HK1070861B - Color sheet having light-shielding effect - Google Patents

Description

Colored sheet with light shielding effect

Scope of the technology

The present invention relates to a colored sheet having a light shielding effect, which is suitable for use in roofs and exterior walls of buildings such as factories and houses, roofs and exterior walls of transportation vehicles such as containers and refrigerated vehicles, roofs and exterior walls of ships, machinery, warehouses, and livestock houses, and the like, and housings of camping tents and automobiles, and tent film materials, etc., and which can improve design and improve aesthetic appearance while preventing an increase in internal temperature due to sunlight irradiation.

Background

Roofs or exterior walls of buildings or structures are susceptible to failure when exposed to wind, rain and sunlight, and therefore, to prevent such failure and improve the aesthetic appearance, paint protection is often applied. In recent years, in order to improve the workability, a method has been started in which a colored film or sheet suitable for the application is formed in advance and disposed on a roof or an outer wall, thereby easily obtaining the same effect as that of coating using a paint. In particular, since buildings such as houses are often exposed to sunlight in summer, a film or sheet having an effect of suppressing a temperature rise inside the house is provided on a roof or an outer wall of the house to improve the habitability, and the amount of electricity consumed by air conditioners and the like used for temperature control is reduced, which is desirable not only from the viewpoint of global environment but also in close association with reduction in cooling cost.

In addition, in recent years, with the innovation of distribution, containers and refrigerated vehicles for transporting goods in a low temperature state have been widely used, but in order to effectively improve the refrigerating and cooling effects of containers and vehicles, it has been desired to arrange a film or sheet having high heat shielding properties. Recently, such heat shielding properties have been demanded, and at the same time, improvement of aesthetic appearance by imparting various colors to buildings, vehicles, facilities, and the like has been demanded.

However, a technique for providing a heat-shielding film or sheet has been already carried out, and for example, a sheet having heat shielding properties by containing a specific amount of an aluminum compound or a diimmonium type compound in a plastic resin (patent document 1), a heat-shielding color film formed by providing a layer containing metal-doped inorganic oxide fine particles on one surface of a thermoplastic resin film and further providing an outdoor stretching film containing hydrophilic inorganic colloidal particles to improve heat shielding properties (patent document 2), and a heat-shielding color film formed by mixing 2 or more kinds of pigments to impart heat-shielding properties to a thermoplastic resin film (patent document 3) are known.

[ patent document 1 ] Japanese patent application laid-open No. 8-81567 (claims)

[ patent document 2 ] Japanese patent laid-open No. Hei 10-250002 (claims)

[ patent document 3 ] Japanese patent laid-open No. 2002-12679 (claims)

However, the sheets and films described in patent documents 1 and 2 have translucency and are suitable for being stuck to window glass, but have problems that heat shielding performance is not so high and free color cannot be imparted.

Further, the sheet described in patent document 3 can impart a free color, but since it is a single layer, the selection range of the pigment is limited in order to achieve both color and heat shielding performance, and there arises a problem that an expensive pigment must be used. In addition, the thermoplastic resin is usually formed by rolling with a calender roll or by extrusion, but when glass beads are added, there are problems such as breakage of the glass beads, etc., lowering the heat shielding effect, and scratching of the rolls of the forming machine, etc. In addition, in a method of molding a film or sheet produced by rolling or extrusion molding, orientation occurs in the film or sheet in the machine direction, and curling tends to occur in the film or sheet due to heat or the like at the time of use, making it difficult to secure a light-shielding effect.

On the other hand, a light-shielding sheet is also known which has at least a base cloth, a light-shielding layer and a surface layer, the light-shielding layer being laminated on the base cloth and formed of a substance obtained by pasting aluminum powder and a polymer composition containing a black colorant, and the surface layer being laminated on the light-shielding layer and formed of a polymer composition (patent document 4). This light-shielding sheet is thinner than conventional light-shielding layers, but exhibits light-shielding properties exceeding those of the conventional light-shielding layers, and further, since the amount of the black colorant to be added can be suppressed, the light-shielding layer is not excessively black, and the influence on the surface layer color is reduced. However, since the use of the black-based coloring agent significantly suppresses the color development of each color, there is a need for improvement in order to realize the formation of a plurality of colors.

