JP5921182B2 - Blindfold sheet - Google Patents

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. The blindfold sheet (see, for example, Patent Document 1) has fine irregularities on the surface of the transparent 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 transparent substrate. There are several methods for applying the unevenness, and representative methods include sandblasting, in which sand is applied to the surface of the transparent substrate to roughen the surface of the transparent substrate, and a coating is applied to the surface of the transparent substrate to dry and a mat layer is provided. There is a construction method. 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 glossiness can be suppressed in the mat layer on the surface of the transparent substrate.

  As a result of intensive studies to solve the above problems, the present inventors have selected a pigment having a large average particle diameter and a pigment having a small average particle diameter as the pigment for the mat layer. Then, by setting the ratio of the content of the pigment having a large average particle diameter and the pigment having a small average particle diameter to a certain ratio, a blindfold sheet that suppresses the angle dependency of the specular glossiness in the mat layer on the surface of the transparent substrate. Found that you can get.

That is, the blindfold sheet of the present invention has a mat layer coated on a transparent substrate, the mat layer includes a binder resin and a pigment, and the mat layer has a thickness of 5.4 to 9.0 μm. The pigment includes a pigment having a larger average particle diameter than a thickness of the mat layer, and a pigment having a smaller average particle diameter, and the weight ratio of the content of the pigment having the larger average particle diameter to the content of the pigment having the smaller average particle diameter is 1: 0. .2 to 1: 1.2, and the maximum value of 45 degree specular gloss, 60 degree specular gloss and 75 degree specular gloss of the matte layer based on JIS-Z8741: 1997 is the minimum value. The divided value is 1.1 to 1.9 , and the haze of JIS K7136: 2000 is 75% or more .

  In the blindfold sheet of the present invention, the two types of pigments are characterized in that the average particle size of the pigment having a large average particle size is 2 to 6 times the average particle size of the pigment having a small average particle size. To do.

  In the blindfold sheet of the present invention, the average particle size of the pigment having a large average particle size is 1 to 2 times the thickness of the mat layer, and the average particle size of the pigment having a small average particle size is the mat. It is 0.2 to 0.6 times the thickness of the layer.

  Hereinafter, a pigment having an average particle diameter larger than the thickness of the mat layer may be expressed as a “large particle pigment”, and a pigment having an average particle diameter smaller than the mat layer thickness may be expressed as a “small particle pigment”.

  The specular gloss referred to in the present invention was measured using a gloss meter (trade name: VG-2000, Nippon Denshoku Industries Co., Ltd.) 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.

  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, in the mat layer on the surface of the transparent substrate, the angle dependency of the specular gloss can be suppressed.

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

  The blindfold sheet of the present invention has a mat layer on a transparent substrate, the mat layer includes a binder resin and a pigment, and the pigment has a pigment having a larger average particle diameter and a smaller pigment than the thickness of the mat layer. Wherein the weight ratio of the content of the pigment having a large average particle diameter and the content of the pigment having a small average particle diameter is 1: 0.2 to 1: 1.2. is there. Hereinafter, embodiments of each component will be described.

  The blindfold sheet according to the present invention has a matte layer on a transparent substrate.

  Various transparent plastic films and transparent glass can be used as the transparent substrate. 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 transparent substrates is not particularly limited, but is preferably about 6 μm to 2 mm, and more preferably about 12 μm to 200 μm. These preferably have a total light transmittance of 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, transparency, 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 when spherical resin particles are used, the angular dependence of the specular gloss can be further suppressed, and thus spherical resin particles are preferably used.

  In the present invention, the angle dependency of the specular gloss can be suppressed by including a pigment having a large particle size and a pigment having a small particle size as the pigment of the mat layer, and making the content ratio constant. 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, the mat layer containing only a large particle size pigment is adjacent to the large particle size pigment without any gaps, so that the surface is likely to have shallow irregularities (FIG. 1). On the other hand, the surface of the matte layer containing a large particle size pigment and a small particle size pigment in a certain ratio spreads the gap between the large particle size pigment and the large particle size pigment by adding the small particle size pigment, and the resulting large Both deep irregularities and small irregularities due to small particle size pigments tend to coexist (Fig. 2).

  As shown in FIG. 2, in a mat layer containing a large particle size pigment and a small particle size pigment at a certain ratio, light incident from an angle close to the horizontal direction is blocked by a large convex portion and reaches the opposite direction. It is difficult, and it is considered that the blocked light is absorbed by small unevenness or attenuated by irregular reflection. Therefore, it is considered that the angle dependency of the specular gloss can be suppressed by the presence of a moderately large and small matting agent and large and deep irregularities.

