KR101575440B1 - Composition for forming resin layer and flexible display substrate using the same - Google Patents

Abstract

The present invention relates to a composition for forming a resin layer, a flexible display substrate using the same, and a manufacturing method thereof. When a flexible display substrate is manufactured using the composition for forming a resin layer of the present invention, it is possible to replace the glass used in the past, to have excellent moldability, to have a transparent and flexible property, and to exhibit heat resistance, thermal expansion, It has an advantage that a superior flexible display substrate can be manufactured.

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a composition for forming a resin layer and a flexible display substrate using the composition.

The present invention relates to a composition for forming a resin layer, a flexible display substrate using the composition, and a method of manufacturing the flexible display substrate.

2. Description of the Related Art Recently, a plasma display panel (PDP), a liquid crystal display (LCD), an organic EL (Organic Light Emitting Diodes) OLED, and the like have been used as a display method in a conventional CRT (Cathode Ray Tube) . In particular, researches are being actively conducted in order to realize such a flat panel display as a flexible display in the future.

On the other hand, plastic substrate material is a key material for realizing plastic flat panel displays (for replacing glass substrates of conventional FPDs) or next generation displays, and is a material that is created by the development of the flexible display industry. Comparing the physical properties of plastic substrate materials for flexible display with those of existing organic substrate materials, it is expected that the key features of flexible displays such as weight, deformability, nonbreakability, design, - Roll-to-roll The plastic material is superior in terms of fairness. However, in order to use a plastic optical film for a substrate, it is required to improve the physical properties in view of the weak chemical resistance, thermal properties, and gas barrier properties of the plastic substrate compared to glass

For this purpose, a method of impregnating a glass fiber sheet with a resin has been proposed. However, the conventional film-impregnating composition has a problem in that it is difficult to apply to acrylic resin and epoxy resin compositions because it has a low heat resistance and is difficult to apply to a high temperature process, and the film is brittle and difficult to apply to a flexible display substrate.

In order to solve the problems of the prior art as described above, the present invention provides a composition for forming a resin layer in which a silicone based binder is mixed with an acrylic monomer or an epoxy resin, and a substrate having improved flexibility and heat resistance using the same, .

In order to achieve the above object, the present invention provides a silicone-based binder having a structure represented by the following formula (1):

At least one compound selected from the group consisting of an acrylic monomer and an epoxy resin; And

There is provided a composition for forming a resin layer comprising an initiator.

[Chemical Formula 1]

In Formula 1, R ₁ to R ₄ may be the same or different from each other, independently represent a C ₁ to C ₁₂ alkyl group, C ₂ to the aryl group of C _12, C ₂ to C ₁₂ aralkyl, or C ₂ to the an alkenyl group of C _12, R ₅ and R ₆ may be the same or different from each other, are hydrogen or a vinyl group independently, S may be an integer of 2 to 1,000.

In one embodiment of the present invention, the mixing ratio of the silicon-based binder and the compound may be 7: 3 to 1: 9 by weight.

Another embodiment is a composition for forming a resin layer, which comprises 9.5 to 70% by weight of a silicone-based binder; 30 to 90% by weight of at least one compound selected from the group consisting of acrylic monomers and epoxy resins; And 0.5 to 20% by weight of initiator.

In another embodiment, the acrylic monomer is selected from the group consisting of bisphenol-ether oxide diacrylate, bisphenol-aeethylene oxide dimethacrylate, bisphenol-aethoxylate diacrylate, bisphenol-aethoxylate diacrylate, bisphenol- (2-hydroxyethyl) isocyanurate, bisphenol-acrylate, bisphenol-acrylate, bisphenol-diacrylate, dicyclopentadienyl diacrylate, pentaerythritol triacrylate, tris (Meth) acrylate, pentaerythritol tetramethacrylate, pentaerythritol trimethacrylate, pentaerythritol trimethacrylate, pentaerythritol triacrylate, bisphenol-adiethacrylate, bisphenol-ester dimethacrylate, dicyclopentadienyl dimethacrylate, -Hydroxyethyl) isocyanurate trimethacrylate, and Other pentaerythritol tetra meth may be at least one member selected from the group consisting of methacrylate.

