Composite material

FIELD OF THE INVENTION

P-0001[0001] The present invention relates to a composite material which is adapted to produce a photocatalytic coating onto a base material surface, wherein a decomposition/removal action of dirt which is adhered to the surface thereof is carried out, a photocatalytic effect such as hydrophilicity is caused to be generated, and a surface reflection or an interference color is suppressed.

BACKGROUND OF THE INVENTION

P-0002[0002] A technology, in which a photocatalytic coating is produced onto a base material surface, decomposition/removal of dirt adhering to the surface thereof etc. is carried out, and this surface is made to be hydrophilic has been conventionally known. For example, a technology, wherein photocatalyst coating is produced onto a base material surface and decomposition removal of dirt adhering to the surface thereof is carried out, is disclosed in JP-A-63-100042. A technology of forming a photocatalyst film on a base material surface, forming a porous inorganic oxide film as the outermost surface film thereon, making the surface of the porous inorganic oxide film hydrophilic, and also carrying out decomposition/removal of the dirt adhering to the surface of the porous inorganic oxide film on a photocatalyst film of a lower film so as to maintain the hydrophilicity of the porous inorganic oxide film of the outermost surface film, is disclosed in JP-A-10-36144, and JP-A-2000-53449. A technology of forming a photocatalyst film on a base material surface, making the base material surface hydrophilic by use of a hydrophilicity of photocatalyst itself, is disclosed in WO96 29375 International Publication. A technology of forming a photocatalyst film on the surface of EC (electrochromic) element, forming a porous inorganic oxide film as the outermost surface thereon and acquiring hydrophilicity in a porous inorganic oxide film of the outermost surface, wherein along with this, decomposition removal of the dirt adhering to the surface of the porous inorganic oxide film is carried out on a photocatalyst film of a lower film so as to maintain a hydrophilicity of the porous inorganic oxide film of the outermost surface, and further ultraviolet rays are intercepted on a photocatalyst film so as to obviate a degradation of EC substance, is disclosed in JP-A-2000-155344.

P-0003[0003] In order to have a photocatalytic effect (a decomposition effect of an accretion and a hydrophilic effect), about 100 nm thickness of a photocatalyst film is required. However, if there is about 100 nm thickness of a photocatalyst film, when photocatalyst material with high refractive index, such as TiO₂, is used, reflection on the photocatalyst film is large, and an interference color arises strongly. For this reason, when it is applied to mirrors such as an exterior mirror for automobiles, double image might be produced or an obstructive interference color might be produced. Especially in EC elements, this interference color overlaps with coloring of the EC elements itself, and might produce a strange color tone.

P-0004[0004] This invention is intended to overcome the aforementioned problems in the related arts, and provide composite materials which control surface reflection or an interference color, securing the photocatalytic effect simultaneously.

SUMMARY OF THE INVENTION

P-0005[0005] According to this invention, a composite material having a laminated film in which between two or more photocatalyst layers each possessing a light permeability and an a photocatalytic reactivity, middle layers composed of a light permeable material having a reflectance different from that of the photocatalyst layers are interposed, provided on the surface of a substrate. According to this structure, since a photocatalytic effect added to the photocatalytic effect by each photocatalyst film is obtained, even if each photocatalyst film is thin, a strong photocatalytic effect can be produced. What is more, since each photocatalyst film can be made thin, surface reflection and an interference color can be stopped. Pluralities of photocatalyst films can comprise, for example, the same photocatalyst material. When the middle layers comprise pluralities of layers, these pluralities of middle layers can comprise the same material. The middle layers can comprise a material with a refractive index lower than for example a photocatalyst film. Incidentally, this invention also allows an arrangement of a proper functional film disposed on an uppermost layer of the photocatalyst film, or between the lowermost layer of photocatalyst film and the base material surface, as needed.

P-0006[0006] In this invention, thickness of each photocatalyst film can be set to, for example, 50 nm or less (preferably 30 nm or less), whereby a surface reflection and an interference color can be suppressed effectively. Also, thickness of this respective photocatalyst film can be set to, for example, 5 nm or more (preferably 10 nm or more), whereby a sufficient photocatalytic effect can be obtained, controlling the increase of the number of films of a photocatalyst film simultaneously. Moreover, the thickness of a single film or multiple middle layers can be set to, for example, 50 nm or less (more preferably 30 nm or less), whereby, the photocatalytic effect of each photocatalyst film can be added and obtained easily on the outermost surface of a laminated film, and the surface reflection and the interference color by the middle layer itself can be controlled effectively. Also, thickness of the single or multiple middle layers, for example, can be set to as 5 nm or more (preferably 10 nm or more); whereby an effect (a surface reflective control effect, an interference color control effect) of dividing photocatalyst films into pluralities of films becomes easy to be obtained. The photocatalyst films can be composed of such a material as TiO₂, SrTiO₃, and WO₃. Moreover, the aforementioned middle layer can be composed of an inorganic oxide such as SiO₂, WO₃, Al₂O₃, and ITO, and other oxides. The middle layer can also be composed of another photocatalyst material with a different refractive index from the aforementioned photocatalyst films.

