BLOCK COPOLYMER

Abstract

The present application relates to a block copolymer and uses thereof. The present application can provide a block copolymer—which exhibits an excellent self-assembling property and thus can be used effectively in a variety of applications—and uses thereof.

Claims

1. A block copolymer comprising a first block (that includes a side chain) and a second block (that is different from the first block), wherein X of Equation 1 below ranges from 2.5 to 10:
X=1+(D×M)/(K×L)  [Equation 1] where in the Equation 1, D represents a ratio (D2/D1) of a density (D2) of the second block to a density (D1) of the first block; M represents a ratio (M1/M2) of a molar mass (M1) of the first block to a molar mass (M2) of the second block; K represents a ratio (A2/A1) in a .sup.1H-NMR spectrum of an area (A2) of a peak that is produced based on the second block to an area (A1) of a peak that is produced based on the first block; and L represents a ratio (H1/H2) of a number (H1) of hydrogen atoms in 1 mole of a repeat unit of the first block to a number (H2) of hydrogen atoms in 1 mole of a repeat unit of the second block.

2. A block copolymer comprising a first block (that includes a side chain) and a second block (that is different from the first block), wherein X of Equation 1 below ranges from 1.1 to 1.7:
X=1+(D×M)/(K×L)  [Equation 1] where in the Equation 1, D represents a ratio (D2/D1) of a density (D2) of the second block to a density (D1) of the first block; M represents a ratio (M1/M2) of a molar mass (M1) of the first block to a molar mass (M2) of the second block; K represents a ratio (A2/A1) in a .sup.1H-NMR spectrum of an area (A2) of a peak that is produced based on the second block to an area (A1) of a peak that is produced based on the first block; and L represents a ratio (H1/H2) of a number (H1) of hydrogen atoms in 1 mole of a repeat unit of the first block to a number (H2) of hydrogen atoms in 1 mole of a repeat unit of the second block.

3. The block copolymer of claim 1 comprising a cylindrical structure.

4. The block copolymer of claim 1, wherein the first block or second block includes an aromatic structure.

5. The block copolymer of claim 1, wherein the first block includes an aromatic structure to which a side chain is connected.

6. The block copolymer of claim 5, wherein the side chain is connected to the aromatic structure by an oxygen atom or a nitrogen atom.

7. The block copolymer of claim 1, wherein the side chain includes 8 or more chain-forming atoms.

8. The block copolymer of claim 1, wherein the first block includes an aromatic structure to which a side chain is connected, and the second block includes an aromatic structure that includes one or more halogen atoms.

9. The block copolymer of claim 1, wherein the first block includes a structural unit represented by Structural Formula 1 below: ##STR00006## where in the Structural Formula 1, R represents a hydrogen atom or an alkyl group with 1 to 4 carbons; X represents a single bond, an oxygen atom, a sulfur atom, —S(═O).sub.2—, a carbonyl group, an alkylene group, an alkenylene group, an alkynylene group, —C(═O)—X.sub.1— or —X.sub.1—C(═O)—, wherein the X.sub.1 represents an oxygen atom, a sulfur atom, —S(═O).sub.2—, an alkylene group, an alkenylene group or an alkynylene group; and Y represents a monovalent substituent that includes a ring structure to which a chain including 8 or more chain-forming atoms is connected.

10. The block copolymer of claim 1, wherein the second block includes a structural unit represented by Structural Formula 3 below: ##STR00007## where in the Structural Formula 3, X.sub.2 represents a single bond, an oxygen atom, a sulfur atom, —S(═O).sub.2—, an alkylene group, an alkenylene group, an alkynylene group, —C(═O)—X.sub.1— or —X.sub.1—C(═O)—, wherein the X.sub.1 represents a single bond, an oxygen atom, a sulfur atom, —S(═O).sub.2—, an alkylene group, an alkenylene group or an alkynylene group; and W represents an aryl group that includes at least one halogen atom.

11. The block copolymer of claim 1 having a number average molecular weight ranging from 3,000 to 300,000.

12. The block copolymer of claim 1 comprising a polydispersity (Mw/Mn) ranging from 1.01 to 1.60.

13. A polymer film comprising the block copolymer of claim 1, wherein the block copolymer is self-assembled.

14. A method of forming a polymer film comprising: forming a polymer film that includes the block copolymer of claim 1 on a substrate, wherein the block copolymer is self-assembled.

15. A method of forming a pattern, the method comprising: removing the first block or second block of the block copolymer of claim 1 from a polymer film that is formed on a substrate and includes the block copolymer, wherein the block copolymer is self-assembled.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0072] Each of FIGS. 1 to 4 is an NMR spectrum of a block copolymer of an example or comparative example.

