WO2020138687A1 - Polyamic acid composition for manufacturing display substrate and method for manufacturing display substrate by using same - Google Patents

Abstract

The present invention provides a polyamic acid composition having an adhesive strength of 0.05-0.1 N/cm with amorphous or crystalline silicon in a cured state on an amorphous or crystalline silicon substrate.

Description

Polyamic acid composition for manufacturing display substrate and method for manufacturing substrate for display using the same

Mutual citations with related applications

This application claims the benefit of priority based on Korean Patent Application No. 10-2018-0168515 filed on December 24, 2018, and all contents disclosed in the literature of the Korean patent application are incorporated as part of this specification.

Technology field

The present invention relates to a polyamic acid composition for manufacturing a display substrate and a method for manufacturing the display substrate using the same.

2. Description of the Related Art Display devices are rapidly evolving around flat panel displays (FPDs), which are easy to have a large area and can be thin and lightweight. The flat panel display includes a liquid crystal display (LCD), an organic light emitting display (OLED), or an electrophoretic device.

Recently, to further expand the application and use of such a flat panel display, a flexible display using a flexible substrate has been developed. Such displays are mainly applied to mobile devices such as smart phones and tablet PCs, and their application fields are expanding.

The display substrate constituting the flexible display may be manufactured by a process of forming a thin film transistor (TFTs on Plastic) device structure on a flexible substrate. However, since the above process is performed at a high temperature of 300° C. or higher or 400° C. or higher, among organic polymer materials, a polyimide-based material having the highest level of heat resistance and mechanical properties and flexible properties is preferably used as a flexible substrate.

Typically, the display substrate is (i) a polyamic acid solution, which is a precursor of polyimide, is applied and cured on a sacrificial layer made of amorphous or crystalline silicon to form a polyimide resin that is a flexible substrate, and (ii) thereafter a polyimide resin. The process of forming the thin film transistor device structure on the flexible substrate is performed, and (iii) when the process is completed, it can be manufactured by peeling the sacrificial layer from the flexible substrate using a laser having a predetermined wavelength. .

Although various process parameters may act in combination in the manufacture of a display substrate having a desired quality, one particularly important is that a flexible substrate, a polyimide resin, is adhered to an appropriate level to the sacrificial layer.

In the process of forming the thin film transistor device structure on the polyimide resin, the appropriate level of the above is maintained firmly in the adhesion state and shape of the polyimide resin and the sacrificial layer. When removing the sacrificial layer after this process, the sacrificial layer is removed from the polyimide resin. It means the level at which the layer can be easily peeled off.

If the adhesion of the polyimide resin to the sacrificial layer is poor, serious damage may occur in which the polyimide resin or the sacrificial layer is dropped in the process of forming a thin film transistor on the polyimide resin.

On the contrary, when the adhesive strength exceeds a certain level, the polyimide resin and a portion of the sacrificial layer are kept in the process of peeling the sacrificial layer with a laser, or ash derived from the sacrificial layer is applied to the polyimide resin. It may be glued. Due to this, the polyimide resin may be damaged during the peeling process, and the quality of the display substrate obtained by peeling may deteriorate. In addition, when the energy of the laser is amplified in order to completely peel the sacrificial layer maintaining the strong adhesion state, the structure of the polyimide resin or the thin film transistor device may be damaged or destroyed.

Therefore, there is a need for a novel polyimide-based material capable of solving the above-described technical problems.

An object of the present invention is to provide a novel polyamic acid composition capable of solving all of the conventional problems recognized above.

According to one aspect of the invention, the polyamic acid composition is cured on an amorphous or crystalline silicon substrate, that is, when converted to a polyimide resin, the adhesion to the amorphous or crystalline silicon may be 0.05 to 0.1 N/cm.

The adhesive force is maintained in a solid state of adhesion between the polyimide resin and the sacrificial layer, amorphous or crystalline silicon, in the process of forming a thin film transistor device structure on the polyimide resin derived from the polyamic acid composition, and sacrifice after this process. When removing the layer, the sacrificial layer can be easily peeled from the polyimide resin, which is particularly preferable.

By this aspect, the above-mentioned problems can be solved, and the present invention provides specific embodiments for its implementation.

In one embodiment, the present invention,

An aromatic dianhydride-based monomer and a polyamic acid polymer in which an aromatic diamine-based monomer is polymerized,

The aromatic dianhydride-based monomer includes a third component having a benzophenone structure,

The content of the third component having the benzophenone structure relative to the total number of moles of the aromatic dianhydride monomer is greater than 1 mol% and less than 7 mol%,

The polyamic acid composition, while cured on an amorphous or crystalline silicon substrate, provides a polyamic acid composition having an adhesion to the amorphous or crystalline silicon of 0.05 to 0.1 N/cm. The adhesive force may be the adhesive force measured while being attached to an amorphous or crystalline silicon substrate such that the width of the cured polyamic acid composition is 1 cm according to ASTM D 3359, and peeling at a peeling rate of 20 mm/min and a peeling angle of 180°. have.

In one embodiment, the present invention is a method of manufacturing a display substrate using a polyamic acid composition,

Hereinafter, embodiments of the present invention will be described in more detail in the order of “polyamic acid composition” and “method for manufacturing display substrate” according to the present invention.

Prior to this, the terms or words used in the present specification and claims should not be construed as being limited to ordinary or lexical meanings, and the inventor appropriately explains the concept of terms to explain his or her invention in the best way. Based on the principle that it can be defined, it should be interpreted as meanings and concepts consistent with the technical spirit of the present invention.

Therefore, the configuration of the embodiments described herein is only one of the most preferred embodiments of the present invention and does not represent all of the technical spirit of the present invention, and various equivalents and modifications that can replace them at the time of this application It should be understood that examples may exist.

In this specification, a singular expression includes a plural expression unless the context clearly indicates otherwise. In this specification, the terms "include", "have" or "have" are intended to indicate the presence of implemented features, numbers, steps, elements, or combinations thereof, one or more other features or It should be understood that the existence or addition possibilities of numbers, steps, elements, or combinations thereof are not excluded in advance.

As used herein, "dianhydride (dianhydride)" is intended to include its precursors or derivatives, which may not technically be dianhydrides, but will nevertheless react with diamines to form polyamic acids. And this polyamic acid can be converted back to polyimide.

“Diamine” as used herein is intended to include precursors or derivatives thereof, which may not technically be diamines, but will nevertheless react with dianhydrides to form polyamic acids, which are polyamic The acid can be converted back to polyimide.

Where an amount, concentration, or other value or parameter herein is given as an enumeration of a range, a preferred range, or a preferred upper and lower limits, any upper limit of any pair of any pair, regardless of whether the ranges are disclosed separately or It should be understood to specifically disclose all ranges that can be formed with preferred values and any lower range limits or desirable values. When a range of numerical values is referred to herein, unless stated otherwise, eg, unless there is a limiting term such as greater than, less than, the range is intended to include the endpoint and all integers and fractions within the range. It is intended that the scope of the invention not be limited to the specific values recited when defining a range.