P-0007[0007] According to this invention, the laminated film has a hydrophilic film having an optical permeability structured with different materials from the photocatalyst film of said uppermost layer (e.g., that having a refractive index lower than the photocatalyst film of the uppermost layer) provided on said photocatalyst film, and said hydrophilic film constitutes the outermost surface of the laminated film so as to be exposed to an open air. According to this structure, the surface can be made into hydrophilicity (or have an increased hydrophilicity). Alternatively, a photocatalyst film which constitutes an uppermost surface of said multiple layers may constitute the outermost surface of said laminated film so as to be exposed to an open air. According to this structure, the decomposition effect of the accretion by the photocatalyst film is obtained, and also the hydrophilic effect by the photocatalyst film itself is expectable. Thickness of the hydrophilic film can be set to, for example, 50 nm or less (more preferably 30 nm or less) as similar to the middle layer. According to this structure, the photocatalytic effect of each photocatalyst film becomes easy to be added on the outermost surface of laminated film, and also the surface reflection and the interference color by this hydrophilic film itself can be suppressed effectively. Moreover, thickness of the hydrophilic film can be set to 5 nm or more (more preferably 10 nm or more). Consequently, abrasion resistance of the hydrophilic film can be made good.

P-0008[0008] According to this invention, the outermost surface (exposure side to an open air) of the laminated film can be formed in a state of porosity. This makes it possible to make the surface into hydrophilicity (or to be the surface having an increased hydrophilicity).

P-0009[0009] In this invention, the aforementioned base material can be constituted, e.g., by a transparent substrate. By employment of this transparent substrate, it can be adapted for a wide range of uses such as the windowpanes for vehicles and construction, etc., the lens for glasses, the lens for cameras, and a filter for cameras, etc. In this case, the aforementioned laminated film can be formed on one side or both sides of a transparent substrate. Also, if the aforementioned laminated film is formed on one side of the transparent substrate and a reflective film is formed on the backside of this transparent substrate, the mirror main part of the exterior mirror for automobiles and other mirrors can be obtained.

P-0010[0010] In this invention an EC element can be constituted by carrying out opposing arrangement of the second substrate on the backside of the transparent substrate, or by putting a substance which exhibits an electrochromic phenomenon between these substrates. By employment of this structure, since the thickness of each photocatalyst film required to produce a photocatalytic effect is thin, surface reflection and an interference color can be stopped. Accordingly, original color tone of EC elements is obtained. If the aforementioned second substrate is structured with a transparent substrate and a reflective film is formed in the external surface side of this second substrate, EC mirror can be constituted. EC mirror can be used as a mirror main part of EC exterior mirror for automobiles, for example.

BRIEF DESCRIPTION OF THE DRAWINGS

P-0011[0011]FIG. 1 is a cross-sectional view showing the exemplary embodiment of this invention.

P-0012[0012]FIG. 2 is a cross-sectional view schematically showing a conventional structure of two-layer laminated film.

P-0013[0013]FIG. 3 is a view showing spectral reflectance characteristics measured about a sample having a structure of FIG. 1.

P-0014[0014]FIG. 4 is a view showing spectral reflectance characteristics measured about a sample having a structure of FIG. 2.

P-0015[0015]FIG. 5 is a cross-sectional view schematically showing an exemplary embodiment of a mirror using a structure of FIG. 1.

P-0016[0016]FIG. 6 is a cross-sectional view schematically showing an exemplary embodiment of a mirror main part of EC exterior mirror for automobiles using a structure of FIG. 1.

P-0017[0017]FIG. 7 is a cross-sectional view schematically showing a mirror main part of EC exterior mirror for automobiles having no laminated film on the surface of a glass substrate.

P-0018[0018]FIG. 8 is a cross-sectional view schematically showing a mirror main part of EC exterior mirror for automobiles having two-layer laminated film on the surface of a glass substrate.

P-0019[0019]FIG. 9 is a view showing spectral reflectance characteristics, respectively measured about samples of FIG. 7 and FIG. 8 in anti-glare state.

P-0020[0020]FIG. 10 is a view showing spectral reflectance characteristics, respectively measured about samples of FIG. 6 and FIG. 7 in anti-glare state.

P-0021[0021]FIG. 11 is a cross-sectional view schematically showing other embodiment of a mirror main part of EC exterior mirror for automobiles using a structure of FIG. 1.

P-0022[0022]FIG. 12 is a cross-sectional view schematically showing other embodiment of a mirror main part of EC exterior mirror for automobiles using a structure of FIG. 1.

P-0023[0023]FIG. 13 is a cross-sectional view schematically showing other embodiment of a mirror main part of EC exterior mirror using a structure of FIG. 1.

P-0024[0024]FIG. 14 is a cross-sectional view schematically showing other embodiment of a mirror main part of EC exterior mirror for automobiles using a structure of FIG. 1.

P-0025[0025]FIG. 15 is a cross-sectional view schematically showing EC elements structured transparently in whole part using a structure of FIG. 1.

