JP7210372B2 - METHOD FOR MANUFACTURING SHEET CONTAINING PATTERN STRUCTURE - Google Patents

Description

The present invention relates to a method for manufacturing a pattern structure containing sheet. Specifically, the present invention relates to a method for producing a pattern structure-containing sheet, which includes the step of forming a pattern on a pattern-forming substrate containing fine fibrous cellulose.

BACKGROUND ART In recent years, attention has been paid to materials using reproducible natural fibers due to the replacement of petroleum resources and the growing awareness of the environment. Among natural fibers, fibrous cellulose having a fiber diameter of 10 μm or more and 50 μm or less, particularly wood-derived fibrous cellulose (pulp) has been widely used mainly as paper products.

As fibrous cellulose, fine fibrous cellulose having a fiber diameter of 1 μm or less is also known. Also, a sheet composed of such fine fibrous cellulose and a composite comprising a sheet containing fine fibrous cellulose and a resin layer have been developed. The use of such sheets and composites as optical members has also been investigated.

For example, Patent Documents 1 to 4 disclose that a composite sheet is formed by impregnating a sheet containing fine fibrous cellulose with a resin component, and the composite sheet is used as a wiring board or a circuit board. . Further, Patent Document 5 discloses a cellulose fiber composite film containing cellulose fibers and a low-molecular-weight lubricant, and the use of such a composite film for a wiring board is being studied.

By the way, when forming a wiring board or a circuit board, a patterning process may be performed using an exposure apparatus. In recent years, miniaturization and high integration of wiring boards and circuit boards have been studied, and along with this, shortening of the wavelength of the light source for exposure may be required. For example, Patent Literature 6 discloses a vacuum ultraviolet light irradiation device including a lamp housing that emits light including vacuum ultraviolet light and other predetermined structures.

JP-A-2005-060680 JP 2016-089022 A JP 2018-132655 A JP 2018-170518 A JP 2017-078151 A JP 2015-126044 A

When a composite sheet containing fine fibrous cellulose as described above is used as a substrate for pattern formation, the substrate is required to enable highly accurate pattern formation. However, in the prior art, sufficient studies have not been made on techniques for forming a highly accurate pattern on a pattern-forming base material containing fine fibrous cellulose.

Therefore, in order to solve such problems of the prior art, the present inventors have developed a method for producing a pattern structure-containing sheet capable of forming a highly accurate pattern on a pattern-forming base material containing fine fibrous cellulose. We proceeded with the study with the aim of providing

As a result of intensive studies to solve the above problems, the present inventors have found that a base layer containing fibrous cellulose having a fiber width of 1000 nm or less and a resin layer are formed on the pattern forming base material. It was found that a highly accurate pattern can be formed by irradiating a vacuum ultraviolet ray after placing a photomask for formation and further applying a conductive material to the vacuum ultraviolet ray irradiated portion.
Specifically, the present invention has the following configurations.

[1] A step of placing a pattern forming photomask on a pattern forming base material having a base layer containing fibrous cellulose with a fiber width of 1000 nm or less and a resin layer, and irradiating vacuum ultraviolet rays;
A method for producing a pattern structure-containing sheet, comprising a step of applying a conductive material to the vacuum ultraviolet ray irradiated portion on the pattern forming substrate to form a pattern.
[2] The method for producing a pattern structure-containing sheet according to [1], wherein, in the step of forming a pattern, a pattern having a thinnest line of 1 μm or more and 1 mm or less is formed.
[3] The method for producing a pattern structure containing sheet according to [1] or [2], wherein the step of irradiating vacuum ultraviolet rays is a step of irradiating vacuum ultraviolet rays as parallel light.
[4] The method for producing a pattern structure-containing sheet according to any one of [1] to [3], wherein oxygen exists between the photomask and the pattern forming substrate in the step of irradiating with vacuum ultraviolet rays.
[5] The method for producing a pattern structure-containing sheet according to any one of [1] to [4], wherein the base layer containing fibrous cellulose further contains a hydrophilic polymer.
[6] The method for producing a pattern structure-containing sheet according to any one of [1] to [5], wherein the fibrous cellulose contains a phosphorous acid group or a substituent derived from a phosphorous acid group.
[7] The method for producing a pattern structure-containing sheet according to any one of [1] to [6], wherein the pattern forming substrate has a haze of 10% or less.

According to the production method of the present invention, it is possible to obtain a pattern structure-containing sheet on which a highly accurate pattern is formed.

FIG. 1 is a cross-sectional view illustrating the structure of a pattern forming substrate. FIG. 2 is a schematic diagram illustrating the configuration of a vacuum ultraviolet light irradiation treatment apparatus used in the method for producing a patterned structure-containing sheet of the present invention. FIG. 3 is a cross-sectional view illustrating the configuration of the pattern structure-containing sheet obtained by the pattern structure-containing sheet manufacturing method of the present invention. FIG. 4 is a graph showing the relationship between the amount of dropped NaOH and the pH for a fibrous cellulose-containing slurry having a phosphorous acid group. FIG. 5 is a graph showing the relationship between the dropping amount of NaOH and the pH for a fibrous cellulose-containing slurry having carboxyl groups.

The present invention will be described in detail below. Although the constituent elements described below may be described based on representative embodiments and specific examples, the present invention is not limited to such embodiments.

(Manufacturing method of pattern structure-containing sheet)
The present invention relates to a method for manufacturing a pattern structure containing sheet. In the method for producing a pattern structure-containing sheet of the present invention, a photomask for pattern formation is placed on top of a pattern formation base material having a base layer containing fibrous cellulose with a fiber width of 1000 nm or less and a resin layer, The method includes a step of irradiating vacuum ultraviolet rays, and a step of applying a conductivity-developing material to the vacuum ultraviolet-ray-irradiated portions on the pattern-forming substrate to form a pattern. In the present invention, a highly accurate pattern is formed on the pattern structure-containing sheet obtained through such manufacturing steps.

In the method for producing a pattern structure-containing sheet of the present invention, a photomask for pattern formation is placed on top of a pattern formation base material having a base layer containing fibrous cellulose with a fiber width of 1000 nm or less and a resin layer, A step of irradiating vacuum ultraviolet rays is included. In this step, a pattern-forming substrate is placed at a predetermined position in a vacuum ultraviolet light irradiation treatment apparatus, and vacuum ultraviolet rays are irradiated from above a photomask placed above the pattern-forming substrate. In this specification, vacuum ultraviolet rays are ultraviolet rays with a wavelength of 200 nm or less, and may also be referred to as VUV. Note that the wavelength of the vacuum ultraviolet rays may be 160 nm or longer.

FIG. 1 is a cross-sectional view illustrating the structure of a pattern-forming substrate used in the method for producing a pattern structure-containing sheet of the present invention. As shown in FIG. 1, the pattern forming substrate 20 has a base layer 22 comprising microfibrous cellulose and a resin layer 24 . The base layer 22 and the resin layer 24 are laminated so as to be in contact with each other on one side. The pattern forming base material may have at least one base layer 22 and at least one resin layer 24, but may have two or more base layers 22 and two or more resin layers 24. may be For example, a structure having resin layers 24 on both sides of the base layer 22 may be used.
In this specification, fibrous cellulose having a fiber width of 1000 nm or less is sometimes referred to as fine fibrous cellulose or CNF.

FIG. 2 is a schematic diagram illustrating the configuration of a vacuum ultraviolet light irradiation treatment apparatus used in the method for producing a patterned structure-containing sheet of the present invention. As shown in FIG. 2, the vacuum ultraviolet light irradiation processing apparatus 100 includes a processing chamber 5 in which a lamp housing 3, a transparent window portion 4, and a work stage 7 on which a pattern forming substrate 20 is installed are arranged. and The lamp housing 3 and the processing chamber 5 are hermetically connected via a transparent window 4 . It is preferable that the lamp housing 3 is provided above the processing chamber 5 as long as the vacuum ultraviolet rays are irradiated from the lamp housing 3 to the processing chamber 5 .

Inside the lamp housing 3, a VUV short arc flash lamp 1 (VUV-SFL) that emits vacuum ultraviolet light and a parabolic mirror 2 are provided. and power supply means 11 for supplying electric power are connected. The power feeding means 11 includes a power supply section 13 including a capacitor to be charged with energy and a step-up transformer, a trigger circuit section 12 for generating a trigger pulse for starting, and a charger 14 for charging the capacitor of the power supply section 13, and is a compact power supply. The portion 13 and the trigger circuit portion 12 may be installed inside the lamp housing 3 .

The light emitted from the flash lamp 1 is collimated by the parabolic mirror 2 and then transmitted through the transmissive window 4 to irradiate the pattern forming substrate 20 placed in the processing chamber 5 . That is, the step of irradiating the vacuum ultraviolet rays is preferably a step of irradiating the pattern forming substrate 20 with the vacuum ultraviolet rays as parallel light. In this specification, parallel light refers to light emitted parallel to the optical axis of the reflector. is emitted. Then, the emitted parallel light is irradiated at the same angle onto the surface of the pattern forming substrate 20 placed in the processing chamber 5 . In the present embodiment, parallel light is light that is applied perpendicularly to the surface of the pattern forming substrate 20 . Here, in this specification, parallel light includes substantially parallel light.

The transmissive window part 4 has a high transmittance with respect to vacuum ultraviolet rays (VUV). In addition, the transparent window 4 is assembled so that the lamp housing 3 and the processing chamber 5 are each kept airtight. No gas permeation. The interior of the lamp housing 3 is purged by introducing an inert gas such as N.sub.2 gas from a _first gas introduction port 3a provided in the lamp housing 3. As shown in FIG. The inert gas such as N ₂ gas introduced into the lamp housing 3 passes through the power supply unit 13 of the power supply unit 11, the trigger circuit unit 12, the parabolic mirror 2, the through hole at the top of the parabolic mirror 2, and the flash lamp. 1 reaches the flash lamp 1 through the gap between the outer surface of the lamp 1 and after cooling them, is exhausted from the first exhaust port 3 b provided in the lamp housing 3 .

At least one or more passage holes 3 c may be provided around the transmissive window 4 of the lamp housing 3 to spatially connect the inner space of the lamp housing 3 and the inside of the processing stage 5 . Inside the processing chamber 5, a mask upper space A, which is a space between the transparent window portion 4 and the photomask 6, and a pattern forming substrate 20 on the lower surface of the photomask 6 are provided by the photomask 6. It is divided into a work processing space B and a work processing space B. Therefore, the passage hole 3c spatially connects the inside of the lamp housing 3 and the mask upper space A, but the mask upper space A and the work processing space B are not communicated with each other. The space A above the mask is provided with a second exhaust port 5a.

A work stage 7 on which a pattern forming substrate 20 is placed is provided in the processing chamber 5 . On the work stage 7, the resin layer 24 of the pattern forming substrate 20 is placed on the upper surface (exposed surface). When patterning the pattern forming substrate 20, a photomask 6 having a transfer pattern (light transmissive intermittent portions) is provided between the pattern forming substrate 20 and the transmissive window portion 4. . The photomask 6 is, for example, provided with a metal thin film or the like as a member made of a material that does not transmit vacuum ultraviolet rays (VUV) on one surface of a material that transmits vacuum ultraviolet rays (VUV). An intermittent portion that transmits vacuum ultraviolet rays (VUV) is provided in the portion. Alternatively, the photomask 6 may be a metal mask in which intermittent portions are formed by processing such as etching in a metal material. As a result, part of the parallel light emitted from the lamp housing 3 passes through the intermittent portions of the photomask 6 and reaches the pattern forming substrate 20 .

Here, since the work processing space B of the processing chamber 5 is under atmospheric conditions, oxygen is present in the work processing space B. As shown in FIG. That is, oxygen exists between the photomask 6 and the pattern forming substrate 20 described above. A gas containing oxygen may be introduced into the work processing space B from the second gas inlet 5b, the work processing space B may be purged with the gas, and then exhausted from the third gas exhaust port 5c. . Under such conditions, when the resin layer 24 of the pattern forming substrate 20 is irradiated with vacuum ultraviolet rays (VUV), only the portions of the resin layer 24 irradiated with the vacuum ultraviolet rays (VUV) become lyophilic. That is, the VUV-irradiated portions of the resin layer 24 are formed according to the pattern shape of the intermittent portions of the photomask 6, and the VUV-irradiated portions become lyophilic by the irradiation of the VUV.