Polyamic acid composition

The polyamic acid composition according to the present invention,

An aromatic dianhydride-based monomer and a polyamic acid polymer in which an aromatic diamine-based monomer is polymerized,

The aromatic dianhydride-based monomer includes a component having a benzophenone structure,

The content of the component having the benzophenone structure relative to the total number of moles of the aromatic dianhydride monomer is greater than 1 mol% and less than 7 mol%,

The polyamic acid composition, while cured on an amorphous or crystalline silicon substrate, may have an adhesive strength with the amorphous or crystalline silicon of 0.05 to 0.1 N/cm.

Specifically, the polyamic acid composition of the present invention includes an organic solvent; And

It may include a polyamic acid prepared by polymerization of an aromatic dianhydride-based monomer and an aromatic diamine-based monomer.

The aromatic dianhydride-based monomer may include a first component having a biphenyl structure, a second component having one benzene ring, and a third component having a benzophenone structure.

The aromatic diamine-based monomer may include a diamine component having one benzene ring in an amount of more than 50 mol% based on the total number of moles thereof.

Compared to the total number of moles of the aromatic dianhydride monomer, the content of the first component may be 50 mol% to 70 mol%.

Compared to the total number of moles of the aromatic dianhydride monomer, the content of the second component may be 20 mol% to 40 mol%.

Compared to the total number of moles of the aromatic dianhydride-based monomer, the content of the third component may be greater than 1 mol% and less than 7 mol%.

The polyamic acid composition, in a state cured on an amorphous or crystalline silicon substrate, may have an adhesive strength with the amorphous or crystalline silicon of 0.05 to 0.1 N/cm.

The polyamic acid composition may also be cured by heat treatment to form a polyimide resin. The polyamic acid composition may be heat-treated at 20°C to 550°C or 20°C to 500°C to produce a polyimide resin, and such polyimide resin may have excellent physical properties as follows.

-Thermal expansion coefficient below 8 ppm/℃

-Glass transition temperature above 490 ℃

-Pyrolysis temperature above 555 ℃

-Tensile strength over 350 MPa

-Elongation over 20%

-Transmittance over 60%

In this regard, in the case of the polyamic acid composition of the present invention and the polyimide resin prepared thereby, which can satisfy all of the above properties, it can be preferably used as a material for a display substrate.

The polyimide resin capable of expressing all of these properties and the polyamic acid composition realizing the same are novel polyimide-based materials that have not been known so far, and the configuration thereof will be described in more detail below through non-limiting examples.

<Adhesive force>

In general, the amorphous or crystalline silicon substrate may be used for the manufacture of a display substrate, but is not limited to, in particular, it may be used as a sacrificial layer that is adhered to and removed from the flexible substrate during manufacture of the display substrate. At this time, the polyamic acid composition of the present invention can be cured on the amorphous or crystalline silicon substrate to form a polyimide resin, and the polyimide resin can be preferably used as a flexible substrate.

An amorphous or crystalline silicon substrate as the sacrificial layer exists in a state of being attached to a polyimide resin in a process of forming a thin film transistor (TFT) device structure, and after this process, when an amorphous or crystalline silicon substrate is irradiated with laser, it is amorphous or crystalline The adhesive state of the silicon substrate and the polyimide resin may be released and peeled from each other.

However, it should be noted that, if the adhesive force is slightly outside the range described in the present invention, the thin film transistor element formed on the polyimide resin or the polyimide resin may be significantly damaged.

For example, if the adhesive force is slightly exceeded, a non-preferred aspect in which at least a portion of the amorphous or crystalline silicon substrate remains bonded to the polyimide resin despite treatment of the amorphous or crystalline silicon substrate with a laser Can lead to In this aspect, a portion of the polyimide resin whose adhesion is maintained can be broken by an amorphous or crystalline silicon substrate.

In addition, ash derived from an amorphous or crystalline silicon substrate may be adhered to the polyimide resin.

In another aspect, it may be considered to induce peeling of an amorphous or crystalline silicon substrate by using a laser having a higher energy, but in this case, the polyimide resin having a thickness of nanometers to micrometers and a thin film transistor device structure may be used. By affecting the laser of the energy, it is possible to cause their damage, for example, decomposition, deformation, and fracture of the resin and/or transistor element. In addition, high-energy lasers can generate relatively more ash originating from an amorphous or crystalline silicon substrate, which can act as a foreign body, for example, deteriorating the quality of a transistor device.

When the adhesive strength is satisfied, the adhesion state of the polyimide resin and the amorphous or crystalline silicon substrate at a high temperature of about 300° C. or higher or about 400° C. or higher can be well maintained.

This is a major reason that makes it difficult to use polyimide resin as a flexible substrate, because the process of forming a thin film transistor element structure on a polyimide resin is performed at a high temperature of about 300°C or higher. Under a relatively low adhesive force compared to the scope of the present invention, at least a part of the polyimide resin may be peeled off to cause an excited state, or the peeled part may curl to form a curl, in which case the process cannot be performed. Do.

In summary, it is important that the adhesion between the polyimide resin and the amorphous or crystalline silicon substrate is extremely limited and falls within the most preferred range, and the present invention provides such a preferred range as described above. In addition, the polyamic acid composition of the present invention can express the adhesive force in the above range to the amorphous or crystalline silicon substrate in a cured state.

Moreover, the polyamic acid composition of the present invention, in a cured state on an amorphous or crystalline silicon substrate, the adhesive force measured after laser irradiation may be 0.01 N/cm or less. The adhesive strength after the laser irradiation may be a level that the adhesion state with the amorphous or crystalline silicon substrate at a very small level cannot be substantially maintained, and thus, for example, the polyamic acid composition after the process of forming a thin film transistor device structure. The resulting polyimide resin can be easily peeled from the amorphous or crystalline silicon substrate, and its shape can be maintained intact.

The present invention provides a method of curing a polyamic acid composition to form a polyimide resin, and testing adhesion in this state.

The test method,

A polyimide resin in a state where a polyamic acid composition is coated on an amorphous or crystalline silicon substrate having a width of 1 cm*10 cm and heat-treated to form a thin film of polyimide resin of about 10 μm to 20 μm or 13 μm to 17 μm. A tape having a width of 1 cm is attached to the end of the product, and the required force is measured while peeling the polyimide resin from the substrate using the tape.

As a method of measuring the adhesive force after laser treatment, the following method can be used:

In a state where a polyamic acid composition is coated on an amorphous or crystalline silicon substrate having a width of 1 cm*10 cm and heat treated to form a polyimide resin thin film having a thickness of about 10 μm to 20 μm or 13 μm to 17 μm. Alternatively, after irradiating a laser having a wavelength of 308 nm to a crystalline silicon substrate, a tape having a width of 1 cm is attached to the end portion of the polyimide resin, and the required force is measured while peeling the polyimide resin from the substrate using the tape. .

The reason why the adhesive strength of the cured polyamic acid composition can satisfy the limited and most preferable range described in the present invention may be a main reason for the use of a third component having a benzophenone structure.

Specifically, in the polyamic acid composition of the present invention, the polymer chain of the polyamic acid may include a benzophenone structure by a third component having a benzophenone structure, and the benzophenone structure is a polyimide in which the polyamic acid polymer chain is converted. It can also be retained in the polymer chain. The benzophenone structure may improve adhesion through interaction with a polar functional group such as a hydroxy group present on the surface of an amorphous or crystalline silicon substrate, and the structure of the third component and its content satisfy the scope of the present invention Finally, the adhesive force with an object to be adhered, such as an amorphous or crystalline silicon substrate, can be mainly expressed in a desired level.

