JP2002006399A - Reflection screen and method for manufacturing the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a reflection screen capable of plotting and deletion by a marker, etc., with little halation on which an image with a clear wide viewing angle can be obtained, and a method for manufacturing the same. SOLUTION: The reflecting screen has a surface vitreous enamel layer containing titanium oxide coated particles and white glaze in an outside surface of a metallic substrate, preferably surface roughness: Ra is 2.5 μm or more, or Ra is 1.5 μm or more and less than 2.5 μm, and Glossiness: Gs (45 deg.) is 15-25%. In the method for manufacturing the reflecting screen, (1) vitreous enamel surface glaze containing powder composed of the titanium oxide coated particle, and the white glaze, or (2) the vitreous enamel surface glaze which contains at least two kinds of powder composed of the titanium oxide coated particle and having different average particle diameter, the white glaze and furthermore transparent glaze preferably, is applied on the outside surface of a cold rolled steel sheet or an aluminum metal plating steel sheet, and a Zn-Al alloy plating steel sheet, and is baked in 700-850 deg.C or 400-600 deg.C.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

[0001] 1. Field of the Invention [0002] The present invention relates to a reflection screen for projecting characters, images, images, and the like using a liquid crystal projector, a three-tube projector, an OHP, a slide, and the like, and a method of manufacturing the same.

[0002]

2. Description of the Related Art Conventionally, a reflection screen for projecting characters, images, images and the like has a reflection characteristic shown in FIG. In FIG. 4, 1 indicates incident light, 2 indicates reflected light, 3 indicates a reflection screen, and 4 indicates beads.

That is, the reflection characteristics of the reflection screen are as follows:
They are roughly classified into the following (1) to (3). (1): Diffuse reflection type (reflection close to perfect diffusion) [Fig. 4 (a)
(2): Retro-reflective type (reflection in the same direction as incident light) [Fig. 4 (b)
(3): Regular reflection type (specular reflection in the incident direction) [Fig. 4 (c)
The above-described reflective screen uses cloth, vinyl chloride, or the like as a base material, and has irregularities on its surface or beads 4 arranged to adjust the reflection angle, but has the following problems.

(1): Diffuse reflection type screen [FIG. 4 (a)]
Has a wide viewing angle, but has low reflection luminance at all viewing angles and lacks sharpness (resolution) of an image. (2): The retroreflective screen (FIG. 4 (b)) has a sharp image, but has a narrow viewing angle, tends to cause halation, and requires careful handling due to falling off beads.

(3): The reflection type screen (FIG. 4 (c))
Halation easily occurs. (4): Both types of reflective screens are made of cloth,
The use of vinyl chloride or the like has the following problems. Surface hardness is small and easily scratched. Since ink penetrates, drawing and erasing using markers such as whiteboard markers cannot be performed.

[0006] Wrinkles are liable to occur, and it is necessary to extend wrinkles by applying tension using a spring or the like at the time of construction at the time of manufacturing, which requires man-hours for construction.

[0007]

DISCLOSURE OF THE INVENTION The present invention solves the above-mentioned problems of the prior art, and provides a clear image with a wide viewing angle, little halation, and furthermore, writing and erasing with a marker or the like is not possible. It is an object of the present invention to provide a reflective screen that is possible, easy to handle, and excellent in workability, and a method for manufacturing the same.

[0008]

A first aspect of the present invention is a reflection screen having a surface enamel layer containing titanium oxide-coated particles and a white glaze on an outer surface of a metal substrate. In the first invention, the surface enamel layer has a surface roughness Ra (arithmetic mean roughness) of preferably 2.5 μm.
m or more, more preferably 2.5 μm or more and 10 μm or less, and more preferably 2.7 μm or more and 10 μm or less (a first preferred embodiment of the first invention).

In the first invention, the surface enamel layer has a surface roughness Ra (arithmetic mean roughness) of preferably 1.5 μm or more and less than 2.5 μm, more preferably 1.7 μm or less.
μm or more, 2.0 μm or less, more preferably 1.70 μm or more, 1.95 μm or less, most preferably 1.70 μm or more, 1.90 μm or less.
It is preferable that the particle diameter is not more than μm and the glossiness: Gs (45 °) is 15 to 25% (a second preferred embodiment of the first invention).

[0010] In the second preferred embodiment of the first invention, it is more preferable that the surface enamel layer further contains a transparent glaze (third preferred embodiment of the first invention). In the first invention and the first to third preferred embodiments of the first invention, the particle diameter of the titanium oxide-coated particles is preferably 100 μm or less, more preferably 80 μm or less.
μm or less (the fourth aspect of the first invention).
Preferred embodiment to seventh preferred embodiment).

In the first invention and the first to seventh preferred embodiments of the first invention, the titanium oxide-coated particles are particles having titanium oxide coated on the surface of mica particles. It is preferable (the eighth preferred embodiment to the fifteenth preferred embodiment of the first invention). In the eighth preferred embodiment to the fifteenth preferred embodiment of the first invention, the mica particles are preferably lamellar mica particles (the sixteenth preferred embodiment to the twenty-third preferred embodiment of the first invention). Preferred embodiment).

Further, in the first invention and the first to twenty-third preferred embodiments of the first invention, the content of the titanium oxide-coated particles in the surface enamel layer is 5 to 40 mass% ( Hereinafter, the mass percentage is expressed as%), and the white glaze is a titanium oxide-containing glaze, and the total content of titanium oxide in the surface enamel layer is 10 to 50% as TiO ₂ , more preferably Ti
It is preferable that O ₂ be 15 to 40%.

In the above-mentioned first invention and the first to twenty-third preferred embodiments of the first invention, the white glaze of the surface enamel layer is preferably a white pigment such as titanium oxide. It may be. In the first invention and the first to twenty-third preferred embodiments of the first invention, the metal substrate is a cold-rolled steel plate, an aluminum-plated steel plate, or a Zn-Al alloy-plated steel plate. Preferably, when a cold-rolled steel sheet is used as the metal substrate, it is preferable to use a cold-rolled steel sheet that is a low-carbon steel sheet or a cold-rolled steel sheet that is a stainless steel sheet. It is more preferable to use.

In a second aspect of the present invention, a glaze under the enamel is applied to the surface of the cold-rolled steel sheet and then fired, and the surface of the resulting enamel layer contains a powder composed of particles coated with titanium oxide and a white glaze. A method of manufacturing a reflective screen, comprising applying a glaze on an enamel, followed by firing at 700 to 850 ° C, more preferably 730 to 810 ° C. A third invention is to apply a powder composed of titanium oxide-coated particles and a glaze on an enamel containing a white glaze to the surface of an aluminum-plated steel plate or a Zn-Al alloy-plated steel plate, and then fire at 400 to 600 ° C. A method for manufacturing a reflective screen, characterized in that:

In the second and third aspects of the present invention, the above-mentioned enamel glaze may be coated with a titanium oxide on a mud obtained by pulverizing a mixture of an enamel frit containing white glaze and water. The enamel glaze is preferably obtained by adding and mixing a powder composed of coated particles (the first preferred embodiment of the second invention and the first preferred embodiment of the third invention). 4th
After applying the glaze under the enamel to the surface of the cold-rolled steel sheet,
After baking, on the surface of the obtained base enamel layer, at least two kinds of powders each composed of titanium oxide-coated particles, each having a different average particle size, a white glaze, and more preferably a transparent glaze. Apply enamel glaze to contain,
Thereafter, it is fired at 700 to 850 ° C, more preferably at 730 to 810 ° C, and is a method of manufacturing a reflective screen.

According to a fifth aspect of the present invention, at least two kinds of powders each composed of titanium oxide-coated particles, each having a different average particle diameter, and a white glaze are provided on the surface of an aluminum-plated steel sheet or a Zn-Al alloy-plated steel sheet. And, more preferably, a glaze over enamel containing a transparent glaze,
Thereafter, it is fired at 400 to 600 ° C. to produce a reflective screen.

In the fourth and fifth aspects of the present invention, the glaze on the enamel is obtained by pulverizing a mixture of a white glaze, more preferably a frit for enamel containing a transparent glaze, and water. It is preferable to use an enamel glaze obtained by adding and mixing at least two kinds of powders, each of which is composed of titanium oxide-coated particles, each having a different average particle diameter, to the muddy material (the fourth invention) First preferred embodiment of the present invention, and the first preferred embodiment of the fifth invention).

