JP2017087666A - Laminate and method for producing laminate - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a laminate which has high transparency and a sufficient strength and can exhibit excellent interlayer adhesion even when placed in a severe environment, and to provide a method for producing the laminate.SOLUTION: There is provided a laminate 100 which has a fiber layer 10, an adhesive layer 20 and a resin layer 30 in this order, where the fiber layer 10 contains fine fibrous cellulose having a fiber width of 1,000 nm or less, the adhesive layer 20 contains a functional group (A) forming a covalent bond with a (meth)acryloyl group and further contains at least one selected from a functional group (B) forming a covalent bond with a hydroxyl group and a hydrolyzable group of the functional group (B), and the resin layer 30 contains a polymer of an acrylic monomer.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a laminate and a method for producing the laminate. Specifically, the present invention relates to a laminate having a fiber layer containing fine fibrous cellulose, an adhesive layer containing a specific functional group, and a resin layer containing a polymer of an acrylic monomer.

  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. In addition, a sheet composed of such fine fibrous cellulose and a composite sheet including a fine fibrous cellulose-containing sheet and a resin layer have been developed. In the sheet | seat and composite sheet containing a 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.

  As the composite sheet, for example, a sheet obtained by dispersing and curing fine fibrous cellulose in a resin composition containing an acrylic monomer or the like (for example, Patent Documents 1 and 2), or porous fine fibrous cellulose. Sheets obtained by impregnating a containing sheet with a resin composition containing an acrylic monomer or the like (for example, Patent Documents 3 and 4) are known.

  Moreover, as a composite sheet containing a fine fibrous cellulose-containing sheet and a resin layer, a laminate in which a high-density non-porous fine fibrous cellulose-containing sheet and a resin layer are laminated via an adhesive layer is known (for example, And Patent Documents 5 to 7). Patent Documents 5 and 6 mainly include a resin layer (base material) made of a polyester resin or the like, an adhesive layer containing a polyester resin or the like having a carboxyl group, and a fine fiber shape made of fine fibrous cellulose having a carboxyl group. A laminate in which cellulose-containing sheets are laminated is disclosed. Here, in order to improve the adhesiveness of the resin layer, the surface of the resin layer is subjected to treatment such as corona treatment. Patent Document 7 discloses a laminate in which an acrylic resin layer, an adhesive layer containing a polyester resin, and a fine fibrous cellulose-containing sheet having a phosphate group are laminated.

JP 2012-167202 A JP 2012-252038 A JP 2006-316253 A JP 2008-106152 A JP 2014-079938 A International Publication No. WO2012 / 070441 International Publication No. WO2015 / 163281

As described above, various types of composite sheets have been developed. However, in the composite sheets of Patent Documents 1 and 2, the fine fibrous cellulose may aggregate in the resin composition, and in this case, there is a concern that the strength of the composite sheet is reduced. In order to prevent agglomeration of fine fibrous cellulose, a technique of dispersing hydrophobicized fine fibrous cellulose in the resin composition is also being studied. In this case, reinforcement derived from hydrogen bonding of the fine fibrous cellulose. There was a problem that the effect could not be obtained.
On the other hand, in the composite sheets of Patent Documents 3 and 4, there is a problem that the density of the fine fibrous cellulose is reduced due to the porosity of the fine fibrous cellulose, and the strength of the composite sheet cannot be obtained sufficiently.

  As described in Patent Documents 5 and 6, by laminating a resin layer and a fine fibrous cellulose-containing sheet, it has been studied to obtain a laminate having excellent durability and the like. There was a problem that strength and adhesion between each layer were not sufficient. Further, in the laminate of Patent Document 7, although the interlayer adhesion is improved, there is still room for improvement in the interlayer adhesion when placed under severe conditions of high temperature and high humidity. It became clear by examination of those.

  Therefore, in order to solve the problems of the prior art, the present inventors are a laminate having high transparency and sufficient strength, and excellent interlayer adhesion even in a harsh environment. The study was advanced for the purpose of providing a laminate capable of exhibiting the above.

As a result of intensive studies to solve the above problems, the present inventors have found that in a laminate including a fiber layer containing fine fibrous cellulose and a resin layer containing a polymer of an acrylic monomer, the fiber layer and the resin It has been found that by laminating a layer via an adhesive layer containing a specific functional group, excellent interlayer adhesion can be exhibited even in a harsh environment. In order to complete the present invention, the present inventors have found that such a laminate can exhibit excellent interlayer adhesion in a harsh environment in addition to having high transparency and sufficient strength. It came.
Specifically, the present invention has the following configuration.

[1] It has a fiber layer, an adhesive layer, and a resin layer in this order. The fiber layer contains fine fibrous cellulose having a fiber width of 1000 nm or less, and the adhesive layer is covalently bonded to a (meth) acryloyl group. And the functional group (B) that forms a covalent bond with a hydroxyl group and at least one selected from a hydrolyzable group of the functional group (B), and the resin layer is an acrylic monomer A laminate comprising the polymer of
[2] The functional group (A) is at least one selected from a (meth) acryloyl group and a group represented by H ₂ C═CR ² —CH (—OH) —. (Wherein R ² represents a hydrogen atom or a methyl group).
[3] The laminate according to [1] or [2], wherein the functional group (B) is at least one selected from an isocyanate group, a carbodiimide group, an epoxy group, an alkoxysilyl group, a silanol group, and an oxazoline group.
[4] The laminate according to any one of [1] to [3], wherein the adhesive layer includes a polymer having a functional group (A) and a compound having a functional group (B).
[5] After the laminate is placed for 240 hours under conditions of a temperature of 85 ° C. and a relative humidity of 85%, the number of peels in the 100 masses of the fiber layer is 10 or less when a crosscut test according to JIS K 5400 is performed. The laminate according to any one of [1] to [4].
[6] The laminate according to any one of [1] to [5], wherein the density of the fiber layer is 1.0 g / cm ³ or more.
[7] The laminate according to any one of [1] to [6], which has a tensile elastic modulus of 5 GPa or more.
[8] The laminate according to any one of [1] to [7], wherein the total light transmittance is 85% or more.
[9] The laminate according to any one of [1] to [8], wherein the adhesive layer further includes a polymerization initiator.
[10] The laminate according to any one of [1] to [9], wherein the resin layer further includes a polymerization initiator.
[11] The laminate according to any one of [1] to [10], wherein the adhesive layer is a coated adhesive layer, and the resin layer is a coated resin layer.
[12] On at least one surface of the fiber layer, an adhesive layer is formed by applying a composition containing a resin having a functional group (A) and a hydroxyl group and a compound having at least two functional groups (B). And the laminated body in any one of [1]-[11] manufactured by forming the resin layer by apply | coating the resin composition containing an acrylic monomer on an contact bonding layer.
[13] A step of obtaining a fiber layer containing fine fibrous cellulose having a fiber width of 1000 nm or less, a functional group (A) that forms a covalent bond with a (meth) acryloyl group, and a hydroxyl group on at least one surface of the fiber layer And a step of applying a composition containing a functional group (B) that forms a covalent bond to form an adhesive layer, and a step of applying a resin composition containing an acrylic monomer to form a resin layer. Manufacturing method.
[14] The functional group (A) is at least one selected from a (meth) acryloyl group and a group represented by H ₂ C═CR ² —CH (—OH) —. The manufacturing method of the laminated body of (However, R < ² > represents a hydrogen atom or a methyl group.).
[15] The functional group (B) is at least one selected from an isocyanate group, a carbodiimide group, an epoxy group, an alkoxysilyl group, a silanol group, and an oxazoline group. Production method.
[16] The composition containing the functional group (A) and the functional group (B) includes a resin having a functional group (A) and a hydroxyl group, and a compound having at least two functional groups (B). [15] The method for producing a laminate according to any one of [15].
[17] The method for producing a laminate according to any one of [13] to [16], wherein the composition containing the functional group (A) and the functional group (B) further includes a polymerization initiator.
[18] The method for producing a laminate according to any one of [13] to [17], wherein the resin composition further includes a polymerization initiator.

  ADVANTAGE OF THE INVENTION According to this invention, it is a laminated body which has high transparency and sufficient intensity | strength, Comprising: Even if it is a case where it is a severe environment, the laminated body which can exhibit the outstanding interlayer adhesiveness can be obtained.

FIG. 1 is a cross-sectional view for explaining an example of the layer structure of the laminate of the present invention. FIG. 2 is a cross-sectional view illustrating an example of the layer configuration of the laminate of the present invention. FIG. 3 is a cross-sectional view illustrating an example of the layer 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. FIG. 5 is a schematic diagram illustrating the structure of a glass cell for molding a resin layer in an embodiment.

  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.

(Laminate)
The present invention relates to a laminate having a fiber layer, an adhesive layer, and a resin layer in this order. In the laminate, the fiber layer contains fine fibrous cellulose having a fiber width of 1000 nm or less. The adhesive layer includes a functional group (A) that forms a covalent bond with a (meth) acryloyl group, and is further selected from a functional group (B) that forms a covalent bond with a hydroxyl group and a hydrolyzable group of the functional group (B). Including at least one of the following. The resin layer includes an acrylic monomer polymer.

  FIG. 1 is a cross-sectional view for explaining an example of the layer structure of the laminate of the present invention. As shown in FIG. 1, the laminate 100 of the present invention includes a fiber layer 10, an adhesive layer 20, and a resin layer 30 in this order. That is, in the laminate 100, the fiber layer 10 and the resin layer 30 are bonded via the adhesive layer 20.