[ patent document 4 ] Japanese patent No. 3091685 (claims)

In addition, in the method of applying a coating material having a heat shielding effect, the coating material itself having a function of shielding heat is expensive as compared with a general coating material, and it is not preferable in terms of economy, and a method of reducing the cost is desired. Further, when a coating material having a heat shielding effect is applied, it is necessary to repeatedly apply the coating material a plurality of times in order to coat the coating material thickly, and the operation is very troublesome.

However, the tent is used in the field as an evacuation place or rescue facility at the time of disaster, and is used for training or actual activities of fire brigades and the like. However, on a day with a good weather, the temperature in the tent rises, and there is a problem that work in the tent is hindered, and a large-sized air conditioner is installed as a countermeasure, but in a particularly large-sized tent, the temperature in the tent is not easily lowered, and therefore, a lot of time and effort are required for temperature adjustment.

Disclosure of Invention

In view of the above-described situation, the present invention has been made to solve the various problems of the heat-shielding films proposed so far, and an object of the present invention is to provide a heat-shielding sheet having excellent heat shielding properties and solving the various disadvantages which have been considered as problems so far. Further, it is an object to provide a colored sheet having a light shielding effect which can be used as a film material for a tent having excellent heat shielding properties, particularly in order to reduce a temperature rise in the tent due to sunlight.

The invention relates to a colored sheet having a light shielding effect, which is characterized in that: the sheet comprises at least a reflective layer and a colored layer, wherein the colored layer is laminated on the side of the reflective layer exposed to light, the reflective layer has a solar reflectance of more than 60% in a wavelength range of 780-1350 nm, the colored layer has a light transmittance of more than 30% in the wavelength range of 780-1350 nm, and the colored layer has a solar absorptance of 10-80% in the wavelength range of 380-780 nm.

The reflective layer is preferably made of polyvinyl chloride resin containing at least one selected from glass beads, hollow glass spheres and microcapsules, titanium oxide white pigment and plasticizer, and has a thickness of 0.1 to 1 mm.

The colored layer contains at least one selected from the group consisting of polyvinyl chloride resin, acrylic resin, and polyurethane resin, has a thickness of 0.1 to 0.5mm, and has a solar absorptance of 40 to 80% in a wavelength range of 380 to 780 nm.

The reflective layer is preferably formed into a sheet shape by applying a plastisol containing a polyvinyl chloride resin as a main component to a substrate and heating and curing the plastisol.

The present invention also relates to a method for producing a colored sheet having a light shielding effect according to claim 1, wherein: a reflective layer is formed by applying a plastisol containing a polyvinyl chloride resin as a main component on a substrate, heating and curing the plastisol to form a colored layer, applying a composition containing a polyvinyl chloride resin as a main component, which contains at least one selected from glass beads, hollow glass spheres and microcapsules, a titanium oxide white pigment and a plasticizer, on the colored layer, and heating and curing the composition.

ADVANTAGEOUS EFFECTS OF INVENTION

According to the present invention, a colored sheet having a high light shielding effect and capable of imparting a free color can be provided by having a structure in which a reflective layer having a solar reflectance of 60% or more in a wavelength range of 780 to 1350nm and a colored layer having a light transmittance of 30% or more in a wavelength range of 780 to 1350nm and a solar absorptance of 10 to 80% in a wavelength range of 380 to 780nm are laminated.

Best mode for carrying out the invention

The present invention provides a coloring sheet having heat shielding property due to light shielding effect, characterized in that: the color filter is a laminated structure of a reflective layer for irregularly reflecting light and a colored layer capable of freely coloring. Therefore, the colored sheet of the present invention is configured by laminating a colored layer on the side of the reflective layer exposed to light. In other words, the colored sheet of the present invention has a colored layer and a reflective layer laminated in this order from the side exposed to light.

