(19)
(11)EP 3 467 042 B1

(12)EUROPEAN PATENT SPECIFICATION

(45)Mention of the grant of the patent:
25.03.2020 Bulletin 2020/13

(21)Application number: 17884529.3

(22)Date of filing:  29.11.2017
(51)International Patent Classification (IPC): 
C08L 79/08(2006.01)
C08J 5/18(2006.01)
C08G 73/10(2006.01)
(86)International application number:
PCT/KR2017/013831
(87)International publication number:
WO 2018/117465 (28.06.2018 Gazette  2018/26)

(54)

POLYAMIDE-IMIDE COPOLYMER AND COLORLESS AND TRANSPARENT POLYAMIDE-IMIDE FILM INCLUDING SAME

POLYAMID-IMID-COPOLYMER UND FARBLOSER UND TRANSPARENTER POLYAMID-IMID-FILM DAMIT

COPOLYMÈRE DE POLYAMIDE-IMIDE ET FILM DE POLYAMIDE-IMIDE INCOLORE ET TRANSPARENT COMPRENANT CELUI-CI


(84)Designated Contracting States:
AL AT BE BG CH CY CZ DE DK EE ES FI FR GB GR HR HU IE IS IT LI LT LU LV MC MK MT NL NO PL PT RO RS SE SI SK SM TR

(30)Priority: 20.12.2016 KR 20160174936
28.11.2017 KR 20170160632

(43)Date of publication of application:
10.04.2019 Bulletin 2019/15

(73)Proprietor: LG Chem, Ltd.
Seoul 07336 (KR)

(72)Inventors:
  • RYU, Bi Oh
    Daejeon 34122 (KR)
  • PAEK, Kwan Yeol
    Daejeon 34122 (KR)
  • TAE, Young Ji
    Daejeon 34122 (KR)
  • PARK, Soon Yong
    Daejeon 34122 (KR)
  • PARK, Young Seok
    Daejeon 34122 (KR)

(74)Representative: Goddar, Heinz J. 
Boehmert & Boehmert Anwaltspartnerschaft mbB Pettenkoferstrasse 22
80336 München
80336 München (DE)


(56)References cited: : 
EP-A1- 2 540 760
WO-A1-2012/144563
KR-A- 20130 029 129
KR-A- 20150 077 177
EP-A2- 0 125 599
JP-A- 2006 176 746
KR-A- 20130 071 650
  
      
    Note: Within nine months from the publication of the mention of the grant of the European patent, any person may give notice to the European Patent Office of opposition to the European patent granted. Notice of opposition shall be filed in a written reasoned statement. It shall not be deemed to have been filed until the opposition fee has been paid. (Art. 99(1) European Patent Convention).


    Description

    [TECHNICAL FIELD]



    [0001] The present disclosure relates to a polyamideimide copolymer and a colorless and transparent polyamideimide film including the same.

    [BACKGROUND OF ART]



    [0002] An aromatic polyimide resin is a polymer mostly having an amorphous structure, and exhibits excellent heat resistance, chemical resistance, electrical properties, and dimensional stability due to its rigid chain structure. The polyimide resin is widely used as an electric/electronic material.

    [0003] However, the polyimide resin has many limitations in use, because it is dark brown due to the formation of a CTC (charge transfer complex) of π electrons present in the imide chain.

    [0004] In order to solve the limitations and obtain a colorless transparent polyimide resin, a method of restricting the movement of the π electrons by introducing a strong electron attracting group such as a trifluoromethyl (-CF3) group, a method of reducing the formation of the CTC by introducing a sulfone (-SO2-) group, an ether (-O-) group, or the like into the main chain to make a bent structure, or a method of inhibiting the formation of the resonance structure of the π electrons by introducing an aliphatic cyclic compound, has been proposed.

    [0005] However, it is difficult for the polyimide resin according to the proposals to exhibit sufficient heat resistance due to the bending structure or the aliphatic cyclic compound, and a film prepared using the same still has limitations such as poor mechanical properties.

    [0006] On the other hand, in recent years, polyamideimide copolymers having a polyamide unit structure to improve the scratch resistance of polyimide have been developed.

    [0007] However, the polyamideimide copolymer tends to easily produce haze when a film is formed by coating the same due to its high crystallinity.

    [0008] Such a haze characteristic of the polyamideimide film is severely manifested and affects the yellow index (YI) as the thickness of the film is thicker, so a method for improving them is required.

    [DETAILED DESCRIPTION OF THE INVENTION]


    [Technical Problem]



    [0009] The present disclosure is to provide a polyamideimide copolymer exhibiting excellent scratch resistance while being colorless and transparent.

    [0010] In addition, the present disclosure is to provide a colorless and transparent polyamideimide film including the polyamideimide copolymer.

    [Technical Solution]



    [0011] The present disclosure provides a polyamideimide copolymer, which is an imide of a polyamic acid resulting from copolymerizing an aromatic diamine monomer, an aromatic dianhydride monomer, and an aromatic dicarbonyl monomer,
    wherein the aromatic dicarbonyl monomer is contained in an amount of at least 60 mol% based on the total moles of the aromatic dianhydride monomer and the aromatic dicarbonyl monomer, and
    the aromatic dicarbonyl monomer consists of 10 to 40 mol% of isophthaloyl chloride and 60 to 90 mol% of terephthaloyl chloride.

    [0012] In addition, the present disclosure provides a polyamideimide film including the polyamideimide copolymer.

    [0013] Hereinafter, the polyamideimide copolymer and the polyamideimide film according to the exemplary embodiments of the present disclosure will be described in more detail.

    [0014] In this specification, terms are used merely to refer to specific embodiments, and are not intended to restrict the present disclosure unless this is explicitly expressed.

    [0015] Singular expressions of the present disclosure may include plural expressions unless it is differently expressed contextually.

    [0016] The terms "include", "comprise", and the like of the present disclosure are used to specify certain features, regions, integers, steps, operations, elements, and/or components, and these do not exclude the existence or the addition of other certain features, regions, integers, steps, operations, elements, and/or components.

