additive.

As a preferable example of the polymer, when the plastic substrate of the present invention is used as a substrate of the liquid crystal display device, since the manufacturing process for forming the thin film transistor and the transparent electrode is performed at a high temperature of 200 ° C or higher, high heat resistance that can withstand such high temperature A polymer having is required. Examples of the polymer having the above-mentioned properties include polynorbornene, aromatic florene polyester, polyethersulfone, bisphenol A polysulfone, polyimide and the like. In addition, as the recent research on lowering the temperature of high temperature substrate process is progressing, polymers such as polyethylene terephthalate, polyethylene naphthalene, polyarylate, polycarbonate, and cyclic olefin copolymer which can be used up to a temperature of around 150 ° C can be used. have.

In addition, as the plastic film, a nanomaterial is dispersed in a polymer, and a polymer composite material containing an organic or inorganic additive may be used.

The polymer composite material may include a polymer-clay nanocomposite in which clay nanomaterials are dispersed in a polymer matrix. The polymer-clay nanocomposite has a smaller amount of clay than a conventional composite such as glass fiber due to the small particle size (<1 μm) and the large aspect ratio of the clay. And physical properties such as dimensional stability can be improved. That is, in order to improve the above properties, it is important to peel off the clay layer having a layered structure and disperse it well in the polymer matrix, and to satisfy this, the polymer-clay nanocomposite is satisfied.

Polymers that can be used in the polymer-clay nanocomposite include polystyrene, polymethacrylate, polyethylene terephthalate, polyethylene naphthalene, polyarylate, polycarbonate, cyclic olefin copolymer, polynorbornene, aromatic florene polyester, Polyether sulfone, polyimide, epoxy resin, polyfunctional acrylate, and the like, and as the clay, laponite, montmorillonite, megadite and the like can be used.

The plastic film is preferably in the form of a film or sheet having a thickness of 10 to 2,000 ㎛.

In the multi-layered plastic substrate of the present invention, the first organic or organic-inorganic hybrid layer is a plastic material by mitigating the difference in the large coefficient of linear expansion between the plastic film and the gas barrier layer or the polysilazane layer and appropriately adjusting the composition of the organic and inorganic materials. It serves to improve the adhesion between the film and the gas barrier layer. In addition, the first organic or organic-inorganic hybrid layer may planarize the surface of the plastic film to minimize defects formed during deposition of the gas barrier layer.

In the multilayer plastic substrate of the present invention, the second organic or organic-inorganic hybrid layer not only serves as a protective layer to prevent cracking of the gas barrier layer or the polysilazane layer, but also bridges the defect of the gas barrier layer. It serves to further improve gas barrier properties. In addition, it may also play a role in achieving low resistance due to the excellent planarization function in the formation of the transparent conductive film.

In this case, the first and second organic or organic-inorganic hybrid layer is a monomer of an organic compound having two or more polymerizable unsaturated groups in a molecule, or a weight average molecular weight of 100 or more having 1,000 or more polymerizable unsaturated groups in a molecule The following oligomers; And a coating composition containing an organic compound having a weight average molecular weight of 1,000 or more and 500,000 or less having one or more polymerizable unsaturated groups in the molecule, and cured by using UV curing alone or in combination with a thermosetting method.

In addition, the first and second organic or organic-inorganic hybrid layer,

(A) an organosilane partial hydrolyzate selected from the group consisting of compounds represented by the following formulas (1) to (3); And / or (B) at least one metal alkoxide partial hydrolyzate selected from the group consisting of compounds represented by the following formula (4) may be formed by curing by using UV curing alone or in combination with a thermosetting method.

