JP2020185680A - Pattern formation substrate - Google Patents

Abstract

To provide a pattern formation substrate with good patterning properties.SOLUTION: There is provided a pattern formation substrate that comprises: a base layer containing fibrous cellulose with a fiber width of 1000 nm or less; and a resin layer, in which a content of a low molecular weight compound having a molecular weight of 400 or less in the base layer is 20 mass% or less based on the total mass% of the base layer.SELECTED DRAWING: Figure 1

Description

The present invention relates to a base material for pattern formation. Specifically, the present invention relates to a pattern-forming substrate containing fine fibrous cellulose.

In recent years, due to the substitution of petroleum resources and increasing environmental awareness, materials using reproducible natural fibers have been attracting attention. Among natural fibers, fibrous cellulose having a fiber diameter of 10 μm or more and 50 μm or less, particularly fibrous cellulose (pulp) derived from wood, has been widely used mainly as paper products.

As the fibrous cellulose, fine fibrous cellulose having a fiber diameter of 1 μm or less is also known. Further, a sheet composed of such fine fibrous cellulose and a composite containing a fine fibrous cellulose-containing sheet and a resin layer have been developed. It is known that in sheets and composites containing fine fibrous cellulose, the contact points between fibers are remarkably increased, so that the tensile strength and the like are greatly improved. It is also known that the transparency is greatly improved when the fiber width is shorter than the wavelength of visible light.

It is also being considered to use such a sheet containing fine fibrous cellulose for a wiring board or a circuit board. 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 for a wiring board or a circuit board. .. Further, Patent Document 5 discloses a cellulose fiber composite film containing a cellulose fiber and a low molecular weight lubricant, and it is considered to use such a composite film as a wiring substrate.

Japanese Unexamined Patent Publication No. 2005-060680 Japanese Unexamined Patent Publication No. 2016-089022 JP-A-2018-132655 JP-A-2018-170518 JP-A-2017-0781151

When a composite sheet containing fine fibrous cellulose as described above is used as a base material for pattern formation, it is required to be a substrate capable of forming a pattern with high accuracy. That is, there is a demand for the development of a composite sheet containing fine fibrous cellulose and having good patterning properties.

Therefore, in order to solve the problems of the prior art, the present inventors have proceeded with studies for the purpose of providing a composite sheet (base material for pattern formation) having excellent patterning property.

As a result of diligent studies to solve the above problems, the present inventors have achieved a composite sheet having excellent patterning property by laminating a resin layer on a base layer containing fibrous cellulose having a fiber width of 1000 nm or less. It was found that (a substrate for pattern formation) can be obtained.
Specifically, the present invention has the following configuration.

[1] A base material for pattern formation containing a base layer containing fibrous cellulose having a fiber width of 1000 nm or less and a resin layer.
A base material for pattern formation in which the content of a low molecular weight compound having a molecular weight of 400 or less in the base layer is less than 20% by mass with respect to the total mass of the base layer.
[2] The base material for pattern formation according to [1], which has a density of 1.00 g / cm ³ or more.
[3] The base material for pattern formation according to [1] or [2], which has a tensile elastic modulus of 2.0 GPa or more.
[4] The base material for pattern formation according to any one of [1] to [3], wherein the haze is 10.0% or less.
[5] The pattern-forming substrate according to any one of [1] to [4], wherein the pattern-forming substrate has a shrinkage rate of 1.2% or less after being held in a nitrogen atmosphere at a temperature of 110 ° C. for 1 hour. Base material.
[6] The base material for pattern formation according to any one of [1] to [5], wherein the arithmetic average roughness of the surface of the resin layer is 100 nm or less.
[7] The base material for pattern formation according to any one of [1] to [6], wherein the water contact angle on the surface of the resin layer is 60 ° or more.
[8] The pattern-forming substrate according to any one of [1] to [7], wherein the content of the fibrous cellulose is 10% by mass or more with respect to the total mass of the pattern-forming substrate.
[9] The pattern-forming base material according to any one of [1] to [8], wherein the fibrous cellulose has a phosphoric acid or a substituent derived from the phosphoric acid.
[10] The pattern-forming base material according to any one of [1] to [9], wherein the resin layer contains a hydrophobic resin.
[11] The pattern-forming base material according to any one of [1] to [10], wherein the base layer further contains a hydrophilic polymer.

According to the present invention, a composite sheet (base material for pattern formation) having excellent patterning properties can be obtained.

FIG. 1 is a cross-sectional view illustrating the configuration of the pattern forming base material of the present invention. FIG. 2 is a graph showing the relationship between the amount of NaOH added dropwise and the pH of a fibrous cellulose-containing slurry having a phosphorus oxo acid group. FIG. 3 is a graph showing the relationship between the amount of NaOH added dropwise to the fibrous cellulose-containing slurry having a carboxy group and the pH.

Hereinafter, the present invention will be described in detail. The description of the constituent elements described below may be based on typical embodiments or specific examples, but the present invention is not limited to such embodiments.

(Base material for pattern formation)
The present invention is a pattern-forming base material containing a base layer containing fibrous cellulose having a fiber width of 1000 nm or less and a resin layer, and the content of a low molecular weight compound having a molecular weight of 400 or less in the base layer is the entire base layer. It relates to a pattern-forming substrate which is less than 20% by mass with respect to the mass. In the present specification, fibrous cellulose having a fiber width of 1000 nm or less may be referred to as fine fibrous cellulose or CNF.

FIG. 1 is a cross-sectional view illustrating the configuration of the pattern forming base material of the present invention. As shown in FIG. 1, the pattern-forming base material 10 of the present invention has a base layer 2 containing fine fibrous cellulose and a resin layer 6. The base layer 2 and the resin layer 6 are laminated so as to be in contact with each other on one of the surfaces. The pattern-forming base material may have at least one base layer 2 and one resin layer 6, but may have two or more base layers 2 and two or more resin layers 6. It may be. For example, the structure may have a resin layer 6 on both sides of the base layer 2.

Since the pattern-forming base material of the present invention has the above-mentioned structure, it is excellent in patterning property. Specifically, the patterning property of the base material for pattern formation under a normal temperature and pressure environment is good. For example, when the pattern-forming substrate is allowed to stand in a normal temperature and humidity environment for 24 hours and then a pattern is formed using a photomask, the patterning property is good.

The patterning forming surface is a surface on the resin layer side of the pattern forming base material. That is, in the pattern-forming base material of the present invention, a pattern is formed on the exposed surface of the resin layer. The patterning property can be evaluated by depositing a metal such as gold on the pattern formed on the resin layer and measuring the vapor deposition pattern (for example, line and / or space width).

The pattern-forming substrate of the present invention has a base layer containing fibrous cellulose having a fiber width of 1000 nm or less. The content of the fine fibrous cellulose is preferably 10% by mass or more, more preferably 50% by mass or more, and further preferably 60% by mass or more, based on the total mass of the pattern-forming base material. It is preferably 70% by mass or more, and more preferably 70% by mass or more.

The overall thickness of the pattern-forming substrate of the present invention 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. The overall thickness of the pattern-forming substrate is preferably 1 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 base material for pattern formation is appropriately adjusted according to the shape of the pattern to be formed and its use.

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. The thickness of the base layer is preferably 995 μm or less, more preferably 695 μm or less, and further preferably 495 μm or less. Here, the thickness of the base layer constituting the pattern-forming base material is determined by cutting out a cross section of the pattern-forming base material with an ultramicrotome UC-7 (manufactured by JEOL Ltd.) and observing the cross section with an electron microscope, a magnifying glass or visually. Then, it is a value to be measured. When the pattern-forming substrate contains 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 base material is preferably 0.1 μm or more, more preferably 0.5 μm or more, and further preferably 1 μm or more. 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 base material is determined by cutting out a cross section of the pattern-forming base material with an ultramicrotome UC-7 (manufactured by JEOL Ltd.) and visually examining the cross section with an electron microscope, a magnifying glass or a visual microscope. It is a value that is observed and measured. When the pattern-forming base material contains a plurality of resin layers, 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 1.20 g / cm ³ or more, still more preferably 1.30 g / cm ³ or more, It is particularly preferably 1.40 g / cm ³ or more. The density of the pattern-forming base material was calculated by dividing the basis weight of the pattern-forming base material by the thickness. The thickness of the base material for pattern formation can be measured with a stylus type thickness gauge (Millitron 1202D manufactured by Marl Co., Ltd.).

The total light transmittance of the pattern-forming substrate is preferably 60% or more, more preferably 70% or more, further preferably 80% or more, and particularly preferably 90% or more. By setting the total light transmittance of the pattern-forming base material within the above range, the compatibility of the pattern-forming base material is enhanced in the case of performing optical positioning in the patterning process. Here, the total light transmittance is a value measured using a haze meter (manufactured by Murakami Color Technology Research Institute, HM-150) in accordance with JIS K 7361.

The haze of the base material for pattern formation is preferably 10.0% or less, more preferably 5.0% or less, further preferably 2.5% or less, further preferably 2.0% or less, and 1.5% or less. Even more preferably, 1.0% or less is particularly preferable. By setting the haze of the pattern-forming base material within the above range, the compatibility of the pattern-forming base material is enhanced when optical positioning is performed in the patterning process. Here, the haze is a value measured using a haze meter (HM-150, manufactured by Murakami Color Technology Research Institute) in accordance with JIS K 7136.

The tensile elastic modulus of the pattern-forming substrate at 23 ° C. and 50% relative humidity is preferably 2.0 GPa or more, more preferably 2.5 GPa or more, and even more preferably 3.0 GPa or more. , 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 elastic modulus of the pattern-forming base material at 23 ° C. and 50% relative humidity is preferably 30 GPa or less. The tensile elastic modulus of the pattern-forming substrate is a value measured in accordance with JIS P 8113, and the tensile elastic modulus is a value calculated from the maximum positive inclination value in the SS curve (stress-strain curve). Is.

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

The coefficient of linear thermal expansion of the pattern-forming substrate is preferably 50 ppm / K or less.
It is more preferably 40 ppm / K or less, and further preferably 30 ppm / K or less. The coefficient of linear thermal expansion of the pattern-forming base material is 4 mm wide x 30 mm long, after the pattern-forming base material is set in a thermomechanical analyzer (TMA7100, manufactured by Hitachi High-Tech), the chuck distance is 20 mm and the load is 10 g in the pull mode. It is a value calculated from the measured values of 100 ° C. to 150 ° C. when the temperature is raised from room temperature to 180 ° C. at 5 ° C./min and lowered from 180 ° C. to 25 ° C. at 5 ° C./min under a nitrogen atmosphere.

