KR101593749B1 - Composite sheet, method for manufacturing the same and displaying apparatus comprising the same - Google Patents

Abstract

The present invention relates to a laminated sheet comprising a first sheet including a reinforcing material impregnated into a matrix and a second sheet formed on at least one side of the first sheet, wherein the second sheet has a surface energy of 55 dyne / cm or more, a modulus of 20 MPa or more, A cross-cut for the first sheet is 90% or more, a method for producing the same, and a composite sheet comprising the composite sheet.

Description

Technical Field [0001] The present invention relates to a composite sheet, a method of manufacturing the same, and a display device including the composite sheet,

The present invention relates to a composite sheet, a manufacturing method thereof, and a display device including the composite sheet.

As substrate materials for display devices, miniaturization, thinness, light weight, impact resistance, flexibility and the like are required. As a material for replacing the glass substrate of the conventional display device, a substrate for a flexible display has been spotlighted.

A matrix impregnated with a woven form of glass fiber or glass fiber can be used as a flexible substrate. However, by including glass fibers, surface roughness may be a problem in the case of stacking a barrier layer on a substrate, and since the barrier layer and the substrate have a modulus difference, the barrier layer can not be stacked on the substrate with high adhesion, Studies are being made on techniques for forming a buffer layer.

In this regard, Korean Patent Laid-Open Publication No. 2013-0022666 discloses a flexible substrate including a silicone rubber-impregnated matrix.

A problem to be solved by the present invention is to provide a composite sheet capable of stably laminating a predetermined component or layer because of high surface energy and high modulus.

Another object to be solved by the present invention is to provide a composite sheet having improved surface roughness and high adhesion of a barrier layer.

Another object of the present invention is to provide a composite sheet having high bonding strength and stability between a matrix and a buffer layer.

Another problem to be solved by the present invention is to provide a composite sheet free from cracks and having high stability.

A further object of the present invention is to provide a method for producing a composite sheet capable of stably stacking a buffer layer with high bonding force.

A composite sheet according to one aspect of the present invention includes a first sheet including a reinforcing material impregnated into a silicon matrix and a second sheet formed on at least one side of the first sheet, wherein the second sheet has a surface energy of 55 dyne / cm Or more, the modulus of 20 MPa or more, and the cross-cut with respect to the first sheet may be 90% or more.

Another aspect of the present invention is a method for producing a composite sheet, comprising: forming a laminate on which a composition for a second sheet and a base film are sequentially formed on a matrix composition impregnated with a reinforcing material; and curing the composition for a second sheet and the composition for a matrix The composition for the matrix and the composition for the second sheet may be in a state of not being fully cured before the curing of the composition for the second sheet and the composition for a matrix.

A display device, which is another aspect of the present invention, includes a substrate, and a member for an apparatus formed on the substrate, and the substrate may include the composite sheet.

The present invention provides a composite sheet capable of stably laminating a predetermined part or layer with high surface energy and high modulus.

The present invention provides a composite sheet with improved surface roughness and high adhesion of a barrier layer.

The present invention provides a composite sheet free from cracks and highly stable.

The present invention provides a composite sheet having high bonding strength and stability between a matrix and a buffer layer.

The present invention provides a method for producing a composite sheet capable of stably stacking buffer layers with high bonding strength.

1 is a cross-sectional view of a composite sheet according to an embodiment of the present invention.
2 is a cross-sectional view of a composite sheet according to another embodiment of the present invention.
3 is a cross-sectional view of a display device according to an embodiment of the present invention.

The present invention is not limited to the above embodiments and various changes and modifications may be made by those skilled in the art without departing from the scope of the present invention. The present invention may be embodied in many different forms and is not limited to the embodiments described herein. In order to clearly illustrate the present invention, parts not related to the description are omitted, and the same or similar components are denoted by the same reference numerals throughout the specification. In the present specification, "upper" and "lower" are defined with reference to the drawings, and "upper" may be changed to "lower" and "lower" may be changed to "upper" depending on viewing time.

In the present specification, "modulus" is measured by applying a force of 10 mN with a micro indentor (Vicker indenter) for 10 seconds using a micro indentation device (HM2000, Fisher), creeping for 3 seconds and relaxation for 10 seconds .

In the present specification, "crosscut" means that after cutting only the second sheet of the composite sheet to a predetermined number of samples N having the same size as 1 mm x 1 mm (width x length), the second sheet is cut from the composite sheet to 3M (810, (N / N) relative to the number of samples remaining in the composite sheet after peeling with respect to the number of samples N of the second sheet before peeling (ASTM D-3359) when peeled off at 180 deg. Lt; / RTI >

"Cure rate" as used herein is 1725cm ^{- 1} a prior to curing the composition by Reference to the intensity of the absorption peak at the peak in the vicinity of 1410cm ^-1 A, after curing of the absorption peak of 1410cm ^-1 in the vicinity of the peak When the intensity is B, | 1- (B / A) | x < / RTI >

Hereinafter, a composite sheet according to an embodiment of the present invention will be described with reference to FIG. 1 is a cross-sectional view of a composite sheet according to an embodiment of the present invention. 1, a composite sheet 100 according to an embodiment of the present invention includes a first sheet 10 including a stiffener 5 impregnated into a matrix 1, And a second sheet 20 formed on the surface.