In another embodiment, the epoxy resin may be at least one selected from the group consisting of a glycidyl type epoxy resin and an alicyclic epoxy resin.

Another embodiment may be a composition for forming a resin layer further comprising the above surfactant.

Another embodiment may be a composition for forming a resin layer further comprising a solvent.

Further, the present invention provides a flexible display substrate in which a glass fiber sheet is impregnated with the resin layer forming composition.

The present invention also provides a method for producing a flexible display substrate comprising a glass fiber sheet and a resin layer formed on both sides of the glass fiber sheet, the method comprising the steps of: impregnating a glass fiber sheet into a composition for forming a resin layer; And irradiating ultraviolet rays onto the glass fiber sheet coated with the composition for forming a resin layer by the impregnation, thereby curing the ultraviolet curable resin.

One embodiment of the present invention is a method for manufacturing a resin layer, comprising: impregnating a glass fiber sheet into a composition for forming a resin layer; Laminating the release film on both sides of the glass fiber sheet coated with the composition for forming a resin layer by the impregnation; Irradiating ultraviolet rays after the step of laminating to cure ultraviolet rays; And separating the release film laminated after the ultraviolet ray irradiation.

Another embodiment may further include a step of applying heat to the UV cured sheet after the ultraviolet curing step at a temperature of 200 to 300 ° C to thermally cure the UV cured sheet.

When a flexible display substrate is manufactured using the composition for forming a resin layer of the present invention, it is possible to replace the glass used in the past, to have excellent moldability, to have a transparent and flexible property, and to exhibit heat resistance, thermal expansion, It has an advantage that a superior flexible display substrate can be manufactured.

Hereinafter, the present invention will be described in detail.

The present invention relates to a composition for forming a resin layer comprising at least one compound selected from the group consisting of a silicone-based binder having the structure represented by the following formula (1), an acrylic monomer and an epoxy resin, and an initiator, a flexible display substrate using the same, And a method of manufacturing a substrate.

[Chemical Formula 1]

In Formula 1, R ₁ to R ₄ may be the same or different from each other, independently represent a C ₁ to C ₁₂ alkyl group, C ₂ to the aryl group of C _12, C ₂ to C ₁₂ aralkyl, or C ₂ to the an alkenyl group of C _12, R ₅ and R ₆ may be the same or different from each other, are hydrogen or a vinyl group independently, S may be an integer of 2 to 1,000.

In the composition for forming a resin layer, the acrylic monomer is preferably an acrylic or methacrylic compound having two or more functionalities. The acrylic monomer may be bisphenol-A ethylene oxide diacrylate, bisphenol- Bisphenol-A ethoxylate diacrylate, bisphenol-A ethoxylate diacrylate, bisphenol-2-ethoxylate diacrylate, bisphenol- Bisphenol-A polyethoxylate diacrylate, bisphenol-A diacrylate, bisphenol-S diacrylate, dicyclopentadienyl diacrylate, Dicyclopentadienyl diacrylate, pentaerythritol triacrylate, triacrylate, tris (2-hydroxyethyl) isocyanurate triacrylate, pentaerythritol tetraacrylate, bisphenol (meth) acrylate, -A dimethacrylate, bisphenol-S dimethacrylate, dicyclopentadienyl dimethacrylate, pentaerythritol trimethacrylate, tris (2- Tris (2-hydroxyethyl) isocyanurate trimethacrylate), and pentaerythritol tetramethacrylate. In the present invention, it is also possible to use one or more selected from the group consisting of tris (2-hydroxyethyl) isocyanurate trimethacrylate and pentaerythritol tetramethacrylate.

The epoxy resin in the composition for forming a resin layer means a resin containing at least one epoxy group in the molecule. For example, the epoxy resin may be a glycidyl type epoxy resin or an alicyclic epoxy resin.

