JP2009150979A - Blue haze evaluation method and blue haze evaluation device - Google Patents

Abstract

Provided is a method capable of directly evaluating a blue haze that changes to bluish white when sunlight or the like hits a near-infrared shielding material fine particle dispersion.
A blank transmitted light intensity measurement step for obtaining spectral data of reflected light by allowing light from a light source 1 to enter a spherical space with a standard reflector attached to an integrating sphere 4 and no measurement sample attached thereto, and an integrating sphere With the light trap part 6 attached and the measurement sample 2 attached, the diffused transmitted light intensity measuring step for obtaining the spectral data of the scattered light by causing the light from the light source to enter the spherical space, and the diffused transmitted light based on each spectral data Diffuse transmittance calculation process to obtain the diffuse transmittance for each wavelength by calculating the ratio of intensity and blank transmitted light intensity for each wavelength, and evaluate the blue haze of the measurement sample from the diffuse transmittance between wavelengths 360nm and 500nm An evaluation step is provided.
[Selection] Figure 2

Description

  The present invention relates to a method for evaluating a near-infrared shielding material fine particle dispersion that is transparent in the visible light region and absorbs in the near-infrared region, and in particular, when the dispersion is irradiated with sunlight or the like, the color changes to blue-white. The present invention relates to a blue haze evaluation method and a blue haze evaluation apparatus that can evaluate in advance whether or not a phenomenon (hereinafter referred to as blue haze) is likely to occur.

  As a shading member used for windows of buildings and transportation equipment, inorganic pigments such as carbon black and titanium black that absorb from the visible light region to the near infrared region, and black pigments such as organic pigments such as aniline black There are known light-shielding films containing light and half-mirror type light-shielding members in which a metal such as aluminum is vapor-deposited. Although these materials have low saturation and a black tone, they are frequently used because a black tone is often preferred in terms of design and practicality.

  Moreover, as a light-shielding member used for windows of buildings and transportation equipment, in addition to the above-described black pigments and metal deposition films, hexaboride having the property of selectively absorbing near infrared rays of about 1000 nm A fine particle dispersion film (see, for example, Patent Documents 1 and 2), a tungsten oxide fine particle having a characteristic of selectively absorbing near-infrared rays of about 1000 nm and a characteristic of transmitting a visible light region of 380 nm to 780 nm or / Also, a near-infrared shielding material fine particle dispersion containing composite tungsten oxide fine particles (see Patent Document 3) has been proposed.

  The near-infrared shielding material fine particle dispersion film and the near-infrared shielding material fine particle dispersion having the property of transmitting the visible light region and selectively absorbing the near infrared light have the property of transmitting the visible light region. Therefore, it is necessary to evaluate haze. As an evaluation method, a method of measuring the transparency of a sample and expressing turbidity (cloudiness) is used. About this turbidity (cloudiness), it is calculated | required from the ratio with respect to the total light transmitted light of the diffuse transmission light in evaluation samples, such as a near-infrared shielding material fine particle dispersion, Specifically, the said turbidity ( The haze is measured (see, for example, Patent Document 4).

  By the way, the near-infrared shielding material fine particle dispersion film and the near-infrared shielding material fine particle dispersion cause a phenomenon (blue haze) that turns blue-white when the dispersion film or the dispersion is irradiated with sunlight or the like. I understand.

  However, the cause of the occurrence of blue haze has not been grasped, and there is no method for directly evaluating how much blue haze is generated, which has become a problem. For example, for a dispersion having a low haze and a high transparency, it was impossible to distinguish between a dispersion that turned pale blue when irradiated with sunlight or the like and a dispersion that did not turn pale blue.

When a near-infrared shielding material fine particle dispersion film or a near-infrared shielding material fine particle dispersion (hereinafter, the dispersion film is also included in the category of dispersion) that generates blue haze is used for a windshield of a car, It is feared that it will cause a safety problem because it will turn pale and become poorly visible. In addition, there is a concern that window glass for building materials may lose aesthetics due to the occurrence of blue haze, and in plasma display panels and the like, the contrast may be greatly reduced due to the occurrence of blue haze, which may impair vividness and visibility. The
JP 2000-96034 A (Claims) JP 2000-72484 A (Claims) JP 2006-10759 A (Claims) JP 2000-211063 A (paragraph 0015)

  The present invention has been made paying attention to such problems, and the problem is that the blue haze that turns blue-white when sunlight or a spotlight hits the near-infrared shielding material fine particle dispersion is applied. It is to provide a method capable of direct evaluation and a blue haze evaluation apparatus.