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

The water contact angle on 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 base material is the water contact angle on the surface of the resin layer of the pattern-forming base material. The water contact angle on the surface of the pattern-forming base material is the water contact angle 30 seconds after dropping 4 μL of distilled water onto the surface of the pattern-forming base material. A dynamic water contact angle tester is used for the measurement. As the dynamic water contact angle tester, for example, 1100 DAT manufactured by Fibro can be used.

(Resin layer)
The resin layer is a layer containing a natural resin or a synthetic resin as a main component. Here, the main component refers to a component 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, based on the total mass of the resin layer. The above is particularly preferable. The resin content may be 100% by mass or 95% by mass or less.

Examples of the natural resin include rosin-based resins such as rosin, rosin ester, and hydrogenated rosin ester.

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 the polycarbonate resin, the urethane resin and the acrylic resin, and more preferably at least one selected from the urethane resin and the acrylic resin. 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-based resins and aliphatic polycarbonate-based resins. These specific polycarbonate-based resins are known, and examples thereof include the polycarbonate-based resins described in JP-A-2010-023275.

The resin layer preferably contains a hydrophobic resin. In addition, 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 it is in an emulsion state.

In the pattern-forming base material, the resin layer may contain an adhesion aid. Examples of the adhesion aid include a compound containing at least one selected from an isocyanate group, a carbodiimide group, an epoxy group, an oxazoline group, an amino group and a silanol group, and an organosilicon compound. Among them, the adhesion aid is preferably at least one selected from a compound containing an isocyanate group (isocyanate compound) and an organosilicon compound. Examples of the organosilicon compound include a silane coupling agent condensate and a silane coupling agent.

Examples of the isocyanate compound include polyfunctional isocyanates which are polyisocyanate compounds or more. Specific examples of the polyisocyanate compound include aromatic polyisocyanates having 6 to 20 carbon atoms excluding carbon in the NCO group, aliphatic polyisocyanates having 2 to 18 carbon atoms, and 6 to 15 carbon atoms. Aliphatic polyisocyanates, aralkyl-type polyisocyanates having 8 or more and 15 or less carbon atoms, modified products of these polyisocyanates, and mixtures of two or more of these can be mentioned. Among them, an alicyclic polyisocyanate having 6 to 15 carbon atoms, that is, isocyanurate is preferably used.

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

Examples of the organosilicon compound include a compound having a siloxane structure and a compound that forms a siloxane structure by condensation. For example, a silane coupling agent or a condensate of a silane coupling agent can be mentioned. The silane coupling agent may have a functional group other than the alkoxysilyl group, or may have no other functional group. Examples of the functional group other than the alkoxysilyl group include a vinyl group, an epoxy group, a styryl group, a methacryloxy group, an acryloxy group, an amino group, a ureido group, a mercapto group, a sulfide group and an isocyanate group. The silane coupling agent used in the present invention is preferably a silane coupling agent containing a methacryloxy group.

Specific examples of the silane coupling agent having a methacryloxy group in the molecule include methacryloxypropylmethyldimethoxysilane, methacryloxypropyltrimethoxysilane, methacryloxypropylmethyldiethoxysilane, and methacryloxypropyltriethoxysilane. Examples thereof include 1,3-bis (3-methacryloxypropyl) tetramethyldisiloxane. 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 three or more alkoxysilyl groups.

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

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

Further, the adhesion aid may be unevenly distributed in the region on the base layer side of the resin layer. For example, when an organosilicon compound is used as the adhesion aid, the organosilicon compound may be unevenly distributed in the region on the base layer side of the resin layer.
Here, the state of being unevenly distributed in the region on the base layer side of the resin layer means that the two concentrations of the following regions ((d) and (e)) are measured and the difference between these concentrations is more than twice. The state of being out.
(D) Region from the surface of the resin layer on the base layer side to 10% of the total thickness of the resin layer (e) Region of ± 5% (total 10%) of the total thickness from the central surface in the thickness direction of the resin layer. The concentration of the adhesion aid is a numerical value measured by an X-ray electron spectroscope or an infrared spectrophotometer, and is a cross section of a predetermined region of the pattern forming substrate by Ultramicrotome UC-7 (manufactured by JEOL). It is a value obtained by cutting out and measuring the cross section with the device.

An organosilicon compound-containing layer may be provided on the surface of the resin layer on the base layer side, and such a state is also included in a state in which the organosilicon compounds are unevenly distributed in the region on the base layer side of the resin layer. The organosilicon compound-containing layer may be a coating layer formed by applying an organosilicon compound-containing coating liquid.
When the 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 on the base layer side of the resin layer" is "exposed of the organosilicon compound-containing layer". It shall be read as "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 part by mass or more, and more preferably 0.5 part by mass or more with respect to 100 parts by mass of the resin contained in the resin layer. The content of the adhesion aid is preferably 40 parts by mass or less, and more preferably 35 parts by mass or less, based on 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, based on 100 parts by mass of the resin contained in the resin layer. It is more preferably 18 parts by mass or more. The content of the isocyanate compound is preferably 40 parts by mass or less, more preferably 35 parts by mass or less, and more preferably 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 part by mass or more, preferably 0.5 part by mass or more, based on 100 parts by mass of the resin contained in the resin layer. More preferably. The content of the organosilicon compound is preferably 10 parts by mass or less, and more preferably 5 parts by mass or less, based on 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 enhanced more effectively.

When the adhesion aid is an isocyanate compound, the content of the isocyanate group contained in the resin layer is preferably 0.5 mmol / g or more, more preferably 0.6 mmol / g or more, and 0.8 mmol or more. It is more preferably / g or more, and particularly preferably 0.9 mmol / g or more. Further, the content of the isocyanate group 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.

The surface of the resin layer on the base layer side may be surface-treated. Examples of the surface treatment method include corona treatment, plasma discharge treatment, UV irradiation treatment, electron beam irradiation treatment, flame treatment and the like. Above all, the surface treatment is preferably at least one selected from the corona treatment and the plasma discharge treatment. The plasma discharge treatment is preferably a vacuum plasma discharge treatment.

The surface of the resin layer on the base layer side may form a fine concavo-convex structure. Since the surface of the resin layer on the base layer side has a fine concavo-convex structure, the adhesion between the base layer and the resin layer can be more effectively enhanced. When the surface of the resin layer on the base layer side has a fine concavo-convex structure, such a structure may be formed by, for example, a treatment step such as a blasting treatment, an embossing treatment, an etching treatment, a corona treatment, or a plasma discharge treatment. preferable. In addition, in this specification, a fine concavo-convex structure means a structure in which the number of recesses existing on one straight line having a length of 1 mm drawn at an arbitrary position is 10 or more. When measuring the number of recesses, the pattern-forming substrate is immersed in ion-exchanged water for 24 hours, and then the base layer is peeled off from the resin layer. After that, the surface of the resin layer on the base layer side can be measured by scanning with a stylus type surface roughness meter (Surf Corder series manufactured by Kosaka Research Institute). When the pitch of the unevenness is extremely small on the submicron and nano-order, the number of unevenness can be measured from the observation image of the scanning probe microscope (AFM5000II and AFM5100N manufactured by Hitachi High-Tech Science Co., Ltd.).

The resin layer may contain an arbitrary component other than the synthetic resin. Examples of the optional component 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) having a fiber width of 1000 nm or less. The content of the fine fibrous cellulose is preferably 10% by mass or more, more preferably 50% by mass or more, further preferably 60% by mass or more, and 70% by mass with respect to the total mass of the base layer. It is more preferably% or more.

The density of the base layer is preferably 1.0 g / cm ³ or more, more preferably 1.1 g / cm ³ or more, and further preferably 1.2 g / cm ³ or more. The density of the base layer is preferably 1.8 g / cm ³ or less, more preferably 1.7 g / cm ³ or less, and further preferably 1.6 g / cm ³ or less. When the pattern-forming substrate contains 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 from the basis weight and thickness of the base layer in accordance with JIS P 8118. The basis weight of the base layer can be calculated by cutting with Ultra Microtome UC-7 (manufactured by JEOL Ltd.) so that only the base layer of the pattern forming base material remains, and in accordance with JIS P 8124. When the base layer contains an arbitrary component other than the fine fibrous cellulose, the density of the base layer is a density containing an arbitrary component other than the fine fibrous cellulose.

The present invention is also characterized in that the base layer is a non-porous layer. Here, the fact that the base layer is non-porous means that the density of the entire base layer is 1.0 g / cm ³ or more. When 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 it is distinguished from the porous sheet or layer.
The non-porous nature of the 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).
Equation (a): Porosity (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 the solid content constituting the base layer.

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

The fiber width of the fibrous cellulose can be measured, for example, by observation with an electron microscope. The average fiber width of the fibrous cellulose is, for example, 1000 nm or less. The average fiber width of the fibrous cellulose is, for example, 2 nm or more and 1000 nm or less, more preferably 2 nm or more and 100 nm or less, further preferably 2 nm or more and 50 nm or less, and 2 nm or more and 10 nm or less. Especially preferable. By setting the average fiber width of the fibrous cellulose to 2 nm or more, it becomes easy to suppress the dissolution of the cellulose molecules in water. The fibrous cellulose is, for example, monofibrous 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 having 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 prepare a sample for TEM observation. And. If it contains wide fibers, an SEM image of the surface cast on the glass may be observed. Next, observation is performed using an electron microscope image at a magnification of 1000 times, 5000 times, 10000 times, or 50,000 times depending on the width of the fiber to be observed. However, the sample, observation conditions and magnification should be adjusted so as to satisfy the following conditions.
(1) A straight line X is drawn at an arbitrary position in the observation image, and 20 or more fibers intersect the straight line X.
(2) A straight line Y that intersects the straight line perpendicularly is drawn in the same image, and 20 or more fibers intersect the straight line Y.
The width of the fiber intersecting the straight line X and the straight line Y is visually read with respect to the observation image satisfying the above conditions. In this way, at least three sets of observation images of surface portions that do not overlap each other are obtained. Next, for each image, the width of the fiber intersecting the straight line X and the straight line Y is read. As a result, at least 20 fibers × 2 × 3 = 120 fibers are read. Then, the average value of the read fiber widths is taken as the average fiber width of the fibrous cellulose.

The fiber length of the fibrous cellulose is not particularly limited, but 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 crystal region of the fibrous cellulose can be suppressed. It is also possible to set the slurry viscosity of the fibrous cellulose in an appropriate range. The fiber length of the fibrous cellulose can be obtained by, for example, image analysis by TEM, SEM, or AFM.