  The laminate of the present invention has excellent transparency and strength because it has a fiber layer 10 containing fine fibrous cellulose, an adhesive layer 20 containing a specific functional group, and a resin layer 30 containing a polymer of an acrylic monomer. Yes. Furthermore, in the laminated body of this invention, durability is favorable. Here, that the durability is good means that the adhesion between the layers of the laminate is excellent, and that good adhesion is exhibited even under severe conditions such as high temperature and high humidity conditions. This is included in the composition in which the functional group (B) contained in the composition forming the adhesive layer 20 is covalently bonded to the hydroxyl group of the fine fibrous cellulose contained in the fiber layer 10 to form the adhesive layer 20. The functional group (A) that is formed forms a covalent bond with the acryloyl group contained in the resin layer 30, and the hydroxyl group and the functional group (B) that are contained in the composition that forms the adhesive layer 20 are further covalently bonded. This is considered to be achieved by forming That is, it is considered that the adhesion between the layers of the laminate is strengthened by forming a series of cross-linked structures that connect the fiber layer 10 and the resin layer 30 in the adhesive layer 20.

  The laminate 100 of the present invention may be a three-layer laminate 100 containing at least one fiber layer 10, an adhesive layer 20, and a resin layer 30, but any layer may be two or more layers. It may be a laminate of four or more layers. For example, as shown in FIG. 2, the laminate 100 of the present invention may be a laminate having a combination of the adhesive layer 20 and the resin layer 30 on both sides of the fiber layer 10, and may have a five-layer configuration. A laminated body may be sufficient. As shown in FIG. 3, the laminate 100 of the present invention may be a laminate having a combination of the adhesive layer 20 and the fiber layer 10 on both sides of the resin layer.

  When the laminated body has a configuration as shown in FIG. 2, the resin layer 30 can function as a layer that coats the surface of the fiber layer 10. When the laminate has a configuration as shown in FIG. 3, the fiber layer 10 may have a function of reinforcing the resin layer 30, and the fiber layer 10 can function as a reinforcing layer. . Thus, each layer can exhibit various functions depending on the application and configuration. Moreover, it is preferable that the thickness of each layer is suitably selected according to a use or a structure.

  The thickness of the resin layer is preferably 1 μm or more, more preferably 3 μm or more, and further preferably 5 μm or more. When the resin layer functions as a layer that coats the surface of the fiber layer, it may be a thin film. Further, the thickness of the resin layer is preferably 10 mm or less, and more preferably 5 mm or less. When the fiber layer is configured to reinforce the resin layer, the resin layer preferably has a certain thickness.

  The thickness of the fiber layer is preferably 1 μm or more, more preferably 3 μm or more, and further preferably 5 μm or more. The thickness of the fiber layer is preferably 1 mm or less, and more preferably 100 μm or less.

  The thickness of the adhesive layer is preferably 0.1 μm or more, more preferably 0.5 μm or more, and further preferably 1 μm or more. The thickness of the adhesive layer is preferably 100 μm or less, and more preferably 50 μm or less. By setting the adhesive layer thickness within the above range, interlayer adhesion in the laminate can be more effectively enhanced.

The laminate of the present invention is excellent in adhesion between the respective layers, and the fiber layer is firmly bonded to the resin layer via the adhesive layer. Specifically, in the crosscut test based on JIS K 5400 of the laminate, the number of peels in the fiber layer 100 mass is preferably 10 or less, more preferably 5 or less, and 3 or less. Is more preferable.
In addition, the adhesive evaluation method based on JIS K 5400 is specifically as follows. First, 100 cross cuts of 1 mm ² are put on the surface of the laminated body on the fiber layer side, cellophane tape (manufactured by Nichiban Co., Ltd.) is pasted thereon, pressed with a load of 1.5 kg / cm ² , and then 90 ° Count the number of squares peeled in the direction and peeled off (1 mm ² square squares). The number of squares is defined as the number of peels in 100 squares.

  The laminate of the present invention is also characterized in that the adhesion between each layer does not deteriorate even under severe conditions such as high temperature and high humidity conditions. Even when the laminate is placed under high temperature and high humidity conditions for a long time, the fiber layer is firmly bonded to the resin layer via the adhesive layer. Specifically, the number of peels in 100 masses of the fiber layer when the cross cut test according to JIS K 5400 is performed after placing the laminate under conditions of a temperature of 85 ° C. and a relative humidity of 85% for 240 hours is 20. Is preferably 10 or less, more preferably 10 or less, still more preferably 5 or less, and particularly preferably 3 or less.

  The tensile elastic modulus of the laminate of the present invention is preferably 5 GPa or more, more preferably 7 GPa or more, and further preferably 9 GPa or more. The tensile elastic modulus of the laminate is a value measured according to JIS P 8113, and is a tensile elastic modulus at a temperature of 23 ° C. and a relative humidity of 50%. As the tensile tester, Tensile Tester CODE SE-064 manufactured by L & W, Inc. can be used.

  The total light transmittance of the laminate of the present invention is preferably 85% or more, more preferably 87% or more, and further preferably 90% or more. The total light transmittance of the laminate is a value measured with a haze meter (HM-150, manufactured by Murakami Color Research Laboratory) in accordance with JIS K 7361.

  The haze value of the laminate of the present invention is preferably 20% or less, more preferably 15% or less, and even more preferably 10% or less. The haze value of the laminate is a value measured using a haze meter (manufactured by Murakami Color Research Laboratory Co., Ltd., HM-150) according to JIS K 7136.

The laminate of the present invention has at least two functional groups (A) and a hydroxyl group-containing resin and at least two functional groups (B) on at least one surface of a fiber layer containing fine fibrous cellulose having a fiber width of 1000 nm or less. It is manufactured by forming a resin layer by applying a resin composition containing an acrylic monomer on the adhesive layer after forming the adhesive layer by applying a composition containing the compound having Is preferred. That is, in the laminate of the present invention, the adhesive layer is preferably a coated adhesive layer, and the resin layer is also preferably a coated resin layer. Here, a coating adhesive layer is a layer obtained by apply | coating a composition as mentioned above, and making it harden | cure after that. Moreover, a coating resin layer is a layer obtained by apply | coating the resin composition containing an acrylic monomer, and making it harden | cure after that.
In the present invention, by forming the adhesive layer and the resin layer by the above method, a series of cross-linked structures that connect the fiber layer and the resin layer are formed in the adhesive layer. For this reason, it becomes possible to improve the interlayer adhesiveness in a laminated body more effectively.

(Fiber layer)
The fiber layer contains fine 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. Is more preferable, and it is especially preferable that it is 90 mass% or more.

<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. Further, semi-chemical pulps such as semi-chemical pulp (SCP) and chemiground wood pulp (CGP), mechanical pulps such as ground wood pulp (GP), and thermomechanical pulp (TMP, BCTMP) are exemplified, but not limited thereto. 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. Sheets containing long fibrous fine fibrous cellulose having a large axial ratio tend 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 average fiber width of the fine fibrous cellulose by observation with an electron microscope 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).

<Chemical treatment>
Fine fibrous cellulose can be obtained by defibrating a cellulose raw material. Moreover, in this invention, it is preferable to perform a chemical process to a cellulose raw material before a fibrillation process, and to add a substituent to a fine fibrous cellulose. The substituent added to the fine fibrous cellulose is preferably an ionic substituent, and more preferably an anionic substituent. Examples of the anionic substituent include a phosphate group or a substituent derived from a phosphate group (sometimes simply referred to as a phosphate group), at least one substituent selected from a carboxyl group and a sulfone group. it can. Among these, the anionic substituent is preferably at least one selected from a phosphate group and a carboxyl group, and more preferably a phosphate group.

  The fine fibrous cellulose used in the present invention preferably has an anionic substituent of 0.1 mmol / g to 3.5 mmol / g per 1 g (mass) of the fine fibrous cellulose. The fine fibrous cellulose having the above-mentioned anionic substituent in the above ratio is preferable in that it can be ultrafine due to the electrostatic repulsion effect.

<General chemical treatment>
The method of chemical treatment of the cellulose raw material is not particularly limited as long as it is a method capable of obtaining fine fibers. Examples of the chemical treatment include acid treatment, ozone treatment, TEMPO (2,2,6,6-tetramethylpiperidine-1-oxyl radical) oxidation treatment, enzyme treatment, and covalent bond with a functional group in cellulose or fiber raw material. Treatment with a compound capable of forming.

Examples of acid treatment include Otto van den Berg; Jeffrey R. Capadona; Christoph Weder;
The method described in Biomacromolecules 2007, 8, 1353-1357. Can be mentioned. Specifically, the fine fibrous cellulose is hydrolyzed with sulfuric acid, hydrochloric acid, or the like. Those produced by high-concentration acid treatment are almost decomposed in non-crystalline regions and have short fibers (also called cellulose nanocrystals), which are also included in fine fibrous cellulose.

  As an example of the ozone treatment, a method described in JP 2010-254726 A can be exemplified, but it is not particularly limited. Specifically, after the fiber is treated with ozone, it is dispersed in water, and the resulting aqueous suspension of the fiber is pulverized.

  An example of TEMPO oxidation includes the method described in Saito T & al. Homogeneous suspensions of individualized microfibrils from TEMPO-catalyzed oxidation of native cellulose. Biomacromolecules 2006, 7 (6), 1687-91. Specifically, after the fiber is subjected to TEMPO oxidation treatment, it is dispersed in water, and the aqueous suspension of the obtained fiber is pulverized.

  As an example of the enzyme treatment, the method described in WO2013 / 176033 (all contents described in WO2013 / 176033 shall be cited in the present specification) can be mentioned, but is not particularly limited. . Specifically, the fiber raw material is treated with an enzyme at least under a condition where the ratio of the enzyme EG activity to the CBHI activity is 0.06 or more.

