JP3348992B2 - Polycarbonate daylight - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a daylighting material, and more particularly to a daylighting material mainly composed of polycarbonate resin.

[0002]

2. Description of the Related Art Japanese Utility Model Laid-Open No. 2-144425 discloses a light-shielding synthetic resin plate using a polycarbonate resin. The light-shielding synthetic resin plate described in this publication is devised so as to exhibit high light-shielding properties without reducing mechanical strength such as impact resistance of the polycarbonate resin as much as possible. As a measure, a skin layer made of an acrylic film containing a colorant with excellent light-hiding properties such as an inorganic pigment is laminated on a polycarbonate resin base material containing no additives or containing a small amount of a colorant such as a dye. (Lamination and integration) is selected. In other words, the technology described in this publication is based on the fact that the mechanical strength of a polycarbonate resin having the property that the mechanical strength is extremely reduced when an inorganic pigment such as titanium oxide is mixed is excellent. It can be said that it is based on the idea of utilizing the high light concealing property of the synthetic resin skin layer laminated on the polycarbonate resin substrate to the synthetic resin plate as a product.

[0003]

By applying the concept of the technology described in the above-mentioned publication, the content of inorganic pigments in the laminated skin layer is reduced to adjust the light concealing property of the skin layer. For example, it is possible to imagine obtaining a translucent polycarbonate light-emitting material without much difficulty.

[0004] However, in order to produce a synthetic resin plate as described in the above publication, a polycarbonate resin base material and a skin layer separately extruded from an extruder are required.
Since it is necessary to perform lamination and integration after extrusion, the manufacturing process becomes more complicated and equipment costs and manufacturing costs are inevitably high.

The present invention has been made in view of the above circumstances, and in a synthetic resin layer mainly composed of a polycarbonate resin, if the refractive index of light between the polycarbonate resin and a different kind of synthetic resin mixed with the polycarbonate resin is different, the difference is caused. An object of the present invention is to provide a polycarbonate daylighting material in which the light transmittance of the polycarbonate daylighting material is adjusted to such an extent that the daylighting material becomes translucent by utilizing a phenomenon that light is refracted in a layer.

[0006]

According to a first aspect of the present invention, there is provided a polycarbonate light-receiving material having a structure containing no inorganic pigment and comprising a mixture of a polycarbonate resin and 15% by weight or less of an acrylic resin. A synthetic resin film colored in chromatic or achromatic color and having a total light transmittance of 5 to 20% is laminated to have a total light transmittance of 15% or more.

It is desirable that such a polycarbonate daylighting material adopt a configuration in which it is formed in a corrugated plate shape as described in claim 2.

[0008]

[Function] The polycarbonate resin not only has excellent mechanical strength such as impact resistance, but also exhibits high translucency.
The plate material is widely known as a transparent plate for lighting. However, if the polycarbonate resin is mixed with an inorganic pigment such as titanium oxide having excellent light-hiding properties to reduce the light-transmitting property and thereby impart semi-transparency, the material deteriorates, and over time, the initial mechanical properties are reduced. The strength cannot be maintained.

On the other hand, in the present invention, a polycarbonate daylighting plate is obtained by mixing an acrylic synthetic resin with a polycarbonate resin. Methyl methacrylate resin itself, which is a typical example of an acrylic synthetic resin, exhibits a higher transparency than a polycarbonate resin, but when the methyl methacrylate resin is mixed in the polycarbonate resin layer, the light-receiving plate is formed. Light is refracted in a synthetic resin layer made of a polycarbonate resin and an acrylic synthetic resin, and the phenomenon causes the polycarbonate light-collecting material to exhibit a frosted glass-like translucency. In the present invention, the addition amount of the acrylic synthetic resin is 15% by weight or less, preferably 1% by weight, based on 100% by weight of the polycarbonate resin.
Since the content is suppressed to 0% by weight or less, the mechanical strength of the polycarbonate resin accompanying the addition of the acrylic synthetic resin does not decrease so much.