The glycidyl type epoxy resin may be a bisphenol A type epoxy resin, a bisphenol F type epoxy resin, a bisphenol S type epoxy resin, a naphthalene type epoxy resin or a hydrogenated product thereof; An epoxy resin having a dicyclopentadiene skeleton; An epoxy resin having a triglycidyl isocyanurate skeleton; An epoxy resin having a cardo skeleton; Or an epoxy resin having a polysiloxane structure; Lt; / RTI >

The alicyclic resin can be produced by reacting 3,4-epoxycyclohexylmethyl-3 ', 4'-epoxycyclohexanecarboxylate, 1,2,8,9-diepoxy limonene and epsilon -caprolactone oligomers at both ends with 3, 4-epoxycyclohexylmethanol and 3,4-epoxycyclohexanecarboxylic acid, or an epoxy resin having a hydrogenated bisphenol A skeleton.

The mixing ratio of the silicon-based binder and the compound in the composition for forming a resin layer may be 7: 3 to 1: 9 by weight. A silicone-based binder having good flexibility and heat resistance may be used alone, but since the heat-curing temperature is not lower than 150 ° C, a roll-to-roll roll-to-roll process. Therefore, when used in combination with a silicone-based binder and an UV-curing acrylic monomer or epoxy resin, the release film is laminated on both sides of the impregnated glass fiber sheet, , The release film can be removed and the thermosetting can proceed. In this case, the composition ratio of the silicone-based binder and the acrylic monomer or epoxy resin must be appropriately adjusted so that the film is not sticky and can smoothly roll on the roll when the releasing film is removed before the curing is proceeded in the roll- have. Therefore, when the ratio of the silicon-based binder and the compound is higher than 7: 3 by weight, the film is sticky and can not smoothly move on the roll when the releasing film is removed after the photo-curing, If the proportion of the compound is higher than that, the content of the silicon-based binder is too small and the effect of improving the flexibility and heat resistance can not be expected.

The composition for forming a resin layer for forming the resin layer of the present invention may further include an initiator for curing the above-described silicon-based binder and compounds, and the initiator may be a photo polymerization initiator or a thermal polymerization initiator.

The photopolymerization initiator in the present invention means a compound which causes decomposition or bonding by exposure and generates an active species capable of initiating polymerization of the monomer or resin, such as radicals, anions, and cations, and the silicone binder. For example, the photopolymerization initiator may be an acetophenone compound such as 4- (2-hydroxyethoxy) phenyl (2-hydroxy-2-propyl) ketone,? -Hydroxy- ?,? Methoxyacetophenone, 2,2-dimethoxy-2-phenylacetophenone, 2,2-diethoxyacetophenone, 1-hydroxycyclohexylphenylketone, and 2-methyl-1- [4- (methylthio) -Phenyl] -2-morpholinopropane-1 < / RTI > Benzoin ether compounds such as benzoin ethyl ether, benzoin isopropyl ether, and anisoin methyl ether; alpha -ketol compounds such as 2-methyl-2-hydroxypropiophenone; Ketal compounds such as benzyl dimethyl ketal; Aromatic sulfonyl chloride compounds such as 2-naphthalenesulfonyl chloride; Photoactive oxime compounds such as 1-phenone-1,1-propanedione-2- (o-ethoxycarbonyl) oxime; Benzophenone compounds such as benzophenone, benzoylbenzoic acid, 3,3'-dimethyl-4-methoxybenzophenone, and 3,3 ', 4,4'-tetra (t- butylperoxycarbonyl) benzophenone ; Diphenyl (2,4,6-trimethylbenzoylphosphine oxide; and methylbenzoylformate).

The thermal polymerization initiator may be an organic peroxide such as benzoyl peroxide, t-butyl perbenzoate, cumene hydroperoxide, diisopropyl peroxydicarbonate, di-n-propyl peroxydicarbonate, di (2-ethoxyethyl ) Peroxydicarbonate, t-butyl peroxyneodecanoate, t-butyl peroxypivalate, (3,5,5-trimethylhexanoyl) peroxide, dipropionyl peroxide, and diacetyl peroxide; and Azo compounds such as 2,2'-azobisisobutyronitrile, 2,2'-azobis (2-methylbutyronitrile, 1,1'-azobis (cyclohexane-1-carbonitrile) Azo compounds such as 2,2'-azobis (2,4-dimenyl valeronitrile), 2,2'-azobis (2,4-dimethyl-4-methoxy valeronitrile), dimethyl 2,2'-azobis (2-methylpropionate), 4,4'-azobis (4-cyanovaleric acid), 2,2'-azobis (2-hydroxymethylpropionitrile) Bis [2- (2- The 2-yl) may be at least one selected from the group consisting of propane.