    I. Polyamideimide copolymer



    [0017] One embodiment of the present disclosure provides a polyamideimide copolymer, which is an imide of a polyamic acid resulting from copolymerizing an aromatic diamine monomer, an aromatic dianhydride monomer and an aromatic dicarbonyl monomer,
    wherein the aromatic dicarbonyl monomer is contained in an amount of at least 60 mol% based on the total moles of the aromatic dianhydride monomer and the aromatic dicarbonyl monomer, and
    the aromatic dicarbonyl monomer consists of 10 to 40 mol% of isophthaloyl chloride and 60 to 90 mol% of terephthaloyl chloride.

    [0018] As a result of further studies by the present inventors, it was confirmed that a copolymer having excellent scratch resistance while being colorless and transparent can be formed, when aromatic dicarbonyl monomers having a specific composition are used to form a polyamideimide copolymer using an aromatic diamine monomer, an aromatic dianhydride monomer, and an aromatic dicarbonyl monomer.

    [0019] That is, the aromatic dicarbonyl monomer of the specified composition according to the embodiment of the present disclosure can minimize crystallization during copolymerization with aromatic diamine monomers and aromatic dianhydride monomers, enabling the formation of a polyamideimide copolymer exhibiting excellent scratch resistance together with low haze.

    [0020] According to the embodiment of the present disclosure, the polyamideimide copolymer is an imide of a polyamic acid resulting from copolymerizing an aromatic diamine monomer, an aromatic dianhydride monomer, and an aromatic dicarbonyl monomer.

    [0021] The polyamic acid may be a block copolymer or a random copolymer.

    [0022] For example, the polyamic acid block copolymer may have a first unit structure derived from the copolymerization of the aromatic diamine monomer and the aromatic dianhydride monomer, and a second unit structure derived from copolymerization of the aromatic diamine monomer and the aromatic dicarbonyl monomer.

    [0023] In the polyamic acid random copolymer, the polyamideimide copolymer may have a unit structure in which the aromatic diamine monomer, the aromatic dianhydride monomer, and the aromatic dicarbonyl monomer each form an amide bond and are randomly copolymerized.

    [0024] This polyamic acid forms a polyamideimide copolymer having an imide bond and an amide bond simultaneously by imidization.

    [0025] According to an embodiment of the present disclosure, the aromatic dicarbonyl monomer is preferably contained in an amount of at least 60 mol% based on the total moles of the aromatic dianhydride monomer and the aromatic dicarbonyl monomer, in order to form a copolymer exhibiting excellent scratch resistance while being colorless and transparent.

    [0026] Preferably, the aromatic dicarbonyl monomer may be contained in an amount of 60 mol% or more, 65 mol% or more, or 67 mol% or more based on the total moles of the aromatic dianhydride monomer and the aromatic dicarbonyl monomer.

    [0027] However, when the aromatic dicarbonyl monomer is used in an excessive amount, problems such as lowered moisture absorbency or opacity may occur. Therefore, it is preferable that the aromatic dicarbonyl monomer is contained in an amount of 90 mol% or less, 85 mol% or less, or 80 mol% or less based on the total moles of the aromatic dianhydride monomer and the aromatic dicarbonyl monomer.

    [0028] In particular, according to an embodiment of the present disclosure, it is preferable that the aromatic dicarbonyl monomer includes isophthaloyl chloride and terephthaloyl chloride together.

    [0029] The isophthaloyl chloride and terephthaloyl chloride are compounds in which two carbonyl groups are bonded at the meta or para position with respect to the central phenylene group.

    [0030] Therefore, it is possible to exhibit an advantageous effect for improving the processability due to the meta bond in the copolymer and for improving the mechanical properties due to the para bond, by applying isophthaloyl chloride together with terephthaloyl chloride as the aromatic dicarbonyl monomer to form a polyamideimide copolymer.

    [0031] Further, according to an embodiment of the present disclosure, the aromatic dicarbonyl monomer preferably consists of 10 to 40 mol% of isophthaloyl chloride and 60 to 90 mol% of terephthaloyl chloride.

    [0032] That is, the isophthaloyl chloride and terephthaloyl chloride included in the aromatic dicarbonyl monomer can improve the processability and mechanical properties of the copolymer in the above-mentioned molar ratio, and at the same time, exhibit high hardness and low haze.

    [0033] Preferably, the isophthaloyl chloride is contained in an amount of 10 mol% or more, or 12 mol% or more, and 40 mol% or less, 35 mol% or less, or 30 mol% or less based on the total moles of the aromatic dicarbonyl monomer. Preferably, the terephthaloyl chloride is contained in an amount of 90 mol% or less, or 88 mol% or less, and 60 mol% or more, 65 mol% or more, or 70 mol% or more based on the total moles of the aromatic dicarbonyl monomer.

    [0034] As described above, the polyamideimide copolymer according to the embodiment of the present disclosure may exhibit excellent scratch resistance (high grade pencil hardness) and a colorless transparent characteristic (low haze and yellow index), only when the composition of the aromatic dicarbonyl monomer satisfies both of the following two conditions.
    1. (i) The aromatic dicarbonyl monomer should be contained in an amount of at least 60 mol% based on the total moles of the aromatic dianhydride monomer and the aromatic dicarbonyl monomer.
    2. (ii) The aromatic dicarbonyl monomer should consist of 10 to 40 mol% of isophthaloyl chloride and 60 to 90 mol% of terephthaloyl chloride.


    [0035] According to an embodiment of the present disclosure, as the aromatic diamine monomer and the aromatic dianhydride monomer for forming the polyamideimide copolymer, compounds commonly used in the technical field to which the present invention pertains may be applied without particular limitation.

    [0036] Specifically, the aromatic diamine monomer may preferably be at least one compound selected from the group consisting of 2,2'-bis(trifluoromethyl)-4,4'-biphenyldiamine, 4,4'-diaminodiphenyl sulfone, 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.

    [0037] More preferably, the aromatic diamine monomer may be 2,2'-bis(trifluoromethyl)-4,4'-biphenyldiamine.

