RU2796817C2 - Acid anhydride compound, polyimide-based polymer, polymer film and optical device for which they are used - Google Patents

Abstract

FIELD: organic chemistry.

SUBSTANCE: invention relates to polymers based on polyimide. A polymer based on polyimide is proposed for obtaining a polymer film containing a repeating unit selected from the group consisting of units represented by chemical formulas 3, 4 and 5. Also a polymer film for the manufacture of an optical device, including a cured polymer product based on polyimide, and an optical device obtained using it are proposed.

EFFECT: proposed polymer makes it possible to obtain a film with an excellent combination of transparency and heat resistance.

4 cl, 1 tbl, 6 ex

Description

The field of technology to which the invention belongs

The present invention relates to an acid anhydride compound that can be used to synthesize a polyimide-based polymer excellent in transparency, high heat resistance and low retardation, and a polyimide-based polymer, a polymer film and an optical device for which they are used.

Prerequisites for the creation of the invention

The market for display substrates is rapidly changing with flat panel displays (FPDs) that are easy to manufacture with a large area and can be reduced in thickness and weight. Such flat panel displays include liquid crystal displays (LCDs), organic light emitting displays (OLEDs), and electrophoretic devices.

In particular, in an attempt to further expand the application and use of flat panel displays, in recent years, attention has been focused on so-called flexible display devices and the like, in which flexible substrates are used for flat panel displays. The use of such flexible display devices is particularly being considered in connection with mobile devices such as smartphones, and their fields of application are gradually expanding.

In particular, the aromatic polyimide resin is a polymer having a substantially amorphous structure, exhibits excellent heat resistance, chemical resistance, electrical properties, and dimensional stability due to its rigid chain structure, and can have flexibility applicable to flexible displays, and thus is widely used. as electrical/electronic material.

However, the polyimide resin has a dark brown color due to the charge transfer complex (CTC) of the pi electrons present in the imide chain, so it is difficult to make it transparent. Thus, flexible electronics technology has been developed to produce electronic devices and systems that are inexpensive and flexible, yet have transparent properties.

In particular, a method has been proposed in which a trifluoromethyl group (-CF ₃ ) capable of imparting an electron-withdrawing effect is introduced as a substituent in a monomer compound used for the synthesis of a polyimide resin, and transparency is ensured by suppressing the formation of CTC (Charge Transfer Complex) pi -electrons present in the imide chain.

However, with respect to a polyimide substituted with a trifluoromethyl group (-CF ₃ ), there are difficulties in providing sufficient heat resistance. Thus, when it is used as a plastic substrate, the problem is that the plastic substrate may be damaged by heat treatment of the metal layer formed on the plastic substrate.

In addition, the polyimide substituted with a trifluoromethyl group (-CF ₃ ) has a high coefficient of thermal expansion. Thus, when it is used as a plastic substrate, a problem is that deformation of the thin metal film formed on the plastic substrate occurs.

Therefore, there is a need to develop a monomeric acid anhydride compound for polyimide synthesis capable of realizing stable heat resistance properties together with excellent transparency.

Detailed description of the invention

Technical task

An object of the present invention is to provide an acid anhydride compound that can be used to synthesize a polyimide-based polymer having excellent transparency, high heat resistance and low retardation.

Another object of the present invention is to provide a polyimide-based polymer synthesized from said acid anhydride compound.

Yet another object of the present invention is to provide a polymeric film and an optical device for which said polyimide-based polymer is used.

Technical solution

In one aspect of the invention, an acid anhydride represented by the following chemical formula 1 is provided.

[Chemical formula 1]

In the chemical formula 1, X ₁ and X ₂ are the same or different from each other, and each independently represents a tetravalent organic group, R ₁ and R ₂ are the same or different from each other, and each independently represents any of a substituted or unsubstituted alkyl group , containing 1-20 carbon atoms, a substituted or unsubstituted alkoxy group containing 1-20 carbon atoms, a substituted or unsubstituted cycloalkyl group containing 3-20 carbon atoms, a substituted or unsubstituted aryl group containing 6-30 carbon atoms, or substituted or unsubstituted heteroaryl group containing 3-30 carbon atoms, and L ₁ is any value selected from a single bond, -O-, -CO-, -S-, -SO ₂ -, -C(CH ₃ ) ₂ -, - C(CF ₃ ) ₂ -, -CONH-, -COO-, -(CH ₂ ) _y -, -O(CH ₂ ) _y O-, -O(CH ₂ ) _y -, -NH-, -NH( CH ₂ ) _y -NH-, -NH(CH ₂ ) _y O-, -OCH ₂ -C(CH ₃ ) ₂ -CH ₂ O-, -COO-(CH ₂ ) _y -OCO-, or -OCO- (CH ₂ ) _y -COO- where, in L ₁ , y is an integer having a value from 1 to 10.

In another aspect of the invention, there is provided a polyimide-based polymer comprising at least one repeat unit selected from the group consisting of a repeat unit represented by the following chemical formula 3, a repeat unit represented by the following chemical formula 4, and a repeat unit represented by the following chemical formula 5.

[Chemical formula 3]

[Chemical formula 4]

[Chemical Formula 5]

In chemical formulas 3-5, at least one of R ₁₁ and R ₁₂ is an alkyl group containing 1-10 carbon atoms and the other is hydrogen, X ₃ - X ₅ are the same or different from each other and each independently represents is a functional group represented by the following chemical formula 6, Y ₃ - Y ₅ are the same or different from each other and each independently represents a divalent organic group,

[Chemical formula 6]

where, in the chemical formula 6, X ₁ and X ₂ are the same or different from each other and each independently represents a tetravalent organic group, R ₁ and R ₂ are the same or different from each other and each independently represents any of substituted or unsubstituted an alkyl group containing 1-20 carbon atoms, a substituted or unsubstituted alkoxy group containing 1-20 carbon atoms, a substituted or unsubstituted cycloalkyl group containing 3-20 carbon atoms, a substituted or unsubstituted aryl group containing 6-30 carbon atoms, or substituted or unsubstituted heteroaryl group containing 3-30 carbon atoms, and L ₁ is any value selected from a single bond, -O-, -CO-, -S-, -SO ₂ -, -C(CH ₃ ) ₂ - , -C(CF ₃ ) ₂ -, -CONH-, -COO-, -(CH ₂ ) _y -, -O(CH ₂ ) _y O-, -O(CH ₂ ) _y -, -NH-, - NH(CH ₂ ) _y -NH-, -NH(CH ₂ ) _y O-, -OCH ₂ -C(CH ₃ ) ₂ -CH ₂ O-, -COO-(CH ₂ ) _y -OCO-, or - OCO-(CH ₂ ) _y -COO- where, in L ₁ , y is an integer having a value from 1 to 10.

In yet another aspect of the invention, a polymeric film is provided, comprising a cured polyimide-based polymer product.

And yet another aspect of the invention provides an optical device comprising a polymer film.

Hereinafter, an acid anhydride compound, a polyimide-based polymer, a polymer film, and an optical device for which they are used according to specific embodiments of the present invention will be described in more detail.

Unless otherwise indicated in the present description, the technical terms used are only intended to describe specific embodiments and are not intended to limit the present invention.

