POLYAMIDE-IMIDE BLOCK COPOLYMERS, PREPARATION METHOD THEREOF AND POLYAMIDE-IMIDE FILM COMPRISING THE SAME

Abstract

The polyamide-imide block copolymer according to the present invention makes it possible to provide a polyamide-imide film having excellent thermal stability and chemical resistance and, at the same time, having excellent mechanical properties.

Claims

1. A polyamide-imide block copolymer comprising: a first repeat unit represented by the following Chemical Formula 1, a second repeat unit represented by the following Chemical Formula 2 and a third repeat unit represented by the following Chemical Formula 3: ##STR00020## wherein, in the Chemical Formulae 1 to 3, each A is the same as or different from each other in each repeat unit, and is a substituted or unsubstituted tetravalent organic group, E.sup.1, E.sup.2, E.sup.3, E.sup.4, E.sup.5, E.sup.6 and E.sup.7 are the same as or different from each other in each repeat unit, and are a single bond or —NH—, each Z.sup.1 is the same as or different from each other in each repeat unit, and is a trivalent organic group derived from at least one compound selected from the group consisting of triacyl halide, triamine and tricarboxylic acid, each Z.sup.2 is the same as or different from each other in each repeat unit, and is a divalent organic group derived from at least one compound selected from the group consisting of diacyl halide, diamine and dicarboxylic acid, and Y.sup.1, Y.sup.2, and Y.sup.3 are the same as or different from each other in each repeat unit, and each independently, a divalent aromatic organic group having 6 to 30 carbon atoms, wherein the divalent aromatic organic group exists alone; or two or more aromatic organic groups are bonded to each other to form a divalent condensed ring; or two or more aromatic organic groups are linked by a single bond, a fluorenylene group, —O—, —S—, —C(═O)—, —CH(OH)—, —S(═O).sub.2—, —Si(CH.sub.3).sub.2—, —(CH.sub.2).sub.p— (where 1≤p≤10), —(CF.sub.2).sub.q— (where 1≤q≤10), —C(CH.sub.3).sub.2—, —C(CF.sub.3).sub.2—, or —C(═O)NH—, with the proviso that at least one of Y.sup.1, Y.sup.2 and Y.sup.3 is substituted with one or more photocurable functional groups selected from the group consisting of a (meth)acrylate group and a functional group represented by the following Chemical Formula 4, ##STR00021## each R.sup.1 is the same as or different from each other in each repeat unit, and is hydrogen or an alkyl group having 1 to 10 carbon atoms, and each L is the same as or different from each other in each repeat unit, and is a single bond or an alkylene having 1 to 10 carbon atoms, wherein the sum of the repeat units in which Y.sup.1, Y.sup.2 and Y.sup.3 are substituted with the photocurable functional group is 10 mol % to 80 mol % based on 100 moles of the total repeat units.

2. The polyamide-imide block copolymer according to claim 1, wherein the sum of the repeat units in which Y.sup.1, Y.sup.2 and Y.sup.3 are substituted with the photocurable functional group is 30 mol % to 70 mol % based on 100 moles of the total repeat units.

3. The polyamide-imide block copolymer according to claim 1, wherein each of the Y.sup.1, Y.sup.2 and Y.sup.3 is a group represented by the following Chemical Formula Y-1 or Y-2: ##STR00022## wherein, in the Chemical Formula Y-1 and Chemical Formula Y-2, R.sup.3 are each independently a (meth)acrylate group or a functional group represented by the following Chemical Formula 4, ##STR00023## each R.sup.1 is the same as or different from each other in each repeat unit, and is hydrogen or an alkyl group having 1 to 10 carbon atoms, each L is the same as or different from each other in each repeat unit, and is a single bond or an alkylene having 1 to 10 carbon atoms, n3, n4 and n5 are each independently 0 to 4, with the proviso that at least one of n3, n4 and n5 is 1 or more, and each R.sup.4 is independently a single bond, —O—, —S—, —C(═O)—, —CH(OH)—, —S(═O).sub.2—, —Si(CH.sub.3).sub.2—, —(CH.sub.2).sub.p— (where 1≤p≤1), —(CF.sub.2).sub.q— (where 1≤q≤10), —C(CH.sub.3).sub.2—, —C(CF.sub.3).sub.2—, or —C(═O)NH—.

