JP6620567B2 - Laminate and method for producing laminate - Google Patents

Description

  The present invention relates to a laminate and a method for producing the laminate.

  In recent years, materials that use reproducible natural fibers have attracted attention due to the substitution of petroleum resources and the growing environmental awareness. Among natural fibers, fibrous cellulose having a fiber diameter of 10 μm or more and 50 μm or less, in particular, fibrous cellulose (pulp) derived from wood has been widely used mainly as a paper product so far.

  As the fibrous cellulose, fine fibrous cellulose having a fiber diameter of 1 μm or less is also known. Moreover, the composite_body | complex containing the sheet | seat comprised from such a fine fibrous cellulose and a fine fibrous cellulose containing sheet | seat and a resin layer is developed. In the sheet | seat and composite containing fine fibrous cellulose, since the contact point of fibers increases remarkably, it is known that tensile strength etc. will improve large. It is also known that transparency is greatly improved when the fiber width is shorter than the wavelength of visible light.

  In a composite including a fine fibrous cellulose-containing sheet and a resin layer, it has been studied to improve the adhesion between the fine fibrous cellulose-containing sheet and the resin layer. For example, in Patent Document 1, when a polycarbonate sheet is heated and fused to a fine fibrous cellulose-containing sheet to form a laminate, by using a fine fibrous cellulose-containing sheet containing a primer treatment liquid such as an acrylic primer. Increasing adhesion is being studied. Moreover, in patent document 2, laminating | stacking a fine fibrous cellulose containing sheet | seat and a resin layer via an contact bonding layer is examined. In the example of Patent Document 2, a polyurethane-based adhesive is used as an adhesive constituting the adhesive layer.

JP 2010-023275 A JP 2014-065837 A

However, in the conventional laminate, the adhesion between the fine fibrous cellulose-containing sheet (fiber layer) and the resin layer is not sufficient, and further improvements may be required in the usage mode. Moreover, in the conventional laminated body, the adhesiveness at the time of bending stress provision may be inferior, and the improvement was calculated | required.
Therefore, the present inventors are a laminate having a fine fibrous cellulose-containing sheet (fiber layer) and a resin layer in order to solve such problems of the prior art, and have better adhesion, In addition, studies have been conducted for the purpose of providing a laminate having excellent adhesion when bending stress is applied.

As a result of earnest studies to solve the above problems, the present inventors have found that a laminate having a fiber layer containing fibrous cellulose having a fiber width of 1000 nm or less, an adhesive layer, and a resin layer in this order. In the above, it was found that the adhesiveness of the fiber layer and the resin layer can be improved by constituting the adhesive layer from a predetermined resin type.
Specifically, the present invention has the following configuration.

[1] A laminate having a fiber layer containing fibrous cellulose having a fiber width of 1000 nm or less, an adhesive layer containing a urethane (meth) acrylate resin, and a resin layer in this order.
[2] The laminate according to [1], wherein the resin layer includes at least one selected from a polycarbonate resin and an acrylic resin.
[3] The resin layer includes a first layer disposed on the adhesive layer side, and a second layer disposed on one surface side of the first layer and opposite to the adhesive layer, One layer includes an acrylic resin, and the second layer includes a polycarbonate resin according to [1] or [2].
[4] The laminate according to [3], wherein the first layer includes an alkyl (meth) acrylate resin.
[5] The laminate according to [3], wherein the first layer includes an epoxy (meth) acrylate resin.
[6] The laminate according to any one of [3] to [5], wherein the resin layer is a coextruded film having a first layer and a second layer.
[7] The urethane (meth) acrylate resin contained in the adhesive layer includes a urethane unit and an acrylic unit, the content (mass%) of the urethane unit is P, and the content (mass%) of the acrylic unit is Q. In this case, the laminate according to any one of [1] to [6], wherein P / Q is 0.1 or more and 0.9 or less.
[8] The laminate according to any one of [1] to [7], wherein the density of the fiber layer is 1.0 g / cm ³ or more.
[9] A step of obtaining a fiber layer containing fibrous cellulose having a fiber width of 1000 nm or less and a resin composition containing urethane (meth) acrylate are applied on at least one surface of the fiber layer to form an adhesive layer. And a step of laminating a resin layer on one surface of the adhesive layer opposite to the fiber layer.
[10] The resin layer includes a first layer disposed on the adhesive layer side, and a second layer disposed on one surface side of the first layer and on the opposite side of the adhesive layer. One layer includes an epoxy (meth) acrylate resin, the second layer includes a polycarbonate resin, and the resin layer is formed by coating an epoxy (meth) acrylate-containing composition on the second layer. The manufacturing method of the laminated body as described in [9].
[11] The resin layer includes a first layer disposed on the adhesive layer side, and a second layer disposed on one surface side of the first layer and opposite to the adhesive layer, One layer includes an alkyl (meth) acrylate resin, the second layer includes a polycarbonate resin, and the resin layer is formed by coextrusion of the first layer and the second layer. Body manufacturing method.

  ADVANTAGE OF THE INVENTION According to this invention, the laminated body with which the adhesiveness of the fiber layer containing a fine fibrous cellulose and a resin layer was improved can be obtained. Furthermore, according to this invention, the laminated body excellent also in the adhesiveness at the time of bending stress provision can be obtained. Since the laminated body of this invention is a laminated body excellent in adhesiveness, it can be applied to various uses.

FIG. 1 is a cross-sectional view illustrating the configuration of the laminate of the present invention. FIG. 2 is a cross-sectional view illustrating the configuration of the laminate of the present invention. FIG. 3 is a cross-sectional view illustrating the configuration of the laminate of the present invention. FIG. 4 is a graph showing the relationship between the amount of NaOH dripped with respect to the fiber material and the electrical conductivity.

  Hereinafter, the present invention will be described in detail. The description of the constituent elements described below may be made based on representative embodiments and specific examples, but the present invention is not limited to such embodiments. In the present specification, “(meth) acrylate” means that both “acrylate” and “methacrylate” are included.

(Laminate)
The present invention has a fiber layer containing fibrous cellulose having a fiber width of 1000 nm or less (hereinafter also referred to as fine fibrous cellulose), an adhesive layer containing urethane (meth) acrylate resin, and a resin layer in this order. It relates to a laminate.
Since the laminated body of this invention has the said structure, it is excellent in the adhesiveness of the fiber layer and fibrous layer containing fibrous cellulose whose fiber width is 1000 nm or less. Moreover, the laminated body of this invention can exhibit the outstanding adhesiveness also at the time of bending stress provision.

  FIG. 1 is a cross-sectional view illustrating the configuration of the laminate of the present invention. As shown in FIG. 1, the laminate 10 of the present invention has a structure in which a fiber layer 2, an adhesive layer 4, and a resin layer 6 are laminated in this order. The fiber layer 2 and the resin layer 6 are bonded via an adhesive layer 4.

  The laminate of the present invention may have at least one fiber layer 2, an adhesive layer 4 and a resin layer 6, but may have two or more fiber layers 2; It may have two or more layers, and may have two or more resin layers 6. For example, FIG. 2 shows a laminate 10 having two resin layers 6 and two adhesive layers 4. As shown in FIG. 2, the two resin layers 6 may be provided on both surfaces of the fiber layer 2. In this case, it is preferable that the adhesive layers 4 are provided on both surfaces of the fiber layer 2, and the resin layer 6 is laminated via the adhesive layer 4. In the configuration as shown in FIG. 2, the fiber layer 2 may be a multi-layer fiber layer.

  The total thickness of the laminate of the present invention is not particularly limited, but is preferably 50 μm or more, more preferably 100 μm or more, and further preferably 200 μm or more. Moreover, it is preferable that the whole thickness of a laminated body is 20 mm or less. The thickness of the laminate is preferably adjusted as appropriate according to the application.

  The thickness of the fiber layer of the laminate is preferably 5 μm or more, more preferably 10 μm or more, and further preferably 20 μm or more. The thickness of the fiber layer is preferably 500 μm or less, more preferably 200 μm or less, and further preferably 100 μm or less. Here, the thickness of the fiber layer constituting the laminate is measured by cutting a section of the laminate with an ultramicrotome UC-7 (manufactured by JEOL), and observing the section with an electron microscope, a magnifying glass, or visually. Value. When the laminated body includes a plurality of fiber layers, the total thickness of the fiber layers is preferably within the above range.

  The thickness of the adhesive layer of the laminate is preferably 0.1 μm or more, more preferably 1 μm or more, and further preferably 2 μm or more. Further, the thickness of the adhesive layer is preferably 50 μm or less, more preferably 20 μm or less, and further preferably 10 μm or less. Here, the thickness of the adhesive layer constituting the laminate is measured by cutting a section of the laminate with an ultramicrotome UC-7 (manufactured by JEOL), and observing the section with an electron microscope, a magnifying glass, or visually. Value. When the laminated body includes a plurality of adhesive layers, the total thickness of the adhesive layers is preferably within the above range.

  Further, the thickness of the resin layer of the laminate is preferably 10 μm or more, more preferably 20 μm or more, further preferably 50 μm or more, still more preferably 100 μm or more, and 200 μm or more. It is particularly preferred. The thickness of the resin layer is preferably 15000 μm or less, more preferably 5000 μm or less, and even more preferably 500 μm or less. Here, the thickness of the resin layer constituting the laminate is measured by cutting out a cross section of the laminate using an ultramicrotome UC-7 (manufactured by JEOL), and observing the cross section with an electron microscope, a magnifying glass, or visually. Value. When the laminate includes a plurality of resin layers, the total resin layer thickness is preferably within the above range.

  In the laminated body of the present invention, the thickness of the resin layer is preferably 30% or more, more preferably 100% or more of the thickness of the fiber layer. When the laminate has a plurality of at least one of a fiber layer and a resin layer, the ratio of the total thickness of the resin layer to the total thickness of the fiber layer (the total thickness of the resin layer / the thickness of the fiber layer) Is preferably 0.5 or more. By setting the ratio of the total thickness of the resin layer to the total thickness of the fiber layers in the above range, the mechanical strength of the laminate can be increased.