[0073] Each of FIGS. 5 to 7 is an AFM or SEM image of a self-assembled film of a block copolymer of an example or comparative example.

[0074] FIG. 8 is an image that illustrates an exemplary method for calculating the value of K of Equation 1.

EFFECT

[0075] The present application can provide a block copolymer—which exhibits an excellent self-assembling property or phase separation property and, thus, can be used effectively in a variety of applications—and uses thereof.

DETAILED DESCRIPTION OF EXEMPLARY EMBODIMENTS

[0076] The present application is described in more detail hereinafter through examples according to the present application, but the scope of the present application is not limited to the examples which are proposed hereinafter.

[0077] 1. NMR Measurement

[0078] NMR analysis was carried out at room temperature by using a NMR spectrometer that includes a Varian Unity Inova (500 MHz) spectrometer with a 5-mm triple resonance probe. The analysis subject material was diluted with a solvent (CDCl.sub.3) for an NMR measurement to a concentration of about 10 mg/ml for use, and the chemical shift was expressed in ppm.

[0079] <Applied Abbreviations>

[0080] br=broad signal, s=singlet, d=doublet, dd=doublet of doublets, t=triplet, dt=doublet of triplets, q=quartet, p=quintet, m=multiplet.

[0081] 2. Gel Permeation Chromatography (GPC)

[0082] The number average molecular weight (Mn) and molecular weight distribution were measured by GPC. The analysis subject material such as a macroinitiator or the block copolymer of the examples was put in a 5-mL vial and diluted with tetrahydrofuran (THF) to a concentration of about 1 mg/mL. Then, a standard specimen for calibration and the specimen to be analyzed were filtered with a syringe filter (pore size: 0.45 μm) and subsequently analyzed. ChemStation (Agilent Technologies Inc.) was used as the analytical program, each of the weight average molecular weight (Mw) and Mn was obtained by comparing the elution time of the specimen with the calibration curve, and then a molecular weight distribution (polydispersity index, PDI) was calculated as a ratio (Mw/Mn). The measuring condition of GPC is as follows:

[0083] <GPC Measuring Conditions>

[0084] Device: 1200 Series of Agilent Technologies Inc.

[0085] Column: Two PLgel MIXED-B of Polymer Laboratories

[0086] Solvent: THF

[0087] Column temperature: 35° C.

[0088] Sample concentration: 1 mg/mL, 200 L is injected

[0089] Standard specimen: polystyrene (Mp: 3900000, 723000, 316500, 52200, 31400, 7200, 3940, 485)

[0090] 3. Measurement of X by Equation 1

[0091] Each of the variables of Equation 1—D, M, K and L—can be obtained as follows:

[0092] First of all, D can be obtained by putting a specimen to be analyzed (i.e. a homopolymer that is prepared with only the monomer that constitutes the block 1 or a homopolymer that is prepared with only the monomer that constitutes the block 2) in a solvent (i.e. ethanol) whose mass and density in air are known, obtaining the density of each block through the mass of the specimen, and calculating the ratio of the masses of different types of specimen.

[0093] Also, M can be obtained as the ratio of molar masses of monomers that make up blocks in a block copolymer. For example, in the case of each block copolymer of an example, the molar mass of the monomer of Preparation Example 1, which is the monomer that constitutes the block 1 that will be described below in the present specification, is 346.5 g/mol, the molar mass of pentafluorostyrene that constitutes the block 2 is 194.1 g/mol, and, from the ratio, the value of M can be calculated to be about 1.79.

[0094] In addition, L can be obtained as the ratio of number of hydrogen atoms in the monomers that make up blocks in a block copolymer. For example, in the case of each block copolymer of an example, the number of hydrogen atoms in the monomer of Preparation Example 1, which is the monomer that constitutes the block 1, is 34, the number of hydrogen atoms in pentafluorostyrene that constitutes the block 2 is 3, and, from the ratio, the value of L can be calculated to be about 11.3.

[0095] Lastly, K can be calculated through the area of a spectrum that is obtained by the aforementioned NMR analysis method. In this case, when the peaks—each of which is obtained from each block in a block copolymer—do not overlap each other, the area of the peak derived from each block is simply analyzed, and K can be obtained as the ratio of the peak areas.