In the case of laminating a chromatic or achromatic synthetic resin film, this may occur due to the fact that the polycarbonate resin and the acrylic synthetic resin are not in a uniform mixed state. “Color unevenness” is apparently eliminated by the synthetic resin film. In particular, when a film having a total light transmittance of 5 to 20% is used, "color unevenness" is completely eliminated in appearance.

[0011]

1 shows a corrugated polycarbonate daylighting material A according to an embodiment of the present invention. This daylighting material A has smoothly curved mountain-shaped ridges 1 at equal pitches,
It has a smoothly curved valley-shaped concave strip 2 between two adjacent convex strips 1 and 1. As shown in FIG. 1 in an enlarged manner, the daylighting material A has a two-layer structure including a base material 5 and a skin layer 8 laminated on one surface of the base material 5. The base material 5 is made of a polycarbonate resin-based synthetic resin obtained by mixing an acrylic synthetic resin such as methyl methacrylate (hereinafter, referred to as MMA) with a polycarbonate resin.
The skin layer 8 is made of a chromatic or achromatic acrylic synthetic resin, for example, an MMA film.

By the way, the polycarbonate resin itself has excellent properties such as excellent transparency and mechanical strength such as impact resistance, so that it is widely used as a transparent material for daylighting. . MMA also
Since it has an inherent property that transparency is superior to polycarbonate resin and good weather resistance, it is frequently used as a skin layer (surface protective layer) of a daylighting material or the like.

In the polycarbonate daylighting material A of the embodiment, the substrate 5 is composed of a synthetic resin layer mainly composed of a polycarbonate resin mixed with MMA. Resin and MM
A) has excellent translucency in each case. However, when MMA is mixed in the polycarbonate resin, the light refraction index of the two is different, so that light is complicatedly refracted in the synthetic resin layer forming the base material 5, and apparently, the base material 5 has a frosted glass translucency. The substrate 5 does not need to be colored, but may be colored by adding a small amount of a dye or pigment to the polycarbonate resin so as not to lower the mechanical strength of the polycarbonate resin.

Although the substrate 5 can be used as a translucent material even when the skin layer 8 is not laminated,
Forming the chromatic or achromatic skin layer 8 has the following advantages. That is, the base material 5 is MMA
When the mixed state of the MMA and the polycarbonate resin is not uniform, the degree of translucency becomes uneven due to the mixed state, and the transparencies differ in the daylighting material. A part, that is, “color unevenness” may appear, in which case the “color unevenness” lowers the commercial value. However, in the daylighting material A of the embodiment, the skin layer 8 laminated on one surface of the base material 5 plays a role of covering and hiding the above “color unevenness”. There is an advantage that "unevenness" and "color unevenness" between different light-collecting materials A are eliminated, and "color unevenness" does not reduce the commercial value. The coloring of the skin layer 8 is desirably white, but may be colored in another achromatic color such as gray or a chromatic color such as brown smoke or blue. When the total light transmittance of the synthetic resin film is set to 5 to 30%, "color unevenness" is completely covered and hidden by the synthetic resin film, so that it is preferably adopted.

As described above, the polycarbonate resin has an inherent property of being excellent in mechanical properties such as impact resistance. However, when MMA is mixed with such a polycarbonate resin, the amount of MMA varies depending on the amount of MMA. May impair the excellent mechanical properties of the polycarbonate resin. Further, in order to satisfy the use as a daylighting material, it is required that the total light transmittance is not less than a certain value.

Therefore, the present inventor has found that, in the base material 5, the relationship between mechanical properties such as impact resistance, bending strength and tensile strength and the amount of added MMA, and the total light transmittance and MMA
The relationship with the amount added was investigated, and the results shown in Table 1 were obtained. FIG. 2 shows the relationship between the total light transmittance and the amount of MMA added in Table 1, and FIG. 3 shows the relationship between the impact strength and the amount of MMA added.
FIG. 4 shows the relationship between the bending strength and the amount of MMA added, and FIG. 5 shows the relationship between the tensile strength and the amount of MMA added. In this study, the physical properties of each sample formed by adding different amounts of MMA pellets to the polycarbonate resin pellets and forming them into a plate shape were examined. The optical characteristics are values for a flat plate having a thickness of 1 mm.