The fibrous cellulose preferably has an I-type crystal structure. Here, the fact that the fibrous cellulose has an I-type crystal structure can be identified in the diffraction profile obtained from a wide-angle X-ray diffraction photograph using CuKα (λ = 1.5418 Å) monochromatic with graphite. Specifically, it can be identified by having typical peaks at two positions, 2θ = 14 ° or more and 17 ° or less and 2θ = 22 ° or more and 23 ° or less. The ratio of the type I crystal structure to the fine fibrous cellulose is, for example, preferably 30% or more, more preferably 40% or more, and further 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 crystallinity is determined by a conventional method from the X-ray diffraction profile measured and the pattern (Seagal et al., Textile Research Journal, Vol. 29, p. 786, 1959).

The axial ratio (fiber length / fiber width) of the fibrous cellulose is not particularly limited, but is preferably 20 or more and 10000 or less, and more preferably 50 or more and 1000 or less. By setting the axial ratio to the above lower limit value or more, it is easy to form a sheet containing fine fibrous cellulose. By setting the axial ratio to the above upper limit value or less, for example, when fibrous cellulose is treated as a dispersion liquid, it is preferable in that handling such as dilution becomes easy.

The fibrous cellulose in the present embodiment has, for example, both a crystalline region and a non-crystalline region. In particular, fine fibrous cellulose having both a crystalline region and a non-crystalline region and having a high axial ratio is realized by a method for producing fine fibrous cellulose 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 defibration treatment can be improved. The ionic substituent can include, for example, either one or both of an anionic group and a cationic group. In the present embodiment, it is particularly preferable to have an anionic group as the ionic substituent.

Examples of the anionic group as an ionic substituent include a phosphoric acid group or a substituent derived from a phosphoric acid group (sometimes simply referred to as a phosphoric acid group), a carboxy group or a substituent derived from a carboxy group (simply a carboxy group). It is preferably at least one selected from (sometimes referred to as), 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 phosphorus oxo acid group and a carboxy group, and particularly preferably a phosphorus oxo acid group. By introducing a phosphorus oxo acid group as an anionic group, for example, the dispersibility of fibrous cellulose can be further enhanced even under alkaline or acidic conditions, and as a result, a high-strength and highly transparent base layer can be obtained. It will be easier.

The phosphate group or the substituent derived from the phosphorus oxo acid group is, for example, a substituent represented by the following formula (1). The phosphorus oxo acid group is, for example, a divalent functional group obtained by removing a hydroxy group from phosphoric acid. Specifically, it is a group represented by −PO ₃ H ₂ . Substituents derived from a phosphorus oxo acid group include substituents such as a salt of a phosphorus oxo acid group and a phosphorus oxo acid ester group. The substituent derived from the phosphoric acid group may be contained in the fibrous cellulose as a group in which the phosphoric acid group is condensed (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 is a salt of a phosphorous acid group, a phosphorous acid ester group, or the like. May be good.

In formula (1), a, b and n are natural numbers (where a = b × m). ^{α 1, α 2, ···,} a number of alpha ⁿ and alpha 'is O ^- a and the remainder is either R, the OR. It is also possible that all of each α ⁿ and α'are O ⁻ . R is a hydrogen atom, a saturated-linear hydrocarbon group, a saturated-branched chain hydrocarbon group, a saturated-cyclic hydrocarbon group, an unsaturated-linear hydrocarbon group, and an unsaturated-branched chain hydrocarbon, respectively. A hydrogen group, an unsaturated-cyclic hydrocarbon group, an aromatic group, or an inducing group thereof. Further, n is preferably 1.

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

Further, as the inducing group in R, a functional group in which at least one of functional groups 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-mentioned various hydrocarbon groups. The group is mentioned, but is not particularly limited. The number of carbon atoms constituting the main chain of R is not particularly limited, but is preferably 20 or less, and more preferably 10 or less. By setting the number of carbon atoms constituting the main chain of R to the above range, the molecular weight of the phosphorus oxo acid group can be set to an appropriate range, the penetration into the fiber raw material is facilitated, and the yield of the fine cellulose fiber is increased. You can also do it.

β ^{b +} is a monovalent or higher cation composed of an organic substance or an inorganic substance. Examples of monovalent or higher cations composed of organic substances include aliphatic ammonium or aromatic ammonium, and examples of monovalent or higher valent cations composed of inorganic substances include ions of alkali metals such as sodium, potassium, and lithium. Examples thereof include cations of divalent metals such as calcium and magnesium, hydrogen ions, and the like, but the present invention is not particularly limited. These may be applied alone or in combination of two or more. The monovalent or higher cation composed of an organic substance or an inorganic substance is preferably sodium or potassium ion which is hard to yellow when the fiber raw material containing β is heated and is easily industrially used, but is not particularly limited. In addition, β ^{b +} may be an organic onium ion, and in this case, it is particularly preferable that it is an organic ammonium ion.

The amount of the ionic substituent introduced into the fibrous cellulose is, for example, 0.10 mmol / g or more, more preferably 0.20 mmol / g or more, and 0.50 mmol / g per 1 g (mass) of the fibrous cellulose. It is more preferably / g or more, and particularly preferably 1.00 mmol / g or more. The amount of the ionic substituent introduced into the fibrous cellulose is preferably 5.20 mmol / g or less per 1 g (mass) of the fibrous cellulose, more preferably 3.65 mmol / g or less. It is more preferably .50 mmol / g or less, and even more preferably 3.00 mmol / g or less. By setting the amount of the ionic substituent introduced within the above range, it is possible to facilitate the miniaturization of the fiber raw material and enhance the stability of the fibrous cellulose. Here, the denominator in the unit mmol / g indicates the mass of fibrous cellulose when the counter ion of the ionic substituent is a hydrogen ion (H ⁺ ).

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

FIG. 2 is a graph showing the relationship between the amount of NaOH added dropwise and the pH of a fibrous cellulose-containing slurry having a phosphoric acid group as an ionic substituent. The amount of the phosphorus oxo acid group introduced into the fibrous cellulose is measured, for example, as follows.
First, the slurry containing fibrous cellulose is treated with a strongly acidic ion exchange resin. If necessary, the defibration treatment similar to the defibration treatment step described later may be performed on the measurement target before the treatment with the strongly acidic ion exchange resin.
Next, the change in pH is observed while adding an aqueous sodium hydroxide solution, and a titration curve as shown in the upper part of FIG. 2 is obtained. The titration curve shown in the upper part of FIG. 2 plots the measured pH with respect to the amount of alkali added, and the titration curve shown in the lower part of FIG. 2 plots the pH with respect to the amount of alkali added. The increment (differential value) (1 / mmol) is plotted. In this neutralization titration, two points are confirmed in which the increment (differential value of pH with respect to the amount of alkali dropped) becomes maximum in the curve plotting the measured pH with respect to the amount of alkali added. Of these, the maximum point of the increment obtained first when alkali is 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 amount of first dissociating acid of the 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 amount of the second dissociating acid of the fibrous cellulose contained in the slurry used for the titration, and the amount of alkali required from the start to the second end point of the titration is the fibrous cellulose contained in the slurry used for the titration. Is equal to the total amount of dissociated acid. Then, the 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 oxo acid group introduced (mmol / g). The amount of phosphorus oxo acid group introduced (or the amount of phosphorus oxo acid group) simply means the amount of the first dissociated acid.
In FIG. 2, the region from the start of titration to the first end point is referred to as a first region, and the region from the first end point to the second end point is referred to as a second region. For example, when the phosphoric acid group is a phosphoric acid group and this phosphoric acid group causes condensation, the amount of weakly acidic groups (second dissociated acid amount) in the phosphoric acid group apparently decreases, and the first region The amount of alkali required for the second region is smaller than the amount of alkali required for the second region. On the other hand, the amount of strongly acidic groups (first dissociated acid amount) in the phosphorus oxo acid group is the same as the amount of phosphorus atoms regardless of the presence or absence of condensation. Further, when the phosphorous acid group is a phosphorous acid group, the weakly acidic group does not exist in the phosphorous acid group, so that the amount of alkali required for the second region is reduced or the amount of alkali required for the second region is reduced. May be zero. In this case, the titration curve has one point where the pH increment is maximized.

Since the denominator of the above-mentioned phosphorus oxo acid group introduction amount (mmol / g) indicates the mass of the acid-type fibrous cellulose, the phosphorus oxo acid group amount of the acid-type fibrous cellulose (hereinafter referred to as the phosphorus oxo acid group amount). (Called (acid type))). On the other hand, when the counterion of the phosphorus oxo acid group is replaced 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 a counterion. This makes it possible to determine the amount of phosphorus oxo acid groups (hereinafter, the amount of phosphorus oxo acid groups (C type)) possessed by the fibrous cellulose in which the cation C is a counterion.
That is, it is calculated by the following formula.
Amount of phosphorus oxo acid group (C type) = Amount of phosphorus oxo acid group (acid type) / {1+ (W-1) x A / 1000}
A [mmol / g]: Total amount of anion derived from phosphoric acid group of fibrous cellulose (total amount of dissociated acid of phosphoric acid group)
W: Formula amount per valence of cation C (for example, Na is 23, Al is 9)

FIG. 3 is a graph showing the relationship between the amount of NaOH added dropwise and pH with respect to a dispersion containing fibrous cellulose having a carboxy group as an ionic substituent. The amount of the carboxy group introduced into the fibrous cellulose is measured, for example, as follows.
First, the dispersion containing fibrous cellulose is treated with a strongly acidic ion exchange resin. If necessary, the defibration treatment similar to the defibration treatment step described later may be performed on the measurement target before the treatment with the strongly acidic ion exchange resin.
Next, the change in pH is observed while adding an aqueous sodium hydroxide solution, and a titration curve as shown in the upper part of FIG. 3 is obtained. The titration curve shown in the upper part of FIG. 3 plots the measured pH with respect to the amount of alkali added, and the titration curve shown in the lower part of FIG. 3 plots the pH with respect to the amount of alkali added. The increment (differential value) (1 / mmol) is plotted. In this neutralization titration, in the curve plotting the measured pH with respect to the amount of alkali added, one point was confirmed where the increment (differential value of pH with respect to the amount of alkali dropped) became maximum, and this maximum point was the first. Called one end point. Here, the region from the start of titration to the first end point in FIG. 3 is referred to as a first region. The amount of alkali required in the first region is equal to the amount of carboxy 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 liquid containing the fibrous cellulose to be titrated, so that the amount of carboxy group introduced (mmol). / G) is calculated.