The singular forms defined by the articles ʺaʺ and ʺanʺ are also intended to include plural forms, unless the context clearly indicates otherwise.

As used herein, the term "comprising" or "comprising" indicates a particular feature, scope, integer, step, action, element, and/or component, but does not preclude the addition of another specific feature, scope, integer, step, action, element, component, and/or groups.

Terms that include serial numbers, such as "first", "second", etc., are used only for the purpose of distinguishing one component from another component and are not limited to serial numbers. For example, the first component may be listed as the second component, or similarly, the second component may be listed as the first component, without departing from the scope of the present invention.

In the context of this application, the weight average molecular weight is measured as follows: using a Waters Alliance 2695 device equipped with an Agilent Mixed B column, temperature for determination 40°C, solvent tetrahydrofuran, flow rate 1.0 ml/min, sample prepared at a concentration of 1 mg/10 ml and then served in an amount of 100 μl, and the Mw value can be determined using calibration curves obtained from a polystyrene standard. The molecular weight of polystyrene standards can be nine kinds: 2000/10000/30000/70000/200000/700000/2000000/4000000/10000000.

In the context of the present application, the term "substituted" means that other functional groups instead of the hydrogen atom in the compound are bonded, and the position to be substituted is not limited, provided that the position in which the hydrogen atom is substituted, i.e. a position in which it can be substituted by a substituent. When two or more substituents are present, the two or more substituents may be the same or different from each other.

In the context of this application, the term "substituted or unsubstituted" means that the group is unsubstituted or substituted with one or more substituents selected from the group consisting of deuterium; halogen groups; cyano group; nitro groups; hydroxy groups; carbonyl group; an ester group; imide group; amide group; primary amino group; carboxy groups; sulfonic acid groups; sulfonamide group; phosphine oxide group; alkoxy groups; aryloxy groups; alkylthio groups; arylthioxy groups; alkylsulfoxy groups; arylsulfoxy groups; silyl group; boron groups; an alkyl group; cycloalkyl group; alkenyl group; an aryl group; an aralkyl group; aralkenyl group; an alkylaryl group; alkoxysilylalkyl group; arylphosphine group; or a heterocyclic group containing at least one of N, O and S atoms, or is unsubstituted or substituted by a substituent to which two or more of the substituents exemplified above are bonded. For example, "a substituent to which two or more substituents are attached" may be a biphenyl group. That is, the biphenyl group may also be an aryl group and may be understood as a substituent to which two phenyl groups are attached.

As used herein, "aromatic" is a characteristic that satisfies Hückel's rule, and a system can be defined as aromatic when it satisfies all of the following three conditions, according to Hückel's rule.

1) There must be 4n+2 electrons that are fully conjugated empty p orbitals, unsaturated bonds, unpaired electron pairs, etc.

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

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

In the present specification, a multivalent functional group is a residue in which a plurality of hydrogen atoms bonding to an arbitrary compound have been removed, and, for example, it may be a divalent functional group, a trivalent functional group, and a tetravalent functional group. By way of example, a tetravalent functional group derived from cyclobutane means a residue in which any four hydrogen atoms associated with cyclobutane have been removed.

In the present description, examples of halogen can be fluorine, chlorine, bromine and iodine.

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

In the present specification, a haloalkyl group means a functional group in which the above-described alkyl group is substituted with halogen, and examples of the halo group include fluorine, chlorine, bromine, and iodine. The haloalkyl group may be substituted or unsubstituted.

As used herein, a cycloalkyl group is a monovalent functional group derived from a cycloalkane, which may be monocyclic or polycyclic. The number of carbon atoms is not particularly limited, but is 3 to 20. According to one embodiment, the number of carbon atoms of the cycloalkyl group is 3 to 10. Specific examples include cyclopropyl, cyclobutyl, cyclopentyl, 3-methylcyclopentyl, 2,3-dimethylcyclopentyl , cyclohexyl, 3-methylcyclohexyl, 4-methylcyclohexyl, 2,3-dimethylcyclohexyl, 3,4,5-trimethylcyclohexyl, 4-tert-butylcyclohexyl, cycloheptyl, cyclooctyl, bicyclo[2.2.1]heptyl and the like, but not limited to this. The cycloalkyl group may be substituted or unsubstituted, and when it is substituted, examples of the substituent are as described above.

In the present description, an alkylene group is a divalent functional group derived from an alkane, and the description of an alkyl group as defined above can be applied to it, except that it is a divalent functional group. For example, the alkylene group is straight or branched chain and may include a methylene group, an ethylene group, a propylene group, an isobutylene group, a sec-butylene group, a t-butylene group, a pentylene group, a hexylene group, or the like. The alkylene group may be substituted or unsubstituted, and when substituted, examples of the substituent are as described above.

In the present specification, a cycloalkylene group is a divalent functional group derived from a cycloalkane, and the description of a cycloalkylene group as defined above can be applied to it, except that it is a divalent functional group. The cycloalkylene group may be substituted or unsubstituted, and when substituted, examples of the substituent are as described above.

In the present specification, an alkoxy group is a functional group to which the above alkyl group is linked at one end of an ether group (-O-), and the description of an alkyl group as defined above can be applied to it, except that it is an ether-linked functional group. group (-O-). Examples may include linear, branched or cyclic groups. The number of carbon atoms in the alkoxy group is not particularly limited, but is preferably 1 to 20. Specific examples include methoxy, ethoxy, n-propoxy, isopropoxy, isopropoxy, n-butoxy, isobutoxy, tert-butoxy, sec-butoxy, n-pentyloxy , neopentyloxy, isopentyloxy, n-hexyloxy, 3,3-dimethylbutyloxy, 2-ethylbutyloxy, n-octyloxy, n-nonyloxy, n-decyloxy, cycloheptoxy, benzyloxy, p-methylbenzyloxy, and the like, but are not limited to these. The alkoxy group may be substituted or unsubstituted.

In the present specification, the aryl group is a monovalent arene-derived functional group, and is not specifically limited, but preferably has 6 to 20 carbon atoms, and may be a monocyclic aryl group or a polycyclic aryl group. The aryl group may be a phenyl group, a biphenyl group, a terphenyl group, or the like. as a monocyclic aryl group, but is not limited to this. Examples of the polycyclic aryl group include, but are not limited to, a naphthyl group, an anthracenyl group, a phenanthryl group, a pyrenyl group, a perylene group, a chryzenyl group, and a fluorenyl group.

