JPH0578544A - Heat-reflecting plate - Google Patents

Abstract

PURPOSE:To provide a methacrylic resin plate excellent in light transmittance and heat-reflecting effect. CONSTITUTION:The objective plate is prepd. by forming a transparent methacrylic resin layer on both sides of a resin layer consisting of 100 pts.wt. methacrylic resin and 0.01 0.3 pt.wt. mica coated with titanium oxide.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a heat ray reflector plate, and more particularly to a translucent heat ray reflector plate made of a methacrylic resin composition.

[0002]

2. Description of the Related Art As a conventional heat ray reflector, for example, a heat ray shield plate (Japanese Utility Model Publication No. 63-106735) in which a scale-like inorganic pigment having metallic luster is dispersed and mixed, a heat ray reflection film on a plate-shaped resin glass. Adhered heat ray reflective resin glass (Japanese Patent Laid-Open No. 61-277437) and the like have been proposed.

[0003]

However, the above-mentioned proposed heat ray blocking plate can provide a heat ray blocking plate suitable for a roof plate material, but has a drawback that it hardly transmits visible light, and a heat ray reflecting resin. The glass requires a heat ray reflective film, which requires complicated steps such as an adhesion step and is costly, and has a problem in that the film peels due to aging.

Therefore, it is an object of the present invention to provide a methacrylic resin plate having a high light transmittance and an excellent heat ray reflection effect, that is, a methacrylic resin plate having a brightness and a coolness. ..

[0005]

Means for Solving the Problems The inventors of the present invention have conducted extensive studies to achieve the above-mentioned object, and as a result, by incorporating a small amount of titanium oxide-coated mica in methacrylic resin, the heat ray reflection effect and the light transmittance are excellent. The present invention has been completed by finding that a plate-like body having high brightness and a sense of brightness can be obtained.

That is, according to the present invention, the above-mentioned object is achieved by a heat ray reflection plate-like body made of a resin composition containing 0.01 to 0.3 parts by weight of mica coated with titanium oxide in 100 parts by weight of methacrylic resin. can do.

Further, according to the present invention, the above object is to provide a transparent methacrylic resin on at least one surface of a resin layer containing 0.01 to 0.3 parts by weight of mica coated with titanium oxide in 100 parts by weight of methacrylic resin. It can also be achieved by a heat ray reflector having a layer.

The present invention will be described in detail below.

The methacrylic resin used in the present invention is a homopolymer of methyl methacrylate or a copolymer containing methyl methacrylate as a main component. The molecular weight of these polymers is not particularly limited, but it is preferably within the range capable of melt extrusion from the viewpoint of productivity. The methacrylic resin can be produced by a known method such as bulk polymerization and suspension polymerization, and a molecular weight modifier, a catalyst and the like are appropriately selected and used in the polymerization.

The mica coated with titanium oxide used in the present invention is a synthetic mica or natural mica coated with titanium oxide, and commercially available iridin (manufactured by A-Merck) can be preferably used. The coating amount of titanium oxide is usually 30 to 60 with respect to the coated mica.
The amount is such that the weight percentage is preferably 40 to 50 wt%.
The particle size of titanium oxide-coated mica is usually an average particle size of 5
˜100 μ, preferably 10 to 60 μ.

The content of mica coated with titanium oxide is
0.01-0.3 per 100 parts by weight of methacrylic resin
The amount is preferably 0.02 to 0.1 part by weight, more preferably 0.03 to 0.09 part by weight. The content is 0.
When the amount is less than 01 parts by weight, the heat ray reflection effect is not sufficiently obtained, while when the amount is more than 0.3 parts by weight, the total light transmittance is lowered and the brightness is insufficient, which is not preferable.

The heat ray reflective plate-like body of the present invention comprising a resin composition containing mica in which methacrylic resin is coated with titanium oxide is formed, for example, by coating a predetermined amount of titanium oxide in a monomer mainly composed of methyl methacrylate. Casting polymerization by adding mica, and applying vibration in the surface direction immediately before the completion of polymerization to mold, or uniformly mixing a predetermined amount of titanium oxide-coated mica on methacrylic resin pellets by a known mixing means such as a high-speed mixer. Then, the obtained mixture can be obtained as it is or by pelletizing it once and then subjecting it to injection molding, extrusion molding or the like. As the shape of the heat ray reflective plate, a planar shape,
The shape may be a curved surface or the like. Further, after processing, it can be formed into any shape such as a spherical shape or a corrugated plate shape.

If necessary, auxiliary components such as dyes and pigments, fillers, heat stabilizers, ultraviolet absorbers and antistatic agents may be added to the heat ray reflector.

Further, as a preferred embodiment of the heat ray reflective plate-like body of the present invention, one having a transparent methacrylic resin layer on at least one surface of a resin layer containing mica in which methacrylic resin is coated with titanium oxide is mentioned. it can. More specifically, for example, in FIG. 1, a titanium oxide-coated mica-containing resin layer (A) provided with a transparent methacrylic resin layer (B) on one side, and in FIG. 2 a resin layer (B) on both sides of the resin layer (A). ) Are provided respectively. The transparent methacrylic resin layer (B) is a layer of methacrylic resin having transparency,
It may contain dyes and pigments, ultraviolet absorbers, stabilizers and the like.
By providing the resin layer (B), it is possible to improve the smoothness or weather resistance of the heat ray reflection plate-like body and adjust the color tone of the heat ray reflection plate like body. The resin layer (B) is usually 0.0 with respect to the thickness of the heat ray reflective plate-like body of about 2 to 10 mm.
Thickness ranging from 3 mm to 1 mm, preferably 0.05 m
Thicknesses ranging from m to 0.5 mm are used. The heat ray reflective plate-shaped body composed of two or more resin layers can be efficiently manufactured by a coextrusion molding method.