P-0026[0026]FIG. 16 is a cross-sectional view schematically showing other embodiment of EC elements structured transparently in whole part using a structure of FIG. 1.

P-0027[0027]FIG. 17 is a cross-sectional view schematically showing other embodiment of EC elements structured transparently in whole part using a structure of FIG. 1.

P-0028[0028]FIG. 18 is a cross-sectional view schematically showing other embodiment of EC elements structured transparently in whole part using a structure of FIG. 1.

PREFERRED EMBODIMENTS OF THE INVENTION

P-0029[0029] Embodiments of this invention will be shown in cross-sectional view in FIG. 1. Composite material <b>10</b> comprises a laminated film <b>18</b>, which is laminated on one side of transparent substrate (transparent base material) <b>12</b> structured with glass or a synthetic resin, such as acrylic resin. The laminated film <b>18</b> is formed in such a manner that photocatalyst films <b>14</b> (<b>14</b>-<b>1</b>, <b>14</b>-<b>2</b>, - - - , <b>14</b>-<i>n</i>) each comprising a photocatalyst material with a light permeability property, and middle layers <b>16</b> (<b>16</b>-<b>1</b>, <b>16</b>-<b>2</b>, - - - , <b>16</b>-<i>n</i>−1) structured with a material with a light permeability property, having a different refractive index from the photocatalyst films (for example, a refractive index is lower than this photocatalyst material), are laminated alternately. Further, hydrophilic film <b>17</b> having a light permeability property, comprises a different material from photocatalyst film <b>14</b>-<i>n </i>of this uppermost film (for example, the same material as the middle layer <b>16</b>) is laminated on the photocatalyst film <b>14</b>-<i>n </i>of the uppermost film so as to present a transparent whole constitution. The hydrophilic film <b>17</b> which constitutes the outermost surface (exposure side to an open air) of the laminated film <b>18</b> is constituted in a state of porosity having fine unevenness formed on the surface thereof. As for the middle layers <b>16</b>-<b>1</b>, <b>16</b>-<b>2</b>, - - - , and <b>16</b>-<i>n</i>−1, either in porous state or in non-porous state, the photocatalytic effect added to each photocatalyst film <b>14</b> is obtained on the outermost surface of the laminated film <b>18</b>. Using a PVD method such as vacuum vapor deposition and sputtering, or any other film formation method, the laminated film <b>18</b> is formed by laminating each film one by one on the transparent substrate <b>12</b>. As for hydrophilic film <b>17</b>, by setting film formation conditions of a PVD method such as vacuum vapor deposition or sputtering, in porous state, film formation in porous state with fine unevenness formed on the surface was achieved in a similar manner to a method disclosed in JP-A-10-36144 and JP-A-2000-53449, which are incorporated herein by references.

P-0030[0030] As a photocatalyst material of the photocatalyst films <b>14</b>, TiO₂, SrTiO₃, and WO₃etc. can be used, for example. As a material of middle layers <b>16</b>, inorganic oxides such as SiO₂, WO₃, Al₂O₃, and ITO, etc. can be used, for example. As a material of the porous hydrophilic film <b>17</b>, the same material as the middle layers <b>16</b> can be used, for example, inorganic oxides, such as SiO₂, WO₃, Al₂O₃, and ITO, etc. can be used. Referring to the film thickness of each photocatalyst film <b>14</b> respectively, since surface reflection becomes high and an interference color arises again if too thick, 50 nm or less (preferably 30 nm or less) is suitable. Also, if film thickness of each photocatalyst film <b>14</b> is too thin, since its number of films required to obtain sufficient photocatalytic effect will increase, 5 nm or more (preferably 10 nm or more) is suitable. Also, if the film thickness of each middle layer <b>16</b> is too thick, the photocatalytic effect added to each photocatalyst film <b>14</b> is hard to be obtained on the outermost surface of the laminated film. Moreover, since the surface reflection by the middle layer itself becomes high and an interference color arises again, 50 nm or less (preferably 30 nm or less) are suitable respectively. Moreover, if thickness of each middle layer <b>16</b> is too thin, since the effect (the surface reflective control effect, the interference color control effect) of dividing a photocatalyst films into plurality of films is hard to be obtained, 5 nm or more (preferably 10 nm or more) is suitable. Moreover, referring to the thickness of hydrophilic film <b>17</b>, if too thin, since abrasion resistance falls, 5 nm or more (preferably 10 nm or more) is suitable. Referring to the number of the laminated film <b>18</b>, since the number of films is increased the number of processes is increased correspondingly, incurring a high manufacture cost and coloration by the color of the film itself, films of about eighteen layers or less are suitable. About 400 nm or less is suitable for the thickness of the whole laminated film <b>18</b>.