Further, the second invention, the first preferred embodiment of the second invention, the third invention, the first preferred embodiment of the third invention, the fourth invention, and the fourth invention Preferred Embodiment 1 of Embodiment 5
In the first preferred embodiment of the fifth invention and the fifth invention, the particle diameter of the titanium oxide-coated particles is preferably 100 μm or less, more preferably 80 μm or less (the second invention of the second invention). Of the third aspect, the second aspect of the third aspect, the third aspect, the second aspect of the fourth aspect, the third aspect, and the fifth aspect of the invention. 2 preferred embodiment, 3rd preferred embodiment).

Further, the first to third preferred embodiments of the second invention and the second invention described above, the first to third preferred embodiments of the third invention and the third invention, and the third preferred embodiment. , The fourth invention,
In the first preferred embodiment to the third preferred embodiment of the fourth invention, the fifth invention, and the first preferred embodiment to the third preferred embodiment of the fifth invention, the above-described titanium oxide-coated particles are preferably mica. It is preferable that the surface of the particle is a particle coated with titanium oxide (the fourth to seventh preferred embodiments of the second invention, the third to the seventh preferred embodiments).
Fourth preferred embodiment to seventh preferred embodiment of the invention, fourth preferred embodiment to seventh preferred embodiment of the fourth invention, fourth preferred embodiment of the fifth invention
Preferred embodiment to seventh preferred embodiment).

Further, the fourth to seventh preferred embodiments of the second invention described above, the fourth to seventh preferred embodiments of the third invention, and the fourth preferred embodiment of the fourth invention. In the aspect to the seventh preferred aspect and the fourth to seventh preferred aspects of the fifth invention, the mica particles are preferably sheet-like mica particles (the eighth preferred aspect of the second invention). Aspects to eleventh preferred aspects, eighth preferred aspects to eleventh preferred aspects of the third invention,
Eighth to eleventh preferred aspects of the fourth invention, and eighth to eleventh preferred aspects of the fifth invention).

In the first to eleventh preferred embodiments of the second to fifth inventions and the second to fifth inventions, respectively, the enamel containing the white glaze described above may be used. The top glaze may be an enamel top glaze, preferably containing a white pigment such as titanium oxide. In the first preferred embodiment of the second invention and the first preferred embodiment of the third invention, the mixture of the enamel frit containing white glaze and water is preferably titanium oxide or the like. And a mixture of white pigment, enamel frit and water.

Further, in the first preferred embodiment of the fourth invention and the first preferred embodiment of the fifth invention, an enamel frit containing the white glaze, more preferably a transparent glaze, The mixture with water may be a mixture of a white pigment, preferably titanium oxide, an enamel frit, preferably containing a transparent glaze, and water.

[0023]

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, the present invention will be described in more detail. Means for Solving the Problems The present inventors have conducted intensive studies in order to solve the above-mentioned problems, and as a result, have found the following findings, leading to the present invention. (1) Reflective screen with improved sharpness function (first invention):
By forming an enamel layer containing titanium oxide-coated particles and a white glaze as a surface film of the reflection screen (hereinafter, an enamel layer as a surface film of the reflection screen is referred to as a surface enamel layer), the image is excellent in sharpness. However, it is possible to obtain a reflection screen which is clear, has sufficient reflection luminance and a wide viewing angle, and has improved sharpness function with less halation.

(2) Reflective screen with improved sharpness / diffuse reflective function (first preferred embodiment of the first invention): An enamel layer containing titanium oxide-coated particles and white glaze as a surface film of the reflective screen (: Surface enamel layer)
By imparting a predetermined surface roughness to the surface of the surface enamel layer, the diffuse reflection and the regular reflection are highly fused, having a wider viewing angle, excellent clarity, clear images, and sufficient reflection. It is possible to obtain a reflection screen having improved brightness and diffuse reflection function, which has luminance and hardly shows halation.

(3) Reflective screen with improved sharpness / erasability function (second preferred embodiment of the first invention): As the surface film of the reflective screen, titanium oxide-coated particles, white glaze, and more preferably Further, by forming an enamel layer containing transparent glaze (surface enamel layer) and regulating both the surface roughness and the glossiness of the surface enamel layer to be within a specific range, it is possible to draw with a marker or the like. To obtain a reflective screen with improved erasability function of writing, excellent clarity, clear image, sufficient reflection luminance and wide viewing angle, and improved clarity / erasability function with little halation Can be.

(4) Method for manufacturing reflective screen with improved sharpness function and reflective screen with improved sharpness / diffuse reflective function (second invention and third invention): A powder composed of titanium oxide-coated particles and an enamel glaze containing a white glaze are applied, and thereafter, when the metal substrate is a cold-rolled steel plate, 700 to 850 ° C., more preferably 730 to 850 ° C.
When baked at 10 ° C (second invention) and the metal substrate is an aluminum-plated steel plate or a Zn-Al alloy-plated steel plate,
Firing at 400-600 ° C. (third invention).

According to the above-described manufacturing method, the surface hardness (Mohs hardness ≧ 4) which cannot be obtained by the conventional screen can be obtained by firing the enamel glaze coating layer within the above-mentioned temperature range. Writing), erasing by marker eraser, etc. is possible, reflective screen with improved scratch resistance, impact resistance, stain resistance, and recovery from cleaning, improved reflective screen function, improved reflective / diffuse reflective function A reflective screen can be obtained.

In the second and third aspects of the present invention, as the above-mentioned enamel glaze, a mud (hereinafter also referred to as a slip) obtained by pulverizing a mixture of an enamel frit and water may be used. By using an enamel glaze obtained by adding and mixing a powder composed of titanium oxide-coated particles, it is possible to obtain a reflection screen having excellent clarity, a clear image, and sufficient reflection luminance ( First preferred embodiment of the second invention, first preferred embodiment of the third invention).

(5) Method for producing reflective screen with improved sharpness / erasability function (fourth and fifth inventions): In the formation of the above-mentioned surface enamel layer, both are composed of titanium oxide-coated particles. Applying a glaze on enamel containing at least two kinds of powders each having a different average particle size, a white glaze, and more preferably a transparent glaze, and then, when the metal substrate is a cold-rolled steel plate, 700 g -850 ° C, more preferably 730-810 ° C (fourth invention), and when the metal substrate is an aluminum-plated steel plate or Zn-Al-plated steel plate, it is fired at 400-600 ° C (fifth invention). ).

According to the above-described manufacturing method, both the unevenness of the screen surface and the glossiness are regulated within a specific range,
The function of erasing the writing with markers etc. is improved, and furthermore, it is possible to prevent the reduction of sharpness and the viewing angle which are the contradictory effects due to the regulation of unevenness, and the image with excellent sharpness It is possible to obtain a reflection screen which is clear, has sufficient reflection luminance and a wide viewing angle, and has improved sharpness and erasability functions with little halation.

In the fourth and fifth aspects of the present invention, as the above-mentioned enamel glaze, a muddy substance (slip) obtained by pulverizing a mixture of an enamel frit and water is coated with titanium oxide. By using at least two kinds of powders having different average particle diameters composed of particles and adding and mixing, a reflective screen having excellent clarity, a clear image, and a sufficient reflection luminance is obtained by using an enamel glaze. (First preferred embodiment of the fourth invention, first preferred embodiment of the fifth invention).

Hereinafter, the present invention will be described in the order of I. metal base material, II. First invention (reflection screen), III. Second invention to fifth invention (reflection screen manufacturing method). In addition,
Hereinafter, the preferable content of each element in the glaze, the raw material such as the powder composed of the titanium oxide-coated particles, the enamel layer and the like according to the present invention is shown as the content of each element in terms of oxide described later.

I. Metal substrate: The metal substrate in the present invention is not particularly limited, but a cold-rolled steel plate is preferable, and a low-carbon steel plate or a stainless steel plate is preferable as the cold-rolled steel plate. Further, as the cold-rolled steel sheet, it is preferable to use a nickel-plated cold-rolled steel sheet for improving the adhesion between the steel sheet and the glaze, and further, a nickel-plated low-carbon steel sheet or a stainless steel sheet is used. It is more preferable to use a cold-rolled steel sheet.

The low-carbon steel sheet has a carbon content of 200 mass-ppm or less, more preferably 100 mass-ppm or less, still more preferably 50 mass-ppm or less.
It is preferable to use an ultra-low carbon steel sheet having a mass-ppm or less.
Further, as the nickel plating, electroless nickel plating (nickel flash plating) is preferable.

As the electroless nickel plating, an immersion method in which a steel sheet is immersed in a nickel-containing solution such as a nickel sulfate solution can be used. Further, as the metal substrate in the present invention, aluminum-plated steel sheet, Zn-Al
It is also preferable to use an alloy plated steel sheet. In addition, as for the above-mentioned Zn-Al alloy plated steel sheet, the aluminum content in the Zn-Al alloy plated layer is 4 to 70% by mass (%),
It is preferable that the Zn—Al alloy plated steel sheet contains zinc and inevitable impurities as a balance in the Zn—Al alloy plated layer, or an additive substance for further improving the properties of the plated film.