  The treatment with a compound capable of forming a covalent bond with a functional group in cellulose or a fiber raw material is described in International Publication WO2013 / 073652 (PCT / JP2012 / 079743) “an oxo acid containing a phosphorus atom in its structure, And a method using at least one compound selected from polyoxoacids or salts thereof.

<Introduction of anionic substituent>
The fine fibrous cellulose preferably has an anionic substituent. Among these, the anionic group is preferably at least one selected from a phosphate group, a carboxyl group, and a sulfone group, more preferably at least one selected from a phosphate group and a carboxyl group, Particularly preferred is an acid group.

<Introduced amount of substituent>
The amount of the anionic substituent introduced is not particularly limited, but is preferably 0.1 mmol / g or more, more preferably 0.2 mmol / g or more, per 1 g (mass) of fine fibrous cellulose. / G or more is more preferable, and 0.5 mmol / g or more is particularly preferable. The amount of anionic substituent introduced is preferably 3.5 mmol / g or less, more preferably 3.0 mmol / g or less, further preferably 2.5 mmol / g or less. Particularly preferred is 0 mmol / g or less. By making the introduction amount of the anionic substituent within the above range, the fiber raw material can be easily miniaturized, and the stability of the fine fibrous cellulose can be enhanced.

<Introduction of phosphate group>
In the present invention, the fine fibrous cellulose preferably has a phosphate group or a substituent derived from the phosphate group.

<Phosphate group introduction process>
The phosphoric acid group introduction step can be performed by reacting a fiber raw material containing cellulose with at least one selected from a compound having a phosphate group and a salt thereof (hereinafter referred to as “compound A”). . Such a compound A may be mixed in a powder or aqueous solution with a dry or wet fiber raw material. As another example, a powder of compound A or an aqueous solution may be added to the fiber raw material slurry.

  The phosphoric acid group introducing step can be performed by reacting at least one (compound A) selected from a compound having a phosphoric acid group and a salt thereof 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, sodium phosphate, from the viewpoint of high phosphate group introduction efficiency, easy defibration efficiency in the defibration process described later, low cost, and easy industrial application. A salt, or a potassium salt of phosphoric acid or an ammonium salt of phosphoric acid is 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 3 or more and 7 or less from the viewpoint of suppressing 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 is preferably 0.5% by mass or more and 100% by mass or less. More preferably, they are more than 50 mass% and most preferably 2 mass% or more and 30 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 following lower limit.

  Examples of the compound B used in this embodiment include urea, thiourea, biuret, phenylurea, benzylurea, dimethylurea, diethylurea, tetramethylurea, benzoleinurea, and hydantoin. Among these, urea is preferable because it is easy to handle at low cost and easily forms a hydrogen bond with a fiber raw material having a hydroxyl group.

  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 is preferably 1% 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 150 ° 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, the amount of phosphate groups introduced can be within a preferred range by setting the heating temperature and the heating time to appropriate ranges.

<Introduction amount of phosphate group>
The amount of phosphate group introduced is preferably 0.1 mmol / g or more, more preferably 0.2 mmol / g or more, and 0.3 mmol / g or more per 1 g (mass) of fine fibrous cellulose. More preferably, it is particularly preferably 0.5 mmol / g or more. The amount of phosphate group introduced is preferably 3.5 mmol / g or less, more preferably 3.0 mmol / g or less, further preferably 2.5 mmol / g or less, and 2.0 mmol / G or less is particularly preferable. By making the introduction amount of the phosphate group within the above range, the fiber raw material can be easily refined, and the stability of the fine fibrous cellulose can be enhanced.

  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.

<Introduction of carboxyl group>
In the present invention, when the fine fibrous cellulose has a carboxyl group, for example, a compound having a carboxylic acid-derived group, a derivative thereof, or an acid anhydride or a derivative thereof, such as the TEMPO oxidation treatment described above. A carboxyl group can be introduce | transduced by processing by.

  The compound having a carboxyl group is not particularly limited, and examples thereof include dicarboxylic acid compounds such as maleic acid, succinic acid, phthalic acid, fumaric acid, glutaric acid, adipic acid and itaconic acid, and tricarboxylic acid compounds such as citric acid and aconitic acid. .

  The acid anhydride of the compound having a carboxyl group is not particularly limited, but examples thereof include acid anhydrides of dicarboxylic acid compounds such as maleic anhydride, succinic anhydride, phthalic anhydride, glutaric anhydride, adipic anhydride, and itaconic anhydride. It is done.

  Although it does not specifically limit as a derivative of the compound which has a carboxyl group, The derivative of the acid anhydride of the compound which has a carboxyl group and the acid anhydride imidation of a compound which has a carboxyl group are mentioned. Although it does not specifically limit as an acid anhydride imidation thing of a compound which has a carboxyl group, Imidation thing of dicarboxylic acid compounds, such as maleimide, succinic acid imide, and phthalic acid imide, is mentioned.

  The acid anhydride derivative of the compound having a carboxyl group is not particularly limited. For example, at least some of the hydrogen atoms of the acid anhydride of the compound having a carboxyl group, such as dimethylmaleic anhydride, diethylmaleic anhydride, diphenylmaleic anhydride, etc. are substituted (for example, alkyl group, phenyl group, etc. ) Are substituted.

<Introduction amount of carboxyl group>
The amount of carboxyl groups introduced is preferably 0.1 mmol / g or more, more preferably 0.2 mmol / g or more, and 0.3 mmol / g or more per 1 g (mass) of fine fibrous cellulose. Is more preferably 0.5 mmol / g or more. The amount of carboxyl group introduced is preferably 3.5 mmol / g or less, more preferably 3.0 mmol / g or less, further preferably 2.5 mmol / g or less, and 2.0 mmol / g. It is particularly preferred that it is g or less. By making the introduction amount of the carboxyl group within the above range, the fiber raw material can be easily refined, and the stability of the fine fibrous cellulose can be enhanced.

<Cationic substituent introduction>
In this embodiment, a cationic substituent may be introduced into the fine fibrous cellulose as an ionic substituent. For example, a cationic substituent can be introduced into the fiber raw material by adding a cationizing agent and an alkali compound to the fiber raw material and causing the fiber raw material to react.
As the cationizing agent, one having a quaternary ammonium group and a group that reacts with a hydroxyl group of cellulose can be used. Examples of the group that reacts with the hydroxyl group of cellulose include an epoxy group, a functional group having a halohydrin structure, a vinyl group, and a halogen group. Specific examples of the cationizing agent include glycidyltrialkylammonium halides such as glycidyltrimethylammonium chloride and 3-chloro-2-hydroxypropyltrimethylammonium chloride or halohydrin type compounds thereof.
The alkali compound contributes to the promotion of the cationization reaction. Alkali compounds include alkali metal hydroxides or alkaline earth metal hydroxides, alkali metal carbonates or alkaline earth metal carbonates, alkali metal phosphates or alkaline earth metal phosphates, etc. Organic alkali compounds such as ammonia, aliphatic amines, aromatic amines, aliphatic ammoniums, aromatic ammoniums, heterocyclic compounds and their hydroxides, carbonates, phosphates, etc. It may be. The introduction amount of the cationic substituent can be measured using, for example, elemental analysis.

<Alkali treatment>
In the case of producing fine fibrous cellulose, alkali treatment can be performed between the substituent introduction step and the defibration treatment step described 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 ionic substituent-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 device for wet grinding such as a disk type 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, a polar organic solvent can be used in addition to water. 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 having a phosphate 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. The fine fibrous cellulose-containing slurry is formed into a sheet by a method described later to form a fiber layer.

<Density of fiber layer>
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. Moreover, it is preferable that the density of a fiber layer is 2.0 g / cm < ³ > or less. 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 based on JIS P 8124. 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.

<Other ingredients>
Examples of other components contained in the fiber layer include hydrophilic polymers and organic ions. Examples of hydrophilic polymers include polyethylene glycol, cellulose derivatives (hydroxyethyl cellulose, carboxyethyl cellulose, carboxymethyl cellulose, etc.), casein, dextrin, starch, modified starch, polyvinyl alcohol, modified polyvinyl alcohol (acetoacetylated polyvinyl alcohol, etc.), Examples thereof include polyethylene oxide, polyvinyl pyrrolidone, polyvinyl methyl ether, polyacrylates, polyacrylamide, alkyl acrylate copolymer, urethane copolymer, and the like. 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.

(Adhesive layer)
The adhesive layer includes a functional group (A) that forms a covalent bond with a (meth) acryloyl group, and is further selected from a functional group (B) that forms a covalent bond with a hydroxyl group and a hydrolyzable group of the functional group (B). Including at least one. That is, the adhesive layer includes a functional group (A) and a group derived from the functional group (B) or the functional group (B). In this invention, the interlayer adhesiveness in a laminated body can be improved by making an adhesive layer contain such a multiple types of functional group.

  The adhesive layer preferably includes the compound a having the functional group (A) and the compound b having the functional group (B), but each molecule of the functional group (A) and the functional group (B) is one molecule at a time. The compound which it has in may be included. In addition, it is preferable that the compound a which has a functional group (A) is a polymer (resin) which has a functional group (A), and both a functional group (A) and a functional group (B) are contained in one molecule. In such a case, such a compound is also preferably a polymer (resin).

The functional group (A) that forms a covalent bond with the (meth) acryloyl group includes a (meth) acryloyl group (H ₂ C═CR ¹ —C (═O) —) and H ₂ C═CR ² —CH ( It is preferably at least one selected from the group represented by —OH) —. In the present specification, “(meth) acryloyl group” means an acryloyl group or a methacryloyl group. R ¹ and R ² are a hydrogen atom or a methyl group.
In the present invention, the polymer (resin) having the functional group (A) is at least one selected from a (meth) acryloyl group and a group represented by H ₂ C═CR ² —CH (—OH) —. Is preferably an acrylic resin having at least one selected from a (meth) acryloyl group and a group represented by H ₂ C═CR ² —CH (—OH) —. More preferably, it is particularly preferable that the (meth) acryloyl group and the acrylic resin in which both of the groups represented by H ₂ C═CR ² —CH (—OH) — are graft-polymerized are used.