Since the denominator of the above-mentioned carboxy group introduction amount (mmol / g) is the mass of the acid type fibrous cellulose, the carboxy group amount of the acid type fibrous cellulose (hereinafter, the carboxy group amount (acid type)). ) Is shown. On the other hand, when the counterion of the carboxy group is replaced 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 a counterion. Then, the amount of carboxy groups (hereinafter, the amount of carboxy groups (C type)) possessed by the fibrous cellulose in which the cation C is a counter ion can be determined. That is, it is calculated by the following formula.
Carboxylic acid group amount (C type) = Carboxylic acid group amount (acid type) / {1+ (W-1) x (carboxyl group amount (acid type)) / 1000}
W: Formula amount per valence of cation C (for example, Na is 23, Al is 9)

In the measurement of the amount of ionic substituents by the titration method, if the amount of one drop of sodium hydroxide aqueous solution is too large, or if the titration interval is too short, the amount of ionic substituents will be lower than it should be. It may not be obtained. As an appropriate dropping amount and titration interval, for example, it is desirable to titrate 10 to 50 μL of a 0.1 N sodium hydroxide aqueous solution every 5 to 30 seconds. Further, 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>
<Fiber raw material>
Fine fibrous cellulose is produced from a fiber raw material containing cellulose. The fiber raw material containing cellulose is not particularly limited, but pulp is preferably used because it is easily available and inexpensive. Examples of pulp include wood pulp, non-wood pulp, and deinked pulp. The wood pulp is not particularly limited, and is, for example, broadleaf kraft pulp (LBKP), coniferous kraft pulp (NBKP), sulfite pulp (SP), dissolved pulp (DP), soda pulp (AP), and unbleached kraft pulp (UKP). ) And chemical pulp such as oxygen bleached kraft pulp (OKP), semi-chemical pulp such as semi-chemical pulp (SCP) and chemiground wood pulp (CGP), crushed wood pulp (GP) and thermomechanical pulp (TMP, BCTMP), etc. Examples include mechanical pulp. The non-wood pulp is not particularly limited, and examples thereof include cotton pulp such as cotton linter and cotton lint, and non-wood pulp such as hemp, straw and bagasse. The deinking pulp is not particularly limited, and examples thereof include deinking pulp made from used paper. As the pulp of the present embodiment, one of the above types may be used alone, or two or more types may be mixed and used. Among the above pulps, for example, wood pulp and deinked pulp are preferable from the viewpoint of availability. Further, among wood pulps, from the viewpoint of high cellulose ratio and high yield of fine fibrous cellulose during defibration treatment, long fiber fine fibrous cellulose having a small decomposition of cellulose in pulp and a large axial ratio can be obtained. From the viewpoint, for example, chemical pulp is more preferable, and kraft pulp and sulfite pulp are further preferable. When long fiber fine fibrous cellulose having a large axial ratio is used, the viscosity tends to increase.

As the fiber raw material containing cellulose, for example, cellulose contained in ascidians and bacterial cellulose produced by acetobacter can be used. Further, instead of the fiber raw material containing cellulose, a fiber formed by a linear nitrogen-containing polysaccharide polymer such as chitin or chitosan can also be used.

<Linoxo acid group introduction process>
The process for producing fine fibrous cellulose preferably includes an ionic substituent introduction step, and examples of the ionic substituent introduction step include a phosphorus oxo acid group introduction step. In the phosphorus oxo acid group introduction step, at least one compound (hereinafter, also referred to as “compound A”) selected from compounds capable of introducing a phosphorus oxo acid group by reacting with a hydroxyl group of a fiber raw material containing cellulose is introduced into cellulose. It is a step of acting on a fiber raw material containing. By this step, a phosphorus oxo acid group-introduced fiber can be obtained.

In the phosphorus oxo acid group introduction step according to the present embodiment, the reaction between the fiber raw material containing cellulose and Compound A is carried out in the presence of at least one selected from urea and its derivatives (hereinafter, also referred to as “Compound B”). You may. On the other hand, the reaction of the fiber raw material containing cellulose with the compound A may be carried out in the absence of the compound B.

As an example of the method of allowing the compound A to act on the fiber raw material in the coexistence with the compound B, 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 can be mentioned. Of these, since the reaction uniformity is high, 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. The form of the fiber raw material is not particularly limited, but is preferably cotton-like or thin sheet-like, for example. Examples of the compound A and the compound B include a method of adding the compound A and the compound B to the fiber raw material in the form of a powder or a solution dissolved in a solvent, or in a state of being heated to a melting point or higher and melted. Of these, since the reaction is highly homogeneous, it is preferable to add the mixture in the form of a solution dissolved in a solvent, particularly in the form of an aqueous solution. Further, the compound A and the compound B may be added to the fiber raw material at the same time, 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 dropped into the water. Further, the required amounts of Compound A and Compound B may be added to the fiber raw material, or after the excess amounts of Compound A and Compound B are added to the fiber raw material, respectively, the excess Compound A and Compound B are added by pressing or filtering. It may be removed.

The compound A used in this embodiment may be a compound having a phosphorus atom and capable of forming an ester bond with cellulose, and may be phosphoric acid or a salt thereof, phosphoric acid or a salt thereof, dehydration-condensed phosphoric acid or a salt thereof. Examples thereof include salts and anhydrous phosphoric acid (diphosphorus pentoxide), but the present invention is not particularly limited. As the phosphoric acid, those having various puritys can be used, and for example, 100% phosphoric acid (normal phosphoric acid) or 85% phosphoric acid can be used. Examples of phosphorous acid include 99% phosphorous acid (phosphonic acid). The dehydration-condensed phosphoric acid is one in which two or more molecules of phosphoric acid are condensed by a dehydration reaction, and examples thereof include pyrophosphoric acid and polyphosphoric acid. Phosphates, phosphorous acids, dehydration-condensed phosphates include phosphoric acid, phosphorous acid or dehydration-condensed phosphoric acid lithium salts, sodium salts, potassium salts, ammonium salts, etc. It can be a sum. Of these, from the viewpoints of high introduction efficiency of phosphoric acid group, easy improvement of defibration efficiency in the defibration step described later, low cost, and easy industrial application, sodium phosphate and sodium phosphate Salt, potassium salt of phosphoric acid, ammonium or phosphite of phosphoric acid, sodium salt of phosphite, potassium salt of phosphite, ammonium salt of phosphite are preferred, phosphoric acid, sodium dihydrogen phosphate, Disodium hydrogen phosphate, ammonium dihydrogen phosphate, or phosphoric acid and sodium phosphite are more preferred.

The amount of compound A added to the fiber raw material is not particularly limited, but for example, when the amount of compound A added is converted to the phosphorus atomic weight, the amount of phosphorus atom 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 further 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 addition amount of the phosphorus atom to the fiber raw material to be equal to or less than the above upper limit value, the effect of improving the yield and the cost can be balanced.

Compound B used in this embodiment is at least one selected from urea and its derivatives as described above. Examples of compound B include urea, biuret, 1-phenylurea, 1-benzylurea, 1-methylurea, 1-ethylurea and the like.
From the viewpoint of improving the uniformity of the reaction, compound B is preferably used as an aqueous solution. Further, 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, and more preferably 10% by mass or more and 400% by mass or less. It is more preferably 100% by mass or more and 350% by mass or less.

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

In the phosphorus oxo acid group introduction step, it is preferable to add or mix the compound A or the like to the fiber raw material and then heat-treat the fiber raw material. As the heat treatment temperature, it is preferable to select a temperature at which a phosphorus oxo acid group can be efficiently introduced while suppressing the 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 further preferably 130 ° C. or higher and 200 ° C. or lower. In addition, equipment having various heat media can be used for the heat treatment, for example, a stirring drying device, a rotary drying device, a disk drying device, a roll type heating device, a plate type heating device, a fluidized layer drying device, and a band. A mold drying device, a filtration drying device, a vibration flow drying device, an air flow 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, a method of adding compound A to a thin sheet-shaped fiber raw material by a method such as impregnation and then heating, or a method of heating while kneading or stirring the fiber raw material and compound A with a kneader or the like. Can be adopted. This makes it possible to suppress uneven concentration of the compound A in the fiber raw material and more uniformly introduce the phosphorus oxo acid group onto the surface of the cellulose fiber contained in the fiber raw material. This is because when the water molecules move to the surface of the fiber raw material due to drying, the dissolved compound A is attracted to the water molecules by the surface tension and also moves to the surface of the fiber raw material (that is, the concentration unevenness of the compound A is caused. It is considered that this is due to the fact that it can be suppressed.

Further, the heating device used for the heat treatment always keeps the water content retained by the slurry and the water content generated by the dehydration condensation (phosphate esterification) reaction between the compound A and the hydroxyl group contained in the cellulose or the like in the fiber raw material. It is preferable that the device can be discharged to the outside of the device system. Examples of such a heating device include a ventilation type oven and the like. By constantly discharging the water in the apparatus system, it is possible to suppress the hydrolysis reaction of the phosphate ester bond, which is the reverse reaction of the phosphate esterification, and also to suppress the acid hydrolysis of the sugar chain in the fiber. it can. Therefore, it is possible to obtain fine fibrous cellulose having a high axial ratio.

The heat treatment time is 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 the water is substantially removed from the fiber raw material. Is more preferable. In the present embodiment, the amount of the phosphorus oxo acid group introduced can be within a preferable range by setting the heating temperature and the heating time within an appropriate range.

The phosphorus oxo acid group introduction step may be performed at least once, but may be repeated twice or more. By performing the phosphorus oxo acid group introduction step two or more times, many phosphorus oxo acid groups can be introduced into the fiber raw material. In the present embodiment, as an example of a preferable embodiment, there is a case where the phosphorus oxo acid group introduction step is performed twice.

The amount of the phosphorus oxo acid group introduced into the fiber raw material is, for example, 0.10 mmol / g or more, more preferably 0.20 mmol / g or more, and 0.50 mmol / g / g per 1 g (mass) of fine fibrous cellulose. It is more preferably g or more, and particularly preferably 1.00 mmol / g or more. Further, the amount of the phosphorus oxo acid group introduced into the fiber raw material is preferably 5.20 mmol / g or less, more preferably 3.65 mmol / g or less per 1 g (mass) of fine fibrous cellulose, for example. It is more preferably 00 mmol / g or less. By setting the amount of the phosphorus oxo acid group introduced within the above range, it is possible to facilitate the miniaturization of the fiber raw material and enhance the stability of the fine fibrous cellulose.

