JP2021534275A - Polyimide film and flexible devices using it - Google Patents

Abstract

The present invention is produced from a diamine containing DDS and an amine-terminated methylphenylsiloxane oligomer and a polyamic acid produced by using two or more kinds of tetracarboxylic acid dianhydrides as polymerization components, and the distribution rate of pores in the polyimide film is 1. By adjusting / adjusting to% or less and adjusting the average size of the phase separation domain to 10 nm or less, flexible that mechanical defects such as cracks do not occur in the LTPS thin film layer even in a high temperature process such as the LTPS process. Devices can be provided.

Description

This application has priority based on the Republic of Korea Patent Application Nos. 10-2018-9096802 and 10-2018-9096803 dated August 20, 2018 and the Republic of Korea Patent Application No. 10-2019-010019 dated August 16, 2019. Any content claimed for benefit and disclosed in the literature of the Republic of Korea patent application is included as part of this specification.

The present invention relates to a polyimide film having excellent heat resistance in a high temperature process and a flexible device using the polyimide film.

Recently, in the display field, weight reduction and miniaturization of products have been emphasized. In the case of a glass substrate, it is heavy and often cracks, and there is a limit that continuous processes are difficult. Research is being actively pursued for application to telephones, notebook computers, PDAs, and the like.

In particular, polyimide (PI) resin has the advantages that it is easy to synthesize, can form a thin film, and does not require a cross-linking group for curing. Recently, the weight and precision of electronic products have been improved. Due to this phenomenon, it is often applied as an integrated material to semiconductor materials such as LCDs and PDPs. Further, research on using PI resin for a flexible display substrate (flexible plastic display board) having a light and flexible property is being actively promoted.

A polyimide (PI) film is produced by forming a polyimide resin into a film. Generally, a polyimide film is obtained by solution polymerization of aromatic dianhydride and aromatic diamine or aromatic diisocyanate to obtain a polyamic acid derivative solution. After manufacturing, it is manufactured by coating it on a silicon wafer, glass, etc. and curing (imidizing) it by heat treatment.

Flexible devices with a high temperature process are required to have heat resistance at a high temperature, but in particular, in the case of an OLED (organic light emitting diode) device using an LTPS (low temperature temperature polysilicon) process, the process temperature is close to 500 ° C. .. However, at such a temperature, even a polyimide having excellent heat resistance is likely to undergo thermal decomposition due to hydrolysis. Therefore, in order to manufacture a flexible device, it is necessary to develop a polyimide film capable of exhibiting excellent heat resistance.

An object to be solved by the present invention is to provide a polyimide film having improved heat resistance at high temperatures.

Another problem to be solved by the present invention is to provide a flexible device using the polyimide film and a manufacturing process thereof.

In order to solve the problem of the present invention, a diamine component containing a diamine having the structure of the following chemical formula 1 and an amine-terminated methylphenylsiloxane oligomer; and a dianhydride component containing two or more kinds of tetracarboxylic acid dianhydrides; Provided is a polyimide film containing a polymerization of a polymerization component containing and an imidization product, wherein the distribution rate of pores in the film is 1% or less.

。 [Chemical formula 1]

..

Further, the present invention comprises a diamine component containing a diamine having the structure of the chemical formula 1 and an amine-terminated methylphenylsiloxane oligomer; and a dianhydride component containing two or more kinds of tetracarboxylic acid dianhydrides; A polyimide film containing a polymerization and imidization product, wherein a plurality of domains derived from the amine-terminated methylphenylsiloxane oligomer are dispersed in the polyimide matrix derived from the diamine of the chemical formula 1, and the average of the plurality of domains is dispersed. Provided is a polyimide film having a size of 10 nm or less.

According to one embodiment, the amine-terminated methylphenylsiloxane oligomer has the structure of the following chemical formula 2.

[Chemical formula 2]

In the above formula, p and q are mole fractions, where p is 70 to 90 and q is 10 to 30 when p + q = 100.

According to one example, the dianhydride component comprises biphenyltetracarboxylic dianhydride (BPDA) and pyromellitic dianhydride (PMDA).

According to one embodiment, the dianhydride component contains BPDA and PMDA in a mol ratio of 6: 4 to 8: 2.

According to one embodiment, the polymerization component may contain 5 to 30% by weight of the amine-terminated methylphenylsiloxane oligomer based on the total weight of the total polymerization component.

According to one embodiment, the polymerization component may contain 1 to 10 mol% of the amine-terminated methylphenylsiloxane oligomer based on the total diamine component.

According to one embodiment, the modulus of the polyimide film is 2.2 GPa or less, and the draw ratio is 20% or more.

According to one embodiment, the glass transition temperature (Tg) of the polyimide film is 230 ° C. or higher.

The present invention also provides a flexible device including the polyimide film.

The present invention also reacts a diamine component containing the diamine of the chemical formula 1 and an amine-terminated methylphenylsiloxane oligomer with a dianhydride component containing two or more types of tetracarboxylic acid dianhydride to form a polyimide precursor composition. The stage of producing a product; the stage of applying the produced polyimide precursor composition onto a carrier substrate; the stage of forming a polyimide film by heating and imidizing the polyimide precursor composition; on the polyimide film. Provided is a step of manufacturing a flexible device including a step of forming an element; and a step of peeling the polyimide film on which the element is formed from the carrier substrate.

According to one embodiment, the manufacturing process may include one or more steps selected from the group consisting of LTPS (low temperature polysilicon) thin film manufacturing steps, ITO thin film manufacturing steps or Oxide thin film manufacturing steps.

In the present invention, a diamine containing diaminodiphenyl sulfone (DDS) and an amine-terminated methylphenylsiloxane oligomer and two or more kinds of tetracarboxylic acid dianhydrides are used as polymerization components, and the pore distribution rate in the polyimide film is 1%. By adjusting / adjusting to the following and adjusting the size of the phase separation domain to 10 nm or less, the inorganic film formed in a high temperature process such as a LTPS step, an ITO step or an Oxide step is mechanically cracked. It is possible to provide a flexible device that does not generate defects.

It is a figure explaining the method of measuring the distribution ratio of the pore in the polyimide film from the FIB-SEM (Focused Ion Beam Scanning Electron Microscopes) image of the polyimide film. It is a drawing explaining the method of measuring the distribution ratio of a phase separation domain from a FIB-SEM image of a polyimide film. It is a figure which showed the FIB-SEM image of the polyimide film by the comparative example 1. FIG. It is a figure which compared the FIB-SEM image with the same DPS-DMS content with respect to the polyimide film by the comparative example and the Example. It is a figure which compared the FIB-SEM image with the same DPS-DMS content with respect to the polyimide film by the comparative example and the Example. It is a figure which compared the FIB-SEM image with the same DPS-DMS content with respect to the polyimide film by the comparative example and the Example. 11 is a FIB-SEM image of the polyimide film according to Example 11, Example 13, Example 14, and Example 15. It is a photograph showing the state after _{SiO 2} vapor deposition and heat treatment on the polyimide film according to Comparative Example 3, Comparative Example 4 and Example 1.

