Method for producing a polymer film by using a polymer composition

Abstract

The present disclosure relates to a polymer composition and a use thereof to produce a polymer film. Such a polymer composition provides excellent self-assembly properties and is capable of forming a vertical orientation structure in a short time even on a surface where no neutral treatment is performed.

Claims

1. A method for producing a polymer film comprising forming a polymer film using a polymer composition comprising block copolymers, and inducing a cylinder structure of the block copolymers in the polymer film, wherein the block copolymers comprise a first block copolymer, and a second block copolymer having a number average molecular weight different from that of the first block copolymer, wherein both the first block copolymer and the second block copolymer have a polymer segment A and a polymer segment B, wherein the polymer segment A comprises a ring structure and a side chain having 8 or more chain-forming atoms, wherein the side chain is substituted on the ring structure via linker selected from an oxygen atom, a sulfur atom, NR.sub.1, S(O).sub.2, a carbonyl group, an alkylene group, an alkenylene group, an alkynylene group, C(O)X.sub.1 or X.sub.1C(O), wherein R.sub.1 is hydrogen, an alkyl group, an alkenyl group, an alkynyl group, an alkoxy group or an aryl group, and X.sub.1 is a single bond, an oxygen atom, a sulfur atom, NR.sub.2, S(O).sub.2, an alkylene group, an alkenylene group or an alkynylene group, where R.sub.2 is hydrogen, an alkyl group, an alkenyl group, an alkynyl group, an alkoxy group or an aryl group, and wherein the polymer segment B comprises a ring structure wherein three or more halogen atoms are substituted on the ring structure.

2. The method for producing a polymer film according to claim 1, wherein the first block copolymer of the block copolymers in the polymer composition has the smallest number average molecular weight (M1) and the number average molecular weight (M1) is in a range of 5 to 60 Kg/mol.

3. The method for producing a polymer film according to claim 2, wherein the weight ratio of the first block copolymer based on the total weight of the block copolymers in the polymer composition is in a range of 10 wt % to 90 wt %.

4. The method for producing a polymer film according to claim 2, wherein the molar ratio of the first block copolymer based on the total mole number of the block copolymers in the polymer composition is in a range of 10 mol % to 90 mol %.

5. The method for producing a polymer film according to claim 1, wherein the second block copolymer of the block copolymers in the polymer composition has the largest number average molecular weight (M2) and the number average molecular weight (M2) is in a range of 10 to 100 Kg/mol.

6. The method for producing a polymer film according to claim 5, wherein the weight ratio of the second block copolymer based on the total weight of the block copolymers in the polymer composition is in a range of 10 wt % to 90 wt %.

7. The method for producing a polymer film according to claim 5, wherein the molar ratio of the second block copolymer based on the total mole number of the block copolymers in the polymer composition is in a range of 10 mol % to 90 mol %.

8. The method for producing a polymer film according to claim 1, wherein the ratio (M2/M1) of the number average molecular weight (M2) of the second block copolymer to the number average molecular weight (M1) of the first block copolymer is in a range of 1.2 to 10.

9. The method for producing a polymer film according to claim 1, wherein the difference (M2-M1) between the number average molecular weight (M1) of the first block copolymer and the number average molecular weight (M2) of the second block copolymer is 100 Kg/mol or less.

10. The method for producing a polymer film according to claim 1, wherein the polymer segment A satisfies any one condition of Conditions 1 to 3 below: Condition 1: it exhibits a melting transition peak or an isotropic transition peak in a range of 80 C. to 200 C. in a differential scanning calorimetry (DSC) analysis: Condition 2: it exhibits a peak having a half-value width in a range of 0.2 to 0.9 nm.sup.1 within a scattering vector (q) range of 0.5 nm.sup.1 to 10 nm.sup.1 in an X-ray diffraction (XRD) analysis: Condition 3: it comprises a side chain, which satisfies Equation 1 below:
3 nm.sup.1 to 5 nm.sup.1=nq/(2)[Equation 1] wherein, n is a number of chain-forming atoms in the side chain and q is the smallest scattering vector in which a peak is observed in the XRD analysis for the block copolymer or the scattering vector in which a peak of the largest peak area is observed.

11. The method for producing a polymer film according to claim 10, wherein the absolute value of the difference in surface energy between the polymer segments A and B is in a range of 2.5 to 7 mN/m.

12. The method for producing a polymer film according to claim 1, wherein the sum of volume fractions of the polymer segment A in the polymer composition is in a range of 0.5 to 0.7, and the sum of volume fractions of the polymer segment A and the polymer segment B in the polymer composition is 1.