  The total light transmittance of the laminate is preferably 60% or more, more preferably 65% or more, further preferably 70% or more, and particularly preferably 85% or more. By making the total light transmittance of a laminated body into the said range, it becomes easy to apply the laminated body of this invention to the use to which transparent glass was applied conventionally. Here, the total light transmittance is a value measured using a haze meter (manufactured by Murakami Color Research Laboratory Co., Ltd., HM-150) in accordance with JIS K 7361.

  The haze of the laminate is preferably 20% or less, more preferably 15% or less, further preferably 10% or less, and particularly preferably 5% or less. The lower the haze, the easier it is to apply the laminate of the present invention to applications where conventionally transparent glass has been applied. Here, haze is a value measured using a haze meter (manufactured by Murakami Color Research Laboratory Co., Ltd., HM-150) in accordance with JIS K 7136.

  The tensile elastic modulus at 23 ° C. and 50% relative humidity of the laminate is preferably 2.5 GPa or more, more preferably 5.0 GPa or more, and further preferably 10 GPa or more. Further, the tensile elastic modulus at 23 ° C. and 50% relative humidity of the laminate is preferably 30 GPa or less, more preferably 25 GPa or less, and further preferably 20 GPa or less. The tensile elastic modulus of the laminate is a value measured in accordance with JIS P8113.

(Resin layer)
The resin layer is a layer mainly composed of a resin such as a natural resin or a synthetic resin. Here, a main component refers to the component contained 50 mass% or more with respect to the total mass of a resin layer. The content of the resin is preferably 60% by mass or more, more preferably 70% by mass or more, further preferably 80% by mass or more, and 90% by mass with respect to the total mass of the resin layer. The above is particularly preferable. In addition, content of resin can also be 100 mass%, and may be 95 mass% or less.

  Examples of natural resins include rosin 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, and acrylic resin. Among these, the synthetic resin is preferably at least one selected from polycarbonate resin and acrylic resin, and more preferably polycarbonate resin. The acrylic resin is preferably at least one selected from polyacrylonitrile and poly (meth) acrylate.

  Examples of the polycarbonate resin constituting the resin layer include an aromatic polycarbonate resin and an aliphatic polycarbonate resin. These specific polycarbonate resins are known, and examples thereof include polycarbonate resins described in JP2010-023275A.

The resin layer may have a single layer structure or a multilayer structure. When the resin layer has a multilayer structure, the resin layer includes a first layer disposed on the adhesive layer side and a second layer disposed on one surface side of the first layer and on the opposite side of the adhesive layer. It is preferable to have.
FIG. 3 is a cross-sectional view illustrating the configuration of the laminate 10 when the resin layer 6 includes the first layer 11 and the second layer 12. As shown in FIG. 3, the first layer 11 is laminated so as to be in contact with the adhesive layer 4 and constitutes the laminate 10.

  When the resin layer has a multilayer structure, the first layer preferably includes an acrylic resin. The second layer preferably contains at least one selected from polycarbonate resin and acrylic resin, and more preferably contains polycarbonate resin. When the resin layer has the multilayer structure as described above, the adhesion between the resin layer and the fiber layer bonded via the adhesive layer can be more effectively increased.

  When the resin layer has the first layer and the second layer as described above, the first layer preferably contains an acrylic resin. The acrylic resin is, for example, a polymer of an acrylic monomer having at least one selected from alkyl groups, hydroxyl groups, epoxy groups, alkoxy groups, ethylene oxide groups, amino groups, amide groups, carboxyl groups, urethane groups, and phenyl groups. Preferably there is. Among these, the acrylic resin is more preferably a polymer of an acrylic monomer having at least one selected from an alkyl group and an epoxy group. That is, the first layer preferably includes at least one selected from alkyl (meth) acrylate resins and epoxy (meth) acrylate resins.

  Examples of the alkyl (meth) acrylate include methyl (meth) acrylate, ethyl (meth) acrylate, isopropyl (meth) acrylate, lauryl (meth) acrylate, stearyl (meth) acrylate, butyl (meth) acrylate, and hexyl (meth). Acrylate, cyclohexyl (meth) acrylate, 2-ethylhexyl (meth) acrylate, isoamyl (meth) acrylate, isooctyl (meth) acrylate, n-octyl (meth) acrylate, dodecyl (meth) acrylate, isobutyl (meth) acrylate, etc. It is done. Among them, the alkyl (meth) acrylate is preferably methyl (meth) acrylate or ethyl (meth) acrylate, and more preferably methyl (meth) acrylate.

  Examples of the epoxy (meth) acrylate include glycidyl (meth) acrylate and methyl glycidyl (meth) acrylate. Here, the epoxy (meth) acrylate is a polymer obtained by graft polymerization of components other than epoxy (meth) acrylate, such as urethane (meth) acrylate, and epoxy (meth) acrylate and other monomers are copolymerized. A copolymer comprising However, the content of components other than the epoxy (meth) acrylate in the copolymer is preferably 50% by mass or less.

  The second layer preferably contains a polycarbonate resin, and preferred polycarbonate resins are as described above.

  When the resin layer has the first layer and the second layer, such a layer structure may be formed by applying the other layer to any one layer, or the first layer and the second layer may be formed. The layer structure may be formed by co-extruding the constituent resin. For example, when the first layer includes an alkyl (meth) acrylate resin, the resin layer is preferably formed by coextrusion. Specifically, the resin layer can be formed by co-extrusion of an alkyl (meth) acrylate resin and a polycarbonate resin. That is, the resin layer may be a coextruded film.

In addition, when the first layer contains an epoxy (meth) acrylate resin, a resin composition containing a monomer or a polymer component constituting the first layer is applied on at least one surface of the second layer. A layer may be formed. For example, a bar coater, a roll coater, a gravure coater, a die coater, a curtain coater, an air doctor coater or the like is used as a coating machine that coats the monomer constituting the first layer or a resin composition containing a polymer component. be able to. A bar coater, a die coater, a curtain coater, and a spray coater are preferable because the thickness can be made more uniform.
It is preferable to provide a curing step after coating. As a hardening process, a heating process, a light irradiation process, etc. can be mentioned, for example. In the present invention, it is preferable to provide an ultraviolet irradiation step after using a polycarbonate film as the second layer and coating the epoxy (meth) acrylate resin composition on the film.

  Surface treatment may be applied to the fiber layer side surface of the resin layer. Further, one surface of the second layer, that is, the surface on the first layer side may be subjected to surface treatment. Examples of the surface treatment method include corona treatment, plasma discharge treatment, UV irradiation treatment, electron beam irradiation treatment, and flame treatment. Among these, the surface treatment is preferably at least one selected from corona treatment and plasma discharge treatment. The plasma discharge treatment is preferably a vacuum plasma discharge treatment.

The surface on the fiber layer side of the resin layer may form a fine uneven structure. Further, one surface of the second layer, that is, the surface on the first layer side may be subjected to surface treatment. When the surface has a fine concavo-convex structure, the adhesion between the fiber layer and the resin layer or the adhesion between the first layer and the second layer can be more effectively enhanced. When the fiber layer side surface of the resin layer has a fine concavo-convex structure, such a structure is formed by processing steps such as blast processing, emboss processing, etching processing, corona processing, plasma discharge processing, etc. Is preferred.
In the present specification, the fine concavo-convex structure refers to a structure in which the number of concave portions present on a single straight line having a length of 1 mm drawn at an arbitrary location is 10 or more. When measuring the number of recesses, after immersing the laminate in ion-exchanged water for 24 hours, the fiber layer is peeled off from the resin layer, and then the fiber layer side surface of the resin layer is contacted with a stylus type surface roughness meter ( Measurements can be made by scanning with the Kosaka Laboratory, Surfcoder series). When the uneven pitch is submicron and extremely small on the nano order, the number of uneven portions can be measured from an observation image of a scanning probe microscope (manufactured by Hitachi High-Tech Science Co., Ltd., AFM5000II and AFM5100N).

  The resin layer may contain an optional component other than the synthetic resin. As an arbitrary component, the well-known component used in the resin film field | areas, such as a filler, a pigment, dye, and an ultraviolet absorber, is mentioned, for example.

(Adhesive layer)
The laminate of the present invention includes an adhesive layer. The adhesive layer includes a urethane (meth) acrylate resin. The urethane (meth) acrylate resin is a (meth) acrylate resin having a urethane bond.

The urethane (meth) acrylate resin contains a urethane unit and an acrylic unit. Here, the urethane unit is a unit represented by the following structural formula. In the following structural formula, R ¹ is a linking group containing two or more isocyanate structures or a structure derived from an isocyanate structure, and R ² is a linking group containing two or more hydroxyl groups or a group derived from a hydroxyl group. It is.

The acrylic unit is a unit represented by the following structural formula. In the structural formula below, R ¹ represents a hydrogen atom or a methyl group.

  In the urethane (meth) acrylate resin, when the content (mass%) of the urethane unit is P and the content (mass%) of the acrylic unit is Q, P / Q is 0.1 or more and 0.9 or less. It is preferable. P / Q is more preferably 0.8 or less, and further preferably 0.7 or less. By using a urethane (meth) acrylate resin containing a urethane unit and an acrylic unit in the above ratio, the adhesion between the resin layer and the fiber layer can be more effectively enhanced.

  Further, when the resin layer has a first layer and a second layer, and the first layer contains an alkyl (meth) acrylate resin, P / Q is preferably 0.6 or less. More preferably, it is 5 or less. By using a urethane (meth) acrylate resin containing a urethane unit and an acrylic unit in the above ratio, the adhesion between the resin layer and the fiber layer can be more effectively enhanced.