II. First Invention (Reflective Screen): First
The present invention is a reflective screen having a surface enamel layer containing titanium oxide-coated particles and white glaze on the outer surface of a metal substrate. According to the present invention, an enamel layer containing titanium oxide-coated particles and a white glaze (a surface enamel layer) is formed as a surface film of a reflective screen, so that the image is excellent in sharpness and the image is clear and sufficient reflection is achieved. It is possible to obtain a reflection screen having improved brightness and a reduced viewing angle, having a high brightness and a wide viewing angle.

This is because, by incorporating titanium oxide-coated particles in the surface film of the reflection screen, the sharpness is improved, and irregularities are formed on the surface of the surface enamel layer.
This is because the diffuse reflectivity is improved and halation is suppressed. In the present invention, the content of the titanium oxide-coated particles in the surface enamel layer is preferably 5 to 40% by mass (%), and more preferably 10 to 40%.

When the content of the titanium oxide-coated particles in the surface enamel layer is less than 5%, the effect of improving sharpness and diffuse reflection is small. On the other hand, when the content of the titanium oxide-coated particles is 5
% Or more, not only the sharpness is improved, but also the unevenness of the surface is increased, the diffuse reflection property is improved, and a reflective screen having an excellent viewing angle can be obtained.

Conversely, when the content of the titanium oxide-coated particles in the surface enamel layer exceeds 40%, the surface roughness (Ra) becomes excessively large, and the image becomes unclear. In the present invention, a white pigment such as titanium oxide may be preferably used as the white glaze for the surface enamel layer. In the present invention, the above-mentioned white glaze is preferably a titanium oxide-containing glaze. Further, the titanium oxide content of the surface enamel layer (: the total amount of titanium oxide including titanium oxide of the titanium oxide-coated particles) Content) is 10 to 50 as TiO ₂
%, And more preferably 15 to 40% as TiO _2.

This is because the content of titanium oxide in the surface enamel layer (: the total content of titanium oxide including titanium oxide in the titanium oxide-coated particles, hereinafter also referred to as the total content of titanium oxide) is 10% as TiO _2. By stipulating the above,
While the base surface is concealed, the surface layer can be whitened to obtain a reflective screen with excellent color tone reproducibility of the image,
Conversely, when the total content of titanium oxide in the surface enamel layer exceeds 50% as TiO ₂ , the adhesion of the enamel layer is reduced.

In the present invention, the particle diameter of the titanium oxide-coated particles is preferably 100 μm or less, more preferably 80 μm or less. This is because, when the particle diameter of the titanium oxide-coated particles exceeds 100 μm, the surface roughness Ra of the surface enamel layer becomes excessively large and the image becomes unclear as described above.

In the present invention, the particle diameter of the titanium oxide-coated particles is more preferably 5 μm or more and 80 μm or less. This is because by regulating the lower limit of the particle size, the diffuse reflectivity is further improved. Further, in the present invention, the titanium oxide-coated particles are preferably particles in which the surface of mica particles is coated with titanium oxide,
Further, it is more preferable that the mica particles are lamellar mica particles.

This is because the mica particles are colorless and the titanium oxide-coated mica particles have excellent light reflectivity, and the use of thin plate mica particles as the mica particles increases the light reflection luminance of the enamel layer. is there. In the first invention, the surface enamel layer has a surface roughness Ra (arithmetic mean roughness, JIS B 0601-1994) of preferably 2.5 μm or more,
More preferably 2.5 μm or more, 10 μm or less, and more preferably 2.
More preferably, it is 7 μm or more and 10 μm or less (a first preferred embodiment of the first invention).

This is because, by setting the surface roughness Ra (arithmetic mean roughness) of the surface enamel layer to the above range, diffuse reflection and specular reflection are highly fused, and a wider viewing angle is obtained and sharpness is improved. This is because it is possible to obtain a reflection screen with improved sharpness / diffuse reflection function, which is excellent in image quality, has sufficient reflection luminance, and hardly shows halation.

When the surface enamel layer has a surface roughness Ra of less than 2.5 μm, the diffuse reflectivity decreases, and the surface roughness Ra is 10 μm.
If it exceeds, a clear image cannot be obtained. The surface roughness Ra (arithmetic mean roughness) of the surface enamel layer can be controlled by adjusting the content of the titanium oxide-coated particles of the enamel layer and the sintering temperature within a preferable range in the present invention.

In the first aspect of the present invention, the surface enamel layer preferably has a surface roughness Ra (arithmetic mean roughness) of 1.5 μm.
m or more, less than 2.5 μm, more preferably 1.7 μm or more,
2.0 μm or less, more preferably 1.70 μm or more, 1.95 μm
Or less, most preferably 1.70 μm or more and 1.90 μm or less, and glossiness: Gs (45 °) (JIS Z 8741-1983)
It is preferably 15 to 25% (second preferred embodiment of the first invention).

This is because the surface roughness of the surface enamel layer: Ra (arithmetic mean roughness) and the glossiness: Gs (45 °) are both controlled within the above ranges, so that the erasability of a picture by a marker or the like can be improved. It is possible to obtain a reflection screen with improved sharpness, excellent image clarity, sharp reflection, sufficient reflection luminance and wide viewing angle, and improved sharpness and erasability with less halation. is there.

When the surface roughness of the surface enamel layer: Ra is less than 1.5 μm, the diffuse reflectivity decreases, and the surface roughness: Ra is 2.5 μm.
If it is more than m, the erasability function is reduced. Further, when the glossiness: Gs (45 °) is less than 15%, the erasability function decreases, and when the glossiness: Gs (45 °) exceeds 25%, halation increases. The surface roughness of the surface enamel layer described above: Ra (arithmetic mean roughness) and glossiness: Gs (45 °)
The content can be controlled by adjusting the content of the titanium oxide-coated particles in the enamel layer, the particle size distribution of the titanium oxide-coated particles, and the sintering temperature within the preferable ranges in the present invention.

In the second preferred embodiment of the first invention, it is more preferable that the surface enamel layer further contains a transparent glaze in addition to the white glaze. This is because the surface enamel layer contains a transparent glaze, which enhances the sharpness and diffuse reflection of the titanium oxide-coated particles buried inside the surface enamel layer, providing excellent sharpness and a wide viewing angle. ,
This is because a reflection screen with less halation can be obtained.

As described above, the surface enamel layer containing the white glaze and the transparent glaze in the second preferred embodiment of the first invention has a total content of titanium oxide of 10 to 50 as TiO ₂ as described above. %, More preferably 15 as TiO ₂
It is preferably a surface enamel layer containing 240% and B ₂ O ₃ １〜1-25%. The above-mentioned reflection screen of the second preferred embodiment of the first invention can be easily manufactured, in particular, by the method of manufacturing the reflection screen of the fourth invention or the fifth invention described later.

The thickness of the surface enamel layer containing the titanium oxide-coated particles and the white glaze, which is the surface film of the reflection screen in the present invention, is preferably 10 to 300 μm. This is because when the film thickness of the surface enamel layer is less than 10 μm, the concealing property of the underlayer is inferior, and when it exceeds 300 μm, warpage occurs and it becomes difficult to control the surface roughness.

As the white glaze for the surface enamel layer in the present invention, a high-concealment glaze which is white and whose base surface cannot be seen through is preferable. This is because, by using the above-mentioned white high-glazing glaze, the base surface is concealed and the surface layer is whitened, so that a reflective screen having excellent color tone reproducibility of an image can be obtained.

As the above-mentioned white highly concealable glaze, a glaze containing one or more selected from titanium oxide, zirconium oxide, antimony oxide and zinc oxide in view of the projecting and reflecting properties of the reflective screen. preferable.
The above-mentioned white high-concealment glaze may be a glaze containing one or more white pigments selected from titanium oxide, zirconium oxide, antimony oxide and zinc oxide.

When a cold-rolled steel sheet is used as the metal substrate in the present invention, the glaze containing at least titanium oxide should be used in view of the projecting and reflecting properties of the reflective screen. (Hereinafter also referred to as a titanium oxide-containing glaze) is particularly preferred. The titanium oxide-containing glaze described above, glaze containing TiO ₂ 10 to 30% are preferred.