In the composition constituting the sheet of the present invention, a polyvinyl chloride resin, particularly an emulsion-polymerized polyvinyl chloride resin is preferably used for the reflective layer. As the polyvinyl chloride resin, a homopolymer of a polyvinyl chloride monomer, or a copolymer of a polyvinyl chloride monomer and a monomer copolymerizable with a polyvinyl chloride monomer such as a vinyl acetate monomer or an acrylonitrile monomer can be used. The polymerization method of these polyvinyl chloride resins is not particularly limited, and particularly, emulsion polymerization (emulsion polymerization) in a state of a plastisol which is paste when a plasticizer is blended is preferably used, and further, microsuspension polymerization, soap-free emulsion polymerization, suspension polymerization (suspension polymerization), or the like may be used.

A filler and a pigment for making the reflectance of light in a wavelength range of 780 to 1350nm to be 60% or more are blended in a reflection layer mainly composed of a polyvinyl chloride resin, but the most desirable configuration is to blend (1) at least one selected from the group consisting of glass beads, hollow glass spheres and microcapsules, and (2) a titanium oxide white pigment and (3) a plasticizer as essential components.

As the one or more substances selected from the group consisting of glass beads, hollow glass spheres and microcapsules, those having a particle diameter of about 1 to 150 μm, preferably about 5 to 100 μm, more preferably about 8 to 80 μm, can be used.

If the particle size exceeds 150. mu.m, workability upon preparation of the composition or upon molding into a sheet is deteriorated, while if the particle size is less than 1 μm, it is difficult to obtain a desired heat shielding effect by the addition of the filler. The amount of the polyvinyl chloride resin is preferably 5 to 20 parts by weight, more preferably 10 to 15 parts by weight, based on 100 parts by weight of the polyvinyl chloride resin. If the amount is less than 5 parts by weight, a sufficient heat shielding effect cannot be obtained, while if it exceeds 20 parts by weight, it tends to be difficult to form into a sheet. In the case of glass beads or hollow glass spheres, the glass composition, specific gravity (hollow ratio), and the like are not particularly limited, and various coupling treatments and the like may be optionally performed in order to improve the close bonding with the resin component. In the case of microcapsules, the composition of the shell is not particularly limited, and hollow-type microcapsules which expand by heating or both can be used, and bead-type microcapsules can also be used.

As the titanium oxide-based white pigment, either rutile type or anatase type can be used, but rutile type is more preferably used. The amount of the white pigment added is about 3 to 30 parts by weight, more preferably 10 to 20 parts by weight, per 100 parts by weight of the polyvinyl chloride resin. If the amount is less than 3 parts by weight, the heat shielding effect may be weak, while if it exceeds 30 parts by weight, the heat shielding effect is not so large, which may cause a problem in sheet formability. The titanium oxide white pigment may be optionally blended in a toner state in which the pigment is dispersed in a plasticizer or the like in advance.

As the plasticizer, a compound generally used for polyvinyl chloride resin can be used, and specifically, plasticizers such as phthalate esters represented by di (2-ethylhexyl) phthalate (DEHP), diisononyl phthalate (DINP), diisodecyl phthalate (DIDP), dibutyl phthalate (DBP), diundecyl phthalate (DUP), butylbenzyl phthalate (BBP), trimellitate esters represented by trioctyl trimellitate (TOTM), fatty acid esters represented by dioctyl adipate (DOA), dioctyl sebacate (DOS), and dioctyl azelate (DOZ), and polyethylene glycol adipate represented by polypropylene glycol can be used.

The amount of the plasticizer to be added is not particularly limited, and is 25 to 150 parts by weight, preferably 60 to 100 parts by weight, based on 100 parts by weight of the polyvinyl chloride resin. If the amount of the plasticizer is too small, the viscosity of the plastisol becomes high, and the coating becomes difficult, and when a sheet is obtained, it becomes difficult to obtain a sheet having good uniformity. On the other hand, if the plasticizer is too much, the sheet itself becomes too soft, and softens during use, and the heat resistance may deteriorate.