The lyophilicity of the resin layer 24 in the pattern forming substrate 20 can be determined by measuring the solution contact angle of the exposed portion of the surface of the pattern forming substrate 20 irradiated with vacuum ultraviolet rays (VUV). For example, when the resin layer 24 on the pattern forming base material 20 is made hydrophilic by irradiation with vacuum ultraviolet rays (VUV), hydrophilization (lyophilicity) can be confirmed by measuring water contact on the surface of the pattern forming base material 20 . can determine what has been done. In this case, if the water contact angle of the surface of the pattern forming substrate 20 irradiated with vacuum ultraviolet rays (VUV) is 50° or less, the resin layer 24 on the pattern forming substrate 20 becomes hydrophilic (lyophilic). can be determined. The water contact angle of the surface of the pattern forming substrate 20 is preferably 40° or less, more preferably 30° or less. Here, the water contact angle of the surface of the pattern-forming substrate is the water contact angle of the exposed portion of the surface of the resin layer of the pattern-forming substrate. The water contact angle on the surface of the pattern forming substrate is the water contact angle 5 seconds after dropping 1 μL of distilled water on the surface of the pattern forming substrate. A dynamic water contact angle tester is used for the measurement. As a dynamic water contact angle tester, for example, 1100DAT manufactured by Fibro can be used.

As shown in FIG. 2, there is a gap between the photomask 6 and the pattern forming substrate 20, and oxygen is present in the gap. In order to provide such a gap, the gap may be formed by inserting a tape-shaped gap forming member between both ends of the photomask 6 and the pattern forming substrate 20 .

As the vacuum ultraviolet light irradiation processing apparatus 100 described above, for example, a VUV patterning experimental machine SUS740 manufactured by Ushio Inc. can be used.

In the method for producing a pattern structure-containing sheet of the present invention, following the step of irradiating the pattern forming substrate 20 with the vacuum ultraviolet rays as described above, a conductive material is applied to the vacuum ultraviolet ray irradiated portion of the pattern forming substrate. The step of applying to form a pattern is included. In the step of forming a pattern, a conductive material is applied onto the exposed pattern forming substrate 20 . It is preferable that the material for exhibiting conductivity is applied after the pattern forming substrate 20 is removed from the exposure device.

Various methods such as coating, spraying, and impregnation can be employed as the method of applying the conductive material. Among them, it is preferable to apply the conductive material by a coating method. In this case, for example, a blade coater, an air knife coater, a roll coater, a bar coater, a gravure coater, a micro gravure coater, a rod blade coater, or the like can be used as the coating device.

Examples of electroconductivity-developing materials include metal-containing compositions and conductive polymer-containing compositions. The conductive material may be a material having conductivity or a material capable of acquiring conductivity in the process of forming the pattern structure. When a metal-containing composition is used as the conductive material, examples of metals contained in the metal-containing composition include Ag, Au, Cu, Al, Fe, Zn, Ni, Cr, and Mo. Also, the metal-containing composition may be a composition containing oxides of the metals described above. The metal-containing composition may contain additives such as solvents and dispersants. Examples of metal-containing compositions that can be used include metal inks and metal pastes, and metal nanoparticle inks. etc. can also be used.

When a conductive polymer-containing composition is used as a conductive material, examples of the conductive polymer contained in the conductive polymer-containing composition include polythiophene-based conductive polymer, polypyrrole-based conductive polymer, and polyaniline. conductive polymers, poly(p-phenylenevinylene)-based conductive polymers, polyquinoxaline-based conductive polymers, and the like. A polythiophene-based conductive polymer is preferable from the viewpoint of a good balance among optical properties, appearance, antistatic properties, coatability, stability, and the like. Examples of polythiophene-based conductive polymers include polyethylenedioxythiophene and polythiophene. These conductive polymers may be used singly or in combination of two or more.

In the step of applying the conductivity-developing material to the vacuum ultraviolet irradiation portion on the pattern-forming base material 20 , after applying the conductivity-developing material to the entire surface of the pattern-forming base material 20 , the vacuum on the pattern-forming base material 20 is applied. It is preferable to include a step of removing the conductive material from the area other than the ultraviolet irradiation area. As a result, the conductivity-developing material is applied only to the VUV-irradiated portion of the pattern-forming substrate 20 . The coating thickness of the conductive material is preferably 0.1 μm or more, more preferably 1 μm or more, and even more preferably 2 μm or more. Further, the coating thickness of the electroconductive material is preferably 50 μm or less, more preferably 30 μm or less.

A drying process may be provided after applying the electroconductivity-developing material. The drying temperature at this time is preferably 50° C. or higher, more preferably 60° C. or higher, and even more preferably 70° C. or higher. The drying temperature is preferably 200° C. or lower, more preferably 180° C. or lower, and even more preferably 160° C. or lower. The drying time in the drying step is preferably 1 minute or longer, more preferably 2 minutes or longer. The drying time is preferably 60 minutes or less, more preferably 40 minutes or less.

A pattern structure containing sheet in which a pattern structure is formed on the pattern forming substrate 20 is obtained through the steps described above. FIG. 3 is a cross-sectional view illustrating the configuration of a pattern structure-containing sheet 50 obtained by the pattern structure-containing sheet manufacturing method of the present invention. As shown in FIG. 3 , in the pattern structure-containing sheet 50 , a vacuum ultraviolet irradiation portion 52 (lyophilic portion) is formed on the resin layer 24 of the pattern forming substrate 20 . A conductive portion 54 made of a conductive material is laminated thereon. In FIG. 3, since the layer structure of the vacuum ultraviolet irradiation part 52 and the conductive part 54 is drawn for easy understanding, the thickness of each layer and the thickness ratio are not necessarily the same as the actual structure of the pattern structure containing sheet. Absent.

In the present invention, by using the pattern-forming substrate 20 and the above-described vacuum ultraviolet light irradiation treatment apparatus, a pattern having the finest line of 1 μm or more and 1 mm or less can be formed. Here, the thinnest line is the width of the thinnest line among the pattern structures formed on the pattern forming substrate 20 . The width of the thinnest line is the width indicated as L in FIG. The width of the space in the pattern is shown as S in FIG. Among the pattern structures formed on the pattern forming substrate 20, the width of the thinnest line can be appropriately adjusted depending on the application. is also possible. Also, the width of the narrowest space can be appropriately adjusted depending on the application, and it is possible to form a fine space structure of 50 μm or less, 40 μm or less, or 30 μm or less. The width of the thinnest line and the width of the thinnest space are preferably 1 μm or more. The width of the thinnest line on the pattern forming substrate 20 can be measured by observing with an optical microscope.

(Pattern forming substrate)
The pattern-forming substrate used in the method for producing a pattern structure-containing sheet of the present invention includes a base layer containing fibrous cellulose with a fiber width of 1000 nm or less, and a resin layer. FIG. 1 is a cross-sectional view illustrating the configuration of a pattern forming base material 20 used in the method for producing a pattern structure containing sheet of the present invention. As shown in FIG. 1, the pattern forming substrate 20 has a base layer 22 comprising microfibrous cellulose and a resin layer 24 . In the present invention, by using the pattern forming substrate 20 including the base layer 22 containing fibrous cellulose with a fiber width of 1000 nm or less, the dimensional stability of the pattern forming substrate 20 can be improved, and as a result, high A precise pattern structure can be formed.

The overall thickness of the pattern forming substrate is not particularly limited, but is preferably 10 μm or more, more preferably 20 μm or more, and even more preferably 30 μm or more. In addition, the total thickness of the pattern forming substrate is preferably 1000 mm or less, more preferably 700 μm or less, and even more preferably 500 μm or less. It is preferable that the thickness of the pattern forming base material is appropriately adjusted according to the shape of the pattern to be formed and its application.

The thickness of the base layer of the pattern forming substrate is preferably 5 μm or more, more preferably 10 μm or more, and even more preferably 15 μm or more. Also, the thickness of the base layer is preferably 995 μm or less, more preferably 695 μm or less, and even more preferably 495 μm or less. Here, the thickness of the base layer constituting the pattern-forming substrate is determined by cutting out a cross-section of the pattern-forming substrate with an ultramicrotome UC-7 (manufactured by JEOL) and observing the cross-section with an electron microscope, a magnifying glass, or visually. is the measured value. When the substrate for pattern formation includes a plurality of base layers, the total thickness of the base layers is preferably within the above range.

The thickness of the resin layer of the pattern forming substrate is preferably 0.1 μm or more, more preferably 1 μm or more. Also, the thickness of the resin layer is preferably 20 μm or less, more preferably 15 μm or less, and even more preferably 10 μm or less. Here, the thickness of the resin layer constituting the pattern-forming substrate is determined by cutting out a cross-section of the pattern-forming substrate with an ultramicrotome UC-7 (manufactured by JEOL) and observing the cross-section with an electron microscope, a magnifying glass, or visually. It is a value that is observed and measured. When a plurality of resin layers are included in the pattern forming substrate, the total thickness of the resin layers is preferably within the above range.

The density of the pattern forming substrate is preferably 1.00 g/cm ³ or more, more preferably 1.10 g/cm ³ or more, and even more preferably 1.20 g/cm ³ or more. The density of the substrate for pattern formation was calculated by dividing the basis weight of the substrate for pattern formation by the thickness. The thickness of the pattern forming substrate can be measured with a stylus thickness gauge (Millitron 1202D, manufactured by Marl Co.).

The total light transmittance of the pattern forming substrate is preferably 60% or higher, more preferably 70% or higher, even more preferably 80% or higher, and particularly preferably 90% or higher. By setting the total light transmittance of the pattern-forming substrate within the above range, the suitability of the pattern-forming substrate is enhanced in cases such as optical positioning in the patterning process. Here, the total light transmittance is a value measured according to JIS K 7361 using a haze meter (HM-150, manufactured by Murakami Color Research Laboratory).

The haze of the substrate for pattern formation is preferably 10.0% or less, more preferably 5.0% or less, even more preferably 2.5% or less, even more preferably 2.0% or less, and 1.5% or less. More preferably, 1.0% or less is particularly preferable. By setting the haze of the pattern-forming substrate within the above range, the suitability of the pattern-forming substrate is enhanced in the case of performing optical positioning in the patterning process. Here, the haze is a value measured using a haze meter (HM-150, manufactured by Murakami Color Research Laboratory Co., Ltd.) in accordance with JIS K 7136.

The tensile modulus of the pattern forming substrate at 23° C. and 50% relative humidity is preferably 2.5 GPa or more, more preferably 3.0 GPa or more, and even more preferably 5.0 GPa or more. , more preferably 7.0 GPa or more, even more preferably 8.0 GPa or more, and particularly preferably 9.0 GPa or more. Further, the tensile modulus of the pattern forming substrate at 23° C. and 50% relative humidity is preferably 30 GPa or less. The tensile modulus of the pattern forming substrate is a value measured in accordance with JIS P 8113, and the tensile modulus is a value calculated from the maximum positive slope value of the SS curve (stress-strain curve). is.

After holding the pattern forming substrate at a temperature of 110° C. in a nitrogen atmosphere for 1 hour, the shrinkage rate is preferably less than 1.5%, more preferably 1.2% or less. It is more preferably 0% or less, even more preferably 0.8% or less, and particularly preferably 0.7% or less. By setting the shrinkage rate of the pattern forming substrate within the above range, the patterning properties can be further enhanced. Here, the shrinkage rate of the pattern-forming base material was determined by setting the pattern-forming base material having a width of 3 mm and a length of 30 mm in a thermomechanical analyzer, and then setting the tension mode to a chuck distance of 20 mm, a load of 10 g, and a nitrogen atmosphere. , is the dimensional change rate after heating from room temperature to 110° C. at a rate of 5° C./min and then holding for 1 hour. Specifically, it is a value calculated by the following formula.
Shrinkage rate (%) = |BA|/A x 100
A is the chuck-to-chuck distance (mm) in the initial state (room temperature) set in the analyzer, and B is the chuck-to-chuck distance (mm) after the temperature is raised to 110° C. and held for 1 hour.