As the glaze containing titanium oxide, TiO ₂
10 to 30%, with the balance being SiO ₂ : 0 to 80%, Al _{2
O 3: 0~20%, B 2} O 3: 0~25%, Na 2 O: 0~20%, K 2 O: 0
_{~20%, Li 2 O: 0~20} %, P 2 O 5: 0~10%, ZrO 2: 0 ~
20%, BaO: 0-15%, CaO: 0-15%, MgO: 0-5%, Pb
O: 0~40%, ZnO: 0~50 %, CaF 2: can be used TiO ₂ system glaze containing like 0-10%.

When an aluminum-plated steel sheet or a Zn—Al alloy-plated steel sheet is used as the metal substrate in the present invention, the above-mentioned white high-concealment glaze may be a low-temperature baking property and a projection or reflection property of a reflection screen. From the viewpoint of, a glaze containing phosphorus oxide (hereinafter also referred to as a phosphoric acid glaze), at least titanium oxide as a white pigment,
Glazes added with one or more selected from zirconium oxide, antimony oxide and zinc oxide are particularly preferred.

As the above-mentioned phosphoric acid glaze, P ₂ O ₅
Glazes containing ~ 70% are preferred. The phosphoric acid glaze contains 40 to 70% of P ₂ O ₅ , and the balance is SiO ₂ : 0.
_{~40%, Al 2 O 3:} 0~50%, B 2 O 3: 0~25%, Na 2 O: 0~
_{20%, K 2 O: 0~20} %, Li 2 O: 0~20%, TiO 2: 0~30%,
Sb ₂ O ₃ : 0 to 25%, ZnO: 0 to 20%, BaO: 0 to 15%, CaO: 0
A P ₂ O ₅ glaze containing 1515%, MgO: 0 to 10%, PbO: 0 to 10%, SrO: 0 to 20% can be used.

Further, the above-mentioned transparent glaze for the surface enamel layer is used.
Although it is not particularly limited,
It is preferable to use glass. Hokei-based glass
As SiO_TwoThe 40-80%, B_TwoO_Three5-25%, Na_TwoO,
K_TwoO and Li_TwoTotal amount of one or more selected from O
5 to 25%, with the balance being Al_TwoO_Three: 0 to 10%, Ba
O: 0 to 15%, CaO: 0 to 15%, MgO: 0 to 5%, Fe_TwoO _Three: 0-
2%, ZnO: 0 ~ 10%, P_TwoO_Five: 0-20%, TiO_Two: 0-30
%, CaF_Two: Hokei-based gala containing 0-10% etc.
Is preferred.

The first invention and its more preferred embodiments have been described above. The more preferred composition of the surface enamel layer in the first invention is as follows. (1) When cold-rolled steel sheet is used as the metal substrate: (1-1) Reflective screen with improved sharpness and diffuse reflection function (first preferred embodiment of the first invention): As described above, the surface The white glaze in the enamel layer is a titanium oxide-containing glaze, and the total content of titanium oxide in the surface enamel layer (: the total content of titanium oxide including titanium oxide in the titanium oxide-coated particles) is Ti
O ₂ as 10-50%, more preferably 15% to 40% as TiO ₂
And one or more selected from Na ₂ O, K ₂ O and Li ₂ O in a total amount of 5 to 25%, B ₂ O ₃ of 1 to 25%, SiO ₂ and / or Al ₂ O It is preferable that the surface enamel layer contains 15 to 50% in total of ₃ .

(1-2) Reflective screen with improved sharpness / erasability function (second preferred embodiment of the first invention): As described above, the white glaze of the surface enamel layer is a glaze containing titanium oxide. ,
Total content of titanium oxide in surface enamel layer (: Total content of titanium oxide including titanium oxide in titanium oxide-coated particles)
15 but 10-50% as TiO _2, more preferably a TiO ₂
4040%, one or two or more selected from Na ₂ O, K ₂ O and Li ₂ O in a total amount of 5 to 30%, B ₂ O ₃ of 1 to 25%,
The surface enamel layer preferably contains 20 to 55% of SiO ₂ and / or Al ₂ O ₃ in total.

(2) When using an aluminum-plated steel plate or a Zn-Al alloy-plated steel plate as the metal substrate: (2-1) Reflective screen with improved sharpness / diffuse reflection function (the first screen of the first invention) Preferred embodiment): As described above, the white glaze of the surface enamel layer is a titanium oxide-containing glaze, and the total content of titanium oxide in the surface enamel layer (: the total content of titanium oxide including titanium oxide in the titanium oxide-coated particles) Amount) but Ti
O ₂ as 10-50%, more preferably 15% to 40% as TiO ₂
And a surface enamel layer containing 20 to 60% of P ₂ O ₅ and ₂ to 25% in total of one or more selected from Na ₂ O, K ₂ O and Li ₂ O. preferable.

Further, the above-mentioned surface enamel layer may further contain BaO and / or CaO in a total amount of 2 to 2 in the above composition.
A surface enamel layer containing 15% is more preferable, and further, in the above composition, BaO and / or
It contains 2 to 15% of CaO in total and 2 to 3% of Sb ₂ O ₃ .
It is particularly preferable that the surface enamel layer contains 15%, ZnO 1 to 15%, and B ₂ O ₃ 1 to 25%.

(2-2) Reflective screen with improved sharpness / erasability function (second preferred embodiment of the first invention): As described above, the white glaze of the surface enamel layer is a glaze containing titanium oxide. ,
Total content of titanium oxide in surface enamel layer (: Total content of titanium oxide including titanium oxide in titanium oxide-coated particles)
15 but 10-50% as TiO _2, more preferably a TiO ₂
4040%, P ₂ O ₅ from 20-60%, Na ₂ O, K ₂ O and Li ₂ O
One or more selected from 2 to 25% in total amount,
The B ₂ O ₃ is preferably a surface enamel layer containing 1% to 25%.

Further, the above-mentioned surface enamel layer may further contain BaO and / or CaO in a total amount of 2 to 2 in the above composition.
A surface enamel layer containing 15% is more preferable, and further, in the above composition, BaO and / or
It contains 2 to 15% of CaO in total and 2 to 3% of Sb ₂ O ₃ .
It is particularly preferable that the surface enamel layer contains 15% of ZnO and 1 to 15% of ZnO.

In the composition of the surface enamel layer of (1) and (2), B ₂ O ₃ , Na ₂ O, K ₂ O, Li ₂ O, BaO and Ca
O 2 also has a function as a melting agent during firing. III. Second to Fifth Inventions (Method of Manufacturing Reflective Screen): III.-1. 2nd invention, 3rd invention (method of manufacturing reflective screen): The 2nd invention is a preferred method of manufacturing the reflective screen of the above-mentioned 1st invention, in which a glaze under enamel is applied to the surface of a cold-rolled steel sheet. After the application, it is baked, and the surface of the obtained enamel layer is coated with an enamel glaze containing a powder composed of titanium oxide-coated particles and a white glaze, and then 700 to 850
C., more preferably 730-810.degree. C., for producing a reflective screen.

The third invention is also a preferred method of manufacturing the reflection screen according to the first invention, wherein the surface of an aluminum-plated steel plate or a Zn—Al alloy-plated steel plate is coated with titanium oxide-coated particles. Apply the glaze on the enamel containing the composed powder and white glaze, then 400-600 ℃
This is a method for manufacturing a reflective screen to be fired in the above. In the third aspect of the present invention, from the viewpoint of preventing the plating layer from melting, the adhesiveness is improved because a low melting point glaze such as the above-mentioned phosphoric acid type glaze is preferably used as the glaze for the surface enamel layer. However, it is not always necessary to apply an enamel glaze.

According to the present invention, at the time of forming the surface enamel layer, the conventional enamel glaze coating layer is fired within the above-mentioned temperature range according to the type of the metal base material and the components of the enamel glaze, thereby achieving the conventional screen. Surface hardness (Mohs hardness ≧
4) is obtained.
An erasing operation using a marker-dedicated eraser or the like is possible, and it is possible to obtain a reflection screen with improved sharpness and function, which is excellent in impact resistance, stain resistance, and recovery from washing.

When the metal substrate is a cold-rolled steel sheet and the firing temperature after applying the glaze on the enamel is less than 700 ° C., the surface roughness of the obtained reflection screen becomes too large, and a clear image cannot be obtained. . If the metal substrate is a cold-rolled steel sheet and the firing temperature is higher than 850 ° C., the surface of the surface enamel layer will have no irregularities, the gloss will increase, and the resulting reflective screen will have halation.

If the metal substrate is an aluminum-plated steel plate or a Zn-Al alloy-plated steel plate and the firing temperature after applying the glaze on the enamel is less than 400 ° C., the adhesion of the enamel layer is reduced. If the metal substrate is an aluminum-plated steel plate or a Zn-Al alloy-plated steel plate and the sintering temperature exceeds 600 ° C., there is a problem that the plating layer is melted.

