POLYIMIDE-BASED BLOCK COPOLYMERS AND POLYIMIDE-BASED FILM COMPRISING THE SAME

Abstract

The present disclosure relates to a polyimide-based block copolymer and a polyimide-based film including the same. The polyimide-based block copolymer according to the present disclosure makes it possible to provide a polyimide-based film having a large molecular weight and exhibiting colorless and transparent properties.

Claims

1. A polyimide-based block copolymer comprising a first repeating unit represented by Chemical Formula 1, and a second repeating unit represented by Chemical Formula 2: ##STR00012## wherein, in Chemical Formulae 1 and 2, L.sup.1 and L.sup.2 are the same as or different from each other in each repeating unit, and each 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 (wherein 1p10), (CF.sub.2).sub.q (wherein 1q10), C(CH.sub.3).sub.2, C(CF.sub.3).sub.2, C(O)NH, or a C6 to C30 divalent aromatic organic group; R.sup.1 and R.sup.2 are independently F, Cl, Br, I, CF.sub.3, CCl.sub.3, CBr.sub.3, Cl.sub.3, NO.sub.2, CN, COCH.sub.3, CO.sub.2C.sub.2H.sub.5, a silyl group containing three C1 to C10 aliphatic organic groups, a C1 to C10 aliphatic organic group, or a C6 to C20 aromatic organic group; n1 and n2 are independently 0 to 3; Ar.sup.1 and Ar.sup.2 are the same as or different from each other in each repeating unit, and each is independently a C6 to C30 divalent aromatic organic group, wherein at least one of Ar.sup.1 and Ar.sup.2 comprises a C6 to C30 divalent aromatic organic group substituted with at least one of an acetate group (CH.sub.3COO) and a hydroxyl group (HO), and the divalent aromatic organic group exists alone, or two or more aromatic organic groups are bonded to each other to form a condensed ring, or two or more aromatic organic groups are linked by a single bond, O, S, C(O), CH(OH), S(O).sub.2, Si(CH.sub.3).sub.2, (CH.sub.2).sub.p (wherein 1p10), (CF.sub.2).sub.q (wherein 1q10), C(CH.sub.3).sub.2, C(CF.sub.3).sub.2, or C(O)NH; E.sup.1 to E.sup.4 are independently a single bond, NH, or C(O); and each Z.sup.1 is the same as or different from each other in each repeating unit, and each is independently a trivalent linking group derived from at least one compound selected from the group consisting of triacyl halide, triamine, and tricarboxylic acid.

2. The polyimide-based block copolymer of claim 1, wherein Ar.sup.1 and Ar.sup.2 are independently a group represented by Chemical Formula Ar(A) or Ar(B): ##STR00013## wherein, in Chemical Formulae Ar(A) and Ar(B), each R.sup.3 is independently OH, F, Cl, Br, I, CF.sub.3, CCl.sub.3, CBr.sub.3, Cl.sub.3, NO.sub.2, CN, COCH.sub.3, CH.sub.3COO, CO.sub.2C.sub.2H.sub.5, a silyl group containing three C1 to C10 aliphatic organic groups, a C1 to C10 aliphatic organic group, or a C6 to C20 aromatic organic group, wherein at least one of R.sup.3 included in Ar.sup.1 and Ar.sup.2 is an acetate group (CH.sub.3COO) or a hydroxyl group (HO); n3 is independently 0 to 4, wherein at least one of n3 included in Ar.sup.1 and Ar.sup.2 is 1 or more; and L.sup.3 is a single bond, O, S, C(O), CH(OH), S(O).sub.2, Si(CH.sub.3).sub.2, (CH.sub.2).sub.p (wherein 1p10), (CF.sub.2).sub.q (wherein 1q10), C(CH.sub.3).sub.2, C(CF.sub.3).sub.2, or C(O)NH.