The adhesive strength of a conventional polyimide resin belongs to an extremely low side, and for example, it may have a lower adhesive strength of less than 0.05 N/cm for an amorphous or crystalline silicon substrate. This may be attributed to the fact that the polyimide resin includes a Weak Boundary Layer (WBL) at a contact interface with an amorphous or crystalline silicon substrate. The surface vulnerable layer has various forms, but one of them may be in an excited form, at least part of the polyimide resin does not support the amorphous or crystalline silicon substrate at the contact interface.

The excited form is generated by, for example, moisture and/or organic solvents that volatilize when the attractive force acting at the interface between the polyimide resin and the amorphous or crystalline silicon substrate is weak or is converted from the polyamic acid composition to the polyimide resin. Can be.

The third component may improve the adhesion level of the polyimide resin through interaction with a polar functional group in which the benzophenone structure is present on the amorphous or crystalline silicon substrate.

In addition, the benzophenone structure of the third component may be advantageous in that volatilization of moisture and/or an organic solvent is easily achieved at an initial point in time when the polyamic acid composition is converted to a polyimide resin. The resin can advantageously act to suppress the excitation from an amorphous or crystalline silicon substrate.

As a result, the third component advantageously acts to minimize the formation of this surface fragile layer in the polyimide resin, which may be related to the polyimide resin having a desired level of adhesion.

However, it is not preferable to use the third component in a predetermined amount or more in consideration of only the above-mentioned advantages, because the adhesion of the polyimide resin to the amorphous or crystalline silicon substrate is significantly increased, so that it can easily exceed 0.1 N/cm. .

In addition, the use of the third component can excessively increase the glass transition temperature and the coefficient of thermal expansion of the polyimide resin, which is desirable for the production of display substrates, for example, produced by chemical/physical interactions with inorganic materials. Do not

Therefore, the content of the third component should be particularly carefully selected in a range in which the adhesive strength of the polyimide resin may fall within the range of 0.05 to 0.1 N/cm, and the glass transition temperature and the coefficient of thermal expansion are not realized in a non-desirable manner. do.

In one example, the content of the third component, compared to the total number of moles of the aromatic dianhydride monomer, may be greater than 1 mol% to less than 7 mol%, and may be 2 mol% to 5 mol%, 3 mol To 5 mol%.

In the present invention, the third component having a benzophenone structure may be 3,3',4,4'-benzophenone tetracarboxylic dianhydride (BTDA).

<Other physical properties>

The third component having a benzophenone structure may be a pair of benzene rings curved based on a carbonyl group, and thus may be a relatively flexible monomer in terms of molecular structure, and the flexible monomer is a thermal expansion coefficient of a polyimide resin derived from a polyamic acid composition. It can help increase.

However, the thermal expansion coefficient of most inorganic materials, including amorphous or crystalline silicon, is less than 9 ppm/°C or 8 ppm/°C or less, so that the polyimide resin capable of being adhered to the inorganic material is too large. Having may be quite undesirable in terms of dimensional stability.

The coefficient of thermal expansion can generally be reduced when using rigid monomers in terms of molecular structure. The rigidity in terms of molecular structure may mean a molecular structure in which the main chain between diamine groups or carboxyl groups is composed of one benzene ring, and thus the main chain is difficult to bend.

The second component may be a component having one benzene ring, pyromellitic dianhydride (PMDA), and the polyimide resin derived from the polyamic acid composition of the present invention may advantageously function to have a low coefficient of thermal expansion. have.

However, when only the pyromellitic dianhydride having such a rigid structure is used in combination with the third component, the thermal expansion coefficient of the polyimide film may be lowered to less than 6 ppm/°C or 1 ppm/°C or less, and polya The polyimide resin converted from the mixed acid composition may exhibit brittle brittle characteristics and may have a relatively low elongation.

Therefore, in the present invention, it should be noted that as the aromatic dianhydride-based monomer, the first component is further included together with the second component and the third component.

The first component having a biphenyl structure is not a rigid molecular structure compared to the second component, but it can be considered to have a more flexible molecular structure and a more rigid molecular structure for the third component, and consequently the molecular structure for rigidity or flexibility. In aspect, the first component can be a material between the second component and the third component.

The polyamic acid composition of the present invention, due to the first component, may have an elongation of 20% or more, and the elongation may preferably act, for example, in a process of forming a thin film transistor device structure.

In addition, as the first component, the second component, and the third component are combined, the polyimide resin derived from the polyamic acid composition of the present invention is 8 ppm/°C or less, 7.7 ppm/°C or less, or 6 ppm/°C to 7 ppm/ It may have an appropriate coefficient of thermal expansion of ℃, may have an excellent glass transition temperature of 490 ℃ or more or a glass transition temperature of 500 ℃ to 550 ℃ or more tensile strength of 350 MPa or more or 370 MPa or more.

In order to realize the above, it is particularly important that the first component and the second component are combined in a desirable amount, and thus the present invention provides the preferred contents of the first component and the second component.

In one example, the content of the first component relative to the total number of moles of the aromatic dianhydride monomer is 50 mol% to 70 mol%, 55 mol% to 65 mol%, 57 mol% to 62 mol% or 58 mol % To 60 mol%.

Compared to the total number of moles of the aromatic dianhydride-based monomer, the content of the second component is 20 mol% to 40 mol%, 30 mol% to 40 mol%, 32 mol% to 38 mol%, or 35 mol% to 38 mol%. Can.

If the content of the first component satisfies the above range, the polyimide resin may exhibit an appropriate level of elongation, thermal expansion coefficient, and glass transition temperature.

The aromatic dianhydride-based monomer may further include some other dianhydride components in addition to the first to third components described above.

These dianhydride components include, but are not limited to, 2,3,3',4'-biphenyltetracarboxylic dianhydride (a-BPDA), oxydiphthalic dianhydride (ODPA), diphenylsulfone- 3,4,3',4'-tetracarboxylic dianhydride (DSDA), bis(3,4-dicarboxyphenyl)sulfide dianhydride, 2,2-bis(3,4-dicarboxyphenyl) -1,1,1,3,3,3-hexafluoropropane dianhydride, 2,3,3',4'- benzophenonetetracarboxylic dianhydride, bis(3,4-dicarboxyphenyl )Methane dianhydride, 2,2-bis(3,4-dicarboxyphenyl)propane dianhydride, p-phenylenebis (trimeric monoester acid anhydride), p-biphenylenebis (tri Mellitic monoester acid anhydride), m-terphenyl-3,4,3',4'-tetracarboxylic dianhydride, p-terphenyl-3,4,3',4'-tetracar Bisilic dianhydride, 1,3-bis(3,4-dicarboxyphenoxy)benzene dianhydride, 1,4-bis(3,4-dicarboxyphenoxy)benzene dianhydride, 1,4- Bis(3,4-dicarboxyphenoxy)biphenyl dianhydride, 2,2-bis[(3,4-dicarboxy phenoxy)phenyl]propane dianhydride (BPADA), 2,3,6,7 -Naphthalenetetracarboxylic acid dianhydride, 1,4,5,8-naphthalenetetracarboxylic dianhydride, 4,4'-(2,2-hexafluoroisopropylidene)diphthalic acid dianhydride, etc. Can be lifted.