The surface energy of the second sheet 20 may be 55 dyne / cm or more, and the modulus may be 20 MPa or more. When the surface energy and modulus of the second sheet are in the above ranges, even if a predetermined part or layer is laminated on the upper surface of the second sheet, the composite sheet is not easily separated from the composite sheet, and no breakage is caused in the composite sheet. For example, the surface energy of the second sheet 20 can be from 55 to 70 dyne / cm and the modulus from 20 MPa to 5 GPa.

In one embodiment of the present invention, by forming a second sheet 20 having a higher surface energy than the first sheet 10 and having a modulus equal to or greater than that of the first sheet 10 on the upper surface of the first sheet 10 The surface energy and modulus of the composite sheet can be increased to stably deposit the barrier layer on the composite sheet and the surface of the first sheet 10 is modified by the second sheet 20, ) Can also be lowered. That is, in the embodiment of the present invention, the modulus of the first sheet 10 is M1, the modulus of the second sheet 20 is M2, the surface energy of the first sheet 10 is S1, When the surface energy is S2, M1? M2 and S1 <S2. As described above, the second sheet can improve the surface roughness of the composite sheet as a buffer layer and improve the adhesion of the barrier layer.

The thickness of each of the first sheet 10 and the second sheet 20 is not particularly limited. Assuming that the thickness of the first sheet 10 is T1 and the thickness of the second sheet 20 is T2, T1> T2 . Within the above range, the composite sheet can be used as a flexible substrate. Specifically, T1 may be 15 to 200 mu m, and T2 may be 1 to 15 mu m.

The first sheet 10 and the second sheet 20 may be separately manufactured and then laminated by an adhesive layer or the like. However, by manufacturing the first sheet 10 and the second sheet 20 integrally, The effect of improving the modulus can be increased, and the bonding force and stability between the first sheet and the second sheet can be enhanced. The "integral type" means a state in which no adhesive layer or the like is interposed between the first sheet and the second sheet, and the first sheet and the second sheet are not separated by a physical force. In one embodiment, the second sheet 20 may have a crosscut of 90% or more, for example 90 to 100%, for the first sheet 10. In the above range, the second sheet has a high bonding force with respect to the first sheet, so that the stability of the composite sheet can be enhanced.

The surface roughness Ra of the composite sheet 100 may be 100 nm or less, specifically 50 nm or less, more specifically 1 to 50 nm. Within this range, it can be used for substrate applications. The composite sheet may have a thermal expansion coefficient of 0 ppm / ° C to 400 ppm / ° C, specifically 0 ppm / ° C to 10 ppm / ° C, more specifically, 3 ppm / ° C to 7 ppm / Within this range, thermal deformation can be suppressed during production of the flexible substrate. The thermal expansion coefficient is measured by a thermo-mechanical analyzer (expansion mode, force 0.05N) according to ASTM E 831 method and measured from the curve of the sample length according to the temperature (30 to 250 ° C) can do. The composite sheet may have a thickness of 15 탆 to 200 탆. Within this range, it can be used as a composite sheet for a flexible substrate. The composite sheet may be transparent in the visible light region.

The matrix 1 may have a tensile elongation of 15% or more, for example 15 to 40%, and the modulus of the matrix may be 5 to 20 MPa, for example 5 to 15 MPa. In the above range, the composite sheet has good thermal stability and heat resistance and cracks may not occur even at high temperature treatment, flexibility is good, cracks do not occur at the interface between the matrix and the reinforcing material, The separation from the composite sheet can be prevented. The term "tensile elongation" means a value measured at a speed of 50 mm / min with TA.XT.plus (TA instrument) for a matrix specimen (Width 5 mm, Length 20 mm).

The matrix 1 may be a silicone-based matrix, and may include a cured silicone rubber, specifically a linear silicone rubber. The linear silicone rubber has a structure in which siloxane units are connected in a predetermined length to increase the tensile elongation of the matrix, so that the thermal expansion of the matrix and the thermal expansion difference between the reinforcing material can be alleviated even at high temperature treatment of the composite sheet, and flexibility as a substrate can be obtained.

Specifically, the linear silicone-based rubber may be a siloxane oligomer or polymer having a curable functional group, and may be, for example, a copolymer comprising a first repeating unit having a curable functional group and at least one second repeating unit having no curable functional group Lt; / RTI &gt; The siloxane having a curable functional group may be formed by a polymerization reaction of a first monomer containing a curable functional group and at least one second monomer containing a curable functional group, wherein the first monomer containing a curable functional group is a By weight or less, for example, 0.01 to 1.0% by weight. Within the above range, the curable functional group, which is a crosslinking site, is added in a specific range, so that the occurrence of cracks is low and the stability of the composite sheet can be enhanced. The above-mentioned "curable functional group" means a group capable of curing the matrix composition and performing a crosslinking reaction with a non-rubbery silicone compound or a crosslinking agent, and includes an unsaturated hydrocarbon group having an unsaturated bond at the terminal and having 2 to 12 carbon atoms, , Or an allyl group.

