JP2014044079A - Evaluation method for transparent composite sheet, transparent composite sheet product, and transparent composite sheet - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an evaluation method for a transparent composite sheet.SOLUTION: In one or more embodiments, a method for evaluating a transparent composite sheet comprising a transparent resin and particles is provided, which uses at least one of an average inter-particle distance (A) of closest particles and the standard deviation thereof of the particles in the transparent composite sheet and an average number (B) of the closest particles and the standard deviation thereof. The average inter-particle distance (A) of closest particles is obtained in the process of extracting a structure factor from a scattering intensity spectrum by the measurement of small-angle X-ray scattering, carrying out a reverse Monte Carlo simulation to output particle coordinates, a structure factor S'(q) and a radial distribution function g(r), obtaining an inter-particle distance that gives a maximum value at the first peak in the radial distribution function g(r), and determining the inter-particle distance as an average inter-particle distance. The average number (B) of the closest particles is a number of particles present in the range from the average particle diameter of the particles to the first minimum of the radial distribution function g(r).

Description

  The present disclosure relates to a method for evaluating a transparent composite sheet, a transparent composite sheet product, and a transparent composite sheet.

  As a color-forming sheet that utilizes principles other than coloring by absorbing some light, such as pigments, pigments, dyes, etc., there is a transparent composite sheet that utilizes the structural color of colloidal microcrystals of spherical nanoparticles (patent) Literatures 1-3).

  Patent Document 1 discloses a transparent composite sheet containing 0.1 to 70% by volume of spherical nanoparticles having an average primary particle size of 15 to 400 nm in a transparent resin.

  Patent Document 2 discloses a transparent composite sheet containing 5 to 50% by volume of silica particles having an average primary particle diameter of 50 to 250 nm in a transparent resin. Patent Document 3 further discloses that, in a scattering intensity spectrum obtained by a small-angle X-ray scattering method using synchrotron radiation X-rays, the number of peaks due to particle shape is 5 or more, and the average interparticle distance Discloses a transparent composite sheet having a thickness of 100 to 220 nm.

  Patent Document 3 discloses a transparent composite sheet in which spherical particles having an average primary particle size of 50 to 200 nm are contained in a transparent resin in an amount of 5 to 40% by volume, and an average interparticle distance is 100 to 300 nm.

JP 2010-111805 A JP 2011-84659 A JP 2011-190335 A

  The present disclosure provides a method for evaluating a transparent composite sheet.

In one aspect, the present disclosure provides a transparent composite sheet comprising a transparent resin and particles, the average inter-particle distance (A) of the closest particles of the particles in the transparent composite sheet and its standard deviation, and the closest The present invention relates to a method for evaluation using at least one of the average number of particles (B) and its standard deviation. In the evaluation method according to the present disclosure, the average interparticle distance (A) of the closest particles and the average number (B) of the closest particles are calculated by performing the following 1) to 4).
1) obtaining a scattering intensity spectrum of the transparent composite sheet sample by small-angle X-ray scattering measurement;
2) extracting the structure factor S (q) from the scattering intensity spectrum;
3) Reverse Monte Carlo simulation is performed using the structure factor S (q), and particle coordinates, structure factor S ′ (q), and radial distribution function g (r) are obtained as outputs;
4) Obtaining the value of the interparticle distance that gives the maximum value of the first peak of the radial distribution function g (r) as the average interparticle distance (A) of the nearest particle, and / or the average particle of the particle A value obtained by calculating from the particle coordinates the number of particles existing in the range from the diameter to the first minimum of the radial distribution function g (r) is obtained as the average number (B) of the closest particles.

  In one aspect, the present disclosure provides a transparent composite sheet containing a transparent resin and particles, an average interparticle distance (A) of the closest particles of the particles in the transparent composite sheet and its standard deviation, and The present invention relates to a transparent composite sheet product including at least one piece of information on the average number (B) of contacting particles and its standard deviation. In the transparent composite sheet product according to the present disclosure, the average interparticle distance (A) of the closest particles and the average number (B) of the closest particles can be calculated by performing the above 1) to 4).

  In one aspect, the present disclosure is a transparent composite sheet including a transparent resin and particles, wherein the average primary particle diameter of the particles is 50 to 200 nm, and the average interparticle distance (A ) Relates to a transparent composite sheet having a thickness of 100 to 300 nm. In another aspect, the present disclosure is a transparent composite sheet including a transparent resin and particles, wherein the average primary particle size of the particles is 50 to 200 nm, and the average number of closest particles (B) However, the present invention relates to 6 to 20 transparent composite sheets. In the transparent composite sheet according to the present disclosure, the average interparticle distance (A) of the nearest particles and the average number (B) of the nearest particles can be calculated by performing the above 1) to 4).

  According to the present disclosure, in one or a plurality of embodiments, a method for evaluating a transparent composite sheet can be provided. According to the present disclosure, in one or a plurality of embodiments, the three-dimensional arrangement of particles in the transparent composite sheet, that is, the three-dimensional structure of the particles can be evaluated.

FIG. 1 is an example of a scattering intensity profile obtained by performing small-angle X-ray scattering measurement of a sample optical sheet. FIG. 2 is an example of the extracted structure factor S (q). FIG. 3 is an example of the corrected structure factor S ′ (q). FIG. 4 is an example of the coordinate position of the particle obtained by the reverse Monte Carlo simulation. FIG. 5 is an example of a radial distribution function g (r) obtained by reverse Monte Carlo simulation.

  The present disclosure can evaluate the three-dimensional arrangement of particles in the transparent composite sheet by reverse Monte Carlo simulation, that is, the three-dimensional structure of the particles, and the evaluation of the three-dimensional structure of the particles is not limited to one or more embodiments. For example, it is based on the knowledge that it can be used as an index indicating the optical characteristics of the transparent composite sheet.

