JP3486202B2 - Translucent surface protective laminated film and method for producing the same - Google Patents

Description

Detailed Description of the Invention

[0001]

FIELD OF THE INVENTION The present invention relates to a translucent surface protective laminated film having a high light transmittance, a low reflectance, a high surface hardness and mechanical strength, and excellent water resistance and ultraviolet resistance. ,
In particular, the present invention relates to a translucent surface protective laminated film suitable for surface protection of solar cells or electrophotographic photoreceptors, and a method for producing the same.

[0002]

2. Description of the Related Art Light-transmitting surface protective films are widely used in the fields of utilizing light, such as solar cells and electrophotography.
Transparent resin or transparent glass is used.

Solar cells are currently used in a wide range. The structure of the module (a unit in which a number of solar cells are wired in series and in parallel according to the purpose and enclosed) is a substrate method (modules are arranged on the lower substrate and the solar cells are enclosed with transparent resin). ),
The super straight method (a method in which a transparent substrate such as glass is placed on the light receiving surface side of the solar cell to serve as a module support plate, the periphery of which is filled with transparent resin, and the solar cell is encapsulated using a backside coat) is used. ing. Since the solar cell uses electromotive force generated by receiving sunlight, high light receiving efficiency, that is, high light transmittance and low reflectance are required. However, the transparent resin and transparent glass used here have high light reflectance and insufficient light transmittance of sunlight, and this light transmittance is low as the exposure time is prolonged, resulting in low effective transmittance. Only electricity can be obtained. Further, oxidation due to ultraviolet rays causes a decrease in water resistance and insulation failure, resulting in insufficient mechanical strength and hardness, which causes many practical problems. For example, in a solar cell, as a transparent resin, polyvinyl butyral, which has a small decrease in light transmittance due to ultraviolet rays, or ethylene vinyl acetate, which has excellent moisture resistance, is used, and as transparent glass, it has excellent light transmittance and impact resistance. A tempered glass obtained by thermally strengthening white plate glass is used. However, since the solar cell is constantly exposed to sunlight, all of these materials rapidly deteriorate in ultraviolet resistance, water resistance, and weather resistance, and as a result, the solar cell element becomes difficult to operate. Further, for use in a solar cell, ideally, a light transmittance of 100% and a reflectance of 5% or less are required, but the above materials are far from these requirements.

With respect to the surface protection of electrophotographic photoconductors, there are demands for improvement in light transmittance, reflectance, surface hardness, etc., which are common to those in the case of solar cells. However, the protective film made of resin as described above has a poor light receiving efficiency. Further, in the case of an electrophotographic photoreceptor, the degree of which mechanical strength is particularly required is high. Therefore, in the case of a resin or the like, there is a problem that the surface is easily scratched.

Therefore, in order to protect solar cells, electrophotographic photoreceptors and the like, development of a protective film having excellent translucency which overcomes the above-mentioned drawbacks is under way.

It is theoretically considered that the light transmittance and hardness of the protective film depend on the composition of the film (for example, when the protective film is made of a metal oxide, its composition and oxidation state) and the porosity. That is, if the composition is constant, the porosity of the film decreases as the film density increases, and the light transmittance and the film hardness increase. However, when forming the protective film, it is necessary to consider various factors such as the thermal deformation point of the base material, the thickness of the protective film, and the drying temperature when forming the protective film. In particular, when forming a film by vapor deposition, it is necessary to consider the vapor deposition temperature and the degree of vacuum. Therefore, it is not easy to produce a protective film that is satisfactory in terms of hardness, durability (especially UV resistance and water resistance) and adhesion between the protective film and the substrate.

When a substance is exposed to light, reflection, absorption, refraction,
Phenomena such as scattering and dispersion occur. The behavior of this light is theoretically governed by the optical constants of the substance such as the refractive index and the extinction coefficient. Particularly in the case of a material optically applied to a solar cell, it is necessary to transmit the visible light portion of sunlight, and the light interference effect is used to minimize reflected light.

