WO2007055041A1

WO2007055041A1 - Membrane of block copolymer with oriented cylinder structure and process for producing the same

Info

Publication number: WO2007055041A1
Application number: PCT/JP2006/309321
Authority: WO
Inventors: Shinichi Sakurai; Yoshihiro Tsuji; Tsunehisa Kimura; Masafumi Yamato; Fumiko Kimura
Original assignee: National University Corporation Kyoto Institute Of Technology; Tokyo Metropolitan University; Independent Administrative Institution National Institute For Materials Science
Priority date: 2005-11-10
Filing date: 2006-05-09
Publication date: 2007-05-18

Abstract

A process for producing a membrane of block copolymer with cylinder structure oriented in a given single direction. There is provided a membrane of block copolymer with cylinder structure having a membrane thickness of 10 nm to 50 μm and oriented in a given single direction, preferably exhibiting an absolute value of turbulence of orientation angle against orientation direction, regulated by the dependence on orientation angle of reflection spot strength according to glancing angle incidence small-angle X-ray scattering measurement, of 40° or less. Further, there is provided a process for producing the membrane of block copolymer with cylinder structure.

Description

Specification

Block copolymer film having oriented cylinder structure and method for producing the same

Technical field

[0001] This patent application is based on Japanese Patent Application No. 2005-326221 (filed on Nov. 10, 2005, the name of the invention "block copolymer film having an oriented cylinder structure and its manufacturing method"). The priority of the Paris Convention is claimed, and the content described in the above application is incorporated herein by reference.

The present invention relates to a block copolymer film having an oriented cylinder structure. Specifically, the present invention relates to a block copolymer film having a cylinder structure oriented in one predetermined direction, particularly in one direction parallel to the film surface, and a method for producing the same.

Background art

[0002] A technology that imparts a fine structure to a material and uses its unique functions and physical properties is generally referred to as nanotechnology. In recent years, it has been applied not only to the electronics field but also to a wide range of fields such as energy and the environment. Expected!

As materials that can be applied to the manufacture of magnetic recording media, solar cells, light-emitting elements, precision filters, etc. by forming nanometer-order patterns on a substrate in a self-organized manner, aromatic ring-containing polymer chains and acrylic polymers A pattern material containing a block copolymer or a graft copolymer having a chain and forming a microphase-separated structure is known (Patent Document 2). However, a technique for freely controlling the orientation direction of the cylinder structure is not studied, but, for example, in Patent Document 1, a spherical microphase separation structure is packed in a hexagonal close-packed state in a thin film having a thickness of about the diameter of a sphere. It is just a disclosure of the applied technology of the phenomenon (self-organization ability).

Patent Document 1: Japanese Patent Laid-Open No. 2001-151834

Patent Document 2: Japanese Patent Laid-Open No. 2002-279616

[0003] On the other hand, Non-Patent Documents 1 and 2 disclose a method of orienting a lamella cylinder in a diblock copolymer or a triblock copolymer in parallel to the film surface using a flow field. However, these methods cannot form fine streaks on the surface of the block copolymer film.

Non-Patent Document 1: Spherulite formation rrom microphase- separated lamellae in semi-cry stalline diblock copolymer comprising polyethylene and atactic polypropylene blocks; M. Ueda, K. Sakurai, S. Okamoto, DJ Lohse, WJ MacKnight, S. Shinkai, S. S akurai, S. Nomura (2003, Polymer, 44, pp. 6995-7005)

Non-Patent Document 2: "Synchrotron Small-Angle X-ray Scattering Studies on Flow-Induced

Gyroid to Cylinder Transition in an Elastomeric SBS Triblock Copolymer〃; S. Sakur ai, T. Kota, D. Isobe, S. Okamoto, K. Sakurai, T. Ono, K. Imaizumi, S. Nomura (20

04, J. Macromol. Sci "Physics, B43, pp. 1-11)

[0004] Also, a block copolymer film having a vertically aligned lamella structure is produced by placing a block copolymer resin on a substrate having a predetermined characteristic surface roughness or higher and heat-treating the resin. The method is also known (Patent Document 3).

Patent Document 3: Japanese Patent Laid-Open No. 2004-99667

[0005] However, the method described in Patent Document 3 is a method of orienting the lamella structure perpendicularly to the film surface, and has the disadvantage that the arrangement of the lamella structure in the obtained film surface cannot be defined. It was. In addition, as in the case of a cylinder structure, there is an inconvenience that it can hardly be applied to create nanopores (micropores) by post-processing.

In view of this, studies have been conducted to provide a vertically aligned cylinder structure as follows.

[0006] For example, when a polystyrene-polymethyl methacrylate diblock copolymer film is cast on an electrode plate and a DC voltage of 30 to 40 ¥ 7 111 is applied for 14 hours at 165 °, it becomes polymethyl methacrylate. It has been reported that the cylinder is vertically aligned (Non-patent Document 3). However, since the obtained diblock copolymer film has a very thin film thickness: L m or less, its utility value as a material was small. In addition, according to this method, a complicated process of applying an electric field is required, and this method cannot be applied to a polymer that does not respond to an electric field.

Special Reference 3: Ultrahigh— Density Nanowire Arravs Grown in ¾elf— Assembled Diblock Copolymer Templates, T. Thurn— Albrecht, J. Schotter, GA Kaestle, N. Emley, T. Shibauchi, L. Krusin— Elbaum, K. Guarini, CT Black, MT Tuominen, and TP Russell, Science Dec 15 2000: 2126 -2129

[0007] Also, after grafting a random copolymer of styrene-methyl methacrylate, a method of casting a polystyrene-polymethyl methacrylate diblock copolymer to form a cylinder structure standing perpendicular to the surface Is also known (Non-Patent Document 4). However, this method is not only complicated, but the resulting diblock copolymer film is extremely thin with a film thickness of 30 nm or less, and thus has a low utility value as a material. In addition, although the cylinders were vertically oriented, the arrangement (arrangement of the circular cross section of the cylinder) when viewed in the film plane was random.

