JP2013166350A - Blind sheet - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a blind sheet comprising a matte layer on a light transmissive substrate and capable of suppressing angular dependence of specular glossiness.SOLUTION: A blind sheet 1 includes a matte layer 3 on a light transmissive substrate 2. The matte layer 3 includes a binder resin 31 and a pigment 32. A particle diameter variation coefficient of the pigment 32 is ≥20%, an average particle diameter of the pigment 32 is 4 to 12 μm, and a thickness of the matte layer 3 is 4 to 8.5 μm.

Description

  The present invention relates to a blindfold sheet used for a window glass or a partition.

  2. Description of the Related Art In recent years, a blindfold sheet has been bonded in order to blind a part of a large area transparent window glass of a commercial facility. This blindfold sheet (see, for example, Patent Document 1) has fine irregularities on the surface of the light-transmitting base material, and transmitted light is scattered, so that visibility from the outside is hindered.

  Generally, the blindfold sheet has fine irregularities on the surface of the light-transmitting substrate. There are several methods for applying the unevenness. Typical methods include sandblasting, which applies sand to the surface of the light-transmitting substrate to roughen the surface of the light-transmitting substrate, and coating and drying the surface of the light-transmitting substrate. There is a coating method in which a mat layer is provided. In recent years, the latter coating method, which is excellent in mass productivity, is often used.

  The mat layer by this coating method is mainly a mixture of a resin and a pigment serving as a binder, and the degree of blinding and specular gloss largely depend on the selection of the type and amount of resin and pigment.

  However, with these methods, even if the degree of blinding is good, the specular gloss changes depending on the angle at which the surface of the mat layer is viewed, resulting in a defective appearance, or reflection caused by reflection of external light entering from all angles. There were concerns about pollution.

JP 2009-530147 A

  Therefore, an object of the present invention is to provide a blindfold sheet in which the angle dependency of the specular gloss can be suppressed in the mat layer on the surface of the light transmissive substrate.

  As a result of diligent research to solve the above problems, the present inventors have selected a pigment having a coefficient of variation in particle diameter of 20% or more as the pigment for the matte layer. And it has been found that by containing a pigment having a particle diameter variation coefficient of 20% or more, a blindfold sheet can be obtained in which the angle dependency of the specular gloss is suppressed in the mat layer on the surface of the light-transmitting substrate. It was.

  That is, the blindfold sheet of the present invention has a mat layer on a light-transmitting substrate, the mat layer includes a binder resin and a pigment, and the variation coefficient of the particle diameter of the pigment is 20% or more. It is characterized by being.

  The blindfold sheet of the present invention is characterized in that the mat layer has a thickness of 4 to 8.5 μm.

  The specular gloss referred to in the present invention was measured using a gloss meter based on JIS-Z8741: 1997 (unit:%). Specular gloss is a parameter that indicates the degree of reflection of light incident on the surface of the matte layer. The smaller this value, the lower the glossiness, and the lower the glossiness, the more the matte effect is judged. The The 45-degree specular gloss (G45) is defined as how much 100 light incident at an angle inclined by 45 degrees from the vertical direction of the mat layer surface is reflected on the light receiving section inclined by 45 degrees on the reflection side. This is a parameter indicating whether (incident on the light receiving portion). The 60 degree specular gloss (G60) and 75 degree specular gloss (G75) are based on the same idea.

  Moreover, the average particle diameter as used in the field of this invention is the value measured by the Coulter counter method.

  The variation coefficient of the particle diameter of the pigment referred to in the present invention represents how much the variation in the particle diameter of the pigment is relative to the average particle diameter, and the value is an average of the standard deviation of the particle diameter. It is a percentage value obtained by dividing by the particle diameter. The smaller the particle size variation coefficient is, the smaller the particle size distribution is, and the particle size is uniform and the particle size is uniform. Conversely, the larger the particle size variation coefficient is, the wider the particle size distribution is. It means that the particle size is not uniform and uniform.

  When the blindfold sheet of the present invention is pasted on a window glass, visibility from the outside can be sufficiently prevented, and an excellent blindfold effect can be obtained. In addition, the angle dependency of the specular gloss can be suppressed in the mat layer on the surface of the light-transmitting substrate.

Sectional view showing an example of a blindfold sheet Sectional drawing which shows one Embodiment of the sheet | seat for blindfolds of this invention

  The blindfold sheet of the present invention has a mat layer on a light-transmitting substrate, the mat layer includes a binder resin and a pigment, and the coefficient of variation in the particle diameter of the pigment is 20% or more. It is characterized by. Hereinafter, embodiments of each component will be described.

