JP2017057116A - Sol liquid and method for producing the same, method for producing laminate film, laminate film, optical member, and image display device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a silica porous particle sol liquid that has a high void ratio (porosity) and improved production efficiency, and can form a void layer having a good appearance.SOLUTION: A sol liquid has dispersoid, and dispersion medium, the dispersion medium comprising organic solvent with a boiling point of 70°C or more and less than 180°C, and saturation vapor pressure at 20°C of 15 kPa or less.SELECTED DRAWING: None

Description

  The present invention relates to a sol solution and a method for producing the same, a method for producing a laminated film, a laminated film, an optical member, and an image display device.

  Various studies have been made on silica porous particle sol solutions capable of forming a void structure using a silica compound material (silicon compound material) as a raw material. As a common point to them, after the silica compound is once gelled, a pulverized sol solution prepared by pulverizing the gelled silica compound is prepared, and a void structure is formed by coating (coating). That is the point. However, when trying to obtain a higher porosity, there is a problem that the film strength of the silanol porous body is remarkably lowered, and it is difficult to easily obtain the silanol porous body industrially. As an example of achieving both high porosity and strength, there is an application example to a lens antireflection layer (see, for example, Patent Documents 1 to 4). In this method, after a void layer is formed on the lens, a high temperature of 150 ° C. or higher is baked for a long time. However, since a gel using tetraethoxysilane (TEOS) as a raw material is inferior in flexibility, There was a problem that a porous body could not be formed on a soft substrate. On the other hand, there is an application example of a void layer in which no firing treatment is performed (for example, see Non-Patent Document 1). However, in this method, the silanol pulverized sol still contains a large amount of residual silanol groups, and no firing treatment is performed after the formation of the void layer, so that the resulting porous body has poor film strength and cannot impart impact resistance. There was a problem.

  In order to solve such a problem, an attempt has been made to develop a film that replaces an air layer formed by a gap between members.

JP 2006-297329 A JP 2006-221144 A JP 2006-011175 A JP 2008-040171 A

J. et al. Mater. Chem. , 2011, 21, 14830-14837

  However, when a high void film is formed from a sol solution using a highly volatile solvent with an emphasis on production efficiency, the solvent volatilizes and the silica compound particles easily precipitate. May be inferior. On the other hand, when a high void film is formed from a sol solution using a solvent having a high boiling point and a low volatility, the solvent is difficult to volatilize, which may reduce the production efficiency. Similar problems exist not only in porous particles of silica compounds but also in void layers (high void membranes) formed of other substances.

  Accordingly, an object of the present invention is to provide a sol solution that has a high porosity (porosity), improves production efficiency, and can form a void layer having an excellent appearance.

In order to achieve the above object, the sol solution of the present invention comprises:
A sol solution containing a dispersoid and a dispersion medium,
The dispersion medium includes an organic solvent having a boiling point of 70 ° C. or higher and lower than 180 ° C. and a saturated vapor pressure at 20 ° C. of 15 kPa or lower.

The method for producing a sol liquid of the present invention is a method for producing the sol liquid of the present invention,
It includes a mixing step of mixing the dispersoid and the dispersion medium.

  The method for producing a laminated film of the present invention is a method for producing a laminated film in which a void layer is laminated on a resin film, the coating step of coating the sol solution of the present invention on the resin film, And a drying step of drying the processed sol solution.

  The laminated film of the present invention is produced by the method for producing a laminated film of the present invention.

  The optical member of the present invention includes the laminated film of the present invention.

  The image display device of the present invention includes the optical member of the present invention.

  The manufacturing method of the optical member containing the laminated | multilayer film of this invention includes the process of manufacturing the said laminated | multilayer film with the manufacturing method of the laminated | multilayer film of the said this invention.

  The manufacturing method of the image display apparatus containing the optical member of this invention includes the process of manufacturing the said optical member with the manufacturing method of the optical member containing the laminated | multilayer film of the said invention.

  The present invention can provide, for example, a sol liquid that has a high porosity (porosity), improves production efficiency, and can form a void layer having an excellent appearance.

FIG. 1 is a process cross-sectional view schematically showing an example of a method for forming a void layer 20 on a substrate 10 using the sol solution of the present invention. FIG. 2 is a diagram schematically showing a part of a process for producing a void layer using the sol solution of the present invention and an example of an apparatus used therefor. FIG. 3 is a diagram schematically showing a part of a process for producing a void layer using the sol solution of the present invention and another example of an apparatus used therefor. FIG. 4 is a process cross-sectional view schematically showing another example of a method for forming a void layer on a substrate in the present invention. FIG. 5 is a diagram schematically showing a part of a process for producing a void layer using the sol solution of the present invention and still another example of an apparatus used therefor. FIG. 6 is a diagram schematically showing a part of a process for producing a void layer using the sol solution of the present invention and still another example of an apparatus used therefor. FIG. 7 is a process cross-sectional view schematically showing still another example of a method for forming a void layer on a substrate in the present invention. FIG. 8 is a diagram schematically showing a part of a process for producing a void layer using the sol solution of the present invention and still another example of an apparatus used therefor. FIG. 9 is a diagram schematically showing a part of a process for producing a void layer using the sol solution of the present invention and still another example of an apparatus used therefor.

  Hereinafter, the present invention will be described more specifically with reference to examples. However, the present invention is not limited or restricted by the following description.

  The sol solution of the present invention may be capable of obtaining a high-porosity film or a high-porosity film roll having a porosity of 40% or more, for example, by drying by heating at a temperature of 150 ° C. or less. Moreover, this invention is a manufacturing method of the high porosity film | membrane (void layer) or the high porosity film | membrane roll with a porosity of 40% or more including the process of heat-drying the sol liquid of the said invention at the temperature of 150 degrees C or less. There may be. In addition, the said high porosity film | membrane roll means the said high porosity film | membrane (void | gap layer) which is roll shape.

  In the sol solution of the present invention, the constituent unit constituting the dispersoid may have a structure having at least one of a particle shape, a fiber shape, and a flat plate shape, for example. The particulate and flat structural units may be made of an inorganic substance, for example. In addition, the constituent element of the particulate structural unit may include at least one element selected from the group consisting of Si, Mg, Al, Ti, Zn, and Zr, for example. The structure (structural unit) that forms the particles may be a real particle or a hollow particle, and specifically includes silicone particles, silicone particles having fine pores, silica hollow nanoparticles, silica hollow nanoballoons, and the like. The fibrous structural unit is, for example, a nanofiber having a diameter of nanometer, and specifically includes cellulose nanofiber, alumina nanofiber, and the like. Examples of the plate-like structural unit include nanoclay, specifically, nano-sized bentonite (for example, Kunipia F [trade name]) and the like. The fibrous structural unit is not particularly limited, but for example, from the group consisting of carbon nanofiber, cellulose nanofiber, alumina nanofiber, chitin nanofiber, chitosan nanofiber, polymer nanofiber, glass nanofiber, and silica nanofiber. It may be at least one fibrous material selected.

  In the laminated film of the present invention, the void layer laminated on the resin film (hereinafter sometimes referred to as “the void layer of the present invention”) is, for example, one type or plural types forming a fine void structure. These structural units may include, for example, a part that is directly or indirectly chemically bonded. The structural unit in the void layer may be the same as the structural unit constituting the dispersoid in the sol liquid of the present invention, for example. Further, the chemical bond between the structural units may be, for example, a bond through a catalytic action. Further, for example, only a part of the one type or plural types of structural units may be chemically bonded. Specifically, for example, even if the structural units are in contact with each other, there may be a portion that is not chemically bonded. Further, in the present invention, the structural units are “indirectly bonded” means that the structural units are bonded to each other through a small amount of a binder component equal to or less than the structural unit amount. The structural units are “directly bonded” means that the structural units are directly bonded without using a binder component or the like. In the void structure film of the present invention, for example, the bond between the structural units may include a hydrogen bond, a covalent bond, or an electrostatic interaction.

  Hereinafter, the case where the constituent unit constituting the dispersoid is porous particles in the sol liquid of the present invention (that is, the case where the sol liquid of the present invention is a porous particle sol liquid) will be described. Furthermore, among them, the porous particles in the porous particle sol liquid of the present invention are mainly silica porous particles (that is, the porous particle sol liquid of the present invention is a silica porous particle sol liquid). ). However, as described above, in the sol solution of the present invention, the structural unit constituting the dispersoid is not limited to porous particles or silica, and is arbitrary.

  The sol liquid of the present invention (for example, a porous particle sol liquid, typically a silica porous particle sol liquid) has, for example, a volume average particle diameter of a constituent unit of the sol (for example, silica porous particles). 0.05 to 2.00 μm. In the present invention, the shape of “particles” (for example, particles of the pulverized product) is not particularly limited, and may be, for example, spherical, but may be other shapes. In the present invention, the particles of the pulverized product may be, for example, sol-gel bead-like particles, nanoparticles (hollow nanosilica / nanoballoon particles), nanofibers, or the like.

  In the sol liquid of the present invention, the dispersion medium contains, for example, a dispersion containing 20 to 100% by mass of the organic solvent having a boiling point of 70 ° C. or more and less than 180 ° C. and a saturated vapor pressure at 20 ° C. of 15 kPa or less. It is a medium.

  In the silica porous particle sol solution of the present invention, the silica porous particle is, for example, a pulverized product of a gel silicon compound obtained from a silicon compound containing at least a trifunctional or lower saturated bond functional group. The pulverized product contains, for example, residual silanol groups, and the silica porous particle sol solution is, for example, a sol solution for chemically bonding the pulverized products.

  In the silica porous particle sol solution of the present invention, the silicon compound is, for example, a compound represented by the following formula (2).

  The porous silica particle sol solution of the present invention includes, for example, a catalyst for chemically bonding the pulverized products.

  In the method for producing a silica porous particle sol solution of the present invention, the silica porous particle sol solution is, for example, the silica porous particle sol solution of the present invention. The method for producing the silica porous particle sol liquid includes, for example, a pulverization step of pulverizing the gel silicon compound in a solvent, and the pulverized product obtained by the pulverization step is used in the mixing step.

  The method for producing a silica porous particle sol solution of the present invention includes, for example, a gelation step in which the silicon compound is gelled in a solvent to produce the gel silicon compound. In this case, in the pulverization step, the gelled silicon compound obtained by the gelation step is used.

  The method for producing a porous silica particle sol solution of the present invention includes, for example, an aging step of aging the gel silicon compound in a solvent. In this case, the gelled silicon compound after the aging step is used in the gelation step. In the aging step, for example, the gel silicon compound is aged by incubating in the solvent at 30 ° C. or higher.

  In the method for producing the laminated film, for example, in the drying step, the coated sol solution of the present invention (for example, the silica porous particle sol solution) is heated and dried at a temperature of 150 ° C. or lower.

  In the method for producing the laminated film, the void ratio of the void layer is, for example, 40% by volume or more.

  In the method for manufacturing the laminated film, the resin film is, for example, a long resin film. In this case, for example, the coating process and the drying process are continuously performed on the long resin film.

  In the method for producing a laminated film, the laminated film is, for example, a wound laminated film roll. In this case, the manufacturing method of the said laminated | multilayer film further includes the winding process which winds the said laminated | multilayer film by which the said space | gap layer was laminated | stacked on the said resin film, and makes it the said laminated | multilayer film roll.

  Hereinafter, the present invention will be described with further examples.

  As described above, the sol liquid of the present invention is a sol liquid containing a dispersoid and a dispersion medium, and the dispersion medium has a boiling point of 70 ° C. or higher and lower than 180 ° C., and a saturated vapor at 20 ° C. An organic solvent having a pressure of 15 kPa or less is included.

  As a result of extensive studies, the present inventors have found that the dispersion medium contained in the sol liquid has an organic solvent having a boiling point of 70 ° C. or higher and lower than 180 ° C. and a saturated vapor pressure at 20 ° C. of 15 kPa or lower. It has been found that by using the sol solution, it is possible to form a void layer having a high porosity (porosity), improving production efficiency, and having an excellent appearance. The reason (mechanism) is unknown, but is estimated from the following explanation, for example.

  In the production of the laminated film, for example, a sol solution as a raw material for the void layer is applied by a lip coater or the like (coating process). Next, for example, the coated sol solution is dried for the purpose of removing the dispersion medium contained in the sol solution (drying step). Here, first, when the dispersion medium contained in the sol liquid is a low-volatile solvent, in the coating process, in order to apply an inorganic sol liquid that is not a dissolved substance, for example, Since inorganic substances are likely to precipitate on the lip, the appearance of the coated film may be inferior. Therefore, the present inventors have found that a solvent having a low saturated vapor pressure is required as the dispersion medium in order to make it less likely to volatilize around room temperature. On the other hand, the present inventors can suppress that the dispersion medium remains if the dispersion medium has a low boiling point in the drying step, and that the low refractive index is good. I found it. Based on the above findings, the present inventors have conducted extensive studies, and as a result, the dispersion medium contained in the sol liquid has a boiling point of 70 ° C. or higher and lower than 180 ° C. and a saturated vapor pressure at 20 ° C. It has been found that by including an organic solvent of 15 kPa or less, it is possible to produce a void layer that has a high porosity (porosity), improves production efficiency, and can form a void layer having an excellent appearance. . However, this reason (mechanism) is an example of a presumed reason (mechanism), and does not limit the present invention.

[1. Sol solution and production method thereof]
Hereinafter, the sol liquid of the present invention and the method for producing the sol liquid will be described mainly using an example in which the dispersoid is a porous silica particle. However, as described above, in the porous particle sol liquid of the present invention, the dispersoid material may be any material other than silica.

  The porous silica particle sol solution of the present invention contains porous silica particles that are a dispersoid and a dispersion medium. The dispersion medium includes an organic solvent having a boiling point of 70 ° C. or higher and lower than 180 ° C. and a saturated vapor pressure at 20 ° C. of 15 kPa or lower. The silica porous particle is, for example, a pulverized product of a gel-like silicon compound obtained from a silicon compound containing at least a trifunctional or lower saturated bond functional group, and the pulverized product contains, for example, residual silanol groups, The silica porous particle sol solution is, for example, a sol solution for chemically bonding the pulverized products. The above-mentioned “including a saturated bond functional group having 3 or less functional groups” means that the silicon compound has 3 or less functional groups, and these functional groups are saturatedly bonded to silicon (Si). Means.

  The method for producing a silica porous particle sol solution of the present invention includes a mixing step of mixing the silica porous particles and the dispersion medium.

  As described later, the silica porous particle sol solution of the present invention can be used for the production of a silicone porous body (void layer) having the same function as the air layer (for example, low refractive index). Specifically, the silica porous particle sol solution obtained by the production method of the present invention contains, for example, a pulverized product of the gel-like silicon compound as the silica porous particle, and the pulverized product is an unground product. The three-dimensional structure of the gel silicon compound is destroyed, and a new three-dimensional structure different from the uncrushed gel silicon compound can be formed. For this reason, for example, a coating film (silicone porous body precursor) formed using the silica porous particle sol solution cannot be obtained in a layer formed using the unground silica gel compound. It becomes a layer in which a simple pore structure (new void structure) is formed. Thereby, the layer can exhibit the same function as the air layer (for example, the same low refractive index). The silica porous particle sol solution of the present invention contains, for example, the organic solvent having a boiling point of 70 ° C. or higher and lower than 180 ° C. and a saturated vapor pressure at 20 ° C. of 15 kPa or less as a dispersion medium. The appearance of the coating film (silicone porous body precursor) can be improved. Thereby, the formed silicone porous body can have a high porosity (porosity), improve the production efficiency, and form a void layer having an excellent appearance. For this reason, according to this invention, a silicone porous body can be easily and simply provided to various objects. The silica porous particle sol solution obtained by the production method of the present invention is very useful in the production of the porous structure (for example, void layer) that can be used as an alternative to the air layer, for example. Further, in the case of the air layer, for example, it is necessary to form an air layer between the members by stacking the members with a gap provided therebetween via a spacer or the like. However, the silicone porous body formed using the silica porous particle sol solution of the present invention can exhibit the same function as the air layer only by disposing it at a target site. Therefore, as described above, functions similar to the air layer can be imparted to various objects more easily and simply than forming the air layer. Specifically, the porous structure (for example, a void layer) can be used as, for example, a heat insulating material, a sound absorbing material, a regenerative medical scaffolding material, a dew condensation preventing material, an optical member, an image display device, etc., instead of an air layer. .

