JP2014095272A - Transparent heat-ray reflecting roll screen - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a transparent roll screen excellent in heat-ray reflectivity.SOLUTION: A transparent heat-ray reflecting roll screen of the present invention includes: a transparent base film 12; a heat-ray reflecting layer 14 that is formed on an indoor-side surface of the base film 12; a protective layer 16 that is made of an ultraviolet curing resin with added metal oxide particles and superposed to protect the heat-ray reflecting layer 14; and an anti-blocking hard coat later 18 that is formed on an outdoor-side surface of the base film 12.

Description

  The present invention relates to a transparent heat ray reflective roll screen installed in a window of a house, a building, a vehicle, etc., and more specifically, it has a high visible light transmittance and excellent transparency, and also has a high solar radiation reflectance and an effect of shielding heat rays. The present invention relates to an excellent transparent heat ray reflective roll screen.

Conventionally, houses, buildings, vehicles, etc. have been provided with windows for viewing the outside scenery, lighting and ventilation, but the windows transmit not only visible sunlight but also near infrared light, Since far-infrared rays are once absorbed and re-radiated into the room, the heat insulation is poor, which has been a major factor in increasing the air conditioning load of buildings and vehicles.
In view of this, glass with an infrared shielding function having a function of transmitting visible light but reflecting or absorbing infrared light, and a heat ray reflective film used by being attached to a window have been proposed.

However, windows with infrared shielding glass or heat ray reflective films reflect solar heat rays throughout the year.
Although this has the effect of reducing the cooling load in the summer, the heating load increases by the amount that the heat of solar radiation cannot be used in the winter, and the energy saving effect throughout the year is not much different from the case where it is not constructed.

  Therefore, a technique for obtaining an energy saving effect by reflecting the heat rays of solar radiation as necessary by disposing the heat ray reflective film in a roll screen shape and installing it on a window is disclosed (for example, see Patent Document 1 below).

Japanese Patent Laid-Open No. 5-272279

  However, in the conventional roll screen, since the protective layer provided to protect the infrared reflective layer formed on the surface absorbs heat (heat rays), the roll screen itself absorbs the heat of solar radiation and indoors. There is a problem that re-radiation occurs and the cooling load reduction effect is small.

  Therefore, an object of the present invention is to provide a transparent roll screen excellent in heat ray reflectivity, which uses a protective layer having both high surface hardness and low emissivity for protecting the infrared reflective layer.

The present invention that solves the above-mentioned problems is a transparent heat ray reflective roll screen,
A transparent base film,
A heat ray reflective layer formed on one surface of the substrate film;
It is made of a thermosetting or ultraviolet curable resin containing 20 to 80% by weight of metal oxide particles, which is further laminated on one surface side of the heat ray reflective layer, and has a thickness of 0.5 to 10 μm. A protective layer;
An anti-blocking hard coat layer formed on the other surface of the base film.

  That is, the inventor of the present application should form a protective layer having a high hardness that can withstand sliding of the roll screen while keeping the emissivity on the surface side of one side (for example, the outdoor side) on which the heat ray reflective layer is formed. As a result of intensive studies, both the surface hardness that can withstand sliding and low emissivity are achieved by using a cured resin mixed with specific metal oxide fine particles as a protective layer to protect the surface of the heat ray reflective layer. It was found that it can be made.

According to the present invention, it is possible to provide a roll screen that is transparent and excellent in heat ray reflectivity and can withstand sliding of the roll screen.
According to the invention of claim 2 of the present application, the metal oxide fine particles are zinc oxide, magnesium oxide, calcium oxide, silicon oxide, manganese oxide fine particles, or a mixture thereof. In this case, the scratch resistance of the roll screen can be improved and the emissivity can be further suppressed.
Furthermore, according to the invention of claim 3 of the present application, the particle diameter of the metal oxide fine particles is at most 1000 nm, particularly in the range of 5 to 500 nm. In this case, the transmittance of visible light can be secured while suppressing the emissivity of the roll screen.