4. The polyamide-imide block copolymer according to claim 1, wherein A is any one selected from groups represented by the following: ##STR00024## ##STR00025##

5. The polyamide-imide block copolymer according to claim 1, wherein the Z.sup.1 is any one selected from groups represented by the following: ##STR00026##

6. The polyamide-imide block copolymer according to claim 1, wherein the Z.sup.2 is any one selected from groups represented by the following: ##STR00027##

7. The polyamide-imide block copolymer according to claim 1, wherein the first repeat unit includes a repeat unit represented by Chemical Formula 1-1: ##STR00028## wherein, in the Chemical Formula 1-1, Y.sup.1 is as defined in claim 1.

8. The polyamide-imide block copolymer according to claim 1, wherein the second repeat unit includes a repeat unit represented by Chemical Formula 2-1: ##STR00029## wherein, in the Chemical Formula 2-1, Y.sup.2 is as defined in claim 1.

9. The polyamide-imide block copolymer according to claim 1, wherein the third repeat unit includes a repeat unit represented by Chemical Formula 3-1: ##STR00030## wherein, in the Chemical Formula 3-1, Y.sup.3 is as defined in claim 1.

10. The polyamide-imide block copolymer according to claim 1, wherein a molar ratio of the sum of the second repeat unit and the third repeat unit is 10:90 to 90:10 relative to the first repeat unit.

11. The polyamide-imide block copolymer according to claim 1, wherein a weight average molecular weight is 5,000 to 300,000 g/mol.

12. A method for preparing a polyamide-imide block copolymer comprising the steps of: reacting a diamine compound with a dianhydride compound to form a polyamic acid block; mixing at least one compound selected from the group consisting of triacyl halide, triamine and tricarboxylic acid and at least one compound selected from the group consisting of aromatic diacyl halide, aromatic diamine and aromatic dicarboxylic acid with the polyamic acid block, and reacting them to form a polyamide block; and adding at least one compound of a compound containing a (meth)acrylate group and a compound containing a functional group represented by the following Chemical Formula 4 to the mixture containing the polyamic acid block and the polyamide block to perform imidization, wherein the diamine compound substituted with a hydroxyl group is contained in an amount of 10 mol % to 80 mol % based on 100 moles of the total diamine compound. ##STR00031## wherein each R.sup.1 is the same or different from each repeating unit, and is hydrogen or an alkyl group having 1 to 10 carbon atoms, and each L is the same or different from each repeating unit and is a single bond or an alkylene having 1 to 10 carbon atoms.

13. The method for preparing a polyamide-imide block copolymer according to claim 12, wherein the compound containing a (meth)acrylate group is (meth)acrylic anhydride, and the compound containing the functional group represented by the Chemical Formula 4 is 2-isocyanatoethyl (meth)acrylate.

14. The method for preparing a polyamide-imide block copolymer according to claim 12, wherein in the imidization step, the hydroxyl group contained in the polyamic acid block and the polyamide block is substituted with a (meth)acrylate group or the functional group represented by the Chemical Formula 4.

15. The method for preparing a polyamide-imide block copolymer according to claim 12, wherein the imidization step is performed at 20° C. to 100° C.

16. A polyamide-imide film comprising the polyamide-imide block copolymer according to claim 1.

17. The polyamide-imide film according to claim 16, wherein a yellowness index (Y.I.) according to ASTM D1925 is 1.5 to 1.75.

18. The polyamide-imide film according to claim 16, wherein a modulus according to ASTM D648 is 4.0 GPa to 5.0 GPa.

Description

DETAILED DESCRIPTION OF THE EMBODIMENTS

[0110] 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.