For example, the linear silicone-based rubber may be a vinyl group-containing polydimethylsiloxane (PDMS). Vinyl group-containing polydimethylsiloxane can be prepared from a composition for the preparation of silicone-based rubbers including phenylmethyldimethoxysilane (PMDMS), dimethyldimethoxysilane (DMDMS), and vinylmethyldimethoxysilane (VMDMS) Specifically, it can be prepared by hydrolysis, polymerization and end-capping reaction of PMDMS, DMDMS, VMDMS. At this time, the VMDMS may be contained in an amount of 1.0 wt% or less, for example, 0.01 to 1.0 wt%, based on the sum of PMDMS, DMDMS and VMDMS. In the above range, the vinyl group which is a crosslinking site is included in a specific range, thereby maximizing the tensile elongation of the matrix and enhancing the stability of the composite sheet. In this case, the PMDMS may be included in an amount of 10 to 80% by weight and the DMDMS may be included in an amount of 10 to 90% by weight, specifically 19 to 85% by weight, depending on the target refractive index in the sum of PMDMS, DMDMS and VMDMS. Within the above range, the refractive index of the target composite sheet can be ensured.

In one embodiment, the linear silicone-based rubber may be a linear siloxane oligomer or polymer having a curable functional group and an aliphatic hydrocarbon group, and / or an aromatic hydrocarbon group, and the like. The aliphatic hydrocarbon group, the aromatic hydrocarbon group and the like are for supporting the matrix and for bonding between the reinforcing materials. In particular, the aromatic hydrocarbon group can increase the permeability of the composite sheet by matching the refractive index between the reinforcing material and the matrix. Specifically, the linear silicone-based rubber may comprise the following Formula 1, Formula 2, and Formula 3:

&Lt; Formula 1 >

(2)

(3)

Wherein R _a , R _b , R _c , R _d , R _e , R _f , R _g and R _h are each independently selected from the group consisting of hydrogen, alkyl group, having 6 to 20 carbon atoms of the aryl group, C7 to C20 arylalkyl group, or terminal carbon atoms, an unsaturated hydrocarbon group of 2 to 12 having a double bond in the a, R _a, R _b, R _c, R _d, R _e, At least one of R _f , R _g and R _h is an unsaturated hydrocarbon group having 2 to 12 carbon atoms and having a double bond at the terminal). More specifically, the linear silicone rubber may include the repeating units of the formula (1) and the repeating units (2) and (3) at the terminal.

Specifically, the linear silicone-based rubber may comprise repeating units of the following formula:

&Lt; Formula 4 >

(In the formula (4), * is a connecting site of the element, 0 <x <1, 0 <y <1, 0? Z? 1, and Me is a methyl group).

For example, a linear silicone-based rubber may be represented by the following formula 5 or 6:

&Lt; Formula 5 >

(In the formula 5, 10? X? 400, 10? Y? 700, 0? Z? 700, and Me is a methyl group).

(6)

(In the formula 6, 10? X? 400, 10? Y? 700, 0 <z? 700, and Me is a methyl group).

Specifically, in the above formulas (5) and (6), x, y and z may be integers.

The linear silicone rubber may have a number average molecular weight (Mn) of 2000 to 50,000 g / mol. Within this range, the matrix can be supported.

In one embodiment, the matrix can be formed by curing a composition for a matrix comprising a linear silicone-based rubber and a cross-linker. The crosslinking agent is a monomolecular or oligomer having two or more -Si-H groups so as to hydrosilylate with a curable functional group of a linear silicone rubber, and can be activated by heat or UV to perform a hydrosilyl reaction. In addition, the cross-linking agent having a siloxane unit can realize a high heat resistance effect as well as compatibility with a resin such as a linear silicone rubber. The linear silicone rubber in the composition may be contained in an amount of 80 to 99% by weight, and the crosslinking agent may be contained in an amount of 1 to 20% by weight based on the solid content. In the above range, the occurrence of cracks is low and the stability of the composite sheet can be enhanced.

For example, the crosslinking agent may comprise the following structural formulas (7), (8), and (9)

&Lt; Formula 7 >

(8)

&Lt; Formula 9 >

(In the formula 7 to 9, and * in a joint of the elements, R _i, R _j, R _k, R _l, R _m, R _n, R _o, R _p is independently hydrogen, C 1 -C 10 An alkyl group, an aryl group having 6 to 20 carbon atoms, or a silyloxy group, and at least two of R ₁ , R _j , R _k , R ₁ , R _m , R _n , R _o and R _p are hydrogen. The "silyloxy group" means an -Si-O- group having an alkyl group having 1 to 10 carbon atoms or a hydrogen atom. That is, the crosslinking agent may include the repeating unit represented by the formula (7), while the terminals may include the following formulas (8) and (9).

Specifically, the crosslinking agent may be a single compound selected from the group consisting of compounds represented by any one of the following formulas (10) to (14), and oligomers of the following formula (15)

&Lt; Formula 10 >

&Lt; Formula 11 >

&Lt; Formula 12 >

&Lt; Formula 13 >

&Lt; Formula 14 >

&Lt; Formula 15 >

(In the formula (15), 0 ? X? 30, 0 ? Y? 40, 0 ? Z ? 40, and Me is a methyl group. The number average molecular weight (Mn) of the crosslinking agent of Formula 15 may be 200 to 3000 g / mol. Within this range, excellent compatibility with a resin such as a linear silicone rubber or the like can be obtained and the curing efficiency can be increased.