  Further, when the pigment of the mat layer is contained so that the weight ratio of the large particle size pigment is 1 and the weight ratio of the small particle size pigment is 0.2 or more, the addition of the small particle size pigment results in The gap between the large particle size pigments is widened, and the resulting large and deep irregularities can suppress the angle dependence of the specular gloss (FIG. 2). However, when the weight ratio of the small particle size pigment is 1.2 or more, large irregularities are formed, but the proportion of large particle sizes is reduced and the proportion of large irregularities is decreased. The dependency cannot be suppressed.

  As described above, in the present invention, the mat layer includes a pigment having a large particle diameter and a pigment having a small particle diameter, and the weight ratio of the content of the pigment having a large average particle diameter and the content of the pigment having a small average particle diameter is 1. When the ratio is 0.2 to 1: 1.2, there are large and deep irregularities and small irregularities on the surface of the mat layer, and the angle dependency of the specular gloss can be suppressed.

  In addition, it is thought that a large and deep unevenness | corrugation will be formed if only a large particle diameter pigment is reduced from the mat | matte layer (FIG. 1) containing many large particle diameter pigments. However, in that case, the ratio of the pigment in the coating film is reduced and the blinding effect is not sufficient, and since the small unevenness is not formed, the angle dependency of the specular glossiness cannot be suppressed from the present invention. .

  Furthermore, in this invention, it is preferable to make the average particle diameter of a large particle diameter pigment into 2-6 times the average particle diameter of a small particle diameter pigment. By setting it to 2 times or more, large and deep irregularities resulting from the difference in average particle size between the large particle size pigment and the small particle size pigment are likely to be present on the surface of the mat layer, and the angle dependency of the specular gloss is suppressed. It becomes easy to do. By setting it to 6 times or less, it becomes easy to prevent large-diameter pigments from adjoining each other and preventing large and deep irregularities from being formed on the surface of the mat layer (FIG. 3). The average particle size of the large particle size pigment is more preferably 3 to 5 times the average particle size of the small particle size pigment.

  Furthermore, the average particle size of the large particle size pigment is preferably 1 to 2 times the thickness of the mat layer. When the average particle size of the large particle size pigment is 1 or more times 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 a large particle size pigment is 2 times or less with respect to the thickness of a mat | matte layer, it will become easy to prevent drop | peeling of the pigment from the coating film.

  The average particle size of the small particle size pigment is preferably 0.2 to 0.6 times the thickness of the mat layer. When the average particle size of the small particle size pigment is 0.2 times or more with respect to the thickness of the mat layer, small irregularities are likely to occur on the surface of the mat layer. Also, when the average particle size of the small particle size pigment approaches the thickness of the mat layer, large and deep irregularities are less likely to occur, so the average particle size of the small particle size pigment is not more than 0.6 times the thickness of the mat layer Is preferred.

  Although the average particle size of each of the large particle size pigment and the small particle size pigment varies depending on the thickness of the mat layer, it cannot be generally stated. However, the average particle size of the large particle size pigment is preferably 6 to 12 μm, and preferably 8 to 10 μm. The average particle size of the small particle size pigment is more preferably 1 to 4 μm, and more preferably 2 to 3 μm.

  Further, the total content of the large particle size pigment and the small particle size pigment differs depending on the required concealability and glossiness, but cannot be generally stated, but is 20 to 80 parts by weight with respect to 100 parts by weight of the binder resin. Of 30 to 70 parts by weight, more preferably 40 to 60 parts by weight. By making the total content of the two types of pigments 20 parts by weight or more with respect to 100 parts by weight of the binder resin, the blinding effect can be sufficiently improved, and by making the total content 80 parts by weight or less, adhesion to the substrate is achieved. Can keep sex.

  As an index of the above-mentioned blindfold effect of the blindfold sheet, the haze of JIS K7136: 2000 is preferably 75% 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 average particle size and content 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 1-15 and Comparative Examples 1-7. 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 (78.5% solids) 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 large particle size pigment with an average particle size of 10 μm shown in Table 1 is MX1000KS from Soken Chemical Co., Ltd., and the small particle size pigment with an average particle size of 3 μm is Tospearl 130 from Toshiba Silicone Co., Ltd. Is MBX-8SS manufactured by Sekisui Plastics Co., Ltd., and Tospearl 120 manufactured by Toshiba Silicone Co., Ltd. is used as a small particle size pigment having an average particle size of 2 μm.