P-0031[0031] An example of a setting of the thickness and the number of laminated in the case where photocatalyst film <b>14</b> is composed of TiO₂, and middle layers <b>16</b> and the porous hydrophilic film <b>17</b> are composed of SiO₂is shown in Table 1. Incidentally, in Table 1 the number of laminating “the middle layers and a hydrophilic film” shows a total number of these both films. <tables id="TABLE-US-00001" num="1"><table frame="none" colsep="0" rowsep="0"><tgroup align="left" colsep="0" rowsep="0" cols="3"><colspec colname="OFFSET" colwidth="56PT" align="left" /><colspec colname="1" colwidth="84PT" align="center" /><colspec colname="2" colwidth="77PT" align="center" /><thead><row><entry /><entry namest="OFFSET" nameend="2" align="center">TABLE 1</entry></row></thead><tbody valign="top"><row><entry /><entry /></row><row><entry /><entry namest="OFFSET" nameend="2" align="center" rowsep="1" /></row><row><entry /><entry>Photocatalyst Layer</entry><entry>Middle Layer and</entry></row><row><entry /><entry>(TiO₂)</entry><entry>Hydrophilic Layer (SiO₂)</entry></row></tbody></tgroup><tgroup align="left" colsep="0" rowsep="0" cols="5"><colspec colname="OFFSET" colwidth="56PT" align="left" /><colspec colname="1" colwidth="35PT" align="center" /><colspec colname="2" colwidth="49PT" align="center" /><colspec colname="3" colwidth="35PT" align="center" /><colspec colname="4" colwidth="42PT" align="center" /><tbody valign="top"><row><entry /><entry /><entry>No. of</entry><entry /><entry>No. of</entry></row><row><entry /><entry>Thickness</entry><entry>Lamination</entry><entry>Thickness</entry><entry>Lamination</entry></row><row><entry /><entry namest="OFFSET" nameend="4" align="center" rowsep="1" /></row></tbody></tgroup><tgroup align="left" colsep="0" rowsep="0" cols="5"><colspec colname="1" colwidth="56PT" align="center" /><colspec colname="2" colwidth="35PT" align="center" /><colspec colname="3" colwidth="49PT" align="center" /><colspec colname="4" colwidth="35PT" align="center" /><colspec colname="5" colwidth="42PT" align="center" /><tbody valign="top"><row><entry>Set Example 1</entry><entry>10 nm</entry><entry>9</entry><entry>10 nm</entry><entry>9</entry></row><row><entry>Set Example 2</entry><entry>10 nm</entry><entry>8</entry><entry>10 nm</entry><entry>8</entry></row><row><entry>Set Example 3</entry><entry>10 nm</entry><entry>7</entry><entry>10 nm</entry><entry>7</entry></row><row><entry>Set Example 4</entry><entry>15 nm</entry><entry>6</entry><entry>10 nm</entry><entry>6</entry></row><row><entry>Set Example 5</entry><entry>20 nm</entry><entry>5</entry><entry>10 nm</entry><entry>5</entry></row><row><entry>Set Example 6</entry><entry>20 nm</entry><entry>4</entry><entry>10 nm</entry><entry>4</entry></row><row><entry namest="1" nameend="5" align="center" rowsep="1" /></row></tbody></tgroup></table></tables>

P-0032[0032] Referring to composite material <b>10</b> as shown in FIG. 1, transparent substrate <b>12</b> is composed of glass substrate, and the surface thereof is laminated by eight layers of TiO₂for every 10 nm thickness as photocatalyst films <b>14</b>, and eight layers of SiO₂with lower refractive index than TiO₂for every 10 nm as middle layers <b>16</b> or porous hydrophilic film <b>17</b>, were laminated alternately. A sample structured transparently in whole part was thus fabricated, and similarly characteristics were measured. A measurement result will be shown below.

P-0033[0033] (1) Spectral Reflectance Characteristics:

P-0034[0034] Spectral reflectance characteristics measured concerning a sample of this invention will be shown in FIG. 3. Similarly, the spectral reflectance characteristics measured concerning the conventionally structured sample (Photocatalyst film <b>14</b>A:100 nm thickness, porous hydrophilic film <b>17</b>A:10 nm thickness) will be shown in FIG. 4. When FIG. 3 and FIG. 4 are contrasted, it is elucidated that according to the sample of this invention, reflectance is low in a whole visible region compared with a conventionally structured sample, the spectral characteristic is flat and an interference color is stopped.

P-0035[0035] (2) Photocatalyst Characteristic:

P-0036[0036] Referring to a sample of conventional constitution, Table 2 shows a time-lapse change of a water-drip contact angle (hydrophilic ability) at the time of setting thickness of porous hydrophilic film <b>17</b>A as about 10 nm, and setting thickness of TiO₂film <b>14</b>A variously. “initial water-drip contact angle” is a value immediately after manufacture,” “six months after water-drip contact angle” is a value obtained after cleaning and waxing a car continuously for six months. <tables id="TABLE-US-00002" num="2"><table frame="none" colsep="0" rowsep="0"><tgroup align="left" colsep="0" rowsep="0" cols="3"><colspec colname="1" colwidth="84PT" align="center" /><colspec colname="2" colwidth="126PT" align="center" /><colspec colname="3" colwidth="7PT" align="left" /><thead><row><entry namest="1" nameend="3" align="center">TABLE 2</entry></row></thead><tbody valign="top"><row><entry /></row><row><entry namest="1" nameend="3" align="center" rowsep="1" /></row><row><entry>Thickness of TiO₂</entry><entry>Water-drip Contact Angle</entry><entry /></row></tbody></tgroup><tgroup align="left" colsep="0" rowsep="0" cols="3"><colspec colname="1" colwidth="84PT" align="center" /><colspec colname="2" colwidth="56PT" align="center" /><colspec colname="3" colwidth="77PT" align="center" /><tbody valign="top"><row><entry>Layer</entry><entry>Initial</entry><entry>After 6 months</entry></row><row><entry namest="1" nameend="3" align="center" rowsep="1" /></row><row><entry> 75 nm</entry><entry>Not more than 5</entry><entry>30-40</entry></row><row><entry>100 nm</entry><entry>″</entry><entry>Not more than 20</entry></row><row><entry>150 nm</entry><entry>″</entry><entry>Not more than 10</entry></row><row><entry>200 nm</entry><entry>″</entry><entry>″</entry></row><row><entry>300 nm</entry><entry>″</entry><entry>″</entry></row><row><entry namest="1" nameend="3" align="center" rowsep="1" /></row></tbody></tgroup></table></tables>

P-0037[0037] According to Table 2, it is elucidated that about 100 nm or more of thickness of TiO₂film <b>14</b>A is required in conventionally structured sample, in order to obtain a photocatalyst performance to maintain a water-drip contact angle of 20 degrees or less. On the other hand, when a time-lapse change of a water-drip contact angle was similarly measured about the sample of this invention, an initial water-drip contact angle became 5 degrees or less, and water-drip contact angle became 20 degrees or less six months later. Photocatalyst performance equivalent to the sample of the conventional structure wherein thickness of TiO₂film <b>14</b>A is 100 nm was thus obtained.

P-0038[0038] (3) Abrasion Resistance

P-0039[0039] Referring to the sample of this invention, when the friction test instrument rolled by cloth is made to reciprocate 10,000 times by the load of 1 N/cm²on the sample surface and appearance evaluation was carried out, there was nothing with a crack and sufficient abrasion resistance was obtained.

P-0040[0040] The above results are the results of the measurement for the sample of the setting example 2 of Table 1. However, referring to the sample of other setting examples 1, 3 to 6, spectral reflectance characteristics was obtained, which was low in the whole visible region compared with conventionally structured spectral reflectance characteristics (FIG. 4) of FIG. 2, the spectral characteristic was flat and also an interference color was suppressed. Moreover, referring to photocatalyst characteristic and abrasion resistance also, sufficient characteristic was obtained.

P-0041[0041] Composite material <b>10</b> of the structure as shown in FIG. 1 can be used as the windowpanes for example, for a vehicle, for construction, and the like; the lens for a glass, the lens for a camera; and a filter for a camera, etc. (laminated film <b>18</b> is arranged turning outside). In any case, hydrophilicity and stain-resistance are obtained. Moreover, since surface reflection and an interference color are suppressed, in case of the lens for glasses, a reflective color and a permeation color are not worrisome. Also, in the case of a lens for cameras, and a filter for cameras, the permeation color is suppressed. Whereby, an image cannot be affected easily. In addition, in the case of the windowpanes for vehicles and for construction, etc., the lens for glasses, etc., the laminated films <b>18</b> can also be formed in both sides of transparent substrate <b>12</b> as needed.

P-0042[0042] Also, if a reflective film <b>20</b> composed of such a material as Cr or Al, is formed on the backside of transparent substrate <b>12</b> using the structure of FIG. 1 as shown in FIG. 5, mirror <b>21</b> is constituted. A mirror thus obtained can be adapted to, for example, an exterior mirror for a vehicle or a mirror for a bathroom as mirror main parts. In any case, hydrophilicity and stain-resistance are obtained. Moreover, since surface reflectance is low, a double image is prevented. An interference color is also suppressed. In addition, an outermost surface (open air exposure side) of laminated film <b>18</b> is composed of porous hydrophilic film <b>17</b> in structure as shown in FIG. 1 and FIG. 5. However, photocatalyst film <b>14</b>-<i>n </i>can also be arranged on the outermost surface without constituting the porous hydrophilic film <b>17</b>. Moreover, the photocatalyst film <b>14</b>-<b>1</b> is formed as a first film on the surface of the transparent substrate (transparent base material) <b>12</b>. However, another film can also be arranged between the transparent substrate (transparent base material) <b>12</b> and the photocatalyst film <b>14</b>-<b>1</b>. Also, in each photocatalyst film <b>14</b>-<b>1</b>, <b>14</b>-<b>2</b>, - - - , <b>14</b>-<i>n</i>, all films do not necessarily need to be composed of same photocatalyst materials. Photocatalyst films of different materials may be intermingled. Moreover, the porous hydrophilic film <b>17</b> and the middle layers <b>16</b> do not necessarily need to be composed of same materials, but may be composed of different materials. For example, the porous hydrophilic film <b>17</b> can be structured with porous SiO₂, and the middle layers <b>16</b> can also be composed of materials other than SiO₂(for example, WO₃, Al₂O₃, ITO, etc.). Moreover, each middle layer <b>16</b>-<b>1</b>, <b>16</b>-<b>2</b>, - - - , <b>16</b>-<i>n</i>−1, does not necessarily need to be composed of the same material, and middle layers of different materials may be intermingled.

