KR20220167683A - Optical laminate, substrate for display device, and optical device using the same - Google Patents

Abstract

The present invention relates to an optical laminate in which a base layer, an inorganic deposition layer, a first polyimide resin layer, a first inorganic material layer, a second polyimide resin layer, and a second inorganic material layer are stacked in sequence. The present invention relates to an optical laminate, a substrate for a display device using the same, and an optical device. According to the present invention, excellent heat resistance, dielectric properties and optical properties can be realized by suppressing deformation of a film at high temperatures.

Description

Optical laminate, substrate for display device using the same, and optical device

The present invention relates to an optical laminate capable of realizing excellent heat resistance, dielectric properties and optical properties by suppressing film deformation at high temperature, a substrate for a display device using the same, and an optical device.

The display device market is rapidly changing, focusing on a flat panel display (FPD), which is easy to have a large area and can be thin and lightweight. Such a flat panel display includes a liquid crystal display (LCD), an organic light emitting display (OLED), or an electrophoretic display (EPD).

A rigid type display is manufactured using a glass substrate as a substrate. A display of a flexible type is manufactured using a plastic substrate as a base material.

However, as a substrate of plastic material is applied to a flexible type display, problems such as afterimage restoration appear. In addition, a substrate made of a plastic material has problems in heat resistance, thermal conductivity, and electrical insulation that are inferior to those of a glass substrate.

Nevertheless, research is being actively conducted to apply a plastic substrate, which is light and flexible and has the advantage of being manufactured in a continuous process, to a mobile phone, a notebook PC, and a TV as an alternative to a glass substrate.

Polyimide resins are easy to synthesize, can be manufactured into thin films, and have the advantage of being applicable to high-temperature processes. In line with the trend of light weight and precision of various electronic devices, polyimide resin is widely applied to semiconductor materials as an integrated material. In particular, many studies are being conducted to apply the polyimide resin to a flexible plastic display board requiring light and flexible properties.

An object of the present invention is to provide an optical laminate capable of realizing excellent heat resistance, dielectric properties and optical properties by suppressing film deformation at high temperatures.

In addition, the present invention is to provide a substrate for a display device using the optical laminate, and an optical device.

In order to solve the above problems, in the present specification, the base layer; an inorganic vapor deposition layer formed on the base layer; a first polyimide resin layer formed on the inorganic deposition layer; a first inorganic material layer formed on the first polyimide resin layer; a second polyimide resin layer formed on the first inorganic material layer; and a second inorganic material layer formed on the second polyimide resin layer.

In the present specification, a substrate for a display device including the optical laminate is also provided.

In this specification, an optical device including the optical laminate is also provided.

Hereinafter, an optical laminate according to a specific embodiment of the present invention, a substrate for a display device using the same, and an optical device will be described in more detail.

Unless explicitly stated herein, terminology is used only to refer to specific embodiments and is not intended to limit the present invention.

As used herein, the singular forms also include the plural forms unless the phrases clearly dictate the contrary.

As used herein, the meaning of 'comprising' specifies a particular property, domain, integer, step, operation, element, and/or component, and other particular property, domain, integer, step, operation, element, component, and/or group. does not exclude the presence or addition of

In this specification, terms including ordinal numbers such as 'first' and 'second' are used for the purpose of distinguishing one component from another component, and are not limited by the ordinal number. For example, within the scope of the present invention, a first element may also be termed a second element, and similarly, a second element may be termed a first element.

In the present specification, a (co)polymer refers to a polymer or a copolymer, and the polymer refers to a homopolymer composed of a single repeating unit, and the copolymer refers to a multipolymer containing two or more types of repeating units.

In this specification, examples of substituents are described below, but are not limited thereto.

In this specification, the term "substitution" means that another functional group is bonded instead of a hydrogen atom in a compound, and the position to be substituted is not limited as long as the position where the hydrogen atom is substituted, that is, the position where the substituent can be substituted, and when two or more are substituted , Two or more substituents may be the same as or different from each other.

In this specification, the term "substituted or unsubstituted" means deuterium; halogen group; cyano group; nitro group; hydroxy group; carbonyl group; ester group; imide group; amide group; primary amino group; carboxy group; sulfonic acid group; sulfonamide group; phosphine oxide group; alkoxy group; aryloxy group; Alkyl thioxy group; Arylthioxy group; an alkyl sulfoxy group; aryl sulfoxy groups; silyl group; boron group; an alkyl group; cycloalkyl group; alkenyl group; aryl group; aralkyl group; Aralkenyl group; Alkyl aryl group; an alkoxysilylalkyl group; Arylphosphine group; Or substituted or unsubstituted with one or more substituents selected from the group consisting of a heterocyclic group containing at least one of N, O, and S atoms, or substituted or unsubstituted with two or more substituents linked to each other among the substituents exemplified above. . For example, "a substituent in which two or more substituents are connected" may be a biphenyl group. That is, the biphenyl group may be an aryl group or may be interpreted as a substituent in which two phenyl groups are connected.

, 또는

는 다른 치환기에 연결되는 결합을 의미하고, 직접결합은 L 로 표시되는 부분에 별도의 원자가 존재하지 않은 경우를 의미한다. In this specification,

, or

means a bond connected to another substituent, and a direct bond means a case where no separate atom exists in the part represented by L.

In the present specification, aromatic is a property that satisfies the Huckels Rule, and a case that satisfies all of the following three conditions according to the Huckels Rule can be defined as aromatic.

1) There must be 4n+2 electrons completely conjugated by an empty p-orbital, an unsaturated bond, an unpaired electron pair, etc.

2) 4n+2 electrons must form planar isomers and form a ring structure.

3) All atoms of the ring must be able to participate in conjugation.

In the present specification, the alkyl group is a monovalent functional group derived from an alkane, and may be straight-chain or branched-chain, and the number of carbon atoms of the straight-chain alkyl group is not particularly limited, but is preferably 1 to 20. In addition, the number of carbon atoms of the branched chain alkyl group is 3 to 20. Specific examples of the alkyl group include methyl, ethyl, propyl, n-propyl, isopropyl, butyl, n-butyl, isobutyl, tert-butyl, sec-butyl, 1-methyl-butyl, 1-ethyl-butyl, pentyl, n -pentyl, isopentyl, neopentyl, tert-pentyl, hexyl, n-hexyl, 1-methylpentyl, 2-methylpentyl, 4-methyl-2-pentyl, 3,3-dimethylbutyl, 2-ethylbutyl, heptyl , n-heptyl, 1-methylhexyl, octyl, n-octyl, tert-octyl, 1-methylheptyl, 2-ethylhexyl, 2-propylpentyl, n-nonyl, 2,2-dimethylheptyl, 1-ethyl- propyl, 1,1-dimethyl-propyl, isohexyl, 2-methylpentyl, 4-methylhexyl, 5-methylhexyl, 2,6-dimethylheptan-4-yl, and the like, but is not limited thereto. The alkyl group may be substituted or unsubstituted, and examples of the substituent when substituted are as described above.