  Here, content (mass%) of a urethane unit can be measured by the analysis by a nuclear magnetic resonance apparatus, an infrared spectroscopy analyzer, or a trace nitrogen analyzer. The acrylic unit content (% by mass) can be measured by a nuclear magnetic resonance apparatus or an infrared spectroscopic analyzer.

  The glass transition temperature of the urethane (meth) acrylate resin contained in the adhesive layer is preferably 50 ° C. or higher, more preferably 60 ° C. or higher, and further preferably 70 ° C. or higher. Moreover, it is preferable that the glass transition temperature of urethane (meth) acrylate resin is 200 degrees C or less. By setting the glass transition temperature of the urethane (meth) acrylate resin within the above range, the adhesion between the resin layer and the fiber layer can be more effectively increased.

(Fiber layer)
The fiber layer contains fibrous cellulose having a fiber width of 1000 nm or less. The content of fine fibrous cellulose contained in the fiber layer is preferably 60% by mass or more, more preferably 70% by mass or more, and 80% by mass or more with respect to the total mass of the fiber layer. More preferably.

The density of the fiber layer is preferably 1.0 g / cm ³ or more, more preferably 1.2 g / cm ³ or more, and further preferably 1.4 g / cm ³ or more. The density of the fiber layer is preferably 1.7 g / cm ³ or less, more preferably 1.65 g / cm ³ or less, further preferably 1.6 g / cm ³ or less. When the laminated body contains two or more fiber layers, the density of each fiber layer is preferably within the above range.

  The density of the fiber layer is calculated according to JIS P 8118 from the basis weight and thickness of the fiber layer. The basis weight of the fiber layer can be calculated according to JIS P 8124 by cutting so that only the fiber layer of the laminate remains with an ultramicrotome UC-7 (manufactured by JEOL). In addition, when a fiber layer contains arbitrary components other than a fine fibrous cellulose, the density of a fiber layer is a density containing arbitrary components other than a fine fibrous cellulose.

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

<Fine fibrous cellulose>
Although it does not specifically limit as a fibrous cellulose raw material for obtaining a fine fibrous cellulose, It is preferable to use a pulp from the point of being easy to acquire and cheap. Examples of the pulp include wood pulp, non-wood pulp, and deinked pulp. Examples of wood pulp include hardwood kraft pulp (LBKP), softwood kraft pulp (NBKP), sulfite pulp (SP), dissolved pulp (DP), soda pulp (AP), unbleached kraft pulp (UKP), oxygen bleached craft Chemical pulps such as pulp (OKP) are listed. Moreover, semi-chemical pulps such as semi-chemical pulp (SCP) and chemi-ground wood pulp (CGP), mechanical pulps such as ground wood pulp (GP) and thermomechanical pulp (TMP, BCTMP), and the like are exemplified, but not particularly limited. . Non-wood pulp includes cotton pulp such as cotton linter and cotton lint, non-wood pulp such as hemp, straw, and bagasse, cellulose isolated from sea squirts and seaweed, chitin, chitosan, etc., but is not particularly limited. . The deinking pulp includes deinking pulp made from waste paper, but is not particularly limited. The pulp of this embodiment may be used alone or in combination of two or more. Among the above pulps, wood pulp containing cellulose and deinked pulp are preferable in terms of availability. Among wood pulps, chemical pulp has a large cellulose ratio, so the yield of fine fibrous cellulose during fiber refinement (defibration) is high, and the degradation of cellulose in the pulp is small, and the fineness of long fibers with a large axial ratio is high. It is preferable at the point from which fibrous cellulose is obtained. Of these, kraft pulp and sulfite pulp are most preferably selected. A fiber layer containing fine fibrous cellulose of long fibers having a large axial ratio tends to provide high strength.

  The average fiber width of the fine fibrous cellulose is 1000 nm or less as observed with an electron microscope. The average fiber width is preferably 2 nm or more and 1000 nm or less, more preferably 2 nm or more and 100 nm or less, more preferably 2 nm or more and 50 nm or less, and further preferably 2 nm or more and 10 nm or less, but is not particularly limited. When the average fiber width of the fine fibrous cellulose is less than 2 nm, the physical properties (strength, rigidity, dimensional stability) as the fine fibrous cellulose tend to be difficult to be expressed because the cellulose molecules are dissolved in water. . The fine fibrous cellulose is monofilamentous cellulose having a fiber width of 1000 nm or less, for example.

  Measurement of the fiber width of the fine fibrous cellulose by electron microscope observation is performed as follows. An aqueous suspension of fine fibrous cellulose having a concentration of 0.05% by mass or more and 0.1% by mass or less is prepared, and the suspension is cast on a carbon film-coated grid subjected to a hydrophilic treatment to prepare a sample for TEM observation. To do. When a wide fiber is included, an SEM image of the surface cast on glass may be observed. Observation with an electron microscope image is performed at a magnification of 1000 times, 5000 times, 10000 times, or 50000 times depending on the width of the constituent fibers. However, the sample, observation conditions, and magnification are adjusted to satisfy the following conditions.

(1) One straight line X is drawn at an arbitrary location in the observation image, and 20 or more fibers intersect the straight line X.
(2) A straight line Y perpendicular to the straight line is drawn in the same image, and 20 or more fibers intersect the straight line Y.

  The width of the fiber that intersects with the straight line X and the straight line Y is visually read from the observation image that satisfies the above conditions. In this way, at least three sets of images of the surface portion that do not overlap each other are observed, and the width of the fiber intersecting with the straight line X and the straight line Y is read for each image. Thus, at least 20 × 2 × 3 = 120 fiber widths are read. The average fiber width (sometimes simply referred to as “fiber width”) of fine fibrous cellulose is an average value of the fiber widths read in this way.

  The fiber length of the fine 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 particularly preferably 0.1 μm or more and 600 μm or less. By making the fiber length within the above range, the destruction of the crystalline region of the fine fibrous cellulose can be suppressed, and the slurry viscosity of the fine fibrous cellulose can be made an appropriate range. Note that the fiber length of the fine fibrous cellulose can be determined by image analysis using TEM, SEM, or AFM.

The fine fibrous cellulose preferably has an I-type crystal structure. Here, the fact that the fine fibrous cellulose has a type I crystal structure can be identified in a diffraction profile obtained from a wide-angle X-ray diffraction photograph using CuKα (λ = 1.5418Å) monochromatized with graphite. Specifically, it can be identified by having typical peaks at two positions of 2θ = 14 ° to 17 ° and 2θ = 22 ° to 23 °.
The proportion of the I-type crystal structure in the fine fibrous cellulose is preferably 30% or more, more preferably 50% or more, and further preferably 70% or more.

  The ratio of the crystal part contained in the fine fibrous cellulose is not particularly limited in the present invention, but it is preferable to use cellulose having a crystallinity obtained by an X-ray diffraction method of 60% or more. The degree of crystallinity is preferably 65% or more, more preferably 70% or more. In this case, further excellent performance can be expected in terms of heat resistance and low linear thermal expansion. The degree of crystallinity is obtained by measuring an X-ray diffraction profile and determining the crystallinity by a conventional method (Seagal et al., Textile Research Journal, 29, 786, 1959).

  The fine fibrous cellulose is preferably one having a substituent, and the substituent is preferably an anionic group. Examples of the anionic group include a phosphate group or a substituent derived from a phosphate group (sometimes simply referred to as a phosphate group), a carboxyl group or a substituent derived from a carboxyl group (sometimes simply referred to as a carboxyl group), And at least one selected from a sulfone group or a substituent derived from a sulfone group (sometimes simply referred to as a sulfone group), and at least one selected from a phosphate group and a carboxyl group It is more preferable that it is a phosphate group.

The fine fibrous cellulose is preferably one having a phosphate group or a substituent derived from a phosphate group. The phosphoric acid group is a divalent functional group equivalent to the phosphoric acid obtained by removing the hydroxyl group. Specifically, it is a group represented by —PO ₃ H ₂ . Substituents derived from phosphoric acid groups include substituents such as groups obtained by polycondensation of phosphoric acid groups, salts of phosphoric acid groups, and phosphoric acid ester groups. It may be a group.

In the present invention, the phosphate group or the substituent derived from the phosphate group may be a substituent represented by the following formula (1).

In formula (1), a, b, m and n each independently represent an integer (where a = b × m); α ⁿ (n = 1 to n) and α ′ are each independently R or OR is represented. R represents a hydrogen atom, a saturated-linear hydrocarbon group, a saturated-branched hydrocarbon group, a saturated-cyclic hydrocarbon group, an unsaturated-linear hydrocarbon group, an unsaturated-branched hydrocarbon group. , An aromatic group, or a derivative group thereof; β is a monovalent or higher cation composed of an organic substance or an inorganic substance.

<Phosphate group introduction process>
In the phosphate group introduction step, the fiber raw material containing cellulose is reacted with at least one selected from a compound having a phosphate group and a salt thereof (hereinafter referred to as “phosphorylation reagent” or “compound A”). Can be performed. Such a phosphorylating reagent may be mixed in a powder or aqueous solution with a dry or wet fiber raw material. As another example, a phosphorylating reagent powder or an aqueous solution may be added to the fiber raw material slurry.

  The phosphoric acid group introduction step can be performed by reacting at least one selected from a compound having a phosphoric acid group and a salt thereof (a phosphorylating reagent or compound A) with a fiber raw material containing cellulose. This reaction may be carried out in the presence of at least one selected from urea and derivatives thereof (hereinafter referred to as “compound B”).

  As an example of a method for causing compound A to act on a fiber raw material in the presence of compound B, a method of mixing powder or an aqueous solution of compound A and compound B with a dry or wet fiber raw material can be mentioned. Another example is a method in which powders and aqueous solutions of Compound A and Compound B are added to the fiber raw material slurry. Among these, since the uniformity of the reaction is high, a method of adding an aqueous solution of Compound A and Compound B to a dry fiber material, or a powder or an aqueous solution of Compound A and Compound B to a wet fiber material The method is preferred. Moreover, the compound A and the compound B may be added simultaneously, or may be added separately. Moreover, you may add the compound A and the compound B first used for reaction as aqueous solution, and remove an excess chemical | medical solution by pressing. The form of the fiber raw material is preferably cotton or thin sheet, but is not particularly limited.