  In order to solve the above-mentioned problems, the present inventor investigated the phenomenon of blue haze that turns blue-white when sunlight or spotlight hits a near-infrared shielding material for building materials and the like from the cause of the occurrence. .

  Normal haze is caused by the fact that incident light is scattered by a filler or the like in the medium. When the particle size of the filler is larger than 200 nm, the visible light region of 400 nm to 780 nm is caused by geometrical scattering or Mie scattering. It is known to scatter light and become a frosted glass, and this haze can be measured by a conventional haze meter.

  On the other hand, when the particle size is 200 nm or less, it is known that geometric scattering or Mie scattering is reduced, and most of the scattering follows Rayleigh scattering whose scattering coefficient is defined by the following formula (1).

S = [16π ⁵ r ⁶ / 3λ ⁴ ] · [(m ² −1) / (m ² +2)] ² · [m] (1)
[In the above formula (1), S is the scattering coefficient, λ is the wavelength, r is the particle diameter, m = n ₁ / n ₀ , n ₀ is the refractive index of the substrate, and n ₁ is the refractive index of the dispersed material. Is]
The Rayleigh scattering is light scattering by particles having a size smaller than the wavelength of light, and occurs in a transparent liquid or solid, but a typical phenomenon is scattering in a gas. Incidentally, the phenomenon that sunlight is scattered in the atmosphere and the sky looks blue is known to be due to Rayleigh scattering.

  Since the Rayleigh scattering is inversely proportional to the fourth power of the wavelength from the equation (1), it is estimated that a large amount of blue light having a short wavelength is scattered and discolored to a blue-white color even in the solid. Therefore, the present inventor presumed that this was the cause of the occurrence of blue haze. In this Rayleigh scattering region, since the scattered light is proportional to the sixth power of the particle diameter from Equation (1), Rayleigh scattering is reduced and transparency is improved as the particle diameter is reduced.

  However, since the blue haze cannot be measured directly with a conventional haze meter (see Patent Document 4), the present inventor has obtained a plurality of samples (near-infrared shielding material fine particle dispersion) having a filler particle size of 200 nm or less. Blue haze can be directly evaluated by paying attention to linear incident light and scattered light as components of transmitted light when light is applied to these samples, and obtaining diffuse transmittance for each wavelength. And the present invention has been completed.

That is, the invention according to claim 1
The inner surface of the spherical body has diffuse reflectivity, and the first opening to which the measurement sample is attached, the second opening to which the standard reflector or the light trap part is attached, and the third opening to which the light receiver is attached are the spherical body. In the method of evaluating the blue haze of the near-infrared shielding material fine particle dispersion using the integrating sphere on the outer surface,
A standard reflector is attached to the second opening of the integrating sphere, and linear light from an external light source is incident into the spherical space through the first opening without attaching a measurement sample to the first opening. A blank transmitted light intensity measuring step of receiving the reflected light reflected by the reflecting plate with the light receiver and separating the reflected light with a spectroscope to obtain spectral data of the reflected light;
A light trap component is attached to the second opening of the integrating sphere, and linear light from an external light source is incident on the spherical space through the measurement sample and the first opening with the measurement sample attached to the first opening. A diffused transmitted light intensity measurement step of receiving scattered light other than the light trapped by the light trap component with the light receiver, and obtaining the spectral data of the scattered light by separating the light with the spectroscope,
Based on the stored spectral data of the above-mentioned blank transmitted light intensity and diffuse transmitted light intensity, the diffuse transmission to obtain the diffuse transmittance for each wavelength by calculating the ratio of the diffuse transmitted light intensity and the blank transmitted light intensity for each wavelength. Rate calculation process;
An evaluation process for evaluating the blue haze of the near-infrared shielding material fine particle dispersion, which is a measurement sample, from the diffuse transmittance for each wavelength,
It is characterized by comprising,
The invention according to claim 2
In the blue haze evaluation method according to the invention of claim 1,
The size of the blue haze is evaluated from the maximum value of the diffuse transmittance between wavelengths of 360 nm and 500 nm.