As used herein, a heteroaryl group includes one or more atoms other than carbon, that is, one or more heteroatoms, and in particular, a heteroatom may include one or more atoms selected from the group consisting of O, N, Se, and S, and etc. The number of carbon atoms is not particularly limited, but is preferably 4 to 20, and the heteroaryl group may be monocyclic or polycyclic. Examples of the heterocyclic group include thiophene group, furanyl group, pyrrole group, imidazolyl group, thiazolyl group, oxazolyl group, oxadiazolyl group, pyridyl group, bipyridyl group, pyrimidyl group, triazinyl group, triazolyl group, acridyl group, pyridazinyl group, pyrazinyl group, quinolinyl group group, quinazolinyl group, quinoxalinyl group, phthalazinyl group, pyridopyrimidyl group, pyridopyrazinyl group, pyrazinopyrazinyl group, isoquinolinyl group, indolyl group, carbazolyl group, benzoxazolyl group, benzimidazolyl group, benzothiazolyl group, benzocarbazolyl group, benzothiophene group, di a benzothiophene group, a benzofuranyl group, phenanthrolinyl group (phenanthroline), thiazolyl group, isoxazolyl group, oxadiazolyl group, thiadiazolyl group, benzothiazolyl group, phenothiazinyl group, aziridyl group, azaindolyl group, isoindolyl group, indazolyl group, purine group (purine), pteridyl group (pteridine), beta- but not limited to a carboline group, a naphthyridyl group (naphthyridine), a terpyridyl group, a phenazinyl group, an imidazopyridyl group, a pyropyridyl group, an azepine group, a pyrazolyl group, a dibenzofuranyl group, and the like. The heteroaryl group may be substituted or unsubstituted, and when substituted, examples of the substituent are as described above.

In the present description, an arylene group is a divalent functional group derived from an arene, and the description of an aryl group as defined above can be applied to it, except that it is a divalent functional group. Examples include a phenylene group, a biphenylene group, a terphenylene group, a naphthalene group, a fluorenyl group, a pyrenyl group, a phenanthrenyl group, a perylene group, a tetracenyl group, an anthracenyl group, and the like. The arylene group may be substituted or unsubstituted.

As used herein, the heteroarylene group contains 2 to 20 carbon atoms, 2 to 10 carbon atoms, or 6 to 20 carbon atoms. The heteroarylene group is an aryl group containing O, N, or S as a heteroatom, and the description of a heteroaryl group as defined above can be applied to it, except that it is a divalent functional group. The heteroarylene group may be substituted or unsubstituted.

или

означает связь, связанную с другой группой заместителя.In the present description, the symbol

or

means a bond associated with another substituent group.

In the present description, a direct connection or a simple connection means a connection with a linkage in which no atoms or atomic groups exist in the corresponding position.

1. Acid anhydride compound

According to one embodiment of the present invention, an acid anhydride compound having the structure represented by chemical formula 1 can be provided.

By experiment, the present inventors have found that since the silicon atom in the monomer structure forms a ring structure (a ring structure linked by L ₁ -X ₁ -S _i -X ₂ in the chemical formula 1) as in the acid anhydride compound of one embodiment , it can have high temperature resistance, and can suppress the charge transfer complex (CTC) of pi electrons present in the imide chain of the polyimide later synthesized by silicon, thus providing transparency, and due to the bonding property of silicon, birefringence can be controlled, greatly reducing slowdown. The present invention has been made based on these results.

Therefore, in the polyimide-based polymer, which is a combination product obtained by reacting an acid anhydride of one embodiment with a diamine compound, the cyclic structure of the silicon atom contained in the acid anhydride compound is maintained as it is, and thus the properties of the acid anhydride such as heat resistance, transparency and low retardation can be realized as they are.

In particular, in the chemical formula 1, X ₁ and X ₂ may be the same or different from each other, and each may independently represent a tetravalent organic group. More specifically, in the chemical formula 1, X ₁ and X ₂ are the same or different from each other, and each independently represents any of the tetravalent organic groups represented by the following chemical formula 2.

[Chemical formula 2]

In the chemical formula 2, R ₃ - R ₈ each independently represents hydrogen or an alkyl group containing 1-6 carbon atoms, and L ₂ is any value selected from the group consisting of a single bond, -O-, -CO-, -COO-, -S-, -SO-, -SO ₂ -, -CR ₉ R ₁₀ -, -(CH ₂ ) _t -, -O(CH ₂ ) _t O-, -COO(CH ₂ ) _t OCO -, -CONH-, phenylene, or combinations thereof, where, in L ₂ , R ₉ and R ₁₀ each independently represents any group selected from hydrogen or an alkyl group or haloalkyl group containing 1-10 carbon atoms, and t represents is an integer value from 1 to 10.

More specifically, in the chemical formula 1, X ₁ and X ₂ have the same meaning and may represent a functional group represented by the following chemical formula 2-1. Since the acid anhydride compound in one embodiment can suppress the formation of the charge transfer complex (CTC) of the pi electrons present in the imide chain of the polyimide, by means of the silicon contained in the monomer structure as described above, excellent transparency can be achieved without the introduction of a strong electron withdrawing group, such as trifluoromethyl (-CF ₃ ) group, as in the prior art.

[Chemical Formula 2-1]

Meanwhile, in the chemical formula 1, R ₁ and R ₂ are the same or different from each other, and each independently can be any of a substituted or unsubstituted alkyl group containing 1-20 carbon atoms, a substituted or unsubstituted alkoxy group containing 1-20 carbon atoms, a substituted or unsubstituted cycloalkyl group containing 3-20 carbon atoms, a substituted or unsubstituted aryl group containing 6-30 carbon atoms, or a substituted or unsubstituted heteroaryl group containing 3-30 carbon atoms.

As described above, the term "substituted or unsubstituted" means unsubstituted or substituted with one or more substituents selected from the group consisting of deuterium; halogen group; cyano group; nitro groups; hydroxy groups; carbonyl group; an ester group; imide group; amide group; primary amino group; carboxy groups; sulfonic acid groups; sulfonamide group; phosphine oxide group; alkoxy groups; aryloxy groups; alkylthio groups; arylthioxy groups; alkylsulfoxy groups; arylsulfoxy groups; silyl group; boron groups; an alkyl group; cycloalkyl group; alkenyl group; an aryl group; an aralkyl group; aralkenyl group; an alkylaryl group; alkoxysilylalkyl group; arylphosphine group; or a heterocyclic group containing at least one of N, O, and S atoms, or unsubstituted or substituted with a substituent to which two or more of the substituents exemplified above are attached.

In particular, in the chemical formula 1, R ₁ and R ₂ are the same or different from each other, and each independently can be any of a substituted or unsubstituted alkyl group containing 1 to 20 carbon atoms, or a substituted or unsubstituted aryl group containing 6 -30 carbon atoms.

More specifically, in the chemical formula 1, R ₁ and R ₂ have the same meaning, and each independently may be an unsubstituted alkyl group containing 1-20 carbon atoms or 1-10 carbon atoms. Examples of an unsubstituted alkyl group containing 1-20 carbon atoms or 1-10 carbon atoms include a methyl group.

In addition, in the chemical formula 1, R ₁ and R ₂ have the same meaning, and each independently can be an unsubstituted aryl group containing 6-30 carbon atoms, or 6-20 carbon atoms. Examples of an unsubstituted aryl group containing 6-30 carbon atoms or 6-20 carbon atoms include a phenyl group.

Moreover, in the chemical formula 1, L ₁ has any value selected from a simple bond, -O-, -CO-, -S-, -SO ₂ -, -C(CH ₃ ) ₂ -, -C(CF ₃ ) ₂ -, -CONH-, -COO-, -(CH ₂ ) _y -, -O(CH ₂ ) _y O-, -O(CH ₂ ) _y -, -NH-, -NH(CH ₂ ) _y -NH-, -NH(CH ₂ ) _y O-, -OCH ₂ -C(CH ₃ ) ₂ -CH ₂ O-, -COO-(CH ₂ ) _y -OCO-, or -OCO-(CH ₂ ) _y -COO- where, in L ₁ , y is an integer having a value from 1 to 10.