In the second and third aspects of the present invention, the enamel glaze forming the surface enamel layer is obtained by pulverizing a mixture of water and an enamel frit containing a white glaze. It is preferable to use a glaze on an enamel obtained by adding and mixing a powder composed of titanium oxide-coated particles to the substance (: slip) (the first preferred embodiment of the second invention, the third invention) First preferred embodiment).

This is achieved by adding and mixing a powder composed of titanium oxide-coated particles after forming the slip.
It is possible to prevent the pulverization of the titanium oxide-coated particles, to form a surface enamel layer containing the titanium oxide-coated particles of a predetermined particle size, to provide a reflection screen having excellent sharpness, clear images, and sufficient reflection luminance. This is because they can be obtained. The enamel underglaze in the second invention is not particularly limited, but an enamel underglaze containing a SiO ₂ glaze, a P ₂ O ₅ glaze, or the like can be used.

[0072] As the SiO ₂ based glaze, the SiO ₂ containing 20% to 80%, the _{balance, TiO 2: 0~15%, ZrO} 2: 0~20%, B 2
_{O 3: 0~25%, Al 2} O 3: 0~10%, Na 2 O: 0~20%, Li
₂ O: 0-20%, K ₂ O: 0-20%, PbO: 0-40%, ZnO: 0-5
0%, BaO: 0~15%, CaF 2: 0~10%, CoO: 0~20%,
A SiO ₂ glaze containing NiO: 0 to 20%, MnO: 0 to 20%, or the like is preferable.

As a P ₂ O ₅ glaze, P ₂ O ₅ is 30 to 70
%, The balance being TiO ₂ : 0 to 15%, ZrO ₂ : 0 to 15
_{%, B 2 O 3: 0~35} %, Al 2 O 3: 0~15%, Na 2 O: 0~20
%, Li ₂ O: 0-20%, K ₂ O: 0-20%, PbO: 0-50%, Z
nO: 0-50%, BaO: 0-15%, CoO: 0-20%, NiO: 0-20
%, MnO: preferably P ₂ O ₅ based glazes containing like 0-20%.

Further, as the enamel underglaze, from the viewpoint of improving the adhesion of the slip and controlling the foam structure in the enamel layer,
Further, it is preferable to contain clay or silica stone. Further, as the titanium oxide-coated particles and the white glaze in the enamel glaze in the second and third inventions, it is preferable to use the titanium oxide-coated particles and the white glaze in the first invention described above.

The above-mentioned white glaze may be one or more white pigments selected from titanium oxide, zirconium oxide, antimony oxide and zinc oxide. In the second and third aspects of the present invention, the content of the titanium oxide-coated particles of the glaze on the enamel is determined by a white glaze:
It is preferably 5 to 50 parts by weight based on 100 parts by weight.

When the content of the titanium oxide-coated particles is less than 5 parts by weight, the effect of improving sharpness is small, and when it exceeds 50 parts by weight, the surface roughness Ra of the surface enamel layer is excessively large. And the image becomes unclear. As described above, the second invention and the third invention
In the second and third aspects of the present invention, the content of the titanium oxide-coated particles of the glaze on the enamel and the firing temperature at the time of firing the glaze on the surface are adjusted within the preferred ranges described above. By setting the surface roughness Ra of the surface enamel layer to 2.5 μm or more, it is possible to manufacture the reflection screen with improved sharpness / diffuse reflection function which is the first preferred embodiment of the first invention. it can.

The preferred composition of the surface enamel layer of the reflection screen manufactured according to the second and third inventions is the same as the preferred composition of the surface enamel layer of the reflection screen of the first invention. . Further, the glaze method of the lower enamel glaze and the upper enamel glaze in the second invention and the third invention is not particularly limited, and a spray method, a dipping method, an electrostatic method, an electrodeposition method, or the like may be used. it can.

III.-2. Fourth invention, fifth invention (a method of manufacturing a reflective screen): The fourth invention is directed to the first invention.
The present invention is a method for producing a reflection screen with improved sharpness / erasability function according to the second preferred embodiment of the invention, in which a glaze under the enamel is applied to the surface of a cold-rolled steel sheet, and then baked. The surface is coated with at least two kinds of powders, both composed of titanium oxide-coated particles, having different average particle diameters, a white glaze, and preferably an enamel glaze containing a transparent glaze, and then at 700 to 850 ° C. More preferably 730 to 810 ° C
This is a method for manufacturing a reflective screen to be fired in the above.

A fifth invention is also a method for producing a reflection screen with improved sharpness / erasability function according to the second preferred embodiment of the first invention described above, and comprises an aluminum-plated steel sheet or a Zn-based reflection screen. On the surface of the Al alloy-plated steel sheet, apply at least two kinds of powders, each composed of titanium oxide-coated particles, each having a different average particle size, a white glaze, and preferably an enamel glaze containing a transparent glaze. And
After that, it is a method of manufacturing a reflection screen which is fired at 400 to 600 ° C.

In the fifth aspect of the present invention, as in the third aspect of the invention, from the viewpoint of preventing the plating layer from melting, the above-mentioned phosphoric acid glaze is preferably used as the glaze for the surface enamel layer. Due to the use of the low melting point glaze, the adhesion is improved, and the application of the glaze under the enamel is not always necessary. The above-described fourth and fifth aspects of the invention are suitably used as a method of manufacturing the reflection screen with improved sharpness / erasability according to the second aspect of the first aspect of the invention.

That is, according to the fourth and fifth aspects of the present invention, the surface enamel layer is made to contain titanium oxide-coated particles having at least two kinds of particle size distributions having different average particle diameters, thereby obtaining the surface enamel. The unevenness of the layer is regulated,
The erasure function of a drawing by a marker etc. is improved. The at least two kinds of powders composed of the above-described titanium oxide-coated particles and having different average particle diameters include a powder composed of titanium oxide-coated particles and having an average particle diameter of 10 to 60 μm and an average particle diameter composed of titanium oxide-coated particles. It is preferred to use both powders of 5 to 25 μm.

In the present invention, it is more preferable to use at least two kinds of powders having an average particle diameter in the above-mentioned range and having a difference of 5 μm or more. The powder having a small average particle diameter contributes to the improvement of the erasability function, and the powder having a large average particle diameter contributes to the improvement of the sharpness function. In the present invention, by setting the difference in the average particle diameter to 5 μm or more, the unevenness of the surface enamel layer is further restricted, and the erasability function is further improved.

The mixing ratio of the above two types of powder is such that the powder having a small average particle size is 80 to 20 parts by weight, and the powder having a small average particle size is 20 to 80 parts by weight, more preferably 20 to 80 parts by weight. The powder having a small average particle diameter is preferably 65 to 35 parts by weight with respect to the powder having a large average particle diameter: 35 to 65 parts by weight. In the present invention, it is more preferable to blend a transparent glaze into the enamel glaze.

This is because, by blending a transparent glaze in the enamel top glaze, the titanium oxide-coated particles buried in the surface enamel layer have the effect of improving the sharpness and diffuse reflection, and the above-described unevenness is obtained. This is because it is possible to prevent a reduction in image sharpness and a decrease in diffuse reflection which are contradictory effects due to the regulation, and to obtain a reflection screen having excellent image sharpness, a wide viewing angle, and little halation.

The enamel under glaze in the fourth invention includes:
Although there is no particular limitation, it is preferable to use the glaze under the enamel according to the second invention. Further, as the titanium oxide-coated particles and the white glaze in the enamel glaze in the fourth and fifth inventions, it is preferable to use the titanium oxide-coated particles and the white glaze in the first invention described above.

The above-mentioned white glaze may be a white pigment which is one or more selected from titanium oxide, zirconium oxide, antimony oxide and zinc oxide. Further, the transparent glaze is not particularly limited, but it is preferable to use Hokekei glass.

As the borosilicate glass, SiO_TwoTo 40
~ 80%, B_TwoO_Three5-25%, Na_TwoOK_TwoO and Li_TwoFrom O
Contains 5 to 25% in total of one or more selected types
And Al as the rest_TwoO_Three: 0 to 10%, BaO: 0 to 15%, CaO: 0
~ 15%, MgO: 0 ~ 5%, Fe_TwoO _Three: 0-2%, ZnO: 0-10
%, P_TwoO_Five: 0-20%, TiO_Two: 0 to 30%, CaF_Two: 0 ~ 10%
And the like are preferred.