Wherein the composition for forming a resin layer contains 9.5 to 70% by weight of a silicon-based binder in the composition for forming a resin layer; 30 to 90% by weight of at least one compound selected from the group consisting of acrylic monomers and epoxy resins; And 0.5 to 20% by weight of initiator. When the content of the silicone-based binder, the compound, and the initiator in the composition for forming a resin layer is outside the above range, the heat resistance, thermal expansion, and flame retardancy may deteriorate.

In the present invention, the composition for forming a resin layer may further contain a surfactant, a solvent and the like in accordance with necessity of manifesting a special function.

The surfactant has a surface modifying effect on the resin layer, and a silicon-based surfactant or a fluorine-based surfactant may be preferable. The silicon-based surfactant may include a silicon group and an ionic group. For example, the ionic group may be an anionic group, and specifically may be carboxylate, sulfonate, phosphonate, sulfate, phosphate.

The surfactant preferably has a solid content of 80 to 100% by weight based on 100% by weight of the surfactant, in order to prevent the surfactant from being generated as a fume upon ultraviolet curing or thermosetting during the process of the flexible display substrate And the flash point is preferably 100 ° C or higher.

The surfactant is preferably contained in an amount of 0.005 to 5 parts by weight, more preferably 0.01 to 1 part by weight, based on 100 parts by weight of the solid content of the composition for forming a resin layer. When the surfactant is contained in an amount of less than 0.005 part by weight, the surface of the resin layer may be insufficiently modified, and if it exceeds 5 parts by weight, heat resistance of the resin layer may be deteriorated.

The solvent may be a ketone, an ether, an ester, an alcohol, a hydrocarbon, acetonitrile, nitromethane, water, or a mixture thereof. For example, the solvent may include ketones such as acetone, methyl ethyl ketone, methyl isobutyl ketone, and cyclohexanone; Ethers such as tetrahydrofuran, 1,4-dioxane and 1,2-dimethoxyethane; esters such as ethyl acetate and ethoxyethyl; Butanol, 2-methyl-1-propanol, 2-methyl-2-propanol, 2-ethoxyethanol, 1-methoxy-2-propanol , 2-butoxyethanol; hydrocarbons such as n-hexane, n-heptane, isooctane, benzene, toluene, xylene, gasoline, light oil and kerosene; Acetonitrile; Nitromethane; Or water, and they may be used alone or in combination of two or more.

The method for fabricating the flexible display substrate includes: impregnating a glass fiber sheet into the composition for forming a resin layer; And irradiating ultraviolet rays onto the glass fiber sheet coated with the composition for forming a resin layer by the impregnation, thereby curing the ultraviolet ray.

The amount of ultraviolet light to be irradiated in the ultraviolet curing step may be varied depending on the kind of components contained in the composition for forming a resin layer and the content of the photopolymerization initiator. In addition, it is preferable that the release film is lined on both sides of the coated glass fiber sheet before the ultraviolet curing step, and the release film laminated on both sides of the coated glass fiber sheet is separated after the ultraviolet irradiation is completed. When laminating a release film, the temperature and pressure of the laminator can be adjusted for the purpose of the invention. By thus laminating the release film to the glass fiber sheet and performing ultraviolet curing, it may be easy to control so that the final thickness of the resin layer to be formed after ultraviolet ray becomes uniform.

Further, according to the kind of the composition to be coated on the glass fiber sheet, it may further include a step of applying heat to the UV-cured sheet after the ultraviolet curing step to thermally cure it. In this case, the heat curing temperature can be 200 to 300 ° C, and the heat curing time can be determined by appropriately adjusting the type of composition and the heat curing temperature. In such a step of thermosetting, when there is a composition having less curing in a stage of ultraviolet curing, it is possible to achieve complete curing through a thermosetting process, thereby improving the heat resistance characteristics of the substrate as a final product.