Since the present invention can be subjected to various transformations and have various examples, specific examples will be illustrated in the drawings and described in detail with detailed description. However, this is not intended to limit the invention to any particular embodiment, but must be understood to include any transformations, equivalents or alternatives contained within the ideas and technical scope of the invention. It doesn't become. In explaining the present invention, if it is determined that a specific description of the related publicly known technique may obscure the gist of the present invention, the detailed description thereof will be omitted.

As used herein, any compound or organic group is substituted or unsubstituted, unless otherwise specified. Here, "substitution" means that at least one hydrogen contained in the compound or organic group is a halogen atom, an alkyl group having 1 to 10 carbon atoms, an alkyl halide group, a cycloalkyl group having 3 to 30 carbon atoms, and carbon. A group consisting of an aryl group having 6 to 30 groups, a hydroxy group, an alkoxy group having 1 to 10 carbon atoms, a carboxylic acid group, an aldehyde group, an epoxy group, a cyano group, a nitro group, an amino group, a sulfonic acid group, and derivatives thereof. Means replaced with a substituent selected from.

According to the uniformity of the present invention, a diamine component containing the compound of the following chemical formula 1 and a double-ended amine-modified dimethylsiloxane (DMS) -diphenylsiloxane (DPS) oligomer; and two or more tetracarboxylic acid dianhydrides. Provided is a polyimide film containing a polymerization and curing product of a polymerization component containing an anhydride component; the polyimide film having a pore distribution ratio in the film of 1% or less.

。 [Chemical formula 1]

..

According to another aspect of the present invention, a diamine component containing the compound of the chemical formula 1 and a double-ended amine-modified dimethylsiloxane (DMS) -diphenylsiloxane (DPS) oligomer; and two or more tetracarboxylic acid dianhydrides. A polyimide film containing a polymerization and curing product of a polymerization component containing a dianhydride component; in which a plurality of domains derived from the amine-terminated methylphenylsiloxane oligomer are dispersed in a polyimide matrix derived from the diamine of the chemical formula 1. A polyimide film having an average size of 10 nm or less of the plurality of domains is provided.

The compounds represented by the chemical formula 1 are, for example, 4,4- (diaminodiphenyl) sulfone (hereinafter, 4,4-DDS), 3,4- (diaminodiphenyl) sulfone (3,4-DDS), and 3,3. -One or more selected from the group consisting of (diaminodiphenyl) sulfone (3,3-DDS).

INDUSTRIAL APPLICABILITY The present invention significantly reduces the ratio of pores generated during the process of producing a polyimide film containing a siloxane oligomer structure by using DDS of chemical formula 1 together with an amine-terminated methylphenylsiloxane oligomer as a polymerization component in the production of polyamic acid. sell. The pores formed in the polyimide film are not desirable because they subsequently generate cracks in the inorganic film formed on the polyimide film.

In the process of manufacturing a polyimide film containing an amine-terminated methylphenylsiloxane oligomer structure, chain breakage and rearrangement of the siloxane oligomer structure occur during the high-temperature curing step, and pores are generated inside the polyimide film by such a process. There is a fear. At this time, in the polyimide having a structure having a high modulus, that is, the polyimide having a rigid structure, the mobility at a high temperature is not high, and the pores generated from the above process remain inside the film. , The ratio of pores in the film increases. On the other hand, the polyimide film according to the present invention has high fluidity at high temperature by using a diamine containing a flexible structure like DDS, and pores can escape to the outside in the process of forming the film. As a result, the proportion of pores present inside the film is significantly reduced.

At this time, the stomatal distribution rate is measured as follows.

After fixing the image of the polyimide film measured by FIB-SEM at 100,000 magnification to 100 mm x 80 mm, the area is subdivided into 2 mm x 2 mm, and pores are present based on the entire area (2000 areas in total). Measure by region ratio. FIG. 1 shows a method for measuring the stomatal distribution rate using a FIB-SEM image.

For example, when there are two regions (2ea) in which pores exist, the pore distribution ratio is as follows.

Pore distribution rate (%) = 2/2000x100 = 0.1%

Since a polyimide chain containing a siloxane structure such as an amine-terminated methylphenylsiloxane oligomer can exhibit polarity, phase separation occurs due to the difference in polarity from the polyimide chain that does not contain a siloxane structure, whereby the siloxane structure is formed. It is unevenly distributed in the polyimide matrix. In this case, the siloxane structure cannot improve the strength of the polyimide and the effect of improving the physical properties such as stress relief, and the haze increases due to the phase separation, and the transparency of the film decreases. In particular, when the diamine containing the siloxane oligomer structure has a high molecular weight, the polarity of the polyimide chain produced thereby is more clearly shown, and the phase separation phenomenon between the polyimide chains is more clearly shown. In order to avoid such a problem, when a low molecular weight siloxane oligomer is used, a large amount of siloxane oligomer must be added in order to obtain an effect such as stress relief, but in this case, it is low. Problems such as Tg generation at temperature occur, and the physical properties of the polyimide film deteriorate.

Thereby, in the present invention, by using the diamine of Chemical Formula 1 together with the amine-terminated methylphenylsiloxane oligomer, the siloxane oligomer structure is uniformly distributed in the polyimide matrix without phase separation.

According to the uniformity of the present invention, there is provided a polyimide film in which the average size of the phase-separated domain generated by the polyimide containing such a structure derived from amine-terminated methylphenylsiloxane is adjusted to 10 nm or less. At this time, the phase-separated domain means an amine-terminated methylphenylsiloxane domain distributed in the polyimide matrix. The size of such a phase-separated domain means the maximum diameter of the white circle surrounding the region in the FIB-SEM image of polyimide.

In the polyimide film according to the present invention, the average size of the phase-separated domain is 10 nm or less, and indicates, for example, a phase-separated domain having a very small size of 1 to 10 nm, that is, a domain derived from an amine-terminated methylphenylsiloxane. Since the size of such phase separation is 10 nm or less in the polyimide film, it is possible to have a continuous phase, whereby residual stress can be minimized while maintaining heat resistance and mechanical properties. .. When it does not have such a continuous phase, it has an effect of reducing residual stress, but heat resistance and mechanical properties are remarkably reduced, and it is difficult to use it in a process.

It is desirable that the portion (domain) containing the amine-terminated methylphenylsiloxane structure is linked in the polyimide matrix in a continuous phase. Here, the continuous phase means that nano-sized domains are uniformly distributed in the polyimide matrix. It means the shape of the shape.