Non-Patent Document 4: K. Shin, K. A. Leach, J. T. Goldbach, D. H. Kim, J. Y. Jho, M. Tuom inen, C. J. Hawker, T. P. Russell, Nano Letters, 2, 933 (2002)

[0008] In addition, it has been proposed to prepare a vertically aligned mesoporous silica film by using a novel polysilicate as an intermediate (Patent Document 4). However, in the case of such a material, it is difficult to dissolve it in an organic solvent or to thermally decompose it, so that it is not suitable for a vertical application such as a nano template.

Patent Document 4: Japanese Unexamined Patent Publication No. 2003-335516

[0009] In addition, in order to obtain a microphase-separated structure film with a uniform orientation, the molecular weight distribution (Mw) of each polymer component in the block copolymer consisting of a hydrophilic polymer component (A) and a hydrophobic polymer component (B) A method for adjusting / Mn) to 1.3 or less has been proposed (Patent Document 5).

However, this method has the disadvantage that the cylinder structure can be oriented in the direction perpendicular to the film surface, but cannot be oriented freely in the parallel direction or other directions.

Patent Document 5: Japanese Unexamined Patent Application Publication No. 2004-124088

[0010] The inventors of the present invention used a predetermined styrene ethylene butylene styrene triblock copolymer to form a spherical microphase separation structure by a solution casting method using a selective solvent, and this was formed at a temperature of 150 ° C. A method of time heat treatment was proposed (Non-Patent Document 5). Same document Discloses that a transition from a spherical shape to a cylindrical microphase-separated structure is caused by the heat treatment. When the spheres coalesce to form a cylinder, the cylinder is oriented perpendicular to the film surface. A method for producing a vertically-oriented cylinder material using the property is disclosed.

However, in this method, the cylinder structure can be oriented in a direction perpendicular to the film surface, but cannot be easily oriented in a parallel direction.

Non-Patent Document 5: Influence of Microphase Separation Structure on Mechanical Properties of Styrene-Ethylene Butylene-Styrene Triblock Copolymer Films ”; Hideo Hamada, Sakae Aida, Shinichi Sakurai, Yutaka Kitagawa, Yoshikazu Suda, Junzo Masamoto , Haruji Nomura (1997, Journal of Japanese Society of Rheology, Vol. 25, pp. 217-220)

[0011] On the other hand, it is known that a microcrystalline region in a crystalline polymer material can be oriented by applying a magnetic field, and magnetic processing of a crystalline polymer material using this property has been proposed. (Patent Document 6). However, it has been shown that in order to produce a magnetic torque large enough to enable magnetic field orientation, the microcrystalline region must grow to a size on the order of submicron, In such a high molecular weight material, a domain that enables such a magnetic field orientation is not formed. Therefore, the use of a magnetic field has not been studied.

Patent Document 6: Japanese Patent Laid-Open No. 2005-68249

[0012] Further, a method is known in which a block copolymer is oriented in a thin film by rapid solidification to form a vertical cylinder structure or the like (Patent Document 7). However, the method described in this document cannot form streak irregularities on the film surface.

Patent Document 7: US Patent No. 6893705

Disclosure of the invention

Problems to be solved by the invention

[0013] Therefore, the present inventors have studied the use of a magnetic field to control the orientation direction of the cylinder structure by overcoming the above technical problem. As a result, the magnetic field was applied to a sample having a thickness of 10 nm to 50 m. By applying a predetermined method, a block copolymer film having a cylindrical structure oriented in one predetermined direction and having streaky irregularities on the film surface is formed. Succeeded in getting.

[0014] An object of the present invention is to solve the disadvantages in the prior art and to provide a block copolymer film having a thin film thickness and having a cylinder structure oriented in a predetermined direction.

Means for solving the problem

[0015] The present invention is a block copolymer film having a cylinder structure oriented in a predetermined direction, having a thickness of 10ηπι to 50 / ζ πι, and having streaky surface irregularities The present invention relates to a copolymer film.

Further, in the present invention, the block structure is characterized in that the cylinder structure has an absolute value force of 0 ° or less of an orientation angle disturbance with respect to an orientation direction, which is defined by a small oblique incidence X-ray scattering measurement. The present invention relates to a polymer film.

Furthermore, the present invention relates to the block copolymer film having a cylinder structure oriented in one direction parallel to the film surface.

Furthermore, the present invention relates to a block copolymer comprising a transition to a predetermined unidirectionally oriented cylinder structure by applying a magnetic field to a disordered microphase-separated structure formed from a block copolymer. The present invention relates to a method for producing a combined membrane.

The invention's effect

[0016] According to the present invention, a block copolymer film having a thin film thickness and a cylinder structure oriented in a predetermined direction can be produced.

In addition, according to the present invention, in particular, the cylinder structure can be oriented in one direction parallel to the film surface with the force existing at least on the film surface in the thin film with the force that could not be realized so far. However, it is realizable by employ | adopting the method by a magnetic field application. As a result, it is possible to obtain a block copolymer film having specific fine streaky surface irregularities on the film surface.

Therefore, according to the present invention, it is possible to design highly functional materials in a wide range of fields. Examples of highly functional materials include nanowires. Further, the powerful high-functional material can be used for applications such as a high-functional optical material such as an optical retardation film.

Brief Description of Drawings FIG. 1 is a diagram showing an atomic force microscope observation image by a tapping mode method of a sample before applying a magnetic field (heat treated at 180 ° C. for 12 hours) in Example 1 in Example 1.

FIG. 2 is an atomic force microscope image of a sample obtained by applying a magnetic field of 30 Tesla at 180 ° C. for 3 hours in Example 1 using a tapping mode method.

[Fig. 3] Fig. 3 is an atomic force microscope image of the sample of Example 1 which was only heat-treated at 180 ° C for 3 hours without applying a magnetic field, by the tapping mode method.

[Fig. 4] Fig. 4 is a diagram showing the results of measurement of oblique angle of incidence and small angle X-ray scattering of a sample obtained by applying a magnetic field parallel to the surface of the thin film in Example 1.

[Figure 5] Figure 5 shows a two-dimensional scattered image (left) and the variation of the scattering intensity in the direction of the scattering vector shown in the figure, and the logarithm of the scattering intensity is plotted as a function of the scattering vector magnitude q. (Right)

[FIG. 6] FIG. 6 is a diagram in which the area of the primary peak shown in FIG. 5 is obtained and plotted with respect to the sample rotation angle Φ (azimuth angle) as Ι (φ).