    [0038] The aromatic dianhydride monomer may preferably be at least one compound selected from the group consisting of 3,3',4,4'-biphenyltetracarboxylic dianhydride, 4,4'-(hexafluoroisopropylidene)diphthalic anhydride, 2,2'-bis-(3,4-dicarboxyphenyl)hexafluoropropane dianhydride, benzophenone tetracarboxylic dianhydride, pyromellitic dianhydride, benzophenone tetracarboxylic dianhydride, oxydiphthalic anhydride, cyclobutane-1,2,3,4-tetracarboxylic dianhydride, cyclopentane tetracarboxylic dianhydride, and bis(3,4-dicarboxyphenyl)sulfone dianhydride.

    [0039] More preferably, the aromatic dianhydride monomer may be cyclobutane-1,2,3,4-tetracarboxylic dianhydride, 3,3',4,4'-biphenyltetracarboxylic acid dianhydride, or a mixture of the same.

    [0040] Particularly, the aromatic diamine monomer, 2,2'-bis(trifluoromethyl)-4,4'-biphenyldiamine, and an aromatic dianhydride monomer, 3,3',4,4'-biphenyltetracarboxylic acid dianhydride, can be advantageously used for the formation of the polyamideimide copolymer satisfying the above-mentioned characteristics by copolymerizing with the above aromatic dicarbonyl monomer consisting of isophthaloyl chloride and terephthaloyl chloride.

    [0041] Preferably, the aromatic dicarbonyl monomer is contained in an amount of 30 mol% or more, 35 mol% or more, or 40 mol% or more, and 55 mol% or less, 50 mol% or less, or 45 mol% or less based on the total moles of the aromatic diamine monomer and the aromatic dicarbonyl monomer.

    [0042] Further, the polymerization conditions for forming the polyamic acid resulting from copolymerizing the aromatic diamine monomer, the aromatic dianhydride monomer, and the aromatic dicarbonyl monomer are not particularly limited.

    [0043] Preferably, the polymerization for forming the polyamic acid may be carried out by solution polymerization under an inert atmosphere at 0 to 100 °C.

    [0044] In the formation of the polyamic acid, a solvent such as N,N-dimethylformamide, dimethylacetamide, dimethyl sulfoxide, acetone, N-methyl-2-pyrrolidone, tetrahydrofuran, chloroform, gamma-butyrolactone, or the like may be used.

    [0045] Imidization after the formation of the polyamic acid may be carried out thermally or chemically. For example, compounds such as acetic anhydride, pyridine, and the like may be used for chemical imidization.

    [0046] According to the embodiment of the present disclosure, the polyamideimide copolymer may have a weight average molecular weight of 10,000 to 1,000,000 g/mol, 50,000 to 1,000,000 g/mol, 50,000 to 500,000 g/mol, or 50,000 to 300,000 g/mol.

    II. Polyamideimide film



    [0047] According to another embodiment of the present disclosure, a colorless and transparent polyamideimide film including the polyamideimide copolymer is provided.

    [0048] As described above, as a result of further studies by the present inventors, it was confirmed that a copolymer having excellent scratch resistance while being colorless and transparent can be formed, when aromatic dicarbonyl monomers having a specific composition are used to form a polyamideimide copolymer using an aromatic diamine monomer, an aromatic dianhydride monomer, and an aromatic dicarbonyl monomer.

    [0049] As a result, the film including the polyamideimide copolymer can be suitably used as a base material for various molded articles requiring colorless transparency as well as excellent scratch resistance. For example, such a polyamideimide film can be applied for substrates for displays, protective films for displays, touch panels, and the like.

    [0050] The polyamideimide film may be prepared by a conventional method such as a dry method or a wet method using the polyamideimide copolymer. For example, the polyamideimide film may be obtained by coating a solution containing the copolymer on an arbitrary support to form a film, and drying the film by evaporating the solvent from the film. If necessary, stretching and heat treatment for the polyamideimide film may be carried out.

    [0051] The polyamideimide film may exhibit excellent scratch resistance while being colorless and transparent, because it is prepared using the polyamideimide copolymer.

    [0052] Specifically, the polyamideimide film may exhibit pencil hardness of at least a 2H grade or at least a 3H grade as measured in accordance with ASTM D3363 with respect to a specimen having a thickness of 30 ± 2 µm.

    [0053] In addition, the polyamideimide film may have a yellow index (YI) of 3.0 or less, 2.8 or less, 2.75 or less, 2.5 to 2.75, 2.6 to 2.75, or 2.65 to 2.75, as measured in accordance with ASTM D1925 with respect to a specimen having a thickness of 30 ± 2 µm.

    [0054] In addition, the polyamideimide film may have haze of 0.5 % or less, 0.4 % or less, 0.1 to 0.5 %, 0.2 to 0.5 %, or 0.2 to 0.4 %, as measured in accordance with ASTM D1003 with respect to a specimen having a thickness of 30 ± 2 µm.

    [0055] In addition, the polyamideimide film may have transmittance of 88.5 % or more, 89 % or more, or 88.5 to 89 % with respect to visible light having a wavelength of 550 nm in a thickness of 30 ± 5 µm.

    [0056] In addition, the polyamideimide film may exhibit transmittance of 25 % or less, 15 % or less, 13 % or less, 10 to 25 %, or 11 to 25 % with respect to ultraviolet light having a wavelength of 388 nm in a thickness of 30 ± 2 µm.

    [ADVANTAGEOUS EFFECTS]



    [0057] The polyamideimide copolymer according to the present disclosure makes it possible to provide a polyamideimide film exhibiting excellent scratch resistance while being colorless and transparent.

    [DETAILED DESCRIPTION OF THE EMBODIMENTS]



    [0058] Hereinafter, preferred examples are provided for better understanding. However, these examples are for illustrative purposes only, and the invention is not intended to be limited by these examples.

    Example 1



    [0059] In a 1000 mL reactor equipped with a stirrer, a nitrogen injector, a dropping funnel, and a temperature controller, 42.5 g of dimethylacetamide was placed while slowly flowing nitrogen therein, the temperature of the reactor was adjusted to 25 °C, and 4.4354 g (0.0138507 mol) of 2,2'-bis(trifluoromethyl)-4,4'-biphenyldiamine was added thereto to be completely dissolved. While maintaining the temperature of the solution at 25 °C, 0.815 g (0.0027701 mol) of 3,3',4,4'-biphenyltetracarboxylic acid dianhydride was added thereto to be dissolved.