[Transparent composite sheet]
In the present disclosure, the “transparent composite sheet” refers to a sheet containing a transparent resin and particles, and in one or a plurality of non-limiting embodiments, light having a specific wavelength can be emitted while being transparent under light irradiation. It is a transparent composite sheet that produces structural color. In one or a plurality of non-limiting embodiments, the transparent composite sheet of the present disclosure can be produced by curing and / or crosslinking a composite resin composition including a resin material and particles. In the transparent composite sheet according to the present disclosure, in one or a plurality of embodiments, the total light transmittance of the transparent composite sheet (thickness: 200 μm) in the D65 standard light source is 60% or more, 70% or more, 80% or more, 85 % Or more sheets. As this measuring method, for example, a method defined in JIS K 7361-1 (a test method for the total light transmittance of a plastic-transparent material) can be mentioned.

[Resin material]
The resin material is the transparent resin, and in one or a plurality of non-limiting embodiments, (meth) acrylate, epoxy compound, glycidyl type epoxy resin, alicyclic epoxy resin, oxetane compound, oxetanyl group And the like, vinyl ether compounds and the like. Since these resin materials have particularly high transparency, they are suitable as resin materials used for transparent composite sheets.

（式（１）中、Ｒ¹およびＲ²は、互いに異なっていてもよく、水素原子またはメチル基である。ａは１または２であり、ｂは０または１である。）

As the (meth) acrylate, for example, (meth) acrylate having an alicyclic structure and having two or more functional groups is preferable in terms of heat resistance and linear expansion coefficient. In one or a plurality of non-limiting embodiments, such a (meth) acrylate is at least one selected from the following general formula (1) and general formula (2) from the viewpoint of heat resistance and transparency ( And (meth) acrylate.

(In Formula (1), R ¹ and R ² may be different from each other and are a hydrogen atom or a methyl group. A is 1 or 2, and b is 0 or 1.)

Among the (meth) acrylates represented by the general formulas (1) and (2), at least one acrylate selected from the general formulas (1) and (2) is preferable from the viewpoint of reactivity and thermal stability. The general formula (1) is a dicyclopentadienyl diacrylate having a structure in which R ¹ and R ² are hydrogen, a is 1 and b is 0 in one or a plurality of non-limiting embodiments. It is. In one or more non-limiting embodiments, the general formula (2) is perhydro-1 having a structure in which X is —CH ₂ OCOCH═CH ₂ , R ³ and R ⁴ are hydrogen, and P is 1. , 4; 5,8-dimethanonaphthalene-2,3,7- (oxymethyl) triacrylate and acrylate having a structure in which X, R ³ and R ⁴ are all hydrogen and P is 0 or 1 At least one acrylate selected. In view of viscosity and the like, the general formula (2) is preferably norbornane dimethylol diacrylate having a structure in which X, R ³ and R ⁴ are all hydrogen and P is 0. In addition, the (meth) acrylate shown by General formula (2) can be obtained by the well-known method shown, for example in Unexamined-Japanese-Patent No. 5-70523.

  Examples of glycidyl type epoxy resins include bisphenol A type epoxy resins, bisphenol F type epoxy resins, bisphenol S type epoxy resins, naphthalene type epoxy resins or hydrogenated products thereof, epoxy resins having a dicyclopentadiene skeleton, and triglycidyl isocyanate. Examples thereof include an epoxy resin having a nurate skeleton, an epoxy resin having a cardo skeleton, and an epoxy resin having a polysiloxane structure.

  Examples of the alicyclic epoxy resin include 3,4-epoxycyclohexylmethyl-3 ′, 4′-epoxycyclohexanecarboxylate, 1,2,8,9-diepoxylimonene, and ε-caprolactone oligomer at both ends. , 4-epoxycyclohexylmethanol and 3,4-epoxycyclohexanecarboxylic acid ester-bonded, a hydrogenated biphenyl skeleton, and an alicyclic epoxy resin having a hydrogenated bisphenol A skeleton.

  In one or more embodiments, the content of the resin material in the composite resin composition is preferably 50 to 70% by volume and more preferably 50 to 60% by volume from the viewpoint of improving transparency.

[Initiator]
When the composite resin composition is cured by active energy rays such as ultraviolet rays, it is preferable to include a photopolymerization initiator that generates radicals, cations, and the like in the composite resin composition. The photopolymerization initiator as a radical generator may be, in one or more non-limiting embodiments, benzophenone, benzoin methyl ether, benzoin propyl ether, diethoxyacetophenone, 1-hydroxy-cyclohexyl-phenyl ketone, 2,6-dimethylbenzoyl. Diphenylphosphine oxide and 2,4,6-trimethylbenzoyldiphenylphosphine oxide. The photoinitiator as a cation generator is an aromatic sulfonium salt and an aromatic iodonium salt in one or a plurality of non-limiting embodiments. Two or more of these photopolymerization initiators may be used in combination.

  The content of the photopolymerization initiator in the composite resin composition may be an amount that is appropriately cured, and in one or more embodiments that are not limited, the organic component 100 containing a functional group in the resin composition. The lower limit is 0.01 parts by weight or more, 0.02 parts by weight or more, or 0.1 parts by weight or more with respect to parts by weight, and the upper limit is 2 parts by weight or less, 1 part by weight or less, or 0.5 parts by weight or less. It is.

  When heat-polymerizing the composite resin composition by heating, a thermal polymerization initiator can be contained in the resin composition as necessary. The thermal polymerization initiator as the radical generator is, in one or more non-limiting embodiments, benzoyl peroxide, diisopropyl peroxycarbonate, t-butyl peroxy (2-ethylhexanoate). Examples of the thermal polymerization initiator as the cation generator include, but are not limited to, aromatic sulfonium salts, aromatic iodonium salts, ammonium salts, aluminum chelates, and boron trifluoride amine complexes.

  The content of the thermal polymerization initiator in the composite resin composition may be an amount that is appropriately cured, and in one or more embodiments without limitation, an organic component containing a functional group in the composite resin composition 4 parts by weight or less, or 3 parts by weight or less with respect to 100 parts by weight.

〔particle〕
In one or a plurality of non-limiting embodiments, the particles are silica (silicon oxide) particles or semiconductor particles.