  The sol liquid (for example, silica porous particle sol liquid) of the present invention can also be referred to as, for example, a sol liquid for forming a void layer (for example, a porous silicon body) or a sol liquid for forming a low refractive layer.

[Silica porous particles]
In the silica porous particle sol solution of the present invention, the volume average particle diameter of the silica porous particles is not particularly limited, and the lower limit thereof is, for example, 0.05 μm or more, 0.10 μm or more, 0.20 μm or more, 0 The upper limit is, for example, 2.00 μm or less, 1.50 μm or less, 1.00 μm or less, and the ranges thereof are, for example, 0.05 μm to 2.00 μm, 0.20 μm to 1.50 μm. 0.40 μm to 1.00 μm. The volume average particle diameter indicates a particle size variation of the silica porous particles in the silica porous particle sol liquid of the present invention. The volume average particle diameter is measured by, for example, a particle size distribution evaluation apparatus such as a dynamic light scattering method and a laser diffraction method, and an electron microscope such as a scanning electron microscope (SEM) and a transmission electron microscope (TEM). Can do.

  In the silica porous particle sol solution of the present invention, the particle size distribution of the silica porous particles is not particularly limited. For example, particles having a particle diameter of 0.4 μm to 1 μm are 50 to 99.9% by weight, 80%. ˜99.8% by weight, 90˜99.7% by weight, or particles having a particle size of 1 μm to 2 μm are 0.1 to 50% by weight, 0.2 to 20% by weight, 0.3 to 10% by weight. %. The particle size distribution indicates the particle size variation of the silica porous particles in the silica porous particle sol solution of the present invention. The particle size distribution can be measured by, for example, a particle size distribution evaluation apparatus or an electron microscope.

  In the silica porous particle sol solution of the present invention, the silica porous particles are, for example, a pulverized product of a gel silicon compound obtained from a silicon compound containing at least a trifunctional or lower saturated bond functional group as described above. The pulverized product contains residual silanol groups. The silicon compound is, for example, a compound represented by the following formula (2).

In the formula (2), for example, X is 2, 3 or 4,
R ¹ and R ² are each a linear or branched alkyl group,
R ¹ and R ² may be the same or different,
R ^{1 s} may be the same as or different from each other when X is 2.
R ² may be the same as or different from each other.

Wherein X and ^{R 1} are, for example, the same as X and ^{R 1} in the formula (1). In addition, the ^{R 2} is, for example, can be exemplified for ^{R 1} is incorporated in the formula (1) described later.

  X is preferably 2 or 3.

Specific examples of the silicon compound represented by the formula (2) include a compound represented by the following formula (2 ′) in which X is 3. In the following formula (2 ′), R ¹ and R ² are the same as those in the formula (2), respectively. When R ¹ and R ² are methyl groups, the silicon compound is trimethoxy (methyl) silane (hereinafter also referred to as “MTMS”).

  In the silica porous particle sol solution of the present invention, the concentration of the silica porous particles in the dispersion medium is not particularly limited, and is, for example, 0.3 to 15 wt%, 0.5 to 10 wt%, 1.0 ~ 8% by weight. If the concentration of the silica porous particles is too high, for example, the fluidity of the sol solution is significantly lowered, and there is a possibility that aggregates and coating streaks are generated during coating. On the other hand, if the concentration of the porous silica particles is too low, for example, not only does it take a considerable amount of time to dry the dispersion medium, but also the residual solvent immediately after drying increases, so the porosity may decrease. There is sex.

  The physical properties of the silica porous particle sol solution of the present invention are not particularly limited. The shear viscosity of the silica porous particle sol liquid is, for example, a viscosity of 100 cPa · s or less, a viscosity of 10 cPa · s or less, and a viscosity of 1 cPa · s or less at a shear rate of 10001 / s. If the shear viscosity is too high, for example, coating streaks may occur, and problems such as a decrease in the transfer rate of gravure coating may be observed. On the other hand, when the shear viscosity is too low, for example, the wet coating thickness at the time of coating cannot be increased, and a desired thickness may not be obtained after drying.

[Dispersion medium]
In the sol liquid of the present invention (for example, a porous particle sol liquid, typically a silica porous particle sol liquid), the dispersion medium (hereinafter also referred to as “coating solvent”) is as described above. The organic solvent whose boiling point is 70 degreeC or more and less than 180 degreeC and whose saturated vapor pressure in 20 degreeC is 15 kPa or less is included.

  Examples of the organic solvent include carbon tetrachloride, 1,2-dichloroethane, 1,1,2,2-tetrachloroethane, trichloroethylene, isobutyl alcohol, isopropyl alcohol, isopentyl alcohol, 1-pentyl alcohol (pentanol), Ethyl alcohol (ethanol), ethylene glycol monoethyl ether, ethylene glycol monoethyl ether acetate, ethylene glycol mono-normal-butyl ether, ethylene glycol monomethyl ether, xylene, cresol, chlorobenzene, isobutyl acetate, isopropyl acetate, isopentyl acetate, ethyl acetate, Normal-butyl acetate, normal-propyl acetate, normal-pentyl acetate, cyclohexanol, cyclohexanone, 1,4-dioxane N, N-dimethylformamide, styrene, tetrachloroethylene, 1,1,1-trichloroethane, toluene, 1-butanol, 2-butanol, methyl isobutyl ketone, methyl ethyl ketone, methyl cyclohexanol, methyl cyclohexanone, methyl normal butyl ketone, isopent And tanol. The dispersion medium may contain an appropriate amount of a perfluoro-based surfactant, a silicon-based surfactant or the like that lowers the surface tension.

  In the sol solution of the present invention, the dispersion medium contains, for example, 20 to 100% by mass, 25 to 95% by mass, or 30 to 90% by mass of the organic solvent. In the present invention, the dispersion medium may contain another solvent as the dispersion medium as long as it contains the organic solvent.

  The sol liquid of the present invention can continuously form a void layer having a film strength of a certain level or more by performing chemical cross-linking by a bonding step after coating and drying on a substrate, for example. is there. The “sol” in the present invention refers to a pulverized three-dimensional structure of a gel, whereby the pulverized product (for example, nano three-dimensional silica porous particles retaining a part of a void structure) is dispersed in a dispersion medium. A state in which it is dispersed and exhibits fluidity.

[catalyst]
In the silica porous particle sol solution of the present invention, when the silica porous particle is a pulverized product of a gel-like silicon compound obtained from a silicon compound containing at least a trifunctional or lower saturated bond functional group, It is preferable that the catalyst for chemically couple | bonding is included. The addition amount of the catalyst is 0.01 to 20% by weight, 0.05 to 10% by weight, and 0.1 to 5% by weight with respect to the solid content in the gel.

  The catalyst may be, for example, a catalyst that promotes cross-linking between the pulverized products. As a chemical reaction for chemically bonding the pulverized materials, it is preferable to use a dehydration condensation reaction of residual silanol groups contained in silica sol molecules. By promoting the reaction between the hydroxyl groups of the silanol group with the catalyst, it is possible to form a continuous film that cures the void structure in a short time. Examples of the catalyst include a photoactive catalyst and a thermally active catalyst. According to the photoactive catalyst, for example, the pulverized products can be chemically bonded (for example, crosslinked) without being heated. According to this, for example, since shrinkage due to heating hardly occurs, a higher porosity can be maintained. In addition to or instead of the catalyst, a substance that generates a catalyst (catalyst generator) may be used. For example, in addition to or instead of the photoactive catalyst, a substance that generates a catalyst by light (photocatalyst generator) may be used, or in addition to or instead of the thermally active catalyst A substance that generates water (thermal catalyst generator) may be used. The photocatalyst generator is not particularly limited, and examples thereof include a photobase generator (a substance that generates a basic catalyst by light irradiation), a photoacid generator (a substance that generates an acidic catalyst by light irradiation), and the like. A photobase generator is preferred. Examples of the photobase generator include 9-anthrylmethyl N, N-diethylcarbamate (trade name WPBG-018), (E) -1- [3- (2- Hydroxyphenyl) -2-propenoyl] piperidine ((E) -1- [3- (2-hydroxyphenyl) -2-propenoyl] piperidine, trade name WPBG-027), 1- (anthraquinone-2-yl) ethyl imidazolecarboxy Rate (1- (anthraquinon-2-yl) ethyl imidazolecarboxylate, trade name WPBG-140), 2-nitrophenylmethyl 4-methacryloyloxypiperidine-1-carboxylate (trade name WPBG-165), 1,2-diisopropyl- 3- [bis (dimethylamino) methylene] guanidinium 2- (3-benzoylphenyl) propionate (trade name WPBG-266), 1,2 -Dicyclohexyl-4,4,5,5-tetramethylbiguanidinium n-butyltriphenylborate (trade name WPBG-300), 2- (9-oxoxanthen-2-yl) propionic acid 1,5,7 -Triazabicyclo [4.4.0] dec-5-ene (manufactured by Tokyo Chemical Industry Co., Ltd.) and a compound containing 4-piperidinemethanol (trade name HDPD-PB100: manufactured by Heraeus). The trade names including “WPBG” are trade names of Wako Pure Chemical Industries, Ltd. Examples of the photoacid generator include aromatic sulfonium salts (trade name SP-170: ADEKA), triarylsulfonium salts (trade name CPI101A: San Apro), and aromatic iodonium salts (trade name Irgacure 250: Ciba Japan). Company). Further, the catalyst for chemically bonding the pulverized materials to each other is not limited to the photoactive catalyst and the photocatalyst generator, and may be a thermally active catalyst such as urea or a thermal catalyst generator. Examples of the catalyst for chemically bonding the pulverized materials include basic catalysts such as potassium hydroxide, sodium hydroxide and ammonium hydroxide, and acid catalysts such as hydrochloric acid, acetic acid and oxalic acid. Of these, base catalysts are preferred. The catalyst for chemically bonding the pulverized materials is used, for example, by adding to the sol particle liquid (for example, suspension) containing the pulverized material immediately before coating, or mixing the catalyst in a solvent. It can be used as a liquid. The mixed liquid may be, for example, a coating liquid that is directly added and dissolved in the sol particle liquid, a solution in which the catalyst is dissolved in a solvent, or a dispersion liquid in which the catalyst is dispersed in a solvent. The solvent is not particularly limited, and examples thereof include water, buffer solutions, and various organic solvents.

[Crosslinking aid]
In the silica porous particle sol solution of the present invention, when the silica porous particle is a pulverized product of a gel-like silicon compound obtained from a silicon compound containing at least a trifunctional or lower saturated bond functional group, It may contain a crosslinking aid for indirectly bonding. The cross-linking aid enters between the particles, and the particles and the cross-linking aid interact or bond with each other, so that it is possible to bond particles that are slightly apart from each other and efficiently increase the strength. It becomes possible. As the crosslinking aid, a polycrosslinked silane monomer is preferable. Specifically, the multi-crosslinked silane monomer has, for example, an alkoxysilyl group having 2 or more and 3 or less, the chain length between alkoxysilyl groups may be 1 to 10 carbon atoms, and an element other than carbon May also be included. Examples of the crosslinking aid include bis (trimethoxysilyl) ethane, bis (triethoxysilyl) ethane, bis (trimethoxysilyl) methane, bis (triethoxysilyl) methane, bis (triethoxysilyl) propane, bis (Trimethoxysilyl) propane, bis (triethoxysilyl) butane, bis (trimethoxysilyl) butane, bis (triethoxysilyl) pentane, bis (trimethoxysilyl) pentane, bis (triethoxysilyl) hexane, bis (tri Methoxysilyl) hexane, bis (trimethoxysilyl) -N-butyl-N-propyl-ethane-1,2-diamine, tris- (3-trimethoxysilylpropyl) isocyanurate, tris- (3-triethoxysilylpropyl) ) Isocyanurate and the like. The addition amount of the crosslinking aid is not particularly limited, and is, for example, 0.01 to 20% by weight, 0.05 to 15% by weight, or 0.1 to 10% by weight with respect to the solid content in the gel. .

  Although the manufacturing method of the silica porous particle sol liquid of this invention is demonstrated below, the following description can be used for the silica porous particle sol liquid of this invention. Further, in the present invention, when the dispersoid is other than the porous silica particles, the following explanation can be used unless there are special circumstances.

  In the method for producing a silica porous particle sol solution of the present invention, the mixing step is a step of mixing the silica porous particles and the dispersion medium as described above. Specifically, for example, at least 3 This is a step of mixing a pulverized product of a gel-like silicon compound obtained from a silicon compound containing a functionally saturated functional group and a dispersion medium. In this invention, when the said silica porous particle is the ground material of the said gel-like silicon compound, the said ground material can be obtained from the gel-like silicon compound grind | pulverized by the grinding | pulverization process mentioned later, for example. Moreover, the pulverized product of the gel-like silicon compound can be obtained, for example, from the gel-like silicon compound after the aging treatment in which the aging step described later is performed by a pulverizing step described later.

  In the production method of the present invention, the gelation step is a step of producing a gel-like silicon compound by gelling the silicon compound containing at least a trifunctional or lower saturated bond functional group in a solvent. The gelation step is, for example, a step of gelling the monomer silicon compound by a dehydration condensation reaction in the presence of a dehydration condensation catalyst, whereby a gel-like silicon compound is obtained. As described above, the gel-like silicon compound has a residual silanol group, and the residual silanol group is appropriately adjusted according to a chemical bond between pulverized products of the gel-like silicon compound described later. Is preferred. In addition, the said gelatinization process is not an essential process in the manufacturing method of this invention.

  In the gelation step, the silicon compound is not particularly limited as long as it is gelled by a dehydration condensation reaction. By the dehydration condensation, for example, the silicon compounds are bonded. The bond between the silicon compounds is, for example, a hydrogen bond or an intermolecular force bond.

  Examples of the silicon compound include a silicon compound represented by the following formula (1). Since the silicon compound of the formula (1) has a hydroxyl group, the silicon compound of the formula (1) can be hydrogen bonded or intermolecularly bonded through, for example, each hydroxyl group.

In the formula (1), for example, X is 2, 3 or 4, and R ¹ is a linear or branched alkyl group. The number of carbon atoms of R ¹ is, for example, 1-6, 1-4, 1-2. Examples of the linear alkyl group include a methyl group, an ethyl group, a propyl group, a butyl group, a pentyl group, and a hexyl group. Examples of the branched alkyl group include an isopropyl group and an isobutyl group. X is, for example, 3 or 4.

Specific examples of the silicon compound represented by the formula (1) include a compound represented by the following formula (1 ′) in which X is 3. In the following formula (1 ′), R ¹ is the same as in the above formula (1), and is, for example, a methyl group. When R ¹ is a methyl group, the silicon compound is tris (hydroxy) methylsilane. When X is 3, the silicon compound is, for example, a trifunctional silane having three functional groups.

  Further, specific examples of the silicon compound represented by the formula (1) include a compound in which X is 4. In this case, the silicon compound is, for example, a tetrafunctional silane having four functional groups.