<Carboxylic acid group introduction process>
The process for producing fine fibrous cellulose may include, for example, a carboxy group introduction step as an ionic substituent introduction step. The carboxy group introduction step has an oxidation treatment such as ozone oxidation, oxidation by the Fenton method, TEMPO oxidation treatment, a compound having a group derived from carboxylic acid or a derivative thereof, or a group derived from carboxylic acid with respect to the fiber raw material containing cellulose. This is done by treating with an acid anhydride of the compound or a derivative thereof.

The compound having a group derived from a carboxylic acid is not particularly limited, but for example, a dicarboxylic acid compound such as maleic acid, succinic acid, phthalic acid, fumaric acid, glutaric acid, adipic acid, itaconic acid, citric acid, aconitic acid and the like. Examples include tricarboxylic acid compounds. The derivative of the compound having a group derived from a carboxylic acid is not particularly limited, and examples thereof include an imide of an acid anhydride of a compound having a carboxy group and a derivative of an acid anhydride of a compound having a carboxy group. The imide of the acid anhydride of the compound having a carboxy group is not particularly limited, and examples thereof include an imide of a dicarboxylic acid compound such as maleimide, succinateimide, and phthalateimide.

The acid anhydride of the compound having a group derived from carboxylic acid is not particularly limited, but for example, a dicarboxylic acid compound such as maleic anhydride, succinic anhydride, phthalic anhydride, glutaric anhydride, adipic anhydride, itaconic anhydride and the like. Acid anhydride can be mentioned. The derivative of the acid anhydride of the compound having a group derived from carboxylic acid is not particularly limited, but for example, a compound having a carboxy group such as dimethylmaleic acid anhydride, diethylmaleic acid anhydride, diphenylmaleic acid anhydride and the like. Examples thereof include those in which at least a part of hydrogen atoms of the acid anhydride is substituted with a substituent such as an alkyl group or a phenyl group.

When the TEMPO oxidation treatment is carried out in the carboxy group introduction step, it is preferable to carry out the treatment under conditions of pH 6 or more and 8 or less, for example. Such a treatment is also referred to as a 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-tetramethylpiperidin-1-oxyl) as a catalyst. This can be done by adding a nitroxy radical and sodium hypochlorite as a sacrificial reagent. Further, by coexisting sodium chlorite, the aldehyde generated in the oxidation process can be efficiently oxidized to the carboxy group. Further, the TEMPO oxidation treatment may be carried out under the condition that the pH is 10 or more and 11 or less. Such a treatment is also referred to as an alkaline TEMPO oxidation treatment. The alkaline TEMPO oxidation treatment can be carried out, for example, by adding a nitroxy radical such as TEMPO as a catalyst, sodium bromide as a co-catalyst, and sodium hypochlorite as an oxidizing agent to pulp as a fiber raw material. ..

The amount of carboxy group introduced into the fiber raw material varies depending on the type of substituent, but for example, when introducing a carboxy group by TEMPO oxidation, it is preferably 0.10 mmol / g or more per 1 g (mass) of fine fibrous cellulose. , 0.20 mmol / g or more, more preferably 0.50 mmol / g or more, and particularly preferably 0.90 mmol / g or more. Further, it is preferably 2.5 mmol / g or less, more preferably 2.20 mmol / g or less, and further 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 in the present embodiment, a washing step can be performed on the ionic substituent-introduced fiber, if necessary. The washing step is carried out by washing the ionic substituent-introduced fiber with, for example, water or an organic solvent. Further, the cleaning step may be performed after each step described later, and the number of cleanings performed in each cleaning step is not particularly limited.

<Alkaline treatment process>
In the case of producing fine fibrous cellulose, an alkali treatment may be performed on the fiber raw material between the step of introducing an ionic substituent and the step of defibration treatment described later. The alkaline treatment method is not particularly limited, and examples thereof include a method of immersing the ionic substituent-introduced fiber in an alkaline 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, for example, sodium hydroxide or potassium hydroxide is preferably used as the alkaline compound because of its high versatility. Further, 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 a polar solvent containing water or a polar organic solvent exemplified by alcohol, and more preferably an aqueous solvent containing at least water. As the alkaline solution, for example, an aqueous solution of sodium hydroxide or an aqueous solution of potassium hydroxide is preferable because of its high versatility.

The temperature of the alkaline solution in the alkaline treatment step is not particularly limited, but is preferably 5 ° C. or higher and 80 ° C. or lower, and more preferably 10 ° C. or higher and 60 ° C. or lower. The immersion time of the ionic substituent-introduced fiber in the alkaline solution in the alkali treatment step is not particularly limited, but is preferably 5 minutes or more and 30 minutes or less, and 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 is preferably 100% by mass or more and 100,000% by mass or less, and 1000% by mass or more and 10000% by mass or less, based on the absolute dry mass of the ionic substituent-introduced fiber. The following is more preferable.

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

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

The method of the acid treatment is not particularly limited, and examples thereof include a method of immersing the fiber raw material in an acidic liquid containing an acid. The concentration of the acidic liquid used is not particularly limited, but is preferably 10% by mass or less, and more preferably 5% by mass or less, for example. The pH of the acidic solution used is not particularly limited, but is preferably 0 or more and 4 or less, and more preferably 1 or more and 3 or less. As the acid contained in the acidic solution, for example, an inorganic acid, a sulfonic acid, a carboxylic acid or the like can be used. Examples of the inorganic acid include sulfuric acid, nitric acid, hydrochloric acid, hydrobromic acid, hydroiodic acid, hypochlorous acid, chloric acid, chloric acid, perchloric acid, phosphoric acid, boric acid and the like. Examples of the sulfonic acid include methanesulfonic acid, ethanesulfonic acid, benzenesulfonic acid, p-toluenesulfonic acid, trifluoromethanesulfonic acid and the like. Examples of the carboxylic acid include formic acid, acetic acid, citric acid, gluconic acid, lactic acid, oxalic acid, tartaric acid and the like. 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, but is preferably 5 ° C. or higher and 100 ° C. or lower, and more preferably 20 ° C. or higher and 90 ° C. or lower. 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, and 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, but is preferably 100% by mass or more and 100,000% by mass or less, and 1,000% by mass or more and 10,000% by mass or less, for example, with respect to the absolute dry mass of the fiber raw material. Is more preferable.

<Fiber processing>
Fine fibrous cellulose can be obtained by defibrating the ionic substituent-introduced fiber in the defibration treatment step. In the defibration treatment step, for example, a defibration treatment apparatus can be used. The defibrating apparatus is not particularly limited, but for example, a high-speed defibrator, a grinder (stone mill type crusher), a high-pressure homogenizer or an ultra-high pressure homogenizer, a high-pressure collision type crusher, a ball mill, a bead mill, a disc type refiner, a conical refiner, and a twin shaft. A kneader, a vibration mill, a homomixer under high speed rotation, an ultrasonic disperser, or a beater can be used. Among the above-mentioned defibration processing devices, it is more preferable to use a high-speed defibrator, a high-pressure homogenizer, and an ultra-high-pressure homogenizer, which are less affected by crushed media and less likely to cause contamination.

In the defibration treatment step, for example, it is preferable to dilute the ionic substituent-introduced fiber with a dispersion medium to form a slurry. As the dispersion medium, one or more selected from water and an organic solvent such as a polar organic solvent can be used. The polar organic solvent is not particularly limited, but for example, 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, glycerin and the like. Examples of 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 the esters include ethyl acetate, butyl acetate and the like. Examples of the aprotic polar solvent include dimethyl sulfoxide (DMSO), dimethylformamide (DMF), dimethylacetamide (DMAc), N-methyl-2-pyrrolidinone (NMP) and the like.

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

<Arbitrary ingredient>
The base layer may contain an arbitrary component other than fine fibrous cellulose. Examples of the optional component include hydrophilic polymers and organic ions. Above all, the base layer is preferably a layer further containing a hydrophilic polymer.

The hydrophilic polymer is preferably a hydrophilic oxygen-containing organic compound (however, the above-mentioned cellulose fibers are excluded). In this case, the oxygen-containing organic compound is particularly preferably a hydrophilic organic compound. The hydrophilic oxygen-containing organic compound can improve the strength, density, chemical resistance and the like 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 one in which 1 g or more of the oxygen-containing organic compound is dissolved in 100 ml of ion-exchanged water, for example.

Examples of oxygen-containing organic compounds include polyethylene glycol, polyethylene oxide, casein, dextrin, starch, modified starch, polyvinyl alcohol, modified polyvinyl alcohol (acetoacetylated polyvinyl alcohol, etc.), polyethylene oxide, polyvinylpyrrolidone, polyvinylmethyl ether, and poly. Hydrophilic polymers such as acrylates, polyacrylamides, acrylic acid alkyl ester copolymers, urethane copolymers, cellulose derivatives (hydroxyethyl cellulose, carboxyethyl cellulose, carboxymethyl cellulose, etc.); hydrophilicity such as glycerin, sorbitol, ethylene glycol, etc. Small sex molecules can be mentioned. Among these, at least one selected from polyethylene glycol, polyethylene oxide and polyvinyl alcohol is preferable, and polyvinyl alcohol is more preferable, from the viewpoint of improving the strength, density, chemical resistance and the like of the base layer.

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. Further, the weight average molecular weight of the hydrophilic polymer is preferably 8 million or less, more preferably 5 million or less.

The content of the hydrophilic polymer is preferably 5% by mass or more, more preferably 10% by mass, further preferably 15% by mass or more, and 20% by mass, based on 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 further preferably 50% by mass or less, based on 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 high-strength and highly transparent pattern-forming base material.

Examples of the organic ion include tetraalkylammonium ion and tetraalkylphosphonium ion. Examples of the tetraalkylammonium ion include tetramethylammonium ion, tetraethylammonium ion, tetrapropylammonium ion, tetrabutylammonium ion, tetrapentylammonium ion, tetrahexylammonium ion, tetraheptylammonium ion, tributylmethylammonium ion, and lauryltrimethyl. Examples thereof include ammonium ion, cetyltrimethylammonium ion, stearyltrimethylammonium ion, octyldimethylethylammonium ion, lauryldimethylethylammonium ion, didecyldimethylammonium ion, lauryldimethylbenzylammonium ion and tributylbenzylammonium ion. Examples of the tetraalkylphosphonium ion include tetramethylphosphonium ion, tetraethylphosphonium ion, tetrapropylphosphonium ion, tetrabutylphosphonium ion, and lauryltrimethylphosphonium ion. Further, examples of the tetrapropyl onium ion and the tetrabutyl onium ion include tetra n-propyl onium ion and tetra n-butyl onium ion, respectively.