Meanwhile, the diamine component having one benzene ring may have a molecular structure in which the main chain between diamine groups is composed of one benzene ring, so that the main chain is difficult to bend.

As described above, the thermal expansion coefficient of most inorganic materials, including amorphous or crystalline silicon, is relatively small, and it is preferable that the polyimide resin applied thereto has a thermal expansion coefficient similar to that of inorganic materials.

The diamine component having one benzene ring may be preferable in that it can lower the coefficient of thermal expansion, and in another aspect, it may advantageously act to improve the glass transition temperature of the polyimide resin. In addition, an aspect in which the diamine component can compensate for an increase in the coefficient of thermal expansion due to the second component used in a relatively low content can also be recognized as a desirable factor.

The diamine component having one benzene ring is 1,4-diaminobenzene (PPD), 1,3-diaminobenzene (MPD), 2,4-diaminotoluene, 2,6-diaminotoluene and 3, A component comprising at least one member selected from 5-diaminobenzoic acid may be selected as the diamine component.

Among them, 1,4-diaminobenzene, which is advantageous for improving tensile strength and can be advantageously combined with the pyromellitic dianhydride to induce a thermal expansion coefficient to a desired level, is a diamine component having one benzene ring. It may be desirable.

The aromatic diamine-based monomer may include a diamine component having one benzene ring in an amount greater than 50 mol%, 60 mol% or more, or 70 mol% to 100 mol% based on the total number of moles thereof.

When the content of the diamine component satisfies the above range, the polyimide resin may exhibit an appropriate level of elongation, thermal expansion coefficient, and glass transition temperature.

The aromatic diamine-based monomer may further include some other dianhydride components in addition to the diamine components described above.

Such diamine components include, but are not limited to, diaminodiphenyl ethers such as 4,4'-diaminodiphenyl ether (or oxidianiline, ODA), 3,4'-diaminodiphenyl ether, and 4,4'. -Diaminodiphenylmethane (or methylenedianiline, MDA), 3,3'-dimethyl-4,4'-diaminobiphenyl, 2,2'-dimethyl-4,4'-diaminobiphenyl, 2 ,2'-bis(trifluoromethyl)-4,4'-diaminobiphenyl, 3,3'-dimethyl-4,4'-diaminodiphenylmethane, 3,3'-dicarboxy-4, 4'-diaminodiphenylmethane, 3,3',5,5'-tetramethyl-4,4'-diaminodiphenylmethane, bis(4-aminophenyl)sulfide, 4,4'-diaminobenz Anilide, 3,3'-dimethylbenzidine (or o-tolidine), 2,2'-dimethylbenzidine (or m-tolidine), 3,3'-dimethoxybenzidine, 2,2'-dimethoxybenzidine , 3,3'-diaminodiphenyl ether, 3,4'-diaminodiphenyl ether, 4,4'-diaminodiphenyl ether, 3,3'-diaminodiphenylsulfide, 3,4'- Diaminodiphenylsulfide, 4,4'-diaminodiphenylsulfide, 3,3'-diaminodiphenylsulfone, 3,4'-diaminodiphenylsulfone, 4,4'-diaminodiphenylsulfone, 3,3'-diaminobenzophenone, 4,4'-diaminobenzophenone, 3,3'-diamino-4,4'-dichlorobenzophenone, 3,3'-diamino-4,4'- Dimethoxybenzophenone, 3,3'-diaminodiphenylmethane, 3,4'-diaminodiphenylmethane, 4,4'-diaminodiphenylmethane, 2,2-bis(3-aminophenyl)propane , 2,2-bis(4-aminophenyl)propane, 2,2-bis(3-aminophenyl)-1,1,1,3,3,3-hexafluoropropane, 2,2-bis(4 -Aminophenyl)-1,1,1,3,3,3-hexafluoropropane, 3,3'-diaminodiphenylsulfoxide, 3,4'-diaminodiphenylsulfoxide, 4,4' -Diaminodiphenyl sulfoxide 1,3-bis(3-aminophenyl)benzene, 1,3-bis(4-aminophenyl)benzene, 1,4-bis(3-aminophenyl)benzene, 1,4- Bis(4-amino phenyl)benzene, 1,3-bis(4-aminophenoxy)benzene (or TPE-R), 1,4-bis(3-aminophenoxy)benzene (or TPE-Q) 1, 3-bis(3-aminophenoxy) -4-trifluoromethylbenzene, 3,3'-diamino-4-(4-phenyl)phenoxybenzophenone, 3,3'-diamino-4,4'-di(4-phenylphenoxy) Benzophenone, 1,3-bis(3-aminophenylsulfide)benzene, 1,3-bis(4-aminophenylsulfide)benzene, 1,4-bis(4-aminophenylsulfide)benzene, 1,3- Bis(3-aminophenylsulfone)benzene, 1,3-bis(4-aminophenylsulfone)benzene, 1,4-bis(4-aminophenylsulfone)benzene, 1,3-bis[2-(4-amino Phenyl)isopropyl]benzene, 1,4-bis[2-(3-aminophenyl)isopropyl]benzene, 1,4-bis[2-(4-aminophenyl)isopropyl]benzene, 3,3'- Bis(3-aminophenoxy)biphenyl, 3,3'-bis(4-aminophenoxy)biphenyl, 4,4'-bis(3-aminophenoxy)biphenyl, 4,4'-bis( 4-aminophenoxy)biphenyl, bis[3-(3-aminophenoxy)phenyl]ether, bis[3-(4-aminophenoxy)phenyl]ether, bis[4-(3-aminophenoxy) Phenyl] ether, bis [4-(4-aminophenoxy)phenyl] ether, bis [3-(3-aminophenoxy)phenyl] ketone, bis [3-(4-aminophenoxy)phenyl] ketone, bis [4-(3-aminophenoxy)phenyl]ketone, bis[4-(4-aminophenoxy)phenyl]ketone, bis[3-(3-aminophenoxy)phenyl]sulfide, bis[3-(4 -Aminophenoxy)phenyl]sulfide, bis[4-(3-aminophenoxy)phenyl]sulfide, bis[4-(4-aminophenoxy)phenyl]sulfide, bis[3-(3-aminophenoxy) Phenyl] sulfone, bis [3-(4-aminophenoxy)phenyl] sulfone, bis [4-(3-aminophenoxy)phenyl] sulfone, bis [4-(4-aminophenoxy)phenyl] sulfone, bis [3-(3-aminophenoxy)phenyl]methane, bis[3-(4-aminophenoxy)phenyl]methane, bis[4-(3-aminophenoxy)phenyl]methane, bis[4-(4 -Aminophenoxy)phenyl]methane, 2,2-bis[3-(3-aminophenoxy)phenyl]propane, 2,2-bis[3-(4-aminophenoxy)phenyl]propane, 2,2 -Bis[4-(3-aminophenoxy)phenyl]propane, 2,2-bis[4-(4-aminophenoxy)phenyl]propane (BAPP), 2,2-bis[3-(3-amino Phenoxy)phenyl]-1,1,1,3,3,3-hexafluoropropane, 2,2-bis[3-(4-aminophenoxy)phenyl]-1,1,1,3,3,3-hexafluoropropane, 2,2-bis[4-(3-aminophenoxy) Phenyl]-1,1,1,3,3,3-hexafluoropropane and 2,2-bis[4-(4-aminophenoxy)phenyl]-1,1,1,3,3,3- Hexafluoropropane is exemplified.