Compound A used in this embodiment is at least one selected from a compound having a phosphate group and a salt thereof.
Examples of the compound having a phosphate group include, but are not limited to, phosphoric acid, lithium salt of phosphoric acid, sodium salt of phosphoric acid, potassium salt of phosphoric acid, ammonium salt of phosphoric acid, and the like. Examples of the lithium salt of phosphoric acid include lithium dihydrogen phosphate, dilithium hydrogen phosphate, trilithium phosphate, lithium pyrophosphate, and lithium polyphosphate. Examples of the sodium salt of phosphoric acid include sodium dihydrogen phosphate, disodium hydrogen phosphate, trisodium phosphate, sodium pyrophosphate, and sodium polyphosphate. Examples of the potassium salt of phosphoric acid include potassium dihydrogen phosphate, dipotassium hydrogen phosphate, tripotassium phosphate, potassium pyrophosphate, and potassium polyphosphate. Examples of the ammonium salt of phosphoric acid include ammonium dihydrogen phosphate, diammonium hydrogen phosphate, triammonium phosphate, ammonium pyrophosphate, and ammonium polyphosphate.

  Among these, phosphoric acid and phosphoric acid are introduced efficiently from the viewpoint that the introduction efficiency of phosphate groups is high, the fibrillation efficiency is easily improved in the fibrillation process described later, the cost is low, and the industrial application is easy. Sodium salt, potassium salt of phosphoric acid, and ammonium salt of phosphoric acid are preferable. Sodium dihydrogen phosphate or disodium hydrogen phosphate is more preferable.

  In addition, compound A is preferably used as an aqueous solution because the uniformity of the reaction is increased and the efficiency of introduction of phosphate groups is increased. The pH of the aqueous solution of Compound A is not particularly limited, but is preferably 7 or less because the efficiency of introduction of phosphate groups is increased, and more preferably pH 3 or more and pH 7 or less from the viewpoint of suppressing the hydrolysis of pulp fibers. The pH of the aqueous solution of Compound A may be adjusted by, for example, using a phosphoric acid group-containing compound that exhibits acidity and an alkalinity, and changing the amount ratio thereof. You may adjust pH of the aqueous solution of the compound A by adding an inorganic alkali or an organic alkali to the thing which shows acidity among the compounds which have a phosphoric acid group.

  The amount of compound A added to the fiber raw material is not particularly limited, but when the amount of compound A added is converted to phosphorus atomic weight, the amount of phosphorus atom added to the fiber raw material (absolute dry mass) is 0.5 mass% to 100 mass%. Or less, more preferably 1% by mass or more and 50% by mass or less, and most preferably 2% by mass or more and 30% by mass or less. If the amount of phosphorus atoms added to the fiber raw material is within the above range, the yield of fine fibrous cellulose can be further improved. When the addition amount of phosphorus atoms with respect to the fiber raw material exceeds 100% by mass, the effect of improving the yield reaches a peak and the cost of the compound A to be used increases. On the other hand, a yield can be raised by making the addition amount of the phosphorus atom with respect to a fiber raw material more than the said lower limit.

  Examples of the compound B used in this embodiment include urea, biuret, 1-phenylurea, 1-benzylurea, 1-methylurea, 1-ethylurea and the like.

  Compound B is preferably used as an aqueous solution in the same manner as Compound A. Moreover, since the uniformity of reaction increases, it is preferable to use the 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 preferably 1% by mass or more and 500% by mass or less, more preferably 10% by mass or more and 400% by mass or less, and 100% by mass or more and 350% by mass or less. More preferably, it is more preferably 150% by mass or more and 300% by mass or less.

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

  In the phosphoric acid group introduction step, it is preferable to perform a heat treatment. As the heat treatment temperature, it is preferable to select a temperature at which a phosphate group can be efficiently introduced while suppressing thermal decomposition and hydrolysis reaction of the fiber. Specifically, it is 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. Moreover, you may use a vacuum dryer, an infrared heating apparatus, and a microwave heating apparatus for a heating.

  During the heat treatment, while water is contained in the fiber raw material slurry to which compound A is added, if the time for allowing the fiber raw material to stand still becomes long, the compound A dissolved with water molecules moves to the fiber raw material surface with drying. To do. Therefore, the concentration of the compound A in the fiber raw material may be uneven, and the introduction of phosphate groups on the fiber surface may not proceed uniformly. In order to suppress the occurrence of unevenness in concentration of Compound A in the fiber material due to drying, a very thin sheet-like fiber material is used, or the fiber material and Compound A are kneaded or stirred with a kneader or the like and dried by heating or reduced pressure. The method should be taken.

  The heating device used for the heat treatment is preferably a device that can always discharge the moisture retained by the slurry and the moisture generated by the addition reaction of the fibers such as phosphate groups to the hydroxyl group of the fiber, such as a blower oven. Etc. are preferred. If water in the system is always discharged, the hydrolysis reaction of the phosphate ester bond, which is the reverse reaction of the esterification, can be suppressed, and the acid hydrolysis of the sugar chain in the fiber can also be suppressed. A fine fiber having a high axial ratio can be obtained.

  The heat treatment time is also affected by the heating temperature, but it is preferably 1 second or more and 300 minutes or less, preferably 1 second or more and 1000 seconds or less after moisture is substantially removed from the fiber raw material slurry. Preferably, it is 10 seconds or more and 800 seconds or less. In the present invention, by introducing the heating temperature and the heating time within an appropriate range, the amount of phosphate groups introduced can be within a preferable range.

  The amount of phosphate group introduced is preferably 0.1 mmol / g or more and 3.5 mmol / g or less, more preferably 0.14 mmol / g or more and 2.5 mmol / g or less per 1 g (mass) of fine fibrous cellulose. 0.2 mmol / g or more and 2.0 mmol / g or less is more preferable, 0.2 mmol / g or more and 1.8 mmol / g or less is more preferable, 0.4 mmol / g or more and 1.8 mmol / g or less is particularly preferable, Preferably they are 0.6 mmol / g or more and 1.8 mmol / g or less. By making the introduction amount of the phosphoric acid group within the above range, the fiber raw material can be easily refined, and the stability of the fine fibrous cellulose can be enhanced. Moreover, the viscosity of the slurry of a fine fibrous cellulose can be adjusted to an appropriate range by making the introduction amount of phosphoric acid groups within the above range.

  The amount of phosphate group introduced into the fiber material can be measured by a conductivity titration method. Specifically, by performing the defibration process step, after treating the resulting fine fibrous cellulose-containing slurry with an ion exchange resin, by determining the change in electrical conductivity while adding an aqueous sodium hydroxide solution, The amount introduced can be measured.

  In conductivity titration, the curve shown in FIG. 4 is given when alkali is added. Initially, the electrical conductivity rapidly decreases (hereinafter referred to as “first region”). Thereafter, the conductivity starts to increase slightly (hereinafter referred to as “second region”). Thereafter, the conductivity increment increases (hereinafter referred to as “third region”). That is, three areas appear. Among these, the amount of alkali required in the first region is equal to the amount of strongly acidic groups in the slurry used for titration, and the amount of alkali required in the second region is the amount of weakly acidic groups in the slurry used for titration. Will be equal. When the phosphoric acid group undergoes condensation, apparently weakly acidic groups are lost, and the amount of alkali required in the second region is reduced compared to the amount of alkali required in the first region. On the other hand, the amount of strongly acidic groups coincides with the amount of phosphorus atoms regardless of the presence or absence of condensation, so that the amount of phosphate groups introduced (or the amount of phosphate groups) or the amount of substituent introduced (or the amount of substituents) is simply When said, it represents the amount of strongly acidic group. That is, the alkali amount (mmol) required in the first region of the curve shown in FIG. 4 is divided by the solid content (g) in the titration target slurry to obtain the substituent introduction amount (mmol / g).

  The phosphate group introduction step may be performed at least once, but may be repeated a plurality of times. In this case, more phosphoric acid groups are introduced, which is preferable.

<Alkali treatment>
When manufacturing a fine fibrous cellulose, you may perform an alkali treatment between a phosphate group introduction | transduction process and the defibration process mentioned later. Although it does not specifically limit as a method of an alkali treatment, For example, the method of immersing a phosphate group introduction | transduction fiber in an alkaline solution is mentioned.
The alkali compound contained in the alkali solution is not particularly limited, but may be an inorganic alkali compound or an organic alkali compound. The solvent in the alkaline solution may be either water or an organic solvent. The solvent is preferably a polar solvent (polar organic solvent such as water or alcohol), and more preferably an aqueous solvent containing at least water.
Of the alkaline solutions, a sodium hydroxide aqueous solution or a potassium hydroxide aqueous solution is particularly preferred because of its high versatility.

Although the temperature of the alkali solution in an alkali treatment process is not specifically limited, 5 to 80 degreeC is preferable and 10 to 60 degreeC is more preferable.
The immersion time in the alkaline solution in the alkali treatment step is not particularly limited, but is preferably 5 minutes or longer and 30 minutes or shorter, and more preferably 10 minutes or longer and 20 minutes or shorter.
Although the usage-amount of the alkaline solution in an alkali treatment is not specifically limited, It is preferable that it is 100 mass% or more and 100,000 mass% or less with respect to the absolute dry mass of a phosphate group introduction | transduction fiber, and is 1000 mass% or more and 10000 mass% or less. It is more preferable.

  In order to reduce the amount of alkaline solution used in the alkali treatment step, the phosphate group-introduced fiber may be washed with water or an organic solvent before the alkali treatment step. After the alkali treatment, in order to improve the handleability, it is preferable to wash the alkali-treated phosphate group-introduced fiber with water or an organic solvent before the defibrating treatment step.