Therefore, in the present invention, by using DDS of chemical formula 1 together with an amine-terminated methylphenylsiloxane oligomer as a polymerization component in the production of polyamic acid, phase separation by the amine-terminated methylphenylsiloxane appears, but the average size thereof is 10 nm. It becomes very small below and the phase separation domains can be evenly distributed in the polyimide matrix, reducing the problems manifested by phase separation. For example, a polyimide having more transparent properties can be obtained by reducing the occurrence of haze caused by phase separation. Further, since the amine-terminated methylphenylsiloxane structure exists in a continuous phase, the mechanical strength of the polyimide and the stress-relieving effect are improved. With such properties, the polyimide film according to the present invention can provide a flat polyimide film in which not only the optical properties but also the degree of bending of the substrate is reduced after the coating is cured.

The distribution ratio of the phase-separated domain contained in the polyimide film is about 25 to 60% in the polyimide film, preferably 50% or less or 40% or less.

At this time, as shown in FIG. 2, the distribution ratio of the phase-separated domain was determined by fixing the image of 100,000 magnification analyzed by FIB-SEM to 100 mm × 70 mm, subdividing the area into 2 mm × 2 mm, and whitening each of them. After dividing into a white) or black area, it is calculated by a method of calculating the ratio of the white area from the entire area.

For example, if the total area is 1750 and the white area is 650,

The phase separation domain distribution rate is calculated as% = (650/1750) x 100 = 32%.

In the polyimide film, when the phase separation distribution ratio measured as described above is 25% or less, the residual stress is high, warping of the substrate occurs during the TFT process, and when it is 60% or more, it is excessive. A decrease in Tg and a white turbidity (haze) phenomenon appear due to phase separation.

According to one embodiment, the amine-terminated methylphenylsiloxane oligomer has the structure of the following chemical formula 2.

[Chemical formula 2]

In the above formula, p and q are mole fractions, where p is 70 to 90 and q is 10 to 30 when p + q = 100.

According to one embodiment, the diamine of the chemical formula 2 is based on the total solid content of the polyimide copolymer, that is, the weight of the polyimide resin precursor or the total weight of the polymerization components (diamine component and acid dianhydride component). 5 to 30% by weight, preferably 10 to 25% by weight, and more preferably 10 to 20% by weight.

If a diamine containing the structure of the chemical formula 2 is added in an excessive amount, the mechanical properties such as the modulus of polyimide are deteriorated, and the strength of the film is reduced, so that the film is torn in the process. There is a risk of damage. Further, when the diamine having the structure of Chemical Formula 2 is excessively added, Tg derived from the polymer having the siloxane structure appears, and from this, Tg appears at a low process temperature of 350 ° C. or lower, and 350 ° C. or higher. During the process of depositing the inorganic film, the surface of the film may be wrinkled due to the flow phenomenon of the polymer, and the inorganic film may be cracked.

The molecular weight of the diamine compound having the structure of the chemical formula 2 is 4000 g / mol or more. According to one embodiment, the molecular weight is 5000 g / mol or less, or 4500 g / mol or less. Here, the molecular weight means a weight average molecular weight, and the calculation of the molecular weight can use a method of calculating the amine equivalent using NMR analysis or an acid-base appropriate method.

When the molecular weight of the siloxane oligomer containing the structure of the chemical formula 2 is less than 4000 g / mol, the heat resistance is lowered, for example, the glass transition temperature (Tg) of the produced polyimide is lowered, or the coefficient of thermal expansion is lowered. Increase excessively.

According to one example, the double-ended diamine-modified siloxane oligomer containing the structure of Chemical Formula 2 is contained in an amount of 1 to 20 mol%, preferably 1 mol% or more and 10 mol% or less or 5 mol% or less of the total diamine. ..

It is desirable that the polyimide film according to the present invention contains two or more kinds of tetracarboxylic dianhydrides as a polymerization component, and contains both BPDA and PMDA as tetracarboxylic dianhydrides. Further, it is desirable that BPDA and PMDA are contained in a mol ratio of 6: 4 to 8: 2 or 5: 5 to 7: 3.

During the polyamic acid polymerization for producing the polyimide film according to the present invention, a tetracarboxylic dianhydride other than BPDA and PMDA is further contained, and for example, a tetravalent organic selected from the structures of the following chemical formulas 3a to 3h. It may further contain a tetracarboxylic dianhydride containing a group.

[Chemical formula 3a]

[Chemical formula 3b]

[Chemical formula 3c]

[Chemical formula 3d]

[Chemical formula 3e]

[Chemical formula 3f]

[Chemical formula 3g]

[Chemical formula 3h]

In Formula 3h from Formula _{3a, R 24} from _{R 11} are each independently -F, -Cl, halogen atom selected from the group consisting of -Br, and -I, hydroxyl (-OH), an thiol group (- SH), nitro group (-NO ₂ ), cyano group, alkyl group with 1 to 10 carbon atoms, halogenoalkoxy with 1 to 4 carbon atoms, halogenoalkyl with 1 to 10 carbon atoms, aryl group with 6 to 20 carbon atoms Substituents to be selected, a1 is an integer of 0 to 2, a2 is an integer of 0 to 4, a3 is an integer of 0 to 8, and a4 and a5 are independently integers of 0 to 3. A7 and a8 are independently integers of 0 to 3, a10 and a12 are independently integers of 0 to 3, a11 is an integer of 0 to 4, and a15 and a16 are independent. The integers from 0 to 3 and a17 and a18 are independently integers from 0 to 4, and a6, a9, a13, a14, a19, and a20 are independently integers from 0 to 3. n is an integer of 1 to 3, and A ₁₁ to A ₁₆ are independently single-coupled, −O−, −CR'R''−, −C (= O) −, −C (=). It is selected from the group consisting of O) O-, -C (= O) NH- _{, -S-, -SO 2-} , a phenylene group, and a combination thereof, in which case R'and R'' Is independently selected from the group consisting of a hydrogen atom, an alkyl group having 1 to 10 carbon atoms, and a fluoroalkyl group having 1 to 10 carbon atoms.

^{Here, *} displayed in the chemical formula indicates a binding site.

During the polyamic acid polymerization for producing the polyimide film according to the present invention, the diamine component further contains a diamine other than the DDS of the chemical formula 1 and the amine-terminated methylphenylsiloxane of the chemical formula 2, and has a structure as shown in the following chemical formula 4, for example. It may further contain the diamine it has.