In the fourth and fifth inventions, the content of the titanium oxide-coated particles in the enamel glaze is 5 to 50 parts by weight based on 100 parts by weight of the total amount of the white glaze and the transparent glaze. Is preferred. When the content of the titanium oxide-coated particles is less than 5 parts by weight, the effect of improving the sharpness is small. Conversely, when the content exceeds 50 parts by weight, the surface roughness of the surface enamel layer: Ra
Becomes excessively large, and the image becomes unclear.

The content of the transparent glaze in the above-mentioned enamel glaze is preferably 5 to 50 parts by weight based on 100 parts by weight of the total amount of the white glaze and the transparent glaze. When the content of the transparent glaze is less than 5 parts by weight, the sharpness, the viewing angle improving effect and the halation suppressing effect are deteriorated, and when it exceeds 50 parts by weight, the concealing property of the base is inferior and the color tone of the image Reproducibility also decreases.

The above parts by weight are parts by weight converted into parts by weight after enamel glaze firing. Further, according to the fourth and fifth aspects of the present invention, when the surface enamel layer is formed, the enamel glaze coating layer is formed within the above-mentioned temperature range according to the type of the metal substrate and the component of the enamel glaze. By baking, surface hardness (Mohs hardness ≧ 4) not available in conventional screens can be obtained, and depiction (writing) with a marker or the like, erasing with a marker-dedicated eraser, etc. is possible, impact resistance, contamination resistance, and cleaning Excellent clarity with excellent recoverability
A reflective screen with improved erasability can be obtained.

If the metal substrate is a cold-rolled steel sheet and the firing temperature after applying the glaze on the enamel is less than 700 ° C., the surface roughness of the obtained reflection screen becomes too large, and a clear image cannot be obtained. In addition, the erasability is reduced. If the metal substrate is a cold-rolled steel sheet and the firing temperature is higher than 850 ° C., the surface of the surface enamel layer will have no irregularities and the gloss will be too high, resulting in halation in the resulting reflective screen.

If the metal substrate is an aluminum-plated steel plate or a Zn-Al alloy-plated steel plate and the firing temperature after applying the glaze on the enamel is less than 400 ° C., the adhesion of the enamel layer is reduced. If the metal substrate is an aluminum-plated steel plate or a Zn-Al alloy-plated steel plate and the sintering temperature exceeds 600 ° C., there is a problem that the plating layer is melted.

Further, in the above fourth and fifth inventions, the glaze on the enamel which forms the surface enamel layer is a mixture of a white glaze, preferably a frit for enamel containing a transparent glaze, and water. To the mud (slip) obtained by the pulverization, at least two kinds of powders each composed of titanium oxide-coated particles and having different average particle diameters are added and mixed. It is preferable (the first preferred embodiment of the fourth invention, the first preferred embodiment of the fifth invention).

This is accomplished by adding and mixing a powder composed of titanium oxide-coated particles after the slip formation.
It is possible to prevent the pulverization of the titanium oxide-coated particles, to form a surface enamel layer containing the titanium oxide-coated particles of a predetermined particle size, to provide a reflection screen having excellent sharpness, clear images, and sufficient reflection luminance. This is because they can be obtained. The preferred composition of the surface enamel layer of the reflective screen manufactured according to the fourth and fifth aspects is the same as the preferred composition of the surface enamel layer of the reflective screen of the first aspect.

Further, the method for applying the glaze under the enamel and the glaze on the enamel according to the fourth and fifth aspects of the present invention is not particularly limited, and includes a spray method, a dipping method, an electrostatic method, an electrodeposition method and the like. Can be used. As described above, the present invention has been described. According to the present invention, the following excellent effects can be obtained.

[First invention] (Reflection screen with improved clarity function, reflection screen with improved clarity / diffuse reflection function and reflection screen with improved clarity / erasability function): Excellent clarity It is possible to obtain a reflection screen having a clear image, sufficient reflection luminance and a wide viewing angle, and having less halation (first invention: reflection screen with improved sharpness function).

By highly diffusing diffuse reflection and specular reflection, it is possible to obtain a reflection screen having a wider viewing angle and almost no halation (first preferred embodiment of the first invention: clear image) Reflective screen with improved diffuse / reflective function). A reflection with excellent erasability function that can be written (written) with a marker for whiteboard, etc., can be easily erased by rubbing with a marker eraser, etc., and easily erased by rubbing with a moist cloth. A screen can be obtained (second preferred embodiment of the first invention:
Reflective screen with improved sharpness and erasability).

[Second to Fifth Inventions] (Method of Manufacturing Reflective Screen): Surface hardness not present in conventional screens (Mohs hardness ≧)
4) is obtained, and a reflective screen having excellent scratch resistance, impact resistance, stain resistance, and recovery from washing can be obtained. Reflective screen with improved sharpness / erasability by using at least two kinds of powders composed of titanium oxide-coated particles and having different average particle diameters, a white glaze, and a glaze on an enamel containing a transparent glaze Can be easily manufactured.

As a glaze on the enamel for forming the surface enamel layer, a mud obtained by grinding a mixture of a white glaze or a frit for enamel containing a transparent glaze and water (:
By adding and mixing a powder composed of titanium oxide-coated particles to the slip), an enamel glaze obtained by mixing is used to provide excellent sharpness, clear images, sufficient reflection luminance and a wide viewing angle. In addition, a reflection screen with less halation can be obtained.

Further, since the reflective screen of the present invention is a processed product of a metal substrate such as a steel plate, it does not have wrinkles unlike fabrics and processed products of vinyl chloride, does not need to maintain tension during production, and can simplify the processing steps. It also has an effect that can be made.

[0101]

EXAMPLES The present invention will be described below more specifically based on examples. The measurement of the characteristic values and the performance evaluation of the reflection screen in this example were performed based on the following methods. (Reflection Luminance :) FIG. 3 shows a method of measuring reflection luminance.

In FIG. 3, 1 is incident light, 2 is reflected light, _3S is a sample of a reflection screen, 10 is a light source, 11 is a light source,
Indicates a luminance meter, and θ indicates a moving angle of the luminance meter 11 with respect to the light source 10. As shown in FIG. 3, a reflective screen sample 3 _S
Center is irradiated with light by the light source 10 from the vertical direction of the luminometer 11, the intensity of the reflected light at the point moved by 5 degrees in the range of each side 75 degrees with respect to the center of the sample 3 _S on the same arc Was measured.

(Surface Roughness of Surface Enamel Layer: Using a Surface Roughness Meter)
(Arithmetic average roughness) (JIS B 0601-1994) was measured. (Glossiness) Using a variable-angle glossmeter, 45-degree specular glossiness [: Gs (45 °)] was measured based on JIS Z 8741-1983.

(Hardness of Surface Enamel Layer) The Mohs hardness of the surface enamel layer of the reflection screen was measured. (Evaluation of image by liquid crystal projector :) The image on the reflection screen projected by the liquid crystal projector was visually evaluated.

The degree of suppression of halation was evaluated according to the following criteria. ：: Almost no halation was observed. ：: Some halation is observed. X: Halation is remarkably observed. (Erasability of drawing marker :)
Painted with different whiteboard markers.

Whiteboard marker: WBMV-LB [trade name, black, manufactured by Pilot Corporation] PMB-102 [trade name, black, manufactured by KOKUYO Co., Ltd.] The following whiteboard marker dedicated eraser is applied, a 500g weight is placed on it, and the operation of pulling the eraser in the horizontal direction is performed a predetermined number of times under a constant speed under a load, and all the drawing markers are The required number of times until disappearance (the required number of erases) was measured.

Eraser: Brush type eraser [trade name: WBE-L, manufactured by Pilot Co., Ltd.] [Examples 1 and 2] (Reflection screen with improved sharpness function using cold-rolled steel sheet as a base material, Reflective screen with improved sharpness and diffuse reflection function): SiO ₂ glaze: 100 parts by weight, clay: 5 parts by weight, silica powder:
10 parts by weight, borax: 0.4 parts by weight, sodium nitrite: 0.15 parts by weight, and water: 47 parts by weight are charged into a ball mill, mixed, pulverized, and a mud (: slip) (under an enamel) Glaze).

A ball mill was prepared by adding a blending material obtained by adding 5 parts by weight of clay, 0.20 parts by weight of potassium chloride, and 50 parts by weight of water to 100 parts by weight of a white glaze (frit for enamel) having the composition shown in Table 1. It was charged, mixed and pulverized to produce a mud (: slip). Next, for the slip: 100 parts by weight (weight conversion after firing) produced using white glaze,
20 parts by weight of a powder composed of titanium oxide-coated particles shown below (: titanium oxide-coated particle powder) was added and mixed to prepare enamel glaze A.