[0096] In contrast, when the peaks derived from different blocks of a block copolymer overlap each other at least partly, the overlapped part should be taken into consideration when obtaining the value of K. For example, the accompanying FIG. 8 is an exemplary NMR spectrum of a block copolymer that contains a structural unit, which is derived from the compound represented by Structural Formula A that is prepared according to Preparation Example 1 and applied in the following examples and comparative example, and a structural unit derived from pentafluorostyrene. In FIG. 8, the part that is marked as e and the part that is marked as d refer to the peaks that come from the block 2 (that is, the aforementioned structural unit that is derived from pentafluorostyrene), and the rest (a, b, c, f, g, h, i and j) are the peaks that come from a structural unit that is derived from the compound (represented by Structural Formula A) of Preparation Example 1. As can be seen in the graph, the peaks marked as e and g and the peaks marked as d and f overlap each other; in which case, the overlapping of the peaks should be taken into consideration when obtaining the value of K.

[0097] In this case, the method of obtaining the value of K by taking the overlapping of the peaks into account is well known in the art; the value can be obtained, for example, by using an NMR interpretation program such as MestReC program.

Preparation Example 1. Synthesis of Monomer A

[0098] The compound (DPM-C12) represented by the following Structural Formula A was synthesized by the following method: hydroquinone (10.0 g, 94.2 mmol) and 1-bromododecane (23.5 g, 94.2 mmol) were introduced into a 250-mL flask, dissolved in 100 mL of acetonitrile; then, an excessive amount of potassium carbonate was added to the above solution and allowed to react at about 75° C. for about 48 hours under a nitrogen atmosphere; upon completion of the reaction, the reaction products were filtered to be removed of the remaining potassium carbonate and acetonitrile that was used for the reaction; then the substances were worked up through an addition of a mixed solvent of dichloromethane (DCM) and water, and the separated organic layer was collected and dehydrated with MgSO.sub.4; subsequently, the substances were purified by column chromatography (CC) with DCM to obtain a white solid target material (i.e. 4-(dodecyloxy)-phenol) with a yield of about 37%.

[0099] <NMR Analysis Results>

[0100] .sup.1H-NMR (CDCl.sub.3): δ6.77 (dd, 4H); δ4.45 (s, 1H); δ3.89 (t, 2H); δ4.75 (p, 2H); δ4.43 (p, 2H); δ4.33-1.26 (m, 16H); δ0.88 (t, 3H).

[0101] The synthesized 4-(dodecyloxy)-phenol (9.8 g, 35.2 mmol), methacrylic acid (6.0 g, 69.7 mmol), dicyclohexylcarbodiimide (DCC) (10.8 g, 52.3 mmol) and p-dimethylaminopyridine (DMAP) (1.7 g, 13.9 mmol) were introduced into a flask, 120 mL of methylene chloride was added, and then allowed to react at room temperature for 24 hours under a nitrogen atmosphere; upon completion of the reaction, the reaction products were filtered to be removed of a urea salt that was produced during the reaction and also of the remaining methylene chloride; then, the substances were removed of impurities by column chromatography (CC) that uses hexane and dichloromethane (DCM) as the mobile phase, the obtained products were recrystallized in a mixed solvent of methanol and water (mixed in a weight ratio of 1:1) to obtain a white solid target material (7.7 g, 22.2 mmol) with a yield of 63%.

[0102] <NMR Analysis Results>

[0103] .sup.1H-NMR (CDCl.sub.3): δ7.02 (dd, 2H); δ6.89 (dd, 2H); δ6.32 (dt, 1H); δ5.73 (dt, 1H); δ3.94 (t, 2H); δ2.05 (dd, 3H); δ4.76 (p, 2H); δ4.43 (p, 2H); 1.34-1.27 (m, 16H); δ0.88 (t, 3H).

##STR00005##

[0104] In Structural Formula A, R represents a linear-chain alkyl group with 12 carbons.

Example 1

[0105] 5.0 g of monomer A of Preparation Example 1, 165 mg of a reversible addition-fragmentation chain transfer (RAFT) reagent (cyanoisopropyl dithiobenzoate), 79 mg of a radical initiator (azobisisobutyronitrile, AIBN) and 11.9 mL of anisole were introduced into a 25-mL Schlenk flask, stirred at room temperature for 30 minutes under a nitrogen atmosphere, and then a RAFT polymerization reaction was carried out at 70° C. for 4 hours. Upon completion of the polymerization, the reaction solution was precipitated in 250 mL of an extraction solvent (methanol) and then dried by filtration under reduced pressure to prepare a pink macroinitiator. The yield of the macroinitiator was about 57.0 wt %, and the number average molecular weight (Mn) and molecular weight distribution (Mw/Mn) were 10300 and 1.21, respectively.