Next, the invention according to claim 3 is
In the blue haze evaluation apparatus used for the evaluation method according to claim 1 or 2,
The inner surface of the spherical body has diffuse reflectivity, and the first opening to which the measurement sample is attached, the second opening to which the standard reflector or the light trap part is attached, and the third opening to which the light receiver is attached are the spherical body. An integrating sphere on the outer surface;
A light source that emits linear light that enters the spherical space through the first opening;
A spectroscope that is attached to the light receiver and separates the reflected or scattered light received;
Data storage means connected to the spectroscope and storing spectral data of the reflected or scattered light that has been dispersed;
Calculation means for obtaining a diffuse transmittance for each wavelength by calculating a ratio for each wavelength of the diffuse transmitted light intensity and the blank transmitted light intensity from each stored spectral data of the blank transmitted light intensity and the diffuse transmitted light intensity,
It is characterized by comprising.

  In the blue haze evaluation method according to the present invention, the standard reflector is attached to the second opening of the integrating sphere, and the linear light from the external light source is applied to the first opening without attaching the measurement sample to the first opening. And a blank transmitted light intensity measuring step for receiving the reflected light reflected by the standard reflector and receiving the reflected light by the standard reflector, and separating the reflected light by the spectrometer to obtain spectral data of the reflected light. The light trap component is attached to the second opening of the integrating sphere, and the linear light from the external light source is incident on the spherical space through the measurement sample and the first opening with the measurement sample attached to the first opening. And a diffused transmitted light intensity measuring step for receiving scattered light other than the light trapped by the light trap component with the light receiver and separating the light with the spectroscope to obtain spectral data of the scattered light, and stored. Above A diffuse transmittance calculating step for obtaining a diffuse transmittance for each wavelength by calculating a ratio for each wavelength of the diffuse transmitted light intensity and the blank transmitted light intensity based on each spectral data of the ink transmitted light intensity and the diffuse transmitted light intensity; And an evaluation step of evaluating the blue haze of the near-infrared shielding material fine particle dispersion, which is a measurement sample, from the diffuse transmittance for each wavelength.

  Therefore, since the blue haze of the near-infrared shielding material fine particle dispersion can be directly evaluated from the diffuse transmittance for each wavelength, the near-infrared shielding material fine particle dispersion applied to the windshield of a car, the window for building materials, etc. The near-infrared shielding material fine particle dispersion applied to glass or the like or the near-infrared shielding material fine particle dispersion applied to a display device such as a plasma display panel can be predicted in advance for the occurrence or size of blue haze. It has an effect that can be done.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.

  1 and 2 are explanatory views showing the principle of the blue haze evaluation apparatus of the present invention.

  First, as shown in FIGS. 1 and 2, the blue haze evaluation apparatus according to the present invention has a first opening (not shown) in which the inner surface of the spherical body has diffuse reflectivity and the measurement sample 2 is attached, standard reflection. An integrating sphere 4 having a second opening (not shown) to which the plate 5 or the light trap component 6 is attached, a third opening (not shown) to which the light receiver 3 is attached on the outer surface of the spherical body, and the first opening A light source 1 that emits linear light that is incident on the spherical space through the unit, a spectroscope (not shown) that is attached to the light receiver 3 and that separates the received reflected or scattered light, and the spectroscope 3 and a data storage means (not shown) for storing spectral data of reflected or scattered light that has been spectrally dispersed, and diffused transmitted light from the stored spectral data of the blank transmitted light and diffused transmitted light. Strength and blank transparency Is characterized by comprising a calculating means for obtaining a diffuse transmittance of each wavelength by calculating the ratio of each wavelength of the light intensities respectively (not shown).

  Here, the integrating sphere 4 having the first, second and third openings (not shown) on the outer surface of the spherical body is diffused by applying barium sulfate or Spectralon (registered trademark) or the like on the inner surface of the spherical body. It has reflectivity, and the incident angle to the standard reflecting plate 5 may be 10 ° on both the standard side and the reference side. As the light receiver 3, for example, a photomultiplier tube (ultraviolet / visible region) or a cooled lead sulfide (near infrared region) can be used. Further, a spectroscope (not shown) attached to the light receiver 3 needs to have a wavelength measurement range in the ultraviolet / visible range and photometric accuracy (± 0.002 Abs).

