JPH0853555A - Heat ray-reflecting sheet and its production - Google Patents

Abstract

PURPOSE:To obtain the subject sheet which is low in cost, excellent in impact strength and heat ray-reflecting properties by making a sheet from an acrylic resin composition containing heat ray-reflecting particles in an acrylic resin containing a crosslinked elastomer. CONSTITUTION:An acrylic resin (A) containing a crosslinked elastomer (B) consisting of a copolymer of (i) an alkyl acrylate and (ii) at least one kind of crosslinkable monomer selected from the group of divinylbenzene, diallyl phthalate, mono- or poly-ethylene glycol dimethacrylate, allyl methacrylate and triallyl cyanurate is impregnated with heat ray-reflecting particles (C) (preferably titanium oxide-coated mica). The resultant acrylic resin composition is shaped to a sheet preferably having a thickness of 10-300mum to afford the aimed sheet.

Description

Detailed Description of the Invention

[0001]

FIELD OF THE INVENTION The present invention relates to a heat ray reflective sheet,
More specifically, it relates to a heat ray reflective sheet made of an acrylic resin composition and a method for producing the same.

[0002]

2. Description of the Related Art Conventionally, as a heat ray reflecting material, for example, a heat ray reflecting resin glass obtained by adhering a heat ray reflecting film to a plate-like resin glass (Japanese Patent Laid-Open No. 61-277437), a scale-like inorganic pigment having metallic luster. Dispersion-mixed heat ray reflector (Japanese Utility Model Publication No. 63-106735), heat ray reflector containing polycarbonate resin coated with mica coated with titanium oxide (JP-A-2-173060), 100 parts by weight of methacrylic resin and titanium oxide. Mica coated with 0.0
A heat ray reflecting plate-shaped body (Japanese Patent Application Laid-Open No. 5-78544) made of a resin composition containing 1 to 0.3 part by weight, and 0.1 part of mica obtained by coating 100 parts by weight of transparent synthetic resin with titanium oxide.
A heat ray reflector having a three-layer structure having transparent synthetic resin layers on both sides of a resin layer containing 10 parts by weight (Japanese Patent Laid-Open No. 5-13.
No. 8833) has been proposed.

[0003]

However, the heat ray reflective resin glass requires a heat ray reflective film in which a metal such as aluminum is vapor-deposited on the film, and a complicated step such as an adhering step is required, resulting in high cost. However, there is a problem that the film peels due to aging. In addition, the heat ray reflective film in which a metal is vapor-deposited on a film has not only the ability to reflect light but also the ability to absorb it. When receiving light from sunlight or electric light, the film itself absorbs the energy of light. You will have a fever. When this film is used by adhering it to a resin sheet such as polycarbonate, PMMA, PVC, etc., when the film is exposed to light, the film absorbs heat and only the film surface expands,
The sheet will be warped or distorted. In addition, a heat ray reflection plate in which heat ray reflection particles are mixed with a transparent resin (Shokai Sho 63-1
No. 06735, JP-A-2-173060, JP-A-5-78544), for example, 300
It is difficult to form a thin film having a thickness of μm or less, and mechanical strength such as impact resistance is not sufficient. Furthermore, the sheet disclosed in JP-A-5-138833 is obtained by coextruding three layers, It has become a cost. An object of the present invention is to provide a sheet that is inexpensive, has good mechanical strength, and has excellent heat ray reflection performance, and a method for producing the sheet.

[0004]

Means for Solving the Problems As a result of intensive studies to achieve the above object, the present inventors have introduced impact resistance by introducing a crosslinked elastic body component into an acrylic resin to impart flexibility. In addition, a large amount of heat ray-reflecting particles can be blended, and as a result, a sheet having excellent impact resistance and heat ray-reflecting performance can be obtained, and a sheet having a thickness of 300 μm or less can be prepared. They have found the present invention and completed the present invention.

That is, the first aspect of the present invention is to provide a heat ray-reflecting sheet obtained by adding heat ray-reflecting particles to an acrylic resin containing a crosslinked elastic body.

A second aspect of the present invention is a method for producing a heat-reflecting sheet, which is characterized in that an acrylic resin composition containing a heat ray-reflecting particle in an acrylic resin containing a crosslinked elastic body is formed into a sheet. It is the content.

Hereinafter, the present invention will be described in detail. The acrylic resin containing the crosslinked elastic body used in the present invention is an acrylic resin composed of a methacrylic acid alkyl ester homopolymer or a copolymer of a methacrylic acid alkyl ester and another monomer copolymerizable therewith. Crosslinked elastic body component (B) obtained by crosslinking the resin component (A), an acrylic acid alkyl ester, and optionally other monomer copolymerizable therewith, and a crosslinkable monomer.
Consists of The component (A) and the component (B) may be polymerized separately, and the obtained latex or resin may be blended, or the component (B) may be polymerized and then continuously added in the presence of the component (B). The component (A) may be polymerized. Tg of the crosslinked elastic body alone is preferably 0 ° C. or lower, more preferably −30 ° C.
The following gives good physical properties. The content of the crosslinked elastic body is preferably in the range of 10 to 45% by weight. If it is less than 10% by weight, the effect of imparting flexibility is insufficient and it becomes difficult to blend a large amount of heat ray reflective particles. On the other hand, 45% by weight
If it exceeds, it becomes difficult to form a sheet by the extrusion method (T-die method, inflation method) and the calender method.