As described above, the polyamic acid composition according to the present invention has a desirable adhesion to implement a display substrate due to the third component, and in addition, as the first component and the second component are combined, various characteristics required for the polyimide It may be a reasonable level.

<additive>

The polyamic acid composition according to the present invention may further include at least one of a silane-based coupling agent and a silicone-based surfactant.

The silane-based coupling agent is a part of which is bonded to the imide group of the polyimide resin in which the amic acid group or the amic acid group of the polyamic acid composition is converted, and the other part is an inorganic material, for example, a silicon-based material, for example, amorphous or It can be combined with oxygen or silicon present in a crystalline silicon substrate.

By this action, the silane coupling agent can increase the adhesion of the polyimide resin derived from curing of the polyamic acid composition within the range of 0.05 to 0.1 N/cm.

However, the excessive use of the silane-based coupling agent may cause deterioration in the physical properties of the polyimide resin derived from the polyamic acid composition, and thus it may be preferable to use an extremely limited content.

As an example for this, the silane coupling agent may be included in the polyamic acid composition in an amount of 0.01 to 0.05% by weight, 0.01 to 0.03% by weight, or 0.018 to 0.022% by weight based on the weight of the polyamic acid solid content of the polyamic acid composition.

The silane-based coupling agent that can be preferably included in the polyamic acid composition of the present invention is not limited to, 3-aminopropyl trimethoxysilane ((3-Aminopropyl)trimethoxysilane, APTMS), aminopropyl triethoxysilane (Aminopropyltriethoxysilane), 3-(2-aminoethylamino)propyl-dimethoxymethylsilane, 3-glycidoxypropyldimethoxymethylsilane and 2-(3,4 -Epoxycyclohexyl) trimethoxysilane (2-(3,4-epoxycyclohexyl) trimethoxysilane) may include one or more selected from the group consisting of, particularly preferably, including an amine group, polyamic acid composition of 3-Aminopropyl trimethoxysilane, aminopropyl triethoxysilane and 3-(2-aminoethylamino)propyl-dimethoxymethylsilane which are easy to be bonded to the imide group of the polyimide resin in which the amic acid group or the amic acid group is converted. It may include one or more selected from the group consisting of, most preferably 3-aminopropyl trimethoxysilane which may be advantageous in preventing deterioration of the physical properties of the polyimide resin derived from the polyamic acid composition.

The silicone-based surfactant, for example, when the polyamic acid composition is applied to an inorganic substrate or the like, may preferably act to make the polyamic acid composition having fluidity spread well on the substrate to form a uniform thickness.

However, when the surfactant is included in an excessive amount, at least a part of the polyamic acid composition may be agglomerated to make film formation difficult, and may cause deterioration in physical properties of the polyimide resin derived from curing the polyamic acid composition. On the contrary, surfactants contained in small amounts are not preferable because they do not help with the advantages related to the previous film formation.

The preferred surfactant content may be 0.001 to 0.02% by weight, and 0.005 to 0.015% by weight or 0.008 to 0.012% by weight based on the polyamic acid solids weight of the polyamic acid composition.

The type of the surfactant is not particularly limited, but a silicone-based surfactant may be preferable. The silicone surfactant can be easily obtained commercially, for example, BYK's'BYK-378' can be used as a silicone surfactant. However, the above examples are intended to help the practice of the invention, and the surfactant that can be used in the present invention is not limited to the above examples.

The polyamic acid composition may also include at least one selected from acetic anhydride (AA), propionic acid anhydride, and lactic acid anhydride, quinoline, isoquinoline, β-picoline (BP), and pyridine. A curing accelerator may be further included.

Such a curing accelerator may assist in obtaining a desired polyimide resin by promoting the cyclization reaction through dehydration of the polyamic acid when forming a polyamic acid composition and converting it into a polyimide resin.

The curing accelerator may be included in an amount of 0.05 to 20 mol with respect to 1 mol of the amic acid group in the polyamic acid.

When the curing accelerator satisfies the above range, dehydration and/or cyclization can be promoted to be cast in the form of a thin film, and an excellent strength polyimide resin can be produced.

The polyamic acid composition may further include a filler for the purpose of improving various properties of the polyimide resin such as sliding property, thermal conductivity, and loop hardness of the polyimide resin derived from the polyamic acid composition.

The filler is not particularly limited, and preferred examples include silica, titanium oxide, alumina, silicon nitride, boron nitride, calcium hydrogen phosphate, calcium phosphate, and mica.

The average particle diameter of the filler is not particularly limited, and can be determined according to the characteristics of the polyimide resin to be modified and the type of filler to be added. In one example, the average particle diameter of the filler may be 0.05 μm to 100 μm, 0.1 μm to 75 μm, 0.1 μm to 50 μm, or 0.1 μm to 25 μm.

If the average particle diameter satisfies this range, the modification effect is excellent, and the surface properties of the polyimide resin and its mechanical properties can be induced.

In addition, the addition amount of the filler is not particularly limited, and can be determined by the characteristics of the polyimide resin to be modified, the particle size of the filler, and the like.

In one example, the amount of the filler added is 0.01 to 100 parts by weight, 0.01 to 90 parts by weight, or 0.02 to 80 parts by weight based on 100 parts by weight of the polyamic acid composition.

If the amount of the filler added satisfies this range, the modification effect by the filler is excellent, and the mechanical properties of the polyimide resin can be improved. The method for adding the filler is not particularly limited, and any known method can be used.

<Method for preparing polyamic acid composition>

The method for producing the polyamic acid constituting the polyamic acid composition is, for example,

(1) a method in which the total amount of the diamine-based monomer is put in an organic solvent, and then the dianhydride-based monomer is added to be substantially equimolar with the diamine-based monomer and polymerized;

(2) a method in which the total amount of the dianhydride-based monomer is placed in an organic solvent, and thereafter the diamine-based monomer is added to be substantially equimolar with the dianhydride-based monomer and polymerized;

(3) After adding some components of the diamine-based monomer in an organic solvent, after mixing some components of the dianhydride-based monomer with respect to the reaction component in a ratio of about 95 mol% to 105 mol%, the remaining diamine-based monomer components A method of polymerization by adding and subsequently adding the remaining dianhydride-based monomer components such that the diamine-based monomer and the dianhydride-based monomer become substantially equimolar;

(4) After adding the dianhydride-based monomer in an organic solvent, after mixing some components of the diamine compound in a ratio of 95 mol% to 105 mol with respect to the reaction component, another dianhydride-based monomer component is added and continuously A method in which the remaining diamine-based monomer component is added to polymerize the diamine-based monomer and the dianhydride-based monomer to become substantially equimolar; And

(5) Some diamine-based monomer components and some dianhydride-based monomer components are reacted so as to be in excess in one of the organic solvents to form a first polymerization product, and some diamine-based monomer components and some dianhydrides in another organic solvent. As a method of reacting a ride-based monomer component so that either one is in excess, forming a second polymer, mixing the first and second polymers and completing the polymerization, wherein a diamine-based monomer is used to form the first polymer. When the component is excessive, the second polymer is an excess of the dianhydride-based monomer component, and when the first polymer is the excess of the dianhydride-based monomer component, the second polymerization product is an excess of the diamine-based monomer component. And a method in which 1, the second polymerized materials are mixed and the total diamine-based monomer component and the dianhydride-based monomer component used in these reactions are substantially equimolar.