3. The polyimide-based block copolymer of claim 1, wherein Ar.sup.2 comprises a C6 to C30 divalent aromatic organic group substituted with an acetate group or a hydroxyl group.

4. The polyimide-based block copolymer of claim 1, wherein Z.sup.1 is a trivalent linking group derived from at least one compound selected from the group consisting of benzene-1,3,5-tricarbonyl trichloride, benzene-1,3,5-tricarboxylic acid, benzene-1,3,5-triamine, benzene-1,2,4-triamine, cyclohexane-1,3,5-triamine, cyclohexane-1,2,4-triamine, and pyrimidine-2,4,6-triamine.

5. The polyimide-based block copolymer of claim 1, wherein Z.sup.1 is at least one selected from the group represented by Chemical Formula Z1: ##STR00014##

6. The polyimide-based block copolymer of claim 1, wherein the first repeating unit comprises a repeating unit represented by Chemical Formula A1, and the second repeating unit comprises a repeating unit represented by Chemical Formula A2: ##STR00015## wherein, in Chemical Formulae A1 and A2, R.sup.1 and R.sup.2 are independently F, Cl, Br, I, CF.sub.3, CCl.sub.3, CBr.sub.3, Cl.sub.3, NO.sub.2, ON, COCH.sub.3, CO.sub.2C.sub.2H.sub.5, a silyl group containing three C1 to C10 aliphatic organic groups, a C1 to C10 aliphatic organic group, or a C6 to C20 aromatic organic group; n1 and n2 are independently 0 to 3; and Ar.sup.1 and Ar.sup.2 are the same as or different from each other in each repeating unit, and each is independently a C6 to C30 divalent aromatic organic group, wherein at least one of Ar.sup.1 and Ar.sup.2 comprises a C6 to C30 divalent aromatic organic group substituted with at least one of an acetate group (CH.sub.3COO) and a hydroxyl group (HO), and the divalent aromatic organic group exists alone, or two or more aromatic organic groups are bonded to each other to form a condensed ring, or two or more aromatic organic groups are linked by a single bond, O, S, C(O), CH(OH), S(O).sub.2, Si(CH.sub.3).sub.2, (CH.sub.2).sub.p (wherein 1p10), (CF.sub.2).sub.q (wherein 1q10), C(CH.sub.3).sub.2, C(CF.sub.3).sub.2, or C(O)NH.

7. The polyimide-based block copolymer of claim 1, wherein the first repeating unit comprises a repeating unit represented by Chemical Formula B1, and the second repeating unit comprises at least one repeating unit selected from the group represented by Chemical Formulae B2, B3, and B4: ##STR00016## wherein, in Chemical Formulae B1 to B4, R.sup.1 and R.sup.2 are independently F, Cl, Br, I, CF.sub.3, CCl.sub.3, CBr.sub.3, Cl.sub.3, NO.sub.2, CN, COCH.sub.3, CO.sub.2C.sub.2H.sub.5, a silyl group containing three C1 to C10 aliphatic organic groups, a C1 to C10 aliphatic organic group, or a C6 to C20 aromatic organic group; n1 and n2 are independently 0 to 3; each R.sup.3 is independently OH, F, Cl, Br, I, CF.sub.3, CCl.sub.3, CBr.sub.3, Cl.sub.3, NO.sub.2, CN, COCH.sub.3, CH.sub.3COO, CO.sub.2C.sub.2H.sub.5, a silyl group containing three C1 to C10 aliphatic organic groups, a C1 to C10 aliphatic organic group, or a C6 to C20 aromatic organic group; and L.sup.3 and L.sup.3 are 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 (wherein 1p10), (CF.sub.2).sub.q (wherein 1q10), C(CH.sub.3).sub.2, C(CF.sub.3).sub.2, or C(O)NH.

8. The polyimide-based block copolymer of claim 1, wherein a weight ratio of the first repeating unit to the second repeating unit is 1:1 to 3:1.