Generally, glass has a total reflectance of about 8% on both front and back sides with respect to visible light. It is theoretically known that this reflectance can be reduced by coating the glass with either a low refractive index film, a multilayer interference film, or a porous layer film.

The low refractive index film utilizes the light interference effect. The reflectance can be reduced by using a thin film having a lower refractive index than glass. The low refractive index material various fluorides (e.g., MgF ₂ and AlF ₃ · 3NaF i.e. cryolite) can be mentioned are, but practically problematic like. If the composition is constant, the larger the porosity, the lower the refractive index of the film. However, as described above, the light transmittance is improved as the porosity is smaller. Have difficulty.

The multilayer interference film is formed by alternately laminating high refractive index films and low refractive index films based on the theory of light interference.
It has a lower reflectance than a single-layer film and has a wide low reflection region according to the number of layers. For example, the spectral characteristics of the alternating multilayer film of TiO ₂ and SiO ₂ greatly differ depending on the number of layers.

The porous layer film includes a skeleton layer and the like. This is a sponge-like porous layer obtained by acid-treating the surface of glass. In this case, the antireflection effect is considered to be due to the difference in the refractive index between the porous layer having a pore size smaller than the wavelength of light (300 angstroms or less) and the base glass, and the porosity of the porous layer.

Although there are various methods for reducing the reflectance as described above, there are problems such as film thickness and cracks, and it is difficult to put them into practical use.

[0013]

SUMMARY OF THE INVENTION The present invention solves the above-mentioned conventional drawbacks, and its object is to have a high light transmittance and a low reflectance, a high surface hardness and a high mechanical strength. However, it is to provide a translucent surface protective laminated film having excellent water resistance and ultraviolet resistance. Another object of the present invention is to provide a method for producing the translucent surface protective laminated film.

[0014]

The translucent surface protective laminated film of the present invention is a translucent surface protective laminated film composed of at least two layers laminated on at least one surface of a substrate. The first layer formed above is obtained by hydrolyzing and polycondensing a composition containing at least two metal alkoxides containing magnesium alkoxide, an alkoxysilane, and a silane coupling agent by a sol-gel method. The second layer formed on the surface of the first layer is composed of a composite polymer whose main component is inorganic, and the second layer is hydrolyzed by a sol-gel method to a composition containing a metal alkoxide and a silane coupling agent. And a complex polymer obtained by polycondensation, the main component of which is organic, whereby the above object is achieved.

The method for producing a translucent surface protective laminated film of the present invention contains at least two metal alkoxides containing magnesium alkoxide, an alkoxysilane, a silane coupling agent, a mineral acid, a base catalyst, water and an organic solvent. A step of applying and drying the first coating liquid on at least one surface of the substrate; a second coating liquid containing a metal alkoxide, a silane coupling agent, water and an organic solvent on the surface of the first coating layer. Applying step; and the first coating layer and the second coating layer
The step of heat-treating the laminated film composed of the coating layer at 120 ° C. or higher; thereby achieving the above object.
In order to reduce the light reflectance, it is possible to further repeat the above-mentioned lamination process to form a surface protective laminated film having a desired translucency and reflectance.

The material of the base material capable of forming the translucent surface protective laminated film of the present invention is not particularly limited, but various resins, particularly base materials made of a thermoplastic resin or having a main component thereof, a glass plate, Alternatively, a metal plate is preferably used. The form of the substrate may be a film, a sheet, a plate, or any other type of molded article. As the thermoplastic resin, a polycarbonate resin, a polyolefin resin, a polyester resin, a polyether resin, a polyamide resin, a vinyl resin,
There are cellulosic resins and the like. These resins may be homopolymers or copolymers. Examples of the glass plate include silica glass and borosilicate glass, which have high transparency and strength suitable for the substrate. Examples of metal plates include aluminum plates, duralumin plates, and SUS plates.