In the present specification, a haloalkyl group means a functional group in which a halogen group is substituted for the aforementioned alkyl group, and examples of the halogen group include fluorine, chlorine, bromine, or iodine. The haloalkyl group may be substituted or unsubstituted, and examples of substituents in the case of substitution are as described above.

In the present specification, a multivalent functional group is a residue in which a plurality of hydrogen atoms bonded to any compound are removed, and examples thereof include a divalent functional group, a trivalent functional group, and a tetravalent functional group. For example, a tetravalent functional group derived from cyclobutane refers to a residue in which 4 arbitrary hydrogen atoms bonded to cyclobutane are removed.

In the present specification, the electron-withdrawing group may include at least one selected from the group consisting of a haloalkyl group, a halogen group, a cyano group, a nitro group, a sulfonic acid group, a carbonyl group, and a sulfonyl group, preferably Preferably, it may be a haloalkyl group such as a trifluoromethyl group (-CF ₃ ).

In the present specification, a direct bond or a single bond means that no atom or group of atoms is present at the corresponding position and is connected by a bond line. Specifically, it means the case where no additional atom exists in the part represented by L ₁ and L ₂ in the formula.

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

1. Optical stack

According to one embodiment of the invention, the base layer; an inorganic vapor deposition layer formed on the base layer; a first polyimide resin layer formed on the inorganic deposition layer; a first inorganic material layer formed on the first polyimide resin layer; a second polyimide resin layer formed on the first inorganic material layer; and a second inorganic material layer formed on the second polyimide resin layer.

The present inventors have inserted an inorganic film having excellent dimensional stability at high temperatures between the base layer and the polyimide layer, thereby reducing the disadvantages of the base layer having poor dimensional stability due to expansion at high temperatures, and film at high temperatures of the entire optical laminate. The present invention was completed after confirming through experiments that the thermal, electrical, and optical properties of the conventional optical laminate can be maintained or improved while the deformation can be relatively suppressed.

More specifically, by introducing an inorganic vapor deposition layer on the substrate layer coated with a polyimide double film structure to suppress physical and optical film deformation at high temperatures, a process that requires a high post-heat treatment process such as LTPS rather than oxide-based TFT It is also possible to manufacture a substrate material that can be applied in

In addition, the polyimide layer is composed of a double layer of a first polyimide resin layer and a second polyimide resin layer, a first inorganic material layer is inserted between the first polyimide resin layer and the second polyimide resin layer, and the second A second inorganic material layer is also introduced on the polyimide resin layer, and the first inorganic material layer is inserted between the first polyimide resin layer and the second polyimide resin layer, and the second inorganic material layer is formed on the second polyimide resin layer. It is used to enhance the sealing ability of the polyimide resin layer, which has higher moisture permeability and hygroscopicity than silver glass, and the second inorganic material layer formed on the second polyimide resin layer is formed on the second polyimide resin layer in the display TFT structure. Acting as an applied insulating film, it is possible to reduce electrical influence on the second polyimide resin layer.

Specifically, the optical laminate may include a base layer. The base layer may be used as a support substrate layer of a large-area flexible display. To this end, the base layer may have various thicknesses of 0.01 μm or more and 1000 μm or less.

Examples of the substrate layer are not particularly limited, and a glass substrate, a wafer substrate, a flexible substrate, or a mixture thereof may be used without limitation. As the flexible substrate, any polymer known to be applicable to a substrate of a flexible device may be included without particular limitation. Specific examples include the group consisting of polyethersulfone, polyethylenenaphthalate, polyethyleneterephthalate, polycarbonate, polyimide, polyetherimide, polyamideimide, polyester, polyether amide imide, polyester amide imide and polyarylate. It may include one or more polymer resins selected from, and more preferably may include a polyimide-based resin, and the type of polyimide is not particularly limited.

Preferably, a glass substrate may be used as the base layer.

In addition, the optical laminate may include an inorganic deposition layer formed on the base layer. When a polyimide resin layer is directly laminated on a glass substrate, which is a conventional base layer, there is a problem in that physical deformation such as film lifting or film deformation occurs in the polyimide resin layer while passing through a plurality of heat treatment processes. On the other hand, when the polyimide resin layer is laminated after forming the inorganic vapor deposition layer on the substrate layer, excellent optical and mechanical characteristics are maintained even though film lifting or deformation is reduced by the inorganic vapor deposition layer.

Specifically, by introducing an inorganic vapor deposition layer on the substrate layer in contact with the first polyimide resin layer, the thermal expansion coefficient of the substrate itself is reduced to reduce the level of dimensional change at high temperature (level of expansion or decrease in the thickness direction of the carrier glass) can reduce In particular, in the case of a glass substrate used for the base layer, when high-temperature heat is applied, expansion proceeds in the horizontal direction, and contraction occurs in the vertical direction (thickness direction). At this time, the inorganic deposition layer stacked on the glass substrate can suppress shrinkage in the vertical direction (thickness direction), thereby maximizing dimensional stability and stability of physical properties at high temperatures.

Specifically, the inorganic deposition layer formed on the glass substrate may include at least one selected from the group consisting of silicon-based materials and indium tin oxide. That is, the inorganic deposition layer formed on the glass substrate may include one type of silicon-based material, one type of indium tin oxide, or a mixture of two or more types thereof.

The silicon-based material may include one selected from the group consisting of amorphous silicon, silicon oxide, and silicon nitride. That is, the silicon-based material may include one kind of amorphous silicon, one kind of silicon oxide, one kind of silicon nitride, or a mixture of two or more kinds thereof.

More preferably, the inorganic deposition layer formed on the glass substrate may include a silicon-based material.

The inorganic vapor deposition layer formed on the base layer may be formed on one side or both sides of the base layer.

In the formation of the inorganic deposition layer, a conventional inorganic film formation method in the technical field to which the present invention belongs, such as chemical vapor deposition (CVD) and physical vapor deposition (PVD), may be applied. In particular, the specific method of the chemical vapor deposition method is not particularly limited, but, for example, plasma enhanced chemical vapor deposition (PECVD) or high-density plasma enhanced chemical vapor deposition (HDPCVD) may be applied.

In addition, the optical laminate may include a first polyimide resin layer formed on the inorganic deposition layer. As the first polyimide resin layer is included, high resistance characteristics are realized due to the wide polymer chain spacing of the first polyimide resin layer, and electrical influence is reduced, improving afterimage when applied as a substrate to a display device or a flexible display device can help

In addition, as the first polyimide resin layer included in the substrate for the display device or flexible display device has a low yellowness, when applied as a substrate for a display device or flexible display device, excellent light transmittance and low yellowness optical properties can be realized. Specifically, the transmittance at 470 nm is improved and the saturation charge voltage half-life is increased, so that low dielectric properties can be implemented.