The ratio of the number of moles of the silicon-curing functional group (e.g., Si-vinyl group) in the linear silicone rubber to the weight average molecular weight of the linear silicone rubber is defined as A, A: B may be from 1: 1 to 1: 3, for example, from 1: 1 to 1: 2, where B is the ratio of the number of moles of Si- In the above range, the occurrence of cracks is low and the stability of the composite sheet can be enhanced.

The composition for a matrix may further comprise at least one of a catalyst and an inhibitor.

The catalyst is used for increasing the crosslinking reaction rate, and a catalyst commonly used in the production of a composite sheet for a flexible substrate can be used. For example, the catalyst may be a platinum-based or rhodium-based catalyst, a complex of platinum and an organic compound, a platinum-vinylated organosiloxane complex, a rhodium-olefin complex, or the like. Specifically, the catalyst may be a vinylalkylsilane platinum complex, a platinum black, a chloroplatinic acid, a chloroplatinic acid-olefin complex, a chloroplatinic acid-olefin complex, A chloroplatinic acid-alcohol complex, or a mixture thereof may be used. The catalyst may comprise from 2 ppm to 2000 ppm, for example from 5 ppm to 500 ppm, based on the weight of the metal, for the linear silicone rubber. Within the above range, the crosslinking reaction rate can be sufficiently increased, and unnecessary use of the catalyst can be avoided.

The inhibitor inhibits the action of the catalyst at room temperature and does not inhibit the catalyst in the course of curing at high temperature, so that the composition can be cured at a high temperature and an inhibitor commonly used in the manufacture of a composite sheet for a flexible substrate can be used. For example, the inhibitor may be selected from the group consisting of acetylenic alcohols, pyridine, and the like, including 3,5-dimethyl-1-hexyn- Phosphine, organic phosphite, unsaturated amide, dialkyl carboxylate, dialkyl acetylene dicarboxylate, alkylated malateate (also referred to as &quot; alkylated maleate, diallyl maleate, or mixtures thereof. The inhibitor may be included at from 100 ppm to 2500 ppm for the linear silicone rubber. Within this range, it is possible to control the suppression of the catalyst depending on the temperature, and the high temperature curing.

The stiffener is embeddable within the matrix 1, and may be specifically included in the matrix in a dispersed, single layer or multilayer structure. 1 shows only the structure in which the reinforcing material 5 is impregnated in the matrix 1 in layers, but the present invention is not limited thereto. The reinforcing materials may be dispersed in a matrix, impregnated in a woven form, or arranged in a uni direction And may be impregnated. Further, the reinforcing material may be formed as a single layer or a plurality of layers. The reinforcing material in the composite sheet may be contained in an amount of 30 to 70% by weight, for example, 40 to 60% by weight. Within the above-mentioned range, the high heat resistance and mechanical properties of the flexible substrate can be secured, transparency, flexibility and light weight can be improved, and flexibility of the composite sheet can be provided.

The stiffener may have a refractive index difference with respect to the matrix (refractive index of the stiffener - absolute value of the refractive index of the matrix) of 0.01 or less. Within this range, it can have excellent transparency and translucency. For example, the refractive index difference may be from 0 to 0.005, for example from 0.0001 to 0.005. Specifically, the reinforcing material may have a refractive index of 1.5 or less, specifically 1.47 to 1.48. The reinforcing material having a refractive index of 1.5 or less has a small difference in refractive index from the silicone matrix, so that the composite sheet can secure transparency. The reinforcing material may have a coefficient of thermal expansion of 10 ppm / ° C or less, specifically 3 to 5 ppm / ° C. When such a reinforcing material is used, the thermal expansion coefficient of the entire composite sheet can be lowered, have. The thermal expansion coefficient is measured by a thermo-mechanical analyzer (expansion mode, force 0.05N) according to ASTM E 831 method and measured from the curve of the sample length according to the temperature (30 to 250 ° C) can do. Specifically, the reinforcing material may include at least one selected from the group consisting of glass fiber, glass fiber cloth, glass fabric, glass nonwoven fabric, glass mesh, Do not.

Hereinafter, a matrix of another embodiment of the present invention will be described. The matrix of another embodiment of the present invention may comprise a cured product of said linear silicone-based rubber, said crosslinking agent, and a composition for a matrix comprising a non-rubbery silicone compound. By further including the non-rubbery silicone compound, modulus control of the composite sheet can be facilitated by controlling the molar ratio between the linear silicone rubber and the non-rubbery silicone compound. Is substantially the same as the matrix of the embodiment of the present invention except that it includes a non-rubbery silicone compound.

The non-rubbery silicone compound may be, for example, a cyclic siloxane compound. The cyclic siloxane compound has a structure in which siloxane units are linked in the form of a ring to increase the modulus of the composite sheet. The cyclic siloxane compound may include a curing functional group and an aliphatic hydrocarbon group and / or an aromatic hydrocarbon group, and the curable functional group may be an unsaturated hydrocarbon group having 2 to 12 carbon atoms having a double bond at the terminal, for example, a vinyl group, .