  Examples of the silica include colloidal silica. Examples of the organic solvent in which the colloidal silica is dispersed include alcohols, ketones, esters, and glycol ethers in one or a plurality of non-limiting embodiments. Among these, alcohol-based organic solvents such as methanol, ethanol, isopropyl alcohol, butyl alcohol, and n-propyl alcohol, and ketone-based organic solvents such as methyl ethyl ketone and methyl isobutyl ketone are preferable because of easy solvent removal. Isopropyl alcohol is more preferable from the viewpoint that the viscosity of the raw material is reduced because the viscosity after solvent removal is lower than that of other solvent systems, and the composite resin composition can be stably produced.

  In one or more embodiments, the silica particles may be surface-treated with a coupling agent such as a silane coupling agent or a titanate coupling agent. Moreover, the composite resin composition may contain a coupling agent.

  The semiconductor particle is a particle having a property of emitting light having a wavelength inversely proportional to a difference between two energy levels by absorbing energy such as light or an electron beam. In one or a plurality of embodiments, the semiconductor particle is not limited thereto. , Particles containing chalcogenides. In one or a plurality of embodiments, the chalcogenide includes chalcogens (of group VI elements of the periodic table, oxygen (O), sulfur (S), selenium (Se), tellurium (Te), polonium (Po)). A compound containing 5 elements), a group II-VI compound that is a compound of a group II element and a group VI element of the periodic table, or at least selected from ZnS, CdS, ZnSe, CdSe, ZnTe, CdTe, ZnO One type.

  In order to increase the color development efficiency, the semiconductor particles are preferably formed by uniformly dispersing semiconductor ultrafine particles having a particle size smaller than twice the Bohr radius in the matrix without aggregation. Various inorganic substances and organic substances can be used for the matrix. Examples of inorganic substances include silicon compounds. Examples of the organic material include polyimide and a resin having an alicyclic structure from the viewpoint of heat resistance. A coupling agent containing silicon or titanium in the matrix can also be used.

  The content of the particles (hereinafter, also referred to as “particle filling amount”) is not limited, and in one or more embodiments, from the viewpoint of producing a composite transparent sheet that exhibits structural color development while maintaining transparency. 5-40 volume% of the said composite resin composition is preferable, and 20-40 volume% is more preferable.

  In one or a plurality of non-limiting embodiments, the average primary particle size of the particles is preferably 15 nm or more, more preferably 50 nm or more, and even more preferably 80 nm or more from the viewpoint of suppressing increase in viscosity. Moreover, it is 400 nm or less, 200 nm or less, and 120 nm or less from the point of transparency maintenance. In the present disclosure, the average particle diameter of primary particles refers to that measured by a small angle X-ray scattering method unless otherwise specified. More specifically, the average particle diameter of specific primary particles refers to that measured by the methods described below and in the examples.

  In one or more embodiments that are not limited, the refractive index difference between the transparent resin and the particles in the transparent composite sheet is preferably 0.1 or less or 0.05 or less from the viewpoint of improving transparency. .

[Other ingredients]
In the composite resin composition, a thermoplastic or thermosetting oligomer or polymer can be used in combination as necessary. If necessary, a small amount of fillers such as antioxidants, ultraviolet absorbers, dyes and pigments and other inorganic fillers, as long as the properties such as transparency, solvent resistance, liquid crystal resistance, and heat resistance are not impaired. Etc. may be included.

[Method for producing composite resin composition]
A method for producing a composite resin composition using a resin composition containing a resin material and colloidal silica as particles includes the following three methods in one or more embodiments that are not limited.
(1) A method of removing an organic solvent by mixing colloidal silica dispersed in an organic solvent, a resin composition, and other blends and, if necessary, reducing the pressure while stirring.
(2) A method in which colloidal silica dispersed in an organic solvent is mixed with a resin composition and other compounds, and after removing the solvent as necessary, casting and further removing the solvent.
(3) A method in which powdered silica particles are mixed with a resin composition and other blends and dried by using a mixing apparatus having a high dispersion ability.

[Method for producing transparent composite sheet]
In one or a plurality of embodiments that are not limited, the transparent composite sheet can be produced by forming the composite composition into a sheet shape and curing and / or crosslinking the obtained molded body with heat, light, or the like. In one or a plurality of non-limiting embodiments, the forming method is a method of casting the composite composition and drying it as necessary, or a desired sheet between a glass plate, a plastic plate, a metal plate, etc. having surface smoothness. In this method, the spacer is sandwiched so that the thickness is obtained, and the composite composition is sandwiched. The method of curing and / or cross-linking the molded body includes, in one or a plurality of non-limiting embodiments, a method of curing with active energy rays, a method of thermal polymerization by applying heat, or a method of using these in combination.

[Evaluation of transparent composite sheet]
In one or a plurality of embodiments, the present disclosure provides a transparent composite sheet containing a transparent resin and particles, an average interparticle distance (A) of the closest particles of the particles in the transparent composite sheet, and a standard deviation thereof, Further, the present invention relates to a method for evaluation using at least one of the average number (B) of the closest particles and its standard deviation.

In the present disclosure, the average interparticle distance (A) of the closest particles and the average number (B) of the closest particles are calculated by performing the following 1) to 4).
1) The small angle X-ray scattering of the transparent composite sheet sample is measured to obtain the scattering intensity spectrum,
2) Extracting the structure factor S (q) from the scattering intensity spectrum,
3) Reverse Monte Carlo simulation is performed using the structure factor S (q), and particle coordinates, structure factor S ′ (q), and radial distribution function g (r) are obtained as outputs.
4) The value of the interparticle distance giving the maximum value of the first peak of the radial distribution function g (r) is obtained as the average interparticle distance (A) of the closest particles. And / or the value obtained by calculating from the particle coordinates the number of particles existing in the range from the average particle size of the particles to the first minimum of the radial distribution function g (r) is the average number of closest particles (B ) Get as.