In addition, in the reflective layer compound composition, preferably according to the need to add commonly used polyvinyl chloride stabilizer, specifically, can be used in a wide range of Ba-Zn series, Ca-Zn series, zinc oxide series metal stabilizer. Further, an ultraviolet absorber such as a hindered amine compound, a benzotriazole compound, or a benzothiazole compound, an antioxidant, and various additives such as a viscosity reducer and a thickener may be optionally added to improve processability.

The blending composition for the reflective layer can be mixed by measuring each component and then uniformly mixing the components with a mixing stirrer such as a rotary disk stirrer. Further, if necessary, filtration for the purpose of removing the undispersed matter and vacuum defoaming for the purpose of removing bubbles may be carried out as desired, and favorable results may be obtained.

The colored layer may be formed of a resin layer made of any one of a polyvinyl chloride resin, an acrylic resin, and a polyurethane resin. When a polyvinyl chloride resin is used, a paste plastisol made of an emulsion polymerization type polyvinyl chloride resin substantially the same as the reflective layer is preferably used. In the present invention, the colored layer is characterized in that: by transmitting the light reflected by the reflective layer, heat generation due to light absorption is avoided, and coloring is imparted to the layer in accordance with the purpose of use. To achieve this object, various pigments and dyes may be added, and specific examples thereof include white lead, yellow lead, ultramarine blue, and titanium yellow.

When an acrylic resin is used, a solution polymer or an emulsion polymer of an acrylic acid ester or a methacrylic acid ester can be preferably used, and a colored resin layer can be formed by adding a desired colorant to these resin compositions.

Similarly, a colored resin layer can be formed by adding a colorant to a solution polymer or an emulsion polymer of a polyurethane resin.

As a method of molding the reflective layer and the colored layer, various methods can be selected, and the reflective layer may be first molded into a sheet shape and the colored layer may be laminated on one surface thereof, or conversely, the colored layer may be first formed and then the reflective layer may be laminated on one surface thereof. In particular, when a polyvinyl chloride resin paste plastisol is used for both the color layer and the reflective layer, a sheet layer can be formed by applying the color layer to a releasable paper or film by an appropriate method to a predetermined thickness, heating and curing the resultant, applying the reflective layer (or the color layer) to a predetermined thickness by an appropriate method, heating and curing the resultant, and then peeling the resultant from the releasable paper or film.

The method is particularly advantageous in that it does not destroy hollow glass spheres, microcapsules, etc. during molding.

When an acrylic resin or a urethane resin is used for the colored layer, only the reflective layer may be applied to a releasable paper or film, cured by heating and peeled off to form a reflective layer sheet, and then the colored layer may be laminated by a gravure coater or the like in a separate step.

By laminating a sheet having a structure of a colored layer and a reflective layer by these methods, heat shielding performance is achieved, and in order to impart beautiful color, it is necessary to: the reflective layer has a high solar reflectance in a wavelength range contributing to heat generation in the wavelength range constituting sunlight, the colored layer has a high solar transmittance in a wavelength range contributing to heat generation in the wavelength range constituting sunlight, and the colored layer has an appropriate solar absorptance in a wavelength range contributing to heat generation in the wavelength range constituting sunlight. That is, in the sheet configured to satisfy such conditions, the heat shielding property is ensured by controlling the reflectance with the reflective layer while the selected color has little influence on the heat shielding property, and a desired color can be imparted by the colored layer. In the present invention, the solar reflectance of the reflective layer is 60% or more, preferably 70% or more, and more preferably 80% or more in the wavelength range of 780 to 1350 nm. The wavelength range contributing to heat generation is mainly a range of 780nm or more in the wavelength range included in sunlight. In addition, the proportion of light having a wavelength of 1350nm or more is very small in the composition ratio of different wavelengths of sunlight. Therefore, the reflectance in the wavelength range of 780 to 1350nm becomes important not to absorb light but to prevent the heat accumulation in the reflective layer of the sheet by reflection. Therefore, if the reflectance is less than 60%, the effect is reduced.