  The blindfold sheet of the present invention has a configuration having a mat layer on a light-transmitting substrate.

  As the light transmissive substrate, various light transmissive plastic films and light transmissive glass can be used. For example, a plastic film made of polyethylene terephthalate, polyethylene naphthalate, polycarbonate, polypropylene, polyethylene, polyvinyl chloride, polystyrene, (meth) acrylic ester resin, fluorine resin, or the like can be used. The thickness of these light-transmitting substrates is not particularly limited, but is preferably about 6 μm to 2 mm, and more preferably about 12 μm to 200 μm. Further, these preferably have a total light transmittance of 50% or more, more preferably 70% or more, and still more preferably 90% or more. It may contain an ultraviolet absorber or a light stabilizer.

  The mat layer includes a binder resin and a pigment.

  Examples of the binder resin contained in the mat layer include poly (meth) acrylic resin, polyester resin, polyvinyl acetate resin, polyvinyl chloride, polyvinyl butyral resin, cellulose resin, polystyrene / polybutadiene resin, polyurethane resin, and alkyd. Resin, acrylic resin, unsaturated polyester resin, epoxy ester resin, epoxy resin, acrylic polyol resin, polyester polyol resin, polyisocyanate, epoxy acrylate resin, urethane acrylate resin, polyester acrylate resin, polyether acrylate resin, phenol Thermoplastic resins or thermosetting resins such as resin, melamine resin, urea resin, diallyl phthalate resin and the like. As the binder resin, one kind or a mixture of two or more kinds thereof are used, and can be selected in consideration of adhesiveness to a film substrate to be used, light transmittance, dispersibility of a pigment to be used, and the like.

  As pigments contained in the mat layer, silica, alumina, talc, clay, calcium carbonate, magnesium carbonate, barium sulfate, aluminum hydroxide, titanium dioxide, zirconium oxide, and other inorganic particles, acrylic resin particles, silicone resin particles, Examples of the resin particles include nylon resin particles, styrene resin particles, polyethylene resin particles, benzoguanamine resin particles, and urethane resin particles. In the present invention, inorganic particles may be used, but if spherical resin particles are used, the angular dependency of the specular gloss can be further suppressed, and thus spherical resin particles are preferably used.

  In the present invention, by including a pigment having a coefficient of variation of particle diameter of 20% or more as the pigment of the matte layer, the angle dependency of the specular gloss can be suppressed. The reason for this is not clear, but can be considered as follows.

  First, looking at the amount of incident light reflected at various incident angles, the amount of reflected light at an angle close to the vertical direction with respect to the surface of the mat layer can be suppressed by simply reducing the gloss if the surface is rough. However, in order to suppress the amount of reflection of light incident from an angle close to the horizontal direction as in G45, G60, and G75, there is a case where low gloss is not obtained simply by roughening. As a result of intensive studies, it is effective to uniformly rough the surface of the mat layer with small irregularities in order to suppress the reflection of incident light from a direction close to vertical, but the reflection of incident light from a direction close to horizontal is effective. In order to suppress this, it has been found that large and deep irregularities need to be present, not only with small irregularities.

  Hereinafter, description will be made with reference to the drawings. First, pigments having a coefficient of variation in particle diameter of 20% or less have a small value, so the pigment particle diameters are relatively uniform. And in the mat layer containing the pigment whose particle diameter variation coefficient is 20% or less, since the particle diameter of the pigment is uniform, the surface of the mat layer is likely to have small and shallow irregularities (FIG. 1). On the other hand, pigments having a coefficient of variation in particle diameter of 20% or more have a large value, so the particle diameters of the pigments are not uniform. And in the mat layer containing the pigment whose particle diameter variation coefficient is 20% or more, since the particle diameter of the pigment is not uniform, both large and deep irregularities and small irregularities coexist on the surface of the mat layer. Things are easy to make (Figure 2).

  As shown in FIG. 2, in a mat layer containing a pigment having a particle diameter variation coefficient of 20% or more, light incident from an angle close to the horizontal direction is blocked by a large convex portion and hardly reaches the opposite direction. The blocked light is considered to be absorbed by small unevenness or attenuated by diffuse reflection. Therefore, it is considered that the angle dependency of the specular glossiness can be suppressed by the presence of pigments having uneven particle diameters and large and deep irregularities.