9. The polyimide-based block copolymer of claim 1, wherein a weight average molecular weight is 100,000 to 5,000,000 g/mol.

10. A polyimide-based film comprising the polyimide-based block copolymer according to claim 1.

11. The polyimide-based film of claim 10, wherein the film has a yellow index (YI) of 2.0 or less, as measured in accordance with ASTM E313.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0092] FIG. 1 is an NMR spectrum of the polyimide-based copolymer obtained in Example 1.

[0093] FIG. 2 is an NMR spectrum of the polyimide-based copolymer obtained in Example 3.

[0094] FIG. 3 is an NMR spectrum of the polyimide-based copolymer obtained in Comparative Example 2.

DETAILED DESCRIPTION OF THE EMBODIMENTS

[0095] 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

[0096] 4.851 g (1.01 eq., 0.01515 mol) of 2,2-bis(trifluoromethyl)benzidine; 6.5970 g (0.99 eq., 0.001485 mol) of 4,4-(hexafluoroisopropylidene)diphthalic anhydride; 0.040 g (0.005 eq., 0.000151 mol) of benzene-1,3,5-tricarbonyl trichloride; and 58 ml of dimethylacetamide were placed in a 500 mL round flask equipped with a Dean-Stark apparatus and a condenser, and the reaction was initiated at room temperature. The reaction mixture was stirred using ice water at 0 C. for 4 hours under a nitrogen atmosphere.

[0097] After 4 hours, the reaction product was taken out and raised to room temperature, and 5.4390 g (0.99 eq., 0.01485 mol) of 2,2-bis(3-amino-4-hydroxyphenyl) hexafluoropropane, 6.7302 g (1.01 eq., 0.001515 mol) of 4,4-(hexafluoroisopropylidene)diphthalic anhydride, and 120 ml of dimethylacetamide were added thereto, and the reaction was initiated at room temperature under a nitrogen atmosphere.

[0098] After the formation of a polyamic acid polymer by the reaction for 4 hours, 10 ml (0.099 mol) of acetic anhydride and 8 ml of pyridine (0.099 mol) were added to the reaction mixture, and the mixture was stirred in an oil bath at 40 C. for 15 hours to carry out the chemical imidization reaction.

[0099] After completion of the reaction, the reaction product was precipitated with water and ethanol to obtain a polyimide-based block copolymer having the following repeating units (weight average molecular weight: about 490,000 g/mol).

##STR00009##

Example 2

[0100] A polyimide-based copolymer (weight average molecular weight: about 480,000 g/mol) was obtained in the same manner as in Example 1, except that the content of the benzene-1,3,5-tricarbonyl trichloride was changed to 0.0266 g (0.01 eq., 0.0001 mol).

[0101] .sup.1H NMR (CDCl.sub.3, TMS as standard material) (ppm): 10.854 (s), 8.644 (s), 8.383 (s), 8.256 (m), 8.162 (d), 8.044 (s), 8.017 (d), 7.851 (d), 7.816 (m), 7.7 (d), 7.430 (d)

Example 3

[0102] 4.851 g (1.01 eq., 0.01515 mol) of 2,2-bis(trifluoromethyl)benzidine, 6.546 g (0.9825 eq., 0.001473 mol) of 4,4-(hexafluoroisopropylidene)diphthalic anhydride, 0.01991 g (0.005 eq. 0.000075 mol) of benzene-1,3,5-tricarbonyl trichloride, and 81 ml of dimethylacetamide were placed in a 500 mL round flask equipped with a Dean-Stark apparatus and a condenser, and the mixture was stirred at 4 C. for 4 hours.

[0103] After 4 hours, the reaction product was taken out and raised to room temperature, and 3.211 g (0.99 eq., 0.01485 mol) of 3,3-dihydroxybenzidine, 6.7302 g (1.01 eq., 0.001515 mol) of 4,4-(hexafluoroisopropylidene)diphthalic anhydride, and 71 ml of dimethylacetamide were added thereto, and the reaction was initiated at room temperature under a nitrogen atmosphere.