(R ¹ ) _m -Si-X _(4-m)

(R ¹ ) _m -O-Si-X _(4-m)

(R ¹ ) _m -N (R ² ) -Si-X _(4-m)

M- (R ³ ) _z

In Chemical Formulas 1 to 3,

X may be the same or different from each other, hydrogen, halogen, alkoxy, acyloxy, alkylcarbonyl, alkoxycarbonyl, or -N (R ² ) ₂ having 1 to 12 carbon atoms,

R ¹ may be the same or different from each other, alkyl, alkenyl, alkynyl, aryl, arylalkyl, alkylaryl, arylalkenyl, alkenylaryl, arylalkynyl, alkynylaryl, halogen, amide having 1 to 12 carbon atoms , Aldehydes, ketones, alkylcarbonyl, carboxy, mercapto, cyano, hydroxy, alkoxycarbon having 1 to 12 carbon atoms, alkoxycarbonyl having 1 to 12 carbon atoms, sulfonic acid, phosphoric acid, acryloxy, methacrylicoxy, epoxy, Or vinyl group,

R ² is hydrogen or alkyl having 1 to 12 carbon atoms,

m is an integer of 1 to 3,

In Chemical Formula 4,

M represents a metal selected from the group consisting of aluminum, zirconium, and titanium,

R ³ may be the same as or different from each other, and is a halogen, an alkyl, alkoxy, acyloxy, or hydroxy group having 1 to 12 carbon atoms,

Z is an integer of 3 or 4.

Each of the first organic or organic-inorganic hybrid layer and the second organic or organic-inorganic hybrid layer may have a thickness of 0.1 to 50 μm, 0.1 to 20 μm, and 0.1 to 10 μm. It is preferable that it is micrometer. In the above range, the obstacle due to the pinhole defect may be easily overcome, and surface irregularities may be easily formed.

In the multilayer plastic substrate of the present invention, the gas barrier layer can block gases such as oxygen and water vapor, and is preferably a high density inorganic layer having a small coefficient of linear expansion.

The gas barrier layer is, for example, a group consisting of SiO _x (where x is an integer of 1 to 4), SiO _x N _y (where x and y are each an integer of 1 to 3), Al ₂ O ₃ , and ITO It is preferred that it is formed from one or more inorganic substances selected from.

In this case, the thickness of the gas barrier layer may be 5 to 1,000 nm or 10 to 500 nm, most preferably 20 to 300 nm. In the above-described range, the dispersed state of the layered scatterer including silicon oxide is sufficient, homogeneity of the gas barrier layer can be ensured, and the occurrence of gas barrier properties and cracks during handling can be prevented.

In the multilayer plastic substrate of the present invention, the polysilazane layer may include perhydropolysilazane represented by Chemical Formula 5; And at least one of an organopolysilazane represented by Formula 6 and an organopolysilazane represented by Formula 7.

In Formula 5, n is a positive integer.

In Formula 6, n is a positive integer, R ⁴ , R ⁵ , and R ⁶ is hydrogen, alkyl of 1 to 12 carbon atoms, alkoxy of 1 to 12 carbon atoms, alkylsilyl of 1 to 12 carbon atoms, of 1 to 12 carbon atoms Alkylamino, cycloalkyl having 1 to 12 carbon atoms, alkenyl having 1 to 12 carbon atoms, and allyl having 1 to 12 carbon atoms.

In Formula 7, n and m are positive integers, R is alkyl having 1 to 12 carbon atoms.

The polysilazane layer preferably has a thickness of 5 to 1,000 nm. When the thickness is thinner than 5 nm, high scratch resistance is hardly obtained, and when the thickness is thicker than 1,000 nm, there is a problem of curling of the substrate due to shrinkage of the coating layer.

Hereinafter, a method of manufacturing the multilayer plastic substrate of the present invention will be described in detail as follows, but the scope of the present invention is not limited thereto.

First, a plastic film is prepared.

In the multilayer plastic substrate of the present invention, the plastic film is preferably in the form of a film or sheet having a thickness of 10 to 2,000 m.

The plastic film may be manufactured through a solution casting method or a film extrusion process, and may be briefly annealed for a few seconds to several minutes in the vicinity of the glass transition temperature in order to minimize deformation due to temperature after the manufacture. After annealing, primer coating may be applied to the surface of the plastic film to improve the coating property and adhesion, or the surface may be treated by plasma treatment using corona, oxygen or carbon dioxide, ultraviolet-ozone treatment, ion beam treatment with a reaction gas, or the like. have.

In step (a), one side of the plastic film is coated with a composition for forming an organic or organic-inorganic hybrid layer and cured to form a first organic or organic-inorganic hybrid layer.