13. The method for producing a polymer film according to claim 1, wherein the chain-forming atoms are each independently a carbon, an oxygen, a sulfur or a nitrogen atom.

Description

BRIEF DESCRIPTION OF DRAWINGS

(1) The FIGURE is an SEM photograph of the polymer film of Example 1.

MODE FOR INVENTION

(2) Hereinafter, the present application will be described in detail by way of examples according to the present application and comparative examples, but the scope of the present application is not limited by the following examples.

(3) 1. NMR Measurement

(4) NMR analyses were performed at room temperature using an NMR spectrometer including a Varian Unity Inova (500 MHz) spectrometer with a triple resonance 5 mm probe. The analytes were diluted in a solvent for NMR measurement (CDCl.sub.3) to a concentration of about 10 mg/ml, and chemical shifts were expressed in ppm.

(5) <Application Abbreviation>

(6) br=broad signal, s=singlet, d=doublet, dd=double doublet, t=triplet, dt=double triplet, q=quartet, p=quintet, m=multiplet.

(7) 2. GPC (Gel Permeation Chromatograph)

(8) The number average molecular weight (Mn) and the molecular weight distribution were measured using GPC (gel permeation chromatography). Into a 5 mL vial, an analyte such as block copolymers of Examples or Comparative Examples or a giant initiator is put and diluted in THF (tetrahydrofuran) to be a concentration of about 1 mg/mL or so. Then, a standard sample for calibration and a sample to be analyzed were filtered through a syringe filter (pore size: 0.45 m) and then measured. As the analytical program, ChemStation from Agilent Technologies was used, and the elution time of the sample was compared with the calibration curve to obtain the weight average molecular weight (Mw) and the number average molecular weight (Mn), respectively, and the molecular weight distribution (PDI) was calculated by the ratio (Mw/Mn) thereof. The measurement conditions of GPC are as follows.

(9) <GPC Measurement Condition>

(10) Instrument: 1200 series from Agilent Technologies

(11) Column: using two PLgel mixed B from Polymer Laboratories

(12) Solvent: THF

(13) Column temperature: 35 C.

(14) Sample concentration: 1 mg/mL, 200 L injection

(15) Standard samples: polystyrene (Mp: 3900000, 723000, 316500, 52200, 31400, 7200, 3940, 485)

(16) 3. XRD Analysis Method

(17) The XRD analysis was performed by transmitting X rays to a sample at a Pohang accelerator 4C beamline to measure the scattering intensity according to the scattering vector (q). As the sample, a block copolymer in a powder state dried by purifying a synthesized block copolymer without special pretreatment and then maintaining it in a vacuum oven for one day or so, was placed in a cell for XRD measurement and used. Upon the XRD pattern analysis, an X-ray with a vertical size of 0.023 mm and a horizontal size of 0.3 mm was used and a 2D marCCD was used as a detector. A 2D diffraction pattern scattered and exited was obtained as an image. The obtained diffraction pattern was analyzed by a numerical analytical method to which a least-square method was applied to obtain information such as a scattering vector and a half-height width. Upon the analysis, an origin program was applied, and the profile of the XRD patterns was subjected to Gaussian fitting in a state where a portion showing the smallest intensity in the XRD diffraction patterns was taken as a baseline and the intensity in the above was set to zero, and then the scattering vector and the half-height width were obtained from the fitted results. Upon Gaussian fitting, the R square was at least set to be 0.96 or more.

(18) 4. Measurement of Surface Energy

(19) The surface energy was measured using a drop shape analyzer (DSA100 product from KRUSS). A coating liquid was prepared by diluting the substance (polymer), which is measured, in fluorobenzene to a solid concentration of about 2 wt %, and the prepared coating liquid was spin-coated on a silicon wafer to a thickness of about 50 nm and a coating area of 4 cm.sup.2 (width: 2 cm, height: 2 cm). The coating layer was dried at room temperature for about 1 hour and then subjected to thermal annealing at about 160 C. for about 1 hour. The process of dropping the deionized water whose surface tension was known on the film subjected to thermal annealing and obtaining the contact angle thereof was repeated five times to obtain an average value of the obtained five contact angle values. In the same manner, the process of dropping the diiodomethane whose surface tension was known thereon and obtaining the contact angle thereof was repeated five times to obtain an average value of the obtained five contact angle values. The surface energy was obtained by substituting the value (Strom value) regarding the solvent surface tension by the Owens-Wendt-Rabel-Kaelble method using the obtained average values of the contact angles for the deionized water and diiodomethane. The numerical value of the surface energy for each polymer segment of the block copolymer was obtained for a homopolymer made of only the monomer forming the polymer segment by the above-described method.