R1: Average particle size (μm) of large particle size pigment
R2: Average particle size of small pigment (μm)
R1 / R2: Value obtained by dividing the average particle size of the large particle size pigment by the average particle size of the small particle size pigment (times)
W1: Content (part) of large particle size pigment
W2: Content of small particle size pigment (parts)
Ratio of W1 and W2: Weight ratio of content of large particle size pigment and content of small particle size pigment T: Thickness of mat layer (μm)
R1 / T: value obtained by dividing the average particle size of the large particle size pigment by the thickness of the mat layer (times)
R2 / T: Value obtained by dividing the average particle size of the small particle size 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.

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 15 include a large particle size pigment and a small particle size pigment, and the weight ratio of the large particle size pigment content to the small particle size pigment content is 1: 0.2 to 1: The value obtained by dividing the maximum value of G45, G60, and G75 by the minimum value was as small as 1.1 to 1.9, and it was recognized that the mirror surface glossiness has low angle dependency.
In particular, in the blindfold sheets of Examples 1 to 6 and 10 to 12, the average particle size of the large particle size pigment is 1.4 times to 1.9 times larger than the thickness of the mat layer, and the small particle size pigment Since the average particle diameter of A is 0.4 to 0.6 times larger than the thickness of the mat layer, the value obtained by dividing the maximum value of G45, G60 and G75 by the minimum value is as small as 1.1 to 1.5. In particular, the angle dependency of the specular gloss was low and was found to be excellent.

  On the other hand, in the blindfold sheets of Comparative Examples 1 to 7, the weight ratio of the large particle size pigment content to the small particle size pigment content deviates from 1: 0.2 to 1: 1.2. And the value obtained by dividing the maximum value of G75 by the minimum value was as large as 1.5 to 2.0, and it was confirmed that the angle dependency of the specular gloss was high.

The values obtained by dividing the maximum values of G45, G60, and G75 of the blindfold sheets of Examples 7 to 9, 12, 14, and 15 by the minimum values are larger than those of Comparative Examples 1 to 4.
However, the ratio of the average particle size of the large particle size pigment to the small particle size pigment, the ratio of the average particle size of the large particle size pigment to the thickness of the mat layer, and the ratio of the average particle size of the small particle size pigment to the thickness of the mat layer Examples 7-9 and Comparative Example 5, Example 12, Comparative Example 6 and Example 14, except that the weight ratio of the large particle size pigment content and the small particle size pigment content is different, with the same items. When the value obtained by dividing the maximum values of G45, G60, and G75 by the minimum value between 15 and Comparative Example 7 is compared, the value of Example is smaller.
Therefore, the superiority of the present invention including two types of pigments, a large particle size pigment and a small particle size pigment, in which the weight ratio of these two types of pigments is in a specific range 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 blindfold effect of the blindfold sheet, it was confirmed that a good blindfold effect was obtained when the haze of the example was 75% or more.

DESCRIPTION OF SYMBOLS 1 ... Sheet for blindfold 2 ... Transparent base material 3 ... Matte layer 31 ... Binder resin 32 ... Large particle size pigment 33 ... Small particle size pigment

Claims (3)

A mat layer coated on a transparent substrate, the mat layer including a binder resin and a pigment, and the mat layer has a thickness of 5.4 to 9.0 μm; The weight ratio of the content of the pigment having a large average particle diameter and the content of the pigment having a small average particle diameter is 1: 0.2 to 1: 1.2. The value obtained by dividing the maximum values of the 45 ° specular gloss, 60 ° specular gloss and 75 ° specular gloss by the minimum value of the specular gloss based on JIS-Z8741: 1997 of the matte layer is 1.1-1. The blindfold sheet is characterized in that the haze of JIS K7136: 2000 is 75% or more .   2. The blindfold sheet according to claim 1, wherein the two types of pigments have an average particle diameter of a pigment having a large average particle diameter of 2 to 6 times an average particle diameter of a pigment having a small average particle diameter.   The average particle diameter of the pigment having a large average particle diameter is 1 to 2 times the thickness of the mat layer, and the average particle diameter of the pigment having a small average particle diameter is 0.2 to the thickness of the mat layer. The blindfold sheet according to claim 1 or 2, wherein the sheet is 0.6 times.

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