In embodiments, the cyclic siloxane compound is a cyclic siloxane having 3 to 10 linked homo- or hetero- siloxane units, such as cyclotrisiloxane, cyclotetrasiloxane, cyclopentasiloxane, cyclopentasiloxane, A compound in which at least one of silicones such as cyclohexasiloxane, cycloheptasiloxane, or cyclooctasiloxane is bonded to the above-described curable functional group, and the like. For example, cyclic siloxane compounds can include tetravinyltetramethylcyclotetrasiloxane, derivatives prepared from tetravinyltetramethylcyclotetrasiloxane, derivatives prepared from tetramethylcyclotetrasiloxane, and the like .

In one embodiment, the cyclic siloxane compound can be represented by the formula:

&Lt; Formula 16 >

(Wherein R ₁ , R ₂ , R ₃ , R ₄ , R ₅ , R _{6 ,} R _{7 and} R ₈ each independently represent an alkyl group having 1 to 10 carbon atoms, an aryl group having 6 to 20 carbon atoms, , An allyl group, an allyloxy group, a vinyloxy group, or a group represented by the following formula (17)

&Lt; Formula 17 >

(In the above formula (17), * is a connecting site to Si in the above formula (16)

R ₉ is an alkylene group having 1 to 10 carbon atoms or an arylene group having 6 to 20 carbon atoms and R ₁₀ , R ₁₁ and R ₁₂ each independently represent an alkyl group having 1 to 10 carbon atoms, an aryl group having 6 to 20 carbon atoms, , An allyl group, an allyloxy group, and a vinyloxy group; X ₁ and X ₂ each independently represent a single bond, O, S, or NR (R is hydrogen or an alkyl group having 1 to 10 carbon atoms)

_{R 1, R 2, R 3} , R 4, R 5, R 6, R 7, R one or more of the ₈ is a vinyl group, an allyl group, an allyloxy group, a vinyloxy group, R _10, R _11, R ₁₂ of the one or more vinyl group formula 17, R _10, R _11, R ₁₂ is one or more of allyl group of the formula 18, R _10, R _11, R one or more of ₁₂ the allyloxy group formula 17, or R _10, R _11, R &lt; ₁₂ &gt; is a vinyloxy group.

The derivative can be prepared by a conventional method. For example, it can be prepared by converting an alkyl group in a tetravinyl tetraalkylcyclotetrasiloxane to a halogenated alkyl group and reacting a curable functional group-containing compound such as allyl alcohol, vinyl alcohol or the like under a Karstedt platinum catalyst.

Specifically, the cyclic siloxane compound may be represented by any one of the following formulas (18) to (43), but is not limited thereto:

&Lt; Formula 18 >

(19)

(20)

(21)

(22)

&Lt; Formula 23 >

&Lt; EMI ID =

&Lt; Formula 25 >

(26)

&Lt; Formula 27 >

(28)

(29)

(30)

(31)

(32)

&Lt; Formula 33 >

(34)

&Lt; Formula 35 >

&Lt; EMI ID =

(37)

&Lt; Formula 38 >

&Lt; EMI ID =

&Lt; EMI ID =

&Lt; EMI ID =

(42)

&Lt; Formula 43 >

(In the above Chemical Formulas 18 to 43, Me is a methyl group and Ph is a phenyl group).

The ratio of the number of moles of the silicon-curing functional group (e.g., Si-vinyl group) in the non-rubbery silicone compound to the molecular weight of the non-rubbery silicone compound in the matrix composition is represented by C, A is 1: 1 to 6: 1, for example, 3: 1 to 6: 1, where A is the ratio of the number of moles of the silicon-curing functional group (e.g., Si- . Within the above range, the composite sheet may have excellent thermal stability. When the ratio of the number of moles of silicon-H (Si-H) in the cross-linking agent to the (weight) average molecular weight of the cross-linking agent is B, the ratio of (A + C): B is 1: 1 to 1: 3, 1: 1 to 1: 2. In the above range, the occurrence of cracks is low and the stability of the composite sheet can be enhanced.

In the composition for a matrix, the linear silicone rubber, the non-rubber silicone compound and the crosslinking agent may be contained in an amount of 60 to 80% by weight, 1 to 30% by weight, and 1 to 20% by weight, respectively. Within this range, it is possible to prevent the permeability of the composite sheet from being hindered by the unreacted material due to the reaction of the appropriate range of crosslinking sites.

The second sheet 20 is a conventional resin having a curing functional group and has the above-described surface energy after curing and does not limit the type of resin if the above-described modulus range can be realized on the first sheet 10 . For example, the second sheet may be made of acrylic resin or the like.

Hereinafter, a composite sheet according to another embodiment of the present invention will be described with reference to FIG. 2 is a cross-sectional view of a composite sheet according to another embodiment of the present invention. Referring to FIG. 2, a composite sheet 200 according to another embodiment of the present invention includes a first sheet 10 including a reinforcing material 5 impregnated into a matrix 1, A second sheet 20 formed on the second sheet 20, and a barrier layer 30 formed on the upper surface of the second sheet 20. Is the same as the composite sheet of the embodiment of the present invention except that the barrier layer 30 is further included. In addition, although only one barrier layer is formed on the upper surface of the matrix in FIG. 2, the barrier layer may be formed in two or more layers, or may be formed on the bottom surface as well as the top surface of the matrix.