[PREPARATION EXAMPLE]—PREPARATION OF POLYAMIDE-IMIDE BLOCK COPOLYMER

Preparation Example 1

[0111] While passing nitrogen through a four-necked round bottomed flask equipped with a mechanical stirrer, a nitrogen inlet, a temperature controller and a cooler, 3.63 g (9.91 mmol) of 2,2-bis(3-amino-4-hydroxyphenyl)hexafluoropropane (BisAPAF) and 6.34 g (19.8 mmol) of 2,2′-bis(trifluoromethyl)-4,4′-diamino biphenyl (TFMB)] were dissolve in 183 g of N-methyl-2-pyrrolidone (NMP). Then, 8.00 g (18.0 mmol) of 4,4′-(hexafluoroisopropylidene)diphthalic anhydride (6FDA) was added thereto, and the mixture was stirred at 40° C. for about 3 hours. 2.38 g (11.7 mmol) of terephthaloyl chloride (TPC) were added and then 0.05 g (0.188 mmol) of 1,3,5-benzenetricarbonyl trichloride (BTT) was further added, and then stirred for 3 hours. Then, 3.47139 g (15.76 mmol) of butylated hydroxy toluene (BHT), 35.60 g (450 mmol) of pyridine and 34.69 g (225 mmol) of methacrylic anhydride were added, and then stirred at 60° C. overnight. After the reaction was completed, excess ethanol (2 L) was added dropwise to the stirring reaction solution to form a precipitate. The obtained precipitate was separated by filtration under reduced pressure, washed three times with ethanol, and then dried at room temperature under vacuum for about 24 hours to obtain 15 g of a polyamide-imide copolymer (A-1) having a methacrylate group.

[0112] As a result of 1H-NMR analysis, the polyamide-imide copolymer (A-1) was calculated by those in which all the hydroxyl groups (—OH) were substituted with methacrylate groups. Accordingly, it was confirmed that the molar ratio of the repeat units substituted with methacrylate was 33 mol %.

Preparation Example 2

[0113] 16 g of polyamide-imide copolymer (A-2) was obtained in the same manner in Preparation Example 1, except that a molar ratio of 2,2′-bis(3-amino-4-hydroxyphenyl)-hexafluoropropane:2,2′-bis(trifluoromethyl)-4,4′-diamino biphenyl was changed to 0.20:0.79 instead of 0.33:0.66.

[0114] As a result of 1H-NMR analysis, the polyamide-imide copolymer (A-2) was calculated by those in which all the hydroxyl groups (—OH) were substituted with methacrylate groups. Accordingly, it was confirmed that the molar ratio of the repeat units substituted with methacrylate was 20 mol %.

Preparation Example 3

[0115] 16 g of polyamide-imide copolymer (A-3) was obtained in the same manner in Preparation Example 1, except that a molar ratio of 2,2′-bis(3-amino-4-hydroxyphenyl)-hexafluoropropane:2,2′-bis(trifluoromethyl)-4,4′-diamino biphenyl was changed to 0.5:0.49 instead of 0.33:0.66.

[0116] As a result of 1H-NMR analysis, the polyamide-imide copolymer (A-3) was calculated by those in which all the hydroxyl groups (—OH) were substituted with methacrylate groups. Accordingly, it was confirmed that the molar ratio of the repeat units substituted with methacrylate was 50 mol %.

Preparation Example 4

[0117] 15 g of polyamide-imide copolymer (A-4) was obtained in the same manner in Preparation Example 1, except that 225 mmol of 2-isocyanatoethyl (meth)acrylate was used instead of 225 mmol of methacrylic anhydride. Accordingly, it was confirmed that a molar ratio of the repeat units substituted with

##STR00017##

was 33 mol %.