[Small angle X-ray scattering measurement (SAXS)]
As conditions for the small-angle X-ray scattering measurement of the transparent composite sheet sample, in one or a plurality of embodiments, the X-ray energy is 6 keV or more, 8 keV or more, or 12 keV or more from the viewpoint of obtaining a scattering spectrum used in RMC analysis. Is preferred. Examples of the wavelength of the X-ray include 2.0 to 1.0 mm, and in one or more embodiments that are not limited, the wavelength is 1.5 to 1.0 mm.

  The X-ray used for the small-angle X-ray scattering measurement is synchrotron radiation X-ray in one or a plurality of embodiments. Synchrotron radiation X-rays can emit X-rays having a single color and high directivity in the energy range as described above. Synchrotron synchrotron radiation X-rays are synchrotron radiation facilities such as SPring-8 of the High-Intensity Optical Science Research Center, PF Ring of the High Energy Accelerator Research Organization, UVSOR of the Molecular Science Research Institute, HiSOR of the Hiroshima University Synchrotron Radiation Research Center Can be used. Note that the X-rays used for the small-angle X-ray scattering measurement are not necessarily limited to the synchrotron radiation X-rays as long as the high-energy X-rays as described above can be used.

  In one or a plurality of embodiments, the camera length in the small-angle X-ray scattering measurement is preferably 4000 mm or more, and more preferably 6000 mm or more from the viewpoint of obtaining a scattering spectrum used in RMC analysis. The upper limit of the camera length is 160 m or less, or 16000 mm or less in one or more embodiments.

  In one or a plurality of embodiments, the X-ray wavelength in the small-angle X-ray scattering measurement is preferably 0.5 to 2.0 mm (0.05 to 0.20 nm) from the viewpoint of obtaining a scattering spectrum used in RMC analysis. More preferably, it is 1.0-1.7cm, More preferably, it is 1.3-1.6cm, More preferably, it is 1.4-1.6cm, More preferably, it is 1.5cm.

  The detector in the small angle X-ray scattering measurement is a two-dimensional X-ray detector in one or more embodiments that are not limited.

[Reverse Monte Carlo (RMC) simulation]
The reverse Monte Carlo (RMC) simulation is performed using three pieces of information: a) a structural factor calculated from the scattering spectrum obtained by the small-angle X-ray scattering measurement, b) a particle size, and c) a number density of the particles. . Reverse Monte Carlo simulation is performed in one or more embodiments without limitation, RMCA, RMC ++, using RMC _{_} POT ++, and software such as RMCProfile. RMC ++ and RMC _{_} POT ++ is available in the "http://www.szfki.hu/~nphys/rmc++/opening.html" at the time of the June 2012, RMCprofile is, at the time of the June 2012 it is available in the "http://www.rmcprofile.org/Main _{_} Pag".

[A. (Structural factor)
The structure factor used for the RMC simulation is a structure obtained by removing a shape factor (a factor reflecting the shape of the particle) from the scattering spectrum obtained by the small-angle X-ray scattering measurement in one or a plurality of non-limiting embodiments. Factor S (q). Further, the structural factor used for the RMC simulation may be a structural factor S (q) obtained by further correcting the structural factor S (q) in one or a plurality of non-limiting embodiments.

The structural factor S (q) is extracted as follows in one or a plurality of non-limiting embodiments. That is, the scattering profile of a transparent composite sheet sample with a low particle filling amount (hereinafter also referred to as a “low filling sample”) is considered to contain no interparticle interference, and the scattering profile of the low filling sample is shaped. It is extracted by subtracting it as a factor and further normalizing with a value when the scattering vector q is sufficiently large.
Scattering intensity = structural factor S (q) × form factor P (q) × constant low filling amount The particle content of the sample may be 0.001 to 1% by volume in one or more embodiments without limitation. Specifically, the structural factor S (q) can be extracted by a method described in Examples described later.

  The structure factor S (q) may be a corrected structure factor S (q) if necessary. For example, the form factor may not be completely removed by the above-mentioned subtraction alone, or the contribution of background scattering may remain. In one or a plurality of non-limiting embodiments, if a peak is seen at the same position where the peak derived from the shape factor appeared, it is determined that the shape factor has not been completely removed and correction is performed. . In one or more other non-limiting embodiments, if the structure factor S (q), which should converge to 1 as q increases, oscillates without converging even when q increases, the background It is determined that the contribution of scattering and the influence of the slits of the apparatus remain, and correction is performed. The correction of the structure factor can be corrected using calculation simulation software for correction in one or a plurality of non-limiting embodiments. Examples of the software include, but are not limited to, MCGR (software developed by McGreevy and Pusztai).

[B. (Average particle diameter)
The average particle size of particles used for RMC simulation is to fit the theoretical scattering profile of a perfect sphere with respect to the scattering profile after the second peak where the influence of the shape factor is small from the scattering spectrum obtained by the small angle X-ray scattering measurement. It can be calculated by It can also be obtained by observing, with an electron microscope or the like, a material obtained by applying particles as a raw material on a substrate or a composite sheet filled with particles, and directly measuring the particle size from the observed particle image. Further, it can be obtained by diluting the raw material particles in an appropriate organic solvent and evaluating with a dynamic light scattering measurement device. Among these, the average particle diameter of particles used for RMC simulation is preferably an average particle diameter measured by small-angle X-ray scattering measurement from the viewpoint of quoting the structure factor from the result of X-ray scattering. In addition, when measuring an average particle diameter by small angle X-ray scattering measurement, it is preferable from a viewpoint of accuracy that the filling amount of the particle | grains contained in a transparent composite sheet sample shall be 0.01-1 volume%.

[C. (Number density of particles)
The number density of the particles used for the RMC simulation can be calculated from the particle filling amount and the average particle diameter of the particles. Specifically, it can be calculated by the method described in the examples. In one or a plurality of embodiments, the particle filling amount can be calculated from the charged amount, or can be measured by thermogravimetry. From the point of accuracy, the particle filling amount is preferably a value obtained by thermogravimetry.

  By performing RMC simulation using the above a) structure factor, b) average particle size of particles, and c) number density of particles, particle coordinates, structure factor S ′ (q), and radius A distribution function g (r) can be obtained.