The organic or organic-inorganic hybrid layer may be prepared from at least one compound selected from the group consisting of the coating composition described above, (A) the organosilane partial hydrolyzate, and / or (B) metal alkoxide partial hydrolyzate. In this case, a filler and a solvent may be additionally added to the compound.

The fillers are metal, glass powder, diamond powder, silicon oxide, clay, calcium phosphate, magnesium phosphate, barium sulfate, aluminum fluoride, calcium silicate, magnesium silicate, barium silicate, barium carbonate, barium hydroxide, and aluminum silicate. It can select and use 1 or more types from the group which consists of.

The solvent may be used a solvent used for a conventional partial hydrolysis reaction, preferably distilled water may be used. In addition, a catalyst may also be used, although not particularly limited, preferably aluminum butoxide and zirconium propoxide.

The amount of the filler, the solvent, and the catalyst used is not particularly limited as it is added as needed.

In the present invention, the flatness of roughness (Ra) of the surface of the first organic or organic-inorganic hybrid layer is very important. If the layer is not flat, defects occur when the barrier layer is deposited, and thus barrier property does not come out. Results. Therefore, the lower the flatness value, the higher the barrier property.

In the present invention, the surface flatness of the first organic or organic-inorganic hybrid layer is preferably about 1 nm, more preferably 1 nm or less. Specifically, the flatness may have a Ra value of 0.1 to 1.2.

In step (b), the gas barrier layer and the polysilazane layer on which the inorganic material is deposited are repeated on the upper surface of the first organic or organic-inorganic hybrid layer prepared in step (a) one or more times in any order. Form a film.

When the gas barrier layer, which is an inorganic material layer that may be formed on the first organic or organic-inorganic hybrid layer prepared in step (a), is laminated, the adhesion between the inorganic material layer and the organic or organic-inorganic hybrid layer is excellent. The gas barrier properties are improved by the inorganic layer, and the mechanical properties of the entire substrate can also be improved because the modulus of the inorganic layer itself is high and the coefficient of linear expansion is small.

The method of forming the gas barrier layer is because the oxygen permeability and the water vapor permeability of the plastic film itself usually have a value of several tens to thousands of units. Chemical vapor deposition may be used to block oxygen and water vapor by coating.

In this case, in the case of a transparent inorganic oxide thin film, if a defect such as a pinhole or crack is present, it is difficult to obtain sufficient oxygen and water vapor blocking effects, and in the case of a thin metal thin film, it is difficult to obtain a uniform thin film having a few nanometers thickness without defects. The light transmittance in the visible light region is difficult to exceed 80%. For this reason, the thickness of the gas barrier layer formed through the above method is preferably 5 to 1,000 nm, preferably 10 to 500 nm, more preferably 20 to 300 nm.

The inorganic material may be one selected from the group consisting of SiO _x (where x is an integer of 1 to 4), SiO _x N _y (where x and y are each an integer of 1 to 3), Al ₂ O ₃ , and ITO The metal oxide or metal nitride selected above can be used.

As the deposition coating method, a sputtering method, a chemical vapor deposition method, an ion plating method, a plasma chemical vapor deposition method, a sol-gel method, or the like can be used.

The polysilazane layer which may be formed on the barrier layer may include perhydropolysilazane represented by Chemical Formula 5 as described above; And it may be formed by crosslinking the organopolysilazane represented by the formula (6) or (7).

The polysilazane layer is preferably, at a temperature of 300 ° C. or less and a relative humidity of 50% or less with respect to the composition in which the perhydropolysilazane and the organopolysilazane are blended in a weight ratio of 100/0 to 50/50. It is formed by crosslinking. In addition to forming a dense layer in the above-described range, it is possible to form a coating layer that contributes to planarization. In this case, plasma treatment using oxygen may be additionally performed at atmospheric pressure or lower.