However, the above method is an example for helping the implementation of the present invention, and the scope of the present invention is not limited to them, and it is of course possible to use any known method.

The organic solvent is not particularly limited as long as it is a solvent in which the polyamic acid can be dissolved, but as an example, the organic solvent may be an aprotic polar solvent.

As a non-limiting example of the aprotic polar solvent, amide solvents such as N,N'-dimethylformamide (DMF), N,N'-dimethylacetamide (DMAc), p-chlorophenol, o-chloro And phenol-based solvents such as phenol, N-methyl-pyrrolidone (NMP), gamma brotirolactone (GBL), and digrime, and these may be used alone or in combination of two or more.

In some cases, the solubility of the polyamic acid may be controlled by using auxiliary solvents such as toluene, tetrahydrofuran, acetone, methyl ethyl ketone, methanol, ethanol, and water.

In one example, organic solvents that can be particularly preferably used for preparing the polyamic acid composition of the present invention may be N-methyl-pyrrolidone, N,N'-dimethylformamide and N,N'-dimethylacetamide. .

The polyamic acid composition thus prepared may have a viscosity measured at 23°C of 3,000 cP to 7,000 cP, 3,500 cP to 6,500 cP, or 4,000 cP to 5,500 cP. The viscosity may be a viscosity measured with a Brookfield viscometer on the spindle RV-7 under conditions of a temperature of 23° C. and a rotation speed of 0.5 rpm. In the present application, the polyamic acid composition may have a solid content of 5 to 30%, 10 to 25%, or 12 to 20%. When the viscosity of the polyamic acid composition satisfies the above range, the fluidity of the polyamic acid composition can be improved to smooth the coating process and improve the adhesion of the polyimide resin.

Method for manufacturing display substrate using polyamic acid composition

The present invention provides a method of manufacturing a display substrate using the polyamic acid composition of the preceding embodiment.

Specifically, the method,

And coating the polyamic acid composition on an amorphous or crystalline silicon substrate.

In addition, the manufacturing method of the present application comprises the steps of first heat-treating the polyamic acid composition at 20°C to 40°C;

A second heat treatment of the polyamic acid composition at 40°C to 200°C; And

The polyamic acid composition may include a third heat treatment at 200°C to 500°C.

Through the first heat treatment, the second heat treatment, and the third heat treatment step, the polyamic acid composition produces a polyimide resin containing an imide group in which the amic acid group of polyamic acid is closed and dehydrated, and an organic solvent is volatilized and cured. , When the third heat treatment is completed, the polyimide resin may be cured and adhered on the amorphous or crystalline silicon substrate.

In one specific example, in the step of applying the polyamic acid composition on the amorphous or crystalline silicon substrate, the thickness of the polyimide resin produced after the polyamic acid composition is cured is 0.5 μm to 20 μm, 2 μm to 18 The polyamic acid composition may be applied so as to be µm or 2 to 5 µm.

In one specific example, the first heat treatment, the second heat treatment, and the third heat treatment step, respectively, independently, 3 °C / min to 7 °C / min, two or more variable heating rate selected from the range, or in the above range It can be carried out at a single constant heating rate selected.

Manufacturing method according to the invention,

Forming a thin film transistor (TFT) on the polyimide resin, and

The method may further include removing the amorphous or crystalline silicon substrate from the polyimide resin by irradiating the amorphous or crystalline silicon substrate with a laser for a predetermined time.

It may be 0.01 N/cm or less between the polyimide resin and the amorphous or crystalline silicon substrate measured after the laser irradiation.

The adhesive strength after the laser irradiation may be a level that the adhesion state with the amorphous or crystalline silicon substrate at a very small level cannot be substantially maintained, and thus, for example, the polyamic acid composition after the process of forming a thin film transistor device structure. The resulting polyimide resin can be easily peeled from the amorphous or crystalline silicon substrate, and its shape can be maintained intact.

In the step of removing the amorphous or crystalline silicon substrate, the laser may be performed by a laser lift off (LLO) method.

The energy density (E/D) of the laser may be 180 mJ/cm ² or less, and preferably 150 mJ/cm ² or less.

As described above, the polyamic acid composition according to the present invention can express the most desirable adhesion to an amorphous or crystalline silicon substrate by a third component having a benzophenone structure.

The polyamic acid composition according to the present invention is also a polyimide resin in which various properties required for the production of a display substrate are incorporated at an appropriate level by a combination of a diamine-based monomer and a diamine-based monomer containing a specific component. You can implement

Hereinafter, the operation and effects of the invention will be described in more detail through specific examples of the invention. However, these examples are only presented as examples of the invention, and the scope of the invention is not thereby determined.

<Example 1>

In an NMP-filled reactor at 40° C., PPD as the aromatic dianhydride-based monomer as BPDA (first component), PMDA (second component), BTDA (third component) and aromatic diamine-based monomer is shown in the molar ratio shown in Table 1 below. It was added and stirred for about 30 minutes to polymerize the polyamic acid.

Here, the following materials were added, and the aging process was performed for about 2 hours to prepare a final polyamic acid composition. At this time, the viscosity of the polyamic acid composition was about 5,100 cP.

-Silane coupling agent: 0.02% by weight of 3-aminopropyl trimethoxysilane (based on the weight of solid polyamic acid)

-Silicone surfactant: 0.01% by weight of BYK's'BYK-378' (based on the weight of solid polyamic acid)

-Additive: 10% by weight of isoquinoline (based on the weight of solid polyamic acid)

<Example 2>

The viscosity was about 5,000 cP in the same manner as in Example 1, except that the molar ratios of BPDA (first component), PMDA (second component), and BTDA (third component) were changed and added to the molar ratios shown in Table 1 below. A polyamic acid composition was prepared.

<Example 3>

The viscosity was about 5,100 cP in the same manner as in Example 1, except that the molar ratios of BPDA (first component), PMDA (second component), and BTDA (third component) were changed and added to the molar ratios shown in Table 1 below. A polyamic acid composition was prepared.

<Example 4>

The viscosity was about 4,800 cP in the same manner as in Example 1, except that the molar ratios of BPDA (first component), PMDA (second component), and BTDA (third component) were changed and added to the molar ratios shown in Table 1 below. A polyamic acid composition was prepared.

<Comparative Example 1>

BTDA (third component) was excluded as a component of the aromatic dianhydride-based monomer, except that the molar ratio of BPDA (first component) and PMDA (second component) was changed to and added to the molar ratio shown in Table 1 below. A polyamic acid composition having a viscosity of about 4,800 cP was prepared in the same manner as in Example 1.