  Next, as the light source 1 that emits linear light that enters the spherical space, for example, a deuterium lamp is applied in the ultraviolet region, and a 50 W halogen lamp is applied in the visible / near infrared region.

  The standard reflector 5 can be, for example, a white plate of SPECTRALON (registered trademark), and the light trap component 6 has a function of trapping incident linear light without reflecting it. For example, a dark box that absorbs incident linear light almost completely is used.

  And using this blue haze evaluation apparatus, in order to evaluate the blue haze of the near-infrared shielding material fine particle dispersion as a measurement sample, a blank transmitted light intensity measuring step, a diffuse transmitted light intensity measuring step, a diffuse transmission Each process of a rate calculation process and an evaluation process is required.

  First, in the blank transmitted light intensity measuring step, the standard reflector 5 is attached to the second opening of the integrating sphere 4 as shown in FIG. 1, and the external light source 1 is attached without the measurement sample attached to the first opening. Is incident on the spherical space through the first opening, the reflected light reflected by the standard reflector 5 is received by the light receiver 3, and a spectroscope (not shown) attached to the light receiver 3 is shown. To obtain spectral data of the reflected light.

  Next, in the diffuse transmitted light intensity measurement step, an external light source is attached with the light trap component 6 attached to the second opening of the integrating sphere 4 and the measurement sample 2 attached to the first opening as shown in FIG. The linear light from 1 enters the spherical space through the measurement sample 2 and the first opening, and scattered light other than the light trapped by the light trap component 6 is received by the light receiver 3, and the light receiver Spectral data (scattered light) is obtained by spectroscopic analysis using a spectroscope (not shown) attached to 3.

  Then, in the diffuse transmittance calculation step, based on the spectral data of the blank transmitted light intensity and the diffuse transmitted light intensity stored by the data storage means (not shown), the diffuse transmitted light intensity is calculated by the calculating means (not shown). And the ratio of the transmitted light intensity for each wavelength to obtain the diffuse transmittance for each wavelength, and from the obtained diffuse transmittance for each wavelength, the blue haze of the near-infrared shielding material fine particle dispersion that is the measurement sample Can be evaluated (evaluation process).

  In addition, in the measurement using the conventional haze meter (refer patent document 4), the diffuse transmittance for every wavelength cannot be calculated | required, but the ratio with respect to the total light transmitted light of the diffuse transmitted light in an evaluation sample is calculated | required as mentioned above. Therefore, it was difficult to evaluate the blue haze of the near-infrared shielding material fine particle dispersion.

  Here, in the blue haze evaluation apparatus according to the present invention, a light adjustment optical system may be provided between the light source 1 and the measurement sample 2. In this optical system, for example, parallel light is adjusted by combining a plurality of lenses, and the amount of light is adjusted by a diaphragm. In some cases, a specific wavelength may be cut by a filter. Further, as the measurement sample 2, a near-infrared shielding material fine particle dispersion (a paint in which near-infrared shielding material fine particles are dispersed in a solvent) may be accommodated in a cell as it is, or may be arranged as described above. You may arrange | position the near-infrared shielding material fine particle dispersion (dispersion film | membrane of the near-infrared shielding material microparticles | fine-particles formed into a film on the transparent base material) obtained by thin-film coating a coating material on a transparent base material.

  Then, based on the diffuse transmittance for each wavelength obtained by this evaluation method, for example, the size of the blue haze can be estimated from the maximum value of the diffuse transmittance between the wavelengths of 360 nm and 500 nm.

Examples of the present invention will be specifically described below.
[Example 1-3]
13 parts by weight of LaB ₆ powder having a particle size of 1 to 3 μm and 87 parts by weight of 2-propanol were stirred and mixed to prepare 3 kg of slurry.