The coefficient of linear thermal expansion of the substrate for pattern formation is preferably 50 ppm/K or less,
It is more preferably 40 ppm/K or less, and even more preferably 30 ppm/K or less. The coefficient of linear thermal expansion of the substrate for pattern formation was determined by setting the substrate for pattern formation with a width of 4 mm and a length of 30 mm in a thermomechanical analyzer (manufactured by Hitachi High-Tech Corporation, TMA7100). , is a value calculated from measured values from 100°C to 150°C when the temperature is raised from room temperature to 180°C at a rate of 5°C/min in a nitrogen atmosphere and the temperature is lowered from 180°C to 25°C at a rate of 5°C/min.

The surface roughness (arithmetic average) of the pattern forming substrate is preferably 10 nm or less, more preferably 8 nm or less, even more preferably 6 nm or less, and particularly preferably 4 nm or less. Here, the surface roughness (arithmetic mean) of the pattern forming substrate is the arithmetic mean roughness of the surface of the resin layer of the pattern forming substrate. The surface roughness (arithmetic average) is a value obtained by measuring the arithmetic average roughness of 10 μm square using an atomic force microscope (NanoScope IIIa manufactured by Veeco).

The water contact angle of the surface of the pattern forming substrate is preferably 60° or more, more preferably 65° or more, and even more preferably 70° or more. Here, the water contact angle on the surface of the pattern forming substrate is the water contact angle on the surface of the resin layer of the pattern forming substrate. The water contact angle on the surface of the pattern forming substrate is the water contact angle 30 seconds after dropping 4 μL of distilled water onto the surface of the pattern forming substrate. A dynamic water contact angle tester is used for the measurement. As a dynamic water contact angle tester, for example, 1100DAT manufactured by Fibro can be used.

The water contact angle on the surface of the pattern-forming substrate after the pattern-forming substrate is irradiated with vacuum ultraviolet rays (VUV) for 5 minutes is preferably 50° or less, more preferably 40° or less. , 30° or less. By setting the water contact angle of the surface of the pattern forming substrate after 5 minutes of vacuum ultraviolet (VUV) irradiation within the above range, pattern formation with higher precision becomes possible. The water contact angle is a value in a vacuum ultraviolet (VUV) irradiated portion of the surface of the pattern forming base material.

(resin layer)
The resin layer is a layer containing natural resin or synthetic resin as a main component. Here, the main component refers to a component that is contained in an amount of 50% by mass or more with respect to the total mass of the resin layer. The content of the resin is preferably 60% by mass or more, more preferably 70% by mass or more, further preferably 80% by mass or more, and 90% by mass with respect to the total mass of the resin layer. It is particularly preferable that it is above. In addition, the content of the resin may be 100% by mass, or may be 95% by mass or less.

Examples of natural resins include rosin-based resins such as rosin, rosin esters, and hydrogenated rosin esters.

The synthetic resin is preferably at least one selected from, for example, polycarbonate resin, polyethylene terephthalate resin, polyethylene naphthalate resin, polyethylene resin, polypropylene resin, polyimide resin, polystyrene resin, urethane resin and acrylic resin. Among them, the synthetic resin is preferably at least one selected from polycarbonate resins, urethane resins and acrylic resins, more preferably at least one selected from urethane resins and acrylic resins. The acrylic resin is preferably at least one selected from polyacrylonitrile, poly(meth)acrylate and urethane acrylate.

Examples of the polycarbonate resin constituting the resin layer include aromatic polycarbonate resins and aliphatic polycarbonate resins. Specific polycarbonate-based resins for these are known, and include, for example, the polycarbonate-based resins described in JP-A-2010-023275.

The resin layer preferably contains a hydrophobic resin. In this specification, a hydrophobic resin is defined as a resin having a contact angle with water of 60 degrees or more in a dry state. Here, "in a dry state" means excluding a state in which the hydrophobic resin has an affinity for water, such as when the hydrophobic resin is in an emulsion state.

In the pattern forming substrate, the resin layer may contain an adhesion aid. Examples of adhesion promoters include compounds containing at least one selected from isocyanate groups, carbodiimide groups, epoxy groups, oxazoline groups, amino groups and silanol groups, and organosilicon compounds. Among them, the adhesion aid is preferably at least one selected from compounds containing an isocyanate group (isocyanate compounds) and organosilicon compounds. Examples of organic silicon compounds include condensates of silane coupling agents and silane coupling agents.

The isocyanate compound is a polyisocyanate compound or includes a higher polyfunctional isocyanate. Specific examples of polyisocyanate compounds include aromatic polyisocyanates having 6 to 20 carbon atoms excluding carbon atoms in the NCO group, aliphatic polyisocyanates having 2 to 18 carbon atoms, and 6 to 15 carbon atoms. Alicyclic polyisocyanates, aralkyl polyisocyanates having 8 to 15 carbon atoms, modified products of these polyisocyanates, and mixtures of two or more thereof can be mentioned. Among them, alicyclic polyisocyanates having 6 to 15 carbon atoms, that is, isocyanurates, are preferably used.

Specific examples of alicyclic polyisocyanates include isophorone diisocyanate (IPDI), dicyclohexylmethane-4,4'-diisocyanate (hydrogenated MDI), cyclohexylene diisocyanate, methylcyclohexylene diisocyanate, bis(2-isocyanatoethyl). -4-cyclohexene-1,2-dicarboxylate, 2,5-norbornane diisocyanate, 2,6-norbornane diisocyanate and the like.

Examples of the organic silicon compound include compounds having a siloxane structure and compounds forming a siloxane structure by condensation. Examples include silane coupling agents and condensates of silane coupling agents. The silane coupling agent may have a functional group other than an alkoxysilyl group, or may have no other functional group. Functional groups other than alkoxysilyl groups include vinyl groups, epoxy groups, styryl groups, methacryloxy groups, acryloxy groups, amino groups, ureido groups, mercapto groups, sulfide groups, and isocyanate groups. The silane coupling agent used in the present invention is preferably a silane coupling agent containing a methacryloxy group.

Specific examples of silane coupling agents having a methacryloxy group in the molecule include methacryloxypropylmethyldimethoxysilane, methacryloxypropyltrimethoxysilane, methacryloxypropylmethyldiethoxysilane, methacryloxypropyltriethoxysilane, 1,3-bis(3-methacryloxypropyl)tetramethyldisiloxane and the like. Among them, at least one selected from methacryloxypropyltrimethoxysilane, methacryloxypropyltriethoxysilane and 1,3-bis(3-methacryloxypropyl)tetramethyldisiloxane is preferably used. The silane coupling agent preferably contains 3 or more alkoxysilyl groups.

In the silane coupling agent, it is preferable that silanol groups are formed after hydrolysis, and that at least part of the silanol groups remain even after lamination of the base layer. Since the silanol group is a hydrophilic group, it is possible to increase the adhesion between the resin layer and the base layer by increasing the hydrophilicity of the base layer side surface of the resin layer.

The adhesion aid may be contained in a uniformly dispersed state in the resin layer. Here, the state in which the adhesion aid is uniformly dispersed in the resin layer means that the concentrations of the following three regions ((a) to (c)) are measured and the concentrations of any two regions are compared. It refers to the state in which there is no difference of 2 times or more.
(a) A region extending from the base layer side surface of the resin layer to 10% of the total thickness of the resin layer (b) From the surface opposite to the base layer side surface of the resin layer to 10% of the total thickness of the resin layer Area (c) Area of ± 5% of the total thickness from the center plane in the thickness direction of the resin layer (total 10%)

Further, the adhesion aid may be unevenly distributed in the region of the resin layer on the base layer side. For example, when an organosilicon compound is used as the adhesion aid, the organosilicon compound may be unevenly distributed in the region of the resin layer on the base layer side.
Here, the state in which the resin layer is unevenly distributed in the region on the base layer side means that the two densities of the following regions ((d) and (e)) are measured, and the difference in these densities is more than twice. It means the state of coming out.
(d) A region from the base layer side surface of the resin layer to 10% of the total thickness of the resin layer (e) A region of ±5% of the total thickness (total 10%) from the center plane in the thickness direction of the resin layer Here , the concentration of the adhesion aid is a numerical value measured by an X-ray electron spectrometer or an infrared spectrophotometer, and a cross section of a predetermined region of the pattern forming substrate with an ultramicrotome UC-7 (manufactured by JEOL) is cut out and the cross section is measured by the device.

An organic silicon compound-containing layer may be provided on the base layer side surface of the resin layer, and such a state is also included in the state in which the organic silicon compound is unevenly distributed in the base layer side region of the resin layer. The organic silicon compound-containing layer may be a coating layer formed by applying an organic silicon compound-containing coating liquid.
When an organosilicon compound-containing layer is provided on the surface of the resin layer on the base layer side, in the above region (d), "the surface of the resin layer on the base layer side" means "the exposure of the organosilicon compound-containing layer. surface", and "thickness of the entire resin layer" shall be read as "total thickness of the resin layer and the organosilicon compound-containing layer".

The content of the adhesion aid is preferably 0.1 parts by mass or more, more preferably 0.5 parts by mass or more with respect to 100 parts by mass of the resin contained in the resin layer. Also, the content of the adhesion aid is preferably 40 parts by mass or less, more preferably 35 parts by mass or less with respect to 100 parts by mass of the resin contained in the resin layer.
When the adhesion aid is an isocyanate compound, the content of the isocyanate compound is preferably 10 parts by mass or more, more preferably 15 parts by mass or more, relative to 100 parts by mass of the resin contained in the resin layer. It is more preferably 18 parts by mass or more. In addition, the content of the isocyanate compound is preferably 40 parts by mass or less, more preferably 35 parts by mass or less, and 30 parts by mass or less with respect to 100 parts by mass of the resin contained in the resin layer. More preferred.
When the adhesion aid is an organosilicon compound, the content of the organosilicon compound is preferably 0.1 parts by mass or more, and is preferably 0.5 parts by mass or more with respect to 100 parts by mass of the resin contained in the resin layer. It is more preferable to have The content of the organosilicon compound is preferably 10 parts by mass or less, more preferably 5 parts by mass or less with respect to 100 parts by mass of the resin contained in the resin layer.
By setting the content of the adhesion aid within the above range, the adhesion between the base layer and the resin layer can be more effectively enhanced.

When the adhesion aid is an isocyanate compound, the content of isocyanate groups contained in the resin layer is preferably 0.5 mmol/g or more, more preferably 0.6 mmol/g or more, and more preferably 0.8 mmol/g. /g or more, and particularly preferably 0.9 mmol/g or more. In addition, the content of isocyanate groups contained in the resin layer is preferably 3.0 mmol/g or less, more preferably 2.5 mmol/g or less, and further preferably 2.0 mmol/g or less. It is preferably 1.5 mmol/g or less, and particularly preferably 1.5 mmol/g or less.

A surface treatment may be applied to the surface of the resin layer on the base layer side. Examples of surface treatment methods include corona treatment, plasma discharge treatment, UV irradiation treatment, electron beam irradiation treatment, and flame treatment. Among them, the surface treatment is preferably at least one selected from corona treatment and plasma discharge treatment. The plasma discharge treatment is preferably vacuum plasma discharge treatment.

The surface of the resin layer on the base layer side may form a fine uneven structure. When the surface of the resin layer on the base layer side has a fine uneven structure, the adhesion between the base layer and the resin layer can be more effectively enhanced. When the base layer side surface of the resin layer has a fine uneven structure, such a structure may be formed by a treatment process such as blasting, embossing, etching, corona treatment, plasma discharge treatment, or the like. preferable. In this specification, the term “fine uneven structure” refers to a structure in which 10 or more recesses are present on a single straight line with a length of 1 mm drawn at an arbitrary location. When measuring the number of concave portions, the substrate for pattern formation is immersed in ion-exchanged water for 24 hours, and then the base layer is peeled off from the resin layer. Thereafter, measurement can be performed by scanning the base layer side surface of the resin layer with a stylus type surface roughness meter (Surfcorder series manufactured by Kosaka Laboratory Co., Ltd.). When the pitch of the unevenness is extremely small on the order of submicrons or nano-orders, the number of unevenness can be measured from an observation image of a scanning probe microscope (AFM5000II and AFM5100N, manufactured by Hitachi High-Tech Science).

The resin layer may contain optional components other than the synthetic resin. Examples of optional components include known components used in the field of resin films, such as fillers, pigments, dyes, and ultraviolet absorbers.