<Comparative Example 2>

BTDA (third component) was excluded as a component of the aromatic dianhydride-based monomer, except that the molar ratio of BPDA (first component) and PMDA (second component) was changed to and added to the molar ratio shown in Table 1 below. A polyamic acid composition having a viscosity of about 5,300 cP was prepared in the same manner as in Example 1.

<Comparative Example 3>

BTDA (third component) was excluded as a component of the aromatic dianhydride-based monomer, except that the molar ratio of BPDA (first component) and PMDA (second component) was changed to and added to the molar ratio shown in Table 1 below. A polyamic acid composition having a viscosity of about 4,750 cP was prepared in the same manner as in Example 1.

<Comparative Example 4>

BTDA (third component) was excluded as a component of the aromatic dianhydride-based monomer, except that the molar ratio of BPDA (first component) and PMDA (second component) was changed to and added to the molar ratio shown in Table 1 below. A polyamic acid composition having a viscosity of about 4,950 cP was prepared in the same manner as in Example 1.

<Comparative Example 5>

The viscosity was about 5,100 cP in the same manner as in Example 1, except that the molar ratios of BPDA (first component), PMDA (second component), and BTDA (third component) were changed and added to the molar ratios shown in Table 1 below. A polyamic acid composition was prepared.

<Comparative Example 6>

A polyamic acid of about 5,100 cP in the same manner as in Example 1, except that the molar ratios of BPDA (first component), PMDA (second component), and BTDA (third component) were changed and added to the molar ratios shown in Table 1 below. The composition was prepared.

	Furtherance				Mole ratio
	Dianhydride monomer			Diamine monomer	Dianhydride monomer			Diamine monomer
	1st ingredient	Second ingredient	Third component		1st ingredient	Second ingredient	Third component
Example 1	BPDA	PMDA	BTDA	PPD	60	38	2	100
Example 2	BPDA	PMDA	BTDA	PPD	60	35	5	100
Example 3	BPDA	PMDA	BTDA	PPD	55	40	5	100
Example 4	BPDA	PMDA	BTDA	PPD	65	32	3	100
Comparative Example 1	BPDA	PMDA	-	PPD	60	40	-	100
Comparative Example 2	BPDA	PMDA	-	PPD	70	30	-	100
Comparative Example 3	BPDA	PMDA	-	PPD	80	20	-	100
Comparative Example 4	BPDA	PMDA	-	PPD	50	50	-	100
Comparative Example 5	BPDA	PMDA	BTDA	PPD	60	39	One	100
Comparative Example 6	BPDA	PMDA	BTDA	PPD	60	33	7	100

<Experimental Example 1: Adhesion test of polyimide resin>

The polyamic acid compositions prepared in Examples 1 to 4 and Comparative Examples 1 to 6 were cast to 30 μm on an amorphous silicon substrate having a width of 1 cm*10 cm and dried in a temperature range of 20° C. to 460° C., resulting in an average thickness. A laminate in which a polyimide resin in the form of a thin film having a thickness of about 15 to 17 μm and an amorphous silicon substrate was adhered was prepared.

The first adhesive strength (before laser treatment), curl test, and second adhesive strength (after laser treatment) of the polyimide resin were evaluated for the laminate thus prepared.

-First adhesive force: A tape having a width of 1 cm is attached to the end of the polyimide resin, and the required force is measured while peeling the polyimide resin from the substrate using the tape.

-Curl test: The prepared laminate was heat-treated at a temperature of about 400° C. for about 1 hour, and then, it was confirmed whether curls were generated at the corners of the polyimide resin on the amorphous silicon substrate.

-Second adhesive force: After irradiating an amorphous silicon substrate with a laser having a wavelength of 308 nm at 150 mJ/cm ² , a tape having a width of 1 cm is attached to the end of the polyimide resin and the polyimide resin is used from the substrate using this tape. While peeling, the force required for this is measured.

-The adhesive force was measured according to ASTM D 3359, peeling at a peeling rate of 20 mm/min and a peeling angle of 180°.

	First adhesive force (N/cm)	Whether curl occurs (O, X)	Second adhesive force (N/cm)
Example 1	0.07	X	0.01 or less
Example 2	0.08	X	0.01 or less
Example 3	0.07	X	0.01 or less
Example 4	0.07	X	0.01 or less
Comparative Example 1	0.03	O	0.01 or less
Comparative Example 2	0.03	O	0.01 or less
Comparative Example 3	0.03	O	0.01 or less
Comparative Example 4	0.03	O	0.01 or less
Comparative Example 5	0.03	O	0.01 or less
Comparative Example 6	0.12	X	0.05

<Experimental Example 2: Property test of polyimide resin>

The polyamic acid compositions prepared in Examples 1 to 5 and Comparative Examples 1 to 6 were applied to a stainless steel support in the form of a thin film, and then heat treated at a temperature range of 20°C to 350°C, and then peeled from the support to obtain an average thickness, respectively. A polyimide resin in the form of a film of about 15 to 17 μm was prepared.

The physical properties of the polyimide resin thus prepared were tested in the following manner, and the results are shown in Table 3 below.

(1) Coefficient of thermal expansion (CTE)

The coefficient of thermal expansion was measured in the range of 100 to 350°C using TMA.

(2) Glass transition temperature (T _g )

The glass transition temperature was obtained by using TMA to obtain the loss modulus and storage modulus of each polyimide resin, and the inflection point was measured as the glass transition temperature in their tangent graph.

(3) Pyrolysis temperature (T _d )

A thermogravimetric analyzer (TG-DTA2000) was used to measure the temperature when the initial weight of the polyimide resin decreased by 1% while heating at a heating rate of 10°C/min in nitrogen.

(4) Tensile strength

Tensile strength was measured by the method presented in KS6518.

(5) Elongation

Elongation was measured by the method set forth in ASTM D1708.

(6) transmittance

By using the ColorQuesetXE model of HunterLab, the transmittance of 550 nm wavelength was measured by the method presented in ASTM D1003 in the visible light region.

	CTE (ppm/℃)	T g (℃)	T d (℃)	Tensile strength (MPa)	Elongation (%)	Transmittance (%)
Example 1	6.2	507	567	385	23.8	60.8
Example 2	6.4	509	563	388	23.4	61.0
Example 3	6.7	506	561	382	22.7	60.7
Example 4	7.7	495	559	374	24.8	61.3
Comparative Example 1	6.3	508	566	382	23.8	60.7
Comparative Example 2	11.8	481	569	347	27.9	62.1
Comparative Example 3	14.1	435	565	324	34.8	65.7
Comparative Example 4	5.8	521	556	398	15.2	57.1
Comparative Example 5	6.1	508	563	378	22.8	60.4
Comparative Example 6	9.5	489	561	382	17.5	61.8

From the results of Experimental Example 1, the Examples expressed an appropriate level of adhesion to the amorphous silicon substrate, that is, a first adhesion belonging to 0.05 to 0.1 N/cm. The advantage of the first adhesion belonging to the above range is whether curling occurs or not Can be confirmed indirectly through. According to Table 2, in the embodiment, curling did not occur at all even when heat treatment was performed at a high temperature of 400° C. for a predetermined time. If the adhesive strength is low, the adhesive state between the polyimide resin and the amorphous silicon substrate is released at a high temperature of 400° C., and curls may be generated where the ends of the polyimide resin are dried inward. In fact, most of the comparative examples exhibited a lower first adhesive force than the examples, and curls were all generated.