BEST MODE FOR CARRYING OUT THE INVENTION

[0018] The block copolymer constituting the block copolymer film of the present invention is not limited as long as it does not depart from the object of the present invention, and any well-known block copolymer may be used. As block structures of the block copolymer, ΑΒ type, Α (ΒΑ) η type (where η represents a natural number, preferably η = 1 to 3), A (BAB) m, (m is A linear block copolymer represented by a natural number, preferably m = 1-2, or (AB) pX (where p represents a natural number, and preferably p = 3-5). X represents a polyfunctional functional group (atom group) that causes branching, and a star block copolymer having a B moiety as a bond center, represented by). Among these, in order to form a clear cylinder without branching or bending, AB type or ABA type block copolymers are preferred, and ABA type triblock copolymers are particularly preferred. Further, two or more of the above block copolymers may be blended and used.

[0019] Further, the block copolymer of the present invention is further blended with the above-mentioned one or more block copolymers with a homopolymer having a component (for example, A component and Z or B component) constituting each block. A membrane can also be constructed.

[0020] The block copolymer in the present invention comprises two or more, more preferably two types of repeating mono The block chain (polymer component) formed from at least one repeating monomer unit A is in a glassy state at 23 ° C, which corresponds to the normal casting temperature. Preferred because it is easy to freeze (immobilize). Further, in one embodiment of the present invention, it is preferred that the polymer component to be formed is a rubber state at 23 ° C. /.

The volume fraction of the polymer component (glass component) formed from the above repeating monomer unit A and the above repeating monomer unit B force formed polymer component (for example, rubber component) is either 0.1 to 0.4. Therefore, a component having a small volume fraction that is effective and preferable for forming a cylinder structure can form a cylinder structure, and a component having a large volume fraction can form a matrix phase. The volume fraction is preferably 0.11 to 0.35, more preferably 0.12 to 0.3 force, and particularly preferably 0.13 to 0.25. It is preferable to set the volume fraction of the polymer component (glass component) formed from repeating monomer units A to 0.1 to 0.4 because it is easy to form a cylinder structure. 11 to 0.35 is more preferable than force S, 0.12 to 0.3 force S is more preferable, 0.13 to 0.25 is particularly preferable, and 0.15 to 0.24 is most preferable. .

[0021] Repetitive monomer unit force Regarding the force with which the formed block chain (polymer component) is in a glass state or a rubber state, and the glass transition temperature of the polymer component, a general method for measuring the glass transition temperature, for example, It can be confirmed by differential scanning calorimetry (DSC) and dynamic viscoelasticity measurement.

[0022] The two or more kinds of repeating monomer units are preferably aromatic vinyl and a conjugation hydrogen partially or completely hydrogenated because it is easy to align in a magnetic field. Monomers that serve as the base for such aromatic bullets include styrene, α-methylstyrene, ρ-methylstyrene, vinyltoluene, t-butylstyrene, o-ethylstyrene, o-chlorostyrene, p-chlorostyrene, o, p-dichlorostyrene, p-bromostyrene, 2, 4, 5-tribromostyrene, and the like. Of these, styrene power is particularly preferred because it is available at the lowest cost.

In addition, the conjugate gen in the present invention originates from a monomer having a conjugated double bond in the same molecule, and the monomer serving as the base of the conjugate gen is not particularly limited. Conjugate Jen can be incorporated into the main chain of the polymer molecule (14 bonds) or into the side chain (1 to 2 bonds), but the ratio of both in the polymer molecule is There is no particular limitation. As the conjugated gen-based polymer, polybutadiene, polyisoprene, and styrene-butadiene random copolymer are suitable. In the present invention, a partially or completely hydrogenated conjugated diene as a repeating monomer unit is obtained by a conventional hydrogenation method of a conjugated gen-based polymer (for example, see JP-A-62-207303). It can be introduced into the block copolymer.

In the present invention, it is particularly preferred that the aromatic bul unit is a unit derived from styrene, and the partially or completely hydrogenated conjugation unit is a unit derived from butadiene.

[0023] The block copolymer of the present invention has a molecular weight that is at least equal to or higher than a molecular weight capable of microphase separation, and that can easily achieve a thermodynamic equilibrium or quasi-equilibrium state in a short time. It is important to have From such a viewpoint, the number average molecular weight is preferably in the range of 10,000 to 1,000,000. The number average molecular weight is more preferably 20,000 or more, more preferably 30,000 or more, and even more preferably 50,000 or more. Further, the number average molecular weight is more preferably 750,000 or less, more preferably 500,000 or less, still more preferably 200,000 or less.

[0024] The block copolymer film of the present invention has a cylinder structure oriented in a predetermined direction. That is, an important feature of the present invention includes that the block copolymer film has a cylinder structure and the cylinder structure is oriented in a predetermined direction. By imparting such characteristics to the block copolymer film, it becomes possible to design highly functional materials in a wide range of materials as described above.

Here, the predetermined one direction is an arbitrarily set direction, for example, one direction parallel to the film surface, a direction perpendicular to the film surface, and an arbitrary fixed angle (for example, 30 °). , 45 °, 60 °, etc.). In particular, in the case of having a cylinder structure oriented in a direction other than perpendicular, particularly in one direction parallel to the film surface, the production of a film having anisotropic nano-surface irregularities, and further, the obtained film is usually used. This method is particularly suitable for use in producing a substrate by decomposing and dissolving a polymer after performing metal vapor deposition by the method. [0025] Another important feature of the present invention is that the film thickness is in a specific range of 10 nm to 50 μm. By adopting the production method of the present invention described later, it becomes possible to produce a block copolymer film having a small film thickness that is suitable for each of the above-mentioned highly functional materials, which could not be obtained conventionally. It was. The film thickness is preferably 10 m or less, more preferably 5 / zm or less, still more preferably 1 μm or less, and particularly preferably lOOnm or less.

In the present invention, the film thickness can be measured by selecting an appropriate method according to the size range. For example, X-ray and neutron reflectivity measurement (about lOOnm or less), atomic force microscope (about 1 m or less), and ellipsometry (about 1 _μm or less).