(base layer)
The base layer contains fibrous cellulose (fine fibrous cellulose) with a fiber width of 1000 nm or less. The content of fine fibrous cellulose is preferably 50% by mass or more, more preferably 60% by mass or more, still more preferably 70% by mass or more, and 80% by mass of the total mass of the base layer. % or more is particularly preferable.

The density of the base layer is preferably 1.0 g/cm ³ or higher, more preferably 1.1 g/cm ³ or higher, and even more preferably 1.2 g/cm ³ or higher. Also, the density of the base layer is preferably 1.8 g/cm ³ or less, more preferably 1.6 g/cm ³ or less. When the pattern forming base material includes two or more base layers, the density of each base layer is preferably within the above range.

The density of the base layer is calculated according to JIS P 8118 from the basis weight and thickness of the base layer. The basis weight of the base layer can be calculated according to JIS P 8124 by cutting the pattern forming base material with an ultramicrotome UC-7 (manufactured by JEOL) so that only the base layer remains. When the base layer contains optional components other than the fine fibrous cellulose, the density of the base layer is the density containing the optional components other than the fine fibrous cellulose.

The present invention is also characterized in that the base layer is a non-porous layer. Here, that the base layer is non-porous means that the density of the whole base layer is 1.0 g/cm ³ or more. If the density of the entire base layer is 1.0 g/cm ³ or more, it means that the porosity contained in the base layer is suppressed to a predetermined value or less, and is distinguished from porous sheets and layers.
The non-porous base layer is also characterized by a porosity of 15% by volume or less. The porosity of the base layer referred to here is simply obtained by the following formula (a).
Formula (a): Porosity (% by volume) = [1-B / (M × A × t)] × 100
Here, A is the area of the base layer (cm ² ), t is the thickness of the base layer (cm), B is the mass of the base layer (g), and M is the density of solids constituting the base layer.

<Fine fibrous cellulose>
The base layer contains fibrous cellulose with a fiber width of 1000 nm or less. The fiber width of fibrous cellulose is preferably 100 nm or less, more preferably 8 nm or less. As a result, the dispersibility in the solvent can be more effectively enhanced, making it easier to obtain a high-strength and highly transparent base layer.

The fiber width of fibrous cellulose can be measured, for example, by electron microscopic observation. The average fiber width of fibrous cellulose is, for example, 1000 nm or less. The average fiber width of the fibrous cellulose is, for example, preferably 2 nm or more and 1000 nm or less, more preferably 2 nm or more and 100 nm or less, even more preferably 2 nm or more and 50 nm or less, and 2 nm or more and 10 nm or less. Especially preferred. By setting the average fiber width of fibrous cellulose to 2 nm or more, it becomes easier to suppress dissolution in water as cellulose molecules. The fibrous cellulose is, for example, single fibrous cellulose.

The average fiber width of fibrous cellulose is measured, for example, using an electron microscope as follows. First, an aqueous suspension of fibrous cellulose with a concentration of 0.05% by mass or more and 0.1% by mass or less is prepared, and this suspension is cast on a hydrophilized carbon film-coated grid to form a sample for TEM observation. and SEM images of surfaces cast on glass may be observed if they contain wide fibers. Then, an electron microscope image is observed at a magnification of 1,000, 5,000, 10,000, or 50,000 times depending on the width of the fiber to be observed. However, the sample, observation conditions and magnification are adjusted so as to satisfy the following conditions.
(1) A single straight line X is drawn at an arbitrary point in the observed image, and 20 or more fibers intersect the straight line X.
(2) Draw a straight line Y that intersects the straight line perpendicularly in the same image, and 20 or more fibers intersect the straight line Y.
Widths of fibers intersecting the straight lines X and Y are visually read from the observation image satisfying the above conditions. In this way, at least three sets of observed images of surface portions that do not overlap each other are obtained. Then, for each image, the width of the fiber that crosses straight line X and straight line Y is read. This gives at least 20 x 2 x 3 = 120 fiber width readings. Then, the average value of the read fiber widths is taken as the average fiber width of the fibrous cellulose.

Although the fiber length of the fibrous cellulose is not particularly limited, it is preferably 0.1 μm or more and 1000 μm or less, more preferably 0.1 μm or more and 800 μm or less, and further preferably 0.1 μm or more and 600 μm or less. preferable. By setting the fiber length within the above range, destruction of the crystalline regions of the fibrous cellulose can be suppressed. Moreover, it becomes possible to make the slurry viscosity of fibrous cellulose into an appropriate range. The fiber length of fibrous cellulose can be determined by image analysis using, for example, TEM, SEM, and AFM.

Preferably, the fibrous cellulose has a Type I crystal structure. Here, the fact that the fibrous cellulose has a type I crystal structure can be identified in a diffraction profile obtained from a wide-angle X-ray diffraction photograph using CuKα (λ=1.5418 Å) monochromated with graphite. Specifically, it can be identified by having typical peaks at two positions near 2θ=14° or more and 17° or less and 2θ=22° or more and 23° or less. The proportion of the I-type crystal structure in the fine fibrous cellulose is, for example, preferably 30% or more, more preferably 40% or more, even more preferably 50% or more. As a result, even better performance can be expected in terms of heat resistance and low coefficient of linear thermal expansion. The degree of crystallinity is determined by a conventional method from the pattern of X-ray diffraction profiles (Seagal et al., Textile Research Journal, vol. 29, p. 786, 1959).

Although the axial ratio (fiber length/fiber width) of fibrous cellulose is not particularly limited, it is preferably 20 or more and 10,000 or less, and more preferably 50 or more and 1,000 or less. A sheet containing fine fibrous cellulose can be easily formed by making the axial ratio equal to or higher than the above lower limit. By setting the axial ratio to the above upper limit or less, handling such as dilution becomes easier, for example, when fibrous cellulose is treated as a dispersion liquid, which is preferable.

The fibrous cellulose in this embodiment has, for example, both a crystalline region and an amorphous region. In particular, fine fibrous cellulose having both a crystalline region and an amorphous region and having a high axial ratio is realized by a method for producing fine fibrous cellulose, which will be described later.

The fibrous cellulose preferably has an ionic substituent. When the fibrous cellulose has an ionic substituent, the dispersibility of the fibrous cellulose in the dispersion medium can be improved, and the defibration efficiency in the fibrillation treatment can be increased. The ionic substituents can include, for example, either one or both of an anionic group and a cationic group. In this embodiment, it is particularly preferable to have an anionic group as an ionic substituent.

Examples of the anionic group as the ionic substituent include, for example, a phosphorous acid group or a substituent derived from a phosphoroxoacid group (sometimes simply referred to as a phosphorous acid group), a carboxy group or a substituent derived from a carboxyl group (simply called a carboxyl group ), a carboxymethyl group, and a sulfone group or a substituent derived from a sulfone group (sometimes simply referred to as a sulfone group). Among them, the anionic group is more preferably at least one selected from a phosphate group and a carboxy group, and particularly preferably a phosphate group. By introducing a phosphorus oxoacid group as an anionic group, the dispersibility of fibrous cellulose can be further improved, for example, even under alkaline or acidic conditions, and as a result, a high-strength and highly transparent base layer can be obtained. easier.

A phosphorous acid group or a substituent derived from a phosphorous acid group is, for example, a substituent represented by the following formula (1). Phosphorus oxoacid group is a divalent functional group corresponding to, for example, phosphoric acid from which a hydroxy group has been removed. Specifically, it is a group represented by —PO ₃ H ₂ . Substituents derived from a phosphorous acid group include substituents such as a salt of a phosphorous acid group and a phosphorous acid ester group. The substituent derived from the phosphorous oxoacid group may be contained in the fibrous cellulose as a condensed group of a phosphoric acid group (for example, a pyrophosphate group). Further, the phosphorous acid group may be, for example, a phosphorous acid group (phosphonic acid group), and the substituent derived from the phosphorous acid group may be a salt of a phosphorous acid group, a phosphite ester group, or the like. good too.

In formula (1), a, b and n are natural numbers (where a=b×m). a of α ^{1 , α 2} , . Note that all of α ⁿ and α′ may be O ⁻ . Each R is a hydrogen atom, a saturated-linear hydrocarbon group, a saturated-branched hydrocarbon group, a saturated-cyclic hydrocarbon group, an unsaturated linear hydrocarbon group, an unsaturated-branched hydrocarbon group A hydrogen group, an unsaturated-cyclic hydrocarbon group, an aromatic group, or a derivative group thereof. Moreover, it is preferable that n is 1.

Examples of the saturated straight-chain hydrocarbon group include, but are not limited to, methyl group, ethyl group, n-propyl group, n-butyl group, and the like. The saturated-branched hydrocarbon group includes i-propyl group, t-butyl group and the like, but is not particularly limited. The saturated cyclic hydrocarbon group includes, but is not particularly limited to, a cyclopentyl group, a cyclohexyl group, and the like. The unsaturated straight-chain hydrocarbon group includes, but is not particularly limited to, a vinyl group, an allyl group, and the like. The unsaturated-branched hydrocarbon group includes i-propenyl group, 3-butenyl group and the like, but is not particularly limited. The unsaturated-cyclic hydrocarbon group includes, but is not limited to, a cyclopentenyl group, a cyclohexenyl group, and the like. The aromatic group includes, but is not particularly limited to, a phenyl group, a naphthyl group, or the like.

In addition, as the derivative group in R, at least one functional group such as a carboxy group, a hydroxy group, or an amino group is added or substituted with respect to the main chain or side chain of the above various hydrocarbon groups. Examples include, but are not limited to, groups. Although the number of carbon atoms constituting the main chain of R is not particularly limited, it is preferably 20 or less, more preferably 10 or less. By setting the number of carbon atoms constituting the main chain of R within the above range, the molecular weight of the phosphorous acid group can be set within an appropriate range, facilitating penetration into the fiber raw material and increasing the yield of fine cellulose fibers. can also

β ^b+ is a monovalent or higher cation composed of an organic substance or an inorganic substance. Examples of monovalent or higher-valent cations composed of organic substances include aliphatic ammonium and aromatic ammonium. Examples include cations of divalent metals such as calcium and magnesium, hydrogen ions, and the like, but are not particularly limited. These may be applied singly or in combination of two or more. As the cation having a valence of 1 or more composed of an organic substance or an inorganic substance, sodium or potassium ions are preferable, but not particularly limited, because they are less likely to turn yellow when fiber raw materials containing β are heated and are easily industrially available. Note that β ^b+ may be an organic onium ion, and in this case, an organic ammonium ion is particularly preferred.

The amount of the ionic substituent introduced into the fibrous cellulose is, for example, preferably 0.10 mmol/g or more, more preferably 0.20 mmol/g or more, more preferably 0.50 mmol per 1 g (mass) of fibrous cellulose. /g or more, and particularly preferably 1.00 mmol/g or more. In addition, the amount of the ionic substituent introduced into fibrous cellulose is, for example, preferably 5.20 mmol/g or less, more preferably 3.65 mmol/g or less per 1 g (mass) of fibrous cellulose. It is more preferably 0.50 mmol/g or less, and even more preferably 3.00 mmol/g or less. By setting the amount of the ionic substituent to be introduced within the above range, the fiber raw material can be easily made finer, and the stability of the fibrous cellulose can be enhanced. Here, the denominator in units of mmol/g indicates the mass of fibrous cellulose when the counter ion of the ionic substituent is hydrogen ion (H ⁺ ).

The amount of ionic substituents introduced into fibrous cellulose can be measured, for example, by a neutralization titration method. In the measurement by the neutralization titration method, the introduced amount is measured by determining the pH change while adding an alkali such as an aqueous sodium hydroxide solution to the obtained slurry containing the fibrous cellulose.