Specifically, the yellow index of the first polyimide resin layer may be 20 or less, or 15 or 12 or less. In addition, the yellow index of the first polyimide resin layer may be 0.1 or more, or 1 or more. In addition, the yellow index of the first polyimide resin layer may be 0.1 to 20, or 0.1 to 15, or 0.1 to 12, or 1 to 20, or 1 to 15, or 1 to 12. The yellow index may be measured using a color meter (GRETAGMACBETH Color-Eye 7000A) for a polyimide resin layer specimen having a thickness of 5 μm to 15 μm or 9 μm to 11 μm.

In addition, the light transmittance of the first polyimide resin layer at a wavelength of 550 nm may be 85% or more, or 100% or less, or 95% or less, or 85% to 100%, or 85% to 95%. The light transmittance may be measured using a UV-vis spectroscopy (Agillent, UV 8453) device for a polyimide resin layer specimen having a thickness of 5 μm to 15 μm or 9 μm to 11 μm. When the light transmittance of the first polyimide resin layer at a wavelength of 550 nm is reduced to less than 85%, there is a risk of poor transparency.

In addition, the light transmittance of the first polyimide resin layer at a wavelength of 470 nm may be 75% or more, or 100% or less, or 75% to 100%. The light transmittance may be measured using a UV-vis spectroscopy (Agillent, UV 8453) device for a polyimide resin layer specimen having a thickness of 5 μm to 15 μm or 9 μm to 11 μm. When the light transmittance of the first polyimide resin layer at a wavelength of 470 nm is reduced to less than 65%, there is a risk of poor transparency.

In addition, the maximum tensile strength of the first polyimide resin layer is 140 MPa or more, or 150 MPa or more, or 155 MPa or more, or 200 MPa or less, or 180 MPa or less, or 140 MPa to 200 MPa or less, or 140 MPa to 200 MPa or less 180 MPa or less, or 150 MPa to 200 MPa or less, or 150 MPa to 180 MPa or less, or 155 MPa to 200 MPa or less, or 155 MPa to 180 MPa or less. The maximum tensile strength is measured by the maximum stress at the time of rupture during tension according to the ASTM D 638 measurement method with a universal testing machine (UTM) for a polyimide resin layer specimen having a thickness of 5 μm to 15 μm or 9 μm to 11 μm. can do. When the maximum tensile strength of the first polyimide resin layer is reduced to less than 140 MPa, there is a concern that durability of the optical laminate may deteriorate.

In addition, the saturation charge voltage half-life of the first polyimide resin layer may be 500 seconds or more, or 520 seconds or more, or 2000 seconds or less, or 500 seconds to 2000 seconds, or 520 seconds to 2000 seconds. The saturation charge voltage half-life may be measured according to the JIS L 1094 standard using a Honestmeter device for a polyimide resin layer specimen having a thickness of 5 μm to 15 μm or 9 μm to 11 μm. If the saturation charge voltage half-life of the first polyimide resin layer is reduced to less than 500 seconds, it is difficult to implement low dielectric characteristics.

More specifically, the first polyimide resin layer may include a polyimide resin including a repeating unit derived from diamine in which an electron withdrawing functional group is substituted. In the present specification, the polyimide resin means including both polyimide and polyamic acid and polyamic acid ester, which are precursor polymers thereof. That is, the polyimide resin may include at least one selected from the group consisting of a polyamic acid repeating unit, a polyamic acid ester repeating unit, and a polyimide repeating unit. That is, the polyimide resin may include one type of polyamic acid repeating unit, one type of polyamic acid ester repeating unit, one type of polyimide repeating unit, or a copolymer in which two or more types of repeating units thereof are mixed.

At least one repeating unit selected from the group consisting of the polyamic acid repeating unit, the polyamic acid ester repeating unit, and the polyimide repeating unit may form the main chain of the polyimide resin.

More specifically, the first polyimide resin layer may include a polyimide resin including a repeating unit represented by Chemical Formula 1 below.

[Formula 1]

In Chemical Formula 1, X ₁ is an aromatic tetravalent functional group, and Y ₁ is an aromatic divalent functional group substituted with at least one electron withdrawing functional group.

The aromatic divalent functional group in which at least one electron withdrawing functional group of Y ₁ is substituted may include a divalent functional group represented by Chemical Formula 2 below.

[Formula 2]

In Formula 2, Q ₁ and Q ₂ are the same as or different from each other, and each independently represents an electron withdrawing functional group, n and m are the same as or different from each other, and each independently represents an integer of 1 or more and 4 or less.

As an example, the divalent functional group represented by Chemical Formula 2 is represented by the following Chemical Formula 2-1 derived from 2,2'-bis (trifluoromethyl) benzidine (TFMB) Functional groups can be mentioned.

[Formula 2-1]

When the functional group represented by Chemical Formula 2 is included in Y ₁ , an electron withdrawing functional group such as a trifluoromethyl group (-CF ₃ ) capable of imparting an electron withdrawing effect is introduced as a substituent, which is present in the imide chain. By suppressing the formation of charge transfer complex (CTC) of Pi-electrons, transparency can be secured and excellent optical properties can be realized.

That is, packing within the polyimide structure or between chains can be reduced, and electrical interactions between color sources can be weakened due to steric hindrance and electrical effects, resulting in high transparency in the visible light region.

In Formula 1, X ₁ is an aromatic tetravalent functional group having 24 or more, or 30 or less carbon atoms or 24 to 30 carbon atoms, an aromatic tetravalent functional group having 9 or more, or 15 or less carbon atoms, or 9 to 15 carbon atoms, or these is one of the mixtures, wherein X ₁ is a functional group derived from a tetracarboxylic dianhydride compound used in synthesizing a polyimide resin.

That is, in the repeating unit represented by Chemical Formula 1, X ₁ is a first repeating unit having 24 or more, or 30 or less carbon atoms, or an aromatic tetravalent functional group having 24 to 30 carbon atoms, X ₁ is 9 or more carbon atoms, or It may include 15 or less, or 9 to 15 aromatic tetravalent functional groups of the second repeating unit, or all of them.

When the first repeating unit and the second repeating unit are included together, the mole ratio of the first repeating unit to 100 moles of the second repeating unit is 10 moles or more, or 90 moles or less, or 10 to 90 moles. can An optical laminate in which the first polyimide resin layer synthesized from the polyimide resin is laminated on the inorganic deposition layer on the substrate layer within the above numerical range may simultaneously satisfy excellent heat resistance, dielectric properties, and optical properties.

When the multi-ring-containing aromatic 4 having 24 or more carbon atoms includes a functional group in X ₁ , an asymmetric structure in which steric hindrance is increased due to the multi-ring is introduced into the polyimide chain structure, thereby relieving heat-induced deformation and improving heat resistance. It is possible to improve, and preferably, it is possible to implement a low phase difference by reducing the difference in refractive index between the plane direction and the thickness direction.

More specifically, the tetravalent aromatic functional group having 24 or more carbon atoms containing a polycyclic ring of X ₁ may include a tetravalent functional group represented by Chemical Formula 3 below.