The alkoxysilane used in the present invention is
It is represented by Si (OR ¹ ) ₄ and R ¹ is a lower alkyl group (having 1 to 4 carbon atoms). For example _{Si (O-CH 3) 4} , Si
_{(O-C 2 H 5)} 4 is used. These alkoxysilanes may be used as a mixture.

The metal alkoxide used in the present invention includes magnesium alkoxide, aluminum alkoxide, titanium alkoxide, zirconium alkoxide and the like. You may mix and use 2 or more types of these metal alkoxides. These metal alkoxides have a lower alkoxy group. For example, magnesium alkoxide is represented by Mg (OR ² ) ₂ and R ² is a lower alkyl group. Specifically, Mg (OCH ₃ ) ₂ , Mg
(OC ₂ H ₅ ) ₂ , Mg (OC ₃ H ₇ ) ₂ , Mg (OC ₄ H ₉ )
_2, etc. may be used: aluminum alkoxide
It is represented by Al (OR ³ ) ₃ and R ³ is a lower alkyl group.
For example, Al (OCH ₃ ) ₃ , Al (OC ₂ H ₅ ) ₃ , Al
(OC ₃ H ₇ ) ₃ and Al (OC ₄ H ₉ ) ₃ are used: The titanium alkoxide is represented by Ti (OR ⁴ ) ₄ and R
⁴ is a lower alkyl group. For example, Ti (O-CH _{3)
4, Ti (O-C 2} H 5) 4, Ti (O- C 3 H 7) 4, Ti
_{(O-C 4 H 9)} 4 is used: zirconium alkoxide is represented by _{^{Zr (OR 5) 4, R}} 5 is a lower alkyl group. _{Specifically, Zr (O-CH 3)} 4, Zr (O
_{-C 2 H 5) 4, Zr} (O-C 3 H 7) 4, Zr (O-C
₄ H ₉ ) ₄ etc. can be used: each metal alkoxide is 2
You may mix and use 1 or more types.

The metal alkoxide for forming the first layer formed on the substrate contains magnesium alkoxide. The amount used is 0.01 to 3% by weight, preferably 0.01 to 0.03% by weight, based on the total weight of the coating liquid for forming the first layer. The addition of magnesium alkoxide produces a trace amount of MgO, preventing the growth of alumina particles during sol-gel hydrolysis,
The size of the alumina particles inside the coating is kept below the wavelength of visible light. This can improve the transparency of visible light.

The metal alkoxide for forming the first layer preferably further contains an aluminum alkoxide and / or a titanium alkoxide.

By using the aluminum alkoxide, the hardness of the resulting protective film is increased and the surface hardness of the base material is improved. The amount used is 50 parts by weight or less, preferably about 30 parts by weight, based on 100 parts by weight of the alkoxysilane in the coating liquid for forming the first layer. When it exceeds 50 parts by weight, rigidity and brittleness of the formed composite polymer are increased, and as a result, the coating film is easily cracked or peeled off.

By using the titanium alkoxide, the hardness of the resulting protective film is increased and the surface hardness of the base material is remarkably improved. The amount used is 30 parts by weight or less with respect to 100 parts by weight of the alkoxysilane,
It is preferably about 20 parts by weight. When it exceeds 30 parts by weight, rigidity and brittleness of the formed composite polymer are increased, and as a result, the coating film is easily peeled off.

The metal alkoxide for forming the first layer may further contain zirconium alkoxide. The zirconium alkoxide improves the toughness and heat resistance of the resulting protective film by using the zirconium alkoxide. The amount used is in the range of not more than 10 parts by weight, preferably about 5 parts by weight, based on 100 parts by weight of the alkoxysilane. If it exceeds 10 parts by weight, the formed composite polymer tends to gel,
The brittleness is increased, and as a result, the protective film is easily peeled off.

The metal alkoxide for forming the second layer formed on the first layer preferably contains magnesium alkoxide. The amount of magnesium alkoxide used for forming the second layer is the same as in the case of the above-mentioned first layer, and is 0.01 to 3 of the total weight of the coating liquid for forming the second layer. % By weight, preferably 0.01 to 0.03% by weight.