    [0060] After the temperature of the solution was cooled down to -10 °C, 0.2812 g (0.0013851 mol) of isophthaloyl chloride and 1.9684 g (0.0096955 mol) of terephthaloyl chloride were added thereto and stirred to obtain a polyamic acid solution having a solid content of 15 wt%.

    [0061] Dimethylacetamide was added to the polyamic acid solution to dilute the solid content to 5 wt% or less, and then the solid content was precipitated using 10 L of methanol.

    [0062] The precipitated solid content was filtered and then dried at 100 °C under vacuum for 6 hours or more to obtain a polyamideimide copolymer in the form of a solid (weight average molecular weight: about 188,517 g/mol).

    Example 2



    [0063] In a 1000 mL reactor equipped with a stirrer, a nitrogen injector, a dropping funnel, and a temperature controller, 42.5 g of dimethylacetamide was placed while slowly flowing nitrogen therein, the temperature of the reactor was adjusted to 25 °C, and 4.3448 g (0.0135539 mol) of 2,2'-bis(trifluoromethyl)-4,4'-biphenyldiamine was added thereto to be completely dissolved. While maintaining the temperature of the solution at 25 °C, 1.316 g (0.0044728 mol) of 3,3',4,4'-biphenyltetracarboxylic acid dianhydride was added thereto to be dissolved.

    [0064] After the temperature of the solution was cooled down to -10 °C, 0.3302 g (0.0016265 mol) of isophthaloyl chloride and 1.5134 g (0.0074546 mol) of terephthaloyl chloride were added thereto and stirred to obtain a polyamic acid solution having a solid content of 15 wt%.

    [0065] Dimethylacetamide was added to the polyamic acid solution to dilute the solid content to 5 wt% or less, and then the solid content was precipitated using 10 L of methanol.

    [0066] The precipitated solid content was filtered and then dried at 100 °C under vacuum for 6 hours or more to obtain a polyamideimide copolymer in the form of a solid (weight average molecular weight: about 88,320 g/mol).

    Example 3



    [0067] In a 1000 mL reactor equipped with a stirrer, a nitrogen injector, a dropping funnel, and a temperature controller, 42.5 g of dimethylacetamide was placed while slowly flowing nitrogen therein, the temperature of the reactor was adjusted to 25 °C, and 4.2714 g (0.0133386 mol) of 2,2'-bis(trifluoromethyl)-4,4'-biphenyldiamine was added thereto to be completely dissolved. While maintaining the temperature of the solution at 25 °C, 1.2951 g (0.0044017 mol) of 3,3',4,4'-biphenyltetracarboxylic acid dianhydride was added thereto to be dissolved.

    [0068] After the temperature of the solution was cooled down to -10 °C, 0.5524 g (0.0027211 mol) of isophthaloyl chloride and 1.3811 g (0.0068027 mol) of terephthaloyl chloride were added thereto and stirred to obtain a polyamic acid solution having a solid content of 15 wt%.

    [0069] Dimethylacetamide was added to the polyamic acid solution to dilute the solid content to 5 wt% or less, and then the solid content was precipitated using 10 L of methanol.

    [0070] The precipitated solid content was filtered and then dried at 100 °C under vacuum for 6 hours or more to obtain a polyamideimide copolymer in the form of a solid (weight average molecular weight: about 78,880 g/mol).

    Comparative Example 1



    [0071] In a 1000 mL reactor equipped with a stirrer, a nitrogen injector, a dropping funnel, and a temperature controller, 42.5 g of dimethylacetamide was placed while slowly flowing nitrogen therein, the temperature of the reactor was adjusted to 25 °C, and 4.3619 g (0.0136213 mol) of 2,2'-bis(trifluoromethyl)-4,4'-biphenyldiamine was added thereto to be completely dissolved. While maintaining the temperature of the solution at 25 °C, 1.2023 g (0.0040864 mol) of 3,3',4,4'-biphenyltetracarboxylic acid dianhydride was added thereto to be dissolved.

    [0072] After the temperature of the solution was cooled down to -10 °C, 1.9358 g (0.0095349 mol) of terephthaloyl chloride was added thereto and stirred to obtain a polyamic acid solution having a solid content of 15 wt%.

    [0073] Dimethylacetamide was added to the polyamic acid solution to dilute the solid content to 5 wt% or less, and then the solid content was precipitated using 10 L of methanol.

    [0074] The precipitated solid content was filtered and then dried at 100 °C under vacuum for 6 hours or more to obtain a polyamideimide copolymer in the form of a solid (weight average molecular weight: about 151,440 g/mol).

    Comparative Example 2



    [0075] In a 1000 mL reactor equipped with a stirrer, a nitrogen injector, a dropping funnel, and a temperature controller, 42.5 g of dimethylacetamide was placed while slowly flowing nitrogen therein, the temperature of the reactor was adjusted to 25 °C, and 4.59 g (0.0143335 mol) of 2,2'-bis(trifluoromethyl)-4,4'-biphenyldiamine was added thereto to be completely dissolved.

    [0076] After the temperature of the solution was cooled down to -10 °C, 1.455 g (0.0071667 mol) of isophthaloyl chloride and 1.455 g (0.0071667 mol) of terephthaloyl chloride were added thereto and stirred to obtain a polymer solution having a solid content of 15 wt%.

    [0077] Dimethylacetamide was added to the polymer solution to dilute the solid content to 5 wt% or less, and then the solid content was precipitated using 10 L of methanol.

    [0078] The precipitated solid content was filtered and then dried at 100 °C under vacuum for 6 hours or more to obtain a copolymer in the form of a solid (weight average molecular weight: about 70,174 g/mol).

    Comparative Example 3



    [0079] In a 1000 mL reactor equipped with a stirrer, a nitrogen injector, a dropping funnel, and a temperature controller, 42.5 g of dimethylacetamide was placed while slowly flowing nitrogen therein, the temperature of the reactor was adjusted to 25 °C, and 4.1789 g (0.0130496 mol) of 2,2'-bis(trifluoromethyl)-4,4'-biphenyldiamine was added thereto to be completely dissolved.

