BRANCHED COPOLYMER, AND PHOTOSENSITIVE RESIN COMPOSITION, PHOTOSENSITIVE RESIN FILM AND OPTICAL DEVICE USING THE SAME

Abstract

The present invention relates to a branched copolymer having a polyimide polymer block bonded to each terminal of a branched polyamide functional group, and a photosensitive resin composition including the same, a photosensitive resin film, and an optical device.

Claims

1. A branched copolymer comprising: a branched amide functional group represented by Chemical Formula 1; and a polyimide block bonded to a terminal of the branched amide functional group: ##STR00014## wherein, in the Chemical Formula 1, A is a trivalent or higher-valent functional group, a is an integer of 3 or more, and L.sub.1 is a direct bond or a divalent functional group.

2. The branched copolymer according to claim 1, wherein the bivalent group of L.sub.1 is an alkylene group having 5 to 100 carbon atoms; or a polysiloxanylene group having 5 to 100 carbon atoms.

3. The branched copolymer according to claim 2, wherein the polysiloxanylene group having 5 to 100 carbon atoms has a number average molecular weight of 100 g/mol to 1000 g/mol.

4. The branched copolymer according to claim 1, wherein the branched amide functional group includes a functional group represented by Chemical Formula 1-1: ##STR00015## wherein, in the Chemical Formula 1-1, A.sub.1 is a tetravalent group, and L.sub.2 to L.sub.5 are the same as or different from each other, and are each independently a direct bond or a divalent functional group.

5. The branched copolymer according to claim 1, wherein A is an organic group represented by Chemical Formula 2: ##STR00016## wherein, in the Chemical Formula 2, Y is any one selected from the group consisting of a direct bond, O, CO, COO, S, SO, SO.sub.2, CR.sub.7R.sub.8, (CH.sub.2).sub.t, O(CH.sub.2).sub.tO, COO (CH.sub.2).sub.tOCO, CONH, phenylene, and a combination thereof, wherein R.sub.1 to R.sub.8 are each independently hydrogen, or an alkyl group or a haloalkyl group having 1 to 10 carbon atoms, and t is an integer of 1 to 10.

6. The branched copolymer according to claim 1, wherein the polyimide block includes a crosslinking functional group bonded to a polyimide backbone or branched chain.

7. The branched copolymer according to claim 6, wherein the crosslinking functional group is contained in an amount of 5% to 50% by weight based on the total weight of the branched copolymer.

8. The branched copolymer according to claim 1, wherein the polyimide block includes a polyimide repeating unit represented by Chemical Formula 3: ##STR00017## wherein, in the Chemical Formula 3, A.sub.2 is a tetravalent functional group, and L.sub.6 is a divalent functional group substituted by a haloalkyl group and a crosslinking functional group.

9. The branched copolymer according to claim 8, wherein the divalent functional group substituted by a haloalkyl group and a crosslinking functional group is represented by Chemical Formula 4: ##STR00018## wherein, in the Chemical Formula 4, R.sub.11 is an alkylene group substituted with a haloalkyl group, and at least one of X.sub.1 and X.sub.2 is a crosslinking functional group, and the remainder is hydrogen.

10. The branched copolymer according to claim 1, wherein the branched copolymer includes a copolymer represented by Chemical Formula 5 or a copolymer represented by Chemical Formula 6: ##STR00019## wherein, in the Chemical Formulae 5 and 6, A.sub.4 is a trivalent or higher-valent functional group, a1 is an integer of 3 or more, L.sub.7 is a divalent functional group, A.sub.4 is a tetravalent group, L.sub.8 is a divalent functional group substituted by a haloalkyl group and a crosslinking functional group, and n1 is an integer of 1 to 10,000.

11. The branched copolymer according to claim 1, wherein the branched copolymer has a weight average molecular weight of 1000 g/mol to 1,000,000 g/mol.

12. A photosensitive resin composition comprising the branched copolymer of claim 1.

13. A photosensitive resin film comprising a heat-cured product of the photosensitive resin composition of claim 12.

14. The photosensitive resin film according to claim 13, wherein a temperature for the heat-curing of the photosensitive resin film is 250 C. or less.

15. An optical device comprising the photosensitive resin film of claim 13.

Description

BRIEF DESCRIPTION OF DRAWINGS

[0103] FIG. 1 shows .sup.1H NMR spectrum of the compound of Chemical Formula a synthesized in Example 1.

[0104] FIG. 2 shows the size distribution of copolymers obtained in Example 1 and Reference Example 1.

DETAILED DESCRIPTION OF THE EMBODIMENTS

[0105] Hereinafter, the present invention will be described in more detail by way of examples. However, these examples are for illustrative purposes only and are not intended to limit the scope of the present invention.