[0104] After the formation of a polyamic acid polymer by the reaction for 4 hours, 10 ml (0.099 mol) of acetic anhydride and 8 ml of pyridine (0.099 mol) were added to the reaction mixture, and the mixture was stirred in an oil bath at 40 C. for 15 hours to carry out the chemical imidization reaction.

[0105] After completion of the reaction, the reaction product was precipitated with water and ethanol to obtain a polyimide-based block copolymer having the following repeating units (weight average molecular weight: about 200,000 g/mol).

##STR00010##

Comparative Example 1

[0106] A polyimide-based copolymer (weight average molecular weight: about 470,000 g/mol) was obtained in the same manner as in Example 1, except that the benzene-1,3,5-tricarbonyl trichloride was not used in the formation of the copolymer.

Comparative Example 2

[0107] 4.851 g (1.01 eq., 0.01515 mol) of 2,2-bis(trifluoromethyl)benzidine, 6.5970 g (0.99 eq., 0.001485 mol) of 4,4-(hexafluoroisopropylidene)diphthalic anhydride, 0.040 g (0.005 eq., 0.000151 mol) of benzene-1,3,5-tricarbonyl trichloride, and 58 ml of dimethylacetamide were placed in a 500 mL round flask equipped with a Dean-Stark apparatus and a condenser, and the reaction was initiated at room temperature. The reaction mixture was stirred using ice water at 0 C. for 4 hours under a nitrogen atmosphere.

[0108] After the formation of a polyamic acid polymer by the reaction for 4 hours, 10 ml (0.099 mol) of acetic anhydride and 8 ml of pyridine (0.099 mol) were added to the reaction mixture, and the mixture was stirred in an oil bath at 40 C. for 15 hours to carry out the chemical imidization reaction.

[0109] The reaction product was cooled down to room temperature, and precipitated with water to obtain a polyimide-based block copolymer having the following repeating unit (weight average molecular weight: 150,000 g/mol to 300,000 g/mol).

##STR00011##

Preparation Examples 1 to 5

[0110] A film was prepared using the polyimide-based copolymer obtained in Example 1 (Preparation Example 1). A film was prepared using the polyimide-based copolymer obtained in Example 2 (Preparation Example 2). A film was prepared using the polyimide-based copolymer obtained in Example 3 (Preparation Example 3). A film was prepared using the polyimide-based copolymer obtained in Comparative Example 1 (Preparation Example 4). A film was prepared using the polyimide-based copolymer obtained in Comparative Example 2 (Preparation Example 5).

[0111] Specifically, the polyimide-based copolymer was dissolved in dimethylacetamide to prepare a polymer solution of about 20% (w/V). The polymer solution was poured on a glass plate, the thickness of the polymer solution was uniformly controlled using a film applicator, and then dried in a vacuum oven at 120 C. for 12 hours or more to produce a polyimide-based film having a thickness of 20 to 30 m.

Experimental Examples

[0112] A yellow index (Y.I.) of the films of the preparation examples was measured in accordance with ASTM E313 using a COH-400 Spectrophotometer (NIPPON DENSHOKU INDUSTRIES).

TABLE-US-00001 TABLE 1 Preparation Preparation Preparation Preparation Preparation Example 1 Example 2 Example 3 Example 4 Example 5 Y.I. 1.21 1.45 1.25 1.80 2.22

[0113] Referring to the Table 1, it was confirmed that the films of Preparation Examples 1 to 3 had a lower yellow index than the films of Preparation Examples 4 and 5.

[0114] It is presumed that the block copolymers of Examples 1 to 3 maintain a hydrogen bond and a cross-link between the polymer chains well to exhibit excellent mechanical properties and a low yellow index, since they have a well-aligned structure compared with the random copolymer of Comparative Example 2.