(Titanium oxide coated particle powder) Powder composed of titanium oxide coated particles in which the surface of thin mica particles is coated with titanium oxide Particle size: 10 to 60 μm Average particle size: 19 μm TiO ₂ coverage (content ): 30% The above particle size is measured by a laser diffraction type particle size distribution analyzer, and the average particle size indicates a 50% cumulative particle size.

Next, the underglaze enamel obtained above was glazed on the surface of a steel plate as a substrate (metal substrate) of a reflection screen by a spray method, and then baked at 800 ° C. to form a base enamel layer on the steel plate surface. Was formed. In addition, as a steel sheet, the carbon content is
A nickel-plated steel sheet treated by immersing a very low carbon steel sheet of 50 mass-ppm in a nickel sulfate aqueous solution was used.

Next, on the base enamel layer obtained above,
The enamel glaze A obtained above was glazed by a spray method and then fired at 750 ° C. (Example 1) or 755 ° C. (Example 2). A surface enamel layer having the composition and the content of the titanium oxide-coated particles was formed, and a sample of a reflection screen was produced as a trial. Next, the reflection luminance, glossiness, surface roughness of the surface enamel layer: Ra (arithmetic mean roughness) and Mohs hardness of the obtained reflection screen sample were measured.

Further, an image was evaluated by a liquid crystal projector. FIG. 1 shows the measurement results of the reflection luminance of the reflection screen of the present invention in comparison with the reflection luminance of a conventional diffuse reflection screen (made of PVC) and a retroreflective screen (made of PVC coated with glass beads). Table 3 shows the evaluation results of the image of the reflection screen of the present invention in comparison with the conventional diffuse reflection screen and the regression reflection screen.

Table 4 shows the results of measurement of the surface roughness of the surface enamel layer of the reflection screen of the present invention: Ra, gloss: Gs (45 °), and Mohs hardness. As shown in FIG. 1, the reflective screen of the present invention has a wide viewing angle and excellent sharpness,
It turned out that it has sufficient reflection luminance. Further, as shown in Table 3, it was found that the reflective screen of the present invention was very easy to see even in a place where the image was clear and bright at a wide viewing angle, and there was little halation.

Further, as shown in Table 4, the reflective screen of the present invention has a surface hardness (Mohs hardness ≧ 4) which is not available in the conventional reflective screen, and is excellent in scratch resistance and impact resistance. Do you get it. Further, FIG. 1, Table 3 and Table 4
As shown in Example 1, by giving a predetermined surface roughness (: Ra ≧ 2.5 μm) to the surface of the surface enamel layer, a particularly wide viewing angle can be obtained and halation can be suppressed very effectively. I knew I could do it.

[Example 3] (Reflection screen with improved sharpness / erasability function using cold rolled steel base material): SiO ₂ glaze: 100 parts by weight, clay: 5 parts by weight, silica powder:
10 parts by weight, borax: 0.4 parts by weight, sodium nitrite: 0.15 parts by weight, and water: 47 parts by weight are charged into a ball mill, mixed, pulverized, and a mud (: slip) (under an enamel) Glaze).

Further, 80 parts by weight of white glaze (frit for enamel) having the composition shown in Table 1, 20 parts by weight of transparent glaze (frit for enamel) having the composition shown in Table 1, 5 parts by weight of clay, potassium chloride : 0.20 parts by weight and 50 parts by weight of water were charged into a ball mill, mixed and pulverized to prepare a mud (: slip). Next, for the slip prepared using a white glaze and a transparent glaze: 100 parts by weight (in terms of weight after firing), a powder composed of the following titanium oxide-coated particles (: titanium oxide-coated particle powder) PA and PB
Was added and mixed in an amount of 10.5 parts by weight and 10.5 parts by weight, respectively, to prepare enamel glaze B.

(Titanium oxide-coated particle powder) Powder composed of titanium oxide-coated particles having titanium oxide coated on the surface of lamellar mica particles (powder PA;) Particle size: 10 to 60 μm Average particle size: 19 μm TiO ₂ Coverage (content): 30% (powder PB;) Particle size: 5 to 25 μm Average particle size: 11 μm TiO ₂ coverage (content): 38% The above particle size is measured by laser diffraction particle size distribution measurement. The average particle size is measured by an apparatus, and indicates the 50% cumulative particle size.

Next, the underglaze enamel obtained above was glazed on the surface of a steel plate as a substrate (metal substrate) of a reflection screen by a spray method, and then baked at 800 ° C. to form a base enamel layer on the surface of the steel plate. Was formed. Note that, as the steel sheet, the same nickel-plated ultra-low carbon steel sheet as in Examples 1 and 2 was used.

Next, on the base enamel layer obtained above,
The enamel glaze B obtained above was glazed by a spray method, and then baked at 760 ° C. to form a surface enamel layer having a thickness of 70 μm and a composition shown in Table 5 and a content of titanium oxide-coated particles on the outer surface of the steel sheet. Formed and prototyped reflective screen samples.
Next, the reflection luminance of the obtained reflection screen sample,
Gloss, surface roughness of surface enamel layer: Ra (arithmetic mean roughness),
The Mohs hardness and the erasability (required number of erasures) of the writing marker were measured.

Further, an image was evaluated by a liquid crystal projector. FIG. 2 shows the measurement results of the reflection luminance of the reflection screen of the present invention in comparison with the reflection luminance of a conventional diffuse reflection screen (made of PVC) and a retroreflective screen (made of PVC coated with glass beads). Table 6 shows the evaluation results of the image of the reflective screen of the present invention and the erasability of the drawing marker in comparison with the conventional diffuse reflection screen and the regression reflection screen.

Table 7 shows the measurement results of the surface roughness of the surface enamel layer of the reflection screen of the present invention: Ra, gloss: Gs (45 °), and Mohs hardness. As shown in FIG. 2 and Table 6, the reflective screen of the present invention has an excellent erasability function, can suppress the occurrence of halation, is excellent in sharpness at a wide viewing angle, and has a sufficient reflection luminance. And the image was found to be a clear reflective screen.

Further, as shown in Table 7, the reflective screen of the present invention has a surface hardness (Mohs hardness ≧ 4) which is not available in the conventional reflective screen, and is excellent in scratch resistance and impact resistance. Do you get it. [Example 4] (Reflection screen with improved clarity / diffuse reflection function using aluminum-plated steel sheet as base material): Phosphoric acid glaze (frit for enamel) having composition shown in Table 8: 100 parts by weight of nitric acid A blending material containing 0.20 parts by weight of soda, 30 parts by weight of titanium oxide (TiO ₂ , white pigment) and 50 parts by weight of water is put into a ball mill, mixed and pulverized to produce a muddy substance (: slip). did.

Next, with respect to 100 parts by weight (in terms of weight after firing) of the above slip produced using a phosphoric acid glaze and a white pigment, the same titanium oxide used in Examples 1 and 2 was used. 20 parts by weight of a powder composed of coated particles (: titanium oxide-coated particle powder) was added and mixed to prepare enamel glaze C. Next, the enamel glaze C obtained above is
The surface of an aluminum-plated steel plate, which is the substrate (metal substrate) of the reflection screen, is glazed by a spray method and then fired at 525 ° C., and the outer surface of the steel plate has a thickness of 40 μm and a composition shown in Table 9 and particles coated with titanium oxide. A surface enamel layer having a content was formed, and a sample of a reflection screen was prototyped.

Next, the glossiness of the sample of the obtained reflection screen and the surface roughness of the surface enamel layer: Ra (arithmetic mean roughness)
And Mohs hardness were measured. In addition, an image was evaluated by a liquid crystal projector. Tables 10 and 11 show the evaluation results of the image of the reflective screen of the present invention, and the surface roughness of the surface enamel layer of the reflective screen of the present invention: Ra, and the glossiness: Gs.
(45 °) shows the measurement results of Mohs hardness.

As shown in Table 10, it was found that the reflection screen of the present invention was very easy to see even in a place where the image was clear and bright at a wide viewing angle, and almost no halation was observed. Further, as shown in Table 11, it was found that the reflection screen of the present invention had a surface hardness (Mohs hardness ≧ 4) that was not found in the conventional reflection screen, and was excellent in scratch resistance and impact resistance.

[Example 5] (Reflection screen with improved clarity / erasability function using aluminum-plated steel sheet as base material): Phosphoric acid glaze (frit for enamel) having composition shown in Table 8: 90 parts by weight , A transparent glaze (frit for enamel) having the composition shown in Table 1: 10 parts by weight, sodium nitrate: 0.20 part by weight, titanium oxide (TiO ₂ , white pigment): 30 parts by weight, and water: 50 parts by weight. Was put into a ball mill, mixed and pulverized to prepare a mud (: slip).