[0015]

EXAMPLES The present invention will be specifically described below with reference to examples, but the present invention is not limited to these. In addition, the evaluation methods in Examples are as follows (1) to
It carried out by the method of (3).

(1) Total light transmittance According to ASTM D-1003, Suga Test Instruments Co., Ltd.
It is a value measured by an integrating sphere type light transmittance measuring device (direct reading type haze computer) and is expressed in%.

(2) Solar energy acquisition rate U340 manufactured by Hitachi Ltd. in accordance with JIS R3106
0-type self-recording spectrophotometer, 340-180 with integrating sphere
The distance between 0 mm was measured, and the average solar radiation transmittance (T) and the average solar radiation reflectance (R) were determined (excluding long wavelengths of 1800 mm or more because they have little influence on the object of the present invention). The solar radiation absorption rate (A) is A = 100− (T +
R). From the solar radiation transmittance (T) and the solar radiation absorption rate (A) thus obtained, the solar energy acquisition rate was calculated by the following formula. T + A / 3

(3) Rate of temperature rise suppression A 10 mm thick plywood board was used to prepare a box with a side of 500 mm and one side open, and all inner surfaces of the box were covered with a black paper lining heat insulating material. did. The open side of the experiment box is covered with a colorless and transparent acrylic plate, and a temperature measuring part (using a K type thermocouple with a wire diameter of 0.3 mm) is installed at a position 6 cm away from the acrylic plate inside the box, and this is a sunny day. At 45 degrees above the ground, it is installed so that it faces the sun in the middle of Nichinan, and the temperature inside the box is measured. For the other test plates, cover the open surface of the experimental box and measure the temperature inside the box in the same manner.
In addition to this measurement, the temperature of the outside air in the shaded area 1 m above the ground is measured. Using the temperature thus obtained, the value obtained by the following formula was expressed in%.

[(A−B) / (A−G)] × 100 where A, B and G indicate the following temperatures. A: Maximum temperature inside the box when covered with an acrylic plate B: Maximum temperature inside the box when covered with a test plate C: Temperature of the outside air at the maximum temperature

Experimental Examples 1-2 Weight average molecular weight 1 copolymerized with 6% by weight of ethyl acrylate
100 parts of 20,000 methacrylic resin, titanium oxide coated mica Iriodim 219 Rutile
Lilac Pearl was added and mixed in an amount shown in Table 1 to the intermediate layer, and the methacrylic resin containing 0.01% by weight of an ultraviolet absorber was coextruded on both sides of the intermediate layer with a T-die extruder to form a three-layer structure sheet. Was molded. The evaluation results of the obtained molded sheet are shown in Table 1. In addition, although the appearance of each of the obtained sheets was close to that of the milk half plate, since the sheet was not a perfect diffusion type, the movement of the product was in a state that was better understood than that of the milk half plate.

Comparative Examples 1 to 3 Transparent acrylic plate (Kuraray Co., Ltd .: Paragrass), half mirror (Teijin Leftel ZC-05-T attached to a 5 mm thick paragrass) and milk half plate ((Co)) Kuraray Co., Ltd .: COMOGRAS 432L) was used and evaluated in the same manner as in Example 1, and the results are also shown in Table 1.

[0022]

[Table 1]

Examples 3 to 4 The plates obtained in Examples 1 and 2 were exposed to the sunshine weather meter for 2000 hours. After the test, there is no change in the appearance of any of the plates, and the decrease in total light transmittance is 1
It was within%.

[0024]

As described above, the heat ray reflector plate of the present invention contains a small amount of titanium oxide-coated mica in the methacrylic resin layer or has a transparent methacrylic resin layer on at least one surface of this layer. As a result, it is possible to obtain not only an excellent heat ray reflection effect (coolness) but also a high light transmittance and a sense of brightness. Therefore, the heat ray reflective plate-like body of the present invention is suitable for daylighting windows, carport roofs, arcade daylighting parts, automobile sunroofs, sun visors, etc., and exhibits energy-saving effects from both indoor lighting and temperature control. It

[Brief description of drawings]

FIG. 1 is a cross-sectional view of a heat ray reflective plate-shaped body that is a preferred embodiment of the present invention.

FIG. 2 is a cross-sectional view of a heat ray reflective plate-like body that is a preferred embodiment of the present invention.

[Explanation of symbols]

A: Methacrylic resin layer containing titanium oxide-coated mica B: Transparent methacrylic resin layer

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁵ Identification code Internal reference number FI Technical display location E04B 1/76 N 2118-2E E06B 5/00 B 7806-2E

Claims (2)

[Claims] 1. A heat ray reflecting plate made of a resin composition containing 0.01 to 0.3 part by weight of mica coated with titanium oxide in 100 parts by weight of a methacrylic resin. 2. A heat ray characterized by having a transparent methacrylic resin layer on at least one surface of a resin layer containing 0.01 to 0.3 parts by weight of mica coated with titanium oxide in 100 parts by weight of methacrylic resin. Reflective plate.