<Defibration processing>
The phosphate group-introduced fiber is defibrated in the defibrating process. In the defibrating process, the fiber is usually defibrated using a defibrating apparatus to obtain a fine fibrous cellulose-containing slurry, but the processing apparatus and the processing method are not particularly limited.
As the defibrating apparatus, a high-speed defibrator, a grinder (stone mill type pulverizer), a high-pressure homogenizer, an ultra-high pressure homogenizer, a high-pressure collision type pulverizer, a ball mill, a bead mill, or the like can be used. Alternatively, as a defibrating apparatus, a wet type pulverizer such as a disk refiner, a conical refiner, a twin-screw kneader, a vibration mill, a homomixer under high-speed rotation, an ultrasonic disperser, or a beater should be used. You can also. The defibrating apparatus is not limited to the above. Preferable defibrating treatment methods include a high-speed defibrator, a high-pressure homogenizer, and an ultra-high pressure homogenizer that are less affected by the grinding media and less worried about contamination.

  In the defibrating process, it is preferable to dilute the fiber raw material with water and an organic solvent alone or in combination to form a slurry, but there is no particular limitation. As the dispersion medium, in addition to water, a polar organic solvent can be used. Preferable polar organic solvents include alcohols, ketones, ethers, dimethyl sulfoxide (DMSO), dimethylformamide (DMF), dimethylacetamide (DMAc), and the like, but are not particularly limited. Examples of alcohols include methanol, ethanol, n-propanol, isopropanol, n-butanol, and t-butyl alcohol. Examples of ketones include acetone and methyl ethyl ketone (MEK). Examples of ethers include diethyl ether and tetrahydrofuran (THF). The dispersion medium may be one type or two or more types. Further, the dispersion medium may contain a solid content other than the fiber raw material, such as urea having hydrogen bonding property.

  In the present invention, the fibrillation treatment may be performed after the fine fibrous cellulose is concentrated and dried. In this case, the concentration and drying methods are not particularly limited, and examples thereof include a method of adding a concentrating agent to a slurry containing fine fibrous cellulose, a generally used dehydrator, a press, and a method using a dryer. Moreover, a well-known method, for example, the method described in WO2014 / 024876, WO2012 / 107642, and WO2013 / 121086 can be used. Further, the concentrated fine fibrous cellulose may be formed into a sheet. The sheet can be pulverized to perform a defibrating process.

  The equipment used for pulverization of fine fibrous cellulose includes high-speed defibrator, grinder (stone mill type pulverizer), high-pressure homogenizer, ultra-high pressure homogenizer, high-pressure collision type pulverizer, ball mill, bead mill, disk type refiner, conical An apparatus for wet pulverization such as a refiner, a twin-screw kneader, a vibration mill, a homomixer under high-speed rotation, an ultrasonic disperser, a beater, and the like can be used, but is not particularly limited.

  The fine fibrous cellulose-containing product having a phosphoric acid group obtained by the above-described method is a fine fibrous cellulose-containing slurry, and may be diluted with water so as to have a desired concentration.

<Optional component>
The fiber layer may contain an optional component other than the fine fibrous cellulose. Examples of optional components include hydrophilic polymers and organic ions. The hydrophilic polymer is preferably a hydrophilic oxygen-containing organic compound (however, excluding the cellulose fiber). The oxygen-containing organic compound is preferably non-fibrous, and such non-fibrous oxygen-containing organic compound does not contain fine fibrous cellulose or thermoplastic resin fibers.

  The oxygen-containing organic compound is preferably a hydrophilic organic compound. The hydrophilic oxygen-containing organic compound can improve the strength, density and chemical resistance of the fiber layer. The hydrophilic oxygen-containing organic compound preferably has, for example, an SP value of 9.0 or more. The hydrophilic oxygen-containing organic compound is preferably one in which 1 g or more of the oxygen-containing organic compound is dissolved in, for example, 100 ml of ion exchange water.

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

  The oxygen-containing organic compound is preferably an organic compound polymer having a molecular weight of 50,000 to 8,000,000. The molecular weight of the oxygen-containing organic compound is preferably 100,000 to 5,000,000, but may be a low molecule having a molecular weight of less than 1,000, for example.

  The content of the oxygen-containing organic compound contained in the fiber layer is preferably 1 part by mass or more and 40 parts by mass or less, with respect to 100 parts by mass of the fine fibrous cellulose contained in the fiber layer. More preferably, the amount is 15 parts by mass or more and 25 parts by mass or less. By setting the content of the oxygen-containing organic compound within the above range, a laminate having high transparency and strength can be formed.

  Examples of organic ions include tetraalkylammonium ions and tetraalkylphosphonium ions. Examples of tetraalkylammonium ions include tetramethylammonium ion, tetraethylammonium ion, tetrapropylammonium ion, tetrabutylammonium ion, tetrapentylammonium ion, tetrahexylammonium ion, tetraheptylammonium ion, tributylmethylammonium ion, and lauryltrimethyl. Examples include ammonium ion, cetyltrimethylammonium ion, stearyltrimethylammonium ion, octyldimethylethylammonium ion, lauryldimethylethylammonium ion, didecyldimethylammonium ion, lauryldimethylbenzylammonium ion, and tributylbenzylammonium ion. Examples of tetraalkylphosphonium ions include tetramethylphosphonium ions, tetraethylphosphonium ions, tetrapropylphosphonium ions, tetrabutylphosphonium ions, and lauryltrimethylphosphonium ions. In addition, examples of the tetrapropylonium ion and the tetrabutylonium ion include a tetra n-propylonium ion and a tetra n-butylonium ion, respectively.

(Laminate manufacturing method)
The present invention provides a process for obtaining a fiber layer containing fibrous cellulose having a fiber width of 1000 nm or less, and a resin composition containing urethane (meth) acrylate is applied on at least one surface of the fiber layer to form an adhesive layer And a step of laminating a resin layer on the surface opposite to the fiber layer on one surface of the adhesive layer.

<Step of obtaining fiber layer>
The step of obtaining a fiber layer (hereinafter also referred to as a fine fibrous cellulose-containing sheet) is a step of coating a fine fibrous cellulose dispersion (fine fibrous cellulose-containing slurry) on a substrate or a fine fibrous cellulose dispersion. It is preferable to include a step of papermaking. Especially, it is preferable that the manufacturing process of a fine fibrous cellulose containing sheet | seat includes the process of coating a fine fibrous cellulose dispersion liquid on a base material.

<Coating process>
A coating process is a process of obtaining a sheet | seat by peeling the fine fibrous cellulose containing sheet | seat formed by apply | coating a fine fibrous cellulose dispersion liquid on a base material, and drying this. By using a coating apparatus and a long base material, sheets can be continuously produced. Although the density | concentration of the fine fibrous cellulose dispersion liquid to apply is not specifically limited, 0.05 mass% or more and 5 mass% or less are preferable.

  The fine fibrous cellulose dispersion preferably contains an oxygen-containing organic compound. The content of the oxygen-containing organic compound is preferably 1 part by mass or more and 40 parts by mass or less, and preferably 10 parts by mass or more and 30 parts by mass with respect to 100 parts by mass of the fine fibrous cellulose contained in the fine fibrous cellulose dispersion. It is more preferable that the amount is 15 parts by mass or more and 25 parts by mass or less.

  The quality of the base material used in the coating process is not particularly limited, but the one having higher wettability with respect to the fine fibrous cellulose dispersion may be able to suppress sheet shrinkage during drying, but is formed after drying. It is preferable to select a sheet that can be easily peeled off. Among them, a resin plate or a metal plate is preferable, but is not particularly limited. For example, resin plates such as acrylic plates, polyethylene terephthalate plates, vinyl chloride plates, polystyrene plates, polyvinylidene chloride plates, metal plates such as aluminum plates, zinc plates, copper plates, iron plates, etc., and those whose surfaces are oxidized, stainless steel A plate, a brass plate or the like can be used.

  In the coating process, when the fine fibrous cellulose dispersion is low in viscosity and spreads on the base material, it is used for blocking on the base material in order to obtain a fine fibrous cellulose-containing sheet with a predetermined thickness and basis weight. The frame may be fixed and used. The quality of the damming frame is not particularly limited, but it is preferable to select one that can easily peel off the edge of the sheet attached after drying. Among them, a molded resin plate or metal plate is preferable, but is not particularly limited. For example, resin plates such as acrylic plates, polyethylene terephthalate plates, vinyl chloride plates, polystyrene plates, polyvinylidene chloride plates, metal plates such as aluminum plates, zinc plates, copper plates, iron plates, etc., and those whose surfaces are oxidized, stainless steel A molded plate, brass plate, or the like can be used.

  As a coating machine for coating the fine fibrous cellulose dispersion, for example, a bar coater, a roll coater, a gravure coater, a die coater, a curtain coater, an air doctor coater or the like can be used. A bar coater, a die coater, a curtain coater, and a spray coater are preferable because the thickness can be made more uniform.

  The coating temperature is not particularly limited, but is preferably 20 ° C. or higher and 45 ° C. or lower. If the coating temperature is equal to or higher than the above lower limit value, the fine fibrous cellulose dispersion can be easily applied. If the coating temperature is equal to or lower than the upper limit value, volatilization of the dispersion medium during coating can be suppressed.

In the coating step, it is preferable to apply the fine fibrous cellulose dispersion so that the finished basis weight of the sheet is 10 g / m ² or more and 100 g / m ² or less. By coating so that the basis weight falls within the above range, a fiber layer having excellent strength can be obtained.

  The production process of the fine fibrous cellulose-containing sheet preferably includes a step of drying the fine fibrous cellulose dispersion coated on the substrate. Although it does not specifically limit as a drying method, Either a non-contact drying method or the method of drying while restraining a sheet | seat may be sufficient, and these may be combined.