[Chemical formula 4]

In the chemical formula 4, R ₃₁ and R ₃₂ are each independently selected from the group consisting of -F, -Cl, -Br and -I, a halogen atom, a hydroxyl group (-OH), a thiol group (-SH), and the like. It is selected from a nitro group (-NO ₂ ), a cyano group, an alkyl group having 1 to 10 carbon atoms, a halogenoalkoxy having 1 to 4 carbon atoms, a halogenoalkyl group having 1 to 10 carbon atoms, and an aryl group having 6 to 20 carbon atoms. It is a substituent, preferably a substituent selected from a halogen atom, a halogenoalkyl group, an alkyl group, an aryl group and a cyano group. For example, the halogen atom is fluoro (-F), and the halogenoalkyl group is a fluoroalkyl group having 1 to 10 carbon atoms including a fluoro atom, which is a fluoromethyl group, a perfluoroethyl group, or a trifluoromethyl group. The alkyl group is selected from a methyl group, an ethyl group, a propyl group, an isopropyl group, a t-butyl group, a pentyl group, a hexyl group, and the like, and the aryl group is a phenyl group. It is selected from a group and a naphthalenyl group, and more preferably a fluoro-based substituent containing a fluoro atom such as a fluoro atom and a fluoroalkyl group.

At this time, the "fluoro-based substituent" means not only a "fluoroatomic substituent" but also a "fluoroatom-containing substituent".

Q is a single bond, -O-, -CR'R "-, -C (= O)-, -C (= O) O-, -C (= O) NH-, -S-,- It is selected from the group consisting of SO _2- , a phenylene group, and a combination thereof, in which the R'and R'' are independently hydrogen atoms and alkyl groups having 1 to 10 carbon atoms, respectively. And one selected from the group consisting of fluoroalkyl groups having 1 to 10 carbon atoms.

The precursor composition for producing the polyimide film according to the present invention further contains an adhesion enhancer, and the adhesion enhancer is 0.05 to 3 parts by weight, preferably 0, as compared with 100 parts by weight of the total solid content. Included in 05-2 parts by weight.

According to one embodiment, the adhesion enhancer comprises the structure of Chemical Formula 5 or Chemical Formula 6 below.

[Chemical formula 5]

[Chemical formula 6]

In the chemical formulas 5 and 6, Q ₁ is a tetravalent organic group having 1 to 30 carbon atoms or a tetravalent organic group represented by _Ra- L-R _{b , and Ra} and R _b are. It is a monovalent organic group selected from an aliphatic group having 4 to 10 carbon atoms, an aromatic group having 6 to 24 carbon atoms, and a cyclic aliphatic group having 3 to 24 carbon atoms, each of which is independently substituted or unsubstituted. Is a single bond, -O-, -CR'R "-, -C (= O)-, -C (= O) O-, -C (= O) NH-, -S-, -SO. _{It is selected from the group consisting of 2-} , a phenylene group, and a combination thereof, in which case R'and R'' are independently hydrogen atoms, an alkyl group having 1 to 10 carbon atoms, and carbon. It is selected from the group consisting of the number 1 to 10 fluoroalkyl groups, and more preferably L is selected from -SO _2- , -CO-, -O-, C (CF ₃ ) _2. in and, _{Q 2} is a divalent organic group represented by a divalent organic group or _R c _{-L-R d} C1-30, _{R c} and _{R d} are each independently It is a monovalent organic group selected from a substituted or unsubstituted aliphatic having 4 to 10 carbon atoms, an aromatic group having 6 to 24 carbon atoms, and a cyclic aliphatic group having 3 to 24 carbon atoms, and L is a single. Binding, -O-, -CR'R''-, -C (= O)-, -C (= O) O-, -C (= O) NH-, -S-, -SO _2- , phenylene It is selected from the group consisting of groups and combinations thereof, in which case R'and R'' are independently hydrogen atoms, alkyl groups having 1 to 10 carbon atoms, and 1 to 10 carbon atoms, respectively. R ₁ and R ₃ are independently alkyl groups having 1 to 5 carbon atoms, and R ₂ and R ₄ are independently hydrogen atoms. Alternatively, it is an alkyl group having 1 to 5 carbon atoms, more preferably an ethyl group, and a and b are independently integers of 1 to 3 respectively.

For example, the Q ₁ is, is a tetravalent organic group from the following chemical formula 5a is selected from Formula 5s, not limited thereto.

In the chemical formula 6, Y is a divalent organic group selected from the following chemical formulas 6a to 6t, but is not limited thereto.

The adhesive enhancer containing the structures of the chemical formulas 5 and 6 not only improves the adhesive force with the baseless layer, but also has low reactivity with the polyamic acid. When an alkoxysilane-based additive such as ICTEOS or APTEOS, which is a general adhesive strength improving additive, is added, the increase in viscosity caused by a side reaction between the polyamic acid and the additive is reduced, and the increase in viscosity at room temperature is reduced. Improves storage stability.

The highly heat-resistant polyimide used as a conventional flexible display substrate is made by applying an adhesive enhancer on the glass in order to improve the adhesiveness with the glass used as a carrier substrate or the glass substrate on which a baseless layer is vapor-deposited. However, such an existing adhesive enhancer has a limit of low economic efficiency in terms of the process because foreign matter is generated by the application of the adhesive enhancer or an additional coating process is required. Further, even when the adhesion enhancer is directly added to the polyimide resin precursor, there is a problem that the amino group is precipitated by forming a carboxylic acid of the polyamic acid and a salt, and the adhesiveness is deteriorated.

There is also a prior art in which an adhesion enhancer can be synthesized and directly added to the polyimide precursor to improve the adhesiveness, but since an acid anhydride having a relatively rigid structure is used, it is adhered after curing. There is a problem that the phase difference delay phenomenon appears in the part of the enhancer, resulting in an increase in the phase difference value in the thickness direction of the produced polyimide film. Further, when an adhesion enhancer containing a flexible structure such as ODPA (4,4'-oxydiphthalic anhydride) is used, the phase difference value does not increase due to the flexibility of the structure, but the Tg tends to decrease. There is.

According to the preferred embodiment, the adhesion enhancer has a fluorene skeleton, in which case the fluorene skeleton creates an intermolecular free volume while preserving the effect of the adhesion enhancer to the maximum, and the packing. It does not affect the packing density and can exhibit isotropic properties. In addition, it has excellent heat resistance due to its structural characteristics containing a large amount of aromatics. That is, even if an adhesion enhancer is mixed with the polyimide resin precursor and used, it does not precipitate and the generation of foreign matter can be minimized. It is possible to provide an isotropic polyimide film without affecting the phase difference in the thickness direction, which is the optical property of the obtained polyimide film.