[Formula 3]

In Chemical Formula 3, Ar is a polycyclic aromatic divalent functional group. The multi-cyclic aromatic divalent functional group is a divalent functional group derived from a polycyclic aromatic hydrocarbon compound or a derivative compound thereof, and may include a fluorenylene group. The derivative compound includes all compounds in which one or more substituents are introduced or carbon atoms are replaced with heteroatoms.

More specifically, in Ar of Chemical Formula 3, the multi-cyclic aromatic divalent functional group may include a fused cyclic divalent functional group containing at least two or more aromatic ring compounds. That is, the multi-cyclic aromatic divalent functional group contains at least two or more aromatic ring compounds in the functional group structure, and the functional group may have a fused ring structure.

The aromatic ring compound may include an arene compound containing at least one benzene ring or a hetero arene compound in which a carbon atom in the arene compound is replaced with a hetero atom.

The aromatic ring compound may contain at least two or more in a polycyclic aromatic divalent functional group, and each of the two or more aromatic ring compounds may form a bonded ring directly or form a bonded ring through another ring structure. For example, when two benzene rings are each bonded to a cycloalkyl ring structure, it can be defined that two benzene rings form a bonded ring through a cycloalkyl ring.

The fused cyclic divalent functional group containing at least two or more aromatic ring compounds is a divalent functional group derived from a fused ring compound containing at least two or more aromatic ring compounds or a derivative compound thereof, wherein the derivative compound has one or more substituents introduced therein. or a compound in which a carbon atom is replaced with a heteroatom.

As an example, the tetravalent functional group represented by Formula 3 is derived from 9,9-bis (3,4-dicarboxyphenyl) fluorene dianhydride. and functional groups represented by Chemical Formula 3-1.

[Formula 3-1]

Meanwhile, the tetravalent aromatic functional group having 9 to 15 carbon atoms may include a tetravalent functional group represented by Chemical Formula 4 below.

[Formula 4]

In Formula 4, L is a single bond, -O-, -CO-, -COO-, -S-, -SO-, -SO ₂ -, -CR ₁ R ₂ -, -(CH ₂ ) _t -, -O(CH ₂ ) _t O-, -COO(CH ₂ ) _t OCO-, -CONH-, any one selected from the group consisting of phenylene or a combination thereof, wherein R ₁ and R ₂ are each independently hydrogen, an alkyl group having 1 to 10 carbon atoms, or a haloalkyl group having 1 to 10 carbon atoms, and t is an integer of 1 to 10.

As an example, the tetravalent functional group represented by Chemical Formula 4 is derived from 3,3',4,4'-biphenyltetracarboxylic dianhydride (Formula 4-1 below) The functional group represented by can be mentioned.

[Formula 4-1]

More specifically, the polyimide-based resin is a reaction between a terminal anhydride group (-OC-O-CO-) of a tetracarboxylic dianhydride and a terminal amino group (-NH ₂ ) of an aromatic diamine substituted with at least one electron withdrawing functional group. A bond may be formed between the nitrogen atom of the amino group and the carbon atom of the anhydride group.

In addition, the polyimide resin included in the first polyimide resin layer may further include a repeating unit represented by Chemical Formula 5 below.

[Formula 5]

In Chemical Formula 5, X ₂ is an aromatic divalent functional group, and Y ₂ is an unsubstituted aromatic divalent functional group. X ₂ in Formula 5 is the same as the description for X ₁ in Formula 1 above.

Meanwhile, the unsubstituted aromatic divalent functional group of Y ₂ may include a functional group represented by the following Chemical Formula 6 derived from para-phenylene diamine.

[Formula 6]

Since the repeating unit represented by Chemical Formula 5 may have mechanical properties and excellent heat resistance at high temperatures, when the first polyimide resin layer includes the repeating unit represented by Chemical Formula 5, the optical laminate of one embodiment may have 430 Even through a high-temperature process of °C or higher, deformation and denaturation due to heat can be significantly reduced.

Meanwhile, the polyimide resin included in the first polyimide resin layer may include a cured material cured at a temperature of 400 °C or higher. The cured product refers to a material obtained through a curing process of the polyimide precursor composition, and the curing process may be performed at a temperature of 400 °C or more, 500 °C or less, or 400 °C to 500 °C.

More specifically, an example of a method of synthesizing the first polyimide resin layer is not particularly limited, and for example, forming a coating film by applying a polyimide precursor composition to a base layer on which an inorganic deposition layer is formed (step 1) ; drying the coating film (step 2); A manufacturing method including a step (step 3) of curing the dried coating film by heat treatment may be used.

Step 1 is a step of forming a coating film by applying the polyimide precursor composition described above to the base layer on which the inorganic deposition layer is formed. A method of applying the polyimide precursor composition to the substrate is not particularly limited, and for example, screen printing, offset printing, flexographic printing, inkjet, or the like may be used.

And, the polyimide precursor composition may be dissolved or dispersed in an organic solvent. In the case of having such a form, for example, when a polyimide-based resin is synthesized in an organic solvent, the solution may be the obtained reaction solution itself or a solution obtained by diluting this reaction solution with another solvent. Moreover, when polyimide-type resin was obtained as powder, what was made into the solution by dissolving this in the organic solvent may be used.

Specific examples of the organic solvent include toluene, N,N-dimethylformamide, N,N-dimethylacetamide, N-methyl-2-pyrrolidone, N-methylcaprolactam, 2-pyrrolidone, N-ethyl Pyrrolidone, N-vinylpyrrolidone, dimethylsulfoxide, tetramethylurea, pyridine, dimethylsulfone, hexamethylsulfoxide, gamma-butyrolactone, 3-methoxy-N,N-dimethylpropanamide, 3- Ethoxy-N,N-dimethylpropanamide, 3-butoxy-N,N-dimethylpropanamide, 1,3-dimethyl-imidazolidinone, ethyl amyl ketone, methyl nonyl ketone, methyl ethyl ketone, methyl isoa Mil ketone, methyl isopropyl ketone, cyclohexanone, ethylene carbonate, propylene carbonate, diglyme, 4-hydroxy-4-methyl-2-pentanone, ethylene glycol monomethyl ether, ethylene glycol monomethyl ether acetate, ethylene glycol Monoethyl Ether, Ethylene Glycol Monoethyl Ether Acetate, Ethylene Glycol Monopropyl Ether, Ethylene Glycol Monopropyl Ether Acetate, Ethylene Glycol Monoisopropyl Ether, Ethylene Glycol Monoisopropyl Ether Acetate, Ethylene Glycol Monobutyl Ether, Ethylene Glycol Monobutyl Ether Acetate etc. are mentioned. These may be used alone or in combination.

The polyimide precursor composition may include a solid content in an amount to have an appropriate viscosity in consideration of processability such as coatability during the film forming process. For example, the content of the composition is adjusted so that the total resin content is 5 wt% or more, or 25 wt% or less, or 20 wt% or less, or 5 wt% to 25 wt%, or 5 wt% to 20 wt%. It can be, or it can be adjusted to 5% by weight or more.