[Average distance between nearest particles (A)]
In the present disclosure, the average interparticle distance (A) of the closest particles refers to the value of the interparticle distance that gives the maximum value of the first peak of the radial distribution function g (r).

  The average interparticle distance (A) according to the present disclosure has an advantage that three-dimensional information can be more accurately evaluated. For example, the average interparticle distance obtained by observing the transparent composite sheet with an electron microscope (such as SEM) is information on a part of the sample such as the surface, that is, information on a local observation site. Therefore, there is a possibility that the information is not necessarily information that gives the characteristics of the entire system. Furthermore, the average interparticle distance based on information from two-dimensional observation has a problem that three-dimensional information may not be correctly evaluated. On the other hand, the average interparticle distance (A) according to the present disclosure is a value that reflects information on the structure of a sufficiently large region as compared with the observation range of an electron microscope (such as SEM), and the three-dimensional particle arrangement. It has the advantage that it is a value reflecting the information. Therefore, according to the average interparticle distance (A) according to the present disclosure, the transparent composite sheet can be more accurately evaluated in one or a plurality of embodiments.

  The average interparticle distance (A) according to the present disclosure can be associated with the presence or absence of color developability of the transparent composite sheet for structural color development in one or a plurality of non-limiting embodiments. Therefore, if the average interparticle distance (A) according to the present disclosure is used, a transparent composite sheet for the purpose of structural color development can be evaluated.

  In one or a plurality of non-limiting embodiments, when evaluating a transparent composite sheet for the purpose of structural color development, in which a transparent composite sheet having an average particle size of 50 to 200 nm is evaluated, the average according to the present disclosure If the interparticle distance (A) is, for example, 100 to 300 nm or 100 to 200 nm, it can be determined that the color development and the transparency are suitable.

[Standard deviation of average interparticle distance (A) of nearest neighbor particles]
The evaluation of the transparent composite sheet according to the present disclosure uses a standard deviation of the average interparticle distance (A) in addition to or instead of the average interparticle distance (A) according to the present disclosure in one or a plurality of non-limiting embodiments. be able to. The standard deviation of the average interparticle distance (A) is such that the intercenter distance is within r1 for all particles present in the system, with the value r1 of r giving the first minimum of the radial distribution function g (r) as a threshold value. The distribution of the distance between the centers of the combinations of the particles existing in the center is used as a population, and can be obtained by performing numerical calculation.

  The standard deviation of the average interparticle distance (A) according to the present disclosure can be associated with the transparency of the transparent composite sheet for the purpose of structural color development and the sharpness of color development in one or more embodiments without limitation. Therefore, if the standard deviation of the average interparticle distance (A) according to the present disclosure is used, a transparent composite sheet for the purpose of structural color development can be evaluated.

  In one or a plurality of non-limiting embodiments, when evaluating a transparent composite sheet for the purpose of structural color development, in which a transparent composite sheet having an average particle size of 50 to 200 nm is evaluated, the average according to the present disclosure When the standard deviation of the interparticle distance (A) is, for example, 0 to 32 nm, it can be determined that it is suitable for achieving both vividness of color development and transparency.

[Average number of closest particles (B)]
In the present disclosure, the average number (B) of closest particles is calculated from the particle coordinates by calculating the number of particles existing in the range from the average particle size of the particles to the first minimum of the radial distribution function g (r). Value. Specifically, with the value r1 of r giving the first minimum of the radial distribution function g (r) as a threshold, the number of particles whose center-to-center distance is within r1 with respect to all particles present in the system. The average number (B) according to the present disclosure can be calculated by counting and taking the number average based on the number of particles. It can be said that the average number (B) according to the present disclosure indicates the regularity of the particle arrangement.

  The average number (B) and / or the standard deviation thereof according to the present disclosure can be related to the transparency of a transparent composite sheet intended for structural color development and the sharpness of color development in one or more embodiments without limitation. Therefore, if the average number (B) and / or its standard deviation according to the present disclosure is used, a transparent composite sheet for the purpose of structural color development can be evaluated. Note that the standard deviation of the average number (B) is such that the center-to-center distance is within r1 for all particles existing in the system, with the value r1 of r giving the first minimum of the radial distribution function g (r) as a threshold value. It can be obtained by counting the number of existing particles and performing a numerical calculation using the distribution of the number of adjacent particles as a population.

  In one or a plurality of non-limiting embodiments, when evaluating a transparent composite sheet for the purpose of structural color development, in which a transparent composite sheet having an average particle size of 50 to 200 nm is evaluated, If the average number (B) of the contact particles is, for example, 6 to 20, or 12 to 18, it can be determined that it is suitable for both color development and transparency.

  In one or a plurality of non-limiting embodiments, when evaluating a transparent composite sheet for the purpose of structural color development, in which a transparent composite sheet having an average particle size of 50 to 200 nm is evaluated, If the standard deviation of the average number (B) of the contact particles is, for example, 0 to 1.2, it can be determined that it is suitable for both color development and transparency.

[Evaluation method of transparent composite sheet]
In one or a plurality of embodiments, the present disclosure is a method for evaluating a transparent composite sheet, the average inter-particle distance (A) of the closest particle of the transparent composite sheet to be evaluated and its standard deviation, and the closest particle The present invention relates to an evaluation method including measuring at least one of an average number (B) and a standard deviation thereof. According to the evaluation method of the present disclosure, the evaluation of the three-dimensional structure of the particles in the transparent composite sheet can be evaluated in one or more non-limiting embodiments, and in one or more other non-limiting embodiments, At least one of the average interparticle distance (A) and the standard deviation thereof, and the average number of closest particles (B) and the standard deviation thereof can be used as an index indicating the optical properties of the transparent composite sheet.