According to one embodiment of the present invention, the dianhydride component and the diamine component are 1: 0.9 to 0.9: 1, 1: 0.98 to 0.98: 1, or 1: 0.99 to 0. It reacts at a ratio of .99: 1 mol, and preferably, in order to improve the reactivity and the processability, the dianhydride component reacts in an excessive amount as compared with the diamine component, or the diamine component is a dianhydride component. It reacts with an excessive amount compared to. According to the desired embodiment, it is desirable that the dianhydride component reacts in excess of the diamine (eg, dianhydride: diamine = 1: 0.995 to 0.999).

Examples of the organic solvent that can be used during the polyamic acid polymerization reaction include γ-butyrolactone, 1,3-dimethyl-2-imidazolidinone, methyl ethyl ketone, cyclohexanone, cyclopentanone, 4-hydroxy-4-methyl-2-pentanone and the like. Ketones; aromatic hydrocarbons such as toluene, xylene, tetramethylbenzene; ethylene glycol monoethyl ether, ethylene glycol monomethyl ether, ethylene glycol monobutyl ether, diethylene glycol monoethyl ether, diethylene glycol monomethyl ether, diethylene glycol monobutyl ether, propylene glycol. Glycol ethers (cellosolve) such as monomethyl ether, propylene glycol monoethyl ether, dipropylene glycol diethyl ether, triethylene glycol monoethyl ether; ethyl acetate, butyl acetate, ethylene glycol monoethyl ether acetate, ethylene glycol monobutyl ether acetate, diethylene glycol Monoethyl ether acetate, dipropylene glycol Monomethyl ether acetate, ethanol, propanol, ethylene glycol, propylene glycol, carbitol, dimethylpropionamide (DMPA), diethylpropionamide (DEPA), dimethylacetamide (DMAc), N. , N-diethylacetamide, dimethylformamide (DMF), diethylformamide (DEF), N-methylpyrrolidone (NMP), N-ethylpyrrolidone (NEP), N, N-dimethylmethoxyacetamide, dimethylsulfoxide, pyridine, dimethylsulfone, Hexamethylphosphoramide, tetramethylurea, N-methylcaprolactam, tetrahydrofuran, m-dioxane, P-dioxane, 1,2-dimethoxyethane, bis (2-methoxyethyl) ether, 1,2-bis (2-methoxy). Ethoxy) ethane, bis [2- (2-methoxyethoxy)] ether, Equamide M100, Equamid B100, etc., of which one or a mixture of two or more is used.

For example, the organic solvent used for the polymerization reaction between the diamine and the acid dianhydride includes a solvent having a positive partition coefficient (Log P value) at 25 ° C., and the organic solvent has a boiling point of 300. It is below ° C., and more specifically, the partition coefficient Log P value is 0.01 to 3, or 0.01 to 2, or 0.1 to 2.

The partition coefficient is calculated using the ACD / Log P model of the ACD / Percepta platform of ACD / Labs, and the ACD / Log P model is a QSPR (Quantitative Structure) method using the 2D structure of the molecule. Use the underlying algorithm of. The partition coefficient (Log P value) of a typical solvent at 25 ° C. is as follows.

The solvent having a positive partition coefficient (Log P) is dimethylpropionamide (DMPA), diethylpropionamide (DEPA), N, N-diethylacetamide (N, N-diethylacetylamide, DEAc), N, N-diethylformamide. (N, N-diethylformamide, DEF), N-ethylpyrrolidone (NEP), one or more selected from these, in particular, an amide-based solvent.

The method of reacting the tetracarboxylic acid dianhydride with diamine is carried out by a usual method for producing a polyimide resin precursor polymerization such as solution polymerization, and specifically, after dissolving diamine in an organic solvent, as a result. It can be produced by adding tetracarboxylic acid dianhydride to the obtained mixed solution and polymerizing it.

The polymerization reaction is carried out under an inert gas or nitrogen stream and can be carried out under anhydrous conditions.

Further, at the time of the polymerization reaction, the reaction temperature is carried out at -20 to 80 ° C, preferably 0 to 80 ° C. If the reaction temperature is excessively high, the reactivity becomes high, the molecular weight becomes excessively large, and the viscosity of the precursor composition increases, which is disadvantageous in the process.

The polyimide resin precursor composition containing polyamic acid is in the form of a solution dissolved in an organic solvent, and has such a form, for example, when the polyimide resin precursor is synthesized in an organic solvent. , The solution may be the obtained reaction solution itself, or the reaction solution may be diluted with another solvent. Further, when the polyimide resin precursor is obtained as a solid powder, it may be dissolved in an organic solvent to make a solution. For example, at the time of the polymerization reaction, an organic solvent having a positive Log P can be used, and as the organic solvent to be mixed thereafter, an organic solvent having a negative Log P can be mixed and used.

According to one example, the solid content of the composition is adjusted by adding an organic solvent so that the content of the total polyimide resin precursor is 8 to 25% by weight, preferably 10 to 25% by weight. More preferably, it can be adjusted to 10 to 20% by weight or less.

Alternatively, the polyimide resin precursor composition is adjusted to have a viscosity of 2,000 cP or more, 3,000 cP or more, or 4,000 cP or more, and the viscosity of the polyimide resin precursor composition is 10. It is desirable to adjust the viscosity so that it has a viscosity of 000 cP or less, preferably 9,000 cP or less, and more preferably 8,000 cP or less. When the viscosity of the polyimide resin precursor composition exceeds 10,000 cP, the efficiency of defoaming decreases during the processing of the polyimide film, so that not only the efficiency in the process but also the produced film generates bubbles. The surface roughness is poor, and the electrical, optical, and mechanical properties are deteriorated.

Further, the molecular weight of the polyimide according to the present invention has a weight average molecular weight of 10,000 to 200,000 g / mol, 20,000 to 100,000 g / mol, or 30,000 to 100,000 g / mol. .. Further, it is desirable that the molecular weight distribution (Mw / Mn) of the polyimide according to the present invention is 1.1 to 2.5. The weight average molecular weight Mw and the water average molecular weight Mn are determined by standard polystyrene conversion using gel permeation chromatography. If the weight average molecular weight or the molecular weight distribution of the polyimide is out of the above range, it may be difficult to form the film, or the characteristics of the polyimide-based film such as transmittance, heat resistance and mechanical properties may be deteriorated.

Subsequently, the transparent polyimide film can be produced by imidizing the polyimide resin precursor obtained as a result of the polymerization reaction.

According to one embodiment, the polyimide film composition obtained as described above is a step of applying the polyimide resin precursor composition onto a substrate; and a step of heat-treating the applied resin precursor composition; The polyimide film can be manufactured through the above.

At this time, as the substrate, a glass, a metal substrate, a plastic substrate, or the like is used without particular limitation, and among them, among the imidization and curing steps for the polyimide resin precursor, the heat and chemical stability are excellent, and the substrate is separately used. It is desirable to use a glass substrate that can be easily separated from the formed polyimide-based film after curing without any damage even without the release agent treatment.