FIG. 4 is a graph showing the relationship between the amount of dropped NaOH and pH for fibrous cellulose-containing slurry having a phosphorous acid group as an ionic substituent. The amount of phosphorus oxoacid groups introduced into fibrous cellulose is measured, for example, as follows.
First, a slurry containing fibrous cellulose is treated with a strongly acidic ion exchange resin. In addition, before the treatment with the strongly acidic ion exchange resin, a defibration treatment similar to the fibrillation treatment step described below may be performed on the object to be measured, if necessary.
Next, the change in pH is observed while adding sodium hydroxide aqueous solution, and a titration curve as shown in the upper part of FIG. 4 is obtained. The titration curve shown in the upper part of FIG. 4 plots the measured pH against the amount of alkali added, and the titration curve shown in the lower part of FIG. 4 plots the pH against the amount of alkali added. The increment (differential value) (1/mmol) is plotted. In this neutralization titration, two points where the increment (the differential value of the pH with respect to the amount of alkali dropped) are maximized are confirmed in the curve obtained by plotting the measured pH against the amount of alkali added. Among these, the maximum point of the increment obtained first when the alkali is first added is called the first end point, and the maximum point of the increment obtained next is called the second end point. The amount of alkali required from the start of titration to the first end point is equal to the first dissociated acid amount of fibrous cellulose contained in the slurry used for titration, and the amount of alkali required from the first end point to the second end point The amount is equal to the second dissociated acid amount of fibrous cellulose contained in the slurry used for titration, and the amount of alkali required from the start of titration to the second end point is equal to the amount of fibrous cellulose contained in the slurry used for titration. equal to the total dissociated acid content of A value obtained by dividing the amount of alkali required from the start of titration to the first end point by the solid content (g) in the slurry to be titrated is the amount of phosphorus oxoacid group introduced (mmol/g). In addition, when simply referring to the amount of phosphorus oxoacid groups introduced (or the amount of phosphorus oxoacid groups), it means the amount of the first dissociated acid.
In FIG. 4, the region from the start of titration to the first end point is called the first region, and the region from the first end point to the second end point is called the second region. For example, when the phosphoric acid group is a phosphoric acid group and the phosphoric acid group causes condensation, the weakly acidic group amount (second dissociated acid amount) in the phosphoric acid group is apparently decreased, and the first region The amount of alkali required for the second region is less than the amount of alkali required for the second region. On the other hand, the amount of strongly acidic groups (the amount of first dissociated acid) in the phosphorus oxoacid group coincides with the amount of phosphorus atoms regardless of the presence or absence of condensation. In addition, when the phosphorous acid group is a phosphorous acid group, the weakly acidic group does not exist in the phosphorous acid group, so the amount of alkali required for the second region is reduced, or the amount of alkali required for the second region is may be zero. In this case, the titration curve has one point at which the pH increment is maximum.

In addition, since the denominator of the amount of introduced phosphate groups (mmol/g) indicates the mass of the acid-form fibrous cellulose, the amount of phosphate groups possessed by the acid-form fibrous cellulose (hereinafter referred to as the phosphate group amount (acid form)). On the other hand, when the counter ion of the phosphooxy acid group is substituted with an arbitrary cation C so as to have a charge equivalent, the denominator is converted to the mass of fibrous cellulose when the cation C is the counter ion. Thus, the amount of phosphate groups (hereinafter referred to as the amount of phosphate groups (type C)) possessed by fibrous cellulose whose counter ion is cation C can be determined.
That is, it is calculated by the following formula.
Phosphorus oxo acid group amount (C type) = Phosphorus oxo acid group amount (acid type) / {1 + (W-1) × A / 1000}
A [mmol/g]: Total amount of anions derived from phosphate groups possessed by fibrous cellulose (total dissociated acid amount of phosphate groups)
W: Formula weight per valence of cation C (for example, 23 for Na and 9 for Al)

FIG. 5 is a graph showing the relationship between the amount of dropped NaOH and pH for a dispersion containing fibrous cellulose having a carboxyl group as an ionic substituent. The amount of carboxyl groups introduced into fibrous cellulose is measured, for example, as follows.
First, a dispersion containing fibrous cellulose is treated with a strongly acidic ion exchange resin. In addition, before the treatment with the strongly acidic ion exchange resin, a defibration treatment similar to the fibrillation treatment step described below may be performed on the object to be measured, if necessary.
Then, while adding sodium hydroxide aqueous solution, the change in pH is observed to obtain a titration curve as shown in the upper part of FIG. The titration curve shown in the upper part of FIG. 5 plots the measured pH against the amount of alkali added, and the titration curve shown in the lower part of FIG. 5 plots the pH against the amount of alkali added. The increment (differential value) (1/mmol) is plotted. In this neutralization titration, in the curve plotting the measured pH against the amount of alkali added, one point where the increment (the differential value of pH with respect to the amount of alkali dropped) is maximum was confirmed. 1 end point. Here, the region from the start of titration to the first end point in FIG. 5 is called the first region. The amount of alkali required in the first region is equal to the amount of carboxyl groups in the dispersion used for titration. Then, the amount of alkali (mmol) required in the first region of the titration curve is divided by the solid content (g) in the dispersion containing the fibrous cellulose to be titrated to obtain the amount of carboxyl groups introduced (mmol / g).

In addition, since the denominator of the amount of introduced carboxy groups (mmol/g) is the mass of the acid-type fibrous cellulose, the amount of carboxy groups possessed by the acid-type fibrous cellulose (hereinafter referred to as the amount of carboxy groups (acid-type )). On the other hand, when the counterion of the carboxy group is substituted with an arbitrary cation C so as to have a charge equivalent, the denominator is converted to the mass of fibrous cellulose when the cation C is the counterion. , the amount of carboxy groups (hereinafter referred to as the amount of carboxy groups (C type)) possessed by fibrous cellulose whose counter ion is cation C can be obtained. That is, it is calculated by the following formula.
Carboxy group amount (C type) = carboxy group amount (acid form) / {1 + (W-1) x (carboxy group amount (acid form)) / 1000}
W: Formula weight per valence of cation C (for example, 23 for Na and 9 for Al)

When measuring the amount of ionic substituents by the titration method, if the amount of 1 drop of aqueous sodium hydroxide solution is too large, or if the titration interval is too short, the amount of ionic substituents will be lower than the original value. may not be obtained. As a suitable drop amount and titration interval, for example, it is desirable to titrate 10 to 50 μL of 0.1N sodium hydroxide aqueous solution every 5 to 30 seconds. In order to eliminate the influence of carbon dioxide dissolved in the fibrous cellulose-containing slurry, for example, it is desirable to measure while blowing an inert gas such as nitrogen gas into the slurry from 15 minutes before the start of titration to the end of titration.

<Manufacturing process of fine fibrous cellulose>
<Textile raw material>
Microfibrous cellulose is produced from fibrous raw materials containing cellulose. The fibrous raw material containing cellulose is not particularly limited, but pulp is preferably used because it is readily available and inexpensive. Pulp includes, for example, wood pulp, non-wood pulp, and deinked pulp. Examples of wood pulp include, but are not limited to, hardwood kraft pulp (LBKP), softwood kraft pulp (NBKP), sulfite pulp (SP), dissolving pulp (DP), soda pulp (AP), unbleached kraft pulp (UKP). ) and chemical pulp such as oxygen bleached kraft pulp (OKP), semi-chemical pulp such as semi-chemical pulp (SCP) and chemigroundwood pulp (CGP), groundwood pulp (GP) and thermomechanical pulp (TMP, BCTMP) A mechanical pulp etc. are mentioned. Non-wood pulps include, but are not limited to, cotton-based pulps such as cotton linters and cotton lints, and non-wood-based pulps such as hemp, straw, and bagasse. The deinked pulp is not particularly limited, but includes, for example, deinked pulp made from waste paper. The pulp of this embodiment may be used alone or in combination of two or more. Among the above pulps, wood pulp and deinked pulp are preferred, for example, from the viewpoint of availability. In addition, among wood pulps, the cellulose ratio is high and the yield of fine fibrous cellulose at the time of defibration is high, and the decomposition of cellulose in the pulp is small, and fine fibrous cellulose of long fibers with a large axial ratio can be obtained. From the point of view, for example, chemical pulp is more preferable, and kraft pulp and sulfite pulp are more preferable. The use of fine fibrous cellulose of long fibers with a large axial ratio tends to increase the viscosity.

As the fiber raw material containing cellulose, for example, cellulose contained in sea squirts and bacterial cellulose produced by acetic acid bacteria can be used. Fibers formed by straight-chain nitrogen-containing polysaccharide polymers such as chitin and chitosan can also be used instead of fiber raw materials containing cellulose.

<Phosphorus oxoacid group introduction step>
The process for producing fine fibrous cellulose preferably includes an ionic substituent introduction process, and examples of the ionic substituent introduction process include a phosphorus oxoacid group introduction process. In the phosphorus oxoacid group-introducing step, at least one compound selected from compounds capable of introducing a phosphorus oxoacid group (hereinafter also referred to as "compound A") is added to cellulose by reacting with a hydroxyl group possessed by a fiber raw material containing cellulose. It is a step of acting on a fiber raw material containing. Through this step, the phosphate group-introduced fiber is obtained.

In the phosphorus oxoacid group-introducing step according to the present embodiment, the reaction between the fiber material containing cellulose and compound A is performed in the presence of at least one selected from urea and derivatives thereof (hereinafter also referred to as "compound B"). may On the other hand, the reaction between the cellulose-containing fiber raw material and the compound A may be carried out in the absence of the compound B.

An example of the method of allowing the compound A to act on the fiber raw material in the presence of the compound B includes a method of mixing the compound A and the compound B with the fiber raw material in a dry state, a wet state, or a slurry state. Among these, it is preferable to use a fiber raw material in a dry state or a wet state, and it is particularly preferable to use a fiber raw material in a dry state, because the uniformity of the reaction is high. Although the form of the fiber material is not particularly limited, it is preferably in the form of cotton or a thin sheet, for example. The compound A and the compound B can be added to the fiber raw material in the form of a powder, a solution dissolved in a solvent, or a melted state by heating to a melting point or higher. Among these, it is preferable to add in the form of a solution dissolved in a solvent, particularly in the form of an aqueous solution, since the uniformity of the reaction is high. Moreover, the compound A and the compound B may be added simultaneously to the fiber raw material, may be added separately, or may be added as a mixture. The method for adding the compound A and the compound B is not particularly limited, but when the compound A and the compound B are in the form of a solution, the fiber raw material may be immersed in the solution to absorb the liquid and then taken out, or the fiber raw material may be taken out. The solution may be added dropwise to the Further, the necessary amount of compound A and compound B may be added to the fiber raw material, or after adding excessive amounts of compound A and compound B to the fiber raw material, the excess compound A and compound B are removed by pressing or filtering. may be removed.

The compound A used in the present embodiment may be any compound having a phosphorus atom and capable of forming an ester bond with cellulose. Salts, phosphoric anhydride (diphosphorus pentoxide) and the like can be mentioned, but are not particularly limited. Phosphoric acid of various purities can be used, for example, 100% phosphoric acid (orthophosphoric acid) or 85% phosphoric acid can be used. Phosphorous acid includes 99% phosphorous acid (phosphonic acid). Dehydration-condensed phosphoric acid is obtained by condensing two or more molecules of phosphoric acid by dehydration reaction, and examples thereof include pyrophosphoric acid and polyphosphoric acid. Phosphates, phosphites and dehydrated condensed phosphates include lithium salts, sodium salts, potassium salts and ammonium salts of phosphoric acid, phosphorous acid or dehydrated condensed phosphoric acids. It can be a degree of harmony. Among these, the introduction efficiency of the phosphate group is high, the fibrillation efficiency is easily improved in the fibrillation step described later, the cost is low, and it is easy to apply industrially. salt, potassium phosphate, ammonium phosphate or phosphorous acid, sodium phosphite, potassium phosphite, ammonium phosphite, phosphoric acid, sodium dihydrogen phosphate, More preferred are disodium hydrogen phosphate, ammonium dihydrogen phosphate, phosphorous acid, and sodium phosphite.

The amount of compound A added to the fiber raw material is not particularly limited. For example, when the amount of compound A added is converted to the phosphorus atomic weight, the amount of phosphorus atoms added to the fiber raw material (absolute dry mass) is 0.5% by mass or more. It is preferably 100% by mass or less, more preferably 1% by mass or more and 50% by mass or less, and even more preferably 2% by mass or more and 30% by mass or less. By setting the amount of phosphorus atoms added to the fiber raw material within the above range, the yield of fine fibrous cellulose can be further improved. On the other hand, by setting the amount of phosphorus atoms added to the fiber raw material to be equal to or less than the above upper limit, it is possible to balance the effect of improving the yield and the cost.