[Transparent composite sheet products]
In one or a plurality of embodiments, the present disclosure is a transparent composite sheet product of a transparent composite sheet including a transparent resin and particles, and the average inter-particle distance of nearest particles of the particles in the transparent composite sheet ( It relates to a transparent composite sheet product comprising A) and its standard deviation, and at least one information of the average number of closest particles (B) and its standard deviation. The average interparticle distance (A) of the closest particles and the average number (B) of the closest particles are as described above. The transparent composite sheet product according to the present disclosure includes, in one or a plurality of non-limiting embodiments, the information described in the packaging of the transparent composite sheet, and the information is enclosed in the packaging of the transparent composite sheet. A form in which the information is described in an advertisement or catalog of the transparent composite sheet (including written and online), and the information is printed, stamped, attached, and pasted on a part of the transparent composite sheet It may include a form selected from among the forms.

[Electronic component boards]
The present disclosure relates to a transparent composite sheet product according to the present disclosure, and an electronic component substrate that includes the transparent composite sheet subjected to the transparent composite sheet evaluation method according to the present disclosure. In one or more embodiments, the electronic component substrate is not limited to a transparent plate, an optical lens, an optical disk substrate, a liquid crystal display element plastic substrate, a color filter substrate, an organic EL display element plastic substrate, a solar cell substrate, and a touch panel. , Optical elements, optical waveguides and the like.

That is, the present disclosure may relate to one or more of the following embodiments;
[1] A transparent composite sheet containing a transparent resin and particles is measured by using the average inter-particle distance (A) of the closest particles of the particles in the transparent composite sheet and its standard deviation, and the average number of closest particles ( B) and an evaluation method using at least one of the standard deviation thereof, wherein the average interparticle distance (A) of the nearest particles and the average number (B) of the nearest particles are 1) to Evaluation method of transparent composite sheet calculated by 4);
1) obtaining a scattering intensity spectrum of the transparent composite sheet sample by small-angle X-ray scattering measurement;
2) extracting the structure factor S (q) from the scattering intensity spectrum;
3) Reverse Monte Carlo simulation is performed using the structure factor S (q), and particle coordinates, structure factor S ′ (q), and radial distribution function g (r) are obtained as outputs;
4) Obtaining the value of the interparticle distance that gives the maximum value of the first peak of the radial distribution function g (r) as the average interparticle distance (A) of the nearest particle, and / or the average particle of the particle A value obtained by calculating from the particle coordinates the number of particles existing in the range from the diameter to the first minimum of the radial distribution function g (r) is obtained as the average number (B) of the closest particles.
[2] A transparent composite sheet product,
A transparent composite sheet comprising a transparent resin and particles, and
Information of at least one of the average interparticle distance (A) of the closest particles of the particles in the transparent composite sheet and the standard deviation thereof, and the average number (B) of the closest particles and the standard deviation thereof,
A transparent composite sheet product in which the average interparticle distance (A) of the closest particles and the average number (B) of the closest particles are calculated by the following 1) to 4);
1) obtaining a scattering intensity spectrum of the transparent composite sheet sample by small-angle X-ray scattering measurement;
2) extracting the structure factor S (q) from the scattering intensity spectrum;
3) Reverse Monte Carlo simulation is performed using the structure factor S (q), and particle coordinates, structure factor S ′ (q), and radial distribution function g (r) are obtained as outputs;
4) Obtaining the value of the interparticle distance that gives the maximum value of the first peak of the radial distribution function g (r) as the average interparticle distance (A) of the nearest particle, and / or the average particle of the particle A value obtained by calculating from the particle coordinates the number of particles existing in the range from the diameter to the first minimum of the radial distribution function g (r) is obtained as the average number (B) of the closest particles.
[3] A transparent composite sheet containing a transparent resin and particles,
The average primary particle size of the particles is 60 to 200 nm,
The transparent composite sheet whose average interparticle distance (A) of the nearest particle | grains obtained by the evaluation method of Claim 1 is 100-300 nm;
[4] A transparent composite sheet containing a transparent resin and particles,
The average primary particle size of the particles is 60 to 200 nm,
The transparent composite sheet whose average number (B) of the nearest particle | grains obtained by the evaluation method of Claim 1 is 6-20 pieces;
[5] A substrate for electronic parts manufactured using the transparent composite sheet product according to [2] or the transparent composite sheet according to [3] or [4].

  Hereinafter, the present disclosure will be described in more detail by way of examples. However, these examples are illustrative, and the present disclosure is not limited to these examples.

1. Sample preparation [Sample optical sheet having a particle diameter of 120 nm and a particle filling amount of 33% by volume: Production Example 1]
(Preparation of composite composition)
Norbornane dimethylol diacrylate (TO-2111; manufactured by Toagosei Co., Ltd.) 5 parts by weight, γ-acryloxypropylmethyldimethoxysilane (KBM-5102; manufactured by Shin-Etsu Chemical Co., Ltd.) 1 part by weight, isopropyl alcohol-dispersed colloidal silica 20 Part by weight (silica content 30% by weight, average particle size 120 nm, IPA-ST-ZL; manufactured by Nissan Chemical Co., Ltd.) was blended, and volatile components were removed under reduced pressure while stirring at 40 ° C. Thereafter, 0.03 parts by weight of 1-hydroxy-cyclohexyl-phenyl-ketone (Irgacure 184 manufactured by Ciba Specialty Chemicals) was added and dissolved as a photopolymerization initiator, and then the volatile components were removed under reduced pressure to obtain a composite. A composition was obtained. The solvent content in the prepared composite composition was less than 10%. Moreover, the refractive index difference between the transparent resin used and the silica particles was 0.1 or less.

[Sheet]
The obtained composite composition is heated in an oven at a predetermined temperature (60 to 80 ° C.), poured into a 0.4 mm-thick frame formed on the glass plate, and the glass plate is placed on the glass plate from above. The composite composition was filled. The composite composition sandwiched between the glass plates was cured by irradiating with UV light of about 500 mJ / cm ² from both sides, and the sheet was peeled from the glass. Each sheet peeled from the glass was heated at about 100 ° C. for 3 hours in a vacuum oven, and further heated at about 275 ° C. for 3 hours to obtain a sample optical sheet.

(Filling amount measurement)
About the prepared sample optical sheet, thermogravimetry was performed and the particle filling rate was measured. When the filling rate of the silica particles was determined from the weight of the residue after heating the sample optical sheet at 400 ° C. for 1 hour, the volume fraction (filling amount) of the silica particles was 33% by volume.