The substrate may be a glass fiber sheet impregnated with the resin layer forming composition.

The flexible display substrate is manufactured according to the manufacturing method, and the thickness of the substrate may be 10 to 200 탆.

The substrate is characterized by excellent flexibility and heat resistance. For example, the substrate may have a thermal expansion coefficient of 10 ppm / ° C or less.

Hereinafter, the present invention will be described in more detail with reference to Examples, Comparative Examples and Experimental Examples. However, the following examples, comparative examples and experimental examples are for illustrating the present invention, and the present invention is not limited by the following examples, comparative examples and experimental examples, and can be variously modified and changed.

Example  One

20% by weight of bisphenol-A ethylene oxide diacrylate (trade name: Miramer M240 manufactured by MIWON CHEMICAL Co., Ltd.), bisphenol A ethylene oxide dimethacrylate (manufactured by KYOEISHA , 50 wt% of a silicone-based binder having a structure represented by the following formula (R ₁ to R ₃ are methyl groups, R ₄ is a phenyl group, R ₅ and R ₆ are vinyl groups, and S is 10) (Irgacure 184) (manufactured by Basf) and benzoyl peroxide were added in an amount of 2% by weight based on the total amount of the mixed mixture, and the mixture was stirred for 1 hour through a stirrer Followed by stirring to prepare a composition for forming a resin layer.

The glass fiber sheet having a thickness of 40 to 60 μm was used as the composition for forming a resin layer, and the impregnation process was conducted at room temperature for 1 hour or more. Thereafter, a release film of both sides was laminated using a laminator, and a UV curing process was performed using a UV exposing machine. After removing the release films on both sides, a thermosetting process was performed to obtain a final substrate.

Example  2

50% by weight of 3,4-epoxycyclohexylmethyl-3, 10% by weight of bisphenol A ethylene oxide dimethacrylate and the structure of formula 1 (R ₁ to R ₃ are methyl, R ₄ is phenyl, R ₅ and R ₆ are 40% by weight of a silicone-based binder having a vinyl group, S = 10) was first mixed, and then 2% by weight of benzoyl peroxide was added based on the total amount of the mixed mixture and stirred for 1 hour with a stirrer to form a resin layer Lt; / RTI >

The glass fiber sheet having a thickness of 40 to 60 μm was used as the composition for forming a resin layer, and the impregnation process was conducted at room temperature for 1 hour or more. Thereafter, a release film of both sides was laminated using a laminator, and a UV curing process was performed using a UV exposing machine. After removing the release films on both sides, a thermosetting process was performed to obtain a final substrate.

Comparative Example

The composition for forming a resin layer of the present invention was prepared by mixing 25 wt% of bisphenol aethoxylate diacrylate, 15 wt% of ethoxylated bisphenol fluorene diacrylate (HANNONG CHEMICAL, product name: BPF-022) 50% by weight of erythritol tetraacrylate (manufacturer: HANNONG CHEMICAL, product name: PE-044) and 10% by weight of fluorene acrylate having a bivalent functional group (product name: , 2 weight% of 1-hydroxycyclohexyl phenyl ketone was added based on the content of the mixed total mixture, and the mixture was stirred for 1 hour through a stirrer to prepare an impregnation solution. Then, a final substrate was obtained in the same manner as in the above example .

Experimental Example

Evaluation of CTE (Coefficient of Thermal Expansion), TGA (Thermogravimetric Analysis), and surface characteristics after heat treatment was performed on Examples 1 and 2 and Comparative Examples, and the results are shown in Table 1 below.

<CTE measurement method>

The temperature was raised from room temperature to 330 ° C at a rate of 10 ° C / min under a TMA measuring instrument N 2 condition. The temperature was then decreased from room temperature to 330 ° C by 5 ° C / min. The CTE was measured at intervals of 50 ° C from 50 ° C to 300 ° C, and the average value was obtained.

<TGA analysis method>

The temperature was raised from room temperature to 150 ° C at a rate of 10 ° C / min under the condition of a TGA measuring instrument N2, and then held at 150 ° C for 10 minutes. Thereafter, the temperature was raised from 150 ° C. to 300 ° C. at a rate of 10 ° C./min. The temperature was maintained at 300 ° C. for 1 hour and 10 minutes. The weight loss rate (weight loss (%)) were measured.