    [0080] While maintaining the temperature of the solution at 25 °C, 1.1518 g (0.0039149 mol) of 3,3',4,4'-biphenyltetracarboxylic acid dianhydride and 0.5797 g (0.001304956 mol) of 4,4'-(hexafluoroisopropylidene)diphthalic anhydride were added thereto to be dissolved.

    [0081] After the temperature of the solution was cooled down to -10 °C, 1.5896 g (0.0078297 mol) of terephthaloyl chloride was added thereto and stirred to obtain a polyamic acid solution having a solid content of 15 wt%.

    [0082] Dimethylacetamide was added to the polyamic acid solution to dilute the solid content to 5 wt% or less, and then the solid content was precipitated using 10 L of methanol.

    [0083] The precipitated solid content was filtered and then dried at 100 °C under vacuum for 6 hours or more to obtain a polyamideimide copolymer in the form of a solid (weight average molecular weight: about 84,224 g/mol).

    Comparative Example 4



    [0084] In a 1000 mL reactor equipped with a stirrer, a nitrogen injector, a dropping funnel, and a temperature controller, 42.5 g of dimethylacetamide was placed while slowly flowing nitrogen therein, the temperature of the reactor was adjusted to 25 °C, and 4.0105 g (0.0125239 mol) of 2,2'-bis(trifluoromethyl)-4,4'-biphenyldiamine was added thereto to be completely dissolved.

    [0085] While maintaining the temperature of the solution at 25 °C, 1.1054 g (0.0037572 mol) of 3,3',4,4'-biphenyltetracarboxylic acid dianhydride and 1.1127 g (0.0025048 mol) of 4,4'-(Hexafluoroisopropylidene)diphthalic anhydride were added thereto to be dissolved.

    [0086] After the temperature of the solution was cooled down to -10 °C, 1.2713 g (0.006262 mol) of terephthaloyl chloride was added thereto and stirred to obtain a polyamic acid solution having a solid content of 15 wt%.

    [0087] Dimethylacetamide was added to the polyamic acid solution to dilute the solid content to 5 wt% or less, and then the solid content was precipitated using 10 L of methanol.

    [0088] The precipitated solid content was filtered and then dried at 100 °C under vacuum for 6 hours or more to obtain a polyamideimide copolymer in the form of a solid (weight average molecular weight: about 79,427 g/mol).

    Comparative Example 5



    [0089] In a 1000 mL reactor equipped with a stirrer, a nitrogen injector, a dropping funnel, and a temperature controller, 42.5 g of dimethylacetamide was placed while slowly flowing nitrogen therein, the temperature of the reactor was adjusted to 25 °C, and 4.2221 g (0.0131845 mol) of 2,2'-bis(trifluoromethyl)-4,4'-biphenyldiamine was added thereto to be completely dissolved. While maintaining the temperature of the solution at 25 °C, 1.9396 g (0.0065922 mol) of 3,3',4,4'-biphenyltetracarboxylic acid dianhydride was added thereto to be dissolved.

    [0090] After the temperature of the solution was cooled down to -10 °C, 0.2677 g (0.0013184 mol) of isophthaloyl chloride and 1.0707 g (0.0052738 mol) of terephthaloyl chloride were added thereto and stirred to obtain a polyamic acid solution having a solid content of 15 wt%.

    [0091] Dimethylacetamide was added to the polyamic acid solution to dilute the solid content to 5 wt% or less, and then the solid content was precipitated using 10 L of methanol.

    [0092] The precipitated solid content was filtered and then dried at 100 °C under vacuum for 6 hours or more to obtain a polyamideimide copolymer in the form of a solid (weight average molecular weight: about 98,411 g/mol).

    Comparative Example 6



    [0093] In a 1000 mL reactor equipped with a stirrer, a nitrogen injector, a dropping funnel, and a temperature controller, 42.5 g of dimethylacetamide was placed while slowly flowing nitrogen therein, the temperature of the reactor was adjusted to 25 °C, and 4.2221 g (0.0131845 mol) of 2,2'-bis(trifluoromethyl)-4,4'-biphenyldiamine was added thereto to be completely dissolved. While maintaining the temperature of the solution at 25 °C, 1.9396 g (0.0065922 mol) of 3,3',4,4'-biphenyltetracarboxylic acid dianhydride was added thereto to be dissolved.

    [0094] After the temperature of the solution was cooled down to -10 °C, 0.5353 g (0.0026369 mol) of isophthaloyl chloride and 0.803 g (0.0039553 mol) of terephthaloyl chloride were added thereto and stirred to obtain a polyamic acid solution having a solid content of 15 wt%.

    [0095] Dimethylacetamide was added to the polyamic acid solution to dilute the solid content to 5 wt% or less, and then the solid content was precipitated using 10 L of methanol.

    [0096] The precipitated solid content was filtered and then dried at 100 °C under vacuum for 6 hours or more to obtain a polyamideimide copolymer in the form of a solid (weight average molecular weight: about 87,887 g/mol).

    Comparative Example 7



    [0097] In a 1000 mL reactor equipped with a stirrer, a nitrogen injector, a dropping funnel, and a temperature controller, 42.5 g of dimethylacetamide was placed while slowly flowing nitrogen therein, the temperature of the reactor was adjusted to 25 °C, and 4.3619 g (0.01362 mol) of 2,2'-bis(trifluoromethyl)-4,4'-biphenyldiamine was added thereto to be completely dissolved. While maintaining the temperature of the solution at 25 °C, 1.2023 g (0.004086 mol) of 3,3',4,4'-biphenyltetracarboxylic acid dianhydride was added thereto to be dissolved.

    [0098] After the temperature of the solution was cooled down to -10 °C, 0.9679 g (0.004767 mol) of isophthaloyl chloride and 0.9679 g (0.004767 mol) of terephthaloyl chloride were added thereto and stirred to obtain a polyamic acid solution having a solid content of 15 wt%.

    [0099] Dimethylacetamide was added to the polyamic acid solution to dilute the solid content to 5 wt% or less, and then the solid content was precipitated using 10 L of methanol.