More specifically, in the chemical formula 1, L ₁ may be any of -O-, -S- or -SO ₂ -.

That is, the acid anhydride compound may include a compound represented by the following chemical formula 1-1 or a compound represented by the following chemical formula 1-2.

[Chemical formula 1-1]

[Chemical formula 1-2]

An acid anhydride compound in one embodiment can be reacted with a diamine compound to synthesize a polyamic acid or polyamic acid ester polymer as described below, and a polyimide can be synthesized by heat treatment of the polyamic acid or polyamic acid ester polymer. That is, the acid anhydride compound of another embodiment can be used to synthesize a polyimide-based polymer. Here, a polyimide-based polymer means including both a polyimide and a polyamic acid or polyamic acid ester as its precursor polymer.

2. Polyimide-based polymer

However, according to another embodiment of the present invention, it is possible to provide a polyimide-based polymer comprising at least one repeat unit selected from the group consisting of a repeat unit represented by the chemical formula 3, a repeat unit represented by the chemical formula 4, and a repeating unit represented by the chemical formula 5.

Polyimide-based polymer means including all of a polyimide and a polyamic acid or polyamic acid ester as a precursor polymer. That is, the polyimide-based polymer may include at least one selected from the group consisting of a polyamic acid repeat unit, a polyamic acid ester repeat unit, a polyimide repeat unit, and the like. That is, the polyimide-based polymer may include one kind of polyamic acid repeating unit, one kind of polyamic acid ester repeating unit, one kind of polyimide repeating unit, or a mixture of two or more repeating units of the above kinds.

In particular, the polyimide repeat unit may include the repeat unit represented by chemical formula 3, the polyamic acid ester repeat unit may include the repeat unit represented by chemical formula 4, and the polyamic acid repeat unit may include the repeat unit represented by chemical formula 5.

At least one repeat unit selected from the group consisting of a polyamic acid repeat unit, a polyamic acid ester repeat unit, and a polyimide repeat unit may form the backbone of the polyimide-based polymer.

The polyimide-based polymer may include a combined product of an acid anhydride compound of one embodiment and a diamine compound. The repeat unit represented by the chemical formula 3, the repeat unit represented by the chemical formula 4, and the repeat unit represented by the chemical formula 5 included in the polyimide-based polymer may be the repeat unit contained in the combined product obtained by reacting the compound of an acid anhydride of one embodiment and a diamine compound.

More specifically, a bond can be formed between the nitrogen atom of the amino group and the carbon atom of the anhydride group by reacting the anhydride end group (-OC-O-CO-) of the acid anhydride of one embodiment and the end amino group (-NH ₂ ) of the diamine compound.

Specific examples of the diamine compound may include at least one selected from the group consisting of 2,2'-bis(trifluoromethyl)-4,4'-biphenyldiamine, 2,2'-dimethyl-4,4'-diaminobenzidine, 4 ,4'-diaminodiphenylsulfone, 4,4'-(9-fluorenylidene)dianiline, bis(4-(4-aminophenoxy)phenyl)sulfone, 2,2',5,5'-tetrachlorobenzidine, 2,7-diaminofluorene, 4 ,4-diaminooctafluorobiphenyl, m-phenylenediamine, p-phenylenediamine, 4,4'-oxydianiline, 2,2'-dimethyl-4,4'-diaminobiphenyl, 2,2-bis[4-(4-aminophenoxy)phenyl]propane , 1,3-bis(4-aminophenoxy)benzene and 4,4'-diaminobenzanilide, or a mixture of two or more of them.

In particular, in the chemical formulas 3-5, X ₃ - X ₅ are the same or different from each other, and each independently can represent a functional group represented by the chemical formula 6. X ₃ - X ₅ are functional groups derived from an acid anhydride one embodiment, and in the functional group represented by the chemical formula 6, the definitions of X ₁ , X ₂ , R ₁ , R ₂ and L ₁ include all those described above in the chemical formula 1 of this one embodiment.

That is, in the polyimide-based polymer according to another embodiment, since X ₃ to X ₅ in the chemical formulas 3 to 5 include a tetravalent organic group represented by the chemical formula 6, the effect of the acid anhydride compound of one embodiment as such can be achieved and in particular, stable heat resistance and low retardation together with excellent transparency can be achieved.

More specifically, specific examples of the functional group represented by the chemical formula 6 include the functional group represented by the following chemical formula 6-1 or the functional group represented by the following chemical formula 6-2.

[Chemical Formula 6-1]

[Chemical formula 6-2]

In the chemical formula 4, at least one of R ₁₁ and R ₁₂ may be an alkyl group containing 1-10 carbon atoms, and the other may be hydrogen. That is, in the chemical formula 4, R ₁₁ may be an alkyl group containing 1 to 10 carbon atoms, and R ₁₂ may be hydrogen. In addition, in the chemical formula 4, R ₁₂ represents an alkyl group containing 1 to 10 carbon atoms, and R ₁₁ may represent hydrogen. In addition, in the chemical formula 4, R ₁₁ and R ₁₂ may represent an alkyl group containing 1-10 carbon atoms.

Meanwhile, in the chemical formulas 3-5, Y ₃ - Y ₅ may be any of the functional group represented by the following chemical formula 7 or the functional group represented by the following chemical formula 8. Y ₃ - Y ₅ may be a functional group, derived from a diamine compound used in the synthesis of polyamic acid, polyamic acid ester or polyimide.

[Chemical Formula 7]

In the chemical formula 7, R ₁₃ and R ₁₄ are each independently hydrogen, halogen, cyano, nitrile, alkyl having 1-10 carbon atoms, alkenyl having 1-10 carbon atoms, alkoxy having 1-10 carbon atoms, fluoroalkyl , containing 1-10 carbon atoms, or fluoroalkoxy containing 1-10 carbon atoms, p and q each independently represents an integer having a value from 0 to 4, L ₃ represents a single bond, -O-, -CO-, -S-, -SO ₂ -, -C(CH ₃ ) ₂ -, -C(CF ₃ ) ₂ -, -CONH-, -COO-, -(CH ₂ ) _y -, -O(CH ₂ ) _z O-, -O(CH ₂ ) _z -, -NH-, -NH(CH ₂ ) _z -NH-, -NH(CH ₂ ) _z O-, -OCH ₂ -C(CH ₃ ) ₂ -CH ₂ O-, -COO-(CH ₂ ) _z -OCO- or -OCO-(CH ₂ ) _z -COO-, z is an integer having a value from 1 to 10, k and m are each independently an integer, having a value from 0 to 3, and n is an integer having a value from 0 to 3.

[Chemical formula 8]

In the chemical formula 8, Ar ₁ and Ar ₂ are the same or different from each other, and each independently represents a substituted or unsubstituted alkylene group containing 1-20 carbon atoms, a substituted or unsubstituted cycloalkylene group containing 3-20 carbon atoms, substituted or an unsubstituted arylene group containing 6-30 carbon atoms, or a substituted or unsubstituted heteroarylene group containing 3-30 carbon atoms.