Compound B used in this embodiment is at least one selected from urea and derivatives thereof as described above. Compound B includes, for example, urea, biuret, 1-phenylurea, 1-benzylurea, 1-methylurea, and 1-ethylurea.
From the viewpoint of improving the uniformity of the reaction, compound B is preferably used as an aqueous solution. From the viewpoint of further improving the uniformity of the reaction, it is preferable to use an aqueous solution in which both compound A and compound B are dissolved.

The amount of compound B added to the fiber raw material (absolute dry mass) is not particularly limited, but is preferably 1% by mass or more and 500% by mass or less, more preferably 10% by mass or more and 400% by mass or less, More preferably, it is 100% by mass or more and 350% by mass or less.

In the reaction between the fiber raw material containing cellulose and compound A, in addition to compound B, for example, amides or amines may be included in the reaction system. Examples of amides include formamide, dimethylformamide, acetamide, dimethylacetamide and the like. Examples of amines include methylamine, ethylamine, trimethylamine, triethylamine, monoethanolamine, diethanolamine, triethanolamine, pyridine, ethylenediamine and hexamethylenediamine. Among these, triethylamine in particular is known to work as a good reaction catalyst.

In the phosphorus oxoacid group-introducing step, it is preferable to heat-treat the fiber raw material after adding or mixing the compound A or the like to the fiber raw material. As the heat treatment temperature, it is preferable to select a temperature that can efficiently introduce phosphorus oxoacid groups while suppressing thermal decomposition and hydrolysis reaction of the fiber. The heat treatment temperature is, for example, preferably 50° C. or higher and 300° C. or lower, more preferably 100° C. or higher and 250° C. or lower, and even more preferably 130° C. or higher and 200° C. or lower. In addition, for the heat treatment, equipment having various heat media can be used, for example, a stirring dryer, a rotary dryer, a disk dryer, a roll heater, a plate heater, a fluidized bed dryer, and a band dryer. A mold drying device, a filter drying device, a vibrating fluidized drying device, a flash drying device, a vacuum drying device, an infrared heating device, a far infrared heating device, a microwave heating device, and a high frequency drying device can be used.

In the heat treatment according to the present embodiment, for example, the compound A is added to a thin sheet-like fiber raw material by a method such as impregnation, and then heated, or the fiber raw material and the compound A are heated while kneading or stirring with a kneader or the like. method can be adopted. This makes it possible to suppress unevenness in the concentration of the compound A in the fiber raw material, and to more uniformly introduce the phosphorous acid groups to the surface of the cellulose fibers contained in the fiber raw material. This is because when water molecules move to the surface of the fiber material during drying, the dissolved compound A is attracted to the water molecules by surface tension and similarly moves to the surface of the fiber material (that is, the concentration unevenness of the compound A is It is thought that this is due to the fact that it is possible to suppress the occurrence of

In addition, the heating device used for the heat treatment always removes the moisture retained by the slurry and the moisture generated due to the dehydration condensation (phosphorylation) reaction between the compound A and the hydroxyl groups contained in the cellulose etc. in the fiber raw material. It is preferable that the device can be discharged to the outside of the device system. As such a heating device, for example, an air-blowing oven can be used. By constantly draining the water in the device system, it is possible to suppress the hydrolysis reaction of the phosphate ester bond, which is the reverse reaction of phosphorylation, and to suppress the acid hydrolysis of the sugar chains in the fiber. can. Therefore, it is possible to obtain fine fibrous cellulose having a high axial ratio.

The heat treatment time is, for example, preferably 1 second or more and 300 minutes or less, more preferably 1 second or more and 1000 seconds or less, and 10 seconds or more and 800 seconds or less, after water is substantially removed from the fiber raw material. is more preferable. In the present embodiment, the amount of phosphorus oxoacid groups to be introduced can be set within a preferable range by setting the heating temperature and the heating time within appropriate ranges.

The phosphorus oxoacid group-introducing step may be performed at least once, but may be performed repeatedly two or more times. By performing the phosphorus oxoacid group-introducing step two or more times, many phosphorus oxoacid groups can be introduced into the fiber raw material. In the present embodiment, as an example of a preferred aspect, the case where the step of introducing a phosphorus oxoacid group is performed twice is mentioned.

The amount of phosphorus oxoacid groups introduced into the fiber raw material is, for example, preferably 0.10 mmol/g or more, more preferably 0.20 mmol/g or more, more preferably 0.50 mmol/g per 1 g (mass) of fine fibrous cellulose. g or more is more preferable, and 1.00 mmol/g or more is particularly preferable. In addition, the amount of phosphorus oxoacid groups introduced into the fiber raw material is, for example, preferably 5.20 mmol/g or less, more preferably 3.65 mmol/g or less per 1 g (mass) of fine fibrous cellulose. It is more preferably 00 mmol/g or less. By setting the amount of the phosphorus oxoacid group to be introduced within the above range, the fiber raw material can be easily made finer, and the stability of the fine fibrous cellulose can be enhanced.

<Carboxy Group Introduction Step>
The production process of fine fibrous cellulose may include, for example, a carboxyl group introduction process as an ionic substituent introduction process. In the step of introducing a carboxy group, the fiber raw material containing cellulose is subjected to oxidation treatment such as ozone oxidation, oxidation by the Fenton method, TEMPO oxidation treatment, a compound having a carboxylic acid-derived group or a derivative thereof, or a carboxylic acid-derived group. This is done by treating the compound with an acid anhydride or a derivative thereof.

The compound having a carboxylic acid-derived group is not particularly limited. Examples include tricarboxylic acid compounds. Derivatives of compounds having a carboxylic acid-derived group are not particularly limited, but include, for example, imidized acid anhydrides of compounds having a carboxy group and derivatives of acid anhydrides of compounds having a carboxy group. Examples of imidized acid anhydrides of compounds having a carboxyl group include, but are not particularly limited to, imidized dicarboxylic acid compounds such as maleimide, succinimide and phthalimide.

The acid anhydride of the compound having a group derived from carboxylic acid is not particularly limited. acid anhydrides; In addition, the acid anhydride derivative of the compound having a group derived from carboxylic acid is not particularly limited. Acid anhydrides in which at least some of the hydrogen atoms are substituted with substituents such as alkyl groups and phenyl groups can be mentioned.

In the carboxyl group introduction step, when the TEMPO oxidation treatment is performed, it is preferable to perform the treatment under the condition of pH 6 or more and 8 or less. Such treatment is also referred to as neutral TEMPO oxidation treatment. Neutral TEMPO oxidation treatment includes, for example, sodium phosphate buffer (pH=6.8), pulp as a fiber raw material, and TEMPO (2,2,6,6-tetramethylpiperidine-1-oxyl) as a catalyst. This can be done by adding sodium hypochlorite as a nitroxy radical, sacrificial reagent. Furthermore, coexistence of sodium chlorite enables efficient oxidation of aldehydes generated in the process of oxidation to carboxyl groups. Moreover, the TEMPO oxidation treatment may be performed under the condition that the pH is 10 or more and 11 or less. Such treatment is also called alkali TEMPO oxidation treatment. Alkaline TEMPO oxidation treatment can be performed, for example, by adding a nitroxy radical such as TEMPO as a catalyst, sodium bromide as a cocatalyst, and sodium hypochlorite as an oxidizing agent to pulp as a fiber raw material. .

The amount of carboxyl groups to be introduced into the fiber raw material varies depending on the type of substituent. For example, when carboxyl groups are introduced by TEMPO oxidation, the amount is preferably 0.10 mmol/g or more per 1 g (mass) of fine fibrous cellulose. , is more preferably 0.20 mmol/g or more, still more preferably 0.50 mmol/g or more, and particularly preferably 0.90 mmol/g or more. Also, it is preferably 2.5 mmol/g or less, more preferably 2.20 mmol/g or less, and even more preferably 2.00 mmol/g or less. In addition, when the substituent is a carboxymethyl group, it may be 5.8 mmol/g or less per 1 g (mass) of fine fibrous cellulose.

<Washing process>
In the method for producing fine fibrous cellulose according to the present embodiment, the ionic substituent-introduced fiber can be subjected to a washing step, if necessary. The washing step is performed by washing the ionic substituent-introduced fiber with, for example, water or an organic solvent. Further, the washing step may be performed after each step described later, and the number of washings performed in each washing step is not particularly limited.

<Alkali treatment process>
When producing fine fibrous cellulose, the fiber raw material may be subjected to alkali treatment between the ionic substituent introduction step and the fibrillation treatment step described later. The method of alkali treatment is not particularly limited, but includes, for example, a method of immersing the ionic substituent-introduced fiber in an alkali solution.

The alkaline compound contained in the alkaline solution is not particularly limited, and may be an inorganic alkaline compound or an organic alkaline compound. In the present embodiment, it is preferable to use, for example, sodium hydroxide or potassium hydroxide as the alkaline compound because of its high versatility. Moreover, the solvent contained in the alkaline solution may be either water or an organic solvent. Among them, the solvent contained in the alkaline solution is preferably water or a polar solvent including a polar organic solvent exemplified by alcohol, and more preferably an aqueous solvent including at least water. As the alkaline solution, for example, an aqueous sodium hydroxide solution or an aqueous potassium hydroxide solution is preferable because of its high versatility.

Although the temperature of the alkaline solution in the alkaline treatment step is not particularly limited, it is preferably 5° C. or higher and 80° C. or lower, more preferably 10° C. or higher and 60° C. or lower. The immersion time of the ionic substituent-introduced fiber in the alkali solution in the alkali treatment step is not particularly limited, but is preferably 5 minutes or more and 30 minutes or less, more preferably 10 minutes or more and 20 minutes or less. The amount of the alkaline solution used in the alkaline treatment is not particularly limited, but for example, it is preferably 100% by mass or more and 100000% by mass or less, and 1000% by mass or more and 10000% by mass with respect to the absolute dry mass of the ionic substituent-introduced fiber. The following are more preferable.

In order to reduce the amount of alkaline solution used in the alkaline treatment step, the ionic substituent-introduced fiber may be washed with water or an organic solvent after the ionic substituent-introducing step and before the alkaline treatment step. After the alkali treatment step and before the fibrillation treatment step, it is preferable to wash the alkali-treated ionic substituent-introduced fibers with water or an organic solvent from the viewpoint of improving handleability.

<Acid treatment step>
When producing fine fibrous cellulose, the fiber raw material may be subjected to an acid treatment between the step of introducing an ionic substituent and the later-described fibrillation treatment step. For example, an ionic substituent introduction step, an acid treatment, an alkali treatment and a fibrillation treatment may be performed in this order.

The acid treatment method is not particularly limited, but includes, for example, a method of immersing the fiber raw material in an acidic liquid containing an acid. Although the concentration of the acid liquid used is not particularly limited, it is preferably 10% by mass or less, more preferably 5% by mass or less. Moreover, the pH of the acidic liquid to be used is not particularly limited. Examples of acids contained in the acid solution include inorganic acids, sulfonic acids, and carboxylic acids. Examples of inorganic acids include sulfuric acid, nitric acid, hydrochloric acid, hydrobromic acid, hydroiodic acid, hypochlorous acid, chlorous acid, chloric acid, perchloric acid, phosphoric acid and boric acid. Examples of sulfonic acid include methanesulfonic acid, ethanesulfonic acid, benzenesulfonic acid, p-toluenesulfonic acid, trifluoromethanesulfonic acid and the like. Carboxylic acids include, for example, formic acid, acetic acid, citric acid, gluconic acid, lactic acid, oxalic acid, and tartaric acid. Among these, it is particularly preferable to use hydrochloric acid or sulfuric acid.

The temperature of the acid solution in the acid treatment is not particularly limited. The immersion time in the acid solution in the acid treatment is not particularly limited, but is preferably 5 minutes or more and 120 minutes or less, more preferably 10 minutes or more and 60 minutes or less. The amount of the acid solution used in the acid treatment is not particularly limited. is more preferred.