    [0100] The precipitated solid content was filtered and then dried at 100 °C under vacuum for 6 hours or more to obtain a polyamideimide copolymer in the form of a solid (weight average molecular weight: about 87,156 g/mol).

    Comparative Example 8



    [0101] In a 1000 mL reactor equipped with a stirrer, a nitrogen injector, a dropping funnel, and a temperature controller, 42.5 g of dimethylacetamide was placed while slowly flowing nitrogen therein, the temperature of the reactor was adjusted to 25 °C, and 3.9676 g (0.01239 mol) of 2,2'-bis(trifluoromethyl)-4,4'-biphenyldiamine was added thereto to be completely dissolved. While maintaining the temperature of the solution at 25 °C, 3.2808 g (0.01115 mol) of 3,3',4,4'-biphenyltetracarboxylic acid dianhydride was added thereto to be dissolved.

    [0102] After the temperature of the solution was cooled down to -10 °C, 0.1258 g (0.00062 mol) of isophthaloyl chloride and 0.1258 g (0.00062 mol) of terephthaloyl chloride were added thereto and stirred to obtain a polyamic acid solution having a solid content of 15 wt%.

    [0103] Dimethylacetamide was added to the polyamic acid solution to dilute the solid content to 5 wt% or less, and then the solid content was precipitated using 10 L of methanol.

    [0104] The precipitated solid content was filtered and then dried at 100 °C under vacuum for 6 hours or more to obtain a polyamideimide copolymer in the form of a solid (weight average molecular weight: about 94,117 g/mol).
    [Table 1]
    mol%TFDBBPDA6FDAIPCTPC
    Example 1 50.00 10.00 - 5.00 35.00
    Example 2 50.00 16.50 - 6.00 27.50
    Example 3 48.92 16.14 - 9.98 24.95
    [Table 2]
    mol %TFDBBPDA6FDAIPCTPC
    Comparative Example 1 50.00 15.00 - - 35.00
    Comparative Example 2 50.00 - - 25.00 25.00
    Comparative Example 3 50.00 15.00 5.00 - 30.00
    Comparative Example 4 50.00 15.00 10.00 - 25.00
    Comparative Example 5 50.00 25.00 - 5.00 20.00
    Comparative Example 6 50.00 25.00 - 10.00 15.00
    Comparative Example 7 50.00 15.00 - 17.50 17.50
    Comparative Example 8 50.00 45.00 - 2.50 2.50
    *TFDB: 2,2'-Bis(trifluoromethyl)-4,4'-biphenyldiamine
    *BPDA: 3,3',4,4'-Biphenyltetracarboxylic acid dianhydride
    *6FDA: 4,4'-(Hexafluoroisopropylidene)diphthalic anhydride
    *IPC: Isophthaloyl chloride
    *TPC: Terephthaloyl chloride

    Example 4



    [0105] The copolymer obtained in the Example 1 was dissolved in dimethylacetamide to prepare a polymer solution of about 25 % (w/V). The polymer solution was poured onto a plastic substrate (UPILEX-75s, UBE) and the thickness of the polymer solution was uniformly controlled using a film applicator, dried in a Mathis oven at 80 °C for 10 minutes, and then cured at 250 °C for 30 minutes while flowing nitrogen therein to obtain a polyamideimide film having a thickness of 30 µm peeled from the substrate.

    Example 5



    [0106] A film was obtained in the same manner as in Example 4, except that the copolymer obtained in Example 2 was used in place of the copolymer obtained in Example 1.

    Example 6



    [0107] A film was obtained in the same manner as in Example 4, except that the copolymer obtained in Example 3 was used in place of the copolymer obtained in Example 1.

    Comparative Example 9



    [0108] A film was obtained in the same manner as in Example 4, except that the copolymer obtained in Comparative Example 1 was used in place of the copolymer obtained in Example 1.

    Comparative Example 10



    [0109] A film was obtained in the same manner as in Example 4, except that the copolymer obtained in Comparative Example 2 was used in place of the copolymer obtained in Example 1.

    Comparative Example 11



    [0110] A film was obtained in the same manner as in Example 4, except that the copolymer obtained in Comparative Example 3 was used in place of the copolymer obtained in Example 1.

    Comparative Example 12



    [0111] A film was obtained in the same manner as in Example 4, except that the copolymer obtained in Comparative Example 4 was used in place of the copolymer obtained in Example 1.

    Comparative Example 13



    [0112] A film was obtained in the same manner as in Example 4, except that the copolymer obtained in Comparative Example 5 was used in place of the copolymer obtained in Example 1.

    Comparative Example 14



    [0113] A film was obtained in the same manner as in Example 4, except that the copolymer obtained in Comparative Example 6 was used in place of the copolymer obtained in Example 1.

    Comparative Example 15



    [0114] A film was obtained in the same manner as in Example 4, except that the copolymer obtained in Comparative Example 7 was used in place of the copolymer obtained in Example 1.

    Comparative Example 16



    [0115] A film was obtained in the same manner as in Example 4, except that the copolymer obtained in Comparative Example 8 was used in place of the copolymer obtained in Example 1.

    Experimental Examples



    [0116] The following characteristics were measured for the films of the Examples 4 to 6 and Comparative Examples 9 to 16, and the results are shown in Tables 3 and 4 below.

    (1) Pencil hardness



    [0117] The pencil hardness of the films was measured in accordance with ASTM D3363 using a Pencil Hardness Tester. Specifically, pencils of varying hardness values were fixed to the tester and scratched on the film, and the degree of occurrence of scratches on the film was observed with the naked eye or with a microscope. When more than 70 % of the total number of scratches were not observed, a value corresponding to the hardness of the pencil was evaluated as the pencil hardness of the film.

    (2) Yellow Index (YI)



    [0118] The yellow index (YI) of the film was measured according to the method of ASTM D1925 using a COH-400 Spectrophotometer (NIPPON DENSHOKU INDUSTRIES).

    (3) Transmittance (T)



    [0119] The total light transmittance of the film was measured using a UV-VIS-NIR Spectrophotometer (SolidSpec-3700, SHIMADZU), and the transmittance with respect to visible light having a wavelength of 550 nm and the transmittance with respect to ultraviolet light having a wavelength of 388 nm are shown in Table 3.