[0017]

[Table 1]

Translucent daylighting materials used for roofs and blinds of buildings are required to have a total light transmittance of a certain value or more and mechanical strength as a polycarbonate resin. Therefore, when the amount of MMA to be added to the polycarbonate light-emitting material of the above sample was determined in consideration of the total light transmittance and the mechanical strength required for the translucent light-emitting material used for the above application, Table 1 was obtained.
And FIG. 2 or FIG.
When the amount of MA added is 15% by weight or less, 90 kg · cm / cm ² or more in impact strength can be provided,
It retains the impact strength characteristic of polycarbonate resin. It can be seen that a total light transmittance of 15% or more can be provided. It has been found that when the addition amount of MMA is 15% by weight or less in terms of bending strength and tensile strength, the required quality as a polycarbonate resin can be satisfied. If the added amount of MMA is more than 15% by weight, it is impossible to secure 90 kg · cm / cm ² or more in impact strength, and it is impossible to maintain the quality as a polycarbonate resin daylighting material. Becomes too low to maintain the quality as a daylighting material.
Therefore, the amount of MMA added to 100% by weight of the polycarbonate resin must be 15% by weight or less. Further, as can be seen from FIG. 3, when the amount of MMA added is more than 10% by weight, the impact strength sharply decreases, so that the amount of MMA added should preferably be suppressed to 10% by weight or less. In addition, those having an added amount of MMA of more than 15% by weight and having a low total light transmittance can be used for applications requiring such optical characteristics, for example, for a light-shielding plate.

Next, MMA was applied to the polycarbonate resin.
Was mixed with 7% by weight, and a 0.7 mm-thick flat base material was extruded. The resulting corrugated sheet was measured for physical properties. Obtained. Also,
The same measurement was performed on the polycarbonate light-emitting material described in FIG. 1, that is, a polycarbonate corrugated-sheet light-emitting material in which a skin layer made of a white MMA film having a thickness of 50 μm was laminated on one surface of a base corrugated sheet. Also shown in the table. Note that the laminated polycarbonate corrugated daylighting material is formed by laminating a flat base material and an MMA film into a corrugated plate shape. Further, as a comparative example, the measured values of a daylighting material molded into a corrugated plate only with a polycarbonate resin are also shown in the same table.

[0020]

[Table 2]

In Table 2, the optical characteristics are indicated by a haze meter, and the presence or absence of cracks reaching the back surface when a 1 kg weight (ball 2) is dropped based on the impact strength JIS K6735, and the bending strength based on JIS K6735. 5 spans
Measure the amount of flexure when a load of 294N is applied with a load of 00mm, and withstand the load, pass the hook bolts through the bolt holes provided at four points with a span of 500mm and gradually increase the concentrated load applied to the center. Then, the value of the load when the bolt hole started to break at the hook bolt was measured.

The corrugated sheet made of only the base material (a polycarbonate corrugated sheet light-emitting material having no skin layer) had a high haze of 91.2% and exhibited translucency such as white turbidity. However, in the corrugated sheet in which the skin layer was laminated on the base material, the haze was almost the same, but only the white color of the skin layer was observed, and the white turbidity of the base material was not visually recognized. Further, the corrugated plate having only the base material had a total light transmittance of 55.7%, which was almost half of the light, and was sufficiently usable as a daylighting material. Then, the total light transmittance of the laminated corrugated sheet was greatly reduced to 14.2% due to the influence of the total light transmittance of the MMA film, but it had a daylighting property that could withstand actual use. Since the light transmittance of the laminated corrugated sheet changes depending on the total light transmittance of the MMA film, a test using various light transmittances resulted in a total light transmittance of the white MMA film of 10 to 30%. Thickness 50-100μ
It was found that if it was m, translucency which could be used as a daylighting material was obtained without impairing the mechanical strength as a corrugated sheet. Note that a white MMA film can be obtained by adding a white pigment such as titanium oxide. The corrugated sheet made of only the base material and the laminated corrugated sheet show the same value of the impact strength, bendability, and load resistance as the corrugated sheet with the general polycarbonate corrugated sheet (comparative example). It turns out that it can withstand use.