  The silicon compound may be, for example, a precursor that forms the silicon compound of the formula (1) by hydrolysis. The precursor is not particularly limited as long as it can generate the silicon compound by hydrolysis, and specific examples thereof include a compound represented by the formula (2).

  When the silicon compound is a precursor represented by the formula (2), the production method of the present invention may include, for example, a step of hydrolyzing the precursor prior to the gelation step.

  The hydrolysis method is not particularly limited, and can be performed, for example, by a chemical reaction in the presence of a catalyst. Examples of the catalyst include acids such as oxalic acid and acetic acid. The hydrolysis reaction can be performed, for example, by slowly dropping an aqueous solution of oxalic acid into the dimethyl sulfoxide solution of the silicon compound precursor in a room temperature environment and then stirring the mixture for about 30 minutes. When hydrolyzing the silicon compound precursor, for example, by completely hydrolyzing the alkoxy group of the silicon compound precursor, further heating and immobilization after gelation / aging / void structure formation, It can be expressed efficiently.

  In the present invention, examples of the silicon compound include a hydrolyzate of trimethoxy (methyl) silane.

  The silicon compound of the monomer is not particularly limited, and can be appropriately selected according to the use of the porous silicone body to be produced, for example. In the production of the silicone porous body, for example, when importance is attached to low refractive index, the silicon compound is preferably the trifunctional silane from the viewpoint of excellent low refractive index, and also has strength (for example, scratch resistance). When importance is attached to the above, the tetrafunctional silane is preferred from the viewpoint of excellent scratch resistance. Moreover, the said silicon compound used as the raw material of the said gel-like silicon compound may use only 1 type, for example, and may use 2 or more types together. As a specific example, the silicon compound may include, for example, only the trifunctional silane, may include only the tetrafunctional silane, may include both the trifunctional silane and the tetrafunctional silane, Furthermore, other silicon compounds may be included. When two or more types of silicon compounds are used as the silicon compound, the ratio is not particularly limited and can be set as appropriate.

  The gelation of the silicon compound can be performed, for example, by a dehydration condensation reaction between the silicon compounds. The dehydration condensation reaction is preferably performed, for example, in the presence of a catalyst. Examples of the catalyst include acid catalysts such as hydrochloric acid, oxalic acid, and sulfuric acid, and ammonia, potassium hydroxide, sodium hydroxide, ammonium hydroxide, and the like. And a dehydration condensation catalyst such as a base catalyst. The dehydration condensation catalyst may be an acid catalyst or a base catalyst, but a base catalyst is preferred. In the dehydration condensation reaction, the amount of the catalyst added to the silicon compound is not particularly limited, and the catalyst is, for example, 0.1 to 10 mol, 0.05 to 7 mol, relative to 1 mol of the silicon compound. 0.1 to 5 mol.

  The gelation of the silicon compound is preferably performed in a solvent, for example. For example, one type of solvent may be used, or two or more types may be used in combination. Hereinafter, the solvent used for the gelation is also referred to as “gelling solvent”. As will be described later, when the gelled silicon compound is subjected to a grinding treatment after the gelling solvent is replaced with a grinding solvent, a solvent different from the grinding solvent is used as the gelling solvent. Specifically, for example, dimethyl sulfoxide (DMSO), N-methylpyrrolidone (NMP), N, N-dimethylacetamide (DMAc), dimethylformamide (DMF), γ-butyllactone (GBL), acetonitrile (MeCN), ethylene glycol ethyl ether (EGEE), or the like may be used. On the other hand, when the gelling solvent is used as the grinding solvent without replacing the gelling solvent with the grinding solvent, the same gelling solvent as the grinding solvent can be used.

  The gelation conditions are not particularly limited. The process temperature with respect to the said solvent containing the said silicon compound is 20-30 degreeC, 22-28 degreeC, 24-26 degreeC, for example, and processing time is 1-60 minutes, 5-40 minutes, 10-30, for example. Minutes. When performing the said dehydration condensation reaction, the process conditions in particular are not restrict | limited, These illustrations can be used. By performing the gelation, for example, a siloxane bond grows, primary particles of the silicon compound are formed, and further the reaction proceeds, whereby the primary particles are linked in a bead shape to form a three-dimensional gel. Generated.

  The gel form of the gel silicon compound obtained in the gelation step is not particularly limited. “Gel” generally refers to a solidified state in which a solute has a structure in which it loses independent motility due to interaction and aggregates. In addition, among gels, generally, a wet gel includes a dispersion medium and a solute has a uniform structure in the dispersion medium. A xerogel is a network structure in which the solvent is removed and the solute has voids. The one that takes In the present invention, for example, wet gel is preferably used as the gel silicon compound. The remaining silanol group of the gel-like silicon compound is not particularly limited, and for example, the ranges described later can be exemplified similarly.

  For example, the gelled silicon compound obtained by the gelation may be subjected to the pulverization step as it is, but may be subjected to an aging treatment in the aging step before the pulverization step. In the aging step, the gel silicon compound is aged in a solvent. In the aging step, the conditions for the aging treatment are not particularly limited. For example, the gel-like silicon compound may be incubated in a solvent at a predetermined temperature. According to the aging treatment, for example, the gel-like silicon compound having a three-dimensional structure obtained by gelation can further grow the primary particles, thereby increasing the size of the particles themselves. It is. As a result, the contact state of the neck portion where the particles are in contact can be increased from point contact to surface contact, for example. The gel silicon compound subjected to the aging treatment as described above, for example, increases the strength of the gel itself, and as a result, can further improve the strength of the three-dimensional basic structure of the pulverized product after pulverization. . Thereby, when a coating film is formed using the silica porous particle sol solution of the present invention, for example, even in the drying step after coating, the pore size of the void structure in which the three-dimensional basic structure is deposited is Further, it is possible to suppress shrinkage due to volatilization of the solvent in the coating film generated in the drying step.

  In the aging step, the gel silicon compound is incubated in the solvent at a temperature of 30 ° C. or higher, 35 ° C. or higher, 40 ° C. or higher (aging temperature). For example, the upper limit of the aging temperature is 80 ° C. or lower, 75 ° C. or lower, and 70 ° C. or lower. The range of the said processing temperature is 30-80 degreeC, 35-75 degreeC, 40-70 degreeC, for example. The predetermined time for performing the aging step is not particularly limited, and the lower limit thereof is, for example, 5 hours or more, 10 hours or more, 15 hours or more, and the upper limit thereof is, for example, 50 hours or less, 40 hours or less, 30 The range is, for example, 5 to 50 hours, 10 to 40 hours, and 15 to 30 hours. The optimum conditions for aging can be set, for example, as described above, such that the gel-like silicon compound can increase the size of the primary particles and increase the contact area of the neck portion. preferable. In the aging step, the temperature of the aging treatment preferably takes into account, for example, the boiling point of the solvent used. In the aging treatment, for example, if the aging temperature is too high, the solvent is excessively volatilized, and there is a possibility that problems such as closing of the pores of the three-dimensional void structure occur due to the concentration of the coating solution. is there. On the other hand, in the aging treatment, for example, if the aging temperature is too low, the effect due to the aging is not sufficiently obtained, temperature variation with time of the mass production process increases, and a product with poor quality may be produced. There is.

  In the aging treatment, for example, the same solvent as in the gelation step can be used, and specifically, the reaction product after the gel treatment (that is, the solvent containing the gel silicon compound) is applied as it is. Is preferred. The number of moles of residual silanol groups contained in the gelled silicon compound that has been subjected to aging treatment after gelation is, for example, the number of moles of alkoxy groups in the raw material used for gelation (for example, the silicon compound or its precursor). Is the ratio of residual silanol groups when the value is 100, the lower limit is, for example, 50% or more, 40% or more, 30% or more, and the upper limit is, for example, 1% or less, 3% or less, 5% The range is, for example, 1 to 50%, 3 to 40%, and 5 to 30%. For the purpose of increasing the hardness of the gel silicon compound, for example, the lower the number of moles of residual silanol groups, the better. If the number of residual silanol groups is too high, for example, in the formation of the silicone porous body, there is a possibility that the void structure cannot be retained before the precursor of the silicone porous body is crosslinked. On the other hand, if the number of moles of residual silanol groups is too low, for example, in the bonding step, the precursor of the silicone porous body cannot be crosslinked, and sufficient film strength may not be imparted. The above is an example of residual silanol groups. For example, when the silicon compound modified with various reactive functional groups is used as the raw material of the gel silicon compound, However, the same phenomenon can be applied.

  In the present invention, the pulverizing step is a step of pulverizing the gel silica compound in a solvent as described above. The pulverization may be performed, for example, on the gel silicon compound after the gelation step, or may be performed on the gel silicon compound after aging that has been subjected to the aging treatment.

  In the pulverization, for example, the gel-like silicon compound in the gelation solvent may be pulverized as it is, or after the gelation solvent is replaced with another solvent, the other solvent is used. You may grind | pulverize with respect to the gelatinous silicon compound in it. Further, when the aging step is performed on the gelled silicon compound, for example, the catalyst and the solvent used in the gelation step remain after the aging step, and further gelation occurs over time. If it affects the pot life of the resulting silica porous particle sol solution, or if the drying efficiency when drying the coating film formed using the silica porous particle sol solution is reduced, substitute with another solvent. It is preferable to do. Hereinafter, the other solvent is also referred to as a “grinding solvent”.

  For the pulverization, for example, the same solvent as in the gelation step and the aging step may be used, or a solvent different from that in the gelation step and the aging step may be used. In the former case, for example, the aging step and the pulverization treatment can be performed as they are on the reaction product after the gelation step (for example, the gelation solvent containing the gel silicon compound). In the latter case, after the gelling step, the reaction product after the gelation step (for example, the gelation solvent containing the gelled silicon compound) is subjected to the aging step as it is, and then the gelation solvent is added. After substituting with the solvent, the gelled silicon compound in the other solvent may be pulverized.

  The grinding solvent is not particularly limited, and for example, the organic solvent having a boiling point of 70 ° C. or higher and lower than 180 ° C. and a saturated vapor pressure at 20 ° C. of 15 kPa or lower can be used.

  By replacing the gelling solvent with the grinding solvent, for example, a more uniform coating film can be formed in the coating film formation described below.

  The method for pulverizing the gel-like silicon compound is not particularly limited, and is performed by, for example, an ultrasonic homogenizer, a high-speed rotation homogenizer, a pulverizer using other cavitation phenomenon, or a wet atomizer that obliquely collides liquids at high pressure. be able to. A device for performing media grinding such as a ball mill physically destroys the void structure of the gel at the time of grinding, whereas a cavitation type grinding device preferable for the present invention such as a homogenizer is, for example, a gel-less system. The relatively weakly bonded silica particle bonding surface already contained in the three-dimensional structure is peeled off with a high shear force. Thus, by pulverizing the gel-like silicon compound, a new sol three-dimensional structure is obtained, and the three-dimensional structure has, for example, a void structure having a certain range of particle size distribution in the formation of a coating film. It can be retained, and the void structure can be re-formed by deposition during coating and drying. The conditions for the pulverization are not particularly limited. For example, it is preferable that the gel can be pulverized without volatilizing the solvent by instantaneously applying a high-speed flow. For example, it is preferable to grind so as to obtain a pulverized product having a particle size variation as described above (for example, a volume average particle size or a particle size distribution). If the amount of work such as pulverization time and strength is insufficient, for example, coarse particles remain, and fine pores cannot be formed, appearance defects increase, and high quality may not be obtained. is there. On the other hand, when the work amount is excessive, for example, the sol particles are finer than the desired particle size distribution, and the void size deposited after coating / drying may become fine and may not satisfy the desired porosity. .

  The ratio of residual silanol groups contained in the pulverized product after the pulverization step is not particularly limited, and is, for example, the same as the range exemplified for the gel silicon compound after the aging treatment.

  After the pulverization step, the ratio of the pulverized product in the solvent containing the pulverized product is not particularly limited, and examples thereof include the conditions in the silica porous particle sol solution of the present invention described above. The ratio may be, for example, the condition of the solvent itself containing the pulverized product after the pulverization step, or after the pulverization step and before the use as the silica porous particle sol solution. There may be.

  As described above, the silica porous particle sol solution of the present invention containing the silica porous particles and the dispersion medium can be produced. In the present invention, for example, when a pulverized product of a gel-like silicon compound is used as the silica porous particle, a catalyst that chemically bonds the pulverized product may be added during or after each step. . With this catalyst, for example, the pulverized products can be chemically bonded in a bonding step described later. The catalyst may be, for example, a catalyst that promotes cross-linking between the pulverized products. As a chemical reaction for chemically bonding the pulverized materials, it is preferable to use a dehydration condensation reaction of residual silanol groups contained in silica sol molecules. By promoting the reaction between the hydroxyl groups of the silanol group with the catalyst, it is possible to form a continuous film that cures the void structure in a short time. Examples of the catalyst include a photoactive catalyst and a thermally active catalyst. According to the photoactive catalyst, for example, the pulverized products can be chemically bonded (for example, crosslinked) without being heated. According to this, for example, since shrinkage due to heating hardly occurs, a higher porosity can be maintained. In addition to or instead of the catalyst, a substance that generates a catalyst (catalyst generator) may be used. For example, in addition to or instead of the photoactive catalyst, a substance that generates a catalyst by light (photocatalyst generator) may be used, or in addition to or instead of the thermally active catalyst A substance that generates water (thermal catalyst generator) may be used. The photocatalyst generator is not particularly limited, and examples thereof include a photobase generator (a substance that generates a basic catalyst by light irradiation), a photoacid generator (a substance that generates an acidic catalyst by light irradiation), and the like. A photobase generator is preferred. Examples of the photobase generator include 9-anthrylmethyl N, N-diethylcarbamate (trade name WPBG-018), (E) -1- [3- (2- Hydroxyphenyl) -2-propenoyl] piperidine ((E) -1- [3- (2-hydroxyphenyl) -2-propenoyl] piperidine, trade name WPBG-027), 1- (anthraquinone-2-yl) ethyl imidazolecarboxy Rate (1- (anthraquinon-2-yl) ethyl imidazolecarboxylate, trade name WPBG-140), 2-nitrophenylmethyl 4-methacryloyloxypiperidine-1-carboxylate (trade name WPBG-165), 1,2-diisopropyl- 3- [bis (dimethylamino) methylene] guanidinium 2- (3-benzoylphenyl) propionate (trade name WPBG-266), 1,2 -Dicyclohexyl-4,4,5,5-tetramethylbiguanidinium n-butyltriphenylborate (trade name WPBG-300), 2- (9-oxoxanthen-2-yl) propionic acid 1,5,7 -Triazabicyclo [4.4.0] dec-5-ene (manufactured by Tokyo Chemical Industry Co., Ltd.) and a compound containing 4-piperidinemethanol (trade name HDPD-PB100: manufactured by Heraeus). As described above, the trade names including the “WPBG” are trade names of Wako Pure Chemical Industries, Ltd. Examples of the photoacid generator include aromatic sulfonium salts (trade name SP-170: ADEKA), triarylsulfonium salts (trade name CPI101A: San Apro), and aromatic iodonium salts (trade name Irgacure 250: Ciba Japan). Company). Further, the catalyst for chemically bonding the pulverized materials to each other is not limited to the photoactive catalyst and the photocatalyst generator, and may be a thermally active catalyst such as urea or a thermal catalyst generator. Examples of the catalyst for chemically bonding the pulverized materials include basic catalysts such as potassium hydroxide, sodium hydroxide and ammonium hydroxide, and acid catalysts such as hydrochloric acid, acetic acid and oxalic acid. Of these, base catalysts are preferred. The catalyst for chemically bonding the pulverized materials is used, for example, by adding to the sol particle liquid (for example, suspension) containing the pulverized material immediately before coating, or mixing the catalyst in a solvent. It can be used as a liquid. The mixed liquid may be, for example, a coating liquid that is directly added and dissolved in the sol particle liquid, a solution in which the catalyst is dissolved in a solvent, or a dispersion liquid in which the catalyst is dispersed in a solvent. The solvent is not particularly limited, and examples thereof include water, buffer solutions, and various organic solvents.