The functional group (B) that forms a covalent bond with a hydroxyl group is preferably at least one selected from an isocyanate group, a carbodiimide group, an epoxy group, an alkoxysilyl group, a silanol group, and an oxazoline group, and is an isocyanate group. Is more preferable.
The hydrolyzable group of the functional group (B) is a group obtained by hydrolyzing the functional group described above, and is a group derived from the functional group (B).

  The compound b having a functional group (B) is preferably an isocyanate compound. Examples of the isocyanate compound include tolylene diisocyanate, xylylene diisocyanate, hexamethylene diisocyanate, and isophorone diisocyanate. The isocyanate compound includes polyisocyanates such as biuret type, nurate type, and adduct type, and such polyisocyanate can also be used. Of these, nurate type polyisocyanate is preferable from the viewpoint of suppressing coloring due to heating and deterioration over time. The compound b detected in the adhesive layer may be a hydrolyzed group obtained by hydrolyzing at least one isocyanate group of the above isocyanate compound.

  The functional group (A) is a group that forms a covalent bond with the acryloyl group of the acrylic monomer polymer contained in the resin layer. The functional group (B) is a group that forms a covalent bond with the hydroxyl group of the fine fibrous cellulose contained in the fiber layer. Furthermore, the functional group (B) is a group covalently bonded to a hydroxyl group contained in the compound having the functional group (A). For example, the functional group (B) is a group covalently bonded to a hydroxyl group in the following structure contained in the adhesive layer, but the group to which the functional group (B) is covalently bonded is not limited thereto.

In the above structural formula, R ² represents a hydrogen atom or a methyl group.

  For example, the compound a having at least one functional group (A) and one hydroxyl group and the compound b having two or more functional groups (B) in one molecule are contained in the adhesive composition forming the adhesive layer. The hydroxyl group of compound a first forms a covalent bond with the first functional group (B) of compound b, and the functional group (A) of compound a is an acryloyl possessed by a polymer of acrylic monomers contained in the resin layer. Form a covalent bond with the group. And the 2nd functional group (B) of the compound b forms a covalent bond with the hydroxyl group which the fine fibrous cellulose contained in a fiber layer has. Thus, the fine fibrous cellulose contained in the fiber layer and the polymer of the acrylic monomer contained in the resin layer are linked by a crosslinked structure in which the functional groups of the compound a and the compound b are covalently bonded. That is, the component contained in the adhesive layer forms a covalent bond with any of the component contained in the fiber layer and the component contained in the resin layer. Since the adhesive layer includes a series of cross-linked structures as described above, it is considered that the adhesion between the layers in the laminate is improved.

The adhesive layer is preferably a coated adhesive layer formed by coating, and the composition (coating liquid) forming the adhesive layer includes a compound a having at least one functional group (A) and one hydroxyl group, and a functional group. It is preferable that the compound b which has two or more groups (B) in 1 molecule is contained. More preferably, the compound a has a (meth) acryloyl group and at least one group represented by H ₂ C═CR ² —CH (—OH) —. When two or more groups represented by H ₂ C═CR ² —CH (—OH) — are contained as the functional group (A) contained in the compound a, the first H ₂ C═CR ² The group represented by —CH (—OH) — is counted as the functional group (A), and the second group represented by H ₂ C═CR ² —CH (—OH) — is the number of hydroxyl groups. Is counted as
When the adhesive layer is formed, it includes a step of curing after applying such a composition, and in this curing step, each functional group forms a covalent bond. In the cured adhesive layer, the remaining functional groups (A) and functional groups (B) that have not been subjected to covalent bonding will be detected. In addition, since the functional group (B) contained in the adhesive layer may be easily hydrolyzed, the hydrolyzable group of the functional group (B) may be detected from the adhesive layer instead of the functional group (B). Good. Further, a structure in which each functional group is covalently bonded may be detected to confirm that each functional group is included.

In addition, although a functional group (B) is a group which forms a covalent bond with the hydroxyl group which the fine fibrous cellulose contained in a fiber layer has, even if it forms a covalent bond with the other substituent which a fine fibrous cellulose has. Good. For example, you may form a covalent bond with -O ^{< - >} Na ^<+> of the phosphate group which is an ionic substituent which fine fibrous cellulose has.

  Examples of the functional group (A), the functional group (B), and the hydrolyzable group detection device for the functional group (B) include a nuclear magnetic resonance analyzer, an infrared spectrometer, an X-ray photoelectron analyzer, and a Raman spectrometer. Etc. When detecting the functional group (A), the functional group (B), or the hydrolyzable group of the functional group (B) contained in the adhesive layer, the cross section of the adhesive layer may be analyzed, and the laminate is formed by physical polishing. The polished surface may be analyzed after polishing and exposing the adhesive layer.

  The adhesive layer preferably contains a resin, and more preferably contains a polymer (resin) having a functional group (A). That is, the adhesive layer is preferably a layer obtained by polymerizing and curing a curable composition containing a curable monomer component constituting such a resin by a known curing method. Examples of the curing method include thermal curing and radiation curing, and thermal curing is preferable. Examples of radiation include infrared rays, visible rays, ultraviolet rays, electron beams, and the like, but light that is an electromagnetic wave having a wavelength of 1 nm to 1000 nm is preferable. More preferred is an electromagnetic wave having a wavelength of 200 nm to 450 nm, and still more preferred is an ultraviolet ray having a wavelength of 300 nm to 400 nm.

  The curable composition for forming the adhesive layer preferably contains a polymerization initiator. For this reason, since at least a part of the polymerization initiator remains in the adhesive layer, the adhesive layer preferably contains a polymerization initiator. When the curable composition contains a polymerization initiator, the hardness of the adhesive layer can be adjusted.

  It is preferable to add a thermal polymerization initiator that generates radicals and acids by heating to the curable composition. It is also preferable to add a photopolymerization initiator that generates radicals and acids by radiation such as ultraviolet rays to the curable composition. In addition, you may employ | adopt the method of adding both a thermal-polymerization initiator and a photoinitiator to a curable composition, and polymerizing by the combination of a heat | fever and light.

Examples of the thermal polymerization initiator include hydroperoxide, dialkyl peroxide, peroxyester, diacyl peroxide, peroxycarbonate, peroxyketal, and ketone peroxide. Specifically, benzoyl peroxide, diisopropyl peroxy carbonate, t-butyl peroxy (2-ethylhexanoate) dicumyl peroxide, di-t-butyl peroxide, t-butyl peroxybenzoate, t-butyl hydro Peroxide, diisopropylbenzene hydroperoxide, 1,1,3,3-tetramethylbutyl hydroperoxide, or the like can be used. These polymerization initiators may be used alone or in combination of two or more.
When thermal polymerization is initiated during light irradiation, it becomes difficult to control the polymerization. Therefore, the thermal polymerization initiator preferably has a 1 minute half-life temperature of 120 ° C. or higher and 300 ° C. or lower.

  The addition amount of the thermal polymerization initiator is preferably 0.1% by mass or more and 2% by mass or less, and more preferably 0.3% by mass or more and 1% by mass or less with respect to the total mass of the curable monomer component. preferable.

  Examples of the photopolymerization initiator include a photoradical generator and a photocationic polymerization initiator. A photoinitiator may be used independently or may use 2 or more types together.

  Examples of the photo radical generator include benzophenone, benzoin methyl ether, benzoin propyl ether, diethoxyacetophenone, 1-hydroxycyclohexyl phenyl ketone, 2,6-dimethylbenzoyl diphenylphosphine oxide, or 2,4,6-trimethylbenzoyl diphenyl. Hosifin oxide and the like. Among these, benzophenone or 2,4,6-trimethylbenzoyldiphenylphosphine oxide is preferable.

  A photocationic polymerization initiator is a compound that initiates cationic polymerization upon irradiation with radiation such as ultraviolet rays or electron beams, such as aromatic sulfonium salts, aromatic iodonium salts, aromatic diazonium salts, aromatic ammonium salts, and the like. Can be mentioned.

  Examples of aromatic sulfonium salts include bis [4- (diphenylsulfonio) phenyl] sulfide bishexafluorophosphate, bis [4- (diphenylsulfonio) phenyl] sulfide bishexafluoroantimonate, and bis [4- (diphenylsulfonio). ) Phenyl] sulfide bishexafluoroborate, bis [4- (diphenylsulfonio) phenyl] sulfide tetrakis (pentafluorophenyl) borate, diphenyl-4- (phenylthio) phenylsulfonium hexafluoro, diphenyl-4- (phenylthio) Phenylsulfonium hexafluoroantimonate, diphenyl-4- (phenylthio) phenylsulfonium tetrafluoroborate, diphenyl-4- (phenylthio) phenylsulfo Um tetrakis (pentafluorophenyl) borate, triphenylsulfonium hexafluorophosphate, triphenylsulfonium hexafluoroantimonate, triphenylsulfonium tetrafluoroborate, triphenylsulfonium tetrakis (pentafluorophenyl) borate, bis [4- (di (4 -(2-hydroxyethoxy)) phenylsulfonio) phenyl] sulfide bishexafluorophosphate, bis [4- (di (4- (2-hydroxyethoxy)) phenylsulfonio) phenyl] sulfide bishexafluoroantimonate Bis [4- (di (4- (2-hydroxyethoxy)) phenylsulfonio) phenyl] sulfide tetrafluoroborate, or bis [4- (di (4- (2 Hydroxyethoxy)) phenylsulfonyl O) phenyl] sulfide tetrakis (pentafluorophenyl) borate, and the like.