As a catalyst for promoting the crosslinking reaction of the polysilazane layer, 1-methylpiperazine, 1-methylpiperidine, 4,4'-trimethylenedipiperidine, 4,4'-trimethylenebis (1-methyl Piperidine), diazabicyclo- [2,2,2] octane, cis-2-6-dimethylpiperazine, 4- (4-methylpiperizine) pyridine, pyridine, dipyridine, α-picoline, β -Picoline, γ-picoline, piperidine, lutidine, pyrimidine, pyridazine, 4,4'-trimethylenedipyridine, 2- (methylamino) pyridine, pyrazine, quinoline, quinoxaline, triazine, N-heterocyclic compounds of pyrrole, 3-pyrroline, imidazole, triazole, or 1-methylpyrrolidine; Methylamine, dimethylamine, trimethylamine, ethylamine, diethylamine, triethylamine, propylamine, dipropylamine, diheptylamine, octylamine, dioctylamine, trioctylamine, phenylamine, diphenylamine, or Amines of triphenylamine; 1,8-diazabicyclo [5,4,0] 7-undecene, 1,5-diazabicyclo [4,3,0] 5-nonene, 1,5,9-triazacyclododecane, and It can be used by selecting one or more from the group consisting of 1,4,7-triazacyclononane, the amount of use is in the range that does not substantially impair the properties of the product, blended in 0.5 to 10 parts by weight relative to the polysilazane It is preferable to use.

As described above, the polysilazane layer preferably has a thickness of 5 to 1,000 nm. When the thickness is thinner than 5 nm, high scratch resistance is hardly obtained, and when the thickness is thicker than 1,000 nm, curling of the substrate due to volume shrinkage of the coating layer occurs.

In step (c), the organic or organic-inorganic hybrid layer-forming composition is coated and cured on the upper surface of the multilayer film prepared in step (b) to form a second organic or organic-inorganic hybrid layer.

The second organic or organic-inorganic hybrid layer formed on the multilayer film composed of the gas barrier layer prepared in step (b) and the polysilazane layer is used on the surface to minimize the possibility of cracking in the multilayer film. To impart chemical resistance and scratch resistance to the multilayer plastic film.

In addition, in the present invention, a hydration reaction occurs between the hydroxyl group of the inorganic layer and the hydroxyl group of the organic or organic-inorganic hybrid layer at a defective portion such as pinholes or cracks that may be present in the inorganic layer to heal the defect of the inorganic layer, thereby preventing the gas barrier. The sex can be further improved.

The composition of the second organic or organic-inorganic hybrid layer laminated on the gas barrier layer (inorganic layer) or polysilazane layer is the same as the composition of the first organic or organic-inorganic hybrid layer coated on the plastic film, but the coating The composition and organosilane, the metal alkoxide, and the proportion of the filler and the thickness to be coated may vary depending on the case.

The method of forming the second organic or organic-inorganic hybrid layer may be performed by spin coating, roll coating, bar coating, dip coating, sol solution in the same manner as the method of forming the first organic or organic-inorganic hybrid layer. Coating on the polymer film by a method such as gravure coating, spray coating, and can be prepared by curing by thermal curing, UV curing, infrared curing, high frequency heat treatment method, the thickness after curing is 0.1 to 50㎛, preferably 0.1 to 10 Μm, more preferably 1 to 10 µm. It is excellent in chemical resistance and scratch resistance in the above range, it can fully serve as a protective layer to prevent cracking of the gas barrier layer or polysilazane layer.

The flatness of the second organic or organic-inorganic hybrid layer is also very important in the present invention, since devices such as ITO used in the LCD process or the OLED process are deposited directly on the second organic-inorganic hybrid layer. If the degree is high, the current is concentrated and cannot function properly. Current trends require better flatness in OLEDs, the next generation of displays rather than LCDs.

Therefore, in the present invention, the surface flatness of the second organic-inorganic hybrid layer is also about 1 nm, and more preferably within 1 nm, so as to satisfy such conditions. Specifically, the flatness may have a Ra value of 0.1 to 1.2.

In step (d), in order to manufacture a multilayer plastic substrate having a symmetrical structure, the above steps (a) to (c) are repeated to produce one more multilayer film having the same structure as in step (c).

In step (e), the surfaces of the respective plastic film on which the layers of each of the multilayer films prepared in steps (c) and (d) are not formed are bonded to each other to form a symmetrical structure.