P-0043[0043] Moreover, an outermost surface of laminated film <b>18</b> can be replaced with a non-hydrophilicity material such as ITO, instead of hydrophilic film <b>17</b>. An uppermost surface of the laminated film <b>18</b> may be composed of a non-hydrophilic material such as ITO, instead of hydrophilic film <b>17</b>. Even if it is non-hydrophilicity material, by arranging a low refractive-index film on the outermost surface, the surface reflectance reduction effect is gained compared with the case wherein a photocatalyst film is arranged on the outermost surface.

P-0044[0044] Also, in a structure of FIG. 1 and FIG. 5, photocatalyst film <b>14</b> is made into three or more (That is, n value is 3 or more) layers, however it may also be composed of two layers (middle layer <b>16</b> arranged between the photocatalyst films <b>14</b> is one layer).

P-0045[0045] In this case, if each thickness of photocatalyst film <b>14</b> to 1 is set as about 50 nm, a sufficient photocatalytic effect can be gained, and along with this, spectral characteristic becomes flat and an interference color is suppressed compared with a photocatalyst film which comprises a single layer with 100 nm thickness. Also, in a structure of FIG. 1, the laminated film is formed only on one side of the transparent substrate <b>12</b>, however, the film can also be formed on both sides. Moreover, in the structure shown in FIG. 1, a transparent substrate (transparent base material) is used to make up the substrate (base material) <b>12</b>, but an opaque material such as the surface of a wall of a building can also be used as the base material. In this case, also surface reflection and an interference color can be suppressed.

P-0046[0046] Embodiment of the mirror main part of EC exterior mirror for a vehicle (anti-glare mirror) using the composite material of this invention will be shown in FIG. 6. Portions of the same designation as those in FIG. 1 are designated the same numerals and signs. Laminated film is formed on one side of transparent substrate <b>12</b> wherein mirror main part <b>22</b> of this EC exterior mirror is structured with glass. Laminated film <b>18</b> is formed by alternatively laminating photocatalyst TiO₂films <b>14</b> (<b>14</b>-<b>1</b>, <b>14</b>-<b>2</b>, - - - , <b>14</b>-<i>n</i>) and SiO₂films <b>16</b> (<b>16</b>-<b>1</b>, <b>16</b>-<b>2</b>, - - - , <b>16</b>-<i>n</i>−1) SiO₂which are composed of SiO₂with a refractive index lower than a photocatalyst TiO₂film, and further laminating porous SiO₂film <b>17</b> is laminated on outermost photocatalyst TiO₂film <b>14</b>-<i>n</i>. The whole part of the resulting laminated film <b>18</b> is transparent. On the backside of glass substrate <b>12</b>, transparent electrode film <b>24</b> such as ITO, EC films <b>25</b> (oxidation coloring film <b>26</b>, such as IrOx, solid electrolyte film <b>28</b> such as Ta₂O₅, and laminates of reduction coloring film <b>30</b> such as WO₃), and an electrode-cum-reflective film <b>32</b> such as Al and Cr, are formed one by one. These laminated films <b>24</b>, <b>25</b>, and <b>32</b> are sealed with sealing agent <b>34</b> such as epoxy and another glass substrates (sealing glass) <b>36</b>. Both edges in the vertical direction of a glass substrate <b>12</b> are equipped with clip electrodes <b>38</b> and <b>40</b>. The clip electrode <b>38</b> is electrically connected to the transparent electrode film <b>24</b>, and the clip electrode <b>40</b> is electrically connected to electrode-cum-reflective film <b>32</b>. By the application of coloring voltage between the clip electrode <b>38</b> and <b>40</b>, the EC films <b>25</b> are colored (anti-glare state) and the EC films <b>25</b> are decolorized by the application of decolorization voltage (non-anti-glare state).

P-0047[0047] As for a mirror main part <b>22</b> of EC exterior mirror of FIG. 6, eight layers of photocatalyst TiO₂layer <b>14</b> for every 10 nm thickness, and eight layers of SiO₂film <b>16</b> and porous SiO2 film <b>17</b> for every 10 nm were laminated alternately, a sample using Al as an electrode-cum-reflective film <b>32</b> was produced, and the reflectance was measured. For comparison, the sample which does not have a laminated film on the surface of glass substrate <b>12</b> shown in FIG. 7, and the sample which has the two-layer laminated film having a photocatalyst TiO₂<b>14</b>A with 180 nm thickness and porous SiO₂<b>17</b>A with 20 nm thickness laminated on the surface of the glass substrate <b>12</b> as shown in FIG. 8 were prepared, and the reflectance was measured similarly. A measurement results will be shown below.