  Aromatic iodonium salts include diphenyliodonium hexafluorophosphate, diphenyliodonium hexafluoroantimonate, diphenyliodonium tetrafluoroborate, diphenyliodonium tetrakis (pentafluorophenyl) borate, bis (dodecylphenyl) iodonium hexafluoroantimonate, bis (dodecyl) Phenyl) iodonium tetrakis (pentafluorophenyl) borate, 4-methylphenyl-4- (1-methylethyl) phenyliodonium hexafluorophosphate, 4-methylphenyl-4- (1-methylethyl) phenyliodonium hexafluoroantimonate, 4-methylphenyl-4- (1-methylethyl) phenyliodonium hexafluoroborate Or 4-methylphenyl-4- (1-methylethyl) phenyl iodonium tetrakis (pentafluorophenyl) borate, and the like.

  Examples of the aromatic diazonium salt include phenyldiazonium hexafluorophosphate, phenyldiazonium hexafluoroantimonate, diphenyliodonium tetrafluoroborate, diphenyliodonium tetrakis (pentafluorophenyl) borate, and the like.

  Examples of aromatic ammonium salts include 1-benzyl-2-cyanopyridinium hexafluorophosphate, 1-benzyl-2-cyanopyridinium hexafluoroantimonate, 1-benzyl-2-cyanopyridinium tetrafluoroborate, 1-benzyl-2- Cyanopyridinium tetrakis (pentafluorophenyl) borate, 1- (naphthylmethyl) -2-cyanopyridinium hexafluorophosphate, 1- (naphthylmethyl) -2-cyanopyridinium hexafluoroantimonate, 1- (naphthylmethyl) -2- Examples thereof include cyanopyridinium tetrafluoroborate and 1- (naphthylmethyl) -2-cyanopyridinium tetrakis (pentafluorophenyl) borate. (2,4-Cyclopentadien-1-yl) [(1-methylethyl) benzene] -iron salt includes (2,4-cyclopentadien-1-yl) [(1-methylethyl) benzene] -iron. (II) hexafluorophosphate, (2,4-cyclopentadien-1-yl) [(1-methylethyl) benzene] -iron (II) hexafluoroantimonate, (2,4-cyclopentadien-1-yl) [(1-Methylethyl) benzene] -iron (II) tetrafluoroborate, (2,4-cyclopentadien-1-yl) [(1-methylethyl) benzene] -iron (II) tetrakis (pentafluorophenyl) Examples include borate.

  Examples of commercially available products of these photocationic polymerization initiators include UVI6990, UVI6979 manufactured by Union Carbide, SP-150, SP-170, or SP-172 manufactured by ADEKA, Irgacure 261 manufactured by Ciba Geigy, or Irgacure. 250, Rhodia SIL PI2074, JMF-2456 manufactured by Rhodia, or San-Aid SI-60L, SI-80L, SI-100L, SI-110L, SI-180L, or SI-100L manufactured by Sanshin Chemical Industry Co., Ltd. .

  Furthermore, in addition to the cationic photopolymerization initiator, a curing agent for curing the cationic polymerizable monomer may be added. Examples of the curing agent include amine compounds, compounds such as polyaminoamide compounds synthesized from amine compounds, tertiary amine compounds, imidazole compounds, hydrazide compounds, melamine compounds, acid anhydrides, phenol compounds, thermal latent cationic polymerization catalysts. Or dicyanamide and derivatives thereof.

  Moreover, a photosensitizer can also be added. Specific examples include pyrene, perylene, acridine orange, thioxanthone, 2-chlorothioxanthone, and benzoflavin.

  The addition amount of the photopolymerization initiator is preferably 0.001% by mass to 5% by mass and more preferably 0.01% by mass to 2% by mass with respect to the total mass of the curable monomer component. Preferably, it is 0.05 mass% or more and 0.1 mass% or less.

(Resin layer)
The resin layer includes a polymer of an acrylic monomer. The resin layer is preferably a coating resin layer formed by coating, and the coating liquid (resin composition) for forming the resin layer preferably contains an acrylic monomer.

  The resin layer is preferably a coated resin layer formed by coating, and is preferably a layer obtained by polymerizing and curing a resin composition containing an acrylic monomer by a known curing method. Examples of the curing method include heat curing and radiation curing, and radiation curing is preferable.

  It is preferable that a polymerization initiator is contained in the resin composition forming the resin layer. For this reason, since at least a part of the polymerization initiator remains in the resin layer, the resin layer preferably contains a polymerization initiator. In addition, as a polymerization initiator added to a resin composition, the thermal polymerization initiator and photoinitiator which were mentioned above can be illustrated.

  The coating liquid (resin composition) for forming the resin layer may contain an acrylic monomer or a prepolymer of the acrylic monomer. A prepolymer may be comprised from 1 type of acrylic monomers mentioned later, and may be comprised combining 2 or more types. The prepolymer may be a copolymer obtained by copolymerizing an acrylic monomer described later with a urethane structure or an epoxy structure.

  Examples of acrylic monomers include 1,4-butanediol di (meth) acrylate, 1,6-hexanediol di (meth) acrylate, neopentyl glycol di (meth) acrylate, polyethylene glycol di (meth) acrylate, and neopentyl. Glycol adipate di (meth) acrylate, hydroxypivalate neopentyl glycol di (meth) acrylate, dicyclopentanyl di (meth) acrylate, caprolactone modified dicyclopentenyl di (meth) acrylate, EO modified phosphoric acid di (meth) acrylate Allylated cyclohexyl di (meth) acrylate, isocyanurate di (meth) acrylate, trimethylolpropane tri (meth) acrylate, ethylene oxide modified trimethylolpropane tri (meth) ) Acrylate, dipentaerythritol tri (meth) acrylate, propionic acid modified dipentaerythritol tri (meth) acrylate, pentaerythritol tri (meth) acrylate, PO modified trimethylolpropane tri (meth) acrylate, tris (acryloxyethyl) isocyania Nurate, pentaerythritol tetraacrylate, ditrimethylolpropane tetraacrylate, dipentaerythritol penta (meth) acrylate propionic acid modified dipentaerythritol penta (meth) acrylate, dipentaerythritol hexa (meth) acrylate, caprolactone modified dipentaerythritol hexa (meth) ) Acrylate, 1,10-decanediol diacrylate and the like. Among these, the acrylic monomer is preferably at least one selected from pentaerythritol tetraacrylate, dipentaerythritol hexaacrylate, and 1,10-decanediol diacrylate. An acrylic monomer may be used individually by 1 type, and may be used in combination of 2 or more type.

  Moreover, it is also preferable to use together monofunctional alkyl (meth) acrylate with the polyfunctional acrylic monomer mentioned above as an acrylic monomer. Examples of monofunctional alkyl (meth) acrylates include pentyl (meth) acrylate, hexyl (meth) acrylate, heptyl (meth) acrylate, n-octyl (meth) acrylate, isooctyl (meth) acrylate, N-nonyl (meth) acrylate, isononyl (meth) acrylate, n-decyl (meth) acrylate, isodecyl (meth) acrylate, n-undecyl (meth) acrylate, lauryl (meth) acrylate, (meth ) Stearyl acrylate, isostearyl (meth) acrylate, isobornyl (meth) acrylate, 2-ethylhexyl (meth) acrylate, and the like.

  In addition, in the acrylic resin which uses pentaerythritol tetraacrylate and dipentaerythritol hexaacrylate as a monomer component, there exists a tendency for the shrinkage | contraction at the time of hardening to be large. For this reason, when such a monomer component is used, it tends to be more difficult to improve the adhesion between the adhesive layer and the fiber layer and the resin layer. In the present invention, the adhesive layer has a specific functional group. Therefore, even when a monomer component having a large shrinkage at the time of curing is used, the interlayer adhesion was successfully improved.

(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 formation method of an inorganic layer is not specifically 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 heated catalyst body. Specific examples of the PVD method include vacuum deposition, ion plating, and sputtering.

  In addition, 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, lower the temperature, and reduce the 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.

(Laminate manufacturing method)
The present invention also relates to a method for producing a laminate. The production process of the laminate of the present invention includes a step of obtaining a fiber layer containing fine fibrous cellulose having a fiber width of 1000 nm or less, and a function of forming a covalent bond with a (meth) acryloyl group on at least one surface of the fiber layer. Applying a composition containing a group (A) and a functional group (B) that forms a covalent bond with a hydroxyl group to form an adhesive layer, and applying a resin composition containing an acrylic monomer to form a resin layer And a process.

<Process for obtaining a fiber layer containing fine fibrous cellulose>
The step of obtaining a fiber layer containing fine fibrous cellulose includes a step of applying a fine fibrous cellulose-containing slurry onto a substrate or a step of making a paper of the fine fibrous cellulose-containing slurry. Especially, it is preferable that the process of obtaining the fiber layer containing a fine fibrous cellulose includes the process of apply | coating a fine fibrous cellulose containing slurry on a base material.

<Coating process>
In the coating process, a fine fibrous cellulose-containing slurry is applied onto a substrate, and the fine fibrous cellulose-containing sheet formed by drying this is peeled from the substrate to obtain a sheet (fiber layer). It is a process. By using a coating apparatus and a long base material, sheets can be continuously produced. Although the density | concentration of the slurry to apply is not specifically limited, 0.05 mass% or more and 5 mass% or less are preferable.