Bonding between the multi-layered plastic film not coated on one side may be made by an acrylic adhesive or a thermal bonding method that is usually used as an adhesive, but is not necessarily limited thereto. At this time, when the adhesive is used, the content is not particularly limited, but the thickness of the formed adhesive layer is greater than 0 and 50 µm or less, preferably 0 and 10 µm or less, and more preferably 0 and 5 µm or less.

As described above, the plastic substrate of the multi-layered structure of the present invention has a very small linear expansion coefficient of 6.5 ppm / K, an oxygen transmission rate of less than 0.05 cc / m 2 / day / atm, and a water vapor transmission rate of less than 0.005 g / m 2 / day. It has excellent gas barrier property and excellent dimensional stability. Therefore, the multi-layered plastic substrate of the present invention can replace the fragile and heavy glass substrate that has been mainly used in conventional display devices, etc., and can also be used as a material requiring excellent gas barrier properties.

Hereinafter, the present invention will be described in more detail by the following examples. However, the following examples presented to aid the understanding of the present invention are merely to illustrate the best preferred embodiments of the present invention, and the scope of the present invention is not limited to the following examples, of course.

< Example  1>

A 100 μm thick PET (Polyethyleneterephthalate, SH38, SK) film prepared by coating a double-sided acrylic primer by a biaxial stretching extrusion process was heat treated in a convection oven at 150 ° C. for 1 minute to remove residual stress, and then used as a plastic film.

Initiators for forming the organic or organic-inorganic hybrid layer 115 include 32.5 parts by weight of tetraethoxysilane, 64.0 parts by weight of glycidyloxypropyltrimethoxysilane, and aminopropyltrimethoxysilane, based on the total composition. 0.5 part by weight, 2.0 parts by weight of aluminum butoxide, and 1.0 part by weight of zirconium propoxide were used, and 80.0 parts by weight of distilled water was added thereto to partially hydrolyze at 25 ° C. for 24 hours to prepare a sol coating composition. The composition was bar-coated on one side of PET, and the solvent was dried at 50 ° C. for 3 minutes, followed by gel reaction for 20 minutes in a convection oven at 125 ° C. The thickness of the organic or organic-inorganic hybrid layer measured by alpha stepper after the gel reaction was 1 μm.

40 sccm of Ar gas and 10 sccm of O ₂ gas are injected onto the organic or organic-inorganic hybrid layer 115 of the gel reaction using Atec Systems' DC / RF magnetron sputter, and 1000 Watt of RF is applied under a pressure of 5 mtorr. A silicon oxide (SiOx, integer of x = 1.8) thin film 120 was deposited as a gas barrier layer by vapor deposition at (13.56 MHz) power for 7 minutes. The thickness of the silicon oxide film 120 observed by SEM was 20 nm.

A coating liquid mixed with a perhydropolysilazane dissolved in xylene at 20% by weight and 0.15% by weight of 4,4'-trimethylenebis (1-methylpiperidine) as a catalyst on the deposited silicon oxide thin film 120. After bar coating and drying the solvent at 50 ° C. for 3 minutes, the cross-linking reaction was carried out at 125 ° C. for 20 minutes in a constant temperature and humidity chamber of 90% relative humidity, and then the surface was subjected to oxygen plasma treatment. After completion of the crosslinking reaction, the thickness of the polysilazane layer 125 measured by alpha stepper was approximately 1 μm.

In order to form the second organic or organic-inorganic hybrid layer 130 on the polysilazane layer 125, the coating composition prepared above was bar-coated, and the solvent was dried at 50 ° C. for 3 minutes, followed by 20 ° C in a convection oven at 125 ° C. The gel reaction proceeded for a minute. The thickness of the organic-inorganic hybrid layer measured by alpha stepper after the gel reaction was 1 μm.

The above process was repeated to produce one more multilayer plastic film as described above. One side of the uncoated plastic was laminated and thermally bonded to prepare a multilayer plastic substrate having a symmetrical structure as shown in FIG. 2.

< Example  2>

In manufacturing the multi-layered plastic substrate in the same manner as in Example 1, except that the polysilazane layer 125 and the gas barrier layer 120 are stacked in the same manner as in Example 1, in FIG. A multilayer plastic substrate having a symmetrical structure as described above was manufactured.