    (4) Haze



    [0120] The haze of the film was measured according to the method of ASTM D1003 using a COH-400 Spectrophotometer (NIPPON DENSHOKU INDUSTRIES).
    [Table 3]
     Pencil hardnessYIT (%) @550 nmT (%) @388 nmHaze (%)
    Example 4 3H 2.65 88.7 25.0 0.4
    Example 5 3H 2.67 89.4 11.4 0.3
    Example 6 3H 2.74 89.0 12.8 0.2
    [Table 4]
     Pencil hardnessYIT (%) @550 nmT (%) @388 nmHaze (%)
    Comparative Example 9 3H 3.43 88.1 10.4 1.2
    Comparative Example 10 6B 2.08 89.1 34.8 0.2
    Comparative Example 11 H 2.67 88.2 13.2 0.7
    Comparative Example 12 F 2.59 88.8 15.8 0.6
    Comparative Example 13 HB 5.21 88.0 4.8 0.8
    Comparative Example 14 B 4.81 88.1 8.8 0.7
    Comparative Example 15 3B 4.11 88.7 11.1 0.4
    Comparative Example 16 B 5.28 87.9 2.1 1.0


    [0121] Referring to Tables 3 and 4, it was confirmed that all the films of Examples 4 to 6 exhibited a high pencil hardness of a 3H grade and a low yellow index (YI) of 3.0 or less.

    [0122] Although the films of Comparative Examples 9 and 11 included a copolymer in which the aromatic dicarbonyl monomer was contained in an amount of 60 mol% or more based on the total moles of the aromatic dianhydride monomer and the aromatic dicarbonyl monomer, it was found that they exhibited a higher yellow index, higher haze, or lower pencil hardness than the films of the examples, because the copolymer included only terephthaloyl chloride as the aromatic dicarbonyl monomer.

    [0123] In addition, although the films of Comparative Examples 13 and 16 included a copolymer to which isophthaloyl chloride and terephthaloyl chloride were applied as the aromatic dicarbonyl monomer, it was found that they exhibited a higher yellow index, higher haze, or lower pencil hardness than the films of the examples, because the composition of the aromatic dicarbonyl monomer did not satisfy the composition according to the embodiment of the present disclosure.


    Claims

    1. A polyamideimide copolymer, which is an imide of a polyamic acid resulting from copolymerizing an aromatic diamine monomer, an aromatic dianhydride monomer, and an aromatic dicarbonyl monomer,
    wherein the aromatic dicarbonyl monomer is contained in an amount of at least 60 mol% based on the total moles of the aromatic dianhydride monomer and the aromatic dicarbonyl monomer, and
    the aromatic dicarbonyl monomer consists of 10 to 40 mol% of isophthaloyl chloride and 60 to 90 mol% of terephthaloyl chloride.
     
    2. The polyamideimide copolymer of Claim 1,
    wherein the aromatic diamine monomer is at least one compound selected from the group consisting of 2,2'-bis(trifluoromethyl)-4,4'-biphenyldiamine, 4,4'-diaminodiphenyl sulfone, 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.
     
    3. The polyamideimide copolymer of Claim 1,
    wherein the aromatic dianhydride monomer is at least one compound selected from the group consisting of 3,3',4,4'-biphenyltetracarboxylic dianhydride, 4,4'-(hexafluoroisopropylidene)diphthalic anhydride, 2,2'-bis-(3,4-dicarboxyphenyl)hexafluoropropane dianhydride, benzophenone tetracarboxylic dianhydride, pyromellitic dianhydride, benzophenone tetracarboxylic dianhydride, oxydiphthalic anhydride, cyclobutane-1,2,3,4-tetracarboxylic dianhydride, cyclopentane tetracarboxylic dianhydride, and bis(3,4-dicarboxyphenyl)sulfone dianhydride.
     
    4. A polyamideimide film comprising the polyamideimide copolymer of Claim 1.
     
    5. The polyamideimide film of Claim 4,
    wherein the film has pencil hardness of a 2H grade or more as measured according to ASTM D3363 with respect to a specimen having a thickness of 30 ± 2 µmof, and
    a yellow index (YI) of 3.0 or less as measured according to ASTM D1925.
     
    6. The polyamideimide film of Claim 4,
    wherein the film has haze of 0.5 % or less as measured according to ASTM D1003 with respect to a specimen having a thickness of 30 ± 2 µm,
    transmittance of 88.5 % or more with respect to visible light having a wavelength of 550 nm, and
    transmittance of 25 % or less with respect to ultraviolet light having a wavelength of 388 nm.
     
    7. The polyamideimide copolymer of Claim 1,
    wherein the aromatic dicarbonyl monomer is contained in an amount of 30 mol% to 55 mol% based on the total moles of the aromatic diamine monomer and the aromatic dicarbonyl monomer.
     


    Ansprüche

    1. Polyamidimidcopolymer, welches ein Imid einer Polyamidsäure, resultierend aus einer Copolymerisation eines aromatischen Diaminmonomers, eines aromatischen Dianhydridmonomers und eines aromatischen Dicarbonylmonomers, ist,
    wobei das aromatische Dicarbonylmonomer in einer Menge von wenigstens 60 mol% enthalten ist, basierend auf den gesamten Molen des aromatischen Dianhydridmonomers und des aromatischen Dicarbonylmonomers, und
    das aromatische Dicarbonylmonomer aus 10 bis 40 mol% Isophthaloylchlorid und 60 bis 90 mol% Terephthaloylchlorid besteht.
     
    2. Polyamidimidcopolymer nach Anspruch 1,
    wobei das aromatische Diaminmonomer wenigstens eine Verbindung ist, ausgewählt aus der Gruppe bestehend aus 2,2'-Bis(trifluormethyl)-4,4'-biphenyldiamin, 4,4'-Diaminodiphenylsulfon, 4,4'-(9-Fluorenyliden)dianilin, Bis(4-(4-aminophenoxy)phenyl)sulfon, 2,2',5,5'-Tetrachlorbenzidin, 2,7-Diaminofluoren, 4,4-Diaminooctafluorbiphenyl, m-Phenylendiamin, p-Phenylendiamin, 4,4'-Oxydianilin, 2,2'-Dimethyl-4,4'-diaminobiphenyl, 2,2-Bis[4-(4-aminophenoxy)phenyl]propan, 1,3-bis(4-Aminophenoxy)benzol und 4,4'-Diaminobenzanilid.
     