The figure which shows typically the structure of the transparent heat ray reflective roll screen of this invention. Schematic which shows the whole measuring apparatus used for experiment of thermal insulation temperature measurement.

  Hereinafter, an embodiment of the transparent heat ray reflective roll screen of the present invention will be described in detail with reference to FIG.

  As shown in FIG. 1, the transparent heat ray reflective roll screen 10 of the present embodiment includes a transparent base film 12, a heat ray reflective layer 14 formed on one surface of the base film 12, and the heat ray. In order to protect the reflective layer 14, the protective layer 16 made of a cured resin containing metal oxide particles and further laminated on the other surface of the base film 12 are laminated on one surface side. And a coat layer 18.

[Base film]
As the base film 12, a film that does not hinder transparency such as polyethylene terephthalate, polybutylene terephthalate, polyethylene naphthalate, polycarbonate, polypropylene, polyethylene, polyarylate, acrylic, acetylcellulose, polyvinyl chloride, and the like can be used. In particular, a biaxially stretched material is preferable because mechanical strength and dimensional stability are improved.
Although the thickness can be suitably selected with respect to the material applied, it is generally 25-500 micrometers, Preferably it is 50-200 micrometers.
In this base film 12, one surface on which a heat ray reflective layer 14 described later is laminated may be subjected to a surface treatment such as an easy adhesion treatment for the purpose of improving the adhesion with the heat ray reflective layer 14, Further, a surface treatment layer such as an easy adhesion layer may be provided separately.

[Heat ray reflective layer]
The heat ray reflective layer 14 transmits visible light and reflects infrared rays. The visible light transmittance of the heat ray reflective layer 14 alone is preferably 50% or more. Further, the vertical emissivity of the heat ray reflective layer 14 alone is preferably 0.2 or less.

The heat ray reflective layer 14 is usually a multilayer film formed by laminating a metal thin film and a high refractive index thin film.
Here, the material for forming the metal thin film is, for example, gold, silver, copper, or an alloy thereof.
The thickness of the metal thin film is preferably adjusted in the range of 5 nm to 100 nm so that both the visible light transmittance and the infrared reflectance are high.

The high-refractive-index thin film imparts transparency (transmittance of visible light) to the transparent heat ray reflective roll screen 10 as a whole by utilizing the interference effect. The material is titanium oxide, niobium oxide, indium oxide, or the like. A thing etc. or these combination is used.
The high refractive index thin film preferably has a refractive index in the range of 1.8 to 2.7. If this refractive index is outside the above numerical range, it is difficult to use a certain interference effect, or the film becomes too thick or too thin, resulting in poor productivity and flexibility.
The thickness of the high refractive index thin film is preferably adjusted in the range of 20 to 80 nm. When this thickness is outside the above numerical range, the transparency (transparency of visible light and color) of the transparent heat ray reflective roll screen 10 is deteriorated.

Both the metal thin film and the high refractive index thin film are formed, for example, by sputtering, vacuum deposition, plasma CVD, or the like.
That is, the heat ray reflective layer 14 can be adhered and laminated on the base film 12 by these methods. The side in contact with the base film 12 may be either a metal thin film or a high refractive index thin film.

[Protective layer]
On the upper layer of the heat ray reflective layer 14, a protective layer 16 made of a resin curable by heat, ultraviolet rays or the like is laminated as a surface protective layer for improving the scratch resistance.
The thickness of the protective layer 16 is preferably 0.5 to 10 μm, particularly 1 to 5 μm. When the thickness is 0.5 μm or more, sufficient scratch resistance for use as a roll screen is exhibited, and when the thickness is 10 μm or less, an emissivity of 0.4 that does not affect the indoor temperature can be achieved.