[Preparation of optical sheet having particle size of 120 nm, low filling amount (0.1% by volume): Production Example 2]
Preparation Example 1 except that 5 parts by weight of norbornane dimethylol diacrylate, 1 part by weight of γ-acryloxypropylmethyldimethoxysilane, and 0.04 part by weight of isopropyl alcohol-dispersed colloidal silica were used in Preparation Example 1. In the same manner as above, an optical sheet (transparent composite sheet) having a particle content of 0.1% by volume was prepared.

2. Small angle X-ray scattering measurement (SAXS) for optical sheets
The sample optical sheet (Production Example 1) having a particle size of 120 nm and a particle filling amount of 33% by volume was subjected to small-angle X-ray scattering measurement under the following measurement conditions to obtain a scattering intensity spectrum. The small-angle X-ray scattering measurement was performed using synchrotron radiation X-rays generated at the radiation facility.

[Conditions for small-angle X-ray scattering measurement (synchrotron radiation X-ray)]
X-ray source: High-intensity Photoscience Research Center SPring-8 Hyogo Prefectural Beamline BL08B2
X-ray energy: 8.27 keV
X-ray wavelength: 1.5 mm (0.15 nm)
Camera length: 6000mm
Detector: Imaging plate

  The obtained two-dimensional scattering profile was made one-dimensional by circular integration, and the transmittance and air scattering correction were performed to obtain a scattering intensity spectrum (scattering profile) by X-rays. An example of the result is shown in FIG. Similarly, the small-angle X-ray scattering measurement was performed on the optical sheet having a particle content of 0.1% by volume (Production Example 2) to obtain a scattering profile. Moreover, the average particle diameter was measured as follows.

(Measuring method of average particle size)
The average particle diameter of the particles was determined by performing small-angle X-ray scattering measurement on the optical sheet (Production Example 2). After the scattering intensity profile obtained by performing small-angle X-ray scattering measurement is made one-dimensional, it is averaged by fitting the profile of the region after the wave number corresponding to the first peak of the shape factor with the theoretical scattering function of a hard sphere The particle size was obtained.

3. Reverse Monte Carlo (RMC) simulation [Structural factor extraction]
Divide the scattering profile value I (q) _33vol% of the sample optical sheet having a particle diameter of 120nm and a particle filling amount of 33vol% by the scattering profile value I (q) _0.1vol% of the particle content of 0.1vol% optical sheet. As a result, a scattering profile S (q) _33 vol% was obtained.
S (q) _33vol% = I (q) _33vol% / I (q) _0.1vol%
Further, the obtained structure S (q) _33 vol% was normalized so that the value at the time of q = 0.3 [1 / nm] becomes 1, thereby obtaining the target structure factor S (q).
S (q) = [I (q) _33vol% / I (q) _0.1vol%] / [I (q = 0.03) _33vol% / I (q = 0.03) _0.1vol%]
An example of the result is shown in FIG.

[Correction of structure factor]
Using the structure factor S (q) as an input value, the structure factor correction software MCGR (ver 3.5) reads it and performs correction calculation to obtain a corrected structure factor S (q) _fix. An example of the result is shown in FIG.

[Reverse Monte Carlo simulation]
A reverse Monte Carlo simulation was performed on a sample optical sheet having a particle diameter of 120 nm and a particle filling amount of 33% by volume under the following conditions.
[RMC simulation parameters]
Structure factor: The modified structure factor S (q) _fix was used as an input value.
Particle size: The particle size was estimated by fitting the shape factor function of a hard sphere by the least square method with respect to the scattering profile of the optical sheet having a particle content of 0.1% by volume obtained by SAXS in 2 above. The average particle size was estimated to be 120 nm.
Number density of particles: The number density of the particles in the film was calculated from the silica particle filling amount (33% by volume) and the average particle size (120 nm) of the silica particles. The number density was 3.65 × 10 ⁻⁷ nm ⁻³ . there were.
[RMC simulation software]
The software used was RMC ++ (ver.1.6.1). The initial structure used was a random box in which 10,000 particles were randomly arranged in a simulation box. The calculation was performed on a general-purpose computer (DELL Precision T7400, OS: Red Hat Enterprise Linux 5), and the simulation was completed by performing calculations for 2 hours in 8 parallels.

4). Analysis of RMC Simulation Result From the RMC simulation output file obtained in 3, the final coordinate position, structure factor S ′ (q) and radial distribution function g (r) were obtained. An example of the coordinate position is shown in FIG. 4, and the radial distribution function is shown in FIG.

  From the peak top distance of the first peak of the radial distribution function g (r), the average interparticle distance (A) of the nearest particle was obtained as 156 nm. Further, from the distance that gives the first minimum of the radial distribution function g (r), the existence range of the closest particle was estimated to be 120 to 216 nm. When the average number (B) of particles (nearest neighbor particles) existing in the above range (120 to 216 nm) was determined, it was estimated to be 14.6. The standard deviation of the number of closest particles was 1.07.

5. Evaluation The optical characteristics of the obtained optical sheet of Production Example 1 were evaluated. As evaluation items, the reflectance at 400 nm and the total light transmittance were measured. The reflectance at 400 nm and the total light transmittance were measured using an ultraviolet-visible infrared spectrophotometer V-670 manufactured by JASCO. The obtained results are shown in Table 1.

[Sample optical sheet having a particle diameter of 120 nm and a particle filling amount of 5% by volume: Production Example 3]
Preparation Example 1 except that 5 parts by weight of norbornane dimethylol diacrylate, 1 part by weight of γ-acryloxypropylmethyldimethoxysilane, and 2.1 parts by weight of isopropyl alcohol-dispersed colloidal silica were used. In the same manner, an optical sheet (transparent composite sheet) having a particle diameter of 120 nm and a particle filling amount of 5% by volume was prepared.