The solar transmittance of the colored layer of the sheet of the present invention is 30% or more, preferably 40% or more, and more preferably 50% or more in the wavelength range of 780 to 1350 nm. If the solar transmittance is less than 30%, the colored layer absorbs light before the incident light reaches the reflective layer, and the colored layer absorbs reflected light reflected by the reflective layer before the incident light reaches the outside of the colored layer, whereby the sheet of the present invention stores heat.

In addition, the solar absorptivity of the colored layer is 10-80% in the wavelength range of 380-780 nm. The wavelength range of 380 to 780nm corresponds to the visible light range, and since the solar absorptance is constant in this range, the sheet of the present invention can be colored in various colors, and further, it is preferable that the sheet is a high-quality sheet. When the solar radiation absorption rate is 10%, the sheet is white, and when the sheet is colored in a color other than white, the lower limit of the solar radiation absorption rate is 40%. Further, sunlight in the wavelength range of 380 to 780nm has a small effect on heat generation, and even if sunlight in this wavelength range is absorbed, the sheet does not significantly store heat.

Therefore, it is necessary to determine the color and thickness (thickness and layer ratio of each layer) of the colored layer and the reflective layer within these ranges.

Further, the thickness of the reflective layer is preferably 0.1 to 1mm, more preferably 0.4 to 1mm, and when the thickness of the reflective layer is thinner than 0.1mm, it is difficult to secure a sufficient solar reflectance.

On the other hand, the thickness of the colored layer is preferably 0.1 to 0.5mm, and if it exceeds 0.5mm, it is difficult to secure a solar transmittance of 30% or more, and heat is accumulated in the colored layer, which is not preferable because the heat reflection performance is inhibited.

In order to attach the sheet of the present invention to the surface of an object, an adhesive layer may be provided on the back surface of the reflective layer in advance, and a commonly used method may be applied as a method for forming the adhesive layer. The sheet can be adhered to an adherend using various adhesives at any time during application. Further, the layer in contact with the adherend may be made to have appropriate tackiness to impart self-adhesive properties, and in this case, a small amount of a tackifier such as rosin ester may be added to the composition to further improve the adhesion properties.

In addition, the colored sheet of the present invention may be provided with an antifouling layer on the surface of the colored layer. The antifouling layer can be formed by applying an antifouling paint composed of a solvent-based, aqueous, or ultraviolet-curable paint.

Among them, as the solvent-based coating material, for example, acrylic resin-based, vinyl chloride resin-based, cellulose resin-based, fluorine resin-based, polyamide resin-based, polyurethane resin-based, epoxy resin-based, silicone resin-based coating materials can be used.

Examples of the water-based paint include acrylic resin-based, polyester resin-based, polyurethane resin-based, and epoxy resin-based paints.

Examples of the ultraviolet-curable coating material include acrylic resin-based, acrylic-modified urethane resin-based, acrylic-modified epoxy resin-based, mercapto derivative-based, and epoxy resin-based coating materials.

In addition, the colored sheet of the present invention may be provided with fibrous substrates such as woven fabric and nonwoven fabric on both sides of the reflective layer. The fibrous substrate may be laminated on the reflective layer side of the laminate of the reflective layer and the colored layer formed on the release paper with an adhesive, or the fibrous substrate may be laminated by forming the reflective layer on the fibrous substrate, impregnating the fibrous substrate with a resin forming the reflective layer, or the like. Further, a resin layer may be further provided on the back surface (fibrous base layer side) of the fibrous base layer of the laminate of the colored layer, the reflective layer, and the fibrous base layer to form a multilayer structure.

As described above, by providing the fibrous base material, the tear strength and tensile strength of the sheet itself are improved, and the durability in use and the dimensional stability in application are improved.