  The non-contact drying method is not particularly limited, but a method of drying by heating with hot air, infrared rays, far infrared rays or near infrared rays (heating drying method) or a method of drying in vacuum (vacuum drying method) is applied. Can do. Although the heat drying method and the vacuum drying method may be combined, the heat drying method is usually applied. Although drying by infrared rays, far infrared rays, or near infrared rays can be performed using an infrared device, a far infrared device, or a near infrared device, it is not particularly limited. The heating temperature in the heat drying method is not particularly limited, but is preferably 20 ° C. or higher and 150 ° C. or lower, and more preferably 25 ° C. or higher and 105 ° C. or lower. If the heating temperature is not less than the above lower limit value, the dispersion medium can be volatilized quickly, and if it is not more than the above upper limit value, it is possible to suppress the cost required for heating and to prevent the fine fibrous cellulose from being discolored by heat. .

  After drying, the obtained fine fibrous cellulose-containing sheet is peeled off from the base material, but when the base material is a sheet, the fine fibrous cellulose-containing sheet and the base material are wound while being laminated to form a fine fibrous form. The fine fibrous cellulose-containing sheet may be peeled from the process substrate immediately before use of the cellulose-containing sheet.

<Paper making process>
The production process of the fine fibrous cellulose-containing sheet may include a step of paper making the fine fibrous cellulose dispersion. Examples of the paper machine in the paper making process include a continuous paper machine such as a long-mesh type, a circular net type, and an inclined type, and a multi-layered paper machine combining these. In the paper making process, known paper making such as hand making may be performed.

In the paper making process, the fine fibrous cellulose dispersion is filtered and dehydrated on a wire to obtain a wet paper sheet, and then the sheet is obtained by pressing and drying. Although the density | concentration of a fine fibrous cellulose dispersion liquid is not specifically limited, 0.05 mass% or more and 5 mass% or less are preferable. Moreover, it is preferable that the fine fibrous cellulose dispersion contains an oxygen-containing organic compound. The content of the oxygen-containing organic compound is as described above.

  When the fine fibrous cellulose dispersion is filtered and dehydrated, the filter cloth at the time of filtration is not particularly limited, but it is important that the fine fibrous cellulose does not pass through and the filtration rate is not too slow. Although it does not specifically limit as such a filter cloth, The sheet | seat, fabric, and porous film which consist of organic polymers are preferable. The organic polymer is not particularly limited, but non-cellulosic organic polymers such as polyethylene terephthalate, polyethylene, polypropylene, polytetrafluoroethylene (PTFE) and the like are preferable. Specific examples include a porous film of polytetrafluoroethylene having a pore size of 0.1 μm to 20 μm, for example, 1 μm, polyethylene terephthalate or polyethylene woven fabric having a pore size of 0.1 μm to 20 μm, for example, 1 μm, but is not particularly limited.

  Although it does not specifically limit as a method of manufacturing a sheet | seat from a fine fibrous cellulose dispersion liquid, For example, the method of using the manufacturing apparatus of WO2011 / 013567, etc. are mentioned. This manufacturing apparatus discharges a fine fibrous cellulose dispersion onto the upper surface of an endless belt, and squeezes a dispersion medium from the discharged fine fibrous cellulose dispersion to generate a web, and dries the web. And a drying section for producing a fiber sheet. An endless belt is disposed from the squeezing section to the drying section, and the web generated in the squeezing section is conveyed to the drying section while being placed on the endless belt.

  Although it does not specifically limit as the dehydration method which can be used in this invention, The dehydration method normally used by manufacture of paper is mentioned, After dehydrating with a long net, a circular net, a slanted wire, etc., it dehydrates with a roll press. Is preferred. The drying method is not particularly limited, and examples thereof include methods used in paper production. For example, methods such as a cylinder dryer, a Yankee dryer, hot air drying, a near infrared heater, and an infrared heater are preferable.

<Step of forming an adhesive layer>
In the step of forming the adhesive layer, a resin composition containing urethane (meth) acrylate is applied onto at least one surface of the fiber layer. The resin composition preferably contains at least urethane (meth) acrylate, and further contains a crosslinking agent such as an isocyanate compound. Moreover, since the resin composition performs the polymerization reaction of the acrylic unit of urethane (meth) acrylate, it may contain a polymerization initiator. Furthermore, the resin composition may contain an arbitrary dilution solvent in order to adjust the coatability.

As a coating machine for coating a resin composition containing urethane (meth) acrylate, for example, a bar coater, a roll coater, a gravure coater, a die coater, a curtain coater, an air doctor coater or the like can be used.
It is preferable to provide a step of curing the resin after coating. In the curing step, heating is preferably performed so that the temperature is 20 ° C. or higher and 150 ° C. or lower. The heating time is preferably from 0.1 hour to 10 hours.

<Process of laminating resin layers>
In the step of laminating the resin layer, the resin layer is laminated on one surface of the adhesive layer and on the surface opposite to the fiber layer. That is, in the step of laminating the resin layer, the fiber layer and the resin layer are bonded via the adhesive layer. In the step of laminating the resin layer, it is preferable that the fiber layer and the resin layer are laminated via the adhesive layer, and then sandwiched between the fiber layer side and the resin layer side with a plate-like object such as a metal plate and pressed. It is also preferable to heat at the time of pressing. In this case, the pressing pressure is preferably 0.1 MPa or more, more preferably 0.5 MPa or more, further preferably 1 MPa or more, and may be 3 MPa or more. Further, the press pressure is preferably 20 MPa or less, and more preferably 10 MPa or less. The heating temperature is preferably 20 ° C. or higher and 250 ° C. or lower. The pressing time is preferably 10 seconds or more and 10 minutes or less.

  The manufacturing process of the laminated body of the present invention includes the first layer and the second layer disposed on one side of the first layer and on the side opposite to the adhesive layer before the step of laminating the resin layers. It is preferable to further include a step of forming a resin layer having In this case, the resin layer may be formed by coating the other layer on one of the first layer and the second layer, and the resin constituting the first layer and the second layer is coextruded. May be formed.

When the first layer includes an epoxy (meth) acrylate resin, the step of forming the resin layer preferably includes a step of applying an epoxy (meth) acrylate-containing composition on the second layer. In this case, the second layer preferably includes at least one selected from a polycarbonate resin and an acrylic resin, and more preferably includes a polycarbonate resin. That is, the first layer of the resin layer includes an epoxy (meth) acrylate resin, the second layer includes a polycarbonate resin, and the resin layer is coated with an epoxy (meth) acrylate-containing composition on the second layer. It is preferable that it is formed by doing so.
It is preferable that an epoxy (meth) acrylate containing composition contains an epoxy (meth) acrylate at least. Moreover, since an epoxy (meth) acrylate containing composition performs the polymerization reaction of the acrylic unit of epoxy (meth) acrylate, and the polymerization reaction based on an epoxy group, it may contain a polymerization initiator. Furthermore, the epoxy (meth) acrylate-containing composition may contain an arbitrary dilution solvent in order to adjust the coating property.

When the first layer includes an alkyl (meth) acrylate resin, the step of forming the resin layer is preferably a step of forming the first layer and the second layer by coextrusion. In this case, the second layer preferably includes at least one selected from a polycarbonate resin and an acrylic resin, and more preferably includes a polycarbonate resin. That is, the first layer of the resin layer includes an alkyl (meth) acrylate resin, the second layer includes a polycarbonate resin, and the resin layer is formed by coextrusion of the first layer and the second layer. Is preferred.
In the step of forming by coextrusion, for example, a resin layer can be formed by coextrusion of an alkyl (meth) acrylate resin and a polycarbonate resin.

In the step of forming the resin layer, at least one surface of the resin layer may be subjected to surface treatment, or at least one surface of the second layer in the resin layer may be subjected to surface treatment. As the surface treatment, for example, corona treatment, plasma discharge treatment, UV irradiation treatment, electron beam irradiation treatment, flame treatment or the like can be performed.
Further, the step of forming the resin layer may include a step of forming a fine concavo-convex structure, and may include a step of forming a fine concavo-convex structure on at least one surface of the second layer in the resin layer. Examples of the process for forming the fine concavo-convex structure include a blasting process, an embossing process, an etching process, a corona process, and a plasma discharge process.

  In addition to the method described above, the laminate may be manufactured by placing a laminated sheet having a fiber layer and an adhesive layer in an injection mold so that the adhesive layer is exposed, and then heating the mold. Another example is a method of injecting and joining the molten resin.

(Inorganic film laminate)
The laminate of the present invention may further have an inorganic film (hereinafter also referred to as an inorganic layer). The inorganic layer may be laminated on the fiber layer side or may be laminated on the resin layer side. Moreover, an inorganic layer may be laminated | stacked on both sides of a laminated body.

  The material constituting the inorganic layer is not particularly limited, but for example, aluminum, silicon, magnesium, zinc, tin, nickel, titanium; these oxides, carbides, nitrides, oxycarbides, oxynitrides, or oxycarbonitrides Or a mixture thereof. From the viewpoint that high moisture resistance can be stably maintained, silicon oxide, silicon nitride, silicon oxide carbide, silicon oxynitride, silicon oxycarbonitride, aluminum oxide, aluminum nitride, aluminum oxide carbide, aluminum oxynitride, or these Mixtures are preferred.

  The method for forming the inorganic layer is not particularly limited. In general, a method for forming a thin film is roughly classified into a chemical vapor deposition method (CVD) and a physical film deposition method (Physical Vapor Deposition, PVD), and either method may be adopted. . Specific examples of the CVD method include plasma CVD using plasma and catalytic chemical vapor deposition (Cat-CVD) in which a material gas is contact pyrolyzed using a heating catalyst. Specific examples of the PVD method include vacuum deposition, ion plating, and sputtering.