Comparative Preparation Example 1

[0118] While passing nitrogen through a four-necked round bottomed flask equipped with a mechanical stirrer, a nitrogen inlet, a temperature controller and a cooler, 3.63 g (9.91 mmol) of 2,2-bis(3-amino-4-hydroxyphenyl)hexafluoropropane (BisAPAF) and 6.34 g (19.8 mmol) of 2,2′-bis(trifluoromethyl)-4,4′-diamino biphenyl (TFMB) were dissolve in 183 g of N-methyl-2-pyrrolidone (NMP). Then, 8.00 g (18.0 mmol) of 4,4′-(hexafluoroisopropylidene)diphthalic anhydride (6FDA) was added thereto, and the mixture was stirred at 40° C. for about 3 hours. 2.44 g (12.001 mmol) of terephthaloyl chloride (TPC) was further added, and then stirred for 3 hours. Then, 1.39 g (15.76 mmol) of butylated hydroxy toluene (BHT), 35.60 g (450 mmol) of pyridine and 34.69 g (225 mmol) of methacrylic anhydride were added, and then stirred at 60° C. overnight. After the reaction was completed, excess ethanol (2 L) was added dropwise to the stirring reaction solution to form a precipitate. The obtained precipitate was separated by filtration under reduced pressure, washed three times with ethanol, and then dried at room temperature under vacuum for about 24 hours to obtain 15 g of a polyamide-imide copolymer (B-1) having a methacrylate group.

[0119] As a result of 1H-NMR analysis, the polyamide-imide copolymer (B-1) was calculated by those in which all the hydroxyl groups (—OH) were substituted with methacrylate groups. Accordingly, it was confirmed that a molar ratio of the repeat units substituted with methacrylate was 33 mol %.

Comparative Preparation Example 2

[0120] 15 g of polyamide-imide copolymer (B-2) was obtained in the same manner in Preparation Example 1, except that a molar ratio of 2,2′-bis(3-amino-4-hydroxyphenyl)-hexafluoropropane:2,2′-bis(trifluoromethyl)-4,4′-diamino biphenyl was changed to 0.05:0.94 instead of 0.33:0.66.

[0121] As a result of 1H-NMR analysis, the polyamide-imide copolymer (B-2) was calculated by those in which all the hydroxyl groups (—OH) were substituted with methacrylate groups. Accordingly, it was confirmed that a molar ratio of the repeat units substituted with methacrylate was 5 mol %.

Comparative Preparation Example 3

[0122] 15 g of polyamide-imide copolymer (B-3) was obtained in the same manner in Preparation Example 1, except that a molar ratio of 2,2′-bis(3-amino-4-hydroxyphenyl)-hexafluoropropane:2,2′-bis(trifluoromethyl)-4,4′-diamino biphenyl was changed to 0.90:0.09 instead of 0.33:0.66.

[0123] As a result of 1H-NMR analysis, the polyamide-imide copolymer (B-3) was calculated by those in which all the hydroxyl groups (—OH) were substituted with methacrylate groups. Accordingly, it was confirmed that a molar ratio of the repeat units substituted with methacrylate was 90 mol %.

Comparative Preparation Example 4

[0124] A polyimide-based block copolymer (B-4) containing a repeat unit represented by the following Chemical Formula a-1 and a repeat unit represented by the following Chemical Formula a-2 were used. The molar ratio of the repeat unit of the Chemical Formula a-1 to the repeat unit of the Chemical Formula a-2 is 50:50.

##STR00018##

Example and Comparative Example

[0125] Polyamide-imide block copolymer samples obtained in the Preparation Examples and Comparative Preparation Examples were dissolved in methyl ethyl ketone (MEK) to prepare about 15 wt % of a solution. The solution was subjected to casting on a glass plate through a bar coater equipment. At this time, the drying was performed at a temperature of 90° C. for 15 minutes, and then photocured using a UV curing machine. Then, the heat treatment was performed at 170° C. for 15 minutes and peeled to prepare polyamide-imide films of Examples and Comparative Examples having a thickness of 50 μm.