< Example  3>

In fabricating a multilayer plastic substrate in the same manner as in Example 1, except that the inorganic thin film gas barrier layer was sequentially repeated two times after the polysilazane layer was formed, in the same manner as in Example 1. As a result, a multilayer plastic substrate having a symmetrical structure as shown in FIG. 4 was produced.

<Comparison Example  1>

The multilayer plastic substrate was formed in the same manner as in Example 1, except that the polysilazane layer was formed by crosslinking only perhydropolysilazane dissolved in xylene at 20 wt% on the silicon oxide thin film 120 deposited in Example 1. Was prepared.

< Experimental Example >

About the multilayer plastic substrate produced by Examples 1-3 and Comparative Example 1, the light transmittance, haze, and gas transmittance which are main required physical properties as a board | substrate for display apparatuses were measured. The measurement method of each physical property is as follows and applied to all the same examples.

1) Light transmittance: Based on ASTM D1003, each was measured in the visible light range of 380 to 780 nm using a Varian UV-spectrometry.

2) Haze: Hazemeter TC-H3DPK of Tokyo Denshoku was measured by the method of ASTM D1003.

3) Oxygen Permeability: Using OX-TRAN 2/20 of MOCON, measured by relative humidity of 0% at room temperature by the method of ASTM D 3985.

4) Water vapor transmission rate: Using a PERMATRAN-W-3 / 33 was measured for 48 hours at room temperature with a relative humidity of 100% by the method of ASTM F 1249.

5) Pencil hardness: measured by the method of ASTM D3363 under a load of 200 g.

6) Chemical resistance: Excellent when the plastic substrate prepared in the stripper solution used in the liquid crystal display device manufacturing process is immersed at 80 ° C. for 30 minutes, and re-evaluated the properties of the above 1) to 5) and the deviation is within 1%. Indicated as.

All properties described are averaged for at least five measurements so that they can be statistically representative. The experimental results are shown in Table 1 below.

For reference, the oxygen and water vapor transmission rates of the PET film itself used in Example 1 were 25 cc / m 2 / day / atm and 4.5 g / m 2 / day, respectively, and the coefficient of linear expansion was 22.4 ppm / K.

division Oxygen transmittance (cc / ㎡ / day / atm) Water vapor transmission rate (g / ㎡ / day) Light transmittance (400nm) Haze (%) Pencil hardness Chemical resistance Example 1 <0.05 below measuring range <0.005 Below instrument measuring range > 85% <0.3 > 1H Great Example 2 <0.05 below measuring range <0.005 Below instrument measuring range > 85% <0.3 > 1H Great Example 3 <0.05 below measuring range <0.005 Below instrument measuring range > 85% <0.3 > 1H Great Comparative Example 1 <0.05 below measuring range <0.005 Below instrument measuring range > 85% <0.3 > 1H Somewhat good

As shown in Table 1, the substrate of Comparative Example 1 was similar to Examples 1 to 3 in gas barrier properties, surface hardness, etc., but it was confirmed that the chemical resistance was somewhat inferior.

As described above, the multilayer plastic substrate of the present invention not only satisfies the characteristics of small linear expansion coefficient, excellent gas barrier property and dimensional stability at the same time, but also has more improved chemical resistance than the conventional substrate. In addition, the multilayer plastic substrate of the present invention may be used instead of the glass substrate as a plastic substrate for an image display device including a liquid crystal display device, and may also be usefully used as a material for packaging and containers requiring gas barrier properties.