[2. Laminated film]
As described above, the laminated film of the present invention includes a void layer having a high porosity (porosity), an improved production efficiency, and an excellent appearance. In addition, in the following, the laminated film roll of the present invention (the laminated film of the present invention that is in the form of a roll) and the laminated film of the present invention that is not in the form of a roll may be collectively referred to simply as “the laminated film of the present invention”. . That is, hereinafter, the “laminated film of the present invention” includes the laminated film roll of the present invention unless otherwise specified. In addition, the laminated | multilayer film of this invention which is not roll shape can cut out and obtain a part of laminated film roll of this invention, for example.

  The laminated film of the present invention can be made into, for example, a roll-shaped laminated film (laminated film roll of the present invention), and has advantages such as good production efficiency and easy handling. Moreover, the laminated film of the present invention can be continuously produced as a roll-shaped product, for example, by forming on a soft resin film, and is easy to handle as a roll. In addition, although the manufacturing method of the laminated | multilayer film of this invention is not specifically limited, For example, it can manufacture with the manufacturing method of the said laminated | multilayer film of this invention.

  The laminated film of the present invention is, for example, a laminated film including the void layer and the resin film, and the void layer is laminated on the resin film. It can be said that the laminated film is a low refractive material having the above-mentioned characteristics. The laminated film of the present invention may further include an intermediate layer and an adhesive layer described later.

  In the laminated film of the present invention, the resin film is not particularly limited, and types of the resin include, for example, polyethylene terephthalate (PET), acrylic, cellulose acetate propionate (CAP), cycloolefin polymer (COP), and triacetate. Examples thereof include thermoplastic resins having excellent transparency such as (TAC), polyethylene naphthalate (PEN), polyethylene (PE), and polypropylene (PP).

  For example, the void layer (the void layer of the present invention) in the laminated film roll or laminated film of the present invention may be laminated directly on the resin film or may be laminated via another layer.

  The void layer of the present invention has, for example, a scratch resistance of 60 to 100% due to Bencot (registered trademark) indicating film strength. With such film strength, for example, it is resistant to physical impact during winding and use during manufacture. The lower limit of the scratch resistance is, for example, 60% or more, 80% or more, 90% or more, and the upper limit thereof is, for example, 100% or less, 99% or less, 98% or less, and the range is For example, they are 60 to 100%, 80 to 99%, and 90 to 98%.

  The scratch resistance can be measured, for example, by the following method.

(Evaluation of scratch resistance)
(1) Sampling a void layer (a void layer of the present invention) applied and formed on an acrylic film in a circular shape having a diameter of about 15 mm. When other layers (for example, an intermediate layer and an adhesive layer) are present on the void layer, sampling is performed after the other layers are removed.
(2) Next, with respect to the sample, silicon is identified with fluorescent X-rays (manufactured by Shimadzu Corporation: ZSX Primus II), and the Si coating amount (Si ₀ ) is measured. Next, with respect to the gap layer on the acrylic film, the gap layer is cut to 50 mm × 100 mm from the vicinity sampled, and fixed to a glass plate (thickness 3 mm), and then according to Bencott (registered trademark). Perform a sliding test. The sliding condition is a weight of 100 g and 10 reciprocations.
(3) The residual amount of Si (Si ₁ ) after the scratch test is measured by sampling and fluorescent X measurement in the same manner as in (1) above from the gap layer after sliding. The scratch resistance is defined by the Si residual ratio (%) before and after the sliding test by Bencott (registered trademark), and is represented by the following formula.
Scratch resistance (%) = [remaining Si amount (Si ₁ ) / Si coating amount (Si ₀ )] × 100 (%)

  Moreover, the laminated film roll or laminated film of the present invention has, for example, a folding resistance of 100 times or more according to the MIT test showing flexibility. By having such flexibility, it is excellent in handleability at the time of winding or use during continuous production.

  The lower limit of the folding endurance number is, for example, 100 times or more, 500 times or more, 1000 times or more, and the upper limit is not particularly limited, for example, 10,000 times or less, and the range is, for example, 100 -10000 times, 500-10000 times, 1000-10000 times.

  The flexibility means, for example, ease of deformation of a substance. The folding endurance by the MIT test can be measured by the following method, for example.

(Evaluation of folding test)
The void layer (the void layer of the present invention) is cut into a 20 mm × 80 mm strip, and then attached to an MIT folding tester (manufactured by Tester Sangyo Co., Ltd .: BE-202), and a load of 1.0 N is applied. The chuck part that embeds the gap layer uses R 2.0 mm, performs the folding endurance up to 10,000 times, and sets the number of times when the gap layer is broken as the number of folding endurances.

In the void layer of the present invention, the film density is not particularly limited, and the lower limit thereof is, for example, 1 g / cm ³ or more, 10 g / cm ³ or more, 15 g / cm ³ or more, and the upper limit thereof is, for example, 50 g / cm ^3. cm ³ or less, 40 g / cm ³ or less, 30 g / cm ³ or less, and a 2.1 g / cm ³ or less, that range, for ^example, 5 to 50 g / cm ^3, 10 to 40 g / cm 3, 15 to 30 g / cm ³ , 1 to 2.1 g / cm ³ . In the void layer of the present invention, the lower limit of the porosity (porosity) based on the film density is, for example, 50% or more, 70% or more, 85% or more, and the upper limit thereof is, for example, 98. % Or less and 95% or less, and the range is, for example, 50 to 98%, 70 to 95%, 85 to 95%.

  The film density can be measured, for example, by the following method, and the porosity (porosity) can be calculated, for example, as follows based on the film density.

(Evaluation of membrane density and porosity (porosity))
After forming a void layer (a void layer of the present invention) on a base material (acrylic film), the total void region of the laminate was measured using an X-ray diffractometer (RINTKU 2000: RINT-2000). The X-ray reflectivity of is measured. After performing Intensity and 2θ fitting, the film density (g / cm ³ ) is calculated from the total reflection critical angle of the laminate (void layer / base material), and the porosity (porosity) ( P%) is calculated from the following equation.
Porosity (porosity) (P%) = 45.48 × membrane density (g / cm ³ ) +100 (%)

  The void layer of the present invention has, for example, a pore structure. The pore size of the hole refers to the diameter of the major axis among the major axis diameter and minor axis diameter of the void (hole). The pore size is, for example, 2 nm to 500 nm. The lower limit of the void size is, for example, 2 nm or more, 5 nm or more, 10 nm or more, 20 nm or more, and the upper limit thereof is, for example, 500 nm or less, 200 nm or less, 100 nm or less, and the range thereof is, for example, 2 nm to 500 nm, 5 nm to 500 nm, 10 nm to 200 nm, 20 nm to 100 nm. Since a preferable void size is determined depending on the use of the void structure, for example, it is necessary to adjust the void size to a desired void size according to the purpose. The void size can be evaluated by the following method, for example.

(Evaluation of gap size)
In the present invention, the void size can be quantified by a BET test method. Specifically, 0.1 g of the sample (the void layer of the present invention) was introduced into the capillary of a specific surface area measuring device (manufactured by Micromeritic: ASAP2020), and then dried under reduced pressure at room temperature for 24 hours. Degas the gas in the structure. The adsorption isotherm is drawn by adsorbing nitrogen gas to the sample, and the pore distribution is obtained. Thereby, the gap size can be evaluated.

  The void layer of the present invention may have, for example, a pore structure (porous structure) as described above, and may be, for example, an open cell structure in which the pore structure is continuous. The open cell structure means, for example, that the porous structure of the silicone is three-dimensionally connected with the pore structure, and the internal voids of the pore structure can be said to be continuous. When the porous body has an open cell structure, it is possible to increase the porosity (porosity) in the bulk material. However, when using closed cell particles such as hollow silica, A foam structure cannot be formed. On the other hand, the void layer of the present invention is applied, for example, when silica sol particles (a crushed product of a gel-like silicon compound that forms a sol) are used, because the particles have a three-dimensional dendritic structure. In the film (sol coating film containing a pulverized product of the gel-like silicon compound), the dendritic particles settle and deposit, so that an open cell structure can be easily formed. The void layer of the present invention more preferably forms a monolith structure in which the open cell structure has a plurality of pore distributions. The monolith structure refers to, for example, a structure in which nano-sized fine voids exist and a hierarchical structure that exists as an open cell structure in which the nano voids are aggregated. When the monolith structure is formed, for example, while providing film strength with fine voids, high void ratio (porosity) is provided with coarse open-cell voids, and film strength and high porosity (porosity) are provided. And both. In order to form these monolithic structures, for example, it is preferable to first control the pore distribution of the generated void structure in the gel (gel-like silicon compound) before pulverization into the silica sol particles. For example, when the gel-like silicon compound is pulverized, the monolith structure can be formed by controlling the particle size distribution of the pulverized silica sol particles to a desired size.

  In the void layer of the present invention, the haze indicating transparency is not particularly limited, and the upper limit is, for example, less than 5% and less than 3%. The lower limit is, for example, 0.1% or more and 0.2% or more, and the range is, for example, 0.1% or more and less than 5%, or 0.2% or more and less than 3%.

  The haze can be measured, for example, by the following method.

(Evaluation of haze)
The void layer (the void layer of the present invention) is cut into a size of 50 mm × 50 mm, and set in a haze meter (manufactured by Murakami Color Research Laboratory Co., Ltd .: HM-150) to measure haze. The haze value is calculated from the following formula.
Haze (%) = [diffuse transmittance (%) / total light transmittance (%)] × 100 (%)

  The refractive index is generally the ratio of the transmission speed of the wavefront of light in vacuum to the propagation speed in the medium, which is called the refractive index of the medium. The upper limit of the refractive index of the void layer of the present invention is, for example, 1.25 or less, 1.20 or less, or 1.15 or less, and the lower limit thereof is, for example, 1.05 or more, 1.06 or more, 1 The range is, for example, 1.05 or more and 1.25 or less, 1.06 or more and 1.20 or less, and 1.07 or more and 1.15 or less.

  In the present invention, the refractive index means a refractive index measured at a wavelength of 550 nm unless otherwise specified. Moreover, the measuring method of a refractive index is not specifically limited, For example, it can measure with the following method.

(Evaluation of refractive index)
After forming a void layer (the void layer of the present invention) on the acrylic film, it is cut into a size of 50 mm x 50 mm, and this is bonded to the surface of a glass plate (thickness: 3 mm) with an adhesive layer. The back surface central part (diameter of about 20 mm) of the glass plate is painted with black magic to prepare a sample that does not reflect on the back surface of the glass plate. The sample is set in an ellipsometer (manufactured by JA Woollam Japan: VASE), the refractive index is measured under the conditions of a wavelength of 500 nm and an incident angle of 50 to 80 degrees, and the average value is taken as the refractive index.

  The adhesive peel strength showing the adhesion between the void layer of the present invention and the adhesive layer laminated thereon is not particularly limited, and the lower limit thereof is, for example, 1 N / 25 mm or more, 1.3 N / 25 mm. Above, 1.5N / 25mm or more, 2N / 25mm or more, 3N / 25mm or more, the upper limit is, for example, 30N / 25mm or less, 20N / 25mm or less, 10N / 25mm or less, and the range is, for example, 1 to 30 N / 25 mm, 2 to 20 N / 25 mm, and 3 to 10 N / 25 mm.

  The measuring method of the said adhesive peel strength is not specifically limited, For example, it can measure with the following method.

(Evaluation of adhesive peel strength)
The laminated film of the present invention is sampled into a 50 mm × 140 mm strip, and the sample is fixed to a stainless steel plate with a double-sided tape. An acrylic adhesive layer (thickness 20 μm) is bonded to a PET film (T100: manufactured by Mitsubishi Plastics Film Co., Ltd.), and the adhesive tape piece cut to 25 mm × 100 mm is bonded to the gap layer, and the PET film Laminate. Next, the sample is chucked on an autograph tensile tester (manufactured by Shimadzu Corporation: AG-Xplus) so that the distance between chucks becomes 100 mm, and then a tensile test is performed at a tensile speed of 0.3 m / min. . Let the average test force which performed the 50 mm peel test be adhesive peel strength.

  The thickness of the void layer of the present invention is not particularly limited, and the lower limit thereof is, for example, 0.01 μm or more, 0.05 μm or more, 0.1 μm or more, 0.3 μm or more, and the upper limit thereof is, for example, 1000 μm or less. 100 μm or less, 80 μm or less, 50 μm or less, 10 μm or less, and the range thereof is, for example, 0.01 to 100 μm.

  The void layer of the present invention includes, for example, porous silica particles, and specifically includes, for example, a pulverized product of a gel compound, and the pulverized product is chemically bonded to each other. In the void layer of the present invention, the form of chemical bonding (chemical bonding) between the pulverized products is not particularly limited, and specific examples of the chemical bonding include, for example, cross-linking. The method of chemically bonding the pulverized products will be described in detail in the production method of the present invention.

  The gel form of the gel compound is not particularly limited. “Gel” generally refers to a solidified state in which a solute has a structure in which it loses independent motility due to interaction and aggregates. In addition, among gels, generally, a wet gel includes a dispersion medium and a solute has a uniform structure in the dispersion medium. A xerogel is a network structure in which the solvent is removed and the solute has voids. The one that takes In the present invention, the gel compound may be, for example, a wet gel or a xerogel.

  Examples of the gel compound include gelled products obtained by gelling monomer compounds. Specifically, examples of the gel silicon compound include gelled products in which the monomer silicon compounds are bonded to each other, and specific examples include gelled products in which the monomer silicon compounds are bonded to each other through hydrogen bonding or intermolecular force bonding. Examples of the bond include a bond by dehydration condensation. The gelation method will be described later in the production method of the present invention.

  In the void layer of the present invention, the volume average particle diameter showing the particle size variation of the silica porous particles is not particularly limited, and the lower limit thereof is, for example, 0.10 μm or more, 0.20 μm or more, 0.40 μm or more. The upper limit is, for example, 2.00 μm or less, 1.50 μm or less, 1.00 μm or less, and the ranges thereof are, for example, 0.10 μm to 2.00 μm, 0.20 μm to 1.50 μm, 0.40 μm to 1.00 μm. The volume average particle diameter is measured by, for example, a particle size distribution evaluation apparatus such as a dynamic light scattering method and a laser diffraction method, and an electron microscope such as a scanning electron microscope (SEM) and a transmission electron microscope (TEM). Can do.

  The particle size distribution showing the particle size variation of the silica porous particles is not particularly limited. For example, particles having a particle size of 0.4 μm to 1 μm are 50 to 99.9 wt%, 80 to 99.8 wt%, It is 90 to 99.7% by weight, or particles having a particle diameter of 1 μm to 2 μm are 0.1 to 50% by weight, 0.2 to 20% by weight, and 0.3 to 10% by weight. The particle size distribution can be measured by, for example, a particle size distribution evaluation apparatus or an electron microscope.

  In the void layer of the present invention, the type of the porous silica particles is not particularly limited. Examples of the silica porous particles include gel silicon compounds. Although the case where the said silica porous particle is a gel-like compound is demonstrated as an example below, this invention is not restrict | limited to this.

  The crosslinking bond is, for example, a siloxane bond. Examples of the siloxane bond include T2 bond, T3 bond, and T4 bond shown below. When the void layer of the present invention has a siloxane bond, for example, it may have any one kind of bond, may have any two kinds of bonds, or may have all three kinds of bonds. Good. Among the siloxane bonds, the greater the ratio of T2 and T3, the more flexible and the expected properties of the gel can be expected, but the film strength becomes weaker. On the other hand, if the T4 ratio in the siloxane bond is large, the film strength is easily expressed, but the void size becomes small and the flexibility becomes brittle. For this reason, for example, it is preferable to change the ratio of T2, T3, and T4 according to the application.