  As an inorganic layer forming method, an atomic layer deposition (ALD) can be employed. The ALD method is a method of forming a thin film in units of atomic layers by alternately supplying source gases of respective elements constituting a film to be formed to a surface on which a layer is formed. Although there is a drawback that the film forming speed is slow, there is an advantage that it is possible to form a thin film with few defects because it can cleanly cover even a complicated surface more than the plasma CVD method. In addition, the ALD method has an advantage that the film thickness can be controlled on the nano order and it is relatively easy to cover a wide surface. Furthermore, the ALD method can be expected to improve the reaction rate, process at a low temperature, and reduce unreacted gas by using plasma.

  Although the thickness of an inorganic layer is not specifically limited, For example, when aiming at expression of moisture-proof performance, it is preferably 5 nm or more, more preferably 10 nm or more, and further preferably 20 nm or more. From the viewpoint of transparency and flexibility, the thickness of the inorganic layer is preferably 1000 nm or less, more preferably 800 nm or less, and even more preferably 600 nm or less.

(Use)
A preferred embodiment of the laminate of the present invention is a laminate that is transparent and has high mechanical strength and low haze. From the viewpoint of utilizing excellent optical characteristics, it is suitable for applications of light-transmitting substrates such as various display devices and various solar cells. It is also suitable for applications such as substrates for electronic devices, members of household appliances, various vehicles and building windows, interior materials, exterior materials, packaging materials, and the like.

  Hereinafter, the features of the present invention will be described more specifically with reference to Examples and Comparative Examples. The materials, amounts used, ratios, processing details, processing procedures, and the like shown in the following examples can be changed as appropriate without departing from the spirit of the present invention. Therefore, the scope of the present invention should not be construed as being limited by the specific examples shown below.

<Example 1>
[Phosphorylation]
Oji Paper's pulp (solid content: 93%, basis weight: 208 g / m ² sheet, Canadian standard freeness (CSF) 700 ml, measured according to JIS P 8121) was used as the softwood kraft pulp. . 100 parts by mass of the above softwood kraft pulp (absolutely dry mass) is impregnated with a mixed aqueous solution of ammonium dihydrogen phosphate and urea, and compressed to 45 parts by mass of ammonium dihydrogen phosphate and 200 parts by mass of urea, and impregnated with a chemical solution. Pulp was obtained. The obtained chemical solution-impregnated pulp was dried and heat-treated for 200 seconds with a hot air dryer at 165 ° C. to introduce phosphate groups into cellulose in the pulp. The amount of phosphate groups introduced at this time was 0.98 mmol / g.

  The amount of phosphate groups introduced was measured by diluting cellulose with ion-exchanged water so that the content was 0.2% by mass, and then treating with ion-exchange resin and titration with alkali. In the treatment with an ion exchange resin, 1/10 by volume of a strongly acidic ion exchange resin (manufactured by Organo Corporation, Amberjet 1024: conditioned) is added to the 0.2 mass% cellulose-containing slurry, followed by shaking treatment for 1 hour. went. Thereafter, the mixture was poured onto a mesh having an opening of 90 μm to separate the resin and the slurry. In titration using an alkali, a change in the value of electrical conductivity exhibited by the slurry was measured while adding a 0.1 N sodium hydroxide aqueous solution to the fibrous cellulose-containing slurry after ion exchange. That is, the alkali amount (mmol) required in the first region of the curve shown in FIG. 4 was divided by the solid content (g) in the titration target slurry to obtain the substituent introduction amount (mmol / g).

[Alkali treatment and cleaning]
Next, 5000 ml of ion-exchanged water was added to the cellulose into which the phosphate group was introduced, and the mixture was dehydrated after washing with stirring. The pulp after dehydration was diluted with 5000 ml of ion-exchanged water, and while stirring, a 1N sodium hydroxide aqueous solution was added little by little until the pH became 12 or more and 13 or less to obtain a pulp dispersion. Thereafter, this pulp dispersion was dehydrated and washed by adding 5000 ml of ion exchange water. This dehydration washing was repeated once more.

[Machine processing]
Ion exchange water was added to the pulp obtained after washing and dewatering to obtain a pulp dispersion having a solid content of 1.0% by mass. This pulp dispersion liquid was processed using a high-pressure homogenizer (Panda Plus 2000, manufactured by NiroSoavi) to obtain a cellulose dispersion liquid. In the treatment using the high-pressure homogenizer, the homogenizing chamber was passed 5 times at an operating pressure of 1200 bar. Furthermore, this cellulose dispersion was processed using a wet atomization apparatus (manufactured by Sugino Machine Co., Ltd., an optimizer) to obtain a fine fibrous cellulose dispersion (A). In the treatment using the wet atomizer, the treatment chamber was passed five times at a pressure of 245 MPa. The average fiber width of the fine fibrous cellulose contained in the fine fibrous cellulose dispersion (A) was 4 nm.

[Formation of fiber layer]
The concentration was adjusted so that the solid content concentration of the fine fibrous cellulose dispersion (A) was 0.5% by mass. Thereafter, 20 parts by mass of a 0.5% by mass aqueous solution of polyethylene oxide (manufactured by Sumitomo Seika Co., Ltd., PEO-18) is added to 100 parts by mass of the fine fibrous cellulose dispersion (A) to disperse the fine fibrous cellulose. A liquid (B) was obtained. Next, the fine fibrous cellulose dispersion (B) is weighed so that the finished basis weight of the cellulose fiber-containing layer (layer composed of the solid content of the fine fibrous cellulose dispersion (B)) is 50 g / m ^2. Then, it was applied to a commercially available acrylic plate and dried in a constant temperature and humidity chamber at 35 ° C. and a relative humidity of 15%. In addition, a metal frame for damming (a metal frame having an inner dimension of 180 mm × 180 mm) was disposed on the acrylic plate so as to have a predetermined basis weight. By the above procedure, a fiber layer (cellulose fiber-containing layer) was obtained.

[Lamination of adhesive layer]
100 parts by mass of urethane acrylate having a urethane / acrylic ratio of 2/8 (manufactured by Taisei Fine Chemical Co., Ltd., Acryt 8UA-347A) and 9.7 parts by mass of isocyanurate compound (manufactured by Asahi Kasei Chemicals Co., Ltd., Duranate TPA-100) Resin composition A was obtained. Next, on one surface of the fiber layer, the resin composition A was applied with a bar coater and dried with a constant temperature dryer at 100 ° C. for 1 hour. By the above procedure, a laminated sheet A in which an adhesive layer was laminated on one surface of the fiber layer was obtained.

[Formation of resin layer]
39 parts by mass of epoxy urethane acrylate (manufactured by Arakawa Chemical Industries, Ltd., Beam Set 371), 21 parts by mass of methyl ethyl ketone, and 2 parts by mass of a radical polymerization initiator (manufactured by BASF, Irgacure 184) were mixed to obtain a resin composition B. Next, the resin composition B was applied on one surface of a polycarbonate film (Teijin Limited, Panlite PC-2151: thickness 300 μm) with a bar coater, and dried for 3 minutes. Subsequently, the resin composition B was hardened by irradiating 500 mJ / cm < ² > of ultraviolet-rays using UV conveyor apparatus (ECS-4011GX by the eye graphics company). By the above procedure, a resin layer having an epoxy urethane acrylate resin layer was formed on the polycarbonate film.

[Lamination of laminated sheet A and resin layer]
The laminated sheet A and the resin layer were cut into 100 mm squares. Next, the laminated sheet A was laminated so that the surface on which the adhesive layer was laminated and the epoxy urethane acrylate resin layer surface of the resin layer were in contact with each other, and sandwiched between stainless plates having a thickness of 2 mm and dimensions of 200 mm × 200 mm. In addition, as the stainless steel plate, a plate obtained by applying a release agent (manufactured by Odek Co., Ltd., Teflys) to the holding surface was used. Then, it inserted in the mini test press (the Toyo Seiki Kogyo company make, MP-WCH) set to normal temperature, and heated up to 180 degreeC over 3 minutes under the press pressure of 1 MPa. After maintaining in this state for 30 seconds, it was cooled to 30 ° C. over 5 minutes. By the above procedure, a laminate in which the fiber layer was laminated with the resin layer via the adhesive layer was obtained.

<Example 2>
In Example 1, when the laminated sheet A and the resin layer were laminated, the press pressure was changed from 1 MPa to 5 MPa. Other procedures were the same as in Example 1 to obtain a laminate in which the fiber layer was laminated with the resin layer via the adhesive layer.

<Example 3>
When laminating the adhesive layer of Example 1, instead of the urethane acrylate having a urethane / acryl ratio of 2/8, a urethane acrylate having a urethane / acryl ratio of 4/6 (Acrit 8UA-540, manufactured by Taisei Fine Chemical Co., Ltd.) It was used. Other procedures were the same as in Example 1 to obtain a laminate in which the fiber layer was laminated with the resin layer via the adhesive layer.

<Example 4>
In Example 3, when the laminated sheet A and the resin layer were laminated, the press pressure was changed from 1 MPa to 5 MPa. Other procedures were the same as in Example 1 to obtain a laminate in which the fiber layer was laminated with the resin layer via the adhesive layer.

<Example 5>
In Example 2, instead of a resin layer having an epoxy urethane acrylate resin layer on a polycarbonate film, a coextruded film (Iupilon MR-DF02U: thickness 300 μm) formed by coextruding a polycarbonate resin and an acrylic resin is used. did. When the laminated sheet A and the resin layer were laminated, the coextruded film was laminated so that the acrylic resin side surface of the coextruded film was in contact with the adhesive layer side surface of the laminated sheet A. Other procedures were the same as in Example 2 to obtain a laminate in which the fiber layer was laminated with the resin layer via the adhesive layer.

<Comparative Example 1>
In Example 1, the adhesive layer was not laminated. Further, the resin composition B was not applied in the formation of the resin layer. Other procedures were the same as in Example 1, and a laminate in which the fiber layer was laminated with the resin layer without an adhesive layer was obtained.