The barrier layer 30 may be formed on one surface of the second sheet 20 to realize the effect of maximizing the gas barrier property, moisture permeability, mechanical properties, or smoothness of the composite sheet 200. In one embodiment, the barrier layer 30 may include one or more of silicon nitride, silicon oxide, silicon carbide, aluminum nitride, indium tin oxide (ITO), and indium zinc oxide (IZO). The modulus of the barrier layer 30 may be 5 to 20 GPa, specifically 10 to 20 GPa, and the thickness may be 5 to 300 nm. Within this range, low surface roughness and effective moisture control effect can be obtained without affecting the permeability of the composite sheet.

The barrier layer 30 may be formed on the surface of the second sheet 20 by physical vapor deposition, chemical vapor deposition, coating, sputtering, evaporation, ion plating, wet coating, or organic inorganic multilayer coating.

Hereinafter, a method for manufacturing a composite sheet according to an embodiment of the present invention will be described. A method for producing a composite sheet according to an embodiment of the present invention includes: forming a laminate having a composition for a second sheet and a base film sequentially formed on a matrix composition impregnated with a reinforcing material; and forming a composition for a second sheet and a composition for a matrix And the composition for a matrix and the composition for a second sheet may not be fully cured before curing the composition for a second sheet and the composition for a matrix. The "completely cured" may mean that the composition for a matrix and the composition for a second sheet are each cured at a curing rate of 90% or more.

The composition for the second sheet is a composition comprising a resin for forming the second sheet described above, and the resin may be coated in a state where it is dissolved in a common solvent such as methyl ethyl ketone (MEK).

The laminate may be formed by coating the matrix composition on the base film coated with the composition for the second sheet and impregnating the reinforcing material or by laminating the base film coated with the composition for the second sheet onto the matrix impregnated with the reinforcement . The matrix impregnated with the reinforcing material may be prepared by coating a matrix composition on a base film and impregnating a reinforcing material, wherein the composition for the second sheet and the composition for a matrix may not be completely cured. The composition for a second sheet and the composition for a matrix are cured at the same time in a state in which they are not completely cured so that the second sheet can be stably formed in a high bond on the matrix.

The base film is not particularly limited as long as it can stably maintain the composition for the second sheet and can be easily peeled off from the second sheet. For example, the base film may be a polyester film such as polyethylene terephthalate (PET). In addition, the base film may further include a primer layer for ease of coating the second sheet composition. The primer layer may be formed of acrylic, polyester, or the like. The base film may have a thickness of 10 to 100 mu m. Within this range, the composition for the second sheet can be stably maintained.

The substrate film coated with the composition for the second sheet is formed by coating the composition for the second sheet on the base film, wherein the coating thickness of the composition for the second sheet is 1 to 10 Mu m. The coating method is not particularly limited, and may be spin coating, die coating, or the like.

The composition for the second sheet may be partially cured before curing, specifically before contacting the composition for a matrix. This makes it possible to stably fix the composition for the second sheet to the base film, and a part of the curable functional groups remaining in the resin for the second sheet is cured with the curable functional groups contained in the matrix, The bonding force can be increased and the second sheet can be easily peeled off from the substrate film at a later stage. Specifically, the composition for the second sheet can be cured at a curing rate of 10 to 50%. Within the above range, the composition for the second sheet can be stably fixed to the base film, and the bonding force between the first sheet and the second sheet can be increased. For this purpose, the curing is preferably carried out at a low light dose, for example at a UVA wavelength of 300 mJ or less, for example 10 to 300 mJ, for 1 to 60 seconds.

After the laminate is formed, the composition for a matrix and the composition for a second sheet can be cured. The curing method is not particularly limited, and for example, thermal curing, light curing, or a combination thereof can be used. The thermal curing may be performed at 30 to 100 캜 for 1 to 3 hours, but is not limited thereto. Photocuring can be performed at 300 to 1000 mJ for 10 seconds to 5 minutes.

The method for manufacturing a composite sheet according to an embodiment of the present invention may further include a step of peeling the base film, wherein the base film is peeled off by a chemical method within a range that does not affect physical properties or physical properties of the composite sheet But is not limited thereto.

In the above description, only the case where the laminate for the second sheet and the base film are sequentially formed on one side of the composition for the matrix impregnated with the reinforcing material is described. However, when the composition for the second sheet and the base film are sequentially formed on both sides of the matrix- The same can be applied to the case where the formed laminate is formed.

The display device of the present invention may include the composite sheet. The display device may be, for example, a flexible liquid crystal display device, a flexible organic light emitting diode display device or the like, but is not limited thereto. The display device includes a substrate and a member for an apparatus formed on the substrate, and the member for the apparatus may include an organic light emitting element, a liquid crystal, or the like.

The display device of the present invention may include the composite sheet. The display device may be, for example, a flexible liquid crystal display device, a flexible organic light emitting diode display device or the like, but is not limited thereto. The display device includes a substrate and a member for an apparatus formed on the substrate, and the member for the apparatus may include an organic light emitting element, a liquid crystal, or the like.