TABLE-US-00001 TABLE 1 Weight Whether to Photocurable average include a 3D functional molecular brancher group weight of Catagory Copolymer structure (mol %)* copolymer Example 1 A-1 ◯ a-1/33%  35,700 Example 2 A-2 ◯ a-1/20%  42,800 Example 3 A-3 ◯ a-1/50%  39,900 Example 4 A-4 ◯ a-2/33%  36,800 Comparative B-1 X a-1/33%  38,200 Example 1 Comparative B-2 ◯ a-1/5%   47,000 Example 2 Comparative B-3 ◯ a-1/90%  39,800 Example 3 Comparative B-4 ◯ a-3/50% 490,000 Example 4 *Represents the content of the total sum of repeat units substituted with a photocurable functional group, a-1 is a structure in which a methacrylate group is substituted with a photocurable functional group, a-2 is a structure in which [00019]is substituted, and a-3 is a structure in which a carboxy group is substituted.

Experimental Example

[0126] The physical properties of the polyamide-imide film prepared in Examples and Comparative Examples were evaluated by the following methods, and the results are shown in Table 2 below.

[0127] 1) Yellowness Index

[0128] The yellowness index of the polyamide-imide film samples (thickness of 50±2 μm) prepared in Examples and Comparative Examples was measured in accordance with ASTM D1925 using a COH-400 Spectrometer (NIPPON DENSHOKU INDUSTRIES), and the values are shown in Table 2 below.

[0129] 2) Glass Transition Temperature (Tg)

[0130] The glass transition temperature of the polymer film samples (thickness of 50±2 μm) prepared in Examples and Comparative Examples was measured using a TMA IC600 device, and the values are shown in Table 2 below.

[0131] 3) Modulus

[0132] The modulus (GPa) of the polymer film samples (thickness of 50±2 μm) prepared in Examples and Comparative Examples was measured using DMA q800, and the results are shown in Table 2 below.

[0133] 4) Chemical Resistance

[0134] The chemical resistance was evaluated for the polymer film samples (thickness of 50±2 μm) prepared in Examples and Comparative Examples.

[0135] The prepared film samples were immersed in acetone and N-methyl-1,2-pyrrolidone (NMP), respectively, and then allowed to stand at room temperature (25° C.) for 5 minutes, and then taken out. The change of the film was evaluated according to the following criteria.

[0136] <Evaluation Criteria>

[0137] ∘ Excellent—No change in film

[0138] Δ Normal—Change observed (partial swelling)

[0139] X Poor—Film surface melted

TABLE-US-00002 TABLE 2 Yellowness Glass transition Modulus Chemical Category index temperature (° C.) (GPa) resistance Example 1 1.69 187 4.56 ◯ Example 2 1.69 180 4.20 ◯ Example 3 1.72 188 4.08 ◯ Example 4 1.75 175 4.00 ◯ Comparative 1.79 160 3.90 ◯ Example 1 Comparative 1.62 165 3.81 X Example 2 Comparative 2.28 179 3.42 ◯ Example 3 Comparative 2.05 152 3.15 X Example 4

[0140] As can be seen in Table 2, it was confirmed that when using a copolymer containing a specific repeat unit and a specific molar ratio of a photocurable functional group according to the present invention, it has excellent thermal stability and chemical resistance, and at the same time, has excellent mechanical properties, and can realize excellent optical properties.

[0141] It was confirmed that in Comparative Example 1, a copolymer not containing a three-dimensional crosslinked structure is used, and thereby, all properties are deteriorated compared to those of Examples of the present invention.

[0142] It was confirmed that in Comparative Example 2, the repeat unit containing the photocurable functional group is only 5 mol %, and thus, the chemical resistance and durability are lowered compared to those of the Examples.

[0143] It was confirmed that in Comparative Example 3, the repeat unit containing the photocurable functional group is 90 mol %, and the over-cured film is very brittle and can be cracked, which results in a decrease in physical properties compared to those of the Examples.

[0144] It was confirmed that Comparative Example 4 is a case where the carboxy group terminal was included instead of the photocurable functional group of the present invention, the transparency of the thin film is remarkably reduced, and the physical properties are lowered compared to those of the Examples.