The sheet of the present invention is particularly suitable for sheet applications such as tarpaulins for tents. Since the tent is used in the field, there is a problem that the temperature in the tent is raised by the solar radiation on a day with a good weather, which hinders the work in the tent and the like. The problem associated with this temperature rise has been dealt with by providing an air conditioner or the like, but in a particularly large tent, the temperature inside the tent is not easily lowered, and a lot of effort is required for adjusting the temperature. However, the sheet of the present invention has excellent solar reflectance in a wavelength range where heat generation occurs, and therefore has a high light shielding effect, and can suppress a temperature rise in a tent due to solar radiation. In addition, since the solar radiation absorbing rate is constant in the wavelength range in which heat generation occurs, the color formation is good, and a tent with rich colors can be provided. The sheet of the present invention is processed into a multilayer structure having the above fiber base layer, and thus becomes a tent film material having high strength. The tarpaulin is suitable for tent material. To produce a tarpaulin, two sheets based on polyvinyl chloride are simultaneously heat laminated to a woven fabric, with the woven fabric being the middle layer. The two sheets may also be laminated using a chemical adhesive. At least one layer of the waterproof cloth thus obtained is composed of the colored sheet having a light-shielding effect according to the present invention when exposed to sunlight.

The present invention will be described in further detail with reference to examples, but the present invention is not limited to these examples.

Examples 1 to 9 and comparative examples 1 to 3

Preparation of paste plastisol for reflective layer and coloring layer

For forming the reflective layer: various fillers, white pigments, plasticizers (diisononyl phthalate) and heat stabilizers were uniformly mixed with emulsion-polymerized polyvinyl chloride (PX-QHPN: New first salt ビ Co.) by means of a rotary disk mixer to prepare a paste plastisol for a reflective layer.

Further, for molding the colored layer: a plasticizer (diisononyl phthalate), a heat stabilizer and a pigment were uniformly mixed with an emulsion-polymerized polyvinyl chloride (PSH-23, manufactured by Kaneka chemical Co., Ltd.) by a rotary disk mixer to prepare a paste plastisol for a coloring layer. The formulation of the paste-like plastisol for the reflective layer is shown in table 1, and the formulation of the paste-like plastisol for the colored layer is shown in tables 2 to 3.

TABLE 1

Reflecting layer (plastisol)	A1	A2	A3	A4	A5
						Prescription (parts by weight)
Polyvinyl chloride resin 1	100	100	100	100	100
						Plasticizer	70	70	70	70	70
Stabilizer 1	3	3	3	3	3
						Filler 1	15	15
Filler 2			15	15
						Pigment 1	15	15	15	15
Pigment 2					1
						Color phase	White colour (Bai)	White colour (Bai)	Ivory color	Ivory color	Green
Thickness (mm)	0.4	0.3	0.4	0.05	0.5
						Solar reflectance (%) of 780 to 1350nm	83	76	63	54	42

TABLE 2

Coloured layer (plastisol)	B1	B2	B3	B4	B5	B6
							Prescription (parts by weight)
Polyvinyl chloride resin 2	100	100	100	100	100	100
							Plasticizer	70	70	70	70	70	70
Stabilizer 1	3	3	3	3	3	3
							Pigment 2	1
Pigment 3		1		1	1	1
							Pigment 4			1
Pigment 5			0.1
							Color phase	Green	Yellow colour	Tea	Yellow colour	Yellow colour	Yellow colour
Thickness (mm)	0.1	0.1	0.1	0.2	0.4	0.6
							(ii) solar transmittance at 780-1350 nm (%)	46	47	49	42	35	28
(iv) a solar transmittance of 380 to 780nm (%)	56	45	60	49	54	58

TABLE 3

Coloured layer (plastisol)	B7	B8
			Prescription (parts by weight)
Acrylic resin	100
			Polyurethane resin		100
Plasticizer
			Stabilizer 2	1	1
Pigment 2	1
			Pigment 3		1
Pigment 4
			Pigment 5
Color phase	Green	Yellow colour
			Thickness (mm)	0.1	0.1
(ii) solar transmittance at 780-1350 nm (%)	45	47
			(iv) a solar transmittance of 380 to 780nm (%)	56	45

Polyvinyl chloride resin 1: "PX-QHPN" manufactured by NOVEL FIRST SALT ビ "