Hereinafter, a display device according to an embodiment of the present invention will be described with reference to FIG. 3 is a cross-sectional view of a display device according to an embodiment of the present invention. 3, a display device according to an embodiment of the present invention includes a substrate 110, a buffer layer 25 formed on the substrate 110, a gate electrode 41 formed on the buffer layer 25, And a gate insulating film 40 formed between the electrode 41 and the buffer layer 25. In the gate insulating film 40, an active layer 35 including source and drain regions 31, 32, and 33 is formed. An interlayer insulating film 51 having source and drain electrodes 52 and 53 is formed on the gate insulating film 40. A passivation layer 61 including a contact hole 62 is formed on the interlayer insulating film 51, A first electrode 70, and a pixel defining layer 80 are formed. The organic emission layer 71 and the second electrode 72 are formed on the pixel defining layer 80 and the substrate 110 may include the composite sheet.

Hereinafter, the present invention will be described in more detail by way of examples, but these examples are for illustrative purposes only and should not be construed as limiting the present invention.

Manufacturing example : Linear silicon system Rubber  Produce

And synthesized by using phenylmethyldimethoxysilane (PMDMS), dimethyldimethoxysilane (DMDMS), and vinylmethyldimethoxysilane (VMDMS). After PMDMS, DMDMS and VMDMS were weighed (PMDMS: DMDMS = 3: 2 (weight ratio), adding equivalent of VMDMS: 1.0 wt% in PMDMS + DMDMS + VMDMS) and 1 hour at 70 ° C under DIW (deionized water) / KOH Followed by hydrolysis. The polymerization reaction was carried out at 90 ° C, Toluene and H ₂ O were added, the temperature was lowered to 25 ° C, and the reaction solution was washed with H ₂ O. After that, 1,3-divinyltetramethyldisiloxane (Vi-MM) was added and the end capping was performed at 50 ° C for 5 hours. The reaction mixture was washed with H ₂ O at room temperature, And the final linear silicone rubber was synthesized. The number average molecular weight (Mn) of the synthesized linear silicone rubber was 7,000 g / mol.

Example  One

A linear silicone rubber of Production Example 1, a tris-silane (tris (dimethylsiloxy) phenylsilane, purity: 98% or more, JJ Chem), a crosslinking agent, a non-rubbery silicone compound tetravinyl tetra (Surfynol) and Karstedt catalyst (Umicore) were blended in a weight ratio of 6: 2: 1, and each of the inhibitors (Surfynol) and Karstedt catalyst (Umicore) was added to a linear silicone rubber 1000 ppm and 500 ppm, and stirred to prepare a composition for a matrix. A mixture of SSH-1001LV (Shin-A T & C) and MHIC-11 (MNP Co.) in an amount of 1: 1 by weight was diluted with methyl ethyl ketone (MEK) to a solid content of 50% by weight and polyethylene terephthalate Lt; / RTI &gt; thick, 38 mu m thick, primer coated product). After the solvent MEK was removed, a part of the acrylic resin was cured by irradiation with UV 300 mJ (curing rate: 30%). The thickness of the cured acrylic resin was 2 to 3 占 퐉. The PET composition was impregnated with a glass fiber cloth (refractive index: 1.48, coefficient of thermal expansion: 3 ppm / 占 폚), and a PET film having no acrylic resin on one side and a partially cured PET film on the other side And a second sheet which is an acrylic resin layer formed on the silicone resin layer, the first sheet being a silicone resin layer impregnated with a glass fiber cloth and being peeled off both PET films, To prepare a composite sheet.

Example  2

A composite sheet was prepared in the same manner as in Example 1, except that a PET film partially cured of acrylic resin was applied to both sides of a composition for a matrix impregnated with glass fiber cloth.

Comparative Example  One

The first sheet was prepared by curing the composition for a matrix impregnated with the glass fiber cloth and the uncured acrylic resin on the first sheet thus prepared was re-impregnated with an uncoated PET film and cured, 1, a composite sheet was prepared.

Comparative Example  2

A first sheet is prepared by curing a composition for a matrix impregnated with a glass fiber cloth, corona treatment is performed on the first sheet thus prepared, and then an uncured PET film is coated on the first sheet, , And then cured, to prepare a composite sheet.

Comparative Example  3

A first sheet is prepared by curing a composition for a matrix impregnated with a glass fiber cloth, a UV ozone treatment is applied to the first sheet, and then an uncured acrylic resin is coated on the first sheet A composite sheet was prepared in the same manner as in Example 1, except that the PET film was re-impregnated and cured.

Comparative Example  4

The composition for a matrix impregnated with glass fiber cloth was cured to prepare a first sheet and a composite sheet was produced without additional impregnation of an acrylic resin.

The following properties of the composite sheets of Examples 1 to 2 and Comparative Examples 1 to 4 were measured and are shown in Table 1 below.