Claims (20)

A first organic or organic-inorganic hybrid layer on each of the two bonded plastic films; A gas barrier layer laminated on each upper surface of the first organic or organic-inorganic hybrid layer, and repeatedly stacked one or more times regardless of the order, and a polysilazane layer having a thickness of 5 to 1,000 nm; And a second organic or organic-inorganic hybrid layer laminated on each top surface of the gas barrier layer or the polysilazane layer. The multilayer plastic substrate of claim 1, wherein the plastic film is selected from the group consisting of a single polymer, at least one polymer blend, and a polymer composite material containing organic or inorganic additives. The method of claim 2, wherein the polymer for the single polymer or the polymer blend is polynorbornene, aromatic florene polyester, polyethersulfone, bisphenolA polysulfone, polyimide, polyethylene terephthalate, polyethylene naphthalene, polyarylate, poly At least one selected from the group consisting of carbonates and cyclic olefin copolymers. The multilayer plastic substrate of claim 2, wherein the polymer composite material containing the inorganic additive is a polymer-clay nanocomposite in which clay nanomaterials are dispersed in a polymer matrix. The method of claim 4, wherein the polymer used in the polymer composite material is polystyrene, polymethacrylate, polyethylene terephthalate, polyethylene naphthalene, polyarylate, polycarbonate, cyclic olefin copolymer, polynorbornene, aromatic florene poly At least one selected from the group consisting of esters, polyethersulfones, polyimides, epoxy resins, and polyfunctional acrylates, wherein the clay is at least one selected from the group consisting of laponite, montmorillonite, and megadite. The organic or organic-inorganic hybrid layer according to any one of claims 1 to 5 has a monomer of an organic compound having two or more polymerizable unsaturated groups in a molecule, or two or more polymerizable unsaturated groups in a molecule. An oligomer having a weight average molecular weight of 100 or more and 1,000 or less; And a coating composition containing a weight average molecular weight of 1,000 or more and 500,000 or less of an organic compound having one or more polymerizable unsaturated groups in a molecule thereof. The method of claim 6, wherein the organic or organic-inorganic hybrid layer is a metal, glass powder, diamond powder, silicon oxide, clay, calcium phosphate, magnesium phosphate, barium sulfate, aluminum fluoride, calcium silicate, magnesium silicate, barium silicate, At least one filler selected from the group consisting of barium carbonate, barium hydroxide, and aluminum silicate; And a solvent further comprising a composition. The method of claim 1, wherein the organic or organic-inorganic hybrid layer, (A) an organosilane partial hydrolyzate selected from the group consisting of compounds represented by the following formulas (1) to (3); Or (B) a multilayer plastic substrate formed by curing at least one metal alkoxide partial hydrolyzate selected from the group consisting of compounds represented by the following formula (4), [Formula 1] (R ¹ ) _m -Si-X _(4-m) [Formula 2] (R ¹ ) _m -O-Si-X _(4-m) [Formula 3] (R ¹ ) _m -N (R ² ) -Si-X _(4-m) [Formula 4] M- (R ³ ) _z In Chemical Formulas 1 to 3, X may be the same or different from each other, hydrogen, halogen, alkoxy, acyloxy, alkylcarbonyl, alkoxycarbonyl, or -N (R ² ) ₂ having 1 to 12 carbon atoms, R ¹ may be the same or different from each other, alkyl, alkenyl, alkynyl, aryl, arylalkyl, alkylaryl, arylalkenyl, alkenylaryl, arylalkynyl, alkynylaryl, halogen, amide having 1 to 12 carbon atoms , Aldehydes, ketones, alkylcarbonyl, carboxy, mercapto, cyano, hydroxy, alkoxycarbon having 1 to 12 carbon atoms, alkoxycarbonyl having 1 to 12 carbon atoms, sulfonic acid, phosphoric acid, acryloxy, methacrylicoxy, epoxy, Or vinyl group, R ² is hydrogen or alkyl having 1 to 12 carbon atoms, m is an integer of 1 to 3, In Chemical Formula 4, M represents a metal selected from the group consisting of aluminum, zirconium, and titanium, R ³ may be the same as or different from each other, and is a halogen, an alkyl, alkoxy, acyloxy, or hydroxy group having 1 to 12 carbon atoms, Z is an integer of 3 or 4. The method of claim 8, wherein the organic or organic-inorganic hybrid layer is a metal, glass powder, diamond powder, silicon oxide, clay, calcium phosphate, magnesium phosphate, barium sulfate, aluminum fluoride, calcium silicate, magnesium silicate, barium silicate, At least one filler selected from the group consisting of barium carbonate, barium hydroxide, and aluminum silicate; And a solvent further comprising a composition. The multilayer plastic substrate of claim 6, wherein each of the first organic or organic-inorganic hybrid layer and the second organic or organic-inorganic hybrid layer has a thickness of 0.1 to 50 μm. The method of claim 6, wherein the gas barrier layer comprises SiO _x (where x is an integer of 1 to 4), SiO _x N _y (where x and y are integers of 1 to 3, respectively), Al ₂ O ₃ , and A multilayer plastic substrate formed from at least one inorganic material selected from the group consisting of ITO. The multilayer plastic substrate of claim 6, wherein the gas barrier layer has a thickness of 5 to 1,000 nm. The method according to any one of claims 1 to 5 and 8 to 9, wherein the polysilazane layer is a perhydropolysilazane represented by the following formula (5); And a multilayer plastic substrate formed by crosslinking at least one of an organopolysilazane represented by Chemical Formula 6 and an organopolysilazane represented by Chemical Formula 7, [Formula 5]