[Sample optical sheet having a particle diameter of 120 nm and a particle filling amount of 20% by volume: Production Example 4]
The same as in Production Example 1 except that the formulation was 5 parts by weight of norbornane dimethylol diacrylate, 1 part by weight of γ-acryloxypropylmethyldimethoxysilane, and 10 parts by weight of isopropyl alcohol-dispersed colloidal silica. An optical sheet (transparent composite sheet) having a particle diameter of 120 nm and a particle filling amount of 20% by volume was prepared.

[Sample optical sheet having a particle diameter of 120 nm and a particle filling amount of 40% by volume: Production Example 5]
Preparation Example 1 except that the formulation was 5 parts by weight of norbornane dimethylol diacrylate, 1 part by weight of γ-acryloxypropylmethyldimethoxysilane, and 26.7 parts by weight of isopropyl alcohol-dispersed colloidal silica. In the same manner, an optical sheet (transparent composite sheet) having a particle diameter of 120 nm and a particle filling amount of 40% by volume was prepared.

[Sample optical sheet having a particle diameter of 180 nm and a particle filling amount of 20% by volume: Production Example 6]
In Production Example 1, 5 parts by weight of norbornane dimethylol diacrylate, 1 part by weight of γ-acryloxypropylmethyldimethoxysilane, 2.5 parts by weight of powdered silica (SS-013; primary particle size 180 nm manufactured by Tokuyama Corporation) ) Was stirred for 2 hours at 40 ° C. under normal pressure, and 0.03 parts by weight of 1-hydroxy-cyclohexyl-phenyl-ketone (Irgacure 184 manufactured by Ciba Specialty Chemicals) was added as a photopolymerization initiator and dissolved. After that, an optical sheet (transparent composite sheet) having a particle filling amount of 20% by volume was prepared in the same manner as in Production Example 1 except that the composite composition was obtained by stirring for 1 hour. The particle diameter of the particles in the composite sheet determined by small angle X-ray scattering measurement was 180 nm.

[Sample optical sheet having a particle diameter of 180 nm and a particle filling amount of 33% by volume: Production Example 7]
The particle diameter was the same as in Comparative Example 1 except that 5 parts by weight of norbornane dimethylol diacrylate, 1 part by weight of γ-acryloxypropylmethyldimethoxysilane, and 4.9 parts by weight of powdered silica were used in Comparative Example 1. An optical sheet (transparent composite sheet) having a volume of 180 nm and a particle filling amount of 33% by volume was prepared.

  RMC simulation was carried out for Production Examples 3 to 7 in the same manner as in Production Example 1, and the average interparticle distance (A) of the closest particles and the average number (B) of the closest particles were determined. Moreover, the reflectance in 400 nm and the total light transmittance were measured with the ultraviolet visible infrared spectrophotometer. The above evaluation results are shown in Table 1.

  As shown in Table 1, the average interparticle distance (A) and / or the nearest particle number (B) can be used as indicators of good color developability (reflectance) and transparency (total light transmittance). For example, when the average interparticle distance (A) is in the range of 150 to 200 nm, a tendency that color developability (400 nm reflectivity) is more excellent is shown. Moreover, it was shown that transparency is so excellent that the number (B) of closest particles is large.

  The present disclosure is useful in the field of transparent composite sheets and their production.

Claims (5)

A transparent composite sheet comprising a transparent resin and particles, the average inter-particle distance (A) and the standard deviation of the closest particles of the particles in the transparent composite sheet, and the average number (B) of the closest particles An evaluation method using at least one of the standard deviations, wherein the average interparticle distance (A) of the closest particles and the average number (B) of the closest particles are as follows: 1) to 4) The calculated evaluation method of the transparent composite sheet.
1) obtaining a scattering intensity spectrum of the transparent composite sheet sample by small-angle X-ray scattering measurement;
2) extracting the structure factor S (q) from the scattering intensity spectrum;
3) Perform reverse Monte Carlo simulation using the structure factor S (q) to obtain particle coordinates, structure factor S ′ (q), and radial distribution function g (r) as outputs;
4) Obtaining the value of the interparticle distance that gives the maximum value of the first peak of the radial distribution function g (r) as the average interparticle distance (A) of the nearest particle, and / or the average particle of the particle A value obtained by calculating from the particle coordinates the number of particles existing in the range from the diameter to the first minimum of the radial distribution function g (r) is obtained as the average number (B) of the closest particles. A transparent composite sheet product,
A transparent composite sheet comprising a transparent resin and particles, and
Information of at least one of the average interparticle distance (A) of the closest particles of the particles in the transparent composite sheet and the standard deviation thereof, and the average number (B) of the closest particles and the standard deviation thereof,
The transparent composite sheet product in which the average interparticle distance (A) of the closest particles and the average number (B) of the closest particles are calculated by the following 1) to 4).
1) obtaining a scattering intensity spectrum of the transparent composite sheet sample by small-angle X-ray scattering measurement;
2) extracting the structure factor S (q) from the scattering intensity spectrum;
3) Reverse Monte Carlo simulation is performed using the structure factor S (q), and particle coordinates, structure factor S ′ (q), and radial distribution function g (r) are obtained as outputs;
4) Obtaining the value of the interparticle distance that gives the maximum value of the first peak of the radial distribution function g (r) as the average interparticle distance (A) of the nearest particle, and / or the average particle of the particle A value obtained by calculating from the particle coordinates the number of particles existing in the range from the diameter to the first minimum of the radial distribution function g (r) is obtained as the average number (B) of the closest particles. A transparent composite sheet containing a transparent resin and particles,
The average primary particle size of the particles is 50 to 200 nm,
The transparent composite sheet whose average interparticle distance (A) of the nearest particle | grains obtained by the evaluation method of Claim 1 is 100-300 nm. A transparent composite sheet containing a transparent resin and particles,
The average primary particle size of the particles is 50 to 200 nm,
The transparent composite sheet whose average number (B) of the nearest particle | grains obtained by the evaluation method of Claim 1 is 6-20. The substrate for electronic components manufactured using the transparent composite sheet product of Claim 2, or the transparent composite sheet of Claim 3 or 4.

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