(1) Surface energy: The contact angle was measured using a Phoenix 300 Contact Angle Analyzer manufactured by SEO Corporation. The surface energy was calculated by applying the "Owens-Wendt-geometric" method to the contact angle. Specifically, a drop (5 to 8 ㎕) was dropped to the acrylic resin layer, which is the second sheet, of the composite sheet to be measured for the deionized water and the diiodomethane, and the contact angle of the two solvents was adjusted to room temperature (25 캜) And the surface energy was calculated using the Owens-Wendt-geometric equation, which is often used as a surface energy calculation equation. Surface energy was also calculated for the silicone resin layer in the same manner.

(2) Modulus: The acrylic resin layer as the second sheet of the composite sheet was subjected to a force of 10 mN for 10 seconds with a micro indentor (Vicker indenter) using a micro indentation equipment (HM2000, Fisher) creep), and relaxation for 10 seconds. In the same manner, the modulus was calculated for the glass portion of the silicone resin layer and the window portion of the silicone resin without warp and warp.

(3) Surface roughness (Ra): The surface of the acrylic resin layer in the composite sheet was measured using an optical profiler (ZYGO, 700s).

(4) Creation of cracks: The occurrence of cracks at 25 占 폚 of the composite sheet was measured by an optical microscope in a reflection mode. X for cracks on the surface of the composite sheet, and 0 for cracks.

(5) Cross-cut: Measure the degree of bonding between the silicone resin layer and the acrylic resin layer. A cross hatch cutter (YCC-230/1) was used to cut only the acrylic resin layer of the composite sheet in the width x length (1 mm x 1 mm) (ASTM D-3359) using a 3M standard tape (810, 18 mm) at an angle of 180 °. The acrylic resin layer was peeled off from the silicone resin layer. The number of samples (100 pieces) of the acrylic resin layer before peeling was calculated as a ratio to the number of acrylic resin layers remaining on the composite sheet after peeling.

Acrylic resin layer
Thickness (㎛) Surface energy
(dyne / cm) Modulus
(MPa) Surface roughness
(nm) Crack occurrence Crosscut
(%) Acrylic resin layer The silicone resin layer acryl
Resin layer The silicone resin layer Example 1 3 55 32 400 15 80 × 100 Example 2 6 55 32 400 15 80 × 100 Comparative Example 1 3 55 32 400 15 70 ○ 0 Comparative Example 2 3 55 45 400 15 80 ○ 30 Comparative Example 3 3 55 48 400 15 100 ○ 40 Comparative Example 4 0 - 32 - - 150 - -

As shown in Table 1, the composite sheet of the present invention has a high surface energy, a high modulus, and a low surface roughness, so that a predetermined layer can be stably stacked on the composite sheet, and the cross- It was confirmed that the bonding strength and stability were high and the stability was high because no crack occurred.

On the other hand, the composite sheets of Comparative Examples 1 to 3 were cracked to have low stability and low crosscut, so that the bonding force and stability between the matrix and the buffer layer were low. The composite sheet of Comparative Example 4, which did not contain an acrylic resin layer, had a high surface roughness.

Claims (15)

A first sheet comprising a reinforcing material impregnated in a silicone matrix, and
And a second sheet formed on at least one side of the first sheet,
The second sheet has a surface energy of 55 dyne / cm or more, a modulus of 20 MPa or more,
Wherein the crosscut of the second sheet relative to the first sheet is 90% or more. The composite sheet according to claim 1, wherein the second sheet has a surface roughness (Ra) of 100 nm or less. The composite sheet according to claim 1, wherein M 1 and M 2 denote the modulus of the first sheet and the modulus of the second sheet, respectively. The composite sheet according to claim 1, wherein the first sheet and the second sheet are integral with each other. The composite sheet according to claim 1, wherein the matrix comprises a cured product of a composition for a silicone-based rubber-containing matrix. 6. The composite sheet according to claim 5, wherein the silicone rubber comprises a repeating unit represented by the following formula (4)
&Lt; Formula 4 >

(In the formula (4), * is a connecting site of the element, 0 <x <1, 0 <y <1, 0? Z? 1, and Me is a methyl group). The composite sheet according to claim 5, wherein the composition for a matrix further comprises a cyclic siloxane compound. The composite sheet according to claim 1, wherein the reinforcing material is a composite sheet comprising at least one selected from the group consisting of glass fiber, glass fiber cloth, glass fabric, glass nonwoven fabric, glass mesh, . The composite sheet according to claim 1, wherein the second sheet comprises a cured product of an acrylic resin-containing composition. The composite sheet according to claim 1, further comprising a barrier layer on one side of the second sheet. Laminating a base film coated with a composition for a second sheet on a matrix impregnated with a reinforcing material, and curing the composition for the second sheet and the matrix,
Before the curing, the composition for the matrix and the second sheet is in a state that is not fully cured,
Wherein the matrix comprises a linear silicone-based rubber.
A method for manufacturing a composite sheet. The method for producing a composite sheet according to claim 11, wherein the composition for the second sheet is cured at a curing rate of 10 to 50% before the curing. The method of producing a composite sheet according to claim 11, wherein the base film comprises a film on which a primer layer is formed. The method of producing a composite sheet according to claim 11, wherein the composition for the second sheet comprises an acrylic resin. A substrate, and a member for an apparatus formed on the substrate,
Wherein the substrate comprises the composite sheet according to any one of claims 1 to 10.

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