<Fibrillation treatment>
By defibrating the ionic substituent-introduced fibers in the fibrillation treatment step, fine fibrous cellulose can be obtained. In the defibration treatment process, for example, a fibrillation treatment device can be used. The fibrillation treatment device is not particularly limited, but for example, a high-speed fibrillator, a grinder (stone mill type pulverizer), a high pressure homogenizer, an ultra-high pressure homogenizer, a high pressure impact type pulverizer, a ball mill, a bead mill, a disk refiner, a conical refiner, and a biaxial refiner. A kneader, a vibration mill, a homomixer under high-speed rotation, an ultrasonic disperser, a beater, or the like can be used. Among the above defibration equipment, it is more preferable to use a high-speed fibrillation machine, a high-pressure homogenizer, and an ultrahigh-pressure homogenizer, which are less affected by the grinding media and less likely to cause contamination.

In the fibrillation treatment step, for example, the ionic substituent-introduced fibers are preferably diluted with a dispersion medium to form a slurry. As the dispersion medium, one or more selected from organic solvents such as water and polar organic solvents can be used. The polar organic solvent is not particularly limited, but alcohols, polyhydric alcohols, ketones, ethers, esters, aprotic polar solvents and the like are preferable. Examples of alcohols include methanol, ethanol, isopropanol, n-butanol, isobutyl alcohol and the like. Examples of polyhydric alcohols include ethylene glycol, propylene glycol and glycerin. Ketones include acetone, methyl ethyl ketone (MEK), and the like. Examples of ethers include diethyl ether, tetrahydrofuran, ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, ethylene glycol mono-n-butyl ether, propylene glycol monomethyl ether and the like. Examples of esters include ethyl acetate and butyl acetate. Aprotic polar solvents include dimethylsulfoxide (DMSO), dimethylformamide (DMF), dimethylacetamide (DMAc), N-methyl-2-pyrrolidinone (NMP) and the like.

The solid content concentration of the fine fibrous cellulose at the defibration treatment can be appropriately set. Further, the slurry obtained by dispersing the ionic substituent-introduced fiber in the dispersion medium may contain a solid content other than the ionic substituent-introduced fiber, such as urea having hydrogen bonding properties.

<Optional component>
The base layer may contain optional ingredients other than the fine fibrous cellulose. Optional components include, for example, hydrophilic polymers and organic ions. Among them, the base layer is preferably a layer further containing a hydrophilic polymer.

The hydrophilic polymer is preferably a hydrophilic oxygen-containing organic compound (excluding the above cellulose fibers). In this case, the oxygen-containing organic compound is particularly preferably a hydrophilic organic compound. A hydrophilic oxygen-containing organic compound can improve the strength, density, chemical resistance, etc. of the base layer. The hydrophilic oxygen-containing organic compound preferably has an SP value of, for example, 9.0 or more. Further, the hydrophilic oxygen-containing organic compound is preferably such that 1 g or more of the oxygen-containing organic compound dissolves in 100 ml of deionized water, for example.

Examples of oxygen-containing organic compounds include polyethylene glycol, polyethylene oxide, casein, dextrin, starch, modified starch, polyvinyl alcohol, modified polyvinyl alcohol (such as acetoacetylated polyvinyl alcohol), polyethylene oxide, polyvinyl pyrrolidone, polyvinyl methyl ether, polyvinyl methyl ether, Hydrophilic polymers such as acrylates, polyacrylamide, acrylic acid alkyl ester copolymers, urethane copolymers, cellulose derivatives (hydroxyethyl cellulose, carboxyethyl cellulose, carboxymethyl cellulose, etc.); hydrophilic polymers such as glycerin, sorbitol, ethylene glycol and low-molecular-weight compounds. Among these, from the viewpoint of improving the strength, density, chemical resistance, etc. of the base layer, it is preferably at least one selected from polyethylene glycol, polyethylene oxide and polyvinyl alcohol, and more preferably polyethylene glycol.

The weight average molecular weight of the hydrophilic polymer may be 10,000 or more, preferably 50,000 or more, and more preferably 100,000 or more. Also, the weight average molecular weight of the hydrophilic polymer is preferably 8,000,000 or less, more preferably 5,000,000 or less.

The content of the hydrophilic polymer is preferably 5% by mass or more, more preferably 10% by mass, even more preferably 15% by mass or more, and 20% by mass, relative to the total mass of the base layer. % or more is particularly preferable. The content of the hydrophilic polymer is preferably 70% by mass or less, more preferably 60% by mass or less, and even more preferably 50% by mass or less, relative to the total mass of the base layer. . By setting the content of the hydrophilic polymer within the above range, it is possible to form a pattern-forming substrate having high strength and high transparency.

(Other layers)
The pattern forming substrate may have an adhesive layer between the resin layer and the base layer. Examples of the adhesive that constitutes the adhesive layer include acrylic resins. Examples of adhesives other than acrylic resins include vinyl chloride resins, (meth)acrylic acid ester resins, styrene/acrylic acid ester copolymer resins, vinyl acetate resins, and vinyl acetate/(meth)acrylic acid ester copolymer resins. Polymer resins, urethane resins, silicone resins, epoxy resins, ethylene/vinyl acetate copolymer resins, polyester resins, polyvinyl alcohol resins, ethylene vinyl alcohol copolymer resins, and rubber emulsions such as SBR and NBR. be done.

(Method for producing pattern-forming substrate)
A method for producing a pattern-forming base material may include the steps of forming a base layer containing fibrous cellulose having a fiber width of 1000 nm or less, and coating a resin composition on the base layer. At this time, the resin composition may contain optional components such as an adhesion aid, if necessary.
Further, the method for producing a pattern forming base material may include the steps of forming a base layer containing fibrous cellulose with a fiber width of 1000 nm or less and laminating a resin film or resin sheet on the base layer.

The step of forming a base layer containing fibrous cellulose with a fiber width of 1000 nm or less includes obtaining a sheet-forming composition (hereinafter also referred to as slurry or coating solution) containing fibrous cellulose with a fiber width of 1000 nm or less; A coating step of applying the sheet-forming composition onto a substrate or a paper-making step of paper-making the sheet-forming composition is included. As a result, the sheet described above is obtained. The sheet-forming composition is preferably a composition containing a hydrophilic polymer as described above.

<Coating process>
In the coating step, for example, a sheet-forming composition (slurry) containing fibrous cellulose is applied onto a substrate, dried, and the formed sheet is peeled off from the substrate to obtain a sheet. can. In addition, sheets can be continuously produced by using a coating device and a long base material.

The material of the base material used in the coating step is not particularly limited, but a material having high wettability with respect to the sheet-forming composition (slurry) may suppress shrinkage of the sheet during drying. It is preferable to choose one from which the subsequently formed sheet can be easily peeled off. Among them, a resin film or plate or a metal film or plate is preferable, but is not particularly limited. For example, resin films and plates such as polypropylene, acrylic, polyethylene terephthalate, vinyl chloride, polystyrene, polycarbonate, and polyvinylidene chloride, metal films and plates such as aluminum, zinc, copper, and iron plates, and those whose surfaces have been oxidized. , a stainless steel film or plate, a brass film or plate, or the like can be used.

In the coating process, when the viscosity of the slurry is low and it spreads on the base material, a dam frame is fixed on the base material in order to obtain a sheet with a predetermined thickness and basis weight. may The frame for damming is not particularly limited, but it is preferable to select, for example, one that allows easy peeling of the edge of the sheet that adheres after drying. From such a point of view, a molded resin plate or metal plate is more preferable. In this embodiment, for example, resin plates such as polypropylene plates, acrylic plates, polyethylene terephthalate plates, vinyl chloride plates, polystyrene plates, polycarbonate plates, and polyvinylidene chloride plates, and metal plates such as aluminum plates, zinc plates, copper plates, iron plates, etc. , and those whose surfaces have been oxidized, and those obtained by molding a stainless steel plate, a brass plate, or the like can be used.
The coating machine for coating the slurry on the base material is not particularly limited, but for example, a roll coater, gravure coater, die coater, curtain coater, air doctor coater, etc. can be used. A die coater, a curtain coater, and a spray coater are particularly preferred because they can make the thickness of the sheet more uniform.

The slurry temperature and the ambient temperature when the slurry is applied to the substrate are not particularly limited, but are preferably 5° C. or higher and 80° C. or lower, more preferably 10° C. or higher and 60° C. or lower, and 15° C. It is more preferably 50° C. or higher, and particularly preferably 20° C. or higher and 40° C. or lower. If the coating temperature is at least the above lower limit, the slurry can be more easily coated. When the coating temperature is equal to or lower than the above upper limit, volatilization of the dispersion medium during coating can be suppressed.

In the coating step, the slurry is applied so that the finished basis weight of the sheet is preferably 10 g/m ² or more and 100 g/m ² or less, more preferably 20 g/m ² or more and 60 g/m ² or less. It is preferable to apply it to the material. By coating so that the basis weight is within the above range, a sheet having more excellent strength can be obtained.

The coating step includes the step of drying the slurry applied onto the substrate, as described above. The step of drying the slurry is not particularly limited, but may be performed by, for example, a non-contact drying method, a method of drying while restraining the sheet, or a combination thereof.

The non-contact drying method is not particularly limited, but for example, a method of drying by heating with hot air, infrared rays, far infrared rays, or near infrared rays (heat drying method), or a method of drying in a vacuum (vacuum drying method) is applied. can do. Although the heat drying method and the vacuum drying method may be combined, the heat drying method is usually applied. Drying with infrared rays, far-infrared rays, or near-infrared rays is not particularly limited.

The heating temperature in the heat drying method is not particularly limited, but is preferably 20° C. or higher and 150° C. or lower, more preferably 25° C. or higher and 105° C. or lower. If the heating temperature is equal to or higher than the above lower limit, the dispersion medium can be rapidly volatilized. Moreover, if the heating temperature is equal to or lower than the above upper limit, it is possible to suppress the cost required for heating and suppress discoloration of fibrous cellulose due to heat.

<Papermaking process>
The papermaking process is performed by papermaking the slurry using a papermaking machine. The paper machine used in the papermaking process is not particularly limited, but examples thereof include continuous paper machines such as fourdrinier, cylinder, and inclined paper machines, and multi-layer paper machines combining these. In the paper-making process, a known paper-making method such as hand-making may be employed.

The papermaking process is carried out by filtering the slurry with a wire and dehydrating it to obtain a wet paper sheet, which is then pressed and dried. The filter cloth used for filtering and dewatering the slurry is not particularly limited, but it is more preferable that, for example, fibrous cellulose does not pass through and the filtration rate does not become too slow. Although such filter cloth is not particularly limited, for example, sheets, fabrics, and porous membranes made of organic polymers are preferable. Although the organic polymer is not particularly limited, non-cellulose organic polymers such as polyethylene terephthalate, polyethylene, polypropylene, and polytetrafluoroethylene (PTFE) are preferred. In this embodiment, for example, a polytetrafluoroethylene porous film having a pore size of 0.1 μm or more and 20 μm or less, or a polyethylene terephthalate or polyethylene fabric having a pore size of 0.1 μm or more and 20 μm or less can be used.

In the sheeting step, a method for producing a sheet from a slurry includes, for example, a squeezing section that discharges a slurry containing fibrous cellulose onto the upper surface of an endless belt and squeezes a dispersion medium out of the discharged slurry to form a web. , a drying section for drying the web to form a sheet. An endless belt is provided from the water squeezing section to the drying section, and the web produced in the water squeezing section is conveyed to the drying section while being placed on the endless belt.

The dehydration method used in the papermaking process is not particularly limited, but includes, for example, dehydration methods commonly used in the manufacture of paper. Among these, the method of dehydrating with a fourdrinier, a circular net, an inclined wire, or the like and then further dehydrating with a roll press is preferable. The drying method used in the papermaking process is not particularly limited, but includes, for example, methods used in the manufacture of paper. Among these, a drying method using a cylinder dryer, Yankee dryer, hot air drying, near-infrared heater, infrared heater, or the like is more preferable.

A substrate for pattern formation can be obtained by coating a resin composition on the base layer thus obtained, or laminating a resin film or a resin sheet.

EXAMPLES The characteristics of the present invention will be described more specifically below with reference to examples and comparative examples. The materials, amounts used, proportions, treatment details, treatment procedures, etc. shown in the following examples can be changed as appropriate without departing from the gist of the present invention. Therefore, the scope of the present invention should not be construed to be limited by the specific examples shown below.