EXAMPLES

Example 1

[0106] A 250 mL flask equipped with a Dean-Stark apparatus was prepared, in which 0.33 g (0.64 mmol) of 9,10-dioctylnonadecane-1,19-diamine was dissolved in diethylene glycol methyl ethyl ether (MEDG), and then 0.05 g (0.16 mmol) of 4,4-oxydiphthalic anhydride was added thereto. The mixture was reacted at 150 C. for 2 hours in a nitrogen atmosphere to synthesize a compound represented by the following Chemical Formula a.

##STR00011##

[0107] In Chemical Formula a, Q.sub.1 to Q.sub.4 are all 9,10-dioctylnonadecane-1,19-diyl. For reference, .sup.1H NMR spectrum results of the compound represented by Chemical Formula a are shown in FIG. 1.

[0108] Then, 16.5 g (0.053 mol) of 4,4-oxydiphthalic anhydride and 20 g (0.055 mol) of 2,2-bis(3-amino-4-hydroxyphenyl)hexafluoropropane were added to the compound represented by Chemical Formula a, and then diethylene glycol methyl ethyl ether (MEDG) and toluene were added so that the solid content was 30 wt %, and the mixture was reacted at 150 C. for 12 hours to synthesize a branched copolymer.

[0109] After completion of the reaction, 98.5 g of a photosensitive resin composition in which the branched copolymer was dissolved in the MEDG solvent was obtained. The molecular weight of the branched copolymer was measured by GPC using a THF solvent, and as a result, a number average molecular weight (Mn=3000 g/mol) and a weight average molecular weight (Mw=5500 g/mol) were found.

Example 2

[0110] A branched copolymer and a photosensitive resin composition were obtained in the same manner as in Example 1, except that a compound represented by the following Chemical Formula b was used instead of the compound represented by Chemical Formula a in Example 1.

##STR00012##

[0111] In Chemical Formula b, Q.sub.5 to Q.sub.8 are all 9,10-dioctylnonadecane-1,19-diyl.

[0112] A 250 mL flask equipped with a Dean-Stark apparatus was prepared, in which 0.48 g (0.92 mmol) of 9,10-dioctylnonadecane-1,19-diamine was dissolved in diethylene glycol methyl ethyl ether (MEDG), and then 0.05 g (0.22 mmol) of pyromellitic dianhydride was added thereto. The mixture was reacted at 150 C. for 2 hours in a nitrogen atmosphere to synthesize a compound represented by Chemical Formula b.

[0113] The molecular weight of the branched copolymer was measured by GPC using a THF solvent, and as a result, a number average molecular weight (Mn=1000 g/mol) and a weight average molecular weight (Mw=3000 g/mol) were found.

Example 3

[0114] A branched copolymer and a photosensitive resin composition were obtained in the same manner as in Example 1, except that 0.28 g (0.64 mmol) of polydimethylsiloxanyl diamine (Mn=430 g/mol) instead of 9,10-dioctylnonadecane-1, 19-diamine was dissolved in diethylene glycol methyl ethyl ether (MEDG), and then reacted with 0.05 g (0.16 mmol) of 4,4-oxydiphthalic anhydride in Example 1. The molecular weight of the branched copolymer was measured by GPC using a THF solvent, and as a result, a number average molecular weight (Mn=5000 g/mol) and a weight average molecular weight (Mw=100,000 g/mol) were found.

Example 4

[0115] A branched copolymer and a photosensitive resin composition were obtained in the same manner as in Example 1, except that 3.3 g (6.4 mmol) of 9,10-dioctylnonadecane-1, 19-diamine was added and reacted in Example 1. The molecular weight of the branched copolymer was measured by GPC using a THF solvent, and as a result, a number average molecular weight (Mn=16,000 g/mol) and a weight average molecular weight (Mw=35,000 g/mol) were found.

COMPARATIVE EXAMPLE

Comparative Example 1

[0116] A branched copolymer and a photosensitive resin composition were obtained in the same manner as in Example 1, except that a compound represented by the following Chemical Formula c (1,3,5-triazine-2,4,6-triamine) was used instead of the compound represented by Chemical Formula a in Example 1.

##STR00013##

REFERENCE EXAMPLE

Reference Example 1

[0117] A 250 mL flask equipped with a Dean-Stark apparatus was prepared, in which 0.3 g of 9,10-dioctylnonadecane-1,19-diamine, 16.9 g of 4,4-oxydiphthalic anhydride, and 20 g of 2,2-bis(3-amino-4-hydroxyphenyl)hexafluoropropane were added to diethylene glycol methyl ethyl ether (MEDG) and toluene, and the mixture was reacted at 150 C. for 12 hours to obtain a linear polyimide copolymer. The molecular weight of the linear polyimide copolymer was measured by GPC using a THF solvent, and as a result, a number average molecular weight (Mn=25,000 g/mol) and a weight average molecular weight (Mw=32,000 g/mol) were found.