[0106] 0.35 g of the above macroinitiator, 3.2 g of pentafluorostyrene (the monomer that constitutes the block 2) and 1.2 mL of anisole were introduced into a 10-mL Schlenk flask, stirred at room temperature for 30 minutes under a nitrogen atmosphere, and then a RAFT polymerization reaction was carried out at 115° C. for 4 hours. Upon completion of the polymerization, the reaction solution was precipitated in 250 mL of an extraction solvent (methanol) and then dried by filtration under reduced pressure to prepare a light-pink block copolymer. The yield of the block copolymer was about 13 wt %, and the Mn and Mw/Mn were 15,600 and 1.15, respectively. The above block copolymer contains the block 1 (that is derived from monomer A prepared according to Preparation Example 1) and the block 2 (that is derived from the aforementioned pentafluorostyrene monomer). The results of .sup.1H-NMR analysis on the block copolymer that was prepared according to Example 1 are provided in FIG. 1.

Example 2

[0107] 5.0 g of monomer A of Preparation Example 1, 106.5 mg of a reversible addition-fragmentation chain transfer (RAFT) reagent (cyanoisopropyl dithiobenzoate), 79 mg of a radical initiator (azobisisobutyronitrile, AIBN) and 11.9 mL of anisole were introduced into a 25-mL Schlenk flask, stirred at room temperature for 30 minutes under a nitrogen atmosphere, and then a RAFT polymerization reaction was carried out at 70° C. for 4 hours. Upon completion of the polymerization, the reaction solution was precipitated in 250 mL of an extraction solvent (methanol) and then dried by filtration under reduced pressure to prepare a pink macroinitiator. The yield of the macroinitiator was about 57.0 wt %, and the number average molecular weight (Mn) and molecular weight distribution (Mw/Mn) were 10,400 and 1.19, respectively. 0.3 g of the macroinitiator, 3.3 g of a pentafluorostyrene monomer and 1.2 mL of benzene were introduced into a 10-mL Schlenk flask, stirred at room temperature for 30 minutes under a nitrogen atmosphere, and then a RAFT polymerization reaction was carried out at 115° C. for 4 hours. Upon completion of the polymerization, the reaction solution was precipitated in 250 mL of an extraction solvent (methanol) and then dried by filtration under reduced pressure to prepare a light-pink block copolymer. The yield of the block copolymer was about 18 wt %, and the Mn and Mw/Mn were 17,800 and 1.14, respectively. The above block copolymer contains the block 1 (that is derived from monomer A prepared according to Preparation Example 1) and the block 2 (that is derived from the aforementioned pentafluorostyrene monomer). The results of .sup.1H-NMR analysis on the block copolymer that was prepared according to Example 2 are provided in FIG. 2.

Example 3

[0108] 5.0 g of monomer A of Preparation Example 1, 456 mg of a reversible addition-fragmentation chain transfer (RAFT) reagent (cyanoisopropyl dithiobenzoate), 34 mg of a radical initiator (azobisisobutyronitrile, AIBN) and 12.8 mL of anisole were introduced into a 25-mL Schlenk flask, stirred at room temperature for 30 minutes under a nitrogen atmosphere, and then a RAFT polymerization reaction was carried out at 70° C. for 4 hours. Upon completion of the polymerization, the reaction solution was precipitated in 250 mL of an extraction solvent (methanol) and then dried by filtration under reduced pressure to prepare a pink macroinitiator. The yield of the macroinitiator was about 60.0 wt %, and the number average molecular weight (Mn) and molecular weight distribution (Mw/Mn) were 5,700 and 1.18, respectively. 0.2 g of the macroinitiator, 3.4 g of a pentafluorostyrene monomer and 1.2 mL of anisole were introduced into a 10-mL Schlenk flask, stirred at room temperature for 30 minutes under a nitrogen atmosphere, and then a RAFT polymerization reaction was carried out at 115° C. for 15 hours. Upon completion of the polymerization, the reaction solution was precipitated in 250 mL of an extraction solvent (methanol) and then dried by filtration under reduced pressure to prepare a light-pink block copolymer. The yield of the block copolymer was about 16 wt %, and the Mn and Mw/Mn were 59,000 and 1.22, respectively. The above block copolymer contains the block 1 (that is derived from monomer A prepared according to Preparation Example 1) and the block 2 (that is derived from the aforementioned pentafluorostyrene monomer). The results of .sup.1H-NMR analysis on the block copolymer that was prepared according to Example 3 are provided in FIG. 3.