<Comparative Example 2>
In Example 2, when the adhesive layer was laminated, the composition of the resin composition A was changed to 100 parts by mass of an acrylic resin in which acryloyl groups were graft-polymerized (manufactured by Taisei Fine Chemical Co., Ltd., Acryt 8KX-012C) and an isocyanate compound (Asahi Kasei Chemicals Co., Ltd.). Manufactured by TPA-100) and 2 parts by mass of radical polymerization initiator (BASF, Irgacure 184). Other procedures were the same as in Example 2 to obtain a laminate in which the fiber layer was laminated with the resin layer via the adhesive layer.

<Measurement>
The laminates obtained in Examples and Comparative Examples were evaluated by the following methods.

[Thickness of laminate]
The thickness of the laminated body was measured with a stylus type thickness meter (manufactured by Marl, Millitron 1202D).

[Thickness of fiber layer (cellulose fiber-containing layer)]
Before the lamination, the thickness of the fiber layer was measured with a stylus type thickness meter (Milltron 1202D, manufactured by Marl Co., Ltd.) to obtain the thickness of the fiber layer in the laminate.

[Adhesive layer thickness]
Before the lamination sheet A and the resin layer are laminated, the thickness of the lamination sheet A is measured with a stylus type thickness meter (Milltron 1202D manufactured by Marl), and the thickness of the fiber layer is subtracted from the thickness of the lamination sheet A. Then, the thickness of the adhesive layer in the laminate was calculated.

[Thickness of resin layer]
The thickness of the resin layer in the laminate was calculated by subtracting the thickness of the fiber layer and the thickness of the adhesive layer from the thickness of the laminate.

[Density of fiber layer (cellulose fiber-containing layer)]
The basis weight (50 g / m ² ) of the fiber layer was divided by the thickness of the fiber layer to obtain the density of the fiber layer.

<Evaluation>
The laminates obtained in Examples and Comparative Examples were evaluated by the following methods.

[Adhesion between fiber layer and resin layer]
In accordance with JIS K 5400, 100 1 mm ² crosscuts were put in the fiber layers of the laminates of Examples and Comparative Examples. Next, a cellophane tape (manufactured by Nichiban Co., Ltd.) was applied thereon, pressed with a load of 1.5 kg / cm ² , and then peeled in the 90 ° direction. The adhesion between the fiber layer and the resin layer was evaluated based on the number of the separated cells.

[Adhesion of fiber layer and resin layer when bending stress is applied]
The laminates of Examples and Comparative Examples were broken by bending 180 ° with the fiber layer inside. The fracture behavior of the laminate after fracture was observed and evaluated according to the following evaluation criteria, and used as an index of adhesion when applying a bending stress between the fiber layer and the resin layer.
A: The site where peeling occurs is not observed, and the laminated structure is maintained even after breaking.
○: Although slight peeling is observed at the site where the fracture occurred, the laminated structure is maintained.
X: Peeling occurs and the laminated structure is not maintained.

[Total light transmittance of laminate]
Based on JIS K 7361, the total light transmittance of the laminated body was evaluated using a haze meter (manufactured by Murakami Color Research Laboratory Co., Ltd., HM-150).

[Haze of laminate]
Based on JISK7136, the haze of the laminated body was evaluated using a haze meter (manufactured by Murakami Color Research Laboratory Co., Ltd., HM-150).

  As is apparent from Table 1, in the example in which the urethane acrylate resin layer was formed as the adhesive layer, a laminate having good adhesion between the fiber layer and the resin layer was obtained while maintaining transparency. This adhesion was also good when bending stress was applied. On the other hand, in Comparative Example 1 in which the adhesive layer was not formed, although the transparency was maintained, the adhesion between the fiber layer and the resin layer was poor, resulting in concern about practical problems. Moreover, also in Comparative Example 2 in which the urethane acrylate resin layer was not formed as the adhesive layer, the adhesion between the fiber layer and the resin layer was poor.

<Example 6 (Production Example 1 of multilayer laminate)>
The multilayer laminated body by which the resin layer was laminated | stacked on both surfaces of the fiber layer with the following procedure is obtained.
Two laminates obtained in any of Examples 1 to 5 are prepared, and water is applied to each fiber layer with a bar coater. Next, the fiber layer surfaces of the two laminates are bonded together, and a rubber roller is pressed from the resin layer side of one laminate and pressed. Furthermore, the laminated body bonded together is dried at 100 ° C. for 1 hour with a constant temperature dryer, whereby a multilayer laminated body in which the resin layers are laminated on both surfaces of the fiber layer is obtained.

<Example 7 (Production Example 2 of multilayer laminate)>
Two sheets of the laminate obtained in any of Examples 1 to 5 are prepared, and a UV curable acrylic adhesive (Z-587, manufactured by Aika Kogyo Co., Ltd.) is applied to each fiber layer with a bar coater. . Next, the fiber layer surfaces of the two laminates are bonded together, and a rubber roller is pressed from the resin layer side of one laminate and pressed. Further, UV light of 500 mJ / cm ² was irradiated three times from the resin layer side of the laminated body using a UV conveyor device (ECS-4011GX, manufactured by Eye Graphics Co., Ltd.), and the UV curable acrylic adhesive was applied. By curing, a multilayer laminate in which resin layers are laminated on both sides of the fiber layer is obtained.

<Example 8 (Production Example 3 of multilayer laminate)>
Using the laminate obtained in any of Examples 1 to 5, a multilayer laminate in which resin layers are laminated on both sides by the following procedure is obtained.
First, 100 parts by mass of an acrylic resin grafted with acryloyl groups (manufactured by Taisei Fine Chemical Co., Ltd., Acryt 8KX-012C) and 38 parts by mass of a polyisocyanate compound (manufactured by Asahi Kasei Chemicals Co., Ltd., TPA-100) are mixed to obtain a resin composition. obtain. Next, the resin composition is applied to the cellulose fiber-containing layer of the laminate with a bar coater. Furthermore, the multilayer laminated body by which the resin layer was laminated | stacked on both surfaces of the cellulose fiber content layer by heating at 100 degreeC for 1 hour and making it harden | cure is obtained.

<Example 9 (Production Example 1 of inorganic film laminate)>
For the laminate obtained in any of Examples 1 to 5 or the multilayer laminate obtained in any of Examples 6 to 8, with an atomic layer deposition apparatus (“SUNALE R-100B” manufactured by Picosun), An aluminum oxide film is formed. As an aluminum raw material, trimethylaluminum (TMA) and H ₂ O are used for the oxidation of TMA. The chamber temperature is set to 150 ° C., the TMA pulse time is 0.1 seconds, the purge time is 4 seconds, the H ₂ O pulse time is 0.1 seconds, and the purge time is 4 seconds. By repeating this cycle for 405 cycles, an inorganic film laminated body in which an aluminum oxide film having a thickness of 30 nm is laminated on both surfaces of the laminated body or the multilayer laminated body is obtained.

<Example 10 (Production Example 2 of inorganic film laminate)>
Plasma CVD device ("ICP-CVD roll-to-roll device" manufactured by Celbach) for the laminate obtained in any of Examples 1 to 5 or the multilayer laminate obtained in any of Examples 6 to 8 ) To form a silicon oxynitride film. Specifically, a laminate or a multilayer laminate is bonded to the upper surface of a carrier film (PET film) with a double-sided tape and placed in a vacuum chamber. The temperature in the vacuum chamber is set to 50 ° C., and the inflow gas is silane, ammonia, oxygen, and nitrogen. A plasma discharge is generated and film formation is performed for 45 minutes to obtain a laminate or an inorganic film laminate in which a silicon oxynitride film having a thickness of 500 nm is laminated on one surface of a multilayer laminate. Furthermore, by forming a film on the opposite surface in the same procedure, it is also possible to obtain a laminated body or an inorganic film laminated body in which a silicon oxynitride film having a film thickness of 500 nm is laminated on both surfaces of the multilayer laminated body. .

2 Fiber layer 4 Adhesive layer 6 Resin layer 10 Laminate 11 First layer 12 Second layer

Claims (9)

A fiber layer containing fibrous cellulose having a fiber width of 1000 nm or less;
An adhesive layer containing urethane (meth) acrylate resin;
A laminate in which resin layers are directly laminated in this order,
The resin layer includes a first layer disposed on the adhesive layer side, and a second layer disposed on one side of the first layer and opposite to the adhesive layer,
The first layer includes an acrylic resin, and the second layer includes a polycarbonate resin . The first layer laminate according to claim 1 comprising an alkyl (meth) acrylate resin. The first layer The laminate of claim 1 comprising epoxy (meth) acrylate resin. The laminate according to any one of claims 1 to 3 , wherein the resin layer is a coextruded film having the first layer and the second layer. The urethane (meth) acrylate resin contained in the adhesive layer includes a urethane unit and an acrylic unit, the content (mass%) of the urethane unit is P, and the content (mass%) of the acrylic unit is Q. In the case, P / Q is 0.1 or more and 0.9 or less, The laminate according to any one of claims 1 to 4 . The laminate according to any one of claims 1 to 5 , wherein the density of the fiber layer is 1.0 g / cm ³ or more. Obtaining a fiber layer containing fibrous cellulose having a fiber width of 1000 nm or less;
Applying a resin composition containing urethane (meth) acrylate directly on at least one surface of the fiber layer to form an adhesive layer;
A step of directly laminating a resin layer on one surface of the adhesive layer on the side opposite to the fiber layer, and a method for producing a laminate ,
The resin layer includes a first layer disposed on the adhesive layer side, and a second layer disposed on one side of the first layer and opposite to the adhesive layer,
The first layer includes an acrylic resin, and the second layer includes a polycarbonate resin . The first layer includes an epoxy (meth) acrylate resin,
The said resin layer is a manufacturing method of the laminated body of Claim 7 formed by apply | coating an epoxy (meth) acrylate containing composition on a said 2nd layer. The first layer includes an alkyl (meth) acrylate resin,
The method for producing a laminate according to claim 7 , wherein the resin layer is formed by co-extrusion of the first layer and the second layer.

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