  As described above, in the present invention, by including a pigment having a coefficient of variation in particle diameter of 20% or more as the pigment of the mat layer, large and deep irregularities and small irregularities exist on the surface of the mat layer, and the specular gloss The angle dependency of the degree can be suppressed. The variation coefficient of the particle diameter of the pigment is more preferably 25% or more, and further preferably 30% or more.

  Further, the average particle diameter of the pigment varies depending on the thickness of the mat layer, and thus cannot be generally described, but is preferably 4 to 12 μm. When the average particle diameter of the pigment is 4 μm or more, large and deep irregularities are likely to occur on the surface of the mat layer, and the angle dependency of the specular gloss is easily suppressed. Moreover, if the average particle diameter of the pigment is 12 μm or less, it is easy to prevent the pigment from falling off the coating film. The average particle diameter of the pigment is more preferably 4.5 to 11 μm, and further preferably 5 to 10 μm.

  Furthermore, the average particle diameter of the pigment is preferably 0.5 to 3 times the thickness of the mat layer. When the average particle diameter of the pigment is 0.5 times or more with respect to the thickness of the mat layer, large and deep irregularities are likely to occur on the surface of the mat layer, and the angle dependency of the specular gloss is easily suppressed. Moreover, if the average particle diameter of the pigment is 3 times or less with respect to the thickness of the mat layer, it is easy to prevent the pigment from falling off the coating film. In addition, the average particle diameter of the pigment is more preferably 0.6 to 2.5 times, and further preferably 0.7 to 2 times the thickness of the mat layer.

  Further, the pigment content is different from the required concealability and glossiness, and cannot be generally stated, but it is preferably 20 to 80 parts by weight with respect to 100 parts by weight of the binder resin. By making the pigment content 20 parts by weight or more with respect to 100 parts by weight of the binder resin, the blinding effect can be made sufficiently easy, and by making it 80 parts by weight or less, the adhesion to the substrate can be maintained. it can. The pigment content is more preferably 30 to 70 parts by weight and even more preferably 40 to 60 parts by weight with respect to 100 parts by weight of the binder resin.

  Further, in the present invention, the thickness of the mat layer is preferably 4 to 8.5 μm although it varies depending on the particle diameter of the pigment. By setting the thickness of the mat layer to 4 μm or more, large and deep irregularities are easily formed on the surface of the mat layer, and the angle dependency of the specular gloss is easily suppressed. Further, when the thickness of the mat layer is 8 μm or less, the particles are less likely to be embedded in the mat layer, so that large and deep irregularities are easily formed on the surface of the mat layer. In addition, the thickness of the mat layer is more preferably 4.5 to 8 μm, and further preferably 5 to 7.5 μm.

  As an index of the above-mentioned blindfold effect of the blindfold sheet, it is preferable that the haze of JIS K7136: 2000 is 60% or more.

  It is preferable to provide an adhesive layer for adhering to the adherend on the surface of the plastic film opposite to the mat layer. As the adhesive layer, a pressure-sensitive adhesive such as an acrylic pressure-sensitive adhesive or a rubber-based pressure-sensitive adhesive, an adhesive such as a hot-melt adhesive, or a thermocompression-bondable thermoplastic resin film can be used. . When using a pressure-sensitive adhesive, it is preferable to attach a separator on the adhesive layer so as not to impair the handleability of the blindfold sheet. As the separator, those obtained by subjecting various synthetic resin films to a release treatment can be used.

  Note that an ultraviolet absorber or an ultraviolet shielding agent may be added to the mat layer and the adhesive layer. By doing so, the ultraviolet-ray deterioration of the thing inside the to-be-adhered body which bonded the blindfold sheet | seat can be prevented.

  You may add additives, such as a hardening | curing agent and a leveling agent, in the mat | matte layer and contact bonding layer mentioned above.

  As a method of providing the mat layer and the adhesive layer as described above, the material constituting each layer is appropriately adjusted as a coating solution by adding an additive, a diluting solvent or the like as necessary, and the coating solution is conventionally known. The method of apply | coating and drying by a coating method is mention | raise | lifted.

  The above-described blindfold sheet of the present invention is mainly used by being attached to the outside or inside of a window glass or a partition, etc., but a mat film without an adhesive layer is hung outside or inside a transparent glass window. The same effect can be obtained.

  The following examples further illustrate the present invention. “Parts” and “%” are based on weight unless otherwise specified.