In the acrylic resin component (A), other monomers copolymerizable with the methacrylic acid alkyl ester include vinyl halides such as vinyl chloride, vinyl cyanide such as acrylonitrile, and vinyl esters such as vinyl acetate. , Aromatic vinyl derivatives such as styrene, vinylidene halides such as vinylidene chloride, acrylic acid and salts thereof, acrylic acid alkyl esters and derivatives thereof, methacrylic acid and salts thereof, methacrylic acid alkyl ester derivatives, and the like, These are used alone or in combination of two or more.

In the crosslinked elastic component (B), other monomers copolymerizable with the alkyl acrylate include vinyl halide such as vinyl chloride, vinyl cyanide such as acrylonitrile, vinyl ester such as vinyl acetate. , Aromatic vinyl derivatives such as styrene, vinylidene halides such as vinylidene chloride, acrylic acid and salts thereof, acrylic acid alkyl ester derivatives, methacrylic acid and salts thereof, methacrylic acid alkyl esters and derivatives thereof, and the like, These are used alone or in combination of two or more.

The alkyl acrylate used in the crosslinked elastic body has an alkyl group having 1 to 8 carbon atoms, and may be linear or branched. For example, methyl acrylate, ethyl acrylate, butyl acrylate, propyl acrylate, octyl acrylate, etc. may be used alone or in combination of two or more. n-butyl and acrylic acid 2-
A monomer having a low glass transition temperature such as ethylhexyl is preferable.

The crosslinkable monomer copolymerized with the acrylic acid alkyl ester is a monomer containing two or more copolymerizable carbon double bonds in one molecule. Examples thereof include divinylbenzene, diallyl phthalate, mono- or polyethylene glycol dimethacrylate, allyl methacrylate, triallyl cyanurate, etc. These may be used alone or in combination of two or more. The acrylic resin can be produced by a known method such as bulk polymerization, suspension polymerization and emulsion polymerization.

The heat ray reflective particles used in the present invention include:
Synthetic mica or natural mica coated with titanium oxide is preferable, and the coating amount of titanium oxide is usually 30 to 60.
%, Preferably 40-50% by weight. If the coating amount of titanium oxide is outside the above range, a sufficient heat ray reflection effect cannot be obtained. The average particle diameter of the heat ray reflective particles is appropriately selected according to the thickness of the sheet, but if the particle diameter is too small, a sufficient heat ray reflection effect cannot be obtained, and conversely if the particle diameter is too large, the surface condition of the sheet deteriorates or the sheet There is a phenomenon of perforation. Usually, it is preferably about 1 to 60 μm, and particularly preferably about 1 to 20 μm when the sheet has a thickness of about 10 to 300 μm and is a thin film.

The content of the heat ray-reflecting particles depends on the desired heat ray-reflecting effect, the surface condition of the sheet, the thickness of the sheet, and the like, and it is difficult to specify the content in general.
In the case of about 0 μm, it is preferably 0.5 to 30 parts by weight, more preferably 5 to 20 parts by weight, based on 100 parts by weight of the acrylic resin containing the crosslinked elastic body. If the content is less than 0.5 parts by weight, a sufficient heat ray reflection effect cannot be obtained,
On the other hand, when it exceeds 30 parts by weight, elongation and toughness are lost, and it is difficult to obtain a product having a thickness of 10 to 300 μm, and the cost becomes high.

The heat ray-reflecting sheet comprising the acrylic resin of the present invention containing heat ray-reflecting particles is uniformly mixed by a known mixing means such as a high speed mixer, and the obtained mixture is pelletized and extruded. A sheet can be formed by a method (T-die method / inflation method), a calendar method, a solution casting method, or the like.

The thickness of the heat ray reflective sheet of the present invention is not particularly limited, but is usually in the range of about 5 mm to 10 μm. The one with a large thickness is used alone as a corrugated sheet. As for the one with a small thickness, not only as a single body but also as polycarbonate, PMMA, soft / hard PVC, ABS,
It is used by laminating it on polyolefin, polyester, etc. In this case, a suitable thickness is about 10 to 300 μm. A molded product obtained by laminating a heat ray reflection sheet of 10 to 300 μm on the above resin has a large solar radiation reflectance and a small solar radiation absorptivity. There is little temperature difference on the non-stick surface, and there is little warpage or distortion in the molded product.