Next, this slurry was put into a medium stirring mill together with the beads, and the slurry was circulated to carry out pulverization and dispersion treatment. Medium stirring mill used was a horizontal cylindrical annular type [Ashizawa Co., Ltd.], the material of the vessel inner wall and a rotor (rotary stirring portion) was set to ZrO _2. Further, beads made of YSZ (Yttria-Stabilized Zirconia) having a diameter of 0.3 mm were used as the beads. The rotation speed of the rotor is 12 m / sec, the slurry flow rate is 1 kg / min, the pulverization time is changed to 10 hours (Example 1), 20 hours (Example 2), and 30 hours (Example 3). Dispersions having different particle sizes of LaB ₆ powder were prepared.

The average dispersed particle size of LaB ₆ powder in Example 1 was 110 nm, the average dispersed particle size of LaB ₆ powder in Example 2 was 85 nm, and the average dispersed particle size of LaB ₆ powder in Example 3 was 65 nm. Moreover, these average dispersed particle diameters were taken as the average value of values measured by a measuring apparatus using a dynamic light scattering method [ELS-800 manufactured by Otsuka Electronics Co., Ltd.].

  The obtained dispersion liquid of Example 1-3 was mixed with an ultraviolet curable resin, formed into a film on a glass substrate with a bar coater, and after the solvent was evaporated, it was cured by irradiation with ultraviolet rays.

Here, since the visible light transmittance changes when the particle size of the LaB ₆ powder is different, the concentration is adjusted according to the amount of the ultraviolet curable resin added to the dispersion, or the film thickness at the time of film formation is almost adjusted. The haze was measured with a thin film having the same visible light transmittance. The results are shown in Table 1.

  The visible light transmittance was measured according to JIS R3106. The haze value was measured according to JIS K7105. Moreover, the diffusion transmission profile of the obtained film | membrane was measured by the method shown in FIG. 1 and FIG. 2 which is the evaluation method based on this invention. The results are shown in Table 1 and FIG.

Furthermore, the artificial solar lamp [XC-100 made by Celic Co., Ltd.] was irradiated on the obtained film, and the blue haze was visually confirmed. The result is shown in FIG.
[Example 4]
An organic infrared shielding material composed of a phthalocyanine dye and a two-component cross-linking acrylic adhesive material are mixed at a weight ratio of 1:10, formed on a glass substrate, evaporated and then aged. Thus, an infrared shielding film sample having a thickness of 100 μm was produced.

  And the obtained infrared shielding film sample which concerns on Example 4 was evaluated by the method similar to Example 1-3. The results are shown in Table 1 and FIGS. 3 and 4.

「評 価」
（１）表１の「ヘイズ（％）」欄から実施例１に係る試料と実施例４に係る試料は共にヘイズ値が０．８％になっている。

"Evaluation"
(1) From the “Haze (%)” column in Table 1, both the sample according to Example 1 and the sample according to Example 4 have a haze value of 0.8%.

  However, from the photograph of the blue haze shown in FIG. 4, it is confirmed that the sample according to Example 1 has a very strong blue haze, whereas the sample according to Example 4 has no blue haze. it can. The reason for this difference is that in the sample according to Example 4, an organic infrared shielding material made of a phthalocyanine dye (this material does not generate blue haze) is applied.

  On the other hand, from the “diffuse transmittance peak value” column in the wavelength range of 360 nm to 500 nm in Table 1, the peak (maximum) value of the sample according to Example 1 is 2.6%. The peak (maximum) value is larger than 0.7%.

Therefore, from the numerical value in the “diffuse transmittance peak value” column between wavelengths of 360 nm and 500 nm (or from the diffuse transmission profile shown in FIG. 3), the presence or absence and the magnitude of blue haze in each sample are evaluated in advance. It turns out that it is possible to do.
(2) Next, in Example 1-3, although the LaB ₆ powder is applied, the peak (maximum) value in the “diffuse transmittance peak value” column between the wavelengths of 360 nm and 500 nm is It is confirmed that there is a big difference.

  That is, while the sample according to Example 1 has a peak (maximum) value of 2.6%, the sample according to Example 2 has 1.0%, and the sample according to Example 3 has 0.7%. ing.