  When the void layer of the present invention has the siloxane bond, the ratio of T2, T3, and T4 is, for example, when T2 is expressed as “1”, and T2: T3: T4 = 1: [1 to 100]. : [0-50], 1: [1-80]: [1-40], 1: [5-60]: [1-30].

  In the void layer of the present invention, for example, the silicon atoms contained are preferably siloxane bonded. As a specific example, the ratio of unbonded silicon atoms (that is, residual silanol) in the total silicon atoms contained in the void layer is, for example, less than 50%, 30% or less, or 15% or less.

  When the silica porous particles are the gel silicon compound, the silicon compound of the monomer is not particularly limited. Examples of the silicon compound of the monomer include a compound represented by the following formula (1). In the case where the gelled silicon compound is a gelled product in which monomeric silicon compounds are bonded to each other by hydrogen bonding or intermolecular force bonding as described above, the monomers of formula (1) are bonded to each other through, for example, each hydroxyl group. it can.

In the formula (1), for example, X is 2, 3 or 4, and R ¹ is a linear or branched alkyl group. The number of carbon atoms of R ¹ is, for example, 1-6, 1-4, 1-2. Examples of the linear alkyl group include a methyl group, an ethyl group, a propyl group, a butyl group, a pentyl group, and a hexyl group. Examples of the branched alkyl group include an isopropyl group and an isobutyl group. X is, for example, 3 or 4.

Specific examples of the silicon compound represented by the formula (1) include a compound represented by the following formula (1 ′) in which X is 3. In the following formula (1 ′), R ¹ is the same as in the above formula (1), and is, for example, a methyl group. When R ¹ is a methyl group, the silicon compound is tris (hydroxy) methylsilane. When X is 3, the silicon compound is, for example, a trifunctional silane having three functional groups.

  Further, specific examples of the silicon compound represented by the formula (1) include a compound in which X is 4. In this case, the silicon compound is, for example, a tetrafunctional silane having four functional groups.

  The monomeric silicon compound may be, for example, a hydrolyzate of a silicon compound precursor. The silicon compound precursor is not particularly limited as long as it can generate the silicon compound by hydrolysis, and specific examples thereof include a compound represented by the following formula (2).

In the formula (2), for example, X is 2, 3 or 4,
R ¹ and R ² are each a linear or branched alkyl group,
R ¹ and R ² may be the same or different,
R ^{1 s} may be the same as or different from each other when X is 2.
R ² may be the same as or different from each other.

Wherein X and ^{R 1} are, for example, the same as X and ^{R 1} in the formula (1). In addition, the ^{R 2} is, for example, can be exemplified for ^{R 1} is incorporated in the formula (1).

Specific examples of the silicon compound precursor represented by the formula (2) include compounds represented by the following formula (2 ′) in which X is 3. In the following formula (2 ′), R ¹ and R ² are the same as those in the formula (2), respectively. When R ¹ and R ² are methyl groups, the silicon compound precursor is trimethoxy (methyl) silane (hereinafter also referred to as “MTMS”).

  The monomeric silicon compound is preferably the trifunctional silane from the viewpoint of excellent low refractive index, for example. The silicon compound as the monomer is preferably the tetrafunctional silane from the viewpoint of excellent strength (for example, scratch resistance). Moreover, as for the silicon compound of the said monomer used as the raw material of the said gel-like silicon compound, only 1 type may be used and 2 or more types may be used together, for example. As a specific example, as the silicon compound of the monomer, for example, only the trifunctional silane may be included, only the tetrafunctional silane may be included, or both the trifunctional silane and the tetrafunctional silane may be included. In addition, other silicon compounds may be included. When two or more types of silicon compounds are used as the silicon compound of the monomer, the ratio is not particularly limited and can be set as appropriate.

  In the present invention, the adhesive layer is not particularly limited. In the present invention, the “adhesive layer” is, for example, a layer containing at least one of a pressure-sensitive adhesive and an adhesive, and may be, for example, a pressure-sensitive adhesive layer or an adhesive layer. In the present invention, “adhesive” and “adhesive layer” refer to, for example, an agent or layer premised on re-peeling of the adherend. In the present invention, “adhesive” and “adhesive layer” refer to, for example, an agent or a layer that does not assume re-peeling of the adherend. However, in the present invention, “pressure-sensitive adhesive” and “adhesive” are not necessarily clearly distinguished, and “pressure-sensitive adhesive layer” and “adhesive layer” are not necessarily clearly distinguished. In this invention, the adhesive or adhesive which forms the said adhesive layer is not specifically limited, For example, a general adhesive or adhesive etc. can be used. Examples of the pressure-sensitive adhesive or adhesive include acrylic, vinyl alcohol, silicone, polyester, polyurethane, and polyether polymer adhesives, rubber adhesives, and the like. Moreover, the adhesive agent comprised from the water-soluble crosslinking agent of vinyl alcohol polymers, such as glutaraldehyde, melamine, and oxalic acid, etc. are mentioned. These pressure-sensitive adhesives and adhesives may be used alone or in combination (for example, mixing, lamination, etc.). Although the thickness of the said adhesive layer is not restrict | limited in particular, For example, it is 0.1-100 micrometers, 5-50 micrometers, 10-30 micrometers, or 12-25 micrometers.

  In the present invention, the intermediate layer is not particularly limited. For example, as described later, the intermediate layer is a layer formed by joining a part of the gap layer with a part of the adhesive layer. Although the thickness in particular of the said intermediate | middle layer is not restrict | limited, For example, it is 1-1500 nm, 5-1000 nm, 10-800 nm, or 20-500 nm.

  The form of the laminated film of the present invention is not particularly limited, but the film shape is normal.

  The laminated film of the present invention is, for example, a roll body. Moreover, the laminated film of this invention may contain a resin film further as mentioned above, for example, and the said space | gap layer may be formed on the said long resin film. In this case, another long film may be laminated on the laminated film of the present invention, and another long resin film (for example, a composite film) is added to the laminated film of the present invention including the resin film and the gap layer. The paper may be in a form wound on a roll body after laminating paper, a release film, a surface protective film, and the like.

  Although the manufacturing method in particular of the laminated film of this invention is not restrict | limited, For example, the laminated film of the said this invention can be manufactured with the manufacturing method of this invention shown below.

[3. Manufacturing method of laminated film]
As described above, the method for producing a laminated film of the present invention is a method for producing a laminated film in which a void layer is laminated on a resin film. The method for producing the laminated film includes a coating step of coating the sol solution of the present invention on the resin film, and a drying step of drying the coated sol solution. In addition, unless otherwise indicated, the description of the laminated | multilayer film of the said invention can be used for the manufacturing method of this invention.

  Further, in the method for producing the laminated film, for example, a void layer, an intermediate layer, and an adhesive layer are laminated in the order, and the void layer and the adhesive layer are bonded by the intermediate layer. Alternatively, a method for producing a laminated film may be used. In this case, the method for producing the laminated film includes, for example, a void layer forming step for forming the void layer, an adhesive layer forming step for forming the adhesive layer on the void layer, and the void layer. And an intermediate layer forming step of reacting with the adhesive layer to form the intermediate layer. The gap layer forming step is not particularly limited. For example, as described later, the gap layer forming step may include the coating step, the drying step, and the bonding step, or include only the coating step and the drying step. You can leave.

  In the method for producing a laminated film of the present invention, for example, as described above, the void layer is a porous body in which silica porous particles are chemically bonded to each other. In the bonding step, the microporous particles ( Silica porous particles) are chemically bonded to each other. The method for producing a laminated film of the present invention further includes, for example, a step of producing a containing liquid containing the fine pore particles (silica porous particles) (containing liquid producing step) in addition to the coating step and the drying step. May be included.

  Below, the said liquid preparation process is demonstrated prior to description of each said process (a coating process, a drying process, etc.) first.

  The method for producing a laminated film of the present invention includes, for example, a containing liquid preparation step for producing a containing liquid containing the silica porous particles as described above. When the silica porous particles are a pulverized product of a gel compound, the pulverized product is obtained, for example, by pulverizing the gel compound. By the pulverization of the gel-like compound, as described above, the three-dimensional structure of the gel-like compound is destroyed and dispersed into the three-dimensional basic structure.

  Hereinafter, the production of the gel compound by gelation of the monomer compound and the preparation of a pulverized product by pulverization of the gel compound will be described with examples, but the present invention is not limited to the following examples.

  Gelation of the monomer compound can be performed, for example, by hydrogen bonding or intermolecular force bonding of the monomer compounds.

  Examples of the monomer compound include the silicon compound represented by the formula (1) described in the void layer of the present invention.

  Since the silicon compound of the formula (1) has a hydroxyl group, the monomers of the formula (1) can be hydrogen bonded or intermolecularly bonded through, for example, each hydroxyl group.

  Further, as described above, the silicon compound may be a hydrolyzate of the silicon compound precursor. For example, the silicon compound precursor represented by the formula (2) described in the void layer of the present invention, It may be produced by hydrolysis.

  The method for hydrolysis of the monomer compound precursor is not particularly limited, and can be performed, for example, by a chemical reaction in the presence of a catalyst. Examples of the catalyst include acids such as oxalic acid and acetic acid. In the hydrolysis reaction, for example, an aqueous solution of oxalic acid is slowly dropped and mixed in a mixed solution (for example, suspension) of the silicon compound and dimethyl sulfoxide in a room temperature environment, and then stirred for about 30 minutes. Can be done. When hydrolyzing the silicon compound precursor, for example, by completely hydrolyzing the alkoxy group of the silicon compound precursor, further heating and immobilization after gelation / aging / void structure formation, It can be expressed efficiently.

  The gelation of the monomer compound can be performed, for example, by a dehydration condensation reaction between the monomers. The dehydration condensation reaction is preferably performed, for example, in the presence of a catalyst. Examples of the catalyst include acid catalysts such as hydrochloric acid, oxalic acid, and sulfuric acid, and ammonia, potassium hydroxide, sodium hydroxide, ammonium hydroxide, and the like. And a dehydration condensation catalyst such as a base catalyst. The dehydration condensation catalyst is particularly preferably a base catalyst. In the dehydration condensation reaction, the amount of the catalyst added to the monomer compound is not particularly limited, and the catalyst is, for example, 0.1 to 10 mol, 0.05 to 7 mol, relative to 1 mol of the monomer compound, 0.1 to 5 mol.

  The gelation of the silicon compound is preferably performed in a solvent, for example. For example, one type of solvent may be used, or two or more types may be used in combination. Hereinafter, the solvent used for the gelation is also referred to as “gelling solvent”. As will be described later, when the gelled silicon compound is subjected to a grinding treatment after the gelling solvent is replaced with a grinding solvent, a solvent different from the grinding solvent is used as the gelling solvent. Specifically, for example, dimethyl sulfoxide (DMSO), N-methylpyrrolidone (NMP), N, N-dimethylacetamide (DMAc), dimethylformamide (DMF), γ-butyllactone (GBL), acetonitrile (MeCN), ethylene glycol ethyl ether (EGEE), or the like may be used. On the other hand, when the gelling solvent is used as the grinding solvent without replacing the gelling solvent with the grinding solvent, the same gelling solvent as the grinding solvent can be used.

  The gelation conditions are not particularly limited. The processing temperature with respect to the solvent containing the monomer compound is, for example, 20-30 ° C., 22-28 ° C., 24-26 ° C., and the processing time is, for example, 1-60 minutes, 5-40 minutes, 10-30. Minutes. When performing the said dehydration condensation reaction, the process conditions in particular are not restrict | limited, These illustrations can be used. By performing the gelation, for example, a siloxane bond grows, silica primary particles are formed, and further, the reaction proceeds, whereby the primary particles are linked in a bead shape to generate a three-dimensional gel. .

  The gel-like compound obtained by the gelation is preferably subjected to an aging treatment after the gelation reaction. By the aging treatment, for example, by further growing primary particles of a gel having a three-dimensional structure obtained by gelation, it is possible to increase the size of the particles themselves. The contact state of the contacting neck portion can be increased from point contact to surface contact. The gel subjected to the aging treatment as described above, for example, increases the strength of the gel itself, and as a result, can improve the strength of the three-dimensional basic structure after pulverization. Thereby, for example, in the drying step after applying the pulverized product, the pore size of the void structure in which the three-dimensional basic structure is deposited can be prevented from shrinking due to solvent volatilization during the drying process.

  The aging treatment can be performed, for example, by incubating the gel compound at a predetermined temperature for a predetermined time. The predetermined temperature is not particularly limited, and the lower limit thereof is, for example, 30 ° C or higher, 35 ° C or higher, 40 ° C or higher, and the upper limit thereof is, for example, 80 ° C or lower, 75 ° C or lower, 70 ° C or lower. The range is 30-80 degreeC, 35-75 degreeC, 40-70 degreeC, for example. The predetermined time is not particularly limited, and the lower limit thereof is, for example, 5 hours or more, 10 hours or more, 15 hours or more, and the upper limit thereof is, for example, 50 hours or less, 40 hours or less, 30 hours or less. The range is, for example, 5 to 50 hours, 10 to 40 hours, and 15 to 30 hours. Note that the optimum conditions for aging are mainly the conditions under which, for example, the increase in the silica primary particle size and the increase in the contact area of the neck portion can be obtained. Furthermore, it is preferable to consider the boiling point of the solvent being used. For example, if the aging temperature is too high, the solvent will be volatilized excessively, and the concentration of the coating liquid (gel solution) will increase, resulting in a three-dimensional void structure. There is a possibility that a problem such as closing of the pores of the liquid crystal will occur. On the other hand, for example, when the aging temperature is too low, not only the effect of the aging described above can be obtained sufficiently, but also the temperature variation over time of the mass production process increases, and there is a possibility that a product with poor quality can be produced. There is.

  In the aging treatment, for example, the same solvent as the gelation treatment can be used. Specifically, the aging treatment can be performed as it is on the reaction product after the gel treatment (that is, the solvent containing the gel compound). preferable. The number of moles of residual silanol groups contained in the gel (the gel-like compound, for example, the gel-like silicon compound) after the aging treatment after gelation is, for example, the added raw material (for example, the monomer compound precursor) When the number of moles of the alkoxy group is 100, the lower limit is, for example, 50% or more, 40% or more, 30% or more, and the upper limit is, for example, 1% or less, It is 3% or less, 5% or less, and the range is 1-50%, 3-40%, 5-30%, for example. For the purpose of increasing the hardness of the gel, for example, the lower the number of moles of residual silanol groups, the better. If the number of moles of silanol groups is too high, for example, there is a possibility that the void structure cannot be maintained before the precursor of the porous silicone material is crosslinked. On the other hand, if the number of moles of silanol groups is too low, for example, in the step of preparing the fine pore particle-containing liquid (for example, suspension) and / or the subsequent step, the pulverized product of the gel compound cannot be crosslinked, There is a possibility that sufficient film strength cannot be imparted. Although the above is an example of a silanol group, for example, when a silicon compound as a monomer is modified with various reactive functional groups, the same phenomenon can be applied to each functional group.

  After the monomer compound is gelled in the gelling solvent, the resulting gel compound is pulverized. In the pulverization, for example, the gel compound in the gelling solvent may be pulverized as it is, or after the gelation solvent is replaced with another solvent, A pulverization treatment may be applied to the gel compound. In addition, for example, when the catalyst used in the gelation reaction and the solvent used remain after the ripening process, causing the gelation of the liquid over time (pot life) and a decrease in the drying efficiency during the drying process, It is preferable to substitute the above solvent. Hereinafter, the other solvent is also referred to as a “grinding solvent”.