In addition, the polyimide precursor composition may further include other components in addition to the organic solvent. As a non-limiting example, when the resin composition containing the polyimide-based resin is applied, the film thickness uniformity or surface smoothness may be improved, or adhesion to a substrate may be improved, or permittivity or conductivity may be changed. Alternatively, additives capable of increasing compaction may be additionally included. Such additives may include surfactants, silane-based compounds, dielectric or cross-linkable compounds, and the like.

Step 2 is a step of drying the coating film formed by applying the polyimide precursor composition to the substrate layer on which the inorganic deposition layer is formed.

The drying step of the coating film may be performed by a heating means such as a hot plate, a hot air circulation furnace, an infrared furnace, or the like, and may be performed at 50° C. or higher, or 150° C. or lower, or 100° C. or lower, or 50° C. to 150° C., or 50° C. to 50° C. It can be carried out at a temperature of 100 °C.

Step 3 is a step of curing the dried coating film by heat treatment. In this case, the heat treatment may be performed by a heating means such as a hot plate, a hot air circulation furnace, an infrared furnace, or the like, and may be performed at a temperature of 400° C. or higher, 500° C. or lower, or 400° C. to 500° C.

In addition, the optical laminate may include a first inorganic material layer formed on the first polyimide resin layer. The first inorganic material layer may be positioned between the first polyimide resin layer and the second polyimide resin layer to block air and moisture, thereby providing an optical laminate having excellent device stability.

The first inorganic material layer is at least one inorganic material selected from the group consisting of silicon oxide (SiOx), silicon nitride (SiNx), silicon oxynitride (SiON), aluminum oxide (AlO), and aluminum oxynitride (AlON) can include

The thickness of the first inorganic material layer is not particularly limited, and may be applied without limitation within a range of 1000 Å to 7000 Å. However, as a limited example, the first inorganic material layer may have a thickness of 100 nm or more, or 400 nm or more, or 700 nm or less, or 100 nm to 700 nm, or 400 nm to 700 nm.

For forming the first inorganic material layer, a conventional inorganic film forming method in the art, such as chemical vapor deposition (CVD) or physical vapor deposition (PVD), may be applied. In particular, the specific method of the chemical vapor deposition method is not particularly limited, but, for example, plasma enhanced chemical vapor deposition (PECVD) or high-density plasma enhanced chemical vapor deposition (HDPCVD) may be applied.

In addition, the optical laminate may include a second polyimide resin layer formed on the first inorganic material layer. A composition of the second polyimide resin layer is the same as that of the first polyimide resin layer.

Meanwhile, the thickness of the first polyimide resin layer may be greater than the thickness of the second polyimide resin layer. Specifically, based on the thickness of the first polyimide resin layer of 1 μm, the thickness ratio of the second polyimide resin layer may be 0.3 μm to 0.7 μm. Accordingly, in terms of physical strength by thickness, structural stability during lamination may be improved, and moisture permeation resistance may also be improved. When the thickness ratio of the second polyimide resin layer is excessively reduced to less than 0.3 μm based on the thickness of the first polyimide resin layer of 1 μm, the structural stability and moisture permeation resistance of the second polyimide resin layer cannot be sufficiently implemented. It is difficult, and when the thickness ratio of the second polyimide resin layer excessively increases to more than 0.7 μm based on the thickness of the first polyimide resin layer of 1 μm, the increase in the thickness of the polyimide resin layer reduces permeability and increases film lifting problem may arise.

For example, in one embodiment, the first polyimide resin layer has a thickness of 1 μm to 15 μm, or 2 μm to 15 μm, or 6 μm to 15 μm, or 1 μm to 10 μm, or 2 μm to 10 μm. , or has a thickness of 6 μm to 10 μm, and the second polyimide resin layer may have a thickness of 0.5 μm to 6 μm, or 1 μm to 6 μm, or 3 μm to 6 μm.

In addition, the optical laminate may include a second inorganic material layer formed on the second polyimide resin layer. The second inorganic material layer is located on the second polyimide resin layer, blocks air and moisture, can realize excellent device stability, and minimizes the electrical effect of the thin film transistor, so it is a high-quality display device or flexible An optical laminate suitable for a device for a display device can be provided.

That is, the second inorganic material layer may act as an insulating film applied on the second polyimide resin layer in the display TFT structure, thereby reducing electrical influence on the second polyimide resin layer.

The second inorganic material layer is at least one inorganic material selected from the group consisting of silicon oxide (SiOx), silicon nitride (SiNx), silicon oxynitride (SiON), aluminum oxide (AlO), and aluminum oxynitride (AlON) can include

For forming the second inorganic material layer, a conventional inorganic film forming method in the art, such as chemical vapor deposition (CVD) or physical vapor deposition (PVD), may be applied. In particular, the specific method of the chemical vapor deposition method is not particularly limited, but, for example, plasma enhanced chemical vapor deposition (PECVD) or high-density plasma enhanced chemical vapor deposition (HDPCVD) may be applied.

The thickness of the second inorganic material layer is not particularly limited, and may be applied without limitation within a range of 1000 Å to 7000 Å. However, as a limited example, the thickness of the first inorganic material layer may be greater than the thickness of the second inorganic material layer. Specifically, based on the thickness of the first inorganic material layer of 1 μm, the thickness ratio of the second inorganic material layer may be 0.3 μm to 0.7 μm. This is due to the difference in the structure in which the first inorganic material layer is laminated between the first polyimide resin layer and the second polyimide resin layer, and the second inorganic material layer is laminated only on the second polyimide resin layer. will be.

For example, the first inorganic material layer may have a thickness of 100 nm or more, or 400 nm or more, or 700 nm or less, or 100 nm to 700 nm, or 400 nm to 700 nm. Also, the second inorganic material layer may have a thickness of 100 nm or more, or 700 nm or less, or 400 nm or less, or 100 nm to 700 nm, or 100 nm to 400 nm.

The optical laminate according to the present invention can exhibit excellent colorless and transparent properties while maintaining properties such as heat resistance and mechanical strength due to a rigid structure, and can be used as a device substrate, a cover substrate for a display, an optical film, It can be used in various fields such as a circuit board, an integrated circuit (IC) package, an adhesive film, a multi-layer flexible printed circuit (FRC), a tape, a touch panel, and a protective film for an optical disk.

On the other hand, according to the following equation of the optical laminate, the change in yellowness before and after the heat treatment process at 430 ° C is 60 or less, or 10 or less, or 8 or less, or 0 or more, or 0 to 60, or 0 to 10, or 0 to 8 days.

[mathematical expression]

Yellowness change before and after 430 ° C post-heat treatment (ΔYI) = (Yellowness of optical laminate after 430 ° C post-heat treatment (YI ₁ )) - (Yellowness of optical laminate before 430 ° C post-heat treatment (YI _{0 )} ))

In the above equation, as an example of the 430 ° C post-heat treatment step, the optical laminate may be heated to 430 ° C for 2 hours, subjected to an isothermal temperature of 430 ° C for 2 hours, and then cooled to 50 ° C for 2 hours. there is.