Polyvinyl chloride resin 2: "PSH-23" manufactured by Schouin chemical industries, Ltd "

Acrylic resin: manufactured by Imperial chemical industries "テイサンレジン WS-023B"

Polyurethane resin: water-based polyurethane resin, "アデカボンタイタ -HUX-290X", manufactured by Asahi Denka Kogyo Co., Ltd "

Plasticizer: diisononyl phthalate, manufactured by hydrophylic chemical industries

Stabilizer 1: "AC 183" manufactured by Asahi Denka "

Stabilizer 2: special chemical products of Qianye, キマソ - プ 944LD "

Filler 1: hollow glass beads, manufactured by Asahi glass Co., Ltd. "セルスタ -Z27"

Filler 2: ceramic balls, E-SPHERES manufactured by Pacific Cement Co., Ltd "

Pigment 1: titanium oxide pigment manufactured by テイカ Co., Ltd. "JR 600A"

Pigment 2: KT-1800, manufactured by Green pigment, Special colors industries Co., Ltd "

Pigment 3: FT-3001 manufactured by Fuji color industries Ltd "

Pigment 4: KT-3974 manufactured by Kabushiki Kaisha "

Pigment 5: k-213 manufactured by Dai Nippon ink chemical industry Co., Ltd "

Shaping of sheet material

First, in order to evaluate the performance of each of the reflective layer and the colored layer, the prepared paste plastisol was coated on a release paper with a predetermined thickness by a doctor blade method, heated at 140 ℃ for 2 minutes, and then heated at 195 ℃ for 3 minutes. The release paper was then cooled and peeled off to prepare a sheet. When a polyvinyl chloride resin is used for the colored layer as well as the reflective layer, a paste plastisol is first applied to a release paper to a predetermined thickness, heated at 140 ℃ for 2 minutes, coated with a substance for the colored layer, and heated at 195 ℃ for 3 minutes. Thereafter, the release paper was cooled and peeled off to prepare a composite sheet. The thickness of the reflective layer sheet is shown in Table 1, and the thickness of the colored layer sheet is shown in tables 2 to 3. The solar reflectance of each sheet is shown in table 1, and the solar transmittance and solar absorptance of each sheet are shown in tables 2 to 3.

Solar transmittance: the spectral transmittances of examples and comparative examples described later were measured in a predetermined wavelength range using a self-recording spectrophotometer U-4000 (manufactured by hitachi) with the transmittance of 100% in a state where no sample was placed, and the spectral transmittances were derived using JIS (japanese industrial standards) a5759 and table 3 attached thereto. The specific formula for calculating the solar transmittance is shown below.

Solar transmittance (T) at wavelength λ_λ) Light transmittance (t λ) of wavelength λ x weight coefficient (α)

Solar transmittance (T) ═ T350+ T400+. + T2100

Solar absorption rate: the absorptance + reflectance + transmittance was determined from the solar transmittance and the solar reflectance as 100.

Solar reflectance (divided solar reflectance test method): the solar reflectance of examples and comparative examples described below was measured in a predetermined wavelength range using a self-recording spectrophotometer U-4000 (manufactured by hitachi corporation) with the reflectance of an alumina white substrate set to 100%, and the sum of the values of the spectral reflectance multiplied by the weighting coefficients at the respective wavelengths was calculated using JIS (japanese industrial standard) a5759 with table 3 attached thereto, to derive the solar reflectance.

Heat insulating Performance test

The heat shielding performance test method used in the following examples was carried out by the following method. A steel plate having a width of 220mm, a length of 310mm and a thickness of 0.3mm, to which the heat shielding sheets obtained in examples and comparative examples were attached on the side of the reflection layer provided on the upper surface of a box having a height of 150mm, a width of 220mm and a length of 310mm and an area of the upper surface surrounded by the above was made of expanded polystyrene having a thickness of 30mm, and the expanded polystyrene was brought into contact with the steel plate side, and the temperature of the back surface of the sample and the inside of the box after an incandescent lamp was irradiated for 40 minutes and 200W from a height of 300mm above the sample (heat shielding sheet) was measured.