  The quality of the base material used in the coating process is not particularly limited, but the one with higher wettability to the fine fibrous cellulose-containing slurry may be able to suppress the 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 viscosity of the fine fibrous cellulose-containing slurry is low and expands on the base material, to obtain a fine fibrous cellulose-containing sheet of a predetermined thickness and basis weight, for damming on the base material 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-containing slurry, for example, a roll coater, a gravure coater, a die coater, a curtain coater, an air doctor coater, or the like can be used. A die coater, a curtain coater, and a spray coater are 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, more preferably 25 ° C or higher and 40 ° C or lower, and further preferably 27 ° C or higher and 35 ° C or lower. If the coating temperature is equal to or higher than the above lower limit value, the fine fibrous cellulose-containing slurry can be easily applied. If the coating temperature is equal to or lower than the upper limit value, volatilization of the dispersion medium during the coating can be suppressed.

In the coating step, it is preferable to apply the slurry so that the finished basis weight of the sheet is 10 g / m ² or more and 100 g / m ² or less, preferably 20 g / m ² or more and 50 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 step of obtaining a fiber layer containing fine fibrous cellulose preferably includes a step of drying the fine fibrous cellulose-containing slurry 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 120 ° 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 step of obtaining a fiber layer containing fine fibrous cellulose may include a step of papermaking the fine fibrous cellulose-containing slurry. 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 papermaking process, the fine fibrous cellulose-containing slurry 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 slurry is not specifically limited, 0.05 mass% or more and 5 mass% or less are preferable. When the slurry 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 does not become 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 containing slurry, For example, the method of using the manufacturing apparatus of WO2011 / 013567, etc. are mentioned. This manufacturing apparatus discharges a slurry containing fine fibrous cellulose onto the upper surface of an endless belt, squeezes a dispersion medium from the discharged slurry, generates a web, and dries the web to dry the fiber sheet. And a drying section to produce. 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 composition containing a functional group (A) that forms a covalent bond with a (meth) acryloyl group and a functional group (B) that forms a covalent bond with a hydroxyl group on at least one surface of the fiber layer Apply the object.

Here, as the functional group (A) and the functional group (B), it is preferable to select each of the functional groups described above. Among them, the functional group (A) is preferably at least one selected from a (meth) acryloyl group and a group represented by H ₂ C═CR ² —CH (—OH) —. B) is preferably at least one selected from an isocyanate group, a carbodiimide group, an epoxy group, an alkoxysilyl group, a silanol group, and an oxazoline group.

  The composition containing the functional group (A) and the functional group (B) includes a compound a having at least one functional group (A) and a hydroxyl group, and a compound b having at least two functional groups (B). However, it may contain a compound having at least one functional group (A) and one functional group (B) in one molecule.

The compound a having at least one functional group (A) and one hydroxyl group is preferably a polymer (resin) having a functional group (A). Furthermore, the polymer (resin) having a functional group (A) is an acrylic having at least one selected from a (meth) acryloyl group and a group represented by H ₂ C═CR ² —CH (—OH) —. It is preferably a resin, and is particularly preferably an acrylic resin in which at least one selected from a (meth) acryloyl group and a group represented by H ₂ C═CR ² —CH (—OH) — is graft-polymerized. preferable.

  The compound b having at least two functional groups (B) is preferably an isocyanate compound. Examples of the isocyanate compound include tolylene diisocyanate, xylylene diisocyanate, hexamethylene diisocyanate, and isophorone diisocyanate. The isocyanate compound includes polyisocyanates such as biuret type, nurate type, and adduct type, and such polyisocyanate can also be used. Of these, nurate type polyisocyanate is preferable from the viewpoint of suppressing coloring due to heating and deterioration over time.

  The compound a preferably has at least one functional group (A) and one hydroxyl group, and the hydroxyl group of the compound a first forms a covalent bond with the first functional group (B) of the compound b. A functional group (A) forms a covalent bond with the acryloyl group which the polymer of the acrylic monomer contained in a resin layer has. And the 2nd functional group (B) of the compound b forms a covalent bond with the hydroxyl group which the fine fibrous cellulose contained in a fiber layer has. Thus, the fine fibrous cellulose contained in the fiber layer and the polymer of the acrylic monomer contained in the resin layer are linked by a crosslinked structure in which the functional groups of the compound a and the compound b are covalently bonded.

  In the composition containing the functional group (A) and the functional group (B), the functional group (B) may be contained in an amount of 0.5 mol or more and 5.0 mol or less with respect to 1 mol of the functional group (A). Preferably, 0.5 mol or more and 3.0 mol or less are contained. By setting the molar ratio of the functional group (B) to 1 mol of the functional group (A) within the above range, a cross-linked structure can be formed more effectively, and the interlayer adhesion in the laminate can be further improved. it can.

  The composition containing the functional group (A) and the functional group (B) preferably further contains a polymerization initiator. As a polymerization initiator, the polymerization initiator mentioned above can be illustrated. Especially, it is preferable that a photoinitiator is contained in the composition containing a functional group (A) and a functional group (B). By including a photopolymerization initiator in the composition containing the functional group (A) and the functional group (B), the hardness of the adhesive layer can be further increased by the radiation applied when the resin layer is cured.

  The composition containing the functional group (A) and the functional group (B) may further contain a solvent. Examples of the solvent include esters such as ethyl acetate, butyl acetate, and propyl acetate, ketones such as methyl ethyl ketone, methyl isobutyl, dibutyl ketone, and cyclohexanone, aromatic solvents such as toluene, xylene, and hexane, and organic solvents such as hydrocarbons. Can be mentioned.

  In the step of forming the adhesive layer, a composition containing a functional group (A) that forms a covalent bond with a (meth) acryloyl group and a functional group (B) that forms a covalent bond with a hydroxyl group on at least one surface of the fiber layer Apply the object. As a coating machine that can be used in the coating process, 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.

  After application, it is preferable to provide a polymerization step, and more preferably a thermal polymerization step. In the thermal polymerization step, for example, it is preferable to heat at 70 to 200 ° C. for 0.1 to 10 hours. In the thermal polymerization step, for example, 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) can be applied.

In the polymerization step, a photopolymerization step may be employed, and the thermal polymerization step and the photopolymerization step may be performed simultaneously. In this case, photopolymerization step, the 450nm UV light below or 300 nm, it is preferable to irradiate with 10 mJ / cm ² or more 8000 mJ / cm ² or less.

<Process for forming resin layer>
In the step of forming the resin layer, a resin composition containing at least one selected from an acrylic monomer and a prepolymer of the acrylic monomer is applied.
As an acrylic monomer contained in a resin composition, the acrylic monomer mentioned above can be illustrated. Among them, the acrylic monomer is preferably at least one selected from pentaerythritol tetraacrylate, dipentaerythritol hexaacrylate, and 1,10-decanediol diacrylate. As a prepolymer of an acrylic monomer, the acrylic monomer mentioned above and the copolymer by which the urethane structure and the epoxy structure were copolymerized can be illustrated.

  The resin composition preferably contains a solvent. Examples of the solvent include esters such as ethyl acetate, butyl acetate, and propyl acetate, ketones such as methyl ethyl ketone, methyl isobutyl, dibutyl ketone, and cyclohexanone, aromatic solvents such as toluene, xylene, and hexane, and organic solvents such as hydrocarbons. Can be mentioned.

  The resin composition preferably further contains a polymerization initiator. As a polymerization initiator, the polymerization initiator mentioned above can be illustrated. Especially, it is preferable that a photoinitiator is contained in a resin composition.

  In the step of forming the resin layer, the resin composition is applied on the surface of the adhesive layer formed on at least one surface of the fiber layer. As a coating machine that can be used in the coating process, 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.

  After applying the resin composition, it is preferable to heat at 70 ° C. or higher and 200 ° C. or lower for 0.1 hour or longer and 1 hour or shorter to volatilize the solvent. In the heating step, for example, a method of heating and drying with hot air, infrared rays, far infrared rays or near infrared rays (heating drying method), a method of drying in a vacuum (vacuum drying method) can be employed.

After volatilizing the solvent, it is preferable to provide a step of curing the resin composition. Here, it is preferable to polymerize and cure by radiation irradiation.
The amount of radiation to be irradiated is arbitrary as long as the photopolymerization initiator is in a range that generates radicals. Specifically, it is preferable to irradiate ultraviolet rays of 300 nm to 450 nm in a range of 10 mJ / cm ^{2 to} 1000 mJ / cm ² . Moreover, it is also preferable to irradiate the radiation in two or more times. Specific examples of the lamp used for radiation irradiation include a metal halide lamp, a high pressure mercury lamp, an ultraviolet LED lamp, and an electrodeless mercury lamp.

  In the step of curing the resin composition, photopolymerization and thermal polymerization may be performed simultaneously. In this case, the resin composition is heated and cured in the range of 70 ° C. or higher and 200 ° C. or lower simultaneously with irradiation.

(Use)
Since the laminated body of the present invention is excellent in optical properties, it can be used as a display element, a lighting element, a solar cell or window material, or a panel or substrate for these.
More specifically, the laminate can be used as a flexible display, a touch panel, a liquid crystal display, a plasma display, an organic EL display, a field emission display, a rear projection television display, or the like, or an LED element.

  Moreover, a laminated body can also be used as substrates for solar cells such as silicon-based solar cells and dye-sensitized solar cells. For use as a substrate, a barrier film, ITO, TFT or the like may be laminated.

  Further, the laminate of the present invention includes automobiles, railway vehicles, airplanes, houses, office buildings, factories and other window materials, glazing, interior materials, skins, bumper and other automobiles, railway vehicles, aircraft materials, and PC housings. It can also be used as a structural material for home appliance parts, packaging materials, building materials, civil engineering materials, marine products, and other industrial materials. As a window material, you may laminate | stack films | membranes, such as a fluorine film and a hard-coat film | membrane, and an impact-resistant and light-resistant material as needed.