Next, the same titanium oxide coating as used in Example 3 was applied to 100 parts by weight (in terms of weight after firing) of the above slip produced using a phosphoric acid glaze, a transparent glaze and a white pigment. Powder composed of particles (: titanium oxide-coated particle powder) 10.5 parts by weight of PA and 10.5 parts by weight of PB
0.5 part by weight was added and mixed to prepare enamel glaze D. Next, the enamel glaze D obtained above was glazed on the surface of an aluminum-plated steel plate as a substrate (metal substrate) of the reflection screen by a spray method, and then baked at 525 ° C. to form a film on the outer surface of the steel plate. A surface enamel layer having a thickness: 40 μm and a composition shown in Table 12 and a content of titanium oxide-coated particles was formed, and a sample of a reflection screen was prototyped.

Next, the glossiness of the sample of the obtained reflection screen, the surface roughness of the surface enamel layer: Ra (arithmetic mean roughness), Mohs hardness, and the erasability of the drawing marker (required number of erasures) were measured. . In addition, an image was evaluated by a liquid crystal projector. Tables 13 and 14 show the evaluation results of the image of the reflective screen of the present invention, the erasability of the drawing marker, and the surface roughness of the surface enamel layer of the reflective screen of the present invention: R
a, Gloss: The measurement results of Gs (45 °) and Mohs hardness are shown.

As shown in Table 13, the reflective screen of the present invention has an excellent erasability function and can suppress the occurrence of halation. It turned out to be a screen. Further, as shown in Table 14, it was found that the reflective screen of the present invention had a surface hardness (Mohs hardness ≧ 4) not found in the conventional reflective screen, and was excellent in scratch resistance and impact resistance.

[Example 6] (Reflection screen with improved sharpness / diffuse reflection function using Zn-Al alloy-plated steel sheet as a base material): In the above-mentioned Example 4, the substrate of the reflection screen (metal base material) As the Zn-Al alloy plated steel sheet, the aluminum content of the Zn-Al alloy plating layer is 55%, the Si content is 1.6%, and the balance is Zn and unavoidable impurities.
Example 4 except that the firing temperature of the surface enamel layer was 510 ° C.
A sample of a reflective screen was prototyped under the same method and conditions as described above.

Next, in the same manner as in Embodiment 4 described above,
The performance of the obtained reflection screen was evaluated. Table 15, Table 16
Shows the obtained evaluation results. As shown in Table 15,
It was found that the reflective screen of the present invention was very easy to see even in a place where the image was clear and bright at a wide viewing angle, and almost no halation was observed.

Further, as shown in Table 16, the reflective screen of the present invention has a surface hardness (Mohs hardness ≧ 4) not found in the conventional reflective screen, and is excellent in scratch resistance and impact resistance. Do you get it. [Example 7] (Reflection screen with improved sharpness / erasability function using Zn-Al alloy-plated steel sheet as a base material): In Example 5, Zn-Al alloy-plated steel sheet was used as a substrate (metal base material) of the reflection screen. Aluminum content in Al alloy plating layer is 55
%, The content of Si is 1.6%, the balance is Zn and Zn-Al alloy plated steel which is an unavoidable impurity, and the method and conditions are the same as in Example 5 except that the firing temperature of the surface enamel layer is 510 ° C. Made a sample of a reflective screen.

Next, in the same manner as in the fifth embodiment,
The performance of the obtained reflection screen was evaluated. Table 17, Table 18
Shows the obtained evaluation results. As shown in Table 17,
The reflective screen of the present invention was found to be excellent in the erasing function and capable of suppressing the occurrence of halation, and was found to be a highly visible reflective screen with a wide viewing angle and a clear and bright image.

Further, as shown in Table 18, the reflective screen of the present invention has a surface hardness (Mohs hardness ≧ 4) not found in the conventional reflective screen, and is excellent in scratch resistance and impact resistance. Do you get it. As described above, according to the present invention, according to the present invention, an aluminum-plated steel sheet or a Zn-Al alloy-plated steel sheet is used as a metal substrate, and as shown in the above-described Examples 4 to 7, a single enamel layer (surface Enamel layer)
By having the excellent performance described above,
In addition, it has become possible to obtain a reflective screen which is lightweight and easy to handle.

[0135]

[Table 1]

[0136]

[Table 2]

[0137]

[Table 3]

[0138]

[Table 4]

[0139]

[Table 5]

[0140]

[Table 6]

[0141]

[Table 7]

[0142]

[Table 8]

[0143]

[Table 9]

[0144]

[Table 10]

[0145]

[Table 11]

[0146]

[Table 12]

[0147]

[Table 13]

[0148]

[Table 14]

[0149]

[Table 15]

[0150]

[Table 16]

[0151]

[Table 17]

[0152]

[Table 18]

[0153]

According to the present invention, a clear image can be obtained with a wide viewing angle, there is little halation, and writing and erasing with a marker or the like are possible, handling is easy, and reflection is excellent in workability. It has become possible to provide a screen and a method for manufacturing the screen.

[Brief description of the drawings]

FIG. 1 is a graph showing a measurement result of a reflection luminance of a reflection screen.

FIG. 2 is a graph showing a measurement result of a reflection luminance of a reflection screen.

FIG. 3 is an explanatory view (perspective view) showing a method of measuring reflected luminance.

FIG. 4 is an explanatory view (side view) showing the reflection characteristics of the reflection screen.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 Incident light 2 Reflected light 3 Reflective screen 3 Sample of _S reflective screen 4 Beads 10 Light source 11 Luminance meter

 ──────────────────────────────────────────────────続 き Continued on front page F term (reference) 2H021 BA02 BA05 BA10 2H042 BA02 BA14 BA15 BA19 DA10 2H088 EA12 HA10 HA21 MA07 5C058 EA02 EA33

Claims (12)

[Claims] 1. A reflective screen having a surface enamel layer containing titanium oxide-coated particles and white glaze on an outer surface of a metal substrate. 2. The reflection screen according to claim 1, wherein the surface enamel layer has a surface roughness Ra (arithmetic average roughness) of 2.5 μm or more. 3. The surface enamel layer has a surface roughness Ra (arithmetic mean roughness) of 1.5 μm or more and less than 2.5 μm, and a glossiness of Gs.
The reflective screen according to claim 1, wherein (45 °) is 15 to 25%. 4. The reflection screen according to claim 3, wherein the surface enamel layer further contains a transparent glaze. 5. The reflection screen according to claim 1, wherein the titanium oxide-coated particles are particles in which the surface of mica particles is coated with titanium oxide. 6. An enamel glaze coated on the surface of a cold-rolled steel sheet and then fired, and the surface of the resulting enamel layer is coated on a surface of an enamel containing a powder composed of titanium oxide-coated particles and a white glaze. And then baking at 700 to 850 ° C. 7. An aluminum-plated steel sheet or Zn-Al
A method of manufacturing a reflection screen, comprising applying a powder composed of titanium oxide-coated particles and a glaze on an enamel containing a white glaze to the surface of an alloy-plated steel sheet, followed by firing at 400 to 600 ° C. 8. The above-mentioned enamel glaze is obtained by adding a powder composed of titanium oxide-coated particles to a mud obtained by pulverizing a mixture of enamel frit containing white glaze and water,
8. The method for producing a reflective screen according to claim 6, wherein the enamel is an enamel glaze obtained by mixing. 9. An enamel glaze is applied to the surface of a cold-rolled steel sheet and then fired, and the surface of the base enamel layer obtained is composed of titanium oxide-coated particles, each having a different average particle diameter. A method of manufacturing a reflective screen, comprising applying an enamel glaze containing at least two kinds of powders, a white glaze, and further a transparent glaze, and thereafter firing at 700 to 850 ° C. 10. An aluminum-plated steel sheet or Zn-
On the surface of an Al alloy-plated steel sheet, a glaze on enamel containing at least two types of powder, each composed of titanium oxide-coated particles, each having a different average particle size, a white glaze, or a transparent glaze is applied. And then 400-600
B. 11. The above-mentioned enamel glaze is formed of titanium oxide-coated particles, both in a white glaze or in a slurry obtained by pulverizing a mixture of enamel frit containing a transparent glaze and water. 11. The method for producing a reflective screen according to claim 9, wherein the glaze is obtained by adding and mixing at least two kinds of powders having different average particle diameters. 12. The method of manufacturing a reflection screen according to claim 6, wherein said titanium oxide-coated particles are particles having a surface coated with titanium oxide on mica particles.