[0027] According to the method of the present invention, the above-described cylinder structure oriented in one direction parallel to the film surface can be present at least on the film surface. By making the cylinder structure exist on the film surface, it is possible to obtain a block copolymer film having a liquid crystal alignment-inducing surface and a streaky surface unevenness difference of 2 to 20 nm. Here, the liquid crystal orientation inducing property means a property that liquid crystal molecules are spontaneously aligned in the axial direction and the parallel direction of the cylinder only by dropping a liquid crystal compound on the film. The presence of liquid crystal alignment-inducing properties can be confirmed by observing whether or not the dropped liquid crystal compound forms a monodomain aligned in one direction by using a polarizing microscope with an oblique incidence X-ray scattering (diffraction) method. it can. The height difference of the streaky surface irregularities is more preferably 2 to 15 nm, particularly preferably 2 to 10 nm. The height difference is preferably 15 to 40%, more preferably 15 to 30% with respect to the cylinder diameter.

The cylinder structure is preferably present at a depth of 5 to 50 nm, more preferably 5 to 25 nm from the film surface.

Whether or not the cylinder structure exists on the film surface, the depth of the film surface force, and the height difference of the surface irregularities can be determined by visual angle incidence small angle X-ray scattering and atomic force microscope observation or transmission electron microscope observation. Can be measured.

In the present invention, in the thin film, it is extremely important to orient the cylinder in a predetermined direction, particularly in one direction parallel to the film surface. That is, as a method for orienting the cylinder in a predetermined direction in the thin film, particularly in a direction parallel to the film surface, it is effective to adopt a method by applying a magnetic field as described later. Therefore, the book In a preferred block copolymer film of the invention, the orientation direction of the cylinder structure is defined by the direction of the applied magnetic field.

In general, when the film thickness is large, it is possible to orient the cylinder parallel to the film surface by applying a flow field, but for example, applying a flow field to a thin film with a film thickness of 10 m or less is not possible. It is extremely difficult. Even if it is possible to orient the cylinder structure perpendicular to the film surface in the thin film by applying an electric field, applying a temperature gradient, or zone heating, etc., it is possible to align it in a direction other than perpendicular, particularly parallel to the film surface. It is extremely difficult to apply these methods to thin films to orient the cylinder in one direction.

[0029] In the present invention, from the viewpoint of orienting the cylinder structure in a predetermined direction, for example, a direction other than vertical, in particular, one direction parallel to the film surface, and reducing the disturbance, The absolute value of the disorder of the orientation angle with respect to a given direction (specified by the oblique angle of incidence small-angle X-ray scattering measurement) is 40 ° or less.

The disorder of the orientation angle of a given unidirectional force on the film surface is a reaction caused by the regularity of the arrangement of the cylinder structure in the film surface, which is obtained when the oblique oblique incidence X-ray scattering measurement is performed. When plotting the spot intensity against the azimuth angle (azimuth angle deviation from one direction parallel to the film surface), the maximum reflected spot intensity force when the azimuth angle deviation is 0 ° is completely reduced. It is defined as the amount of change in the azimuth angle. Therefore, when the cylinder is oriented in a certain principal axis direction, a reflection spot appears that maximizes the azimuth angle position. Therefore, the azimuth angle that is completely reduced is regarded as a disorder of the orientation angle.

The absolute value of the disorder of the orientation angle is more preferably 20 ° or less, even more preferably 10 ° or less, and particularly preferably 5 ° or less. The lower limit of the absolute value of the disorder of the orientation angle is most preferably a force of 0 ° which can be about 0.5 °.

[0030] In addition, in the block copolymer film of the present invention, the cylinder structure is preferably arranged in a hexagonal lattice, and the viewpoint power of maximizing the number of filled cylinders is also preferred.

[0031] In the block copolymer film of the present invention, the cylinder structure is preferably a cylinder having a diameter of 3 to 50 nm from the viewpoint of forming streaky surface irregularities having a height difference of 2 to 20 nm. The diameter of the cylinder is more preferably 3 to 20 nm. Also such Syrin The cylinders are preferably arranged at a distance of 5 to 120 nm, more preferably 5 to 50 nm. Force From the viewpoint of maximizing the number of cylinders oriented parallel to a specific orientation. The cylinder diameter and the distance between the cylinders can be measured by transmission electron microscope observation, small-angle X-ray scattering method, and the like.

In the block copolymer film of the present invention, as described above, the component constituting the cylinder structure is a polymer component formed from repeated monomer units A, that is, a polymer component in a glassy state at 23 ° C. preferable.

Next, a preferable method for producing the block copolymer film of the present invention will be described in detail.

In a preferred embodiment of the present invention, a block copolymer sample (e.g., styrene ethylene butylene styrene triblock copolymer: SEBS) that can essentially form a cylindrical microphase separation structure is used. Precisely (preferably at a temperature above the glass transition temperature of the glass component (in this case, the polystyrene component) in the coalescence, preferably at least 80 ° C higher than the glass transition temperature of the polymer component constituting the cylinder. By performing heat treatment in a magnetic field so that the temperature of the heat-treated sample is uniform, the cylinder can be oriented parallel to the direction of the applied magnetic field.

[0033] In the production of the block copolymer film of the present invention, the relationship force between the cylinder orientation direction and the magnetic field application direction given to the block copolymer sample is particularly important. That is, it is important to apply a magnetic field in parallel to a predetermined direction in which the cylinder should be oriented.

[0034] The strength of the applied magnetic field is preferably 30 Tesla or lower, and a superconducting electromagnet more preferably 10 Tesla or lower is not required in order to apply a magnetic field at a low cost, which is preferably 2 Tesla or lower. Is particularly preferred. In order to generate a sufficient magnetic torque for orienting the cylinder, the strength of the applied magnetic field is preferably 0.1 Tesla or more.