<Production Example 1>
<Phosphorus oxo oxidation treatment>
As raw material pulp, softwood kraft pulp manufactured by Oji Paper Co., Ltd. (solid content 93% by mass, basis weight 208 g / m ² sheet, defiberized and Canadian standard freeness (CSF) measured according to JIS P 8121 700 ml) It was used. The raw material pulp was subjected to phosphorus oxo oxidation treatment as follows. First, a mixed aqueous solution of ammonium dihydrogen phosphate and urea is added to 100 parts by mass (absolute dry mass) of the raw material pulp to obtain 45 parts by mass of ammonium dihydrogen phosphate, 120 parts by mass of urea, and 150 parts by mass of water. A chemical-impregnated pulp was obtained by adjusting as follows. Next, the resulting chemical solution-impregnated pulp was heated in a hot air dryer at 165° C. for 200 seconds to introduce phosphate groups into the cellulose in the pulp to obtain phosphorylated pulp.

<Washing treatment>
Then, the obtained phosphorylated pulp was washed. In the washing treatment, a pulp dispersion liquid obtained by pouring 10 L of ion-exchanged water into 100 g (absolute dry mass) of phosphorylated pulp is stirred so that the pulp is uniformly dispersed, and then filtration and dehydration are repeated. went. The washing was finished when the electric conductivity of the filtrate became 100 μS/cm or less.

<Neutralization treatment>
The washed phosphorylated pulp was further subjected to the above phosphorus oxo-oxidation treatment and the washing treatment once in this order. Next, the washed phosphorylated pulp was neutralized as follows. First, the washed phosphorylated pulp was diluted with 10 L of ion-exchanged water, and then a 1N sodium hydroxide aqueous solution was added little by little while stirring to obtain a phosphorylated pulp slurry having a pH of 12 or more and 13 or less. . Next, the phosphorylated pulp slurry was dehydrated to obtain neutralized phosphorylated pulp.

The phosphorus oxyoxidized pulp thus obtained was subjected to infrared absorption spectrum measurement using FT-IR. As a result, an absorption based on P=O of the phosphate group was observed near 1230 cm ^-1 , confirming that the phosphate group was added to the pulp. In addition, when the obtained phosphorylated pulp was tested and analyzed with an X-ray diffraction device, it was found that the A typical peak was confirmed, confirming that it had cellulose type I crystals.

<Mechanical treatment>
Ion-exchanged water was added to the obtained dehydrated sheet of twice-phosphorylated cellulose to prepare a slurry having a solid content concentration of 2% by mass. This slurry was treated three times at a pressure of 245 MPa with a wet-type atomizer (manufactured by Sugino Machine Co., Ltd., Ultimizer) to obtain a fine fibrous cellulose dispersion. X-ray diffraction confirmed that this fine fibrous cellulose maintained cellulose type I crystals. Further, when the fiber width of the fine fibrous cellulose was measured using a transmission electron microscope, it was 3 to 5 nm. In addition, <measurement of the amount of substituents> described later
was 2.00 mmol/g. The total amount of dissociated acid was 3.30 mol/g.

<Measurement of the amount of substituents>
The phosphorus oxoacid group content (strongly acidic group content) was prepared by diluting a fine fibrous cellulose-containing dispersion containing the target fine fibrous cellulose with ion-exchanged water so that the content was 0.2% by mass. The fine fibrous cellulose-containing slurry was treated with an ion-exchange resin and then titrated with an alkali for measurement.
The ion-exchange resin treatment was carried out by adding 1/10 by volume of a strongly acidic ion-exchange resin (Amberjet 1024; conditioned by Organo Co., Ltd.) to the fine fibrous cellulose-containing slurry and shaking for 1 hour. After that, the slurry was separated from the resin by pouring it onto a mesh with an opening of 90 μm.
In addition, titration with an alkali is carried out by adding 10 μL of 0.1N sodium hydroxide aqueous solution every 5 seconds to the fine fibrous cellulose-containing slurry after treatment with an ion exchange resin, while measuring the change in the pH value indicated by the slurry. It was carried out by measuring. The titration was performed while nitrogen gas was blown into the slurry from 15 minutes before the start of the titration. In this neutralization titration, two points where the increment (the differential value of the pH with respect to the amount of alkali added) are maximized are observed in the curve obtained by plotting the measured pH against the amount of alkali added. Among these, the maximum point of the increment obtained first when the alkali is first added is called the first end point, and the maximum point of the increment obtained next is called the second end point (Fig. 4). The amount of alkali required from the start of titration to the first end point is equal to the amount of first dissociated acid in the slurry used for titration. Also, the amount of alkali required from the start of titration to the second end point is equal to the total amount of dissociated acid in the slurry used for titration. The amount of alkali (mmol) required from the start of titration to the first end point is divided by the solid content (g) in the slurry to be titrated, and the amount of phosphorous acid groups (first dissociated acid amount) (mmol/g ). Further, the value obtained by dividing the amount of alkali (mmol) required from the start of titration to the second end point by the solid content (g) in the slurry to be titrated was defined as the total amount of dissociated acid (mmol/g).

<Measurement of fiber width>
The fiber width of fine fibrous cellulose was measured by the following method. The supernatant of the fine fibrous cellulose dispersion was diluted with water to a concentration of 0.01% by mass or more and 0.1% by mass or less, and the diluted solution was added dropwise to the hydrophilized carbon grid film. After drying, it was stained with uranyl acetate and observed with a transmission electron microscope (JEOL-2000EX, manufactured by JEOL Ltd.). As a result, it was confirmed that the fine fibrous cellulose was formed with a width of about 4 nm.

<Sheeting>
Polyethylene glycol (manufactured by Fuji Film Wako Pure Chemical Industries, Ltd., molecular weight: 4,000,000) was added to the fine fibrous cellulose dispersion in an amount of 20 parts by mass with respect to 100 parts by mass of fine fibrous cellulose. After that, the concentration was adjusted so that the solid content concentration was 0.6% by mass. The dispersion was weighed so that the finished basis weight of the sheet was 75 g/m ² , coated on a commercially available acrylic plate, and dried in a drier at 70° C. for 24 hours. A blocking plate was arranged on the acrylic plate so as to obtain a predetermined basis weight. A sheet was obtained by the above procedure, and the thickness thereof was 50 μm.

<Formation of resin layer>
A solution obtained by diluting a polycarbonate resin (Iupizeta FPC2136, manufactured by Mitsubishi Gas Chemical Co., Ltd.) with toluene (solid concentration: 10% by mass) was applied onto the sheet obtained above with a #24 wire bar and dried at 100°C. A laminated sheet (pattern forming substrate) was obtained by drying for 60 minutes with a machine. The thickness of the resin layer at this time was 5 μm.

<Sheet Haze>
The haze was measured according to JIS K 7136 using a haze meter (HM-150, manufactured by Murakami Color Research Laboratory). The haze of the laminated sheet (pattern forming substrate) after the resin layer coating was 1.0%.

<Total Light Transmittance of Sheet>
The total light transmittance was measured using a haze meter (HM-150, manufactured by Murakami Color Research Laboratory Co., Ltd.) in accordance with JIS K 7361. The total light transmittance of the laminated sheet (pattern forming substrate) after the resin layer coating was 91%.

<Linear thermal expansion coefficient of sheet>
The laminated sheet (pattern forming base material) after the resin layer coating was cut into a size of 4 mm in width×30 mm in length by a laser cutter. This was set in a thermomechanical analyzer (manufactured by Hitachi High-Tech Co., Ltd., TMA7100), and in a tensile mode, the chuck distance was 20 mm, the load was 10 g, and the temperature was raised from room temperature to 180 ° C. at a rate of 5 ° C./min under a nitrogen atmosphere. The coefficient of linear thermal expansion (ppm/K) was determined from the measured values from 100°C to 150°C when the temperature was lowered to 25°C at a rate of 5°C/min. The linear thermal expansion coefficient of the laminated sheet (pattern forming substrate) after the resin layer coating was 10 ppm/K.

(Formation of conductive pattern on substrate for pattern formation)
As an exposure apparatus, a vacuum ultraviolet (VUV) light source apparatus (SUS740 manufactured by Ushio Inc., wavelength 150 to 200 nm) was used. First, the pattern-forming substrate obtained above (circular shape with a diameter of 85 mm) was placed on a work stage in a processing chamber of an exposure apparatus. Next, a photomask (manufactured by Mitani Micronics Co., Ltd., 5 inch size, synthetic quartz, L/S = 10/10, 15/15, 20/20, 30) was placed on the pattern forming substrate placed in the processing chamber. /30, 40/40, 50/50 μm). At this time, a shim tape (manufactured by Misumi Co., Ltd., thickness 20 μm, made of SUS) was used so that the gap between the pattern forming substrate and the photomask was 20 μm. After that, the inside of the lamp housing and the space above the photomask in the processing chamber were filled with nitrogen gas through a gas inlet provided inside the lamp housing of the exposure apparatus. At this time, the space above the photomask in the processing chamber was filled with nitrogen gas through a passage hole that spatially connects the lamp housing and the space above the photomask in the processing chamber. The space above the photomask in the processing chamber and the work processing space below the photomask are airtightly divided, and nitrogen gas does not flow into the work processing space, and the atmosphere contains oxygen.

Then, it was exposed for 5 minutes using an exposure device. At this time, the VUV emitted by the VUV short arc flash lamp (VUV-SFL) in the lamp housing of the exposure apparatus passed through the parabolic mirror and was irradiated onto the work stage as parallel light. After 5 minutes of VUV irradiation, the water contact angle was 27° when pure water was dropped on the exposed portion of the surface of the pattern forming substrate. The water contact angle of the surface of the pattern forming substrate before exposure was 87°.

The exposed pattern-forming substrate was removed from the exposure device, and placed on a horizontal table. Next, a conductive ink (FlowMetal SW1000 series, manufactured by Bando Kagaku Co., Ltd.) is applied to the pattern forming base material with a coating thickness of 12.5 μm using a baker applicator (YBA type, manufactured by Yoshimitsu Seiki Co., Ltd.), and a hot plate is used. above, and dried at 120° C. for 30 minutes.

(evaluation)
The portion of the pattern forming base material irradiated with VUV was observed with an optical microscope and evaluated. As a result, portions where the conductive ink was applied were confirmed on the surface of the resin layer of the pattern forming substrate. The L/S patterns of 10/10, 20/20, 30/30, 40/40 and 50/50 μm were formed separately.

1 flash lamp (VUV-SFL)
2 Parabolic mirror 3 Lamp housing 3a First gas inlet 3b First exhaust port 3c Passing hole 4 Permeable window 5 Processing chamber 5a Second exhaust port 5b Second gas inlet 5c Third gas Exhaust port 6 Photomask 7 Work stage 11 Power supply means 12 Trigger circuit unit 13 Power supply unit 14 Charger 20 Pattern forming substrate 22 Base layer 24 Resin layer 50 Pattern structure containing sheet 52 Vacuum ultraviolet irradiation unit 54 Conductive unit 100 Vacuum ultraviolet irradiation Processing device A Upper space B Work processing space

Claims (5)

A step of placing a pattern forming photomask on top of a pattern forming base material having a base layer containing fibrous cellulose with a fiber width of 100 nm or less and a resin layer, and irradiating vacuum ultraviolet rays;
A step of applying a conductive material to the vacuum ultraviolet irradiation part on the pattern forming substrate to form a pattern ,
The fibrous cellulose contains an ionic substituent,
The base layer containing fibrous cellulose further contains a hydrophilic polymer,
The method for producing a pattern structure containing sheet, wherein in the step of irradiating with vacuum ultraviolet rays, oxygen is present between the photomask and the pattern forming substrate . 2. The method for producing a pattern structure-containing sheet according to claim 1, wherein, in the step of forming the pattern, a pattern having a thinnest line of 1 [mu]m or more and 1 mm or less is formed. 3. The method for manufacturing a pattern structure-containing sheet according to claim 1, wherein the step of irradiating the vacuum ultraviolet rays is a step of irradiating the vacuum ultraviolet rays as parallel light. The method for producing a pattern structure-containing sheet according to any one of claims 1 to 3 , wherein the fibrous cellulose contains a phosphorous acid group or a substituent derived from a phosphorous acid group. The method for producing a pattern structure containing sheet according to any one of claims 1 to 4 , wherein the haze of the pattern forming substrate is 10% or less.

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