The protective layer 16 contains specific metal oxide fine particles in an amount of 20 wt% or more and less than 80 wt%. By containing the metal oxide fine particles, the scratch resistance can be improved and the emissivity can be further suppressed.
When the metal oxide fine particles are less than 20% by weight, the effect of improving the scratch resistance of the protective layer 16 is not sufficiently exhibited. On the other hand, if it is 80% by weight or more, the flexibility of the protective layer 16 is excessively lowered, and defects such as cracks occur when the transparent heat ray reflective roll screen 10 is rolled up and rolled.

Examples of the metal oxide fine particles include fine particles of zinc oxide, magnesium oxide, calcium oxide, silicon oxide or manganese oxide, and a mixture thereof.
The metal oxide fine particles preferably have a particle diameter in the range of 5 to 500 nm, with 1000 nm as the upper limit, in order to ensure visible light transmission. When the numerical value is 5 nm or more, the emissivity of the protective layer 16 is suppressed, and when the thickness is 10 μm or less, an emissivity of 0.4 or less can be achieved. And if it is less than 5 nm, it becomes difficult to disperse stably (homogeneously) in the heat ray reflective layer 14, and as a result, suppression of emissivity and scratch resistance deteriorate.
On the other hand, if it is 1000 nm or less, the transmittance | permeability of visible light can be ensured, and if it is 500 nm or less especially, since scattering of visible light can be reduced, it is more preferable.

  The curable resin used in the present embodiment is hardened by heat or ultraviolet rays and can be easily molded. Moreover, an ultraviolet curable resin is preferable from the viewpoint of handling properties and work efficiency after curing, and among them, those having a pencil hardness of at least 2H are preferable from the viewpoint of scratch resistance.

Examples of the ultraviolet curable resin described above are synthesized from a polyfunctional acrylate resin such as acrylic acid or methacrylic acid ester having a polyhydric alcohol, and acrylic acid or methacrylic acid having a diisocyanate and a polyhydric alcohol. Such polyfunctional urethane acrylate resins can be mentioned.
Furthermore, polyether resins having an acrylate functional group, polyester resins, epoxy resins, alkyd resins, spiroacetal resins, polybutadiene resins, polythiol polyene resins, and the like can also be suitably used.

  Reactive diluents for these resins include relatively low viscosity 1,6-hexanediol di (meth) acrylate, tripropylene glycol di (meth) acrylate, diethylene glycol di (meth) acrylate, hexanediol ( Bi- or higher functional monomers and oligomers such as (meth) acrylate, pentaerythritol tri (meth) acrylate, trimethylolpropane tri (metha) acrylate, dipentaerythritol hexa (meth) acrylate, neopentyl glycol di (meth) acrylate, and the like Acrylates such as N-vinylpyrrolidone, ethyl acrylate, propyl acrylate, ethyl methacrylate, propyl methacrylate, isopropyl methacrylate, butyl methacrylate, hexyl methacrylate Methacrylic acid esters such as acrylate, isooctyl methacrylate, 2-hydroxyethyl methacrylate, cyclohexyl methacrylate, and nonylphenyl methacrylate, tetrahydrofurfuryl methacrylate, and derivatives such as caprolactone modified products thereof, styrene, α-methylstyrene, acrylic acid, etc. A monofunctional monomer is mentioned, These are not restricted to 1 type, You may use 2 or more types together.