If the change in yellowness of the optical laminate before and after the heat treatment process at 430 ° C is excessively increased to more than 60, or more than 10, or more than 8 according to the above equation, the optical deformation of the laminate becomes severe at a high temperature of 400 ° C. or more, resulting in oxide-based There is a limitation that it is difficult to proceed with a process that requires a high post-heat treatment process such as LTPS rather than TFT.

On the other hand, included in the optical laminate, the base layer; and an inorganic vapor deposition layer, a first heating step was performed from 50 ° C to 430 ° C at a temperature raising rate of 5 ° C / min, and then a cooling step was performed to 80 ° C at a cooling rate of 4 ° C / min. After that, the vertical thermal expansion level (dimension change) when the second heating step is performed at a temperature raising rate of 5 ° C / min to 480 ° C is -2 μm or more and 2 μm or less, more preferably -1 μm or more and 1 μm or less. there is.

An example of a method for measuring the dimension change is a thermomechanical analyzer (TMA), and the specific equipment and measurement method of the thermomechanical analysis method are related to the thermomechanical analysis of existing polymers. Content can be applied without restrictions.

When the vertical direction thermal expansion level (dimension change) is excessively increased to less than -2 ㎛ or more than 2 ㎛, as the physical deformation of the laminate is severe at a high temperature of 400 ℃ or more and the dimensional stability is poor, the oxide-based TFT There is a limitation that it is difficult to proceed with a process that requires a high post-heat treatment process such as LTPS.

2. Substrates for display devices

Meanwhile, according to another embodiment of the present invention, a substrate for a display device including the optical laminate of one embodiment may be provided. Information regarding the optical laminate may include all of the above-described information in the embodiment.

A display device including the substrate is a liquid crystal display device (LCD), an organic light emitting diode (OLED), a flexible display, or a rollable display or foldable display ), etc., but is not limited thereto.

The display device may have various structures depending on application fields and specific shapes. For example, it may have a structure including a cover plastic window, a touch panel, a polarizer, a barrier film, a light emitting device (OLED device, etc.), a transparent substrate, and the like. there is.

The optical laminate of one embodiment described above may be used for various purposes such as a substrate, an external protective film, or a cover window in various display devices, and more specifically, may be applied as a substrate.

For example, the display device substrate may have a structure in which a device protection layer, a transparent electrode layer, a silicon oxide layer, an optical laminate, a silicon oxide layer, and a hard coating layer are sequentially stacked.

The optical laminate may include a silicon oxide layer formed between a transparent polyimide-based resin film and a cured layer in order to further improve solvent resistance, water permeability and optical properties, and the silicon oxide layer is polysilla It may be produced by hardening a cup.

Specifically, the silicon oxide layer is formed by coating and drying a solution containing polysilazane before forming a coating layer on at least one surface of the transparent polyimide-based resin film, and then curing the coated polysilazane. it could be

The substrate for a display device according to the present invention includes the above-described device protection layer, thereby providing a transparent polyimide cover substrate having excellent bending characteristics and impact resistance, as well as solvent resistance, optical characteristics, moisture permeability and scratch resistance. there is.

3. Optics

Meanwhile, according to another embodiment of the present invention, an optical device including the optical laminate of one embodiment may be provided. Information regarding the optical laminate may include all of the above-described information in the embodiment.

The optical device may include all kinds of devices using properties implemented by light, and examples thereof include a display device. Specific examples of the display device include a liquid crystal display device (LCD), an organic light emitting diode (OLED), a flexible display, or a rollable display or foldable display and the like, but are not limited thereto.

The optical device may have various structures depending on application fields and specific shapes. For example, it may have a structure including a cover plastic window, a touch panel, a polarizer, a barrier film, a light emitting device (OLED device, etc.), a transparent substrate, and the like. there is.

The optical laminate of one embodiment described above may be used for various purposes such as a substrate, an external protective film, or a cover window in various optical devices, and more specifically, may be applied to a substrate.

According to the present invention, an optical laminate capable of suppressing film deformation at high temperature and realizing excellent heat resistance, dielectric properties and optical properties, a substrate for a display device using the same, and an optical device can be provided.

The invention is explained in more detail in the following examples. However, the following examples are merely illustrative of the present invention, and the contents of the present invention are not limited by the following examples.

<Preparation Example: Preparation of Polyimide Precursor Composition>

Preparation Example 1

While slowly passing nitrogen into a 500 mL 4-neck round bottom flask (reactor) equipped with a stirrer, nitrogen injector, dropping funnel, temperature controller, and condenser, 100 g of diethylacetamide (DEAC) was charged, and 33 mmole of para -Phenylene diamine (p-phenylene diamine, PDA) and 33 mmole of 2,2'-bis(trifluoromethyl)benzidine (2,2'-Bis(trifluoromethyl)benzidine, TFMB) were added and completely dissolved.

While maintaining the temperature of this solution at room temperature, 51 mmole of 3,3',4,4'-biphenyltetracarboxylic dianhydride (3,3',4,4'-biphenyltetracarboxylic dianhydride, BPDA) and 15 mmol of 9,9-bis (3,4-dicarboxyphenyl) fluorene dianhydride (9,9-Bis (3,4-dicarboxyphenyl) fluorene Dianhydride, BPAF) was added together with 100 g of DEAC and kept for 48 hours. After stirring and dilution, a polyimide precursor composition P-1 (13% by weight solid content) was obtained.

Reference Manufacturing Example 1

While slowly passing nitrogen into a 500 mL 4-neck round bottom flask (reactor) equipped with a stirrer, nitrogen injector, dropping funnel, temperature controller, and condenser, 200 g of N-methyl-2-pyrrolidone was charged and , After adjusting the temperature of the reactor to 40 ℃, 133 mmole of para-phenylene diamine (p-phenylene diamine, PDA) was added and completely dissolved.

While maintaining the temperature of this solution at 40 ° C., 132 mmole of 3,3',4,4'-biphenyltetracarboxylic dianhydride (BPDA) was added to the reactor. ) was added with 120 g of N-methyl-2-pyrrolidone and stirred and diluted for 48 hours to obtain a polyimide precursor composition Q-1 (11% by weight solid content).

<Example: Manufacture of Optical Laminate>

Example 1

An inorganic deposition layer (SiO ₂ , thickness 5,000 Å) was formed on a glass substrate (thickness: 500 μm) by plasma chemical vapor deposition.

The polyimide precursor composition P-1 according to Preparation Example 1 was spin-coated on the inorganic deposition layer. The glass substrate coated with the polyimide precursor composition was placed in an oven, heated to 470 ° C. at 3 ° C./min, and maintained at 470 ° C. for 10 minutes to form a first polyimide resin layer (thickness: 10 ± 2 μm). .

A first inorganic film layer (SiO ₂ , thickness of 5,000 Å) was formed on the first polyimide resin layer by plasma enhanced chemical vapor deposition.