  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>
[Preparation of phosphorylation reagent]
265 g of sodium dihydrogen phosphate dihydrate and 197 g of disodium hydrogen phosphate were dissolved in 538 g of water to obtain an aqueous solution of a phosphoric acid compound (hereinafter referred to as “phosphorylation reagent”).

[Phosphorylation]
Softwood bleached kraft pulp (manufactured by Oji Holdings Co., Ltd., moisture 50 mass%, Canadian standard freeness (CSF) 700 ml measured according to JIS P 8121) is diluted with ion-exchanged water to a moisture content of 80 mass%. A pulp suspension was obtained. 210 g of the phosphorylating reagent was added to 500 g of this pulp suspension, and the mixture was dried until the mass became constant while being kneaded occasionally with a blow dryer at 105 ° C. (DKM 400, manufactured by Yamato Scientific Co., Ltd.). Subsequently, heat treatment was performed for 1 hour while occasionally kneading with a blow dryer at 150 ° C. to introduce phosphate groups into the cellulose. 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 0.1N 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, washing]
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 atomizer (manufactured by Sugino Machine, Optimizer) to obtain a fine fibrous cellulose dispersion. 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 was 4 nm.

[Sheet]
The concentration was adjusted so that the solid content concentration of the fine fibrous cellulose dispersion 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) was added to 100 parts by mass of the fine fibrous cellulose dispersion. Next, the dispersion was weighed so that the finished basis weight of the sheet was 45.0 g / m ² , developed on 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 fine fibrous cellulose-containing sheet (fiber layer) was obtained. The thickness of the fine fibrous cellulose-containing sheet measured with a stylus thickness meter (Milltron 1202D, manufactured by Marl) is 29.8 μm, and the density calculated by dividing the basis weight by the thickness is 1.51 g / cm ^3. Met.

[Lamination of adhesive layer]
100 parts by mass of an acrylic resin grafted with acryloyl groups (manufactured by Taisei Fine Chemical Co., Ltd., Acryt 8KX-012C), 38 parts by mass of a polyisocyanate compound (manufactured by Asahi Kasei Chemicals Co., Ltd., TPA-100), a radical polymerization initiator (manufactured by BASF, Irgacure 184) 2 parts by mass were mixed to obtain an adhesive composition. Next, the adhesive composition was applied to one surface of the fine fibrous cellulose-containing sheet with a bar coater, and then heated and cured at 100 ° C. for 1 hour to laminate an adhesive layer. Furthermore, the adhesive layer was laminated | stacked on the other surface of the fine fibrous cellulose containing sheet in the same procedure. The thickness of the adhesive layer was 5 μm on one side. By the above procedure, an adhesive layer laminated sheet (A) in which an adhesive layer was laminated on both surfaces of the fine fibrous cellulose-containing sheet was obtained.

[Lamination of resin layer]
A resin composition was obtained by mixing 100 parts by mass of urethane acrylic resin (Arakawa Chemical Industries, Ltd., beam set 575CB) containing 5% by mass of 1-hydroxycyclohexyl phenyl ketone as a photopolymerization initiator and 100 parts by mass of methyl ethyl ketone. Subsequently, after apply | coating the said resin composition to one side of the adhesive layer lamination sheet (A) with a bar coater, it heated at 100 degreeC for 5 minute (s), and the methyl ethyl ketone was volatilized. Furthermore, 500 mJ / cm < ² > of ultraviolet rays were irradiated using the UV conveyor apparatus (Egraphics company make, ECS-4011GX), the resin composition was hardened, and the resin layer was formed. Further, a resin layer was formed on the other surface of the adhesive layer laminated sheet (A) by the same procedure. The thickness of the resin layer was 10 μm on one side. By the above procedure, a laminate in which resin layers were laminated on both surfaces of the adhesive layer laminate sheet (A) was obtained.

<Example 2>
[Lamination of resin layer]
100 parts by mass of acrylic resin (Arakawa Chemical Industry Co., Ltd., Beam Set 710) containing pentaerythritol tetraacrylate as a main component, 100 parts by mass of methyl ethyl ketone, and 5 parts by mass of a radical polymerization initiator (BASF Co., Ltd., Irgacure 184) were mixed. A resin composition was obtained. Next, the resin composition was applied to one surface of the adhesive layer laminated sheet (A) obtained in Example 1 with a bar coater, and then heated at 100 ° C. for 5 minutes to volatilize methyl ethyl ketone. Furthermore, 500 mJ / cm < ² > of ultraviolet rays were irradiated using the UV conveyor apparatus (Egraphics company make, ECS-4011GX), the resin composition was hardened, and the resin layer was formed. Further, a resin layer was formed on the other surface of the adhesive layer laminated sheet (A) by the same procedure. The thickness of the resin layer was 10 μm on one side. By the above procedure, a laminate in which resin layers were laminated on both surfaces of the adhesive layer laminate sheet (A) was obtained.

<Example 3>
[Lamination of resin layer]
100 parts by mass of an acrylic resin (made by Arakawa Chemical Industry Co., Ltd., Beam Set 710) having 100% of dipentaerythritol hexaacrylate as a main component, 100 parts by mass of methyl ethyl ketone, and 5 parts by mass of a radical polymerization initiator (manufactured by BASF, Irgacure 184) are mixed. Thus, a resin composition was obtained. Next, the resin composition was applied to one surface of the adhesive layer laminated sheet (A) obtained in Example 1 with a bar coater, and then heated at 100 ° C. for 5 minutes to volatilize methyl ethyl ketone. Furthermore, 500 mJ / cm < ² > of ultraviolet rays were irradiated using the UV conveyor apparatus (Egraphics company make, ECS-4011GX), the resin composition was hardened, and the resin layer was formed. Further, a resin layer was formed on the other surface of the adhesive layer laminated sheet (A) by the same procedure. The thickness of the resin layer was 10 μm on one side. By the above procedure, a laminate in which resin layers were laminated on both surfaces of the adhesive layer laminate sheet (A) was obtained.

<Example 4>
[Creation of glass cell for resin layer molding]
Two adhesive layer laminated sheets (A) obtained in Example 1 were cut into dimensions of 120 mm in length and 55 mm in width. Next, a gap of 95 mm in length, 40 mm in width, and 2 mm in thickness is provided in the center of silicon rubber having a length of 125 mm, a width of 60 mm, and a thickness of 2 mm to form a spacer, and a glass plate is arranged on the outer periphery. The adhesive layer laminated sheet (A) was inserted along the inner periphery of the silicon rubber. In addition, the opening part of width 5mm for inject | pouring the resin composition mentioned later into a space | gap was provided in the side part of the silicon rubber used as the spacer and the adhesive layer laminated sheet (A). In addition, two glass sheets with a length of 125 mm, a width of 60 mm, and a thickness of 3 mm are sandwiched between the two adhesive layer laminated sheets (A) from the top and bottom, and two points on the left and right and one point on the top and bottom are fixed with a double clip and sealed did. FIG. 5 is a diagram of the resin layer molding glass cell 200 produced as described above, as viewed from above, and is a schematic diagram of the resin layer molding glass cell with the upper glass plate removed. As shown in FIG. 5, in the glass cell 200 for resin layer molding, the adhesive layer laminated sheet (A) 130, the silicon rubber 120, and the glass plate 110 are disposed around the inner space.

[Molding of resin layer]
Mixing 100 parts by mass of an acrylic resin (Shin-Nakamura Chemical Co., Ltd., A-DOD-N) with 3 parts by mass of a radical polymerization initiator (BASF Co., Irgacure 184) containing 1,10-decanediol diacrylate as a main component Thus, a resin composition was obtained. Next, the resin composition was injected into the internal space of the glass cell 200 for resin layer formation using a micropipette from the opening of the spacer. Furthermore, silicon rubber is inserted and sealed in the opening, and the resin composition is cured by irradiating UV rays of 300 mJ / cm ² 20 times using a UV conveyor device (ECS-4011GX, manufactured by Eye Graphics Co., Ltd.). I let you. Thereafter, the glass plate and the silicon rubber were removed, and a laminate in which fine fibrous cellulose-containing sheets (fiber layers) were laminated on both sides of a 1920 μm thick resin layer via an adhesive layer was obtained.

<Comparative Example 1>
In Example 1, the adhesive layer was not laminated. Other procedures were the same as in Example 1 to obtain a laminate.

<Comparative example 2>
In Example 2, the adhesive layer was not laminated. Other procedures were the same as in Example 2 to obtain a laminate.

<Comparative Example 3>
In Example 3, the adhesion layer was not laminated. Other procedures were the same as in Example 3 to obtain a laminate.

<Comparative example 4>
[Lamination of adhesive layer]
A polyester resin UV coat anchor agent (Arakawa Chemical Industry Co., Ltd., Aracoat AP2510) 76 parts by mass, a curing agent (Arakawa Chemical Industry Co., Ltd., Alacoat CL2502) 10 parts by mass and methyl ethyl ketone 14 parts by mass were mixed to prepare an adhesive composition. Obtained. Next, the adhesive composition was applied to one surface of the fine fibrous cellulose-containing sheet (fiber layer) obtained in Example 1 with a bar coater, and then heated and cured at 100 ° C. for 3 minutes to be bonded. Layers were laminated. Furthermore, the adhesive layer was laminated | stacked on the other surface of the fine fibrous cellulose containing sheet in the same procedure. The thickness of the adhesive layer was 5 μm on one side. By the above procedure, an adhesive layer laminated sheet (B) in which an adhesive layer was laminated on both surfaces of the fine fibrous cellulose-containing sheet was obtained.

[Lamination of resin layer]
A resin layer was laminated on the adhesive layer laminated sheet (B) in the same procedure as in Example 1 to obtain a laminate.