Furthermore, as photosensitizers (radical polymerization initiators) for these resins, benzoins such as benzoin, benzoin methyl ether, benzoin ethyl ether, benzoin isopropyl ether, and benzyl methyl ketal are used. The alkyl ethers; acetophenones such as acetophenone, 2,2-dimethoxy-2-phenylacetophenone, 1-hydroxycyclohexyl phenyl ketone; anthraquinones such as methyl anthraquinone, 2-ethylanthraquinone, 2-amylanthraquinone; thioxanthone, 2, Thioxanthones such as 4-diethylthioxanthone and 2,4-diisopropylthioxanthone; Ketals such as acetophenone dimethyl ketal and benzyldimethyl ketal; Benzophenone and 4,4-bismethylaminoben Benzophenones such as phenone and there are azo compounds. These can be used alone or as a mixture of two or more thereof, and further, tertiary amines such as triethanolamine and methyldiethanolamine; benzoic acid derivatives such as 2-dimethylaminoethylbenzoic acid and ethyl 4-dimethylaminobenzoate, etc. It can be used in combination with a photoinitiator aid or the like.
The amount of these organic peroxides and photopolymerization initiators used is 0.5 to 20 parts by weight, preferably 1 to 15 parts by weight, based on 100 parts by weight of the polymerizable component of the resin composition.

In addition, you may mix | blend a well-known general coating additive with respect to each curable resin mentioned above as needed.
For example, a silicon-based or fluorine-based additive that imparts leveling or surface slip properties is effective in preventing scratches on the surface of the protective layer 16, and is added when ultraviolet rays are used as active energy rays. Bleeding of the agent to the air interface can reduce the inhibition of resin curing by oxygen, and an effective degree of curing can be obtained even under low irradiation intensity conditions.
Appropriate amounts of these additives are 0.01 to 0.5 parts by weight per 100 parts by weight of the active energy ray-curable resin.

  The said protective layer 16 is laminated | stacked by apply | coating the coating liquid containing the said component by well-known methods, such as a bar coat method, a doctor blade method, a reverse roll coat method, and a gravure roll coat method.

[Anti-blocking hard coat layer]
In the transparent heat ray reflective roll screen 10 of this embodiment, an anti-blocking hard coat layer 18 is laminated on the other surface side of the base film 12.
Similar to the protective layer 16, the anti-blocking hard coat layer 18 is laminated by a known coating method such as a bar coating method, a doctor blade method, a reverse roll coating method, or a gravure roll coating method.

The anti-blocking hard coat layer 18 prevents scratches caused by sliding of the transparent heat ray reflective roll screen 10 due to winding, unwinding, etc., and the appearance is deteriorated, and the protective layer 16 is formed on one surface side. Therefore, curling of the screen 10 is suppressed.
Further, the thickness of the anti-blocking hard coat layer 18 is not particularly limited, but it is preferable to consider the curl strength of the protective layer 16 laminated on the opposite surface through the base film 12.

  Further, when the screen 10 is rolled up, it is blocked with the protective layer 16 (the protective layer 16 positioned on one surface of the rolled screen 10 and the anti-blocking hard coat positioned on the other surface). In order to prevent the layer 18 from adhering to the layer 18, it is difficult to remove the anti-blocking hard coat layer 18. preferable. That is, it is preferable that the surface state of the anti-blocking hard coat layer 18 on the side facing the protective layer 16 is uneven to reduce the adhesion between the coat layer 18 and the protective layer 16. Therefore, even if the resin beads are not used, if the surface state is uneven, the anti-blocking hard coat layer 18 of the present invention can be adopted.

The resin beads have excellent optical transparency such as acrylic resin beads, silicon resin beads, nylon resin beads, styrene resin beads, polyethylene resin beads, benzoguanamine resin beads, urethane resin beads, etc. The thing close | similar to the refractive index of the above-mentioned resin binder is preferable.
Specifically, it is desirable that the difference between the refractive index of the resin and the refractive index of the resin beads is within 0.2, preferably within 0.1, and more preferably within 0.05.
Thus, by making the refractive indexes of both close, the internal haze (optical haze) of the anti-blocking hard coat layer 18 (containing resin beads) can be reduced or eliminated, and high transparency can be maintained. it can.

The content of the resin beads in the antiblocking hard coat layer 18 is not particularly limited, but the lower limit is 0.01% by weight or more, preferably 0.02% by weight or more, and the upper limit is 1.5% by weight or less, preferably Is about 1.0% by weight or less.
By setting the content to 0.01% by weight or more, the blocking phenomenon can be efficiently prevented, and by setting the content to 1.5% by weight or less, the transparency of the roll screen 10 can be maintained.