<Surface Property Evaluation Method>

Roughness was measured by measuring the surface roughness of 1 mm x 1 mm area of the substrate before and after heat treatment at 250 ° C / 10 min using a 10x magnification lens with a 3D Profiler.

division Example 1 Example 2 Comparative Example 1 CTE <7 ppm / ° C <9 ppm / ° C <14 ppm / ° C Weight loss (300 ° C for 1hr) <1% <1.2% <1.5% ? Ra (Roughness) <100 nm <200 nm <600 nm

As shown in Table 1, the CTE was 14 ppm / ° C or less in Comparative Example 1, 7 ppm / ° C or less in Example 1, 9 ppm / ° C or less in Example 2, But less than 1% in Example 1 and 1.2% or less in Example 2. Also, in the case of? Ra, Comparative Example 1 showed 600 nm or less, whereas Example 1 showed 100 nm or less. Example 2 showed 200 nm or less.

Claims (11)

A silicon-based binder having a structure represented by the following formula (1);
At least one compound selected from the group consisting of an acrylic monomer and an epoxy resin; And
An initiator,
The mixing ratio of the silicon-based binder and the compound is 7: 3 to 1: 9 by weight,
Wherein the silicone-based binder is contained in an amount of 9.5 to 70% by weight based on the total composition.
[Chemical Formula 1]

In Formula 1, R ₁ to R ₄ may be the same or different from each other, independently represent a C ₁ to C ₁₂ alkyl group, C ₂ to the aryl group of C _12, C ₂ to C ₁₂ aralkyl, or C ₂ to the _C12 alkenyl group,
R ₅ and R _{6, which} may be the same or different, are independently hydrogen or a vinyl group,
S is an integer of 2 to 1000; delete delete The method according to claim 1,
The acrylic monomer may be at least one selected from the group consisting of bisphenol-ether oxide diacrylate, bisphenol-aeethylene oxide dimethacrylate, bisphenol-aethoxylate diacrylate, bisphenol-aethoxylate diacrylate, bisphenol- (2-hydroxyethyl) isocyanurate triacrylate, tris (2-hydroxyethyl) isocyanurate triacrylate, dicyclopentadienyl triacrylate, dicyclopentadienyl diacrylate, Pentaerythritol tetramethacrylate, tris (2-hydroxyethyl) iso-pentaerythritol tetramethacrylate, pentaerythritol trimethacrylate, pentaerythritol tetramethacrylate, Cyanurate trimethacrylate, and pentaerythritol tetra A is at least one member selected from the group consisting of methacrylate, the resin layer forming composition. The method according to claim 1,
Wherein the epoxy resin is at least one selected from the group consisting of a glycidyl type epoxy resin and an alicyclic epoxy resin. The method according to claim 1,
Wherein the composition further comprises a surfactant. The method according to claim 1,
The composition further comprises a solvent,
Wherein the solvent is a ketone, an ether, an ester, an alcohol, a hydrocarbon, acetonitrile, nitromethane, water, or a mixture thereof. A flexible display substrate, wherein the glass fiber sheet is impregnated with the resin layer forming composition of claim 1. A method of manufacturing a flexible display substrate comprising a glass fiber sheet and a resin layer formed on both sides of the glass fiber sheet,
Impregnating the glass fiber sheet with the resin layer forming composition of claim 1; And
And irradiating ultraviolet rays onto the glass fiber sheet coated with the composition for forming a resin layer by the impregnation, thereby curing the ultraviolet curable resin. 10. The method of claim 9,
Impregnating the glass fiber sheet with the resin layer forming composition of claim 1;
Laminating the release film on both sides of the glass fiber sheet coated with the composition for forming a resin layer by the impregnation;
Irradiating ultraviolet rays after the step of laminating to cure ultraviolet rays; And
And separating the release film laminated after the ultraviolet ray irradiation. 10. The method of claim 9,
Further comprising the step of applying heat to the UV cured sheet at a temperature of 200 to 300 ° C after the ultraviolet curing step to thermally cure the UV cured sheet.