Further, the coating step is carried out by a normal coating method, and specifically, a spin coating method, a bar coating method, a roll coating method, an air knife method, a gravure method, a reverse roll method, a kiss roll method, a doctor blade method, and a spray. A method, a dipping method, a brush method, etc. may be used. Among them, it is more preferable to carry out by a casting method capable of continuous steps and increasing the imidization rate of polyimide.

Further, the polyimide resin precursor composition can be applied onto the substrate within a thickness range that allows the polyimide film finally produced to have a thickness suitable for a display substrate.

Specifically, it can be applied in an amount having a thickness of 10 to 30 μm. After applying the polyimide resin precursor composition, a drying step for removing the solvent present in the polyimide resin precursor composition is selectively further carried out prior to the curing step.

The drying step is carried out by a usual method, and specifically, is carried out at a temperature of 140 ° C. or lower, or 80 to 140 ° C. If the temperature at which the drying step is carried out is 80 ° C., the drying step becomes long, and if it exceeds 140 ° C., imidization partially proceeds and it is difficult to form a polyimide film having a uniform thickness.

Subsequently, the polyimide resin precursor composition is applied to a substrate and heat-treated on an IR oven, a hot air oven or a hot plate, in which the heat treatment temperature is in the range of 300 to 500 ° C, preferably 320 to 480 ° C. It is also possible to proceed by a multi-step heat treatment within the above temperature range. The heat treatment step may proceed for 20 to 70 minutes, preferably 20 to 60 minutes.

After that, the polyimide film can be manufactured by peeling the polyimide film formed on the substrate from the substrate by a usual method.

The polyimide film produced as described above has a modulus of 2.2 GPa or less, for example, 0.1 to 2.0 GPa, and a stretch ratio of 20% or more. If the elastic modulus is 0.1 GPa, the rigidity of the film is low and it is easily broken by an external impact, and if the elastic modulus exceeds 2.2 GPa, the rigidity of the film is excellent, but it is sufficiently flexible. There is a risk of problems such as the inability to ensure sex.

Further, the polyimide film according to the present invention has a glass transition temperature (Tg) of 230 ° C. or higher.

Further, the polyimide film according to the present invention has excellent thermal stability due to temperature changes, and for example, the coefficient of thermal expansion after n + 1 times of heating and cooling steps in a temperature range of 100 to 400 ° C. is -10 to 100 ppm / ° C. It is preferably a value of −7 to 90 ppm / ° C, more preferably 80 ppm / ° C or less.

Further, polyimide films according to the invention, by the thickness retardation _{(R th)} has a value of -100 to + 100 nm, illustrates the isotropic, visual sensitivity is improved.

According to one embodiment, the polyimide film has an adhesive force with a carrier substrate of 5 gf / in or more, preferably 10 gf / in or more.

Further, in the present invention, a precursor composition containing a diamine containing DDS and an amine-terminated methylphenylsiloxane oligomer and a polyamic acid produced by using two or more kinds of tetracarboxylic acid dianhydrides as a polymerization component is provided on a carrier substrate. A step of forming a polyimide film by heating the precursor composition to imidize the polyamic acid; a step of forming an element on the polyimide film; and a polyimide film on which the element is formed. Provided is a step of manufacturing a flexible device including the step of peeling the carrier substrate from the carrier substrate.

In particular, the manufacturing process of the flexible device may include a LTPS thin film manufacturing step, an ITO thin film manufacturing step, or an Oxide thin film manufacturing step.

_{For example, a step of forming a blocking layer containing SiO 2} on a polyimide film; a step of depositing an a—Si (amorphous silicon) thin film on the blocking layer; a step of depositing the vapor-deposited a—Si thin film at a temperature of 450 ± 50 ° C. After the LTPS thin film manufacturing step including the dehydrogenation annealing step of heat treatment with the above; and the step of crystallizing the a-Si thin film with an excima laser or the like; Flexible devices including

The pores in the polyimide film can induce cracks on the inorganic film (polysilicon thin film) by a high-temperature heat treatment step during the LTPS TFT step. Therefore, according to the present invention, the ratio of pores in such a polyimide film is adjusted / adjusted to 1% or less, and the average size of the phase separation domain is adjusted to 10 nm or less to generate cracks in the inorganic film layer. It can be suppressed or significantly reduced.

The oxide thin film process is heat-treated at a lower temperature than the process using silicon. For example, the heat treatment temperature of the ITO TFT process is 200 ° C. ± 50 ° C., and the heat treatment temperature of the Oxide TFT process is 320 ° C. ± 50 ° C. ℃.

Hereinafter, examples of the present invention will be described in detail so that those skilled in the art can easily carry out the invention. However, the present invention can be embodied in a variety of different forms and is not limited to the examples described herein.

<Example 1> BPDA-PMDA (6: 4) / DDS / DPS-DMS 10 wt%

After filling DEAc (N, N-diethylacetamide) in the reactor through which the nitrogen stream flows, 4,4'-DDS (4,4'-diaminodiphenyl sulfone) while keeping the temperature of the reactor at 25 ° C. 0.15096 mol was added at the same temperature and dissolved. PMDA 0.0611 mol and BPDA (3,3', 4,4'-biphenyltetracarboxylic acid dianhydride) 0.0917 mol were added to the solution to which DDS was added at the same temperature, and the mixture was stirred for 24 hours and then stirred. 0.00199 mol of both-terminal amine-modified DPS-DMS (diphenylsyloxane-dimethylsiloxane co-oligomer, molecular weight 4360 g / mol) was added, and the mixture was stirred at 80 ° C. for 4 hours. The oil bath was then removed and returned to room temperature to give a clear DEAc solution of polyamic acid.

<Examples 2 to 12> BPDA-PMDA / DDS / DPS-DMS

A transparent DEAc solution of polyamic acid was prepared by the same method as in Example 1 except that the mol ratios of BPDA and PMDA and the amount of DPS-DMS added were changed as shown in Tables 1 to 3. ..

<Examples 13 to 15>

Polyamide acid solutions were prepared in the same manner as in Example 9, except that the DPS-DMS contents were 25 wt%, 20 wt% and 5 wt%, respectively.

<Comparative Example 1> BPDA-PMDA (6: 4) -DMS

After filling DEAc in the reactor through which the nitrogen stream flows, 4,4'-DDS 0.08497 mol was added and dissolved at the same temperature while the temperature of the reactor was maintained at 25 ° C. PMDA 0.03399 mol and BPDA 0.005098 mol were added to the solution to which DDS was added at the same temperature, and the mixture was stirred for 24 hours to obtain a clear polyamic acid DEAc solution.