Although the average particle diameter of the resin beads varies depending on the thickness of the anti-blocking hard coat layer 18, it cannot be generally stated, but the lower limit is 2 μm or more, more preferably 5 μm or more, and the upper limit is 30 μm or less, preferably 15 μm or less. Use one.
By setting the average particle size of the resin beads to 2 μm or more, the resin beads can be protruded from the surface of the anti-blocking hard coat layer 18 from the viewpoint of antiblocking properties. By setting the average particle size to 30 μm or less, the resin is removed from the resin layer. It is possible to prevent the beads from falling off.
Moreover, in order to make the protrusion part of a resin bead smaller than the thickness of the adhesive agent mentioned later, it is preferable that the average particle diameter of a resin bead shall be 30 micrometers or less.

As long as the anti-blocking hard coat layer 18 does not impair the function of the present invention, the lubricant, dye, fluorescent brightener, colorant, pigment, antistatic agent, flame retardant, antibacterial agent, antifungal agent Various additives such as ultraviolet absorbers, light stabilizers, antioxidants, plasticizers, leveling agents, flow regulators, antifoaming agents, and dispersing agents can be included.
In order to reduce the adhesion between the anti-blocking hard coat layer 18 and the protective layer 16, for example, the material of the anti-blocking hard coat layer 18 and the material of the protective layer 16 are each charged with the same charge (+ or − ) Charged may be used.

  As is clear from the above description, the present invention uses a cured resin having a predetermined thickness mixed with specific metal oxide fine particles as the protective layer 16 for protecting the surface of the heat ray reflective layer 14. It is possible to provide a roll screen excellent in transparency and heat ray reflectivity.

In addition, when the heat ray reflective layer 14 is laminated | stacked on the outdoor side of the base film 12 as described in the above-mentioned Example, since it reflects the solar radiation which enters the room from the outside, it is suitable for summer use.
Further, when the direction of the transparent heat ray reflective roll screen 10 is used in a form in which the heat ray reflective layer 14 is laminated on the indoor side of the base film 12, the solar radiation entering the room from the outside is not reflected, but is accumulated in the room. By reflecting heat (infrared rays), heat can be prevented from being radiated to the outside, so that it can be suitably used even in winter.

[Experimental example]
Hereinafter, for the transparent heat ray reflective roll screen according to the present invention, the material of the protective layer, its thickness, the amount of metal oxide fine particles contained in the protective layer and the particle size thereof, and required as a transparent heat ray reflective roll screen. 4. Physical properties (1. scratch resistance, 2. emissivity of (protective layer), 3. thermal insulation properties of (roll screen), 4. occurrence of defects (cracks) during roll), and 5. Describe the results for the overall evaluation.

In this experiment, the material and thickness of the protective layer shown in Table 1, the amount and particle size of the metal oxide fine particles contained in the protective layer, and each layer under the following conditions were used as a base film or the like. On the other hand, after producing transparent heat ray reflective roll screens according to Examples 1 to 12 and Comparative Examples 1 to 6, respectively, the above physical property values and the like were obtained as samples by cutting them into desired dimensions. .
As a reference example, a transparent heat ray reflective roll screen using only a 50 μm PET resin as a protective layer was prepared and cut into desired dimensions to obtain various physical property values of the sample.
・ Base film: Polyethylene terephthalate with a thickness of 50 μm ・ Heat ray reflection layer: Lamination by sputtering method Metal thin film: Silver copper (copper 11 wt%) alloy with a thickness of 20 nm High refractive index thin film: Titanium oxide with a thickness of 35 nm ・ Protective layer : Material and thickness as shown in Table 1, coated by bar coating method, and the amount and particle size of metal oxide fine particles are as shown in Table 1. Anti-blocking hard coat layer: 5 μm thick, with protective layer The same material, coated by the bar coating method and laminated. Resin beads: Same material as the protective layer, particle size 10μm, 0.5% by weight