Specific examples of the functional group represented by the chemical formula 7 include 2,2'-bis(trifluoromethyl)-4,4'-biphenylene group represented by the following chemical formula 7-1, derived from 2,2'-bis(trifluoromethyl)-4 ,4'-biphenyldiamine.

[Chemical Formula 7-1]

In addition, examples of the functional group represented by the chemical formula 8 include the functional group represented by the following chemical formula 8-1 derived from 4,4'-(9-fluorenylidene)dianiline.

[Chemical Formula 8-1]

A polyimide-based polymer containing at least one selected from the group consisting of a repeating unit represented by the chemical formula 3, a repeating unit represented by the chemical formula 4, and a repeating unit represented by the chemical formula 5 can be obtained by reacting one kind of diamine compound together with an acid anhydride compound of one embodiment.

In particular, one kind of diamine compound that reacts with the acid anhydride compound of one embodiment may be any of the diamine compounds represented by the following chemical formula 9 or the diamine compounds represented by the following chemical formula 10.

[Chemical formula 9]

In the chemical formula 9, R ₁₃ and R ₁₄ each independently represents hydrogen, halogen, cyano, nitrile, alkyl containing 1-10 carbon atoms, alkenyl containing 1-10 carbon atoms, alkoxy containing 1-10 carbon atoms, fluoroalkyl , containing 1-10 carbon atoms, or fluoroalkoxy containing 1-10 carbon atoms, p and q each independently represents an integer having a value from 0 to 4, L ₃ represents a single bond, -O-, -CO-, -S-, -SO ₂ -, -C(CH ₃ ) ₂ -, -C(CF ₃ ) ₂ -, -CONH-, -COO-, -(CH ₂ ) _y -, -O(CH ₂ ) _z O-, -O(CH ₂ ) _z -, -NH-, -NH(CH ₂ ) _z -NH-, -NH(CH ₂ ) _z O-, -OCH ₂ -C(CH ₃ ) ₂ -CH ₂ O-, -COO-(CH ₂ ) _z -OCO- or -OCO-(CH ₂ ) _z -COO-, z is an integer having a value from 1 to 10, k and m are each independently an integer, having a value from 0 to 3, and n is an integer having a value from 0 to 3.

[Chemical Formula 10]

In the chemical formula 10, Ar ₁ and Ar ₂ are the same or different from each other, and each independently represents a substituted or unsubstituted alkylene group containing 1-20 carbon atoms, a substituted or unsubstituted cycloalkylene group containing 3-20 carbon atoms, substituted or an unsubstituted arylene group containing 6-30 carbon atoms, or a substituted or unsubstituted heteroarylene group containing 3-30 carbon atoms.

Meanwhile, the polyimide-based polymer may include: a first repeating unit selected from the group consisting of a repeating unit represented by the following chemical formula 3-1, a repeating unit represented by the following chemical formula 4-1, and a repeating unit represented by the following chemical formula 5-1; and a second repeat unit selected from the group consisting of a repeat unit represented by the following chemical formula 3-2, a repeat unit represented by the following chemical formula 4-2, and a repeat unit represented by the following chemical formula 5-2.

[Chemical Formula 3-1]

[Chemical formula 4-1]

[Chemical formula 5-1]

In the chemical formulas 3-1-5-1, at least one of R ₂₁ and R ₂₂ is an alkyl group containing 1-10 carbon atoms and the other is hydrogen, X ₆ - X ₈ are the same or different from each other and each independently represents a functional group represented by the chemical formula 6, and Y ₆ to Y ₈ are the same or different from each other, and each independently represents a functional group represented by the chemical formula 7.

[Chemical Formula 3-2]

[Chemical formula 4-2]

[Chemical Formula 5-2]

In chemical formulas 3-2-5-2

at least one of R ₂₃ and R ₂₄ is an alkyl group containing 1-10 carbon atoms and the other is hydrogen, X ₉ - X ₁₁ are the same or different from each other and each independently represents a functional group represented by a chemical formula 6, and Y ₉ - Y ₁₁ are the same or different from each other and each independently represents a functional group represented by the chemical formula 8.

That is, the polyimide-based polymer may include: a first repeat unit containing a functional group represented by the chemical formula 7 as a diamine-derived repeat unit; and a second repeat unit containing the functional group represented by the chemical formula 8 as a diamine-derived repeat unit. The first repeat unit and the second repeat unit may be randomly located in the polyimide polymer to form a random copolymer, or may form a block of the first repeat unit and a block of the second repeat units to form a block copolymer.

A polyimide-based polymer comprising a first repeating unit selected from the group consisting of a repeating unit represented by the chemical formula 3-1, a repeating unit represented by the chemical formula 4-1, and a repeating unit represented by the chemical formula 5-1, and a second repeating unit a unit selected from the group consisting of a repeating unit represented by the chemical formula 3-2, a repeating unit represented by the chemical formula 4-2, and a repeating unit represented by the chemical formula 5-2 can be obtained by reacting two different diamine compounds together with the compound an acid anhydride of one embodiment, and two kinds of diamine compounds can be added simultaneously to synthesize a random copolymer, or added sequentially to synthesize a block copolymer.

In particular, two different diamine compounds that are reacted together with an acid anhydride compound of one embodiment may be a diamine compound represented by the chemical formula 9 and a diamine compound represented by the chemical formula 10.

The weight average molecular weight (measured by GPC) of the polyimide-based polymer is not particularly limited, but may be, for example, 10,000 g/mol to 200,000 g/mol.

The polyimide-based polymer of the present invention can exhibit excellent characteristics such as colorlessness and transparency while maintaining characteristics such as heat resistance, mechanical strength, and the like due to its rigid structure. Therefore, it can be used in various fields such as device substrate, display cover substrate, optical film, integrated circuit (IC) package, adhesive film, multi-layer flexible printed circuit (FPC), adhesive tape, touch panel, protective film for an optical disc and the like, and in particular, it may be suitable for a substrate for covering a display.

Examples of the method for synthesizing a polyimide-based polymer are not particularly limited, but, for example, an arbitrary diamine compound commonly used to produce a polyamic acid can be reacted with an acid anhydride compound of another embodiment to obtain a polymer comprising an amino acid, an amino acid ester, or their mixture.

Alternatively, if necessary, one or more additional diamine compounds or one or more acid anhydride compounds may be mixed to form a polyamic acid copolymer, a polyamic acid ester copolymer, and a polyimide copolymer. In addition, another polyimide-based polymer is polymerized using one or more additional diamine compounds or one or more acid anhydride compounds, and then mixed with the polyimide-based polymer of another embodiment to obtain a polyamic acid polymer blend, a polyamic acid ester polymer blend and a polyimide resin. polymer mixture.

The reaction conditions can be appropriately adjusted in accordance with the conditions for the production of polyamic acids, which are known in the technical field to which the present invention relates, such as solution polymerization. In particular, the production method may include dissolving the diamine in an organic solvent and then adding an acid anhydride compound to carry out a polymerization reaction. The reaction can be carried out under an inert gas or nitrogen atmosphere, and it can also be carried out under anhydrous conditions. In addition, the polymerization reaction can be carried out at -20 to 60°C or 0 to 30°C.