The content of the low molecular weight compound having a molecular weight of 400 or less in the base layer may be less than 20% by mass, preferably 10% by mass or less, and 5% by mass or less, based on the total mass of the base layer. Is more preferable. By setting the content of the low molecular weight compound having a molecular weight of 400 or less in the base layer within the above range, the patterning property can be improved even in the pattern forming base material after the high temperature and high humidity treatment. Here, the pattern-forming base material after the high-temperature and high-humidity treatment is a pattern-forming base material after being allowed to stand in an environment having a temperature of 60 ° C. and a relative humidity of 90% for 24 hours. For the patterning property, a metal such as gold is vapor-deposited on the pattern formed on the resin layer of the pattern-forming substrate after the high-temperature and high-humidity treatment, and the vapor deposition pattern (for example, line and / or space width) is measured. It can be evaluated by that.

(Other layers)
The pattern-forming base material may have an adhesive layer between the resin layer and the base layer. As an adhesive constituting the adhesive layer, for example, an acrylic resin can be mentioned. Examples of the adhesive other than the acrylic resin include vinyl chloride resin, (meth) acrylic acid ester resin, styrene / acrylic acid ester copolymer resin, vinyl acetate resin, and vinyl acetate / (meth) acrylic acid ester. Examples include 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.

(Manufacturing method of base material for pattern formation)
The method for producing a base material for pattern formation may include a step of forming a base layer containing fibrous cellulose having a fiber width of 1000 nm or less, and a step of applying a resin composition on the base layer. At this time, the resin composition may contain an optional component such as an adhesion aid, if necessary.
Further, the method for producing the pattern-forming base material may include a step of forming a base layer containing fibrous cellulose having a fiber width of 1000 nm or less and a step of laminating a resin film or a resin sheet on the base layer.

The steps of forming a base layer containing fibrous cellulose having a fiber width of 1000 nm or less include a step of obtaining a sheet-forming composition (hereinafter, also referred to as a slurry or a coating liquid) containing fibrous cellulose having a fiber width of 1000 nm or less. It includes a coating step of coating the sheet-forming composition on a substrate, or a paper-making step of making the sheet-forming composition. As a result, the above-mentioned sheet can be 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 can be applied onto a base material, and the sheet formed by drying the composition can be peeled off from the base material to obtain a sheet. it can. Further, by using a coating device and a long base material, sheets can be continuously produced.

The material of the base material used in the coating process is not particularly limited, but a material having high wettability to the sheet-forming composition (slurry) may suppress shrinkage of the sheet during drying, but drying It is preferable to select a sheet in which the sheet formed later can be easily peeled off. Of these, 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 of aluminum, zinc, copper, and iron plates, and their surfaces are oxidized. , Stainless film or plate, brass film or plate, etc. can be used.

In the coating process, when the viscosity of the slurry is low and it develops on the base material, a dammed frame is fixed on the base material to obtain a sheet with a predetermined thickness and basis weight. You may. The frame for damming is not particularly limited, but it is preferable to select, for example, a frame in which the end portion of the sheet that adheres after drying can be easily peeled off. From this point of view, a resin plate or a metal plate molded is more preferable. In the present embodiment, for example, a resin plate such as a polypropylene plate, an acrylic plate, a polyethylene terephthalate plate, a vinyl chloride plate, a polystyrene plate, a polycarbonate plate, a polyvinylidene chloride plate, or a metal plate such as an aluminum plate, a zinc plate, a copper plate, or an iron plate. , And those whose surfaces are oxidized, stainless steel plates, brass plates and the like can be used.
The coating machine for coating the slurry on the base material is not particularly limited, and for example, a roll coater, a gravure coater, a die coater, a curtain coater, an air doctor coater, or the like can be used. A die coater, a curtain coater, and a spray coater are particularly preferable because the thickness of the sheet can be made more uniform.

The slurry temperature and the atmospheric temperature when the slurry is applied to the substrate are not particularly limited, but are preferably, for example, 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 lower, and particularly preferably 20 ° C. or higher and 40 ° C. or lower. When the coating temperature is equal to or higher than the above lower limit, the slurry can be coated more easily. When the coating temperature is not more than the above upper limit value, volatilization of the dispersion medium during coating can be suppressed.

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

As described above, the coating step includes a step of drying the slurry coated on the substrate. The step of drying the slurry is not particularly limited, but is 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, and for example, a method of heating and drying with hot air, infrared rays, far infrared rays or near infrared rays (heat drying method) or a method of vacuum drying (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, but can be performed using, for example, an infrared device, a far infrared device, or a near infrared device.

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

<Papermaking process>
The papermaking process is performed by making a slurry with a paper machine. The paper machine used in the paper making process is not particularly limited, and examples thereof include continuous paper machines such as a long net type, a circular net type, and an inclined type, and a multi-layer paper making machine combining these. In the papermaking process, a known papermaking method such as hand-making may be adopted.

The papermaking process is performed by filtering and dehydrating the slurry with a wire to obtain a wet paper sheet, and then pressing and drying the sheet. The filter cloth used for filtering and dehydrating 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. Such a filter cloth is not particularly limited, but for example, a sheet made of an organic polymer, a woven fabric, or a porous membrane is preferable. The organic polymer is not particularly limited, but non-cellulosic organic polymers such as polyethylene terephthalate, polyethylene, polypropylene, and polytetrafluoroethylene (PTFE) are preferable. In the present embodiment, for example, a porous membrane of polytetrafluoroethylene having a pore size of 0.1 μm or more and 20 μm or less, polyethylene terephthalate having a pore size of 0.1 μm or more and 20 μm or less, a polyethylene woven fabric, or the like can be mentioned.

In the sheeting process, a method of producing a sheet from a slurry is, for example, a water-squeezed section in which a slurry containing fibrous cellulose is discharged onto the upper surface of an endless belt and a dispersion medium is squeezed from the discharged slurry to generate a web. This can be done using a manufacturing apparatus comprising a drying section that dries the web to produce a sheet. An endless belt is arranged from the watering section to the drying section, and the web generated in the watering 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, and examples thereof include a dehydration method usually used in the production of paper. Among these, a method of dehydrating with a long net, a circular net, an inclined wire or the like and then further dehydrating with a roll press is preferable. Further, the drying method used in the papermaking process is not particularly limited, and examples thereof include a method used in the production of paper. Among these, a drying method using a cylinder dryer, a Yankee dryer, hot air drying, a near infrared heater, an infrared heater, or the like is more preferable.

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

(Pattern formation method)
The base material for pattern formation of the present invention is a base material used in the pattern forming step. As a pattern forming method, for example, a metal such as copper, silver, gold, aluminum, magnesium or an alloy thereof or an alloy thereof is vapor-deposited or pressure-bonded on the resin layer to form these metals or an alloy film, and then a predetermined shape is formed. A method of etching so as to be obtained can be mentioned. At this time, a step of modifying the resin layer may be provided before the metal or the like is vapor-deposited or crimped. For example, the region where a metal or the like is vapor-deposited or pressure-bonded may be controlled by providing a step of performing a hydrophilic treatment or a hydrophobic treatment on a part of the resin layer.
Further, a self-assembling composition such as polystyrene-polymethylmethacrylate (PS-PMMA) is applied on the resin layer and subjected to an annealing treatment to form a pattern, or an acrylic resin, a novolac resin, or a polyphenylene sulfide resin is formed on the resin layer. The pattern may be formed by applying a photoresist such as, partially exposing the resin, and then removing unnecessary portions with a rinsing solution.

The features of the present invention will be described in more detail with reference to Examples and Comparative Examples. The materials, amounts used, ratios, treatment contents, treatment procedures, etc. shown in the following examples can be appropriately changed as long as they do not deviate from the gist of the present invention. Therefore, the scope of the present invention should not be construed as limiting by the specific examples shown below.

<Manufacturing example 1>
(Manufacturing of phosphorylated pulp)
As raw material pulp, softwood kraft pulp made by Oji Paper (solid content 93% by mass, basis weight 208 g / m ² sheet form, Canadian standard drainage degree (CSF) measured according to JIS P 8121 by separation is 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. To obtain a chemical-impregnated pulp. Next, the obtained chemical-impregnated pulp was heated in a hot air dryer at 165 ° C. for 200 seconds to introduce a phosphoric acid group into the cellulose in the pulp to obtain a phosphorylated pulp.

Then, the obtained phosphorylated pulp was washed. The washing treatment is carried out by repeating the operation of pouring 10 L of ion-exchanged water into 100 g (absolute dry mass) of phosphorylated pulp, stirring the pulp dispersion liquid so that the pulp is uniformly dispersed, and then filtering and dehydrating the pulp. went. When the electrical conductivity of the filtrate became 100 μS / cm or less, the washing end point was set.

Next, the phosphorylated pulp after washing was subjected to alkali treatment (neutralization treatment) as follows. First, the washed phosphorylated pulp was diluted with 10 L of ion-exchanged water, and then a 1N aqueous sodium hydroxide solution was added little by little with 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 phosphorylated pulp subjected to alkali treatment (neutralization treatment).

Next, the phosphorylated pulp after the neutralization treatment was subjected to the above washing treatment. The infrared absorption spectrum of the phosphorylated pulp thus obtained was measured using FT-IR. As a result, absorption of the phosphate group based on P = O was observed around 1230 cm ^-1 , and it was confirmed that the phosphate group was added to the pulp. Further, when the obtained phosphorylated pulp was tested and analyzed by an X-ray diffractometer, it was found at two positions, 2θ = 14 ° or more and 17 ° or less and 2θ = 22 ° or more and 23 ° or less. A typical peak was confirmed, and it was confirmed that it had cellulose type I crystals.

(Defibration treatment)
Ion-exchanged water was added to the obtained phosphorylated pulp to prepare a slurry having a solid content concentration of 2% by mass. This slurry was treated four times at a pressure of 200 MPa with a wet atomizing device (manufactured by Sugino Machine Limited, Starburst) to obtain a fine fibrous cellulose dispersion (A) containing fine fibrous cellulose.

By X-ray diffraction, it was confirmed that this fine fibrous cellulose maintained the cellulose type I crystal. Moreover, when the fiber width of the fine fibrous cellulose was measured using a transmission electron microscope, it was 3 to 5 nm. The amount of phosphoric acid group (first dissociated acid amount) measured by the measuring method described later was 1.45 mmol / g. The total amount of dissociated acid was 2.45 mmol / g.