These results suggest that an adhesive force of at least 0.05 N/cm is required for the TFT process performed at a high temperature, and it can be seen that the embodiment according to the present invention expresses a desirable adhesive force for the TFT process. In another aspect, the embodiment showed an extremely slight adhesion (second adhesion) after treatment with a laser for removal of the amorphous silicon substrate, from which the amorphous silicon substrate from the polyimide resin once the first adhesion was met It can be expected that this can peel off well.

On the other hand, Comparative Examples 1 to 5 can be confirmed that the first adhesive force is out of the range of 0.05 to 0.1 N/cm. Due to the low first adhesive force, the comparative examples can generate curl at high temperature, and it can be expected that it is unsuitable for manufacturing a display substrate requiring a high temperature process.

Comparative Example 6 is a case where the first adhesive strength is excessive, and in particular, it can be confirmed that the second adhesive strength after laser treatment is also very high, which is unlikely to be difficult to separate the amorphous silicon substrate from the polyimide resin after laser irradiation unlike the example. Suggests

The results of Experimental Example 2 show that the polyimide resin implemented according to the present invention satisfies all the various characteristics required for the manufacture of the display substrate, and when linking with the results of Experimental Example 1, all of the Examples, Together they express the desired level of adhesion.

On the contrary, it can be seen that the comparative example has poor adhesion, and at least one property is not satisfied, so that it is difficult to be used as a display substrate.

Therefore, it can be seen from the results of Table 3 that the monomer combination and the combination ratio of the present invention are effective for the implementation of the polyamic acid composition.

Although described above with reference to embodiments of the present invention, those of ordinary skill in the art to which the present invention pertains will be able to make various applications and modifications within the scope of the present invention based on the above.

Claims (20)

1. An aromatic dianhydride-based monomer and a polyamic acid polymer in which an aromatic diamine-based monomer is polymerized,

   The aromatic dianhydride-based monomer includes a third component having a benzophenone structure,

   The content of the component having the benzophenone structure relative to the total number of moles of the aromatic dianhydride monomer is greater than 1 mol% and less than 7 mol%,

   The polyamic acid composition, in a state cured on an amorphous or crystalline silicon substrate, the polyamic acid composition having an adhesive strength with the amorphous or crystalline silicon of 0.05 to 0.1 N/cm.
2. According to claim 1,

   The aromatic dianhydride-based monomer further comprises a first component having a biphenyl structure and a second component having one benzene ring.
3. According to claim 2,

   The polyamic acid composition in which the content of the first component is 50 mol% to 70 mol%, and the content of the second component is 20 mol% to 40 mol%, relative to the total number of moles of the aromatic dianhydride monomer.
4. According to claim 2,

   The first component is 3,3',4,4'-biphenyltetracarboxylic dianhydride (BPDA) and 2,3,3',4'-biphenyltetracarboxylic dianhydride (a- BPDA) at least one polyamic acid composition selected from the group consisting of.
5. According to claim 2,

   The second component is a pyromellitic dianhydride (PMDA) polyamic acid composition.
6. According to claim 2,

   The third component is a 3,3',4,4'-benzophenone tetracarboxylic dianhydride (BTDA) polyamic acid composition.
7. According to claim 1,

   The aromatic diamine-based monomer is a polyamic acid composition comprising a diamine component having one benzene ring in an amount greater than 50 mol% based on the total number of moles thereof.
8. The method of claim 7,

   The diamine component having one benzene ring is 1,4-diaminobenzene (PPD), 1,3-diaminobenzene (MPD), 2,4-diaminotoluene, 2,6-diaminotoluene and 3, At least one polyamic acid composition selected from the group consisting of 5-diaminobenzoic acid.
9. The method of claim 7,

   The diamine component having one benzene ring is 1,4-diaminobenzene.
10. According to claim 1,

    A polyamic acid composition having an adhesive strength of 0.01 N/cm or less measured after laser irradiation in a cured state on an amorphous or crystalline silicon substrate.
11. According to claim 1,

    A polyamic acid composition further comprising at least one of a silane coupling agent and a silicone surfactant.
12. The method of claim 11,

    The silane coupling agent,

    0.01 to 0.05% by weight based on the weight of the polyamic acid solids of the polyamic acid composition;

    3-aminopropyltrimethoxysilane (APTMS), aminopropyltriethoxysilane, 3-(2-aminoethylamino)propyl-dimethoxymethylsilane (3-(2- aminoethylamino)propyl-dimethoxymethylsilane, 3-glycidoxypropyldimethoxymethylsilane and 2-(3,4-epoxycyclohexyl) trimethoxysilane (2-(3,4-epoxycyclohexyl)trimethoxysilane) A polyamic acid composition comprising one or more selected from the group consisting of.
13. The method of claim 11,

    The silicone-based surfactant is a polyamic acid composition contained in an amount of 0.001 to 0.02% by weight relative to the polyamic acid solids weight of the polyamic acid composition.
14. According to claim 1,

    A polyamic acid composition having a viscosity of 3,000 to 7,000 cP measured at 23° C. of the polyamic acid composition.
15. According to claim 1,

    The polyimide resin prepared by heat-treating the polyamic acid composition at 20°C to 400°C,

    Glass transition temperature is 490 ℃ or higher,

    Pyrolysis temperature is 555 ℃ or higher,

    A polyamic acid composition having a thermal expansion coefficient of 8 ppm/℃ or less.
16. The method of claim 15,

    The polyimide resin is a polyamic acid composition having a tensile strength of 350 MPa or more, an elongation of 20% or more, and a transmittance of 60% or more.
17. A method of manufacturing a display substrate comprising the step of applying the polyamic acid composition according to claim 1 on an amorphous or crystalline silicon substrate.
18. The method of claim 17, further comprising: subjecting the polyamic acid composition to a first heat treatment at 20°C to 40°C;

    A second heat treatment of the polyamic acid composition at 40°C to 200°C; And

    And a third heat treatment of the polyamic acid composition at 200°C to 500°C,

    Through the first heat treatment, the second heat treatment, and the third heat treatment step, the polyamic acid composition produces a polyimide resin containing an imide group in which the amic acid group of polyamic acid is closed and dehydrated, and an organic solvent is volatilized and cured. ,

    When the third heat treatment is completed, a method of manufacturing a display substrate to which the polyimide resin is cured and adhered on the amorphous or crystalline silicon substrate.
19. The method of claim 18,

    Each of the first heat treatment, the second heat treatment, and the third heat treatment step is independently, two or more variable heating rates selected from the range of 3°C/min to 7°C/min, or one constant selected from the range. Manufacturing method performed at a heating rate.
20. The method of claim 18,

    Forming a thin film transistor (TFT) on the polyimide resin, and

    And irradiating the amorphous or crystalline silicon substrate with a laser for a predetermined time to remove the amorphous or crystalline silicon substrate from the polyimide resin,

    A manufacturing method in which the adhesive force between the polyimide resin and the amorphous or crystalline silicon substrate measured after the laser irradiation is 0.01 N/cm or less.