[0035] In the above method, it is also possible to form a cylinder by utilizing the structural transition due to the self-organization ability of the block copolymer during application of a magnetic field. Therefore, the present invention also includes a transition to a cylinder structure oriented in a predetermined direction by applying a magnetic field to a disordered microphase-separated structure formed from a block copolymer. The present invention also relates to a method for producing a copolymer film. Here, the structure of the block copolymer before application of a magnetic field is preferably a disordered microphase separation structure from the viewpoint of easy transition to a cylinder and easy orientation. Further, the structure of the block copolymer before application of the magnetic field is preferably in a completely compatible state after microphase separation, and the point force for reducing the disorder of the orientation angle is particularly preferable.

[0037] In the production of the block copolymer film of the present invention, it is important to perform the heat treatment under precise temperature control. For example, at a temperature not lower than the glass transition temperature of polystyrene (for example, 150 ° C), preferably at least 80 ° C higher than the glass transition temperature of the polymer component constituting the cylinder, more preferably higher than 90 ° C. More preferably, the temperature is 100 ° C or higher, particularly preferably 110 ° C or higher, and precisely (preferably ± 1 ° C, more preferably 0.5 ° C). ), Heat treatment is performed so as to achieve a uniform temperature distribution as much as possible so that temperature unevenness and temperature gradient do not occur for a predetermined time (for example, 3 hours). As a result, a cylinder structure oriented in a predetermined direction, which is defined by the direction of the applied magnetic field, and preferably parallel to the direction of the applied magnetic field, is formed.

[0038] Furthermore, in the case of preparing a thin film with a polymer solution strength, it is preferable to use a spin casting method. That is, a thin film is prepared by dropping 0.1 to 1 ml of a polymer solution (concentration 0.1 to 1% by weight) onto a silicon wafer placed on a stage rotating at a speed of 1000 rpm or more. The thickness of the thin film can be adjusted in the range of 10 nm to 100 nm depending on the rotational speed, the concentration of the polymer solution, and the amount of the dropped solution.

[0039] According to the present invention, as described above, it is possible to design highly functional materials in a wide range of fields. Examples of the high-functional material include nanowires. Further, such a high-functional material can be used for applications such as a high-functional optical material such as an optical retardation film. In the present invention, the optical material includes a polarizing plate protective film used for a display such as a liquid crystal display, a plasma display, an organic EL display, a field emission display, and a rear projection television, and a phase such as a 1Z4 wavelength plate and a 1Z2 wavelength plate. Examples include a liquid crystal optical compensation film such as a difference plate, a viewing angle control film, a display front plate, a display substrate, a lens, and a transparent substrate used for solar cells. The block copolymer film of the present invention can be particularly suitably used for these optical materials.

[0040] The matrix phase on the surface of the block copolymer film of the present invention is subjected to the same method as described above. The nanocylinder alignment film can be obtained by removing by decomposition or dissolution. Here, it is important that the orientation and alignment of the outermost nanocylinder structure are not disturbed. Therefore, the depth of the surface to be removed is preferably 2 nm or more, more preferably 5 nm or more, and 25 nm or less, more preferably 15 nm or less.

Such a nanocylinder alignment film preferably has a liquid crystal alignment-inducing surface. Here, the liquid crystal alignment inducing property means a property that liquid crystal molecules are spontaneously aligned in a direction parallel to the axial direction of the cylinder only by dropping a liquid crystal compound onto the film. The existence of liquid crystal orientation-inducing properties is observed by observing whether the dropped liquid crystal compound forms a monodomain oriented in one direction by using a polarizing microscope with an oblique incidence X-ray scattering (diffraction) method. Can be confirmed.

[0041] Also, a block copolymer sample is spin-cast on the surface of the above-mentioned nanocylinder alignment film, and this is further heat-treated, whereby a laminate including at least the nanocylinder alignment film and the block copolymer film of the present invention. A nanocylinder-oriented retardation film having a structure can be obtained. Such a nanocylinder-oriented retardation film is a laminated film having a uniform cylinder orientation direction. Here, it is preferable to use a selective solvent that does not dissolve the components forming the matrix phase when performing spin casting. Further, by repeating this lamination, a laminated film having a thickness of preferably 100 to 200 nm is obtained, which is particularly useful as a nanocylinder-oriented retardation film for optical materials.

Here, the selective solvent refers to a solvent that corresponds to a selective good solvent for a certain type of polymer component, and that corresponds to a selective poor solvent for another type of polymer component. In the case of removing the selective solvent from the polymer solution, it is preferable that the polymer solution is concentrated to completely evaporate the selective solvent to form an absolutely dry cast film.

[0043] When the matrix phase is removed from the block copolymer film of the present invention by decomposition or dissolution, nanowires can be obtained. The decomposition method is not particularly limited, and a force that can employ a conventionally known method, for example, a method such as ozonolysis or ion beam etching is recommended. Also, the dissolution method is not particularly limited, and a conventionally known method can be adopted.For example, a solvent capable of dissolving only one of the polymers forming the cylinder or the matrix (for example, the glass component dissolves but the rubber component Do not dissolve the solvent, A method using a solvent that dissolves the rubber component but not the glass component, or a method using an acid or alkali is recommended. The nanowire obtained in this manner is preferably an elongated wire-like material having a diameter of about 1 to 100 nm, and has a length of 10 to LOOO times the diameter. Nanowires imparted with conductivity by using a conductive polymer as the block copolymer in the present invention are extremely useful. Example

[0044] Hereinafter, the effectiveness of the present invention will be described with reference to examples. The present invention is not limited to these examples. The methods for evaluating physical properties in the following examples are as follows.

[0045] 1. Disturbance of orientation angle

The disorder of the orientation angle of the specific azimuth force of the cylinder structure on the film surface was determined according to the following method.

Disturbance of the orientation angle with a specific azimuth force on the film surface indicates the reflection spot intensity resulting from the regularity of the arrangement of the cylinder structure, which is obtained when X-ray scattering measurement is performed at a small oblique angle of incidence. When plotted against azimuth angle deviation from azimuth), it is defined as the amount of change in azimuth angle when the maximum reflection spot intensity is completely reduced when the azimuth angle deviation is 0 °. Therefore, when the cylinder is oriented in a certain principal axis direction, the reflection spot intensity appears so that the position of the azimuth angle becomes the maximum value, so that the orientation angle is disordered with the azimuth angle completely reduced. And

For measurement, the irradiation X-ray beam size at the sample position is 1. Omm in the horizontal direction, 0.7 mm in the vertical direction (rectangular beam cross section), the wavelength is 0.1499 nm, and the incident angle of X-rays to the sample surface is 0.15. ° Using the imaging plate (Fuji film) at the beam line BL40B2 of the Research Center for High-Intensity Optical Science (SPring-8). Fuji BAS2000 was used for reading. The resolution (size) of one pixel was 100 m × 100 m.