(Measurement of phosphorus oxo acid group amount)
The amount of phosphorus oxo acid groups in the fine fibrous cellulose (equal to the amount of phosphorus oxo acid groups in the phosphorus oxo oxide pulp) is adjusted by adding ion-exchanged water to the fine fibrous cellulose dispersion containing the target fine fibrous cellulose. It was adjusted to 0.2% by mass, treated with an ion exchange resin, and then titrated with an alkali.
For the treatment with the ion exchange resin, a strongly acidic ion exchange resin (Amberjet 1024; manufactured by Organo Corporation, which has been conditioned) with a volume of 1/10 is added to the fine fibrous cellulose-containing slurry and shaken for 1 hour. After that, the resin and the slurry were separated by pouring on a mesh having a mesh size of 90 μm.
In addition, titration using alkali changes the pH value indicated by the slurry while adding 10 μL of 0.1 N sodium hydroxide aqueous solution to the fine fibrous cellulose-containing slurry treated with an ion exchange resin every 5 seconds. It was done by measuring. The titration was carried out while blowing nitrogen gas into the slurry from 15 minutes before the start of the titration. In this neutralization titration, two points are observed where the increment (differential value of pH with respect to the amount of alkali dropped) becomes maximum in the curve plotting the measured pH with respect to the amount of alkali added. Of these, the maximum point of the increment obtained first when alkali is added is called the first end point, and the maximum point of the increment obtained next is called the second end point (FIG. 2). The amount of alkali required from the start of the titration to the first end point is equal to the amount of the first dissociated acid in the slurry used for the titration. Further, the amount of alkali required from the start of titration to the second end point becomes 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 divided by the solid content (g) in the slurry to be titrated is the amount of phosphorus oxo 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).

<Manufacturing example 2>
(Manufacturing of TEMPO oxidized pulp)
As the raw material pulp, softwood kraft pulp (undried) manufactured by Oji Paper Co., Ltd. was used. Alkaline TEMPO oxidation treatment was carried out on this raw material pulp as follows. First, the above-mentioned raw material pulp equivalent to 100 parts by mass of dry mass, 1.6 parts by mass of TEMPO (2,2,6,6-tetramethylpiperidin-1-oxyl), and 10 parts by mass of sodium bromide are added to 10000 parts by mass of water. It was dispersed in the parts. Then, a 13 mass% sodium hypochlorite aqueous solution was added to 1.0 g of pulp so as to be 3.8 mmol, and the reaction was started. During the reaction, a 0.5 M aqueous sodium hydroxide solution was added dropwise to keep the pH at 10 or more and 10.5 or less, and the reaction was considered to be completed when no change was observed in the pH.

Next, the obtained TEMPO oxide pulp was washed. The washing treatment is carried out by dehydrating the pulp slurry after TEMPO oxidation to obtain a dehydrated sheet, pouring 5000 parts by mass of ion-exchanged water, stirring and uniformly dispersing, and then repeating the operation of filtration and dehydration. It was. When the electrical conductivity of the filtrate became 100 μS / cm or less, the washing end point was set.

When the obtained TEMPO oxide pulp was tested and analyzed by an X-ray diffractometer, it was typical at two positions, 2θ = 14 ° or more and 17 ° or less and 2θ = 22 ° or more and 23 ° or less. Peak was confirmed, and it was confirmed that it had cellulose type I crystals.

(Defibration treatment)
Ion-exchanged water was added to the obtained TEMPO oxidized pulp to prepare a slurry having a solid content concentration of 2% by mass. This slurry was treated four times at a pressure of 200 MPa with a wet atomizing device (manufactured by Sugino Machine Limited, Starburst) to obtain a fine fibrous cellulose dispersion (B) containing fine fibrous cellulose. By X-ray diffraction, it was confirmed that this fine fibrous cellulose maintained the cellulose type I crystal. Moreover, when the fiber width of the fine fibrous cellulose was measured using a transmission electron microscope, it was 3 to 5 nm. The amount of carboxy group measured by the measuring method described later was 1.30 mmol / g.

(Measurement of carboxy group amount)
The carboxy group amount of the fine fibrous cellulose (equal to the carboxy group amount of the TEMPO oxide pulp) is set to 0 by adding ion-exchanged water to the fine fibrous cellulose dispersion containing the target fine fibrous cellulose. It was measured at 2% by mass, treated with an ion exchange resin, and then titrated with an alkali.
The treatment with an ion exchange resin is carried out by adding a 1/10 volume of a strongly acidic ion exchange resin (Amberjet 1024; manufactured by Organo Corporation, conditioned) to a slurry containing 0.2% by mass of fine fibrous cellulose for 1 hour. After the shaking treatment, the resin and the slurry were separated by pouring onto a mesh having a mesh size of 90 μm.
Further, the titration using alkali was performed by measuring the change in the pH value indicated by the slurry while adding a 0.1 N sodium hydroxide aqueous solution to the fibrous cellulose-containing slurry treated with the ion exchange resin. .. By observing the change in pH while adding an aqueous sodium hydroxide solution, a titration curve as shown in FIG. 3 can be obtained. As shown in FIG. 3, in this neutralization titration, there is one point in which the increment (differential value of pH with respect to the amount of alkaline drop) becomes maximum in the curve plotting the measured pH with respect to the amount of alkali added. Observed. The maximum point of this increment is called the first end point. Here, the region from the start of titration to the first end point in FIG. 3 is referred to as a first region. The amount of alkali required in the first region is equal to the amount of carboxy groups in the slurry 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 fine fibrous cellulose-containing slurry to be titrated, so that the amount of carboxy group introduced (mmol / g). ) Was calculated.
The above-mentioned amount of carboxy group introduced (mmol / g) is the amount of substituents per 1 g of mass of fibrous cellulose when the counterion of the carboxy group is hydrogen ion (H ⁺ ) (hereinafter, the amount of carboxy group (acid). Type)) is shown.

<Manufacturing example 3>
(Manufacturing of subphosphorylated pulp)
The same procedure as in Production Example 1 was carried out except that 33 parts by mass of phosphorous acid (phosphonic acid) was used instead of ammonium dihydrogen phosphate to obtain phosphorylated pulp.

The infrared absorption spectrum of the obtained subphosphorylated pulp was measured using FT-IR. As a result, absorption based on P = O of the phosphonic acid group, which is a tautomer of the phosphite group, was observed around 1210 cm ^-1 , and the phosphite group (phosphonic acid group) was added to the pulp. Was confirmed. Further, when the obtained subphosphorylated pulp was tested and analyzed by an X-ray diffractometer, two positions were found: 2θ = 14 ° or more and 17 ° or less and 2θ = 22 ° or more and 23 ° or less. A typical peak was confirmed in, and it was confirmed that it had cellulose type I crystals.

(Defibration treatment)
Ion-exchanged water was added to the obtained subphosphorylated pulp to prepare a slurry having a solid content concentration of 2% by mass. This slurry was treated four times at a pressure of 200 MPa with a wet atomizing device (manufactured by Sugino Machine Limited, Starburst) to obtain a fine fibrous cellulose dispersion (C) containing fine fibrous cellulose. By X-ray diffraction, it was confirmed that this fine fibrous cellulose maintained the cellulose type I crystal. Moreover, when the fiber width of the fine fibrous cellulose was measured using a transmission electron microscope, it was 3 to 5 nm. The amount of phosphite group (first dissociated acid amount) measured by the above-mentioned method for measuring the amount of phosphorous acid group was 1.51 mmol / g. The total amount of dissociated acid was 1.54 mmol / g.

<Example 1>
(Dissolution of polyvinyl alcohol)
Polyvinyl alcohol (PVA) (manufactured by Kuraray Co., Ltd., Poval 105, degree of polymerization: 500, degree of saponification: 98 to 99 mol%) was added to ion-exchanged water so as to be 0.5% by mass, and the temperature was 95 ° C. for 1 hour. The mixture was stirred and dissolved to obtain an aqueous polyvinyl alcohol solution.

(Sheet)
The concentration of the fine fibrous cellulose dispersion (A) was adjusted by adding ion-exchanged water so that the solid content concentration was 0.5% by mass. Next, an aqueous polyvinyl alcohol solution was added to 55 parts by mass of the fine fibrous cellulose so that the amount of polyvinyl alcohol was 45 parts by mass, and the mixture was stirred. Further, the liquid after mixing was weighed so that the finished basis weight of the sheet was 50 g / m ² , developed on a commercially available acrylic plate, and dried in a dryer at 50 ° C. for 24 hours. A 150 mm square dammed plate was placed on the acrylic plate so as to have a predetermined basis weight. By the above procedure, a fine fibrous cellulose-containing sheet was obtained.

(Lamination of resin layer)
Acrylic resin graft-polymerized with acryloyl group having a hydroxyl group (manufactured by Taisei Fine Chemicals Co., Ltd., Acryt 8KX-012C, solid content concentration is 39% by mass) 100 parts by mass, and polyisocyanate compound (manufactured by Asahi Kasei Chemicals Co., Ltd., TPA-100) 38 parts by mass A resin composition was obtained by mixing 100 parts by mass of the methyl ethyl ketone. Next, the resin composition was applied to the surface of the fine fibrous cellulose-containing sheet in contact with the acrylic plate with a bar coater, and then heated at 100 ° C. for 1 hour to cure and laminate the resin layer. Further, a resin layer was laminated on the opposite surface of the fine fibrous cellulose-containing sheet in the same procedure. The thickness of the resin layer was 1 μm per side, and the basis weight after lamination was 53 g / m ² . A laminated sheet (base material for pattern formation) was obtained by the above procedure.

<Example 2>
In the sheet formation of Example 1, the same as in Example 1 except that the amount of fine fibrous cellulose added was 75 parts by mass and the amount of polyvinyl alcohol added was changed to 25 parts by mass, and the laminated sheet (pattern forming group) was used. Material) was obtained. The resin layer after lamination was 53 g / m ² .

<Example 3>
(Lamination of resin layer)
9. 100 parts by mass of urethane acrylate copolymer (Acryt 8UA-347A, manufactured by Taisei Fine Chemicals Co., Ltd.), isocyanurate compound (Duranate TPA-100, manufactured by Asahi Kasei Chemicals Co., Ltd.) having a mass ratio of urethane unit / acrylic unit of 2/8. 7 parts by mass were mixed to obtain a resin composition. Next, the resin composition was applied to the surface of the fine fibrous cellulose-containing sheet obtained in Example 2 in contact with the acrylic plate with a bar coater, and then heated at 100 ° C. for 1 hour to cure the resin. The layers were laminated. Further, a resin layer was laminated on the opposite surface of the sheet in the same procedure. The thickness of the resin layer was 1 μm per side, and the basis weight after lamination was 53 g / m ² . A laminated sheet (base material for pattern formation) was obtained by the above procedure.