In FIG. 1, although only one side of the substrate 5 is laminated with the MMA film,
Both surfaces of the substrate 5 may be laminated with an MMA film.

[0024]

The polycarbonate daylighting material according to the present invention does not control the light transmittance of the polycarbonate resin by utilizing the light concealing property of an inorganic pigment or the like, but is an acrylic synthetic material having compatibility with the polycarbonate resin. A resin is mixed with a polycarbonate resin to form a synthetic resin layer serving as the daylighting material, and a semi-transparency is obtained by utilizing the irregular reflection phenomenon of light in the synthetic resin layer. Since the mixing amount is 15% by weight or less with respect to the polycarbonate resin, the polycarbonate light-emitting material as a product is hardly reduced in mechanical strength such as impact resistance inherently possessed by the polycarbonate resin. There is an advantage that can be used as it is. Furthermore, the polycarbonate daylighting material according to the present invention has the same mechanical performance as a corrugated sheet made of only polycarbonate resin even if its shape is a corrugated sheet, and has a certain shielding performance exhibited by the corrugated sheet shape. There is a practical advantage as a corrugated sheet lighting material.

Further, in a polycarbonate daylighting material laminated with a chromatic or achromatic colored synthetic resin film, a single sheet of the daylighting material alone supplied as a product and an acrylic synthetic resin are used. The “color unevenness” of the synthetic resin layer and the “color unevenness” between the different light-receiving materials are apparently eliminated, so that the product quality can be improved. If the total light transmittance of the synthetic resin film is set to 10 to 30%, the above-mentioned "color unevenness" is completely eliminated, and the synthetic resin film can be used as a daylighting material.

[Brief description of the drawings]

FIG. 1 is an explanatory diagram of a corrugated polycarbonate daylighting material according to an embodiment of the present invention.

FIG. 2 is a table showing the relationship between the total light transmittance and the amount of MMA added for a corrugated polycarbonate daylighting material according to an example of the present invention.

FIG. 3 is a table showing the relationship between the impact strength and the amount of MMA added for a corrugated polycarbonate daylighting material according to an example of the present invention.

FIG. 4 is a table showing the relationship between bending strength and the amount of MMA added for a corrugated polycarbonate daylighting material according to an example of the present invention.

FIG. 5 is a table showing the relationship between the tensile strength and the amount of MMA added for a corrugated polycarbonate daylighting material according to an example of the present invention.

[Explanation of symbols]

 A Polycarbonate daylighting material 5 Base material 8 Skin material

──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Kikuchi, 2-3-13 Azuchicho, Chuo-ku, Osaka City Inside Takiron Co., Ltd. (72) Naoki Yabuta 2-3-3, Azuchicho, Chuo-ku, Osaka City (56) References JP-A-5-17599 (JP, A) JP-A-6-198823 (JP, A) JP-A-62-131056 (JP, A) JP-A-1-154940 (JP) JP, A) JP-A-4-359954 (JP, A) JP-A-59-98031 (JP, U) JP-A-2-144425 (JP, U) (58) Fields investigated (Int. Cl. ⁷ , (DB name) C08J 3/00-3/28

Claims (2)

(57) [Claims] 1. A chromatic or achromatic colored light beam having a total light transmittance of 5 to 5% on one surface of a substrate containing no inorganic pigment and comprising a mixture of a polycarbonate resin and 15% by weight or less of an acrylic resin. A polycarbonate daylighting material having a total light transmittance of 15% or more by laminating a 20% synthetic resin film. 2. The polycarbonate daylighting material according to claim 1, which is formed into a corrugated sheet shape.