  The grinding solvent is not particularly limited, and for example, the organic solvent having a boiling point of 70 ° C. or higher and lower than 180 ° C. and a saturated vapor pressure at 20 ° C. of 15 kPa or lower can be used.

  By replacing the gelling solvent with the grinding solvent, for example, a more uniform coating film can be formed in the coating film formation described below.

  The method for pulverizing the gel compound is not particularly limited, and may be performed by, for example, an ultrasonic homogenizer, a high-speed rotation homogenizer, a pulverizer using other cavitation phenomenon, or a wet atomizer that obliquely collides liquids with each other at high pressure. Can do. A device for performing media grinding such as a ball mill physically destroys the void structure of the gel at the time of grinding, whereas a cavitation type grinding device preferable for the present invention such as a homogenizer is, for example, a gel-less system. The relatively weakly bonded silica particle bonding surface already contained in the three-dimensional structure is peeled off with a high shear force. Thereby, the obtained sol three-dimensional structure can hold, for example, a void structure having a certain range of particle size distribution, and can re-create the void structure by deposition during coating and drying. The conditions for the pulverization are not particularly limited. For example, it is preferable that the gel can be pulverized without volatilizing the solvent by instantaneously applying a high-speed flow. For example, it is preferable to grind so as to obtain a pulverized product having a particle size variation as described above (for example, a volume average particle size or a particle size distribution). If the amount of work such as pulverization time and strength is insufficient, for example, coarse grains remain and not only fine pores cannot be formed, but also appearance defects may increase and high quality may not be obtained. On the other hand, when the amount of work is excessive, for example, the sol particles become finer than the desired particle size distribution, and the void size deposited after coating and drying becomes fine, so that the desired void ratio (porosity) is not reached. there is a possibility.

  As described above, a liquid (for example, a suspension) containing the silica porous particles (crushed product of gel compound) can be produced. Furthermore, after the liquid containing the silica porous particles is produced or during the production process, the silica porous particles and the catalyst are contained by adding a catalyst for chemically bonding the silica porous particles to each other. A liquid can be produced. The catalyst may be, for example, a catalyst that promotes cross-linking between the microporous particles. As a chemical reaction for chemically bonding the fine pore particles, it is preferable to use a dehydration condensation reaction of residual silanol groups contained in silica sol molecules. By promoting the reaction between the hydroxyl groups of the silanol group with the catalyst, it is possible to form a continuous film that cures the void structure in a short time. Examples of the catalyst include a photoactive catalyst and a thermally active catalyst. According to the photoactive catalyst, for example, in the bonding step, the porous silica particles can be chemically bonded (for example, crosslinked) without being heated. According to this, for example, in the bonding step, since the entire void layer is unlikely to shrink, a higher porosity can be maintained. In addition to or instead of the catalyst, a substance that generates a catalyst (catalyst generator) may be used. For example, in addition to or instead of the photoactive catalyst, a substance that generates a catalyst by light (photocatalyst generator) may be used, or in addition to or instead of the thermally active catalyst A substance that generates water (thermal catalyst generator) may be used. The photocatalyst generator is not particularly limited, and examples thereof include a photobase generator (a substance that generates a basic catalyst by light irradiation), a photoacid generator (a substance that generates an acidic catalyst by light irradiation), and the like. A photobase generator is preferred. Examples of the photobase generator include 9-anthrylmethyl N, N-diethylcarbamate (trade name WPBG-018), (E) -1- [3- (2- Hydroxyphenyl) -2-propenoyl] piperidine ((E) -1- [3- (2-hydroxyphenyl) -2-propenoyl] piperidine, trade name WPBG-027), 1- (anthraquinone-2-yl) ethyl imidazolecarboxy Rate (1- (anthraquinon-2-yl) ethyl imidazolecarboxylate, trade name WPBG-140), 2-nitrophenylmethyl 4-methacryloyloxypiperidine-1-carboxylate (trade name WPBG-165), 1,2-diisopropyl- 3- [bis (dimethylamino) methylene] guanidinium 2- (3-benzoylphenyl) propionate (trade name WPBG-266), 1,2 -Dicyclohexyl-4,4,5,5-tetramethylbiguanidinium n-butyltriphenylborate (trade name WPBG-300), 2- (9-oxoxanthen-2-yl) propionic acid 1,5,7 -Triazabicyclo [4.4.0] dec-5-ene (manufactured by Tokyo Chemical Industry Co., Ltd.) and a compound containing 4-piperidinemethanol (trade name HDPD-PB100: manufactured by Heraeus). As described above, the trade names including the “WPBG” are trade names of Wako Pure Chemical Industries, Ltd. Examples of the photoacid generator include aromatic sulfonium salts (trade name SP-170: ADEKA), triarylsulfonium salts (trade name CPI101A: San Apro), and aromatic iodonium salts (trade name Irgacure 250: Ciba Japan). Company). Further, the catalyst for chemically bonding the silica porous particles to each other is not limited to the photoactive catalyst and the photocatalyst generator, and may be a thermal active catalyst such as urea or a thermal catalyst generator. Examples of the catalyst for chemically bonding the porous silica particles include base catalysts such as potassium hydroxide, sodium hydroxide and ammonium hydroxide, and acid catalysts such as hydrochloric acid, acetic acid and oxalic acid. Of these, base catalysts are preferred. The catalyst or catalyst generator that chemically bonds the porous silica particles is used, for example, by adding to the sol particle liquid (for example, suspension) containing the pulverized material (microporous particles) immediately before coating. Or a mixture of the catalyst or catalyst generator mixed with a solvent. The mixed liquid is, for example, a coating liquid dissolved by directly adding to the sol particle liquid, a solution in which the catalyst or catalyst generator is dissolved in a solvent, or a dispersion in which the catalyst or catalyst generator is dispersed in a solvent. But you can. The solvent is not particularly limited, and examples thereof include water, buffer solutions, and various organic solvents.

  The production method of the laminated film of the present invention can be carried out, for example, as follows using the sol solution (typically silica porous particle sol solution) produced as described above. Is not limited.

[Coating process]
First, a silica porous particle sol solution is coated on a resin film (hereinafter sometimes referred to as “base material”) (coating step). For the coating, for example, various coating methods described later can be used, and the present invention is not limited thereto. For example, a coating film containing the silica porous particles and the dispersion medium can be formed by directly applying the silica porous particle sol solution onto the resin film. The coating film can also be referred to as a coating layer, for example. In the following, the coating film (coating layer) may be referred to as an “uncrosslinked film”. By forming the coating film (uncrosslinked film), for example, the pulverized material in which the three-dimensional structure is destroyed settles and deposits, whereby a new three-dimensional structure is constructed. For example, the silica porous particle sol solution may not include a catalyst for chemically bonding the silica porous particles. For example, as described later, the bonding step may be performed after or while spraying a catalyst that chemically bonds the porous silica particles to the coating film (uncrosslinked film). However, the silica porous particle sol solution contains a catalyst that chemically bonds the silica porous particles to each other, and the silica porous material is caused by the action of the catalyst contained in the coating film (uncrosslinked film). The porous body (void layer) may be formed by chemically bonding particles.

  The dispersion medium (hereinafter also referred to as “coating solvent”) is, for example, as described above, an organic solvent having a boiling point of 70 ° C. or higher and lower than 180 ° C. and a saturated vapor pressure at 20 ° C. of 15 kPa or lower. including. Examples of the organic solvent include the organic solvents described above.

  In the coating step, for example, the sol-like pulverized material (hereinafter also referred to as “sol liquid”) dispersed in the dispersion medium is preferably applied onto the substrate. The silica porous particle sol solution of the present invention can continuously form a void layer having a film strength of a certain level or more by performing the chemical crosslinking after coating and drying on a substrate, for example. Is possible. The “sol” in the present invention refers to a state in which the silica sol particles having a nano three-dimensional structure retaining a part of the void structure are dispersed in a solvent and exhibit fluidity by pulverizing the three-dimensional structure of the gel. Say.

  The concentration of the pulverized product in the dispersion medium is not particularly limited, and is, for example, 0.3 to 50% (v / v), 0.5 to 30% (v / v), 1.0 to 10% (v / v). If the concentration of the pulverized product is too high, for example, the fluidity of the sol solution is significantly lowered, and there is a possibility of generating aggregates and coating streaks during coating. On the other hand, if the concentration of the pulverized product is too low, for example, not only does it take a considerable time to dry the dispersion medium of the sol solution, but also the residual dispersion medium immediately after drying becomes high, so the porosity (void Rate) may decrease.

  The physical properties of the sol are not particularly limited. The shear viscosity of the sol is, for example, a viscosity of 100 cPa · s or less, a viscosity of 10 cPa · s or less, and a viscosity of 1 cPa · s or less at a shear rate of 10001 / s. If the shear viscosity is too high, for example, coating streaks may occur, and problems such as a decrease in the transfer rate of gravure coating may be observed. On the other hand, when the shear viscosity is too low, for example, the wet coating thickness at the time of coating cannot be increased, and a desired thickness may not be obtained after drying.

The coating amount of the pulverized product on the substrate is not particularly limited, and can be appropriately set according to, for example, the desired thickness of the void layer (typically, a silicone porous body). As a specific example, when the void layer having a thickness of 0.1 to 1000 μm is formed, the amount of the pulverized material applied to the substrate is, for example, 0.01 to 60000 μg, 0 per 1 m ^{2 of the} substrate. .1 to 5000 μg, 1 to 50 μg. The preferable coating amount of the sol particle liquid is, for example, related to the concentration of the liquid, the coating method, etc., and thus it is difficult to define it uniquely. Is preferred. When there is too much application quantity, possibility that it will be dried with a drying furnace before a solvent volatilizes will become high, for example. As a result, the nano-ground sol particles settle and deposit in the solvent, and the solvent is dried before the void structure is formed, so that void formation is inhibited and the porosity (porosity) can be greatly reduced. There is sex. On the other hand, if the coating amount is too thin, there is a possibility that the risk of occurrence of coating repellency may increase due to unevenness of the base material, variation in hydrophilicity / hydrophobicity, or the like.

[Drying process]
Furthermore, the manufacturing method of this invention has a drying process which dries the coating film (non-crosslinked film | membrane) produced by applying the fine pore particle containing liquid as mentioned above, for example. By the drying process in the drying step, for example, not only the solvent (solvent contained in the sol particle liquid) in the coating film (uncrosslinked film) is removed, but also the sol particles are precipitated and dried during the drying process. The purpose is to deposit and form a void structure. The temperature of the drying treatment is, for example, 150 ° C. or less, 130 ° C. or less, 110 ° C. or less, and the drying treatment time is, for example, 0.1 to 30 minutes, 0.2 to 10 minutes, 0.3 to 3 minutes. The drying treatment temperature and time are preferably lower and shorter in relation to, for example, continuous productivity and high porosity (porosity). If the conditions are too strict, for example, when the substrate is a resin film, the substrate is extended in a drying furnace by being close to the glass transition temperature of the substrate, and formed immediately after coating. Defects such as cracks may occur in the void structure. On the other hand, if the conditions are too loose, for example, since the residual solvent is included at the time of leaving the drying furnace, there is a possibility that defects in appearance such as scratches will occur when rubbing with the roll in the next process. is there.

  The drying treatment may be, for example, natural drying, heat drying, or vacuum drying. The drying method is not particularly limited, and for example, a general heating means can be used. Examples of the heating means include a hot air fan, a heating roll, and a far infrared heater. Above all, when it is premised on industrial continuous production, it is preferable to use heat drying. Moreover, about the solvent used, the organic solvent whose boiling point is 70 degreeC or more and less than 180 degreeC and whose saturated vapor pressure in 20 degreeC is 15 kPa or less is mentioned.

[Join process]
Furthermore, in the method for producing a laminated film of the present invention, for example, the porous silica (void layer) is formed by chemically bonding the porous silica particles by the action of the catalyst (bonding step). Thereby, for example, the three-dimensional structure of the pulverized product in the coating film (uncrosslinked film) is fixed. When fixing by conventional sintering, for example, high temperature treatment at 200 ° C. or higher induces dehydration condensation of silanol groups and formation of siloxane bonds. In the present invention, by reacting various additives that catalyze the above dehydration condensation reaction, for example, a relatively low drying temperature of about 100 ° C. and several without causing damage to the base material (resin film), and several The void structure can be continuously formed and fixed in a short processing time of less than a minute.

  The method of chemically bonding is not particularly limited, and can be appropriately determined according to, for example, the type of the gel silicon compound. As a specific example, the chemical bonding can be performed by, for example, chemical cross-linking between the pulverized products, and, for example, inorganic particles such as titanium oxide are added to the pulverized product. In this case, it is conceivable to chemically cross-link the inorganic particles and the pulverized product. In addition, when a biocatalyst such as an enzyme is supported, a site other than the catalytic active site and the pulverized product may be chemically crosslinked. Therefore, the present invention can be applied to, for example, not only a void layer (silicone porous body) formed by the sol particles but also an organic-inorganic hybrid void layer, a host guest void layer, and the like, but is not limited thereto.

  The stage at which the chemical reaction (bonding step) in the presence of the catalyst is carried out (occurs) in the production method of the present invention is not particularly limited. For example, in the method for producing a laminated film of the present invention, the drying step may also serve as the bonding step. Further, for example, after the drying step, the bonding step of chemically bonding the microporous particles to each other by the action of the catalyst may be performed. For example, as described above, the catalyst may be a photoactive catalyst, and the porous body (void layer) may be formed by chemically bonding the fine pore particles by light irradiation in the bonding step. In addition, the catalyst may be a thermally active catalyst, and in the bonding step, the porous body (void layer) may be formed by chemically bonding the fine pore particles by heating.

The chemical reaction is performed, for example, by irradiating or heating the coating film containing the catalyst or the catalyst generator previously added to the sol solution, or by spraying the catalyst onto the coating film and then applying light. Irradiation or heating, or light irradiation or heating while spraying the catalyst or catalyst generator can be performed. Integrated light intensity in the light irradiation is not particularly limited, @ in 360nm terms, for ^{example, 200~800mJ} / cm ^2, a 250~600mJ / cm ² or 300~400mJ / cm ^2,. From the viewpoint of preventing the irradiation amount from being insufficient and the decomposition due to light absorption of the catalyst generator from proceeding and preventing the effect from becoming insufficient, an integrated light amount of 200 mJ / cm ² or more is good. Further, from the viewpoint of preventing the base material under the void layer from being damaged and generating thermal wrinkles, an integrated light amount of 800 mJ / cm ² or less is good. The conditions for the heat treatment are not particularly limited, and the heating temperature is, for example, 50 to 250 ° C., 60 to 150 ° C., 70 to 130 ° C., and the heating time is, for example, 0.1 to 30 minutes, 0.2 to 10 minutes and 0.3 to 3 minutes. Alternatively, the step of drying the sol solution (for example, suspension) applied as described above may also serve as the step of performing a chemical reaction in the presence of the catalyst. That is, in the step of drying the coated sol particle liquid (for example, suspension), the pulverized product (silica porous particles) may be chemically bonded to each other by a chemical reaction in the presence of the catalyst. good. In this case, the pulverized product (fine pore particles) may be further bonded to each other by further heating the coating film after the drying step. Furthermore, the chemical reaction in the presence of the catalyst may occur in the step of preparing the silica porous particle-containing liquid (for example, suspension) and the step of applying the silica porous particle-containing liquid. It is guessed. However, this assumption does not limit the present invention in any way. Moreover, about the solvent used, the organic solvent whose boiling point is 70 degreeC or more and less than 180 degreeC and whose saturated vapor pressure in 20 degreeC is 15 kPa or less is mentioned.