<Comparative Example 2> BPDA-PMDA (6: 4) / TFMB / DPS-DMS 10 wt%

After filling DEAc in the stirrer through which the nitrogen stream flows, 0.1121 mol of TFMB (2,2'-bis (trifluoromethyl) benzidine) was added at the same temperature while the temperature of the reactor was maintained at 25 ° C. Dissolved. PMDA 0.0453 mol and BPDA 0.0679 mol were added to the solution to which TFMB was added at the same temperature, and after stirring for 24 hours, both terminal amine-modified DPS-DMS (molecular weight 4360 g / mol) 0.00168 mol was added. , 80 ° C. for 4 hours. The oil bath was then removed and returned to room temperature to give a clear DEAc solution of polyamic acid.

<Comparative Example 3> BPDA-PMDA (6: 4) / TFMB / DPS-DMS 15 wt%

A transparent DEAc solution of polyamic acid was produced by the same method as in Comparative Example 2 except that the amount of DPS-DMS added was changed to 15 wt%.

<Comparative Example 4> BPDA-PMDA (6: 4) / TFMB / DPS-DMS 18 wt%

A transparent DEAc solution of polyamic acid was produced by the same method as in Comparative Example 2 except that the amount of DPS-DMS added was changed to 18 wt%.

<Experimental Example 1>

The respective polyimide resin precursor solutions produced from Examples 1 to 12 and Comparative Examples 1 to 4 were spin-coated on a glass substrate. The glass substrate coated with the polyimide precursor solution is placed in an oven, heated at a rate of 5 ° C./min, and held at 80 ° C. for 30 minutes and 400 ° C. for 30 minutes to proceed with the curing process to obtain a polyimide film. Manufactured. The physical characteristics of each film were measured and shown in Tables 1 to 3 below.

<Viscosity>

The viscosity of the solution is the time when 5 ml of PAA solution is placed in a container with a late rheometer (model name: LVDV-1II Ultra, manufactured by Blockfield), the spindle is lowered, the rpm is adjusted, and the torque becomes 80. After waiting for 1 minute at, the viscosity value when there was no torque change was measured. At this time, the spindle used was 52Z, and the temperature was 25 ° C.

<Distribution rate of pores>

After fixing the image of the polyimide film measured by FIB-SEM at 100,000 magnification to 100 mm x 80 mm, the area was subdivided into 2 mm x 2 mm, and the area where the pores exist was calculated by the ratio based on the total of 2000 areas (Fig.). 1).

FIG. 1 shows a method for measuring the stomatal distribution rate using the FIB-SEM image of the film according to Example 4. Since there are two regions where pores are present, the pore distribution rate was 0.1%.

Pore distribution rate (%) = [2/2000] x100 = 0.1%

FIG. 3 shows the FIB-SEM of the polyimide film of Comparative Example 1, which is a polyimide containing no DPS-DMS. As can be seen from FIG. 3, in the case of the polyimide containing no DPS-DMS, it can be seen that no pores are generated in the film.

4A to 4C are FIB-SEM images of the polyimide films of Examples and Comparative Examples due to changes in the DPS-DMS content. When DPS-DMS is contained, it can be seen that in the polyimide film of the comparative example, the amount of pores generated increases significantly as the content of DPS-DMS increases, but in the case of the polyimide film of the example containing DDS as a diamine. It can be seen that, despite the increase in the content of DPS-DMS, the generation of pores hardly occurs. Specifically, FIG. 4A shows a comparison of the films of Example 4 and Comparative Example 4 in which the content of DPS-DMS is 18 wt%. In the case of Example 4, it possesses two pore regions and has a pore distribution rate of 0.1%, while in the case of Comparative Example 4, it shows a very high pore distribution rate of 21%, and is a comparative example. In the case of 2, a pore distribution rate of 4.6% was shown.

<Yellowness (YI)>

Yellowness (YI) was measured with Color Eye 7000A.

<Haze>

Haze was measured by the method according to ASTM D1003 using Haze Meter HM-150.

<Transparency>

The transmittance was measured with a transmittance meter (model name: HR-100, manufactured by Murakami Color Research Laboratory) based on JIS K 7105 for wavelengths of 450 nm, 550 nm and 633 nm.

<Thickness direction phase difference (R _th )>

Thickness retardation _{(R th)} was measured using Axoscan. After cutting the film to a certain size and measuring the thickness, the phase difference was measured by Axoscan, and the measured thickness was input while being corrected in the C-platate direction in order to compensate for the phase difference value. The measurement wavelength was 550 nm.

<Glass transition temperature (Tg) and coefficient of thermal expansion (CTE)>

After preparing the film to a size of 5x20 mm, the sample is loaded using accessories. The length of the film actually measured was the same as 16 mm. After setting the tensile force of the film to 0.02 N and proceeding with the primary temperature rise step at a temperature rise rate of 5 ° C./min in a temperature range of 100 to 400 ° C., 4 ° C./at a temperature range of 400 to 100 ° C. After cooling at a cooling rate of min, the secondary heating step is performed again at a heating rate of 5 ° C./min in a temperature range of 100 to 450 ° C., and the mode of the thermal expansion change is described by TMA (TA). It was measured by Q400).

At this time, the inflection point observed in the temperature rise section in the secondary temperature rise step was defined as Tg.

<Pyrolysis temperature (Td_1%) and weight loss rate (%)>

Using TGA, the temperature when the weight loss rate of the polymer was 1% was measured in a nitrogen atmosphere.

The weight loss rate when held at 350 ° C. for 60 minutes was measured.

The weight loss rate when held at 380 ° C. for 60 minutes was measured.

<Modulus, tensile strength and draw ratio>

A film having a length of 5 mm x 50 mm and a thickness of 10 μm was pulled at a speed of 10 mm / min with a tensile tester (manufactured by Instron Co., Ltd .: Instron 3342), and modulus (GPa), tensile strength (MPa), and stretch ratio (%) were measured. ..

<Measurement of residual stress and Bow value>

The resin composition was applied by a spin coater on a 6-inch silicon wafer with a thickness of 525 μm in which the amount of warpage of the wafer was measured in advance using a residual stress measuring device (FLX2320 manufactured by TENCOR), and Koyo Lindbergh was used. Using an oven manufactured by the same company, heat curing treatments at 250 ° C./30 min and 400 ° C./60 min were carried out in a nitrogen atmosphere, and after curing, a silicon wafer to which a resin film having a thickness of 10 μm was attached was manufactured. The amount of warpage of this wafer was measured using a residual stress measuring device, and the residual stress generated between the silicon wafer and the resin film was measured by the Real Bow value.