P-0048[0048] Thick line in FIG. 9 indicates reflective characteristic of a sample having two-layer laminated film of FIG. 8 under anti-glare situation, whereas thin line in FIG. 9 indicates spectral reflectance characteristics measured about a sample having no laminated film of FIG. 7 under the anti-glare situation. The sample using the two-layer laminated film shows the characteristic (thick line in FIG. 9) that the optical interference color appeared strongly and overlapped with coloring of EC elements, and exhibits a strange color tone different from the characteristic (thin line in FIG. 9) of the EC elements themselves. Both characteristics are thus compared in order to be clearly elucidated.

P-0049[0049] Table 3 shows a reflectance of a sample with no laminated film of FIG. 7 and that of a sample of FIG. 8 with two layer laminated film measured in anti-glare state and non-anti-glare state. <tables id="TABLE-US-00003" num="3"><table frame="none" colsep="0" rowsep="0"><tgroup align="left" colsep="0" rowsep="0" cols="3"><colspec colname="OFFSET" colwidth="98PT" align="left" /><colspec colname="1" colwidth="98PT" align="center" /><colspec colname="2" colwidth="21PT" align="left" /><thead><row><entry /><entry namest="OFFSET" nameend="2" align="center">TABLE 3</entry></row></thead><tbody valign="top"><row><entry /><entry /></row><row><entry /><entry namest="OFFSET" nameend="2" align="center" rowsep="1" /></row><row><entry /><entry>Reflectance</entry><entry /></row></tbody></tgroup><tgroup align="left" colsep="0" rowsep="0" cols="4"><colspec colname="OFFSET" colwidth="14PT" align="left" /><colspec colname="1" colwidth="84PT" align="left" /><colspec colname="2" colwidth="35PT" align="center" /><colspec colname="3" colwidth="84PT" align="center" /><tbody valign="top"><row><entry /><entry>Sample</entry><entry>Anti-glare</entry><entry>Non-Anti-glare</entry></row><row><entry /><entry namest="OFFSET" nameend="3" align="center" rowsep="1" /></row><row><entry /><entry>FIG. 7: No</entry><entry>10%</entry><entry>60%</entry></row><row><entry /><entry>laminated Film</entry></row><row><entry /><entry>FIG. 8: Two Layer</entry><entry>31%</entry><entry>65%</entry></row><row><entry /><entry>Laminated Film</entry></row><row><entry /><entry namest="OFFSET" nameend="3" align="center" rowsep="1" /></row></tbody></tgroup></table></tables>

P-0050[0050] It can be understood from Table 3 that reflectance of the sample having two layer laminated film has an increased reflectance and a lowered anti-glare function in the anti-glare state as compared with the sample having no laminated film.

P-0051[0051] Thick line of FIG. 10 shows spectral reflectance characteristics of a sample of this invention shown in FIG. 6 measured in anti-glare state. Thin line of FIG. 10 shows spectral reflectance characteristics of a sample with no laminated film shown in FIG. 7 measured in anti-glare state. Comparison of the both characteristics shows a characteristic of a state in this invention where optical interference is suppressed and color tone which is close to a characteristic of EC elements per se (FIG. 10 thin line) is obtained.

P-0052[0052] Table 4 shows a reflectance of a sample with no laminated film of FIG. 7 and that of a sample of this invention of FIG. 6 measured in anti-glare state and non-anti-glare state. <tables id="TABLE-US-00004" num="4"><table frame="none" colsep="0" rowsep="0"><tgroup align="left" colsep="0" rowsep="0" cols="3"><colspec colname="OFFSET" colwidth="98PT" align="left" /><colspec colname="1" colwidth="98PT" align="center" /><colspec colname="2" colwidth="21PT" align="left" /><thead><row><entry /><entry namest="OFFSET" nameend="2" align="center">TABLE 4</entry></row></thead><tbody valign="top"><row><entry /><entry /></row><row><entry /><entry namest="OFFSET" nameend="2" align="center" rowsep="1" /></row><row><entry /><entry>Reflectance</entry><entry /></row></tbody></tgroup><tgroup align="left" colsep="0" rowsep="0" cols="4"><colspec colname="OFFSET" colwidth="14PT" align="left" /><colspec colname="1" colwidth="84PT" align="left" /><colspec colname="2" colwidth="35PT" align="center" /><colspec colname="3" colwidth="84PT" align="center" /><tbody valign="top"><row><entry /><entry>Sample</entry><entry>Anti-glare</entry><entry>Non-Anti-glare</entry></row><row><entry /><entry namest="OFFSET" nameend="3" align="center" rowsep="1" /></row><row><entry /><entry>FIG. 7: No</entry><entry>10%</entry><entry>60%</entry></row><row><entry /><entry>laminated Film</entry></row><row><entry /><entry>FIG. 6: Multilayer</entry><entry>11%</entry><entry>61%</entry></row><row><entry /><entry>Laminated Film</entry></row><row><entry /><entry namest="OFFSET" nameend="3" align="center" rowsep="1" /></row></tbody></tgroup></table></tables>