<Example 4>
In the sheet formation of Example 2, a laminated sheet (pattern-forming base material) was obtained in the same manner as in Example 2 except that the fine fibrous cellulose dispersion (B) was used instead of the fine fibrous cellulose dispersion (A). ) Was obtained. The basis weight of the resin layer after lamination was 53 g / m ² .

<Example 5>
In the sheet formation of Example 2, a laminated sheet (pattern-forming base material) was obtained in the same manner as in Example 2 except that the fine fibrous cellulose dispersion (C) was used instead of the fine fibrous cellulose dispersion (A). ) Was obtained. The basis weight of the resin layer after lamination was 53 g / m ² .

<Comparative example 1>
In the sheet formation of Example 2, the fine fibrous cellulose-containing sheet was used for the subsequent measurement and evaluation without laminating the resin layer.

<Comparative example 2>
In the sheet formation of Example 1, a polyvinyl alcohol aqueous solution was added to 40 parts by mass of fine fibrous cellulose so that the amount of polyvinyl alcohol was 30 parts by mass, and after stirring, 30 parts by mass of ethylene glycol (EG) (molecular weight). 65) was added and stirred. Other procedures were the same as in Example 1 to obtain a laminated sheet. The basis weight of the resin layer after lamination was 53 g / m ² .

<Comparative example 3>
(Porous sheet)
In the sheet formation of Example 1, the liquid after mixing is weighed, developed on a commercially available acrylic plate, dried in a dryer at 50 ° C., and then the sheet is dried and can be peeled off from the acrylic plate. After confirming that it became, the sheet was picked up in a wet state. The wet sheet was immersed in isobutyl alcohol and allowed to stand for 10 minutes to carry out the porosification treatment. Then, the wet sheet was allowed to stand on the plastic wire and dried in a dryer at 100 ° C. for 1 hour. At this time, the surface that was in contact with the acrylic plate was brought into contact with the plastic wire. By the above procedure, a porous fine fibrous cellulose-containing sheet was obtained.

(Impregnated with resin)
9. 100 parts by mass of urethane acrylate copolymer (Acryt 8UA-347A, manufactured by Taisei Fine Chemicals Co., Ltd.), isocyanurate compound (Duranate TPA-100, manufactured by Asahi Kasei Chemicals Co., Ltd.) having a mass ratio of urethane unit / acrylic unit of 2/8. 7 parts by mass were mixed to obtain a resin composition. Next, the fine fibrous cellulose-containing sheet was immersed in the resin composition and allowed to stand for 10 minutes. Then, this sheet was taken out, a piece on the sheet was fixed to a net shelf in a dryer with a clip and hung, and heated at 100 ° C. for 1 hour to cure the resin composition. A resin-impregnated sheet was obtained by the above procedure. The basis weight of the obtained sheet was 60 g / m ² .

<Measurement>
The laminated sheets obtained in Examples 1 to 5 and the fine fibrous cellulose-containing sheets, laminated sheets, and resin-impregnated sheets obtained in Comparative Examples 1 to 3 were measured according to the following methods. In the following, the laminated sheet, the fine fibrous cellulose-containing sheet, the laminated sheet, and the resin-impregnated sheet are simply referred to as sheets.

(Content of fine fibrous cellulose)
The content of fine fibrous cellulose in the sheet was calculated according to the following formula.
The content of fine fibrous cellulose _{(wt%) = 100 × (G A} / G B) × (C / 100)
Here, G _A is the basis weight of the fine fibrous cellulose-containing sheet, G _B is the basis weight of the sheet after impregnation of the laminate, or resin in the resin layer, C is, microfibrous cellulose-containing sheet It is the amount of fine fibrous cellulose compounded in.

(density)
The basis weight of the sheet was divided by the thickness to obtain the density of the sheet. The thickness of the sheet was measured with a stylus type thickness gauge (Millitron 1202D manufactured by Marl.).

(Surface roughness)
Using an atomic force microscope (NanoScope IIIa, manufactured by Veeco), the arithmetic mean roughness of the surface of the sheet (resin layer surface) of 10 μm square was measured. When the measured sheet is a laminated sheet, the measurement surface is the surface of the resin layer, and the surface of the resin layer is the surface of the resin layer laminated on the surface on the side where the base layer is in contact with the acrylic plate.

(Tensile modulus)
The tensile elastic modulus of the sheet was measured using a tensile tester Tensilon (manufactured by A & D Co., Ltd.) in accordance with JIS P 8113. The elastic modulus is a value calculated from the maximum positive slope value in the SS curve. When measuring the tensile elastic modulus, a test piece prepared at 23 ° C. and a relative humidity of 50% for 24 hours was used.

(Water contact angle)
According to JIS R 3257, the water contact angle of the surface of the sheet (resin layer surface) was measured using a dynamic water contact angle tester (1100 DAT manufactured by Fibro). When the measured sheet is a laminated sheet, the measurement surface is the surface of the resin layer, and the surface of the resin layer is the surface of the resin layer laminated on the surface on the side where the base layer is in contact with the acrylic plate. At the time of measurement, 4 μL of distilled water was dropped on the surface of the resin layer, and the water contact angle 30 seconds after the dropping was used as the measured value.

(Haze)
According to JIS K 7136, the haze of the sheet was measured using a haze meter (HM-150 manufactured by Murakami Color Technology Research Institute).

(Shrinkage factor)
The sheet was cut into a 3 mm width × 30 mm length by a laser cutter. Set this test piece in a thermomechanical analyzer (TMA7100, manufactured by Hitachi High-Tech Science Co., Ltd.), set the chuck distance to 20 mm, load 10 g, and nitrogen atmosphere in tension mode, and raise the temperature from room temperature to 110 ° C at 5 ° C / min. After that, it was held for 1 hour. The dimensional change rate at this time was taken as the shrinkage rate of the sheet.
Shrinkage rate (%) = | BA | / A × 100
A is the inter-chuck distance (mm) in the initial state (temperature is room temperature) set in the analyzer, and B is the inter-chuck distance (mm) after the temperature is raised at 110 ° C. and held for 1 hour.

<Evaluation>
The laminated sheets obtained in Examples 1 to 5 and the fine fibrous cellulose-containing sheets, laminated sheets, and resin-impregnated sheets obtained in Comparative Examples 1 to 3 were evaluated according to the following methods.

(Evaluation of patterning property)
The sheet was allowed to stand in an environment having a temperature of 23 ° C. and a relative humidity of 50% for 24 hours, cut into 50 mm squares, and allowed to stand on a stage of an ion sputtering apparatus (JFC-3000FC manufactured by JEOL Ltd.). At this time, when the sheet was a laminated sheet, it was allowed to stand so that the resin layer was on the upper surface. Next, a photomask having a line / space (L / S) of 20 μm / 20 μm (manufactured by Mitani Micronics Co., Ltd., 5 inch size, made of synthetic quartz) was placed on this sheet. At this time, a shim tape (manufactured by MISUMI, thickness 20 μm, manufactured by SUS) was used, and the gap between the sheet and the photomask was set to be 20 μm. Then, gold was deposited by the above ion sputtering apparatus. At this time, the thickness of the deposited gold was set to be 20 nm. After depositing gold, the shim tape and photomask were removed, and the width of the gold vapor deposition line formed on the sheet was observed and measured with an optical microscope. Then, the patterning property was evaluated according to the following criteria.
◯: The range in which gold is vapor-deposited is within the range of 20 ± 5 μm ×: The range in which gold is vapor-deposited exceeds the range of 20 ± 5 μm.

(Evaluation of patterning property after high temperature and high humidity treatment)
The sheet was cut into 50 mm squares and allowed to stand in an environment having a temperature of 60 ° C. and a relative humidity of 90% for 24 hours. Next, gold was deposited on this sheet by the same method as described above (evaluation of patterning property). The sheet after vapor deposition was observed with an optical microscope, and the patterning property was evaluated according to the following criteria.
◯: The range in which gold is vapor-deposited is within the range of 20 ± 5 μm ×: The range in which gold is vapor-deposited exceeds the range of 20 ± 5 μm.

As is clear from Table 1, the laminated sheet (pattern-forming base material) containing the base layer containing the fibrous cellulose and the resin layer obtained in Examples showed good patterning properties. In particular, the pattern-forming substrates of Examples 1 to 3 and Example 5 have particularly high transparency (low haze), and it is presumed that they are highly compatible when performing optical positioning in the patterning process. It was.

On the other hand, in the sheet not containing the resin layer obtained in Comparative Example 1, the water contact angle of the sheet was small, the shrinkage rate was large, and the patterning property result was poor.
The sheet containing the low molecular weight compound obtained in Comparative Example 2 had good patterning properties immediately after production, but the low molecular weight components were exposed on the sheet surface due to exposure under high temperature and high humidity, and thus the high temperature and high humidity treatment was performed. Later patterning was poor.
In the sheet obtained in Comparative Example 3 which was made porous and then impregnated with resin, the surface roughness (arithmetic mean roughness) was large and the patterning property was poor.

2 Base layer 6 Resin layer 10 Base material for pattern formation

Claims (11)

A base material for pattern formation containing a base layer containing fibrous cellulose having a fiber width of 1000 nm or less and a resin layer.
A base material for pattern formation in which the content of a low molecular weight compound having a molecular weight of 400 or less in the base layer is less than 20% by mass with respect to the total mass of the base layer. The pattern-forming substrate according to claim 1, which has a density of 1.00 g / cm ³ or more. The pattern-forming base material according to claim 1 or 2, wherein the tensile elastic modulus is 2.0 GPa or more. The pattern-forming base material according to any one of claims 1 to 3, wherein the haze is 10.0% or less. The pattern-forming substrate according to any one of claims 1 to 5, wherein the shrinkage rate after holding the pattern-forming substrate in a nitrogen atmosphere at a temperature of 110 ° C. for 1 hour is 1.2% or less. .. The pattern-forming base material according to any one of claims 1 to 5, wherein the arithmetic average roughness of the surface of the resin layer is 100 nm or less. The pattern-forming base material according to any one of claims 1 to 6, wherein the water contact angle on the surface of the resin layer is 60 ° or more. The pattern-forming base material according to any one of claims 1 to 7, wherein the content of the fibrous cellulose is 10% by mass or more with respect to the total mass of the pattern-forming base material. The pattern-forming base material according to any one of claims 1 to 8, wherein the fibrous cellulose has a phosphoric acid or a substituent derived from the phosphoric acid. The pattern-forming base material according to any one of claims 1 to 9, wherein the resin layer contains a hydrophobic resin. The pattern-forming base material according to any one of claims 1 to 10, wherein the base layer further contains a hydrophilic polymer.

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