The confirmation method of each above-mentioned physical property value is as follows.
・ Protective layer thickness:
As the thickness of the protective layer, an average value obtained by measuring the position of 5 points per sample with a micrometer was adopted. The thickness was determined by calculation from the difference between the thickness of the base film + protective layer and the thickness of the base film.
1. Scratch resistance:
Steel wool (# 0000) was used to reciprocate 100 times on each sample at a load of 1 kg / cm ² , and then the presence or absence of scratches on the sample was visually observed. In the case of almost no scratches, ◎, in the case of few scratches, ◯ when there is no problem in permeability, and × when there is a scratch.
2. Emissivity (of protective layer):
A contact thermometer is attached to each sample, and the surface temperature of each sample is measured. At the same time, a thermal image of the sample surface was measured with an emissivity thermometer (CPA-E40: manufactured by Chino Corporation), and the emissivity was set to be the same as the temperature indicated by the contact-type thermometer. The emissivity at this time was adopted as the emissivity of each sample.
3. Heat insulation property (temperature) of roll screen:
Using a test apparatus shown in FIG. 2 (a glass box having a thickness of 4 mm is installed in an opening of a heat insulation box (inner dimensions: 140 mm × 140 mm × 170 mm) provided with a heat source and a thermocouple to make a sealed state) Each sample was attached to the inside of the plate so that the protective layer was located on the heat source side, and the temperature in the heat insulation box was used to obtain the heat shielding characteristics.
4). Occurrence of defects (cracks) during rolling:
Each sample was wound up in a roll and visually observed for the presence or absence of cracks. And when it did not occur, it was marked as ◯, and when it occurred, it was marked as x.
5. Comprehensive evaluation:
The contents of the above 1 to 4 were combined, and “◎” was given to those particularly suitable as the transparent heat ray reflective roll screen of the present invention, “◯” to those suitable, and “x” to those not suitable.
In Table 1, symbols representing “material” of “protective layer” are “A”: acrylic ultraviolet curable resin, “B”: methacrylic ultraviolet curable resin, “C”: acrylic thermosetting resin, “ P ”: refers to PET resin.

  The results of the above 1 to 5 are also shown in Table 1. As a result, it was confirmed that the roll screen was transparent, excellent in heat ray reflectivity and capable of withstanding sliding during operation within the scope of the present invention described above. In particular, when the thickness of the protective layer was 5 μm or more, the scratch resistance was high.

  In addition, regarding the above-mentioned experiment, when each sample was wound up into a roll using an anti-blocking hard coat layer that did not contain resin beads and the surface state was flattened, blocking occurred, and as a roll screen It was confirmed that it cannot be used.

DESCRIPTION OF SYMBOLS 10 Roll screen 12 Base film 14 Heat ray reflective layer 16 Protective layer 18 Anti-blocking hard coat layer

Claims (3)

A transparent base film,
A heat ray reflective layer formed on one surface of the substrate film;
It is made of a thermosetting or ultraviolet curable resin containing 20 to 80% by weight of metal oxide particles, which is further laminated on one surface side of the heat ray reflective layer, and has a thickness of 0.5 to 10 μm. A protective layer;
A transparent heat ray reflective roll screen, comprising: an anti-blocking hard coat layer formed on the other surface of the substrate film.   The transparent heat ray reflective roll screen according to claim 1, wherein the metal oxide fine particles are zinc oxide, magnesium oxide, calcium oxide, silicon oxide, manganese oxide fine particles or a mixture thereof.   3. The transparent heat ray reflective roll screen according to claim 1, wherein the metal oxide fine particles have a maximum particle size of 1000 nm, particularly 5 to 500 nm.

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