In addition, the organic solvent that can be used for the polymerization may be specifically selected from the group consisting of ketones such as γ-butyrolactone, 1,3-dimethyl-imidazolidinone, methyl ethyl ketone, cyclohexanone, cyclopentanone, 4-hydroxy- 4-methyl-2-pentanone and the like; aromatic hydrocarbons such as toluene, xylene, tetramethylbenzene and the like; glycol ethers (cellosolve), such as 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 monomethyl ether, propylene glycol monoethyl ether, dipropylene glycol diethyl ether, triethylene glycol monoethyl ether and t. P.; 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, dimethylacetamide (DMAc), N,N-diethylacetamide, dimethylformamide (DMF) ), diethylformamide (DEF), N-methylpyrrolidone (NMP), N-ethylpyrrolidone (NEP), 1,3-dimethyl-2-imidazolidinone, 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-methoxyethoxy)ethane, bis[2-(2-methoxyethoxy)]ether and mixtures thereof.

Meanwhile, the amino acid, amino acid ester, or mixture thereof obtained above can be imidized to obtain a polyimide-based polymer comprising at least one repeating unit selected from the group consisting of a repeating unit represented by the chemical formula 3, a repeating a unit represented by the chemical formula 4 and a repeating unit represented by the chemical formula 5.

In particular, the imidization process may be a chemical imidization or thermal imidization method. For example, a polyamide can be obtained by adding a dehydrating agent and an imidization catalyst to a solution of a polymerized polyamic acid or a polyamic acid ester, and then heating it to a temperature of 50 to 100°C for imidization through a chemical reaction or refluxing the solution to remove the alcohol for imidization .

In the chemical imidization process, the imidization catalyst may be pyridine, triethylamine, picoline, or quinoline, as well as a substituted or unsubstituted nitrogen-containing heterocyclic compound, an N-oxide compound of a nitrogen-containing heterocyclic compound, a substituted or unsubstituted amino acid compound, or an aromatic hydrocarbon compound, or an aromatic heterocyclic compound. a compound containing a hydroxyl group. In particular, it may be a lower alkylimidazole such as 1,2-dimethylimidazole, N-methylimidazole, N-benzyl-2-methylimidazole, 2-methylimidazole, 2-ethyl-4-methylimidazole, 5-methylbenzimidazole and the like; an imidazole derivative such as N-benzyl-2-methylimidazole and the like; substituted pyridine such as isoquinoline, 3,5-dimethylpyridine, 3,4-dimethylpyridine, 2,5-dimethylpyridine, 2,4-dimethylpyridine, 4-n-propylpyridine and the like, or p-toluenesulfonic acid, etc. P. The dehydrating agent may be an acid anhydride such as acetic anhydride.

Alternatively, the imidization can be carried out by applying a solution of a polyamic acid or a polyamic acid ester to a substrate, followed by heating in an oven or hot plate at a temperature of 100 to 300°C, and the heating can be carried out in a multi-stage process at various temperatures within the indicated temperature range.

3. Polymer film

At the same time, according to another embodiment of the present invention, a resin film including a cured polyimide-based polymer product of another embodiment can be provided. A cured polyimide-based polymer product means a substance obtained during the curing of a polyimide-based polymer. Details regarding the polyimide-based polymer may include everything described above in other embodiments.

As described above, when a polyimide-based polymer containing at least one selected from the group consisting of a polyamic acid repeat unit, a polyamic acid ester repeat unit, and a polyimide repeat unit is used, a polymer film capable of providing stable properties can be obtained. heat resistance together with excellent transparency.

The thickness of the resin film is not particularly limited, but can be freely adjusted in the range of, for example, 0.01 to 1000 µm. When the thickness of the polymer film is increased or decreased by a certain amount, the physical properties defined by the polymer film may also change by a certain amount.

Examples of the resin film synthesis method are not particularly limited, but, for example, a resin film production method including the steps of applying a polymer resin composition containing a polyimide-based polymer according to another embodiment to a substrate to form a film coating (step 1); drying the film coating (stage 2); and heat treating and curing the dried film coating (step 3).

Step 1 is a step of applying the polymer resin composition containing the polyimide-based polymer described above to a substrate to form a coating film. The method for applying the polymer resin composition containing the polyimide-based polymer to the substrate is not particularly limited, but for example, methods such as screen printing, offset printing, flexographic printing, inkjet printing, and the like can be used.

Further, the polymer resin composition containing the polyimide-based polymer may be in a form dissolved or dispersed in an organic solvent. In the case of these forms, for example, when the polyimide polymer is synthesized in an organic solvent, the solution itself may be the reaction solution to be obtained, or the reaction solution may be diluted with another solvent. In addition, when the polyimide-based polymer is obtained as a powder, it can be dissolved in an organic solvent to form a solution.

Specific examples of the organic solvent include N,N-dimethylformamide, N,N-dimethylacetamide, N-methyl-2-pyrrolidone, N-methylcaprolactam, 2-pyrrolidone, N-ethylpyrrolidone, N-vinylpyrrolidone, dimethylsulfoxide, tetramethylurea, pyridine, dimethylsulfone, hexamethylsulfoxide , γ-butyrolactone, 3-methoxy-N,N-dimethylpropanamide, 3-ethoxy-N,N-dimethylpropanamide, 3-butoxy-N,N-dimethylpropanamide, 1,3-dimethylimidazolidinone, ethylamyl ketone, methyl nonyl ketone, methyl ethyl ketone, methyl isoamyl ketone, methyl isopropyl ketone , cyclohexanone, ethylene carbonate, propylene carbonate, diglyme, 4-hydroxy-4-methyl-2-pentanone, ethylene glycol monomethyl ether, ethylene glycol monomethyl ether acetate, ethylene glycol monoethyl ether, ethylene glycol monoethyl ether acetate, ethylene glycol monopropyl ether, ethylene glycol monopropyl ether acetate, monoisopropyl ether ethylene glycol, ethylene glycol monoisopropyl ether acetate, ethylene glycol monobutyl ether, ethylene glycol monobutyl ether acetate, and the like. They can be used alone or as a combination of two or more of them.

The polymer resin composition may have a solids content such that the polymer resin composition has a suitable viscosity in view of processing characteristics such as film-forming coating capability. For example, the content in the composition can be adjusted so that the total polymer content is from 5 to 30 wt%.

In addition, the resin composition can be adjusted to have a viscosity of 500 cps or more, 1000 cps or more, or 2000 cps or more, and the viscosity of the resin composition can be 30,000 cps or less, 20,000 cps or less, 18,000 cps or more. less, or 15,000 cps or less. When the viscosity of the polymer resin composition is less than 500 cps or more than 30,000 cps, bubble formation and surface roughness may adversely affect film processing, and optical performance may deteriorate.

In addition, the polymer resin composition may further include other components in addition to the organic solvent. In a non-limiting example, when the polymer resin composition is applied as a coating, additives can be further included that can improve film thickness uniformity and surface smoothness, improve adhesion between the polymer resin composition and the substrate, change the dielectric constant and conductivity of the polymer resin composition, or increase the density of the polymer composition. resins. Examples of such additives include various kinds of solvents, surfactants, silane compounds, dielectrics, crosslinkers, and the like.