  As described above, a void layer can be formed on the resin film (gap layer forming step) to produce the laminated film of the present invention. However, the method for producing the laminated film of the present invention (method for forming the void layer) is not limited to this. For example, as described above, the drying step may also serve as the bonding step, or the gap layer forming step may be performed by performing only the coating step and the drying step without performing the bonding step.

[Strength improvement process]
In addition, the obtained void layer of the present invention may be subjected to a strength improving step (hereinafter, also referred to as “aging step”) in which the strength is improved by, for example, heat aging. For example, the adhesive peel strength of the void layer of the present invention with respect to the resin film on which the void layer of the present invention is laminated can be improved by the strength improving step (aging step). In the said strength improvement process (aging process), you may heat the space | gap layer (typically silicone porous body) of this invention, for example. The temperature in the aging step is, for example, 40 to 80 ° C, 50 to 70 ° C, or 55 to 65 ° C. The reaction time is, for example, 5 to 30 hr, 7 to 25 hr, or 10 to 20 hr. In the aging step, for example, by lowering the heating temperature, the adhesive peel strength can be improved while suppressing the shrinkage of the void layer, and both high porosity and strength can be achieved.

  Although the phenomenon and mechanism that occur in the strength improving step (aging step) are unknown, for example, the catalyst contained in the void layer of the present invention further promotes chemical bonding (for example, cross-linking reaction) between the pulverized products. This is considered to improve the strength. As a specific example, when the void layer of the present invention is a porous silicone body and residual silanol groups (OH groups) are present in the porous silicone body, the residual silanol groups are considered to be chemically bonded to each other by a crosslinking reaction. It is done. The catalyst contained in the void layer of the present invention is not particularly limited. For example, the catalyst used in the bonding step may be used, or the photobase generating catalyst used in the bonding step may be basic generated by light irradiation. The substance and the acidic substance etc. which generate | occur | produced by light irradiation may be sufficient as the photoacid generation catalyst used at the said coupling | bonding process. However, this description is an example and does not limit the present invention.

[Adhesive layer formation process]
Next, for example, the adhesive layer may be formed on the gap layer (adhesive layer forming step). This step is not particularly limited. For example, the adhesive layer may be formed by applying (coating) a pressure-sensitive adhesive or an adhesive onto the gap layer. In addition, the adhesive layer is formed on the gap layer by bonding the adhesive layer side of the adhesive tape or the like on which the adhesive layer is laminated on the base material. You may do it. In this case, the base material such as the adhesive tape may be left as it is or may be peeled off from the adhesive layer. In addition, the laminated | multilayer film of this invention may or may not contain arbitrary components other than the said resin film, the said space | gap layer, the said intermediate | middle layer, and the said adhesive layer suitably. The optional component is, for example, a layer other than the resin film, the void layer, the intermediate layer, and the adhesive layer, and may be a base material such as the adhesive tape, for example.

[Intermediate layer forming process]
Furthermore, for example, the gap layer may be reacted with the adhesive layer to form the intermediate layer (intermediate layer forming step). This step is not particularly limited. For example, as described above, the intermediate layer may be formed by reacting by heating the void layer and the adhesive layer. The temperature of the reaction is, for example, 40 to 80 ° C, 50 to 70 ° C, or 55 to 65 ° C. The reaction time is, for example, 5 to 30 hr, 7 to 25 hr, or 10 to 20 hr.

  By forming the intermediate layer, for example, the void layer of the present invention and the adhesive layer are difficult to peel off. The reason (mechanism) is unknown, but is presumed to be due to, for example, the throwing property (throwing effect) of the intermediate layer. The anchoring property (an anchoring effect) is that the interface is firmly fixed in the vicinity of the interface between the void layer and the intermediate layer because the intermediate layer is embedded in the void layer. A phenomenon (effect). However, this reason (mechanism) is an example of a presumed reason (mechanism), and does not limit the present invention. The reaction between the void layer and the adhesive layer is not particularly limited, and may be a reaction by catalytic action, for example. The catalyst may be, for example, a catalyst contained in the void layer of the present invention. Specifically, for example, the catalyst used in the coupling step may be used, the photobase generation catalyst used in the coupling step is a basic substance generated by light irradiation, and the photoacid generation catalyst used in the coupling step is light. An acidic substance generated by irradiation may be used. The reaction between the void layer and the adhesive layer may be, for example, a reaction (for example, a crosslinking reaction) in which a new chemical bond is generated.

  Moreover, as will be described later, the intermediate layer forming step may also serve as a step of improving the strength of the void layer. The mechanism by which the strength of the void layer is improved by the intermediate layer forming step is unknown, but is estimated as follows, for example. That is, in the intermediate layer forming step, the intermediate layer is formed by applying energy to the void layer and the adhesive layer, for example, by heating to cause a reaction. It is considered that the energy of the heating or the like increases the number of crosslinks (chemical bonds) inside the void layer and improves the strength of the void layer. Further, this reaction proceeds, for example, by the action of a catalyst contained in the void layer. However, these are examples of mechanisms that can be estimated and do not limit the present invention.

  In the bonding step, for example, the pore layer is formed by chemically bonding the microporous particles by a catalytic reaction using a photobase generator. For example, when the base catalyst generated from the photobase generator remains in the precursor, chemical bonding (for example, cross-linking) between the microporous particles by heating in the intermediate layer forming step or the like. Reaction) further proceeds. This is considered to improve the strength of the void layer. As a specific example, when the fine pore particles are fine pore particles of a silicon compound (for example, a crushed product of a gel-like silica compound), and residual silanol groups (OH groups) are present in the void layer, the residual silanol It is thought that the groups are chemically bonded by a crosslinking reaction. However, this description is also an example and does not limit the present invention.

  The mechanism by which the intermediate layer is formed is also unclear. For example, when the void layer reacts with the adhesive layer by the action of a catalyst present in the void layer, the intermediate layer is formed. Guessed. The catalyst present in the void layer is not particularly limited, and may be, for example, a basic catalyst or an acidic catalyst. The base catalyst is not particularly limited. For example, the photobase generator may be a basic catalyst generated by light irradiation. The acid catalyst is not particularly limited, but for example, the photoacid generator may be an acidic catalyst generated by light irradiation. Further, as described above, the reaction between the void layer and the adhesive layer may be, for example, a reaction in which a new chemical bond is generated (for example, a crosslinking reaction).

  Further, for example, as described above, the intermediate layer forming step may also serve as a strength improving step for improving the strength of the void layer. In the strength improving step, for example, a crosslinking reaction is caused inside the void layer. Thereby, for example, the strength of the gap layer is improved, the film strength is further improved, and the gap film and the adhesive layer are difficult to peel off. At this time, the crosslinking reaction that occurs in the void layer proceeds, for example, by the action of the catalyst contained in the void layer as described above. However, this description does not limit the present invention.

[Winding process]
For example, the laminated film is a rolled laminated film roll, and further includes a winding step of winding the laminated film in which the gap layer is laminated on the resin film to form the laminated film roll. But you can.

  As described above, the method for producing a laminated film of the present invention can be performed. The laminated film produced by the production method of the present invention can be made into, for example, a roll-shaped porous body, and has advantages such as good production efficiency and easy handling.

  The laminated film (gap layer) of the present invention thus obtained may be laminated with another film (layer), for example, to form a laminated structure including the gap layer. In this case, in the laminated structure, each component may be laminated via, for example, a pressure-sensitive adhesive or an adhesive.

  For example, since the lamination of each constituent element is efficient, the lamination may be performed by continuous processing using a long film (so-called Roll to Roll, etc.). May be laminated with batch processing.

  The resin film may be a long resin film, and the coating step and the drying step may be continuously performed on the long resin film.

  Hereinafter, a method for forming the void layer of the present invention on a substrate (resin film) will be described with reference to FIGS. About FIG. 2, after forming the said space | gap layer, although the process of bonding and winding up a protective film is shown, when performing lamination | stacking on another functional film, you may use said method. Then, after coating and drying another functional film, it is possible to bond the void layer on which the film has been formed just before winding. The illustrated film forming method is merely an example, and the present invention is not limited thereto.

  The substrate may be the resin film described above in the description of the laminated film of the present invention. In this case, the void layer of the present invention is obtained by forming the void layer on the substrate. Moreover, after forming the said void layer on the said base material, the said void layer is laminated | stacked on the resin film mentioned above in description of the void layer of this invention, and the void layer of this invention is obtained.

  FIG. 1 is a cross-sectional view schematically showing an example of a process in the method for forming the void layer of the present invention on the substrate. In FIG. 1, the void layer is formed by coating the substrate 10 with the coating step (1) for applying the sol solution 20 ″ of the present invention, and drying the paint 20 ″. The coating film forming step (drying step) (2) for forming the coating film 20 ′, which is a precursor layer, and chemical treatment (for example, cross-linking treatment) on the coating film 20 ′, the void layer 20 is formed. A chemical treatment step (3) to be formed. The chemical treatment step (3) corresponds to, for example, the “bonding step” in which chemical crosslinking is performed inside the coating film 20 ′. In such a case, hereinafter, the chemical treatment step (bonding step) (3) may also be referred to as “crosslinking step (3)” or simply “crosslinking step”. In this way, the void layer 20 can be formed on the base material 10 as shown. In addition, the formation method of the said space | gap layer may include processes other than the said process (1)-(3) suitably, and does not need to include it.

  In the coating step (1), the coating method of the sol solution 20 ″ is not particularly limited, and a general coating method can be adopted. Examples of the coating method include a slot die method, a reverse gravure coating method, a micro gravure method (micro gravure coating method), a dip method (dip coating method), a spin coating method, a brush coating method, a roll coating method, and flexographic printing. Method, wire bar coating method, spray coating method, extrusion coating method, curtain coating method, reverse coating method and the like. Among these, the extrusion coating method, the curtain coating method, the roll coating method, the micro gravure coating method and the like are preferable from the viewpoints of productivity, coating film smoothness, and the like. The coating amount of the sol solution 20 ″ is not particularly limited, and can be set as appropriate so that the thickness of the void layer 20 is appropriate, for example. The thickness of the gap layer 20 is not particularly limited, and is as described above, for example.

  In the drying step (2), the sol solution 20 ″ is dried (that is, the dispersion medium contained in the paint 20 ″ is removed) to form a coating film (precursor layer) 20 ′. The conditions for the drying treatment are not particularly limited and are as described above.

  Further, in the chemical treatment step (3), the coating film 20 ′ containing the catalyst (for example, photoactive catalyst, photocatalyst generator, thermal active catalyst such as KOH, or thermal catalyst generator) added before coating. On the other hand, the void layer 20 is formed by light irradiation or heating to chemically bond (for example, crosslink) the pulverized materials in the coating film (precursor) 20 ′. The light irradiation or heating conditions in the chemical treatment step (3) are not particularly limited and are as described above.

  Next, FIG. 2 schematically shows an example of a slot die coating apparatus and a method for forming the void layer using the same. Although FIG. 2 is a cross-sectional view, hatching is omitted for easy viewing.

  As shown in the drawing, each step in the method using this apparatus is performed while the substrate 10 is conveyed in one direction by a roller. A conveyance speed is not specifically limited, For example, it is 1-100 m / min, 3-50 m / min, 5-30 m / min.

  First, a coating process (1) for coating the base material 10 with the sol solution 20 '' is performed on the coating roll 102 while the base material 10 is fed out and conveyed from the feed roller 101, and then the oven zone 110 is applied. The process proceeds to the drying step (2). In the coating apparatus of FIG. 2, a preliminary drying process is performed after a coating process (1) and prior to a drying process (2). The preliminary drying step can be performed at room temperature without heating. In the drying step (2), the heating means 111 is used. As the heating means 111, as described above, a hot air fan, a heating roll, a far infrared heater, or the like can be used as appropriate. Further, for example, the drying step (2) may be divided into a plurality of steps, and the drying temperature may be increased as the subsequent drying step is performed.

  After the drying step (2), a chemical treatment step (crosslinking step) (3) is performed in the chemical treatment zone 120. In the chemical treatment step (3), for example, when the dried coating film 20 ′ includes a photoactive catalyst, light irradiation is performed by lamps (light irradiation means) 121 disposed above and below the base material 10. Alternatively, for example, when the coating film 20 ′ after drying contains a thermally active catalyst, a hot air fan 121 disposed above and below the substrate 10 using a hot air fan (heating means) instead of the lamp (light irradiation device) 121. To heat the substrate 10. This cross-linking treatment causes chemical bonding between the pulverized products in the coating film 20 ′, and the void layer 20 is cured and strengthened. In this example, the chemical treatment step (3) is performed after the drying step (2). As described above, at which stage of the production method of the present invention the chemical bond between the pulverized products is caused. Is not particularly limited. For example, as described above, the drying step (2) may also serve as the chemical treatment step (3). Further, even when the chemical bond occurs in the drying step (2), the chemical treatment step (3) may be further performed to further strengthen the chemical bond between the pulverized products. In addition, in the step prior to the drying step (2) (for example, a preliminary drying step, a coating step (1), a step of preparing a coating liquid (for example, a suspension), etc.) Bonding may occur. Then, after the chemical treatment step (3), the laminated body in which the gap layer 20 is formed on the substrate 10 is wound up by the winding roll 105. For example, by using the resin film as the base material 10, the gap layer 20 can be laminated directly on the resin film (base material 10). In FIG. 2, the gap layer 20 of the laminate is covered and protected with a protective sheet fed from the roll 106. Here, instead of the protective sheet, another layer formed of a long film may be laminated on the gap layer 20.

  FIG. 3 schematically shows an example of a micro gravure method (micro gravure coating method) coating apparatus and a method for forming the void layer using the same. In addition, although the figure is sectional drawing, the hatch is abbreviate | omitted for legibility.

  As shown in the figure, each step in the method using this apparatus is performed while the substrate 10 is conveyed in one direction by a roller, as in FIG. A conveyance speed is not specifically limited, For example, it is 1-100 m / min, 3-50 m / min, 5-30 m / min.

  First, a coating process (1) for coating the base material 10 with the sol solution 20 ″ while feeding the base material 10 from the feed roller 201 and carrying it is performed. The sol solution 20 ″ is applied using a liquid reservoir 202, a doctor (doctor knife) 203, and a micro gravure 204 as shown in the figure. Specifically, the sol solution 20 ″ stored in the liquid reservoir 202 is attached to the surface of the microgravure 204, and further, the surface of the substrate 10 is controlled by the microgravure 204 while being controlled to a predetermined thickness by the doctor 203. Apply to. The microgravure 204 is merely an example, and the present invention is not limited to this, and any other coating means may be used.

  Next, a drying process (2) is performed. Specifically, as shown in the figure, the base material 10 coated with the sol solution 20 ″ is conveyed into the oven zone 210, and heated by the heating means 211 in the oven zone 210, so that the sol solution 20 ″ is heated. dry. The heating means 211 may be the same as that shown in FIG. Further, for example, by dividing the oven zone 210 into a plurality of sections, the drying step (2) may be divided into a plurality of steps, and the drying temperature may be increased as the subsequent drying step is performed. After the drying step (2), the chemical treatment step (3) is performed in the chemical treatment zone 220. In the chemical treatment step (3), for example, when the dried coating film 20 ′ includes a photoactive catalyst, light irradiation is performed by lamps (light irradiation means) 221 disposed above and below the substrate 10. Alternatively, for example, when the coating film 20 ′ after drying contains a thermally active catalyst, a hot air fan (heating means) is used instead of the lamp (light irradiation device) 221 and is arranged below the base material 10 ( The substrate 10 is heated by the heating means 221. By this crosslinking treatment, the pulverized material in the coating film 20 ′ is chemically bonded to each other, and the void layer 20 is formed.