EXPERIMENTAL EXAMPLES

Experimental Example 1

[0118] The photosensitive resin compositions obtained in the examples and comparative examples above were coated onto a 4-inch silicon wafer using a spin coating method at 800 to 1200 rpm, and then dried at a temperature of 120 C. for 2 minutes to obtain a substrate on which a photosensitive resin film having a thickness of 5.0 m was formed.

[0119] Then, the substrate was exposed to an energy of 500 mJ/cm.sup.2 by a broadband aligner exposure apparatus using a mask having a fine pattern formed thereon. Thereafter, the exposed substrate was developed in a 2.38 wt % tetramethylammonium hydroxide aqueous solution for 150 seconds, washed with ultrapure water, and then dried under nitrogen to form a pattern on the photosensitive resin film. Then, the resultant was cured again at a temperature of 200 C. for 2 hours to obtain a substrate on which a patterned photosensitive resin film was formed.

[0120] The thus-obtained substrate on which a patterned photosensitive resin film was formed was immersed in a solvent selected from acetone, DMF, and GBL for 30 minutes, washed with isopropyl alcohol, and dried under nitrogen. Then, the surface condition of the patterned photosensitive resin film was grasped through a microscope, and the chemical resistance was evaluated under the following criteria, and the results are shown in Table 1 below.

[0121] Excellent: There is no damage like melted marks or cracks.

[0122] Defective: There is damage such as melted marks or cracks

TABLE-US-00001 TABLE 1 Measurement Results of Experimental Example 1 of Examples and Comparative Examples Category Acetone DMF GBL Example 1 Excellent Excellent Excellent Example 2 Excellent Excellent Excellent Example 3 Excellent Excellent Excellent Example 4 Excellent Excellent Excellent Comparative Defective Defective Defective Example 1

[0123] As shown in Table 1, the photosensitive resin films obtained from the copolymers of Examples 1 to 4 containing a branched amide functional group exhibited excellent chemical resistance to all solvents of acetone, DMF, and GBL, whereas the photosensitive resin films obtained from the copolymers of Comparative Example 1 containing no amide functional group exhibited defective chemical resistance to all solvents of acetone, DMF, and GBL as compared with the examples.

Experimental Example 2

[0124] The photosensitive resin compositions obtained in the examples and comparative examples above were coated onto a 4-inch silicon wafer using a spin coating method at about 1000 rpm, and then dried at a temperature of 120 C. for about 2 minutes and cured at 200 C. for about 1 hour to obtain a photosensitive resin film having a thickness of 10 m to 15 m, and then the silicon wafer was removed to secure a photosensitive resin film.

[0125] With respect to the photosensitive resin film, the ultimate tensile strength (MPa), tensile elongation (%), and elastic modulus (GPa) were respectively measured according to the ASTM D 882 Test Method using a Universal testing machine. The measurement results are shown in Table 2 below.

TABLE-US-00002 TABLE 2 Measurement Results of Experimental Example 2 of Examples and Comparative Examples Ultimate tensile Tensile Elastic strength elongation modulus Category (MPa) (%) (GPa) Example 1 140 7.4 3.6 Example 2 122 6.8 3.2 Example 3 128 6.5 3.1 Example 4 126 7.6 3.1 Comparative 37 1.9 2.8 Example 1

[0126] As shown in Table 2 above, the photosensitive resin films obtained from the copolymers of Examples 1 to 4 containing the branched amide functional group exhibited an ultimate tensile strength of 122 MPa to 140 MPa, tensile elongation of 6.5% to 7.6%, and an elastic modulus of 3.1 GPa to 3.6 GPa, thereby realizing excellent mechanical properties. On the other hand, the photosensitive resin film obtained from the copolymer of Comparative Example 1 containing no amide functional group exhibited an ultimate tensile strength of 37 MPa, tensile elongation of 1.9%, and an elastic modulus of 2.8 GPa, confirming that the mechanical properties were defective as compared with those of the examples.

Experimental Example 3

[0127] For the branched copolymer obtained in Example 1 and the linear copolymer obtained in Reference Example 1, the hydrodynamic size distribution of the copolymer was measured in solution phase with a dynamic light scattering (DLS) analyzer, and the results are shown in FIG. 2.

[0128] Looking at FIG. 2, in the case of the two-dimensional linear copolymer obtained in Reference Example 1, an average particle size was measured at 25 nm, whereas in the case of the branched copolymer obtained in Example 1, the average particle size which is larger than that of Reference Example 1 was measured at 100 nm, confirming that the copolymer of Example 1 has a branched three-dimensional structure.