Step 2 is a drying step of the coating film formed by applying the resin composition to the substrate.

The drying step of the film coating may be carried out with a heating means such as a hot plate, a hot air circulation oven, an infrared oven or the like, and the drying may be carried out at a temperature of 50°C to 150°C or 50 to 100°C. WITH.

Stage 3 is the stage of heat treatment and curing of the dried film coating. Meanwhile, the heat treatment can be carried out using a heating means such as a hot plate, a hot air circulation oven, an infrared oven, and the like, and the heat treatment can be carried out at a temperature of 180°C to 500°C or 200°C to 500°C.

The use of the resin film is not particularly limited, and it can be used as a retardation optical film, for example.

4. Optical device

At the same time, according to another embodiment of the present invention, an optical device including a resin film of another embodiment can be provided. Details regarding the polymeric film may include all the details described above in other embodiments.

The optical device may include various devices using properties realized by light, and may include, for example, a display device. Specific examples of the display device include, but are not limited to, a liquid crystal display (LCD), an organic light emitting diode (OLED) device, a flexible display, and a rollable or folding display.

The optical device may have different structures depending on the application and the specific form. For example, it may be a structure including a plastic cover window, a touch panel, a polarizer, a barrier film, a light emitting element (OLED element, etc.), a transparent substrate, or the like.

The polymer film of another embodiment described above can be used in various applications such as a substrate, an outer protective film, or a cover window in such various optical devices, and more specifically, it can be applied to a substrate.

For example, the display device substrate may have a structure in which a device protective layer, a transparent electrode layer, a silicon oxide layer, a polyimide film, a silicon oxide layer, and a hard coating layer are successively laminated, and another embodiment resin film may be incorporated into the device substrate polyimide film. display.

The display device substrate may include a silicon oxide layer formed between the transparent polyimide film and the cured layer in order to further improve solvent resistance or water permeability and optical properties, and the silicon oxide layer may be formed by curing the polysilazane.

In particular, the silicon oxide layer can be formed, before forming the coating layer on at least one side of the transparent polyimide film, by applying and drying a solution containing polysilazane, and then curing the applied polysilazane layer.

Beneficial effects

According to the present invention, it is possible to provide a method for producing an acid anhydride compound capable of realizing stable heat resistance properties together with excellent transparency, a polyimide-based polymer, a polymer film, and an optical device for which they are used.

Detailed description of embodiments

Hereinafter, the present invention will be described in more detail using examples. However, these examples are presented for illustrative purposes only and are not intended to limit the scope of the present invention.

<Synthesis Example>

Synthesis Example 1 Preparation of Acid Anhydride Compound DA-1

The acid anhydride compound DA-1 having the structure shown above was obtained by the following method. The specific mechanism for the synthesis of the acid anhydride compound DA-1 is as follows.

The results of FT-IR and ¹ H NMR measurements of acid anhydride (DA-1) are as follows.

Fourier transform infrared spectroscopy:

¹ H NMR (DMF-d7):

Synthesis Example 2: Preparation of Acid Anhydride Compound DA-2

The acid anhydride compound DA-2 having the structure shown above was prepared in the same manner as in Synthesis Example 1, except that diphenyldichlorosilane was used instead of dimethyldichlorosilane. The specific mechanism for the synthesis of DA-2 acid anhydride is as follows.

The results of ¹ H NMR measurements of acid anhydride (DA-2) are as follows.

¹ H NMR (DMF-d7):

<Examples: Preparation of polyamic acid solution and polyimide film>

Example 1

(1) Preparation of polyamic acid solution

2,2'-bis(trifluoromethyl)-4,4'-biphenyldiamine (TFMB) was completely dissolved in anhydrous N-methylpyrrolidone (NMP). Then, the acid anhydride compound DA-1 obtained in Synthesis Example 1 was added to the ice bath solution so that the molar ratio of TFMB:DA-1=50:50 was satisfied, and the mixture was stirred at room temperature for about 16 hours to effect synthesis of polyamic acid polymer P-1.

The P-1 polyamic acid polymer thus obtained was placed in a mixed solvent consisting of NMP and n-butoxyethanol and stirred at 25° C. for 16 hours. The resulting solution was filtered under pressure through a 0.1 μm filter made of poly(tetrafluoroethylene) to obtain a polyamic acid solution.

(2) Production of polyimide film

The polyamic acid solution obtained in (1) of Example 1 was spin-coated to a thickness of 0.1 µm on a 2.5 cm × 2.7 cm square glass substrate. Then, the polyamic acid solution coated substrate was placed on a hot plate at 80 °C and dried for 30 minutes. Then, the film was heat-treated (cured) in an oven at 400° C. for 40 minutes to obtain a polyimide film.

Example 2

The polyamic acid polymer P-2, the polyamic acid solution, and the polyimide film were obtained in the same manner as in Example 1, except that the acid anhydride compound DA-2 obtained in Synthesis Example 2 was used in the process for preparing the polyamic acid solution, instead of the compound acid anhydride DA-1 obtained in Synthesis Example 1, thus the molar ratio of TFMB:DA-2=50:50 was satisfied.

Example 3

Polyamic acid polymer P-3, polyamic acid solution, and polyimide film were prepared in the same manner as in Example 1, except that 4,4'-(9-fluorenylidene)dianiline (BAFL) was used in the process for preparing the polyamic acid solution. 2,2'-bis(trifluoromethyl)-4,4'-biphenyldiamine (TFMB), thus a molar ratio of BAFL:DA-1=50:50 was satisfied.

Example 4

Polyamic acid polymer P-4, polyamic acid solution, and polyimide film were prepared in the same manner as in Example 2, except that 4,4'-(9-fluorenylidene)dianiline (BAFL) was used in the process for preparing the polyamic acid solution. 2,2'-bis(trifluoromethyl)-4,4'-biphenyldiamine (TFMB), thus a molar ratio of BAFL:DA-2=50:50 was satisfied.

Example 5

Polyamic acid polymer P-5, polyamic acid solution and polyimide film were obtained in the same manner as in Example 1, except that a mixture of 2,2'-bis(trifluoromethyl)-4,4' was used in the process of preparing the polyamic acid solution. -biphenyldiamine (TFMB) and 4,4'-(9-fluorenylidene)dianiline (BAFL) instead of 2,2'-bis(trifluoromethyl)-4,4'-biphenyldiamine (TFMB), thus the molar ratio (TFMB+BAFL ):DA-1=50:50 was satisfied.

Example 6

Polyamic acid polymer P-6, polyamic acid solution and polyimide film were obtained in the same manner as in Example 2, except that a mixture of 2,2'-bis(trifluoromethyl)-4,4' was used in the process of preparing the polyamic acid solution. -biphenyldiamine (TFMB) and 4,4'-(9-fluorenylidene)dianiline (BAFL) instead of 2,2'-bis(trifluoromethyl)-4,4'-biphenyldiamine (TFMB), thus the molar ratio (TFMB+BAFL ):DA-2=50:50 was satisfied.