  Then, after the chemical treatment step (3), the laminate in which the porous structure 20 is formed on the substrate 10 is wound up by the winding roll 251. As the base material 10, for example, by using the resin film, the gap layer 20 can be directly laminated on the resin film (base material 10). Thereafter, for example, another layer may be laminated on the laminate. Further, before the laminate is taken up by the take-up roll 251, for example, another layer may be laminated on the laminate.

  4 to 6 show another example of the continuous treatment process in the method for forming the void layer of the present invention. As shown in the cross-sectional view of FIG. 4, this method is performed except that a chemical treatment step (for example, a crosslinking treatment step) (3) for forming the void layer 20 is followed by a strength improving step (aging step) (4). The method shown in FIGS. As shown in FIG. 4, in the strength improving step (aging step) (4), the strength of the void layer 20 is improved to obtain a void layer 21 with improved strength. The strength improving step (aging step) (4) is not particularly limited, and is as described above, for example.

  FIG. 5 is a schematic view showing another example of the slot die coating apparatus and the method for forming the void layer using the slot die coating apparatus. As shown in the drawing, this coating apparatus has a strength improving zone (aging zone) 130 for performing a strength improving step (aging step) (4) immediately after the chemical processing zone 120 for performing the chemical processing step (3). Is the same as the apparatus of FIG. That is, after the chemical treatment step (3), the strength improvement step (aging step) (4) is performed in the strength improvement zone (aging zone) 130 to improve the adhesive peel strength of the void layer 20 to the resin film 10, The void layer 21 with improved adhesive peel strength is formed. The strength improving step (aging step) (4) may be performed, for example, by heating the air gap layer 20 as described above using the hot air fans (heating means) 131 disposed above and below the base material 10. Although heating temperature, time, etc. are not specifically limited, For example, it is as above-mentioned. Thereafter, similarly to FIG. 3, the laminated film in which the gap layer 21 is formed on the substrate 10 is wound up by the winding roll 105.

  FIG. 6 is a schematic diagram showing another example of the coating apparatus of the micro gravure method (micro gravure coating method) and the method of forming the porous structure using the same. As shown in the drawing, this coating apparatus has a strength improving zone (aging zone) 230 for performing a strength improving step (aging step) (4) immediately after the chemical processing zone 220 for performing chemical processing step (3). Is the same as the apparatus of FIG. That is, after the chemical treatment step (3), the strength improvement step (aging step) (4) is performed in the strength improvement zone (aging zone) 230 to improve the adhesive peel strength of the void layer 20 to the resin film 10, The void layer 21 with improved adhesive peel strength is formed. The strength improving step (aging step) (4) may be performed, for example, by heating the void layer 20 as described above using the hot air blowers (heating means) 231 disposed above and below the base material 10. Although heating temperature, time, etc. are not specifically limited, For example, it is as above-mentioned. Thereafter, similarly to FIG. 3, the laminated film in which the gap layer 21 is formed on the substrate 10 is wound up by the winding roll 251.

  Moreover, another example of the continuous processing process in the method of forming the void layer of the present invention is shown in FIGS. As shown in the cross-sectional view of FIG. 7, this method is an adhesive process in which an adhesive layer 30 is applied on the void layer 20 after a chemical treatment step (for example, a crosslinking step) (3) for forming the void layer 20. A layer coating step (adhesive layer forming step) (4) and an intermediate layer forming step (5) in which the gap layer 20 is reacted with the adhesive layer 30 to form the intermediate layer 22 are included. Except for these, the method of FIGS. 7 to 9 is the same as the method shown in FIGS. In FIG. 7, the intermediate layer forming step (5) also serves as a step of improving the strength of the void layer 20 (strength improving step), and after the intermediate layer forming step (5), the void layer 20 The void layer 21 is improved. However, this invention is not limited to this, For example, the space | gap layer 20 does not need to change after an intermediate | middle layer formation process (5). The adhesive layer coating step (adhesive layer forming step) (4) and the intermediate layer forming step (5) are not particularly limited, and are as described above, for example.

  FIG. 8 is a schematic view showing still another example of the coating apparatus of the slot die method and the method of forming the void layer using the same. As shown in the figure, this coating apparatus has an adhesive layer coating zone 130a for performing the adhesive layer coating step (4) immediately after the chemical processing zone 120 for performing the chemical processing step (3). Is the same as the apparatus of FIG. In the same figure, the intermediate layer forming zone (aging zone) 130 disposed immediately after the adhesive layer coating zone 130a is obtained by the hot air blower (heating means) 131 disposed above and below the base material 10, and the strength of FIG. The same heat treatment as in the improvement zone (aging zone) 130 can be performed. That is, in the apparatus of FIG. 8, after the chemical treatment step (3), an adhesive or an adhesive is applied onto the void layer 20 by the adhesive layer coating means 131a in the adhesive layer coating zone 130a. (Coating) Then, the adhesive layer coating process (adhesive layer forming process) (4) for forming the adhesive layer 30 is performed. Further, as described above, instead of application (coating) of the pressure-sensitive adhesive or adhesive, bonding (sticking) such as a pressure-sensitive adhesive tape having the adhesive layer 30 may be used. Further, an intermediate layer forming step (aging step) (5) is performed in the intermediate layer forming zone (aging zone) 130, and the void layer 20 and the adhesive layer 30 are reacted to form the intermediate layer 22. Further, as described above, in this step, the void layer 20 becomes the void layer 21 with improved strength. Although the heating temperature, time, etc. by the hot air fan (heating means) 131 are not specifically limited, For example, it is as above-mentioned.

  FIG. 9 is a schematic view showing still another example of a coating apparatus of a micro gravure method (micro gravure coating method) and a method for forming the porous structure using the same. As shown in the figure, this coating apparatus has an adhesive layer coating zone 230a for performing the adhesive layer coating step (4) immediately after the chemical processing zone 220 for performing the chemical processing step (3). Is the same as the apparatus of FIG. In the same figure, the intermediate layer forming zone (aging zone) 230 disposed immediately after the adhesive layer coating zone 230a is obtained from the strength shown in FIG. The same heat treatment as that of the improvement zone (aging zone) 230 can be performed. That is, in the apparatus of FIG. 9, after the chemical treatment step (3), an adhesive or an adhesive is applied onto the void layer 20 by the adhesive layer coating means 231a in the adhesive layer coating zone 230a. (Coating) Then, the adhesive layer coating process (adhesive layer forming process) (4) for forming the adhesive layer 30 is performed. Further, as described above, instead of application (coating) of the pressure-sensitive adhesive or adhesive, bonding (sticking) such as a pressure-sensitive adhesive tape having the adhesive layer 30 may be used. Further, an intermediate layer forming step (aging step) (5) is performed in the intermediate layer forming zone (aging zone) 230, and the void layer 20 and the adhesive layer 30 are reacted to form the intermediate layer 22. Further, as described above, in this step, the void layer 20 becomes the void layer 21 with improved strength. The heating temperature, time, and the like by the hot air fan (heating means) 231 are not particularly limited, and are as described above, for example.

  And after intermediate body formation process (aging process) (5), the laminated | multilayer film in which the space | gap layer 21 was formed on the base material 10 are wound up with the winding roll 251. FIG. Thereafter, for example, another layer may be laminated on the laminated film. Further, before the laminated film is taken up by the take-up roll 251, for example, another layer may be laminated on the laminated film.

[4. Optical member]
As described above, the optical member of the present invention includes the laminated film of the present invention. The optical member of the present invention is characterized by including the laminated film of the present invention, and other configurations are not limited at all. The optical member of the present invention may further include other layers in addition to the laminated film of the present invention, for example.

  Moreover, the optical member of this invention contains the laminated film of the said this invention as a low reflection layer, for example. The optical member of the present invention may further include other layers in addition to the laminated film of the present invention, for example. The optical member of the present invention has a roll shape, for example.

[5. Image display device]
As described above, the image display device of the present invention includes the optical member of the present invention. The image display device of the present invention is characterized by including the optical member of the present invention, and other configurations are not limited at all. The image display device of the present invention may further include other configurations in addition to the optical member of the present invention, for example.

  Next, examples of the present invention will be described. However, the present invention is not limited to the following examples.

(Reference Example 1)
A silicon compound gel (gel silicon compound) was produced as described below, and further aged.

(1) Gelation of silicon compound 0.95 g of MTMS which is a precursor of a silicon compound was dissolved in 2.2 g of DMSO. To the mixed solution, 0.5 g of 0.01 mol / L oxalic acid aqueous solution was added and stirred at room temperature for 30 minutes to hydrolyze MTMS to produce tris (hydroxy) methylsilane.

  After adding 0.38 g of 28% ammonia water and 0.2 g of pure water to 5.5 g of DMSO, the hydrolyzed mixture was further added and stirred at room temperature for 15 minutes. Then, tristris (hydroxy) methylsilane was gelated to obtain a gel silicon compound.

(2) Aging treatment The mixture solution that had been subjected to the gelation treatment was incubated at 40 ° C. for 20 hours as it was to be aged.

Example 1
A porous particle sol solution was produced as described below, and a laminated film roll (high porosity film roll) in which a high porosity film was laminated on an acrylic base material was obtained. That is, first, the aging-treated gel-like silicon compound obtained from Reference Example 1 was immersed in isobutyl alcohol, and solvent substitution was performed until the amount of DMSO in the gel reached 0.02 g / ml. Thereafter, the gel was pulverized using an ultrasonic homogenizer to obtain a sol solution (porous particle sol solution) containing silica porous particles and a dispersion medium (isobutyl alcohol). 0.031 g of WPBG266 (Wako: photobase generator) isobutyl alcohol solution with a concentration of 1.5% and bis (trimethoxysilyl) ethane (TCI) isobutyl alcohol solution with a concentration of 5% with respect to 0.75 g of the sol solution 0.018 g was added to obtain a coating solution. Subsequently, the coating solution was continuously applied and heat-dried on a roll-shaped acrylic substrate using a slot die to obtain a high porosity film having a film thickness of 1 μm in a roll shape. After 1000 m of continuous coating, the presence or absence of precipitation of particles at the lip portion of the subsequent die was confirmed. Moreover, the external appearance of the high porosity film | membrane in that case was confirmed. The evaluation results are shown in Table 1 described later.

(Example 2)
Except that isobutyl alcohol described in Example 1 was changed to 1-pentanol, the same operation as in Example 1 was performed to obtain a porous particle sol solution and a laminated film roll (high porosity film roll).

(Comparative Example 1)
Except that isobutyl alcohol described in Example 1 was changed to n-hexane, the same operation as in Example 1 was performed to obtain a porous particle sol solution and a laminated film roll (high porosity film roll).

(Comparative Example 2)
Except for changing the isobutyl alcohol described in Example 1 to methanol, the same operation as in Example 1 was performed to obtain a porous particle sol solution and a laminated film roll (high porosity membrane roll).

(Comparative Example 3)
Except for changing the isobutyl alcohol described in Example 1 to acetone, the same operation as in Example 1 was performed to obtain a porous particle sol solution and a laminated film roll (high porosity film roll).

  About each of the laminated film roll (high porosity membrane roll) of Examples 1-2 and Comparative Examples 1-3, the refractive index and the porosity were measured by the above-mentioned method. Moreover, about each of the laminated film roll (high-porosity film | membrane roll) of Example 2 and Comparative Examples 1-3, particle precipitation and the high porosity film | membrane external appearance were observed visually similarly to Example 1. FIG. The results are shown in Table 1 below together with the type of the dispersion medium, the saturated vapor pressure at 20 ° C., and the boiling point.

  As shown in Table 1, each of the high porosity films produced using the porous particle sol solutions of the examples has a high porosity (porosity), no particle precipitation, and an excellent appearance. Was. On the other hand, in Comparative Examples 1 to 3 in which the boiling point of the dispersion medium was less than 70 ° C., particle precipitation occurred and the appearance was poor. In particular, in Comparative Examples 1 and 3 in which the saturated vapor pressure at 20 ° C. of the dispersion medium exceeded 15 kPa, the appearance was too bad to measure the porosity and the refractive index. That is, Comparative Examples 1 and 3 were extremely poor in transparency (translucency) and could not be put into practical use as an optical film.

  As described above, the sol liquid (for example, silica porous particle sol liquid) of the present invention includes the dispersoid (for example, silica porous particles) and a dispersion medium, and for example, coating using the sol liquid. By forming a film, a porous structure having voids can be produced. Thus, the porous structure formed using the sol liquid can exhibit the same function as the air layer described above, for example. Further, as described above, since the dispersion medium contains an organic solvent having a boiling point of 70 ° C. or higher and lower than 180 ° C. and a saturated vapor pressure at 20 ° C. of 15 kPa or lower, the resulting porous structure is It is possible to form a void layer having a high porosity (porosity), improving production efficiency, and having an excellent appearance. For this reason, the said porous structure can provide a silanol porous body to various objects easily and simply. Specifically, the porous structure of the present invention can be used as, for example, a heat insulating material, a sound absorbing material, a regenerative medical scaffold, a dew condensation preventing material, an optical member, an image display device, etc., instead of an air layer. Therefore, the production method of the present invention and the silica porous particle sol solution obtained thereby are useful, for example, in the production of the porous structure as described above.

10 Base material (resin film)
20 Porous structure (void layer)
20 'coating film (precursor layer)
20 '' sol solution 21 porous structure with improved strength (void layer)
22 Intermediate layer 30 Adhesive layer 101 Delivery roller 102 Coating roll 110 Oven zone 111 Hot air (heating means)
120 Chemical treatment zone 121 Lamp (light irradiation means) or hot air device (heating means)
130a Adhesive layer coating zone 130 Intermediate formation zone 131a Adhesive layer coating unit 131 Hot air blower (heating unit) 105 Winding roll 106 Roll 201 Feeding roller 202 Liquid reservoir 203 Doctor (doctor knife)
204 Microgravure 210 Oven zone 211 Heating means 220 Chemical treatment zone 221 Lamp (light irradiation means) or hot air blower (heating means)
230a Adhesive layer coating zone 230 Intermediate formation zone 231a Adhesive layer application unit 231 Hot air (heating unit)
251 Winding roll

Claims (9)

A sol solution containing a dispersoid and a dispersion medium,
The sol liquid, wherein the dispersion medium contains an organic solvent having a boiling point of 70 ° C. or higher and lower than 180 ° C. and a saturated vapor pressure at 20 ° C. of 15 kPa or lower. The sol solution according to claim 1, wherein the dispersoid is at least one selected from the group consisting of porous particles, fibrous substances, and tabular substances. The said dispersion medium is a dispersion medium containing 20-100 mass% of said organic solvents whose boiling point is 70 degreeC or more and less than 180 degreeC, and whose saturated vapor pressure in 20 degreeC is 15 kPa or less. The sol liquid described. The sol solution according to any one of claims 1 to 3, wherein a high porosity film or a high porosity film roll having a porosity of 40% or more can be obtained by heat drying at a temperature of 150 ° C or lower. .   The sol solution according to any one of claims 1 to 4, wherein the porous particles include silica porous particles.   6. The fibrous material according to claim 1, wherein the fibrous material is at least one fibrous material selected from the group consisting of cellulose nanofibers, alumina nanofibers, chitin nanofibers, and chitosan nanofibers. Sol solution. The sol solution according to any one of claims 1 to 6, wherein a concentration of the dispersoid in the sol solution is 0.3 wt% or more and 15 wt% or less. The sol solution according to any one of claims 1 to 7, wherein the dispersoid is a pulverized product of a gel, and the pulverized product of the gel is dispersed in an organic solvent that is a dispersion medium. A method for producing a high-porosity film or a high-porosity film roll having a porosity of 40% or more, comprising a step of heat-drying the sol solution according to any one of claims 1 to 8 at a temperature of 150 ° C or lower.

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