The disorder of the orientation angle was determined as follows. That is, the reflection spot intensity is plotted against the azimuth as shown in Fig. 6, and the following formula:

ΐ () = ΑΐΒη! ι [Γ (-Δ) + 1] + Β

[Where φ is the azimuth angle, I (φ) is the reflection spot intensity, Α, Β and Γ are fittings It is a parameter. ]

Determined by parameter fitting using the hyperbolic tangent function shown in

Δφ is the disorder of the orientation angle.

Whether the cylinder structure is oriented in one predetermined direction was confirmed as follows. That is, it was confirmed that the reflection spot intensity obtained when X-rays were incident at an oblique angle from the direction parallel to the magnetic field application direction was the strongest. That is, as shown in FIG. 6, the case where the azimuth angle is zero degrees corresponds to that.

[0046] 2. Distance between cylinders

The distance between the cylinders was measured according to the following method.

Small angle X-ray scattering measurement was performed, the scattering angle dependence of the scattering intensity was plotted, and the scattering angle Θ was determined from the position of the first peak of the lattice scattering factor that appeared (the peak that appeared at the position where the scattering angle was the smallest). . This is Bragg's reflection condition formula:

2d sin (Θ / 2) = η λ

(In the formula, d is the distance between the reflecting surfaces, Θ is the scattering angle, n is a natural number (here, especially for the first-order peak, n = 1), and λ represents the X-ray wavelength)

By substituting into, the distance d between the reflecting surfaces was obtained. Relationship between d and distance between cylinders L:

L = (2/3 ^{0 5} ) X d

Was used to determine the distance between the cylinders.

[0047] 3. Cylinder diameter

The cylinder diameter was measured according to the following method.

The scattering angle dependence of the scattering intensity was plotted, and the scattering angle 0 was obtained from the position of the primary peak of the particle scattering factor that appeared. This is the formula:

P

(4 π / λ) 5ίη (Θ / 2) = 4. 98 / R

Ρ

Substituting into, the cylinder radius R was calculated to determine the cylinder diameter.

[0048] [Example 1]

As the block copolymer, styrene-ethylenebutylene-styrene triblock copolymer (SEBS) (Tuftec (registered trademark) H1062 manufactured by Asahi Kasei Chemicals Corporation) was used. Sample is , Volume fraction 10.16 polystyrene (PS), the number-average molecular weight (M) is 6. 6 X 10 ^4, polydispersity index of the molecular weight distribution (M / M) is 1.03, polyethylene butylene (PEB) Chain Inside

w n

The mole fraction of chain was 0.41.

The sample was dissolved in toluene so that the polymer concentration was 1% by weight, and a thin film having a thickness of 20 nm was prepared on a silicon wafer by spin casting at room temperature (23 ° C). That is, 0.1 ml of the polymer solution was dropped on a silicon wafer placed on a stage rotating at a speed of 3000 revolutions per minute, and the rotation was continued for 60 seconds to completely evaporate the solvent and prepare a thin film. The silicon wafer was manufactured by Laco and was cut out into a 6 mm X 8 mm rectangle without any surface treatment as it was purchased.

[0049] The thickness of the thin film was measured by an atomic force microscope observation by a tapping mode method.

That is, the depth of the damaged groove was analyzed by damaging the thin film attached on the silicon wafer with an injection needle and observing the portion with an atomic force microscope (uneven image). The depth of the groove thus obtained corresponds to the thickness of the thin film.

[0050] Nanoscope Ilia manufactured by Digital Instruments was used for atomic force microscope observation by the tapping mode method. The surface of a thin film sample on a silicon wafer was observed at room temperature while vibrating a probe with a length of 124 m and a panel constant of 66 NZm ^{2 at} a resonance frequency of 3 95 kHz. Image) and images corresponding to the softness (phase image) were obtained.

The obtained spin cast sample was heat-treated in an oven under reduced pressure for 12 hours at 180 ° C. Using this sample, a magnetic field of 30 Tesla was applied while heat-treating at 180 ° C for 3 hours. The equipment used was a hybrid magnet installed at the Strong Magnetic Field Research Center of the National Institute for Materials Science. This hybrid magnet has a bore with a diameter of 52 mm, and the sample holder is heated by a heater embedded in the inner wall of the bore. The temperature of the sample was measured with a resistance temperature detector. A thin film sample obtained by spin casting was inserted into the sample holder together with the silicon wafer, and a magnetic field application heat treatment was performed. The spin-cast silicon wafer with a thin film sample was inserted vertically into the sample holder. Since the direction of the magnetic field is vertical, the magnetic field is applied in one direction parallel to the sample surface. These specimens were observed by atomic force microscopy using the tapping mode method and small angle X-ray scattering measurement of oblique oblique incidence at the beam line BL40B2 of the High Brightness Optical Science Research Center (SPring-8).

[0051] [Sample before magnetic field application]

Figure 1 shows an atomic force microscope image of the sample before magnetic field application (heat treated at 180 ° C for 12 hours) by the tapping mode method. Observation was performed at room temperature (23 ° C). It should be noted that the thickness of the thin film is 20 nm, which is slightly larger than the cylinder diameter of 13 nm, but that the conditions are such that multiple cylinders do not stack in the thickness direction of the film. The stripe pattern observed in Fig. 1 indicates that the cylinders are arranged parallel to the silicon wafer surface, that is, the surface of the thin film. Locally, the cylinders are arranged at regular intervals, but the orientation direction is not limited to one direction. Here, since the concavo-convex image and the phase image correspond to each other, it can be seen that a single cylinder structure formed of a hard and polystyrene component protrudes slightly on the surface.