(20) 5. Measurement of Volume Fraction

(21) The volume fraction of each polymer segment of the block copolymer was calculated based on the density of each polymer segment at room temperature and the molecular weight measured by GPC. Here, the density was measured using a buoyancy method, and specifically, it was calculated by placing a sample to be analyzed in a solvent (ethanol) to know the mass and density in air, and measuring the mass.

Preparation Example 1. Synthesis of Monomer (A)

(22) A compound (DPM-C12) of Formula A below was synthesized in the following manner. Hydroquinone (10.0 g, 94.2 mmol) and 1-bromododecane (23.5 g, 94.2 mmol) were placed in a 250 mL flask, dissolved in 100 mL of acetonitrile, and then an excess amount of potassium carbonate was added thereto and reacted at 75 C. for about 48 hours under a nitrogen condition. After the reaction, the remaining potassium carbonate was filtered off and the acetonitrile used in the reaction was also removed. A mixed solvent of DCM (dichloromethane) and water was added thereto to work up the mixture, and the separated organic layers were collected and passed through MgSO.sub.4 to be dehydrated. Subsequently, the target product (4-dodecyloxyphenol) (9.8 g, 35.2 mmol) in a white solid phase was obtained in a yield of about 37% using DCM (dichloromethane) in column chromatography.

(23) <NMR Analysis Result>

(24) .sup.1H-NMR (CDCl.sub.3): d6.77 (dd, 4H); d4.45 (s, 1H); d3.89 (t, 2H); d1.75 (p, 2H); d1.43 (p, 2H); d1.33-1.26 (m, 16H); d0.88 (t, 3H).

(25) The synthesized 4-docecyloxyphenol (9.8 g, 35.2 mmol), methacrylic acid (6.0 g, 69.7 mmol), DCC (dicyclohexylcarbodiimide) (10.8 g, 52.3 mmol) and DMAP (p-dimethylaminopyridine) (1.7 g, 13.9 mmol) were placed in the flask and 120 mL of methylene chloride was added thereto, and then reacted at room temperature for 24 hours under nitrogen. After completion of the reaction, the salt (urea salt) generated during the reaction was filtered off and the remaining methylene chloride was also removed. Impurities were removed using hexane and DCM (dichloromethane) as the mobile phase in column chromatography and the product obtained again was recrystallized in a mixed solvent of methanol and water (1:1 mix) to obtain the target product (7.7 g, 22.2 mmol) in a white solid phase in a yield of 63%.

(26) <NMR Analysis Result>

(27) .sup.1H-NMR (CDCl.sub.3): d7.02 (dd, 2H); d6.89 (dd, 2H); d6.32 (dt, 1H); d5.73 (dt, 1H); d3.94 (t, 2H); d 2.05 (dd, 3H); d1.76 (p, 2H); d1.43 (p, 2H); 1.34-1.27 (m, 16H); d0.88 (t, 3H).

(28) ##STR00005##

(29) In Formula A, R is a linear alkyl group having 12 carbon atoms.

Preparation Example 2. Synthesis of Block Copolymer (A)

(30) 4.0 g of the monomer (A) of Preparation Example 1, 64 mg of cyanoisoproyl dithiobenzoate as an RAFT (reversible addition-fragmentation chain transfer) reagent, 23 mg of AIBN (azobisisobutyronitrile) as a radical initiator and 5.34 mL of benzene were placed in a 10 mL Schlenk flask and stirred at room temperature for 30 minutes under a nitrogen atmosphere, and then an RAFT (reversible addition-fragmentation chain transfer) polymerization reaction was performed at 70 C. for 4 hours. After the polymerization, the reaction solution was precipitated in 250 mL of methanol as an extraction solvent, and then filtered under reduced pressure and dried to prepare a pink macro initiator. The number average molecular weight (Mn) and the molecular weight distribution (Mw/Mn) of the macro initiator were 18,000 g/mol and 1.15, respectively.

(31) 0.3 g of the macro initiator, 5 g of a pentafluorostyrene monomer and 5 mL of benzene were placed in a 50 mL Schlenk flask and stirred at room temperature for 30 minutes under a nitrogen atmosphere, and then an RAFT (reversible addition-fragmentation chain transfer) polymerization reaction was performed at 115 C. for 4 hours. After the polymerization, the reaction solution was precipitated in 500 mL of methanol as an extraction solvent, and then filtered under reduced pressure and dried to prepare a pale pink block copolymer. The yield of the block copolymer was about 18 wt %, and the number average molecular weight (Mn) and the molecular weight distribution (Mw/Mn) were 40,000 g/mol and 1.11, respectively. The block copolymer comprises a polymer segment A derived from the monomer (A) of Preparation Example 1 and a polymer segment B derived from the pentafluorostyrene monomer.