After spin-coating the polyamide precursor composition P-1 according to Preparation Example 1 on the first inorganic film layer, putting it in an oven and heating it at 3 °C/min to 470 °C, maintaining the temperature for 10 minutes at 470 °C to form a second A polyimide resin layer (thickness of 6 μm) was formed.

Thereafter, a second inorganic film layer (SiO ₂ , thickness of 3,000 Å) was formed on the second polyimide resin layer by a plasma enhanced chemical vapor deposition method to prepare an optical laminate.

Example 2

An optical laminate was manufactured in the same manner as in Example 1, except that an inorganic deposition layer (SiN _x , thickness of 3,000 Å) was used as the inorganic deposition layer.

Example 3

An optical laminate was manufactured in the same manner as in Example 1, except that an inorganic deposition layer (amorphous Si, thickness: 500 Å) was used as the inorganic deposition layer.

Example 4

An optical laminate was manufactured in the same manner as in Example 1, except that an inorganic deposition layer (indium tin oxide (ITO), thickness 5,000 Å) by physical vapor deposition was used as the inorganic deposition layer.

<Comparative Example: Manufacture of Optical Laminate>

Comparative Example 1

An optical laminate was manufactured in the same manner as in Example 1, except that the inorganic deposition layer (SiO ₂ , thickness 5,000 Å) was not present.

<Reference Example: Manufacture of Optical Laminate>

Reference example 1

An optical laminate was manufactured in the same manner as in Comparative Example 1, except that the polyimide precursor composition Q-1 according to Reference Preparation Example 1 was used instead of the polyimide precursor composition P-1 according to Preparation Example 1.

<Experimental Example 1>

After forming the first polyimide resin layer on the lower substrate, the lower substrate was peeled off to prepare a polyimide specimen, and the physical properties were measured according to the following method, and the results are shown in Table 1.

1. Coefficient of Thermal Expansion (CTE)

After preparing the specimen in a size of 5 mm x 20 mm, the sample was loaded using an accessory. The actual measured length of the laminate was set to 16 mm. Thermal expansion when cooling is performed at a cooling rate of 4 ℃/min after setting the pulling force to 0.02N and performing the first heating process at a heating rate of 5 ℃/min in the temperature range of 100 ℃ or more and 430 ℃ or less The change pattern was measured by TMA (Q400 from TA). In addition, in Table 1 below, the thermal expansion change pattern in the first heating process was recorded.

2. Saturation voltage and half-life

The saturation charge voltage of the specimen was measured using a SHISHIDO ELECTROSTATIC H-0110 Honestmeter in accordance with the JIS L 1094 standard measurement method at a temperature of 25 °C and a humidity of 40 to 50%.

Specifically, the voltage applied to the specimen was 10 kV, the distance from the tip of the needle electrode of the application part to the surface of the rotating disc was adjusted to 20 mm, and the distance from the electrode plate of the receiving part to the surface of the rotating disc was adjusted to 15 mm. The applied voltage of 10 kV was started while rotating the turntable, the application was finished after 100 seconds, and the time until the charged voltage was attenuated to 1/2 was measured while rotating the turntable in that state. The half-life was obtained by measuring the time from when the high voltage application was cut off to when the potential value decreased by 50% of the saturation charge voltage value.

3. Transmittance

Transmittance (T) of the specimen to light of 470 nm and 550 nm wavelengths was measured using a UV-vis spectroscopy (Agillent, UV 8453) device.

4. Ultimate tensile strength

UTM (Universal testing machine) was measured according to the ASTM D 638 measurement method as the maximum tensile strength at the time of rupture in tension.

5. Yellowness

Using a color meter (GRETAGMACBETH Color-Eye 7000A), the yellowness of the specimen was measured.

division Polyimide precursor composition Board CTE
(ppm/℃) saturation voltage
(kV) half-life (seconds) Transmittance (%) ultimate tensile strength
(MPa) YI 470 nm 550 nm Comparative Example 1 Preparation Example 1 glass substrate 83 2.36 737 88.4 80.7 134.7 11.6 Example 1 Preparation Example 1 SiO ₂ Deposited Glass Substrate 92 2.16 579 79.8 90.5 173.5 10.2 Example 2 Preparation Example 1 SiN _x deposition glass substrate 182 2.12 529 82.2 87.8 167.1 10.7 Example 3 Preparation Example 1 Amorphous Si deposition glass substrate 83 2.03 over 1000 78.8 85.3 160.7 11.3 Example 4 Preparation Example 1 ITO-deposited glass substrate 90 2.11 over 1000 82.3 87.3 157.3 10.2 Reference example 1 Reference Manufacturing Example 1 glass substrate 3 2.19 224 70.7 81.0 180.5 27.9

As shown in Table 1, it was confirmed that the optical laminate of the example using the glass substrate on which the inorganic material was deposited exhibited equivalent or superior characteristics in thermal, optical, and mechanical properties compared to the comparative example using the glass substrate.

<Experimental Example 2>

With respect to the optical laminates obtained in the above Examples and Comparative Examples, physical properties were measured by the following method, and the results are shown in Table 2.

6. Yellowness before and after 430 ℃ post heat treatment

After the post-heat treatment process (heating to 430 ° C. for 2 hours, passing through 430 ° C. isothermal temperature for 2 hours, and then cooling to 50 ° C. for 2 hours) with respect to the optical laminate, the first polyimide number included in the optical laminate The yellowness of the stratum was measured using a color meter (GRETAGMACBETH's Color-Eye 7000A).

Then, the yellowness change before and after the 430 ° C post-heat treatment was calculated by the following equation.

[mathematical expression]

Yellowness change before and after 430 ° C post-heat treatment (ΔYI) = (Yellowness of optical laminate after 430 ° C post-heat treatment (YI ₁ )) - (Yellowness of optical laminate before 430 ° C post-heat treatment (YI _{0 )} ))

7. High temperature dimensional stability

Included in the optical laminate, the substrate layer; With respect to the laminate composed of; and an inorganic deposition layer, after preparing a specimen in a size of 5 mm x 5 mm, a first heating process was performed from 50 ° C. to 430 ° C. at a temperature raising rate of 5 ° C./min, and then 4 ° C./min. After the cooling process was performed to 80 ℃ at a cooling rate of min, the thermal expansion level (dimension change) in the vertical direction (thickness direction of the specimen) when the second heating process was performed at a heating rate of 5 ℃ / min to 480 ℃ was TMA ( It was measured by TA's Q400) expansion mode.

And, the degree of high-temperature dimensional stability was evaluated according to the following criteria.

Excellent: Dimensional change is as small as -1 ㎛ or more and 1 ㎛ or less, excellent in high-temperature dimensional stability

Defective: The dimension change is less than -2 ㎛ and larger than 2 ㎛, so the dimensional stability at high temperature is poor.