[Sample after magnetic field application]

On the other hand, as shown in Fig. 2, in the case of applying a magnetic field of 30 Tesla for 3 hours at 180 ° C, the cylinder is oriented along the direction of the applied magnetic field.

[0053] [Small angle X-ray scattering measurement of oblique viewing angle]

In order to clarify whether the cylinder is actually oriented parallel to the direction of the applied magnetic field, small-angle X-ray scattering measurements were performed. The purpose of this measurement is to evaluate the disturbance by quantitatively determining the orientation angle with respect to the applied magnetic field direction.

Figure 4 shows the results of small-angle X-ray scattering measurement of the sample with a magnetic field applied parallel to the surface of the thin film. The measurement was performed at room temperature (23 ° C). In order to clarify the relationship between the direction of the applied magnetic field and the orientation direction of the cylinder, the sample was rotated with the normal direction of the sample surface as the rotation axis. By this operation, the measurement result was obtained every 10 ° from parallel (rotation angle 0 °) to vertical (rotation angle 90 °). Fig. 4 shows excerpts of rotation angles of 0 °, 50 ° and 90 °. In either result, a pair of strong reflection spots can be confirmed in the horizontal direction. This indicates that cylinders parallel to the surface of the thin film sample and parallel to the incident X-ray direction are regularly arranged at regular intervals. Rotation angle is 0 It can also be seen that the reflection spot intensity decreases when the force is increased to 90 °. In order to quantitatively evaluate this tendency, the change in the scattering intensity in the direction of the scattering vector shown in the two-dimensional scattering image in Fig. 5 was examined.

[0054] The logarithm of the scattering intensity was plotted in FIG. 5 as a function of the scattering vector magnitude q. The upper force is also the result obtained for each of the rotational angle forces of 0 °, 10 °, 20 °, 30 °, 40 °, 50 °, 60 °, 70 °, 80 °, and 90 °. The size of the scattering vector q is given by the equation: q = (4 w Z sin (0 Z2)

[Where λ is the X-ray wavelength and Θ is the scattering angle. ]

Defined by When the rotation angle is 0 °, secondary reflection can be confirmed, indicating that the regularity of the cylinder arrangement is high. In order to remove background intensity from the primary peak, peak separation was performed to obtain the peak area.

When the peak area was plotted against the rotation angle (that is, the angle between the X-ray incident direction and the magnetic field application direction), the dependence shown in Fig. 6 was shown. That is, the intensity of the primary reflection spot is the maximum at a rotation angle of 0 ° (when the X-ray incident direction is parallel to the magnetic field application direction), which is defined by the direction of the applied magnetic field in the cylinder structure. This indicates that the film is oriented in one direction. In addition, it reached an almost constant value at a rotation angle of 34 °.

Therefore, from this result, it was determined that the disorder of the orientation angle of the cylinder was 34 °.

[0055] The film thickness of the block copolymer film (magnetic field applied sample) obtained in Example 1 was 20 nm, the disorder of the orientation angle was 34 °, the cylinder diameter was 13.2 nm, and the distance between the cylinders was 30.2 nm. In particular, a film material useful as a liquid crystal alignment-inducing film having surface irregularities of several nanometers was obtained. When the surface was observed with an atomic force microscope, the surface irregularities were streaks, and the difference in height was 2.0 to 2.2 nm.

[0056] [Comparative Example 1]

Silicon wafers with thin film samples are placed vertically in a magnetic field, so there is concern about the effects of gravity. Therefore, the other conditions were exactly the same, and a sample was prepared that was only heat-treated without applying a magnetic field. The results are shown in Fig. 3.

Fig. 3 is clearly different from Fig. 2, and it was found that the orientation direction of the cylinder is not defined in one direction. Therefore, the results in Figure 2 are pure and not influenced by gravity. In other words, it is the effect of applying a magnetic field.

The main aspects and preferred aspects of the present invention are listed below.

[1] A block copolymer film having a cylinder structure oriented in a predetermined direction, and ΙΟηπ! A block copolymer film having a film thickness of ~ and having streaky surface irregularities. [2] The cylinder structure according to [1], wherein the absolute value force of the disorder of the orientation angle with respect to the orientation direction is 0 ° or less as defined by the oblique incidence small-angle X-ray scattering measurement. Block copolymer film.

[3] The block copolymer film according to the above [1] or [2], which has a cylinder structure oriented in one direction parallel to the film surface.

[4] The block copolymer film according to [3], wherein the cylinder structure oriented in one direction parallel to the film surface exists at least on the film surface.

[5] The block copolymer film according to any one of the above [1] to [4], which has a liquid crystal alignment-inducing surface and the height difference between the streaky surface irregularities is 2 to 20 nm.

[6] The block copolymer film according to any one of [1] to [5], wherein the orientation direction of the cylinder structure is defined by the direction of the applied magnetic field.

[7] The block copolymer film according to any one of [1] to [6], wherein the cylinder structure is arranged on a hexagonal lattice.

[8] The block copolymer comprises at least two types of repeating monomer unit forces, and the polymer component formed from at least one type of repeating monomer unit A is in a glassy state at 23 ° C. 7]. The block copolymer film according to any one of the above.

[9] The block copolymer film according to the above [8], wherein the volume fraction of the polymer component formed with respect to the block copolymer of the repeating monomer unit A force is 0.1 to 0.4.

[10] The block copolymer film according to the above [9], wherein the component constituting the cylinder structure is a polymer component formed repeatedly from monomer unit A.

[11] The block copolymer film according to any one of [1] to [10], wherein the cylinder structure has a cylinder force with a diameter of 3 to 50 nm.

[12] The block copolymer film according to [11], wherein the cylinders are arranged at intervals of 5 to 120 nm. [13] The block copolymer according to any one of [8] to [12], wherein the at least two types of repeating monomer units are an aromatic bul unit and a partially or completely hydrogenated conjugation unit. Polymer film.

[14] The block co-polymer according to [13], wherein the aromatic bul unit is a unit derived from styrene, and the partially or completely hydrogenated conjugation unit is a unit derived from butadiene. Combined membrane.

[15] The block copolymer film according to any one of [1] to [14] above, wherein the number average molecular weight of the block copolymer is 10,000 to 1,000,000.