The sheet compositions of the examples and comparative examples, and the results of measuring the temperatures of the back surface and the inside of the case of the sample by the heat shield performance test method are shown in table 4.

Examples 1 to 9 are colored sheets having a heat shielding effect within the scope of the present invention, and the reflective layer and the colored layer are composite sheets of sheets having compositions and thicknesses shown in tables 1 to 3, and are prepared by the method described in "molding of sheet". Comparative examples 1 to 3 are also composite sheets having the compositions and thicknesses shown in tables 1 and 2, and the reflectance or transmittance was out of the range of the present invention. Among them, comparative example 3 is a sheet having a composition of A1 and a thickness of 0.5 mm. From the results, it can be seen that the sheets within the scope of the present invention exhibit good heat-shielding properties.

TABLE 4

	Form a	Colour(s)	Thickness (mm)	Ratio of reflective layer (%)	Back temperature (. degree.C.)	In-box temperature (. degree. C.)
							Example 1	A1×B1	Green	0.5	80	43	31
Example 2	A2×B1	Green	0.4	75	46	34
							Example 3	A3×B1	Green	0.5	80	48	37
Example 4	A1×B2	Yellow colour	0.5	80	45	32
							Example 5	A1×B3	Tea	0.5	80	48	36
Example 6	A1×B4	Yellow colour	0.6	67	47	35
							Example 7	A1×B5	Yellow colour	0.8	50	49	38
Example 8	A1×B7	Green	0.5	80	43	31
							Example 9	A1×B8	Yellow colour	0.4	75	46	34
Comparative example 1	A4×B1	Green	0.2	50	61	45
							Comparative example 2	A1×B6	Yellow colour	1.0	40	60	45
Comparative example 3 (general sheet)	A5 (matching)	Green	0.5	-	68	49

Claims (5)

1. A colored sheet having a light shielding effect, which comprises at least a reflective layer and a colored layer, and which is formed by laminating the colored layer on the side of the reflective layer exposed to light, wherein the reflective layer contains a titanium oxide-based white pigment, exhibits a white or ivory hue, and has a solar reflectance of 60% or more in a wavelength range of 780 to 1350nm, and the colored layer has a solar transmittance of 30% or more in a wavelength range of 780 to 1350nm and a solar absorptance of 10 to 80% in a wavelength range of 380 to 780 nm;

the solar reflectance is the sum of the values of spectral reflectance multiplied by the weighting coefficients at the respective wavelengths using JIS a5759 and table 3,

the solar transmittance is the sum of the values obtained by multiplying the weight coefficient at each wavelength by the spectral transmittance according to JIS A5759 and Table 3,

the solar absorptance is a value obtained by subtracting the sum of solar transmittance and solar reflectance in the wavelength range from 100.

2. The colored sheet having a light-shielding effect according to claim 1, wherein the reflective layer is composed of a polyvinyl chloride resin containing at least one selected from glass beads and microcapsules and a plasticizer in addition to the titanium oxide white pigment, and has a thickness of 0.1 to 1 mm.

3. The colored sheet having a light-shielding effect according to claim 1 or 2, wherein the colored layer contains at least one selected from a polyvinyl chloride resin, an acrylic resin and a polyurethane resin, has a thickness of 0.1 to 0.5mm, and has a solar absorptance of 40 to 80% in a wavelength range of 380 to 780 nm.

4. The colored sheet having a light-shielding effect according to claim 1 or 2, wherein the reflective layer is formed in a sheet form by applying a plastisol containing a polyvinyl chloride resin as a main component on the substrate and curing the plastisol by heating.

5. The method for producing a colored sheet having a light shielding effect according to claim 1, comprising: a reflective layer is formed by applying a plastisol containing a polyvinyl chloride resin as a main component on a substrate, heating and curing the plastisol to form a colored layer, applying a composition containing a polyvinyl chloride resin as a main component, which contains at least one selected from glass beads and microcapsules, a titanium oxide white pigment, and a plasticizer, on the colored layer, and heating and curing the composition.