    3. Polyamidimidcopolymer nach Anspruch 1,
    wobei das aromatische Dianhydridmonomer wenigstens eine Verbindung ist, ausgewählt aus der Gruppe bestehend aus 3,3',4,4'-Biphenyltetracarbonsäuredianhydrid, 4,4'-(Hexafluorisopropyliden)diphthal-säureanhydrid, 2,2'-Bis-(3,4-dicarboxyphenyl)hexafluorpropandianhydrid, Benzophenontetracarbonsäuredianhydrid, Pyromellithsäuredianhydrid, Benzophenontetracarbonsäuredianhydrid, Oxydiphthalsäureanhydrid, Cyclobutan-1,2,3,4-tetracarbonsäuredianhydrid, Cyclopentantetracarbonsäuredianhydrid und Bis(3,4-dicarboxyphenyl)sulfondianhydrid.
     
    4. Polyamidimidfilm, umfassend das Polyamidimidcopolymer nach Anspruch 1.
     
    5. Polyamidimidfilm nach Anspruch 4,
    wobei der Film eine Bleistifthärte von einer 2H-Stufe oder mehr, gemessen gemäß ASTM D3363 in Bezug auf einen Probenkörper mit einer Dicke von 30 ± 2 µm, und
    einen Vergilbungsindex (YI) von 3,0 oder weniger, wie gemessen gemäß ASTM D1925, aufweist.
     
    6. Polyamidimidfilm nach Anspruch 4,
    wobei der Film eine Trübung von 0,5% oder weniger, wie gemessen gemäß ASTM D1003 in Bezug auf einen Probenkörper mit einer Dicke von 30 ± 2 µm,
    einer Lichtdurchlässigkeit von 88,5% oder mehr in Bezug auf sichtbares Licht mit einer Wellenlänge von 550 nm, und
    eine Lichtdurchlässigkeit von 25% oder weniger in Bezug auf ultraviolettes Licht mit einer Wellenlänge von 388 nm aufweist.
     
    7. Polyamidimidcopolymer nach Anspruch 1,
    wobei das aromatische Dicarbonylmonomer in einer Menge von 30 mol% bis 55 mol% enthalten ist, basierend auf den gesamten Molen des aromatischen Diaminmonomers und des aromatischen Dicarbonylmonomers.
     


    Revendications

    1. Copolymère poly(amide-imide), qui est un imide d'un acide polyamique résultant de la copolymérisation d'un monomère diamine aromatique, d'un monomère dianhydride aromatique et d'un monomère dicarbonyle aromatique,
    où le monomère dicarbonyle aromatique est contenu à une quantité, rapportée aux moles totales de monomère dianhydride aromatique et de monomère dicarbonyle aromatique, qui est de 60 % en moles au moins et
    le monomère dicarbonyle aromatique consiste en de 10 à 40 % en moles de chlorure d'isophtaloyle et de 60 à 90 % en moles de chlorure de téréphtaloyle.
     
    2. Copolymère poly(amide-imide) de la revendication 1,
    où le monomère diamine aromatique est un au moins composé sélectionné dans le groupe consistant en les suivants : 2,2'-bis(trifluorométhyl)-4,4'-biphényldiamine, 4,4'-diaminodiphénylsulfone, 4,4'-(9-fluorénylidène)dianiline, bis(4-(4-aminophénoxy)phényl)sulfone, 2,2',5,5'-tétrachlorobenzidine, 2,7-diaminofluorène, 4,4-diaminooctafluorobiphényle, m-phénylènediamine, p-phénylènediamine, 4,4'-oxydianiline, 2,2'-diméthyl-4,4'-diaminobiphényle, 2,2-bis[4-(4-aminophénoxy)phényl]propane, 1,3-bis(4-aminophénoxy)benzène et 4,4'-diaminobenzanilide.
     
    3. Copolymère poly(amide-imide) de la revendication 1,
    où le monomère dianhydride aromatique est un au moins composé sélectionné dans le groupe consistant en les suivants : dianhydride 3,3',4,4'-biphényltétracarboxylique, anhydride 4,4'-(hexafluoroisopropylidène)diphtalique, dianhydride de 2,2'-bis-(3,4-dicarboxyphényl)hexafluoropropane, dianhydride de benzophénone tétracarboxylique, dianhydride pyromellitique, dianhydride de benzophénone tétracarboxylique, anhydride oxydiphtalique, dianhydride de cyclobutane 1,2,3,4-tétracarboxylique, dianhydride de cyclopentane tétracarboxylique et dianhydride de bis(3,4-dicarboxyphényl)sulfone.
     
    4. Film de poly(amide-imide) comprenant le copolymère poly(amide-imide) de la revendication 1.
     
    5. Film de poly(amide-imide) de la revendication 4,
    où le film a une dureté au crayon de 2H ou plus, telle que mesurée conformément à la norme ASTM D3363 avec un spécimen ayant une épaisseur de 30 ± 2 µmol et
    un indice de jaunissement (YI) de 3,0 ou moins, tel que mesuré conformément à la norme ASTM D1925.
     
    6. Film de poly(amide-imide) de la revendication 4,
    où le film a un trouble optique de 0,5 % ou moins, tel que mesuré conformément à la norme ASTM D1003 avec un spécimen ayant une épaisseur de 30 ± 2 µm,
    un facteur de transmission de 88,5 % ou plus en ce qui concerne une lumière visible ayant une longueur d'onde de 550 nm et
    un facteur de transmission de 25 % ou moins en ce qui concerne une lumière ultraviolette ayant une longueur d'onde de 388 nm.
     
    7. Copolymère poly(amide-imide) de la revendication 1,
    où le monomère dicarbonyle aromatique est contenu à une quantité, rapportée aux moles totales de monomère diamine aromatique et de monomère dicarbonyle aromatique, qui va de 30 % en moles à 55 % en moles.