[Table 1]

[Table 2]

[Table 3]

[Table 4]

As can be seen from Tables 1 to 4, in the polyimide film according to the examples, DDS is used together with DPS-DMS as a diamine, and the pore distribution ratio in the polyimide film is controlled to 1% or less, so that the modulus is 2. It is possible to provide a polyimide film having a value of 2 GPa or less and having an appropriate rigidity and elasticity having a draw ratio of 20% or more.

<Experimental Example 2>

The respective polyimide film compositions produced from Example 9, Comparative Example 1 and Comparative Example 2 were spin-coated on a glass substrate. The glass substrate coated with the polyimide precursor solution is placed in an oven, heated at a rate of 5 ° C./min, and held at 80 ° C. for 30 minutes and 400 ° C. for 30 minutes to proceed with the curing process to obtain a polyimide film. Manufactured.

The phase-separated domain distribution ratio of the polyimide film was measured by the method shown in FIG. The FIB-SEM image was fixed at 100,000 magnification to 100 mm x 70 mm, the area was subdivided into 2 mm x 2 mm, and the area was divided into white and black areas based on a total of 1750 areas. The ratio of the white area was calculated from the total area.

When the phase-separated domain distribution rate of Example 9 is measured by the method as described above, 650 white regions are present out of a total of 1750 regions, and therefore, a phase-separated domain distribution rate of about 32% is shown. rice field.

The film of Comparative Example 1 did not contain a DPS-DMS structure and, as shown in FIG. 3, did not show phase separation. In the film of Comparative Example 2, by using TFMB instead of DDS as the diamine, a large amount of nanopores were generated in the film, and the presence of the phase separation domain could not be confirmed.

On the other hand, FIG. 5 shows a FIB-SEM image (x100,000) of a polyimide film according to Example 11 (DPS-DMS 15 wt%) and Examples 13 to 15 (DPS-DMS 25 wt%, 20 wt%, 5 wt%, respectively). ). It can be confirmed that the phase-separated domains are uniformly distributed with almost no pores in the film.

<Experimental example 3>

_{SiO 2} was vapor-deposited at 350 ° C. on the polyimide films produced from Example 4, Comparative Example 2 and Comparative Example 4. The thickness of the SiO ₂ layer was adjusted to 2000 Å. After that, _{the polyimide film on which the SiO 2} layer was formed was heated at 380 ° C. for 2 hours for heat treatment.

FIG. 6 is a photograph of a polyimide film on which _{two layers of SiO are formed. As can be seen from FIG. 6, when the SiO 2} layer was vapor-deposited on the films of Comparative Example 2 and Comparative Example 4 having a pore distribution ratio of 1% or more and then heat-treated, cracks were generated in the _{SiO 2 layer.} As in Example 4, it can be seen that no cracks are generated in _{the SiO 2} layer deposited on the film having pores of 1% or less (0.1%).

As described above, when a specific part of the content of the present invention is described in detail, such a specific description is merely a desirable embodiment for those skilled in the art, and this does not limit the scope of the present invention. The point is clear. Accordingly, the substantive scope of the invention is defined by the claims and their equivalents.

Claims (14)

A diamine component containing a diamine having the structure of the following chemical formula 1 and an amine-terminated methylphenylsiloxane oligomer, and
A dianhydride component containing two or more tetracarboxylic dianhydrides,
A film containing a polymerization and imidization product of a polymerization component containing
The pore distribution rate in the film is 1% or less.
Polyimide film:
[Chemical formula 1]

.. The pore distribution ratio was calculated as the ratio of the region where the pores exist in the entire region when the 100,000 magnification FIB-SEM image of the polyimide film was fixed at 100 mm × 80 mm and subdivided into 2 mm × 2 mm.
The polyimide film according to claim 1. A diamine component containing a diamine having the structure of the following chemical formula 1 and an amine-terminated methylphenylsiloxane oligomer, and
A dianhydride component containing two or more tetracarboxylic dianhydrides,
A polyimide film containing a polymerization of polymerization components and an imidization product.
A plurality of domains derived from the amine-terminated methylphenylsiloxane oligomer are dispersed in the polyimide matrix derived from the diamine of the following chemical formula 1.
The average size of the plurality of domains is 10 nm or less.
Polyimide film:
[Chemical formula 1]

.. The distribution rate of the domain is 25 to 60%, and the distribution rate is 25 to 60%.
The distribution ratio of the domain is determined by fixing the 100,000 magnification FIB-SEM image of the polyimide film to 100 mm × 70 mm, subdividing it into 2 mm × 2 mm, dividing it into a white region and a black region, and then determining the ratio of the white region in the entire region. Calculated,
The polyimide film according to claim 3. The amine-terminated methylphenylsiloxane oligomer has the structure of Chemical Formula 2 below.
The polyimide film according to any one of claims 1 to 4.
[Chemical formula 2]

In the chemical formula 2,
p and q are mole fractions,
When p + q = 100,
p is 70 to 90,
q is 10 to 30. The dianhydride component comprises BPDA and PMDA.
The polyimide film according to any one of claims 1 to 5. The dianhydride component contains BPDA and PMDA in a mol ratio of 6: 4 to 8: 2.
The polyimide film according to claim 6. The polymerization component is 5 to 30% by weight based on the total weight of the polymerization component of the amine-terminated methylphenylsiloxane oligomer.
The polyimide film according to any one of claims 1 to 7. The polymerization component contains 1 to 10 mol% of an amine-terminated methylphenylsiloxane oligomer based on the total diamine component.
The polyimide film according to any one of claims 1 to 8. The modulus of the polyimide film is 2.2 GPa or less, and the polyimide film has a modulus of 2.2 GPa or less.
The draw ratio is 20% or more.
The polyimide film according to any one of claims 1 to 9. The glass transition temperature (Tg) of the polyimide film is 230 ° C. or higher.
The polyimide film according to any one of claims 1 to 10. The polyimide film according to any one of claims 1 to 11 is included as a substrate.
Flexible device. A resin precursor composition is produced by reacting a diamine component containing a diamine having the structure of the following chemical formula 1 and an amine-terminated methylphenylsiloxane oligomer with a dianhydride component containing two or more types of tetracarboxylic dianhydrides. And the stage to do
At the stage of applying the produced resin precursor composition onto the carrier substrate,
The step of forming the polyimide film according to any one of claims 1 to 11 by heating and imidizing the resin precursor composition.
The stage of forming an element on the polyimide film and
At the stage of peeling the polyimide film on which the element is formed from the carrier substrate,
including,
Flexible device manufacturing process:
[Chemical formula 1]

.. The manufacturing step comprises one or more steps selected from the group consisting of a LTPS thin film manufacturing step, an ITO thin film manufacturing step and an Oxide thin film manufacturing step.
The manufacturing process of the flexible device according to claim 13.

Images