[16] The block copolymer film according to any one of [2] to [15], wherein the absolute value of the disorder of the orientation angle with respect to the orientation direction is 10 ° or less.

[17] A nano-cylinder alignment film that is removed by matrix force decomposition or dissolution on the surface of the block copolymer film according to any one of [1] to [16].

[18] The nanocylinder alignment film according to [17], which has a liquid crystal alignment-inducing surface. [19] A nanocylinder having a laminated structure including at least the nanocylinder alignment film according to [17] or [18] and the block copolymer film according to any one of [1] to [15] Oriented retardation film.

[20] A nanowire obtained by removing the matrix phase from the block copolymer film according to any one of [1] to [16] by decomposition or dissolution.

[21] The above-mentioned [1] to [15], comprising applying a magnetic field to a disordered microphase-separated structure formed from a block copolymer, thereby causing a transition to a cylinder structure oriented in a predetermined direction. ] The manufacturing method of the block copolymer film | membrane in any one of.

[22] Disordered microphase separation structural force The method for producing a block copolymer film as described in [21] above, wherein the transition to the cylinder structure is caused by the self-organization ability of the block copolymer.

[23] The method for producing a block copolymer film according to any one of the above [21] to [22], which comprises orienting the cylinder structure in a direction in which a magnetic field is applied.

[24] The method according to any one of [21] to [23], wherein the magnetic field is applied at a temperature not lower than the glass transition temperature of the polymer component constituting the cylinder. [25] The method described in [24] above, wherein the magnetic field is applied with a temperature accuracy of ± 1 ° C that is 80 ° C or higher than the glass transition temperature of the polymer component constituting the cylinder. Industrial applicability

According to the present invention, it is oriented in a predetermined direction, preferably in one direction parallel to the surface of the thin film, preferably has a cylinder structure with a small disorder of the orientation angle, and has streaky surface irregularities. It is possible to produce a block copolymer film having

According to the present invention, high-performance materials can be designed in a wide range of fields. Examples of highly functional materials include nanowires. Moreover, the highly functional material that can be used can be used for applications such as a highly functional optical material.

Claims

The scope of the claims

[I] A block copolymer film having a cylinder structure oriented in a predetermined direction, 10 ηπ! A block copolymer film having a film thickness of ˜50 m and having streaky surface irregularities.

[2] The block according to claim 1, wherein the cylinder structure has an absolute value force of 0 ° or less of disorder of the orientation angle with respect to the orientation direction, which is defined by a small angle of incidence X-ray scattering measurement. Copolymer film.

[3] The block copolymer film according to [1] or [2] having a cylinder structure oriented in one direction parallel to the film surface.

4. The block copolymer film according to claim 3, wherein the cylinder structure oriented in one direction parallel to the film surface exists at least on the film surface.

[5] The block copolymer film according to any one of [1] to [4], wherein the block copolymer film has a liquid crystal alignment-inducing surface, and the height difference between the streaky surface irregularities is 2 to 20 nm.

[6] The orientation direction of the cylinder structure is defined by the direction of the applied magnetic field.

V, block copolymer film according to any of the above.

[7] The block copolymer film according to any one of [1] to [6], wherein the cylinder structures are arranged on a hexagonal lattice.

[8] The block copolymer comprises at least two types of repeating monomer unit forces,

The block copolymer film according to any one of claims 1 to 7, wherein the polymer component in which one kind of repeating monomer unit A force is formed is in a glass state at 23 ° C.

[9] The block copolymer film according to [8], wherein the volume fraction of the repeating monomer unit A force formed with respect to the block copolymer of the polymer component is 0.1 to 0.4.

10. The block copolymer film according to claim 9, wherein the component constituting the cylinder structure is a polymer component formed repeatedly from monomer unit A.

[II] The block copolymer film according to any one of claims 1 to 10, wherein the cylinder structure has a cylinder force with a diameter of 3 to 50 nm.

12. The block copolymer film according to claim 11, wherein the cylinders are arranged at intervals of 5 to 120 nm.

[13] The at least two types of repeating monomer units may be aromatic bull units and partially or The block copolymer film according to any one of claims 8 to 12, which is a unit of conjugation hydrogen completely hydrogenated.

14. The block copolymer film according to claim 13, wherein the aromatic bul unit is a unit derived from styrene, and the partially or completely hydrogenated conjugation unit is a unit derived from butadiene.

[15] The block copolymer film according to any one of [1] to [14], wherein the block copolymer has a number average molecular weight of 10,000 to 1,000,000.

[16] The block copolymer film according to any one of [2] to [15], wherein the absolute value of the disorder of the orientation angle relative to the orientation direction is 10 ° or less.

[17] A nanocylinder alignment film obtained by removing the matrix phase on the surface of the block copolymer film according to any one of claims 1 to 16 by decomposition or dissolution.

18. The nanocylinder alignment film according to claim 17, which has a liquid crystal alignment inducing surface.

[19] A nanocylinder alignment retardation film having a laminated structure including at least the nanocylinder alignment film according to claim 17 or 18 and the block copolymer film according to any one of claims 1 to 15.

[20] A nanowire obtained by removing the matrix phase from the block copolymer film according to any one of claims 1 to 16 by decomposition or dissolution.

[21] According to any one of claims 1 to 15, comprising applying a magnetic field to a disordered microphase-separated structure formed from a block copolymer to transfer to a predetermined unidirectionally oriented cylinder structure. The manufacturing method of the block copolymer film | membrane in any one.

[22] The method for producing a block copolymer film according to claim 21, wherein the disordered microphase separation structural force is caused by the self-assembly ability of the block copolymer.

[23] The method according to claim 21, comprising orienting the cylinder structure in a direction in which a magnetic field is applied.

3. The method for producing a block copolymer film according to any one of 2 above.

24. The method according to any one of claims 21 to 23, wherein the magnetic field is applied at a temperature not lower than the glass transition temperature of the polymer component constituting the cylinder.

[25] Apply a magnetic field of 80 ° C or more from the glass transition temperature of the polymer components that make up the cylinder. 25. The method of claim 24, wherein the method is performed at a high temperature and with a temperature accuracy of ± 1 ° C.