<Comparative Example 5>
A resin layer was laminated on the adhesive layer laminated sheet (B) obtained in Comparative Example 4 in the same procedure as in Example 2 to obtain a laminate.

<Comparative Example 6>
A resin layer was laminated on the adhesive layer laminated sheet (B) obtained in Comparative Example 4 in the same procedure as in Example 3 to obtain a laminate.

<Comparative Example 7>
[Lamination of adhesive layer]
An adhesive composition was obtained by mixing 26 parts by mass of a silsesquioxane resin (Arakawa Chemical Industries, Composeran SQ107), 14 parts by mass of a curing agent (HBSQ202, manufactured by Arakawa Chemical Industries, Ltd.) and 60 parts by mass of isopropyl alcohol. . Next, the adhesive composition was applied to one surface of the fine fibrous cellulose-containing sheet obtained in Example 1 with a bar coater, and then heated at 100 ° C. for 5 minutes to volatilize isopropyl alcohol. Furthermore, 300 mJ / cm < ² > ultraviolet-ray was irradiated using the UV conveyor apparatus (Egraphics company make, ECS-4011GX), the adhesive composition was hardened, and the contact bonding layer was laminated | stacked. Furthermore, the adhesive layer was laminated | stacked on the other surface of the fine fibrous cellulose containing sheet in the same procedure. The thickness of the adhesive layer was 5 μm on one side. By the above procedure, an adhesive layer laminated sheet (C) in which an adhesive layer was laminated on both surfaces of the fine fibrous cellulose-containing sheet was obtained.

[Lamination of resin layer]
A resin layer was laminated on the adhesive layer laminated sheet (C) in the same procedure as in Example 1 to obtain a laminate.

<Comparative Example 8>
A resin layer was laminated on the adhesive layer laminated sheet (B) obtained in Comparative Example 7 in the same procedure as in Example 2 to obtain a laminate.

<Comparative Example 9>
A resin layer was laminated on the adhesive layer laminated sheet (B) obtained in Comparative Example 7 in the same procedure as in Example 3 to obtain a laminate.

<Evaluation>
The laminates obtained in Examples and Comparative Examples were measured by the following method.

[Tensile modulus]
Based on JIS P8113, the tensile modulus at a temperature of 23 ° C. and a relative humidity of 50% was measured using a tensile tester (manufactured by L & W, Tensile Tester CODE SE-064).

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

[Initial adhesion]
In accordance with JIS K 5400, 100 pieces of 1 mm ² crosscuts are put on the fiber layer side surface of the laminate, cellophane tape (manufactured by Nichiban Co., Ltd.) is pasted thereon, and pressed with a load of 1.5 kg / cm ^2. After that, it was peeled in the 90 ° direction. The adhesiveness between the resin layer and the fiber layer (fine fibrous cellulose-containing sheet) was evaluated based on the number of cells separated.

[Adhesion after accelerated test]
The laminate was placed in a thermo-hygrostat (manufactured by Tokyo Science Instruments Co., Ltd., KCL-2000) at a temperature of 85 ° C. and a relative humidity of 85%, and allowed to stand for 240 hours. Thereafter, the laminate was placed in an environment having a temperature of 23 ° C. and a relative humidity of 50% for 1 hour. Thereafter, in accordance with JIS K 5400, 100 pieces of 1 mm ² crosscuts were put on the surface of the laminated body on the fiber layer side, cellophane tape (manufactured by Nichiban Co., Ltd.) was pasted thereon, and a load of 1.5 kg / cm ² After pressing, it was peeled away in the 90 ° direction. The adhesiveness between the resin layer and the fiber layer (fine fibrous cellulose-containing sheet) was evaluated based on the number of cells separated.

As is apparent from Table 1, in Examples 1 to 4, the adhesive layer contains an acryloyl group as a functional group that forms a covalent bond with a (meth) acryloyl group, and an isocyanate group as a functional group that forms a covalent bond with a hydroxyl group. A laminate having high tensile elastic modulus, high total light transmittance, good initial adhesion, and good adhesion after the acceleration test was obtained. This is because a covalent bond is formed between the isocyanate group of the adhesive layer and the hydroxyl group of the fine fibrous cellulose-containing sheet, and between the acryloyl group of the adhesive layer and the acryloyl group of the resin layer, and the isocyanate group of the adhesive layer. Since a covalent bond is formed between the acryloyl group of the adhesive layer and the adhesive layer, it is considered that strong adhesion was obtained.
On the other hand, in Comparative Examples 1 to 3 in which the adhesive layer was not laminated, both the initial adhesion and the adhesion after the acceleration test were low. In Comparative Examples 4 to 6 using a polyester resin as an adhesive layer and Comparative Examples 7 to 9 using a silsesquioxane-based resin, the initial adhesion was relatively good, but the adhesion after the acceleration test. As a result, there are concerns about practical problems in applications where use under severe conditions is expected.

(Production example)
<Example 5 (Production Example 1 of inorganic film laminate)>
Using the laminates obtained in Examples 1 to 4, an inorganic film laminate can be produced by the following procedure.
An aluminum oxide film is formed on the stacked body using an atomic layer deposition apparatus (PUNSON, SUNALE R-100B). 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 laminate in which an aluminum oxide film having a thickness of 30 nm is laminated on both surfaces of the laminate is obtained.

<Example 6 (Production Example 2 of inorganic film laminate)>
Using the laminates obtained in Examples 1 to 4, an inorganic film laminate can be produced by the following procedure.
A silicon oxynitride film is formed on the stacked body using a plasma CVD apparatus (ICP-CVD roll-to-roll apparatus manufactured by Cellvac). The laminate is bonded to the upper surface of the 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 an inorganic film laminate in which a silicon oxynitride film having a thickness of 500 nm is laminated on one side of the laminate. Furthermore, an inorganic film laminated body in which a silicon oxynitride film having a thickness of 500 nm is laminated on both surfaces of the laminated body can also be obtained by performing film formation on the opposite surface in the same procedure.

DESCRIPTION OF SYMBOLS 10 Fiber layer 20 Adhesion layer 30 Resin layer 100 Laminate body 110 Glass plate 120 Silicon rubber 130 Adhesion layer lamination sheet (A)
150 Opening 200 Glass Cell for Resin Layer Molding

Claims (18)

It has a fiber layer, an adhesive layer, and a resin layer in this order,
The fiber layer includes fine fibrous cellulose having a fiber width of 1000 nm or less,
The adhesive layer includes a functional group (A) that forms a covalent bond with a (meth) acryloyl group, and further includes a functional group (B) that forms a covalent bond with a hydroxyl group and a hydrolyzable group of the functional group (B). Including at least one selected,
The resin layer is a laminate including a polymer of acrylic monomers. _2. The laminate according to claim 1, wherein the functional group (A) is at least one selected from a (meth) acryloyl group and a group represented by H ₂ C═CR ² —CH (—OH) —. (Wherein R ² represents a hydrogen atom or a methyl group).   The laminate according to claim 1, wherein the functional group (B) is at least one selected from an isocyanate group, a carbodiimide group, an epoxy group, an alkoxysilyl group, a silanol group, and an oxazoline group.   The laminate according to any one of claims 1 to 3, wherein the adhesive layer includes a polymer having the functional group (A) and a compound having the functional group (B).   After the laminate is placed for 240 hours under conditions of a temperature of 85 ° C. and a relative humidity of 85%, the number of peels in the 100 masses of the fiber layer is 10 or less when a cross-cut test according to JIS K 5400 is performed. Item 5. The laminate according to any one of Items 1 to 4. Laminate according to any one of claims 1 to 5 density of the fiber layer is 1.0 g / cm ³ or more.   The laminate according to any one of claims 1 to 6, wherein the tensile elastic modulus is 5 GPa or more.   The laminate according to any one of claims 1 to 7, wherein the total light transmittance is 85% or more.   The laminate according to any one of claims 1 to 8, wherein the adhesive layer further contains a polymerization initiator.   The said resin layer is a laminated body of any one of Claims 1-9 which further contain a polymerization initiator.   The laminate according to any one of claims 1 to 10, wherein the adhesive layer is a coated adhesive layer, and the resin layer is a coated resin layer.   The adhesive layer is applied by applying a composition containing a resin having the functional group (A) and a hydroxyl group and a compound having at least two functional groups (B) on at least one surface of the fiber layer. The laminate according to any one of claims 1 to 11, which is produced by forming the resin layer by applying and forming a resin composition containing an acrylic monomer on the adhesive layer. Obtaining a fiber layer containing fine fibrous cellulose having a fiber width of 1000 nm or less;
A composition containing a functional group (A) that forms a covalent bond with a (meth) acryloyl group and a functional group (B) that forms a covalent bond with a hydroxyl group is applied to at least one surface of the fiber layer, and an adhesive layer Forming a step;
Applying a resin composition containing an acrylic monomer to form a resin layer. The functional group (A) is at least one selected from a (meth) acryloyl group or a group represented by H ₂ C═CR ² —CH (—OH) —. the method for producing the laminate (wherein, R ² represents a hydrogen atom or a methyl group).   The method for producing a laminate according to claim 13 or 14, wherein the functional group (B) is at least one selected from an isocyanate group, a carbodiimide group, an epoxy group, an alkoxysilyl group, a silanol group, and an oxazoline group.   The composition containing the functional group (A) and the functional group (B) comprises the resin having the functional group (A) and a hydroxyl group, and a compound having at least two functional groups (B). The manufacturing method of the laminated body of any one of -15.   The method for producing a laminate according to any one of claims 13 to 16, wherein the composition containing the functional group (A) and the functional group (B) further contains a polymerization initiator.   The manufacturing method of the laminated body of any one of Claims 13-17 in which the polymerization initiator is further contained in the said resin composition.

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