Preparation Examples 3 to 7

(32) Five kinds of block copolymers having different molecular weights were further prepared in the same manner as in Preparation Example 2 except for controlling the molar ratios of the monomer and the macro initiator, and the like. The characteristics of the macro initiator and the block copolymer used in each preparing process were summarized and described in Table 1 below.

(33) TABLE-US-00001 TABLE 1 Preparation Example 2 3 4 5 6 7 Block copolymer A B C D E F Macro Molecular 18 29 29 14 9 8 initiator weight (Mn) Molecular weight 1.15 1.19 1.11 1.19 1.14 1.10 distribution Block Molecular 40 53 73 30 19 21 copolymer weight (Mn) Molecular weight 1.11 1.15 1.15 1.22 1.20 1.12 distribution Volume fraction 0.44 0.34 0.49 0.42 0.42 0.53 Molecular weight (Mn): number average molecular weight (unit: Kg/mol) Molecular weight distribution (Mw/Mn): ratio (Mw/Mn) of weight average molecular weight (Mw) to number average molecular weight (Mn) Volume fraction: volume fraction of polymer segment B (the total volume fraction of segments A and B is 1)

(34) The block copolymers (A) to (D) prepared above all contain a side chain having 12 chain-forming atoms in the segment A (the R moiety of Formula A above). Furthermore, for each block copolymer, the value of n/D, that is, the numerical value calculated by nq/(2) in Equation 1 above (in Equation 1 above, n is the number of chain-forming atoms (12), q is the scattering vector value at which the peak with the largest peak area is identified in the scattering vector range of 5 nm.sup.1 to 10 nm.sup.1 the XRD analysis) was about 3.75 for all, the surface energy of the polymer segment A was about 30.83 mN/m in all the five block copolymers, and the surface energy of the polymer segment B was also about 24.4 mN/m in all the five block copolymers. In addition, the density of the polymer segment A was about 1 g/cm.sup.3 in all the five block copolymers, and the density of the polymer segment B was about 1.57 g/cm.sup.3.

Example 1

(35) The block copolymer (A) of Preparation Example 2 and the block copolymer (E) of Preparation Example 6 were mixed to prepare a polymer composition. The specific compositions in the polymer composition were summarized and described in Table 2 below. Subsequently, a coating liquid prepared by diluting the polymer composition in toluene to a solid concentration of about 1.5 wt % was spin-coated on a substrate, dried at room temperature for about 1 hour, and then thermally annealed at a temperature of about 200 C. for about 10 minutes to form a self-assembled film. Here, as the substrate, a known silicon wafer without any neutral treatment on its surface was applied. An SEM (scanning electron microscope) image of the formed film was photographed. The FIGURE is an SEM image photographed in Example 1, and as confirmed from the drawing, it was confirmed that in the case of the polymer composition of Example 1, the vertically oriented self-assembled cylinder structure was effectively formed.

Examples 2 to 5 and Comparative Example 1

(36) Polymer films were formed in the same manner as in Example 1, except that the types and ratios of the block copolymers applied upon preparing the polymer composition were changed as in Table 2 below, and the evaluation results thereof were summarized and described in Table 2 below.

(37) TABLE-US-00002 TABLE 2 Comparative Example Example 1 2 3 4 5 1 Polymer Fisrt BCP A B C B C C composition Second BCP E E E F D Third BCP E Weight ratio 1:1 1:1 1:1 1:1 2:1:1 Molar ratio 1:2.1 1:2.8 1:3.8 1:2.6 1:1.2:2.0 1 VF 0.43 0.36 0.46 0.42 0.35 0.49 Phase formed formed formed formed formed unformed separation Pitch 30 nm 35 nm 42 nm 37 nm 45 nm First BCP: type of first block copolymer Second BCP: type of second block copolymer Third BCP: type of third block copolymer Weight ratio: weight ratio of block copolymers (first BCP: second BCP or first BCP: second BCP: third BCP) Molar ratio: molar ratio of block copolymers (first BCP: second BCP or first BCP: second BCP: third BCP) VF: sum of polymer segments B in the polymer composition (based on 1 of the sum of polymer segments A and B) Phase separation: whether or not a vertically oriented cylinder structure is formed in the same form as in Figure 1 of Example 1 (in the case of Comparative Example 1, a horizontal orientation lamellar structure is formed) Pitch: distance between cylinder centers in vertically oriented cylinder structure (unit: nm)