Comparative Example 1

[0109] 5.0 g of monomer A of Preparation Example 1, 106.5 mg of a reversible addition-fragmentation chain transfer (RAFT) reagent (cyanoisopropyl dithiobenzoate), 79 mg of a radical initiator (azobisisobutyronitrile, AIBN) and 11.9 mL of anisole were introduced into a 25-mL Schlenk flask, stirred at room temperature for 30 minutes under a nitrogen atmosphere, and then a RAFT polymerization reaction was carried out at 70° C. for 4 hours. Upon completion of the polymerization, the reaction solution was precipitated in 250 mL of an extraction solvent (methanol) and then dried by filtration under reduced pressure to prepare a yellow macroinitiator. The yield of the macroinitiator was about 52.0 wt %, and the number average molecular weight (Mn) and molecular weight distribution (Mw/Mn) were 9,100 and 1.20, respectively. 0.5 g of the macroinitiator, 4.5 g of a pentafluorostyrene monomer and 1.7 mL of anisole were introduced into a 10-mL Schlenk flask, stirred at room temperature for 30 minutes under a nitrogen atmosphere, and then a RAFT polymerization reaction was carried out at 115° C. for 4 hours. Upon completion of the polymerization, the reaction solution was precipitated in 250 mL of an extraction solvent (methanol) and then dried by filtration under reduced pressure to prepare a light-yellow block copolymer. The yield of the block copolymer was about 15 wt %, and the Mn and Mw/Mn were 23,200 and 1.12, respectively. The above block copolymer contains the block 1 (that is derived from monomer A prepared according to Preparation Example 1) and the block 2 (that is derived from the aforementioned pentafluorostyrene monomer). The results of .sup.1H-NMR analysis on the block copolymer that was prepared according to Comparative Example 1 are provided in FIG. 4.

[0110] The measured results of GPC on each of the macroinitiators and block copolymers prepared according to the examples and comparative example are summarized and provided in Table 1 below, and each of the values of X of block copolymers prepared according to Examples 1 to 3 and Comparative Example 1 are summarized and provided in Table 2 below.

TABLE-US-00001 TABLE 1 Examples Comparative Example 1 2 3 1 MI Mn 10300 10400 5700 9100 PDI 1.21 1.19 1.18 1.20 BCP Mn 15600 17800 59000 23200 PDI 1.15 1.14 1.22 1.12 MI: macroinitiator BCP: block copolymer Mn: number average molecular weight PDI: molecular weight distribution

TABLE-US-00002 TABLE 2 Comparative Example 1 Example 2 Example 3 Example 1 X value 4   about 3.2 about 1.18 2   D 1.57 1.57 1.57 1.57 M about 1.79 about 1.79 about 1.79 about 1.79 K about 0.08 about 0.11 about 1.37 about 0.25 L about 11.3 about 11.3 about 11.3 about 11.3 D: ratio (D2/D1) of density (D2) of block 2 to density (D1) of block 1 M: ratio (M1/M2) of molar mass (346.5 g/mol, M1) of monomer A of Preparation Example 1 (as monomer that constitutes block 1) to molar mass (194.1 g/mol, M2) of pentafluorostyrene (as monomer that constitutes block 2) K: ratio (A2/A1) of area (A2) of peak in .sup.1H-NMR produced based on block 2 to area (A1) of peak produced based on block 1 L: ratio (H1/H2) of number (34, H1) of hydrogen atoms in monomer A of Preparation Example 1 (as monomer that constitutes block 1) to number (3, H2) of hydrogen atoms in pentafluorostyrene (as monomer that constitutes block 2)

Test Example 1. Evaluation of Self-Assembling Property

[0111] The coating solution prepared by dissolving the block copolymer of an example or comparative example in fluorobenzene to a solid concentration of 0.7 wt % was spin-coated (coating area: width×length=1.5 cm×1.5 cm) on a silicon wafer to a thickness of about 5 nm, dried at room temperature for about 1 hour, and then thermal-annealed at a temperature of about 160° C. for about 1 hour to form a self-assembled film. A scanning electron microscopic (SEM) image was taken of the film. FIG. 5 is an AFM image of Example 1, and FIG. 6 is an SEM image of Example 2. As seen in the images, a polymer film with a cylindrical structure was effectively formed with the block copolymer of Example, and a polymer film with a cylindrical structure was also observed with Example 3. In contrast, phase separation sufficient for the formation of a cylindrical structure was not induced with Comparative Example 1. FIG. 7 is the result of SEM of Comparative Example 1, from which a failure to induce effective phase separation into a cylindrical structure can be identified.