[Formula 6]

[Formula 7]

In Formula 5, n is a positive integer; In Formula 6, n is a positive integer, R ⁴ , R ⁵ , and R ⁶ is hydrogen, alkyl of 1 to 12 carbon atoms, alkoxy of 1 to 12 carbon atoms, alkylsilyl of 1 to 12 carbon atoms, of 1 to 12 carbon atoms Alkylamino, cycloalkyl having 1 to 12 carbon atoms, alkenyl having 1 to 12 carbon atoms, and allyl having 1 to 12 carbon atoms; In Formula 7, n and m are positive integers, R is alkyl having 1 to 12 carbon atoms. The method according to claim 13, wherein as a catalyst for promoting crosslinking reaction of the perhydropolysilazane or organopolysilazane, 1-methylpiperazine, 1-methylpiperidine, 4,4'-trimethylenedipiperidine , 4,4'-trimethylenebis (1-methylpiperidine), diazabicyclo- [2,2,2] octane, cis-2-6-dimethylpiperazine, 4- (4-methylpiperidin) Pyridine, pyridine, dipyridine, α-picolin, β-picolin, γ-picolin, piperidine, lutidine, pyrimidine, pyridazine, 4,4'-trimethylenedipyridine, 2- (methylamino N-heterocyclic compounds of pyridine, pyrazine, quinoline, quinoxaline, triazine, pyrrole, 3-pyrroline, imidazole, triazole, or 1-methylpyrrolidine; Methylamine, dimethylamine, trimethylamine, ethylamine, diethylamine, triethylamine, propylamine, dipropylamine, diheptylamine, octylamine, dioctylamine, trioctylamine, phenylamine, diphenylamine, or Amines of triphenylamine; 1,8-diazabicyclo [5,4,0] 7-undecene, 1,5-diazabicyclo [4,3,0] 5-nonene, 1,5,9-triazacyclododecane, and A multilayer plastic substrate, wherein at least one selected from the group consisting of 1,4,7-triazacyclononane is used. delete (a) coating and curing the composition for forming an organic or organic-inorganic hybrid layer on one side of the plastic film to form a first organic or organic-inorganic hybrid layer; (b) forming a multi-layer film on the upper surface of the first organic or organic-inorganic hybrid layer by repeating a gas barrier layer and a polysilazane layer having a thickness of 5 to 1,000 nm one or more times in any order; (c) coating and curing an organic or organic-inorganic hybrid layer-forming composition on the upper surface of the multilayer film to form a second organic or organic-inorganic hybrid layer; (d) repeating the steps (a) to (c) to prepare one more multilayer film having the same structure as in step (c); And (e) bonding the surfaces of each of the plastic films on which the layers of each of the multilayer films prepared in steps (c) and (d) are not formed to each other to form a symmetrical structure; Method for producing a multilayer plastic substrate comprising a. The method of claim 16, wherein the bonding in the step (e) is made by an acrylic adhesive or a thermal bonding method. An image display apparatus comprising the multilayer plastic substrate according to any one of claims 1 to 5 and 8 to 9. An image display device comprising the multilayer plastic substrate according to claim 6. An image display device provided with the multilayer plastic substrate according to claim 13.

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