[Experimental examples]

The following properties of the polyamic acid solution or polyimide film obtained in the examples above were measured or evaluated, and the results are shown in Table 1 below.

Experimental Example 1: Viscosity

With regard to the polyamic acid solution prepared in the examples, the relative viscosity was measured using a Brookfield DV-2T viscometer with an LV-4 spindle (64) at 0.3-100 rpm in accordance with ASTM D 2196 "Method for testing the rheological properties of non-Newtonian materials with using a rotational viscometer, using an isothermal reflux system of 25 ± 0.2°C, where a number of standard solutions with a viscosity range from 5,000 to 100,000 cps were used as Brookfield silicon and oil viscosity standards. The unit used was cps.

Experimental Example 2: Thickness

With regard to the polyimide film obtained in the examples, the film thickness was determined using TENCOR Alpha-Step.

Experimental Example 3: Yellowness Index (Y.I.)

With regard to the polyimide film obtained in the examples, the yellowness index (YI) was measured using a differential colorimeter (Color Eye 7000A).

Experiment 4: Passing

With regard to the polyimide films obtained in the examples, the average transmittance (T) of light at a wavelength of 380 to 780 nm was measured using a UV-visible spectroscopy system (Agilent, UV 8453).

Experiment 5: Deceleration (Rth) in Thickness Direction at 550 nm

A sample having a length of 76 mm, a width of 52 mm, and a thickness of 13 μm was obtained from the polyimide films obtained in the examples, and "AxoScan" from AXOMETRICS was used as a measuring device. The retardation (Rth) in the thickness direction was determined as follows: the value of the refractive index (the refractive index of the film for light at 550 nm, obtained by measuring the refractive index described above) is entered, then the retardation in the thickness direction is measured using light at a wavelength of 550 nm in temperature conditions: 25°C and humidity: 40%; and using the measured retardation value in the thickness direction thus determined (value determined by automatic measurement using the measuring device).

Experimental Example 6: Coefficient of Thermal Expansion (CTE) and Glass Transition Temperature

For the polyimide films prepared in the examples, 5 x 20 mm samples were prepared using TMA (TA Instruments, Q400). The samples were then loaded with an accessory and the actual measured film length was set to 16 mm. The pulling force of the film was set to 0.02 N, the measurement start temperature was raised to 350°C at a rate of 5°C/min from 100°C, and the linear thermal expansion coefficient was measured at the first cooling. Then, heating to 350° C. was carried out, a tangent was drawn at the segment where the inclination angle began to increase in the second heating, and the starting point where the inclination angle began to increase was measured by setting the Tg interval.

Experimental Example 7 Thermal Decomposition Temperature 1% (Td 1%)

With regard to the polyimide films obtained in the examples, the thermal decomposition temperature was measured in accordance with the ISO 11359 test method.

Experimental Example 8: Mechanical Properties (Modulus of Elasticity, Maximum Tensile Strength, Maximum Elongation)

With regard to the polyimide films obtained in the examples, the film was cut into a width of 5 mm or more and a length of 60 mm or more using Zwick UTM, and then the gap between the grippers was set to 40 mm, and the measured value was confirmed by drawing the sample at a speed of 10 mm/min.

The results of Experimental Examples 1-8 are shown in Table 1 below.

Table 1 Example 1 Example 2 Molar ratio of monomers TFMB:DA-1=50:50 TFMB:DA-2=50:50 Solid content (% wt.) 7.5 27.46 Viscosity(cps) 2138 3507 Thickness(µm) 9.43 11.71 Y.I. 5.2 6.3 T (%)@380nm ~ 780nm 87.5 86.9 Deceleration in thickness direction (Rth, nm) 500 300 Thermal expansion coefficient (ppm) 17.6 14.3 Glass transition temperature (°C) N/D
(Not determined) N/D
(Not determined) Thermal decomposition temperature 1% (°C) 511 523 Modulus of elasticity (GPa) 5.4 6.3 Maximum tensile strength (MPa) 227.2 250 Max elongation (%) 14.9 13.3

As shown in Table 1, it was confirmed that the polyimide films obtained in Examples 1 and 2 exhibit a low yellowness index (YI) and high transparency to visible light, and thus excellent optical transparency, and that the measured retardation value is low, and low retardation was achieved in accordance with birefringence control. In addition, the above polyimide film was confirmed to have a low thermal expansion coefficient, a high glass transition temperature, and a high thermal decomposition temperature, and exhibit a good level of mechanical physical properties while showing excellent heat resistance performance.

Claims (43)

1. A polyimide-based polymer for producing a polymer film, comprising at least one repeating unit selected from the group consisting of a repeating unit represented by the following chemical formula 3, a repeating unit represented by the following chemical formula 4, and a repeating unit represented by the following chemical formula formula 5:

, where, in chemical formulas 3-5, at least one of R ₁₁ and R ₁₂ is an alkyl group containing 1-10 carbon atoms and the other is hydrogen, X ₃ - X ₅ are the same or different from each other, and each independently represents a functional group represented by the following chemical formula 6, and Y ₃ - Y ₅ are the same or different from each other and each independently represents a divalent organic group, [Chemical formula 6]

where, in chemical formula 6, X ₁ and X ₂ are the same and each is a group

, R ₁ and R ₂ are the same and are each independently any of an unsubstituted alkyl group containing 1-20 carbon atoms or an unsubstituted aryl group, and L ₁ is -O-, wherein Y ₃ - Y ₅ is a functional group represented by the following chemical formula 7-1: [Chemical Formula 7-1]

. 2. The polyimide-based polymer of claim 1, wherein the polyimide-based polymer comprises: a first repeat unit selected from the group consisting of a repeat unit represented by the following chemical formula 3-1, a repeat unit represented by the following chemical formula 4-1, and a repeat unit represented by the following chemical formula 5-1; And a second repeat unit selected from the group consisting of a repeat unit represented by the following chemical formula 3-2, a repeat unit represented by the following chemical formula 4-2, and a repeat unit represented by the following chemical formula 5-2:

, where, in the chemical formulas 3-1-5-1, at least one of R ₂₁ and R ₂₂ is an alkyl group containing 1-10 carbon atoms and the other is hydrogen, X ₆ - X ₈ are the same or different from each other and each independently represents a functional group represented by the chemical formula 6, and Y ₆ - Y ₈ are the same or different from each other and each independently represents a functional group represented by the chemical formula 7-1:

where, in chemical formula 6, X ₁ and X ₂ are the same and each is a group

, R ₁ and R ₂ are the same and are each independently any of an unsubstituted alkyl group containing 1-20 carbon atoms or an unsubstituted aryl group L ₁ is -O-:

, where, in the chemical formulas 3-2-5-2, at least one of R ₂₃ and R ₂₄ is an alkyl group containing 1-10 carbon atoms and the other is hydrogen, X ₉ - X ₁₁ are the same or different from each other and each independently represents a functional group represented by the chemical formula 6, and Y ₉ - Y ₁₁ are the same or different from each other, and each independently represents a functional group represented by the chemical formula 8-1:

. 3. A polymer film for the manufacture of an optical device, including a cured polymer product based on polyimide according to claim 1. 4. An optical device including a polymer film according to claim 3.