8. The first occurrence of moxibustion

Immediately after the manufacturing of the optical laminate and post-heat treatment of each of the following entire processes 1 to 6, the time point at which film lifting was observed with the naked eye (the first time of film lifting) was confirmed for the laminate obtained in each step. .

Process 1) Forming an inorganic vapor deposition layer on the substrate layer

Step 2) Forming a first polyimide resin layer on the inorganic vapor deposition layer

Step 3) Forming a first inorganic material layer on the first polyimide resin layer

Step 4) Forming a second polyimide resin layer on the first inorganic material layer

Step 5) Forming a second inorganic material layer on the second polyimide resin layer

Step 6) Post heat treatment of the optical laminate (heating to 430 ° C for 2 hours, passing through an isothermal temperature of 430 ° C for 2 hours, and then cooling to 50 ° C for 2 hours)

division Polyimide precursor composition Board YI ₀ YI ₁ △YI high temperature dimensional stability First occurrence of moxibustion Comparative Example 1 Preparation Example 1 glass substrate 20.0 85.8 65.8 error Process 4) Example 1 Preparation Example 1 SiO ₂ Deposited Glass Substrate 19.4 26.7 7.3 Great doesn't exist Example 2 Preparation Example 1 SiN _x deposition glass substrate 13.5 17.2 3.7 Great doesn't exist Example 3 Preparation Example 1 Amorphous Si deposition glass substrate 15.6 15.6 0 Great doesn't exist Example 4 Preparation Example 1 ITO-deposited glass substrate 17.2 74.2 57.0 error Process 6) Reference example 1 Reference Manufacturing Example 1 glass substrate 47.2 53.0 5.8 error doesn't exist

As shown in Table 2, in the optical laminate of the example using the inorganic material-deposited glass substrate, no film lifting occurred visually during the process of manufacturing the optical laminate before post-heat treatment, and the yellow color before and after the post-heat treatment process at 430 ° C. The index change amount (ΔYI) was measured lower than that of the comparative example. In particular, the optical laminates of Examples 1 to 3 had a TMA expansion level (dimension change) at high temperatures as small as -1 μm or more and 1 μm or less, and the optical laminates No film lifting occurred visually during the entire manufacturing and post-heat treatment process, and the change in yellow index (ΔYI) before and after the 430 ° C post-heat treatment process was 7.3 or less, which was significantly lower than that of the comparative example, confirming good transparency retention and deterioration prevention ability. could

Claims (20)

base layer;
an inorganic vapor deposition layer formed on the base layer;
a first polyimide resin layer formed on the inorganic deposition layer;
a first inorganic material layer formed on the first polyimide resin layer;
a second polyimide resin layer formed on the first inorganic material layer; and
A second inorganic material layer formed on the second polyimide resin layer; including, an optical laminate.
According to claim 1,
An optical laminate having a yellowness change of 60 or less before and after the 430 ° C post-heat treatment process according to the following equation:
[mathematical expression]
Yellowness change before and after 430 ° C post-heat treatment (ΔYI) = (Yellowness of optical laminate after 430 ° C post-heat treatment (YI ₁ )) - (Yellowness of optical laminate before 430 ° C post-heat treatment (YI _{0 )} )).
According to claim 1,
The inorganic deposition layer formed on the glass substrate includes at least one selected from the group consisting of silicon-based materials and indium tin oxide.
According to claim 3,
Wherein the silicon-based material includes at least one selected from the group consisting of amorphous silicon, silicon oxide, and silicon nitride.
According to claim 1,
The maximum tensile strength of the first polyimide resin layer and the second polyimide resin layer is 140 MPa or more, the optical laminate.
According to claim 1,
The yellow index of the first polyimide resin layer and the second polyimide resin layer is 20 or less, the optical laminate.
According to claim 1,
The optical laminate, wherein the first polyimide resin layer and the second polyimide resin layer have transmittances of 85% or more at a wavelength of 550 nm.
According to claim 1,
The optical laminate, characterized in that the thickness of the first polyimide resin layer is greater than the thickness of the second polyimide resin layer.
According to claim 8,
Based on the thickness of the first polyimide resin layer of 1 μm, the thickness ratio of the second polyimide resin layer is 0.3 μm to 0.7 μm, the optical laminate.
According to claim 1,
Wherein the first polyimide resin layer and the second polyimide resin layer include a polyimide resin including a repeating unit derived from a diamine in which an electron withdrawing functional group is substituted, an optical laminate.
According to claim 1,
The first polyimide resin layer and the second polyimide resin layer include a polyimide resin including a repeating unit represented by Formula 1 below, an optical laminate:
[Formula 1]

In Formula 1,
X ₁ is an aromatic tetravalent functional group,
Y ₁ is an aromatic divalent functional group in which at least one electron withdrawing functional group is substituted.
According to claim 11,
The aromatic divalent functional group in which at least one electron withdrawing functional group of Y ₁ is substituted includes a divalent functional group represented by Formula 2 below, an optical laminate:
[Formula 2]

In Formula 2,
Q ₁ and Q ₂ are the same as or different from each other, and each independently represents an electron withdrawing functional group;
n and m are the same as or different from each other, and are each independently an integer of 1 or more and 4 or less.
According to claim 11,
A substrate for a display device or a flexible display device, wherein the first polyimide resin layer and the second polyimide resin layer further include a polyimide resin including a repeating unit represented by Formula 5 below:
[Formula 5]

In Formula 5,
X ₂ is an aromatic tetravalent functional group,
Y ₂ is an unsubstituted aromatic divalent functional group
According to claim 1,
The optical laminate, characterized in that the thickness of the first inorganic material layer is greater than the thickness of the second inorganic material layer.
According to claim 14,
Based on the thickness of the first inorganic material layer of 1 ㎛, the thickness ratio of the second inorganic material layer is 0.3 ㎛ to 0.7 ㎛, the optical laminate.
According to claim 1,
The optical laminate, wherein the first polyimide resin layer has a half-life of saturated charging voltage of 500 seconds or more.
According to claim 1,
An optical laminate having a change in yellowness of 10 or less before and after the heat treatment process at 430 ° C according to the following equation:
[mathematical expression]
Yellowness change before and after 430 ° C post-heat treatment (ΔYI) = (Yellowness of the polyimide resin layer in the optical laminate after 430 ° C post-heat treatment (YI ₁ )) - (Optical laminate before 430 ° C post-heat treatment) Yellowness of the polyimide resin layer within the polyimide resin layer (YI ₀ )).
According to claim 1,
Included in the optical laminate, the substrate layer; and an inorganic vapor deposition layer; the first heating step is performed from 50 °C to 430 °C at a heating rate of 5 °C/min, and then the cooling step is performed to 80 °C at a cooling rate of 4 °C/min. After that, the vertical direction thermal expansion level (dimension change) when the second heating process is performed at a temperature raising rate of 5 ° C / min to 480 ° C is -2 μm or more and 2 μm or less, the optical laminate.
A substrate for a display device comprising the optical laminate of claim 1 .
An optical device comprising the optical stack of claim 1 .