1. Production of Blindfold Sheet As a base material, a 50 μm thick PET film (HB3: Teijin DuPont) was used. It applied so that it might become thickness. Table 1 shows the coefficient of variation of the particle diameter and the average particle diameter of each pigment in each coating solution. The solid content of each coating solution was adjusted to 30%.

  Then, it dried and formed the mat layer and produced the blindfold sheet | seat of Examples 1-12 and Comparative Examples 1-6. The thickness of each mat layer is shown in Table 1 described later.

<Prescription of blindfold sheet coating solution>
・ Resin (solid content: 35.2%) 41.8 parts (916-257 Splash Clear TXF: Mikuni Paint Co., Ltd.)
・ Catalyst (solid content: 78.5%) 4.2 parts (D14-354: Mikuni Paint Co., Ltd.)
-9.0 parts of pigments listed in Table 1-35.0 parts of diluent solvent

  The pigment with a particle size variation coefficient of 32% and an average particle size of 5 μm shown in Table 1 is MB20X-5 of Sekisui Plastics Co., Ltd., and the particle size variation coefficient of 35% and the average particle size of 7 μm is Sekisui Plastics. MBX-8 from Kogyo Co., Ltd., GM1007S from Gantz Kasei Co., Ltd., a pigment with a particle size variation coefficient of 35% and an average particle size of 10 μm, and a pigment with a particle size variation coefficient of 10% and an average particle size of 3 μm from Toshiba Silicone Co., Ltd. MX1000KS, Soken Chemical Co., Ltd. was used as the pigment with Tospearl 130, a coefficient of variation in particle diameter of 10%, and an average particle diameter of 10 μm.

CV: Coefficient of variation of pigment particle diameter (%)
R: average particle diameter of pigment (μm)
T: thickness of the mat layer (μm)
R / T: Value obtained by dividing the average particle diameter of the pigment by the thickness of the mat layer (times)

2. Evaluation About the blindfold sheet obtained in each experimental example, the angle dependency of the specular gloss was evaluated by the following method. The results are shown in Table 2.

  From Table 2, it is recognized that the smaller the value obtained by dividing the maximum values of G45, G60, and G75 by the minimum value, the lower the angle dependency of the specular gloss.

Evaluation results

Maximum / minimum specular gloss: G45, G60 and G75 maximum values divided by minimum values

3. Discussion From Table 2, the following can be understood.
The blindfold sheets of Examples 1 to 12 contain a pigment, the variation coefficient of the particle diameter of the pigment is 20% or more, and a value obtained by dividing the maximum value of G45, G60, and G75 by the minimum value is 1.04 to 1 It was confirmed that the angle dependency of the specular gloss was low.
In particular, the blindfold sheets of Examples 9 to 12 have a large coefficient of variation in the particle diameter of the pigment as large as 35% and the large average particle diameter of the pigment as large as 10 μm. The divided value was as small as 1.04 to 1.21, and the angle dependency of the specular gloss could be further reduced.

  On the other hand, the blindfold sheets of Comparative Examples 1 to 6 have a coefficient of variation in pigment particle diameter that is outside of 20% or more, so that the value obtained by dividing the maximum value of G45, G60, and G75 by the minimum value is 1.47-2. It was confirmed that the mirror surface glossiness was highly angular dependent.

  Therefore, the superiority of the present invention including the pigment, the coefficient of variation of the particle diameter of the pigment, the average particle diameter of the pigment and the thickness of the mat layer is shown.

  As described above, in the blindfold sheets of all the examples, the value obtained by dividing the maximum value of G45, G60, and G75 by the minimum value is smaller than that of the blindfold sheet of the comparative example, and the angle dependency of the specular glossiness Was found to be low. Further, as an index of the blinding effect of the blindfold sheet, it was confirmed that a good blinding effect was obtained when the haze of the example was 60% or more.

DESCRIPTION OF SYMBOLS 1 ... Blindfold sheet 2 ... Light-transmitting base material 3 ... Matte layer 31 ... Binder resin 32 ... Pigment

Claims (3)

  A blindfolding sheet comprising a mat layer on a light-transmitting substrate, wherein the mat layer contains a binder resin and a pigment, and a coefficient of variation in particle diameter of the pigment is 20% or more.   The blindfold sheet according to claim 1, wherein the pigment has an average particle diameter of 4 to 12 μm.   The blindfold sheet according to claim 1 or 2, wherein the mat layer has a thickness of 4 to 8.5 µm.

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