P-0053[0053] According to FIG. 4, it is elucidated that a sample of this invention is not inferior compared with a sample having no laminated film of FIG. 7 in reflective characteristic. (sufficient anti-glare function is obtained)

P-0054[0054] Other embodiment of the mirror main part of EC exterior mirror for a vehicle using the composite material of this invention will be shown in FIG. 11. Portions of the same designation as those used in FIG. 1 are designated the same numerals and signs. As for mirror main part <b>41</b> of this EC exterior mirror, transparent electrode film <b>42</b> such as ITO, is formed on the backside surface of transparent glass substrate <b>12</b>. Electrode-cum-reflective film <b>46</b> such as Al or Cr, is formed on inner peripheral side of substrate <b>44</b> (which maybe opaque) such as glass arranged in an opposing manner with transparent glass substrate <b>12</b>. Between the transparent glass substrate <b>12</b> and the substrate <b>44</b>, EC solution which constitutes the EC film <b>48</b> (for example, EC substances such as viologen, solvents such as solvents γ-butyrolactone, and propylene carbonate, a mixed solution of ultraviolet-rays absorbents such as benzophenone, and a cyanoacrylate) is incorporated. The EC film <b>48</b> is sealed with sealing agent <b>50</b>. Lower edge of the transparent glass substrate <b>12</b> is equipped with clip electrode <b>52</b>, which is electrically connected to transparent electrode film <b>42</b>. An upper edge of the substrate <b>44</b> is equipped with the clip electrode <b>54</b>, which is electrically connected to an electrode-cum-reflective 46. By the application of coloring voltage between the clip electrode <b>52</b> and <b>54</b>, EC film <b>48</b> is colored (anti-glare state), and the EC film <b>48</b> is decolorized by the application of decolorization voltage (non-anti-glare state).

P-0055[0055] Furthermore, another embodiments of the mirror main part of EC exterior mirror for a vehicle using composite material of this invention are shown in FIG. 12 to FIG. 14, respectively. Portions of the same designation as those in FIG. 1 are designated the same numerals and signs. These mirror main parts of EC exterior mirror for a vehicle are composed of reflective films <b>58</b> such as Al and Cr formed at the backside surface of the transparent glass substrate <b>56</b>. Protection coat <b>59</b> is coated on the backside surface of the reflective film <b>58</b>. As for mirror main part <b>60</b> of EC exterior mirror of FIG. 12, transparent electrode film <b>62</b> and electrode protection film <b>64</b> such as SiO₂are formed in front of transparent glass substrate <b>56</b>, transparent electrode film <b>65</b> and EC substance film <b>66</b> such as WO₃, MoO₃, and IrOx are formed on the backside surface of the transparent glass substrate <b>12</b>, and between both substrates <b>12</b> and <b>56</b>, an electrolyte solution <b>68</b> (for example, an electrolyte such as LiI and LiClO₄, solvents such as γ-butyrolactone, and propylene carbonate, and a mixed solution of ultraviolet absorber such as benzophenone and cyanoacrylate) is incroporated. EC film <b>70</b> (EC substance film <b>66</b> and electrolyte solution <b>68</b>) is sealed with sealing agent <b>72</b>. The lower edge of the transparent glass substrate <b>12</b> is equipped with clip electrode <b>74</b>, and electrically connected to transparent electrode film <b>65</b>. The upper edge of transparent glass substrate <b>56</b> is equipped with clip electrode <b>76</b>, and electrically connected to transparent electrode film <b>62</b>. Mirror main part <b>78</b> of EC exterior mirror of FIG. 13 replaces arrangement of electrolyte solution <b>68</b> with EC substance film <b>66</b> in FIG. 12. Portions of the same designation as those used in FIG. 1 are designated the same numerals and signs. Mirror main part <b>79</b> of EC exterior mirror of FIG. 14 is composed of EC film <b>80</b> by EC solution. The EC film <b>80</b> is sealed by seal material <b>82</b>. Portions of the same designation as those in FIG. 15 to FIG. 18 are designated the same numerals and signs.

P-0056[0056] Embodiments of EC elements structured transparently in whole part by use of composite material of this invention are shown in FIG. 15 to FIG. 18, respectively. These EC elements can be used as modulated light windows such as a building and vehicles, etc. Portions of the same designation as those used in the respective embodiment are designated the same numerals and signs. In the structure of FIG. 6, transparent electrode film <b>86</b> is arranged replacing electrode-cum-reflective film <b>32</b>, and glass substrate <b>88</b> is structured with a transparent glass substrate. As for EC elements <b>90</b> of FIG. 16, reflective film <b>58</b> and protection coat <b>59</b> are removed in a structure of FIG. 12. As for EC elements <b>92</b> of FIG. 17, the reflective film <b>58</b> and the protection coat <b>59</b> are removed in a structure of FIG. 13. As for EC elements <b>94</b> of FIG. 18, the reflective film <b>58</b> and the protection coat <b>59</b> are removed in a structure of FIG. 14.