The reason why such a difference occurs is that, in Examples 2 and 3 as compared with Example 1, the pulverization progressed and the particle size became smaller, and thus the blue haze was gradually improved. That is, the blue haze of Example 3 is only slightly recognized and is at the same level as Example 4 where the organic material was applied. The numerical value in the column of “diffuse transmittance peak value” between wavelengths 360 nm and 500 nm is 0.7% in both Example 3 and Example 4, and “diffuse transmittance peak value” between wavelengths 360 nm and 500 nm. It can be seen from the numerical values in the column (or from the diffuse transmission profile shown in FIG. 3) that the size of the blue haze can be evaluated in advance.
(3) As described above, it was confirmed that the evaluation method according to the present invention enables the evaluation of the blue haze, which was difficult to judge only by the conventional haze value measurement.

  According to the blue haze evaluation method according to the present invention, the blue haze of the near-infrared shielding material fine particle dispersion can be directly evaluated. Therefore, the method is applied to a windshield of a car, a window glass for building materials, a plasma display panel, or the like. The near-infrared shielding material fine particle dispersion has an industrial applicability in which the presence or absence of blue haze and its size can be predicted in advance.

Explanatory drawing which shows the method of measuring blank transmitted light intensity using the blue haze evaluation apparatus which concerns on this invention. Explanatory drawing which shows the method of measuring diffuse transmission light intensity using the blue haze evaluation apparatus which concerns on this invention. The graph of the diffuse transmittance profile which shows the relationship between the wavelength calculated | required by the blue haze evaluation method which concerns on this invention, and diffuse transmittance. The photograph figure which shows the blue haze phenomenon of the sample in Example 1-4.

Explanation of symbols

1 Light Source 2 Measurement Sample 3 Light Receiver 4 Integrating Sphere 5 Standard Reflector 6 Light Trap Parts

Claims (3)

The inner surface of the spherical body has diffuse reflectivity, and the first opening to which the measurement sample is attached, the second opening to which the standard reflector or the light trap part is attached, and the third opening to which the light receiver is attached are the spherical body. In the method of evaluating the blue haze of the near-infrared shielding material fine particle dispersion using the integrating sphere on the outer surface,
A standard reflector is attached to the second opening of the integrating sphere, and linear light from an external light source is incident into the spherical space through the first opening without attaching a measurement sample to the first opening. A blank transmitted light intensity measuring step of receiving the reflected light reflected by the reflecting plate with the light receiver and separating the reflected light with a spectroscope to obtain spectral data of the reflected light;
A light trap component is attached to the second opening of the integrating sphere, and linear light from an external light source is incident on the spherical space through the measurement sample and the first opening with the measurement sample attached to the first opening. A diffused transmitted light intensity measurement step of receiving scattered light other than the light trapped by the light trap component with the light receiver, and obtaining the spectral data of the scattered light by separating the light with the spectroscope,
Based on the stored spectral data of the above-mentioned blank transmitted light intensity and diffuse transmitted light intensity, the diffuse transmission to obtain the diffuse transmittance for each wavelength by calculating the ratio of the diffuse transmitted light intensity and the blank transmitted light intensity for each wavelength. Rate calculation process;
An evaluation process for evaluating the blue haze of the near-infrared shielding material fine particle dispersion, which is a measurement sample, from the diffuse transmittance for each wavelength,
A method for evaluating blue haze, comprising:   2. The blue haze evaluation method according to claim 1, wherein the size of the blue haze is evaluated from a maximum value of the diffuse transmittance between wavelengths of 360 nm and 500 nm. In the blue haze evaluation apparatus used for the evaluation method according to claim 1 or 2,
The inner surface of the spherical body has diffuse reflectivity, and the first opening to which the measurement sample is attached, the second opening to which the standard reflector or the light trap part is attached, and the third opening to which the light receiver is attached are the spherical body. An integrating sphere on the outer surface;
A light source that emits linear light that enters the spherical space through the first opening;
A spectroscope that is attached to the light receiver and separates the reflected or scattered light received;
Data storage means connected to the spectroscope and storing spectral data of the reflected or scattered light that has been dispersed;
Calculation means for obtaining a diffuse transmittance for each wavelength by calculating a ratio for each wavelength of the diffuse transmitted light intensity and the blank transmitted light intensity from each stored spectral data of the blank transmitted light intensity and the diffuse transmitted light intensity,
A blue haze evaluation apparatus comprising:

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