Further, in the heat ray reflective sheet of the present invention, in addition to the above components, an ultraviolet absorber, an antioxidant, and
Lubricants, flame retardants, antistatic agents and the like can be blended in one kind or two or more kinds.

[0017]

The present invention will be described in more detail with reference to the following examples, but the present invention is not limited thereto.
The solar reflectance, the solar transmittance, the solar absorptance, and the total light transmittance were evaluated by the following methods. (1) Solar reflectance, solar transmittance, solar absorptance In accordance with JIS R3106, Shimadzu UV31
00PC type self-recording spectrophotometer, 340 with integrating sphere
The measurement was performed between ˜1800 nm. (2) Total light transmittance Based on ASTM D-1003, it measured using the turbidimeter NDH-1001DP by Nippon Denshoku Industries Co., Ltd.

Examples 1 to 3 By a conventional emulsion polymerization method, a crosslinked elastic body component consisting of 100 parts by weight of butyl acrylate and 1 part by weight of allyl methacrylate as a crosslinkable monomer was polymerized, and methyl methacrylate was present in the presence thereof. Acrylic resin component monomers consisting of 90 parts by weight and 10 parts by weight of butyl acrylate were continuously added and copolymerized. Crosslinked elastic body component is 30
It was set to% by weight. Then, the resin used in the present invention was obtained by coagulating, washing with water and drying by a conventional method.

The resulting crosslinked elastic body-containing acrylic resin 10
0 parts by weight of titanium oxide coated mica "Iriodin 2
11 "(particle size 5 to 20 μm, manufactured by Merck Japan Co., Ltd.) in an amount described in Table 1, and 2 parts by weight of an ultraviolet absorber" Tinuvin P "(manufactured by Ciba-Geigy) was added.
After blending with a Henschel mixer, pellets were made with a 40 mm extruder pelletizer. A sheet is formed by using the pellets by a T-die forming method.
A sheet of μm was obtained. For each sheet, the solar reflectance, the solar transmittance, the solar absorptance, and the total light transmittance were measured. The results are shown in Table 1. As shown in Table 1, Example 1
The sheets obtained in Nos. 3 to 3 show excellent solar reflectance, and the appearance of the sheets obtained is that the reflected light has a reddish color and the transmitted light has a greenish pearly luster and is excellent in design. there were.

[0020]

[Table 1]

Examples 4 to 6 The same evaluations were carried out for the resins and formulations shown in Example 1 except that the sheet thickness was changed. Table 2 shows the results.

[0022]

[Table 2]

Comparative Example 1 By the same emulsion polymerization method as in Example 1, 90 parts by weight of methyl methacrylate and 10 parts by weight of butyl acrylate were copolymerized while continuously adding an acrylic resin component monomer. . Then, the resin was solidified, washed with water and dried by a conventional method to obtain a resin containing no crosslinked elastic body. Example 1 was applied to the obtained resin.
Titanium oxide coated mica "Iriodin 21
1 "was added in an amount of 5 parts by weight, and after pellet formation, the sheet was formed by the T-die method to obtain a sheet of 150 μm. Since the obtained sheet did not contain a crosslinked elastic body, the sheet had neither elongation nor toughness and could not be used practically.

[0024]

As described above, according to the present invention, a sheet that is inexpensive and has excellent impact resistance and heat ray reflection performance is provided.

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Michio Matsuura 4-1-1 Koraibashi, Chuo-ku, Osaka City, Osaka Prefecture Nihon Shatai Co., Ltd. (72) Inventor Ken Morita 4-chome, Koraibashi, Chuo-ku, Osaka City, Osaka Prefecture No. 1 within Nippon Shokubai Co., Ltd.

Claims (7)

[Claims] 1. A heat ray reflective sheet comprising heat ray reflecting particles contained in an acrylic resin containing a crosslinked elastic body. 2. The crosslinked elastic body comprises an alkyl acrylate and at least one crosslinkable monomer selected from the group consisting of divinylbenzene, diallyl phthalate, mono- or polyethylene glycol dimethacrylate, allyl methacrylate and triallyl cyanurate. The heat ray reflective sheet according to claim 1, which is a copolymer with the body. 3. The heat ray reflective sheet according to claim 1, wherein the heat ray reflective particles are mica coated with titanium oxide. 4. The heat ray reflective sheet according to claim 1, wherein the thickness of the sheet is in the range of 10 to 300 μm. 5. A method for producing a heat ray reflective sheet, which comprises forming an acrylic resin composition containing heat ray reflective particles in an acrylic resin containing a crosslinked elastic body into a sheet. 6. The crosslinked elastic body comprises an alkyl acrylate and at least one crosslinkable monomer selected from the group consisting of divinylbenzene, diallyl phthalate, mono- or polyethylene glycol dimethacrylate, allyl methacrylate and triallyl cyanurate. The production method according to claim 5, which is a copolymer with a body. 7. The method according to claim 5, wherein the heat ray reflective particles are titanium oxide-coated mica.