The metal alkoxide for forming the second layer preferably further contains an aluminum alkoxide. The amount of its use in the coating solution for forming the second layer is 3 to 20% by weight, preferably about 8.5% by weight, based on the total weight of the coating solution.

The silane coupling agents used with the above alkoxides include organoalkoxysilanes containing known reactive organic substituents. In particular, an organoalkoxysilane containing an epoxy group is suitable.
Examples thereof include γ-glycidoxypropyltrimethoxysilane, γ-glycidoxypropylmethyldiethoxysilane, β- (3,4-epoxycyclohexyl) ethyltrimethoxysilane, and the like. You may mix and use 2 or more types of such a silane coupling agent. The amount used is 10 to 5 with respect to 100 parts by weight of alkoxysilane in the coating liquid for forming the first layer.
Within the range of 0 parts by weight. When 50 parts by weight or more is used, the hardness of the formed composite polymer is lowered. In the coating liquid for forming the second layer, it is used in a proportion of 400 to 700 parts by weight relative to 100 parts by weight of the aluminum alkoxide, and the entire coating liquid for forming the second layer. Used in an amount of 30 to 60% by weight.

Base catalysts used primarily in the polycondensation catalyst used in the process of the present invention include tertiary amines which are substantially insoluble in water and soluble in organic solvents.
Examples thereof include N, N-dimethylbenzylamine, tripropylamine, tributylamine and tripentylamine, with N, N-dimethylbenzylamine being particularly preferred. The amount used is 0.1 to 1 part by weight, preferably about 0.3 part by weight, per 100 parts by weight of the total amount of the alkoxysilane, the metal alkoxide, and the silane coupling agent.

The mineral acid used in the method of the present invention is sol-
It acts as an acid catalyst in the gel method and also has a function of dissolving aluminum alkoxide. Examples thereof include sulfuric acid, hydrochloric acid and nitric acid. The amount of the mineral acid used is alkoxysilane, metal alkoxide, and the alkoxide portion of the silane coupling agent (OR ¹ , OR ² , O in the case of alkoxysilane and metal alkoxide).
1 to 10 parts by weight, preferably about 5.0 parts by weight, relative to 100 parts by weight of R ³ , OR ⁴ or OR ⁵ ).

First and Second Used in the Method of the Invention
In the coating liquid of 1 to 1 part by weight with respect to the total of 100 parts by weight of alkoxysilane and metal alkoxide,
30 parts by weight of water are used. When the amount of water exceeds 30 parts by weight, the hydrolysis of the alkoxysilane and the metal alkoxide proceeds excessively, so the composite polymer obtained by polycondensation of the hydrolyzate is highly crosslinked, and is porous and has a high density. It is a low polymer. As a result, the surface hardness of the base material cannot be improved. When the amount of water is less than 1 part by weight, the hydrolysis reaction is difficult to proceed.

As the organic solvent used in the method of the present invention, a solvent compatible with water such as ethyl alcohol, isopropyl alcohol and butyl alcohol is used. The amount used is usually 50 to 150 parts by weight per 100 parts by weight of the total of the above alkoxysilane, metal alkoxide, silane coupling agent, water, mineral acid and base catalyst.

According to the method of the present invention, the translucent laminated surface protective film of the present invention is formed, for example, as follows.
First, the above-mentioned alkoxysilane, metal alkoxide (including magnesium alkoxide and optionally other metal alkoxide), silane coupling agent, mineral acid, sol-gel method (base) catalyst and organic solvent are mixed to obtain a coating liquid. Is prepared (this is referred to as coating liquid A). Similarly, a metal alkoxide, a silane coupling agent, water, an organic solvent, and, if necessary, an acid catalyst and / or a base catalyst are mixed to prepare a second coating liquid (this is referred to as coating liquid B). ). The coating liquid A has a higher content of inorganic components than the coating liquid B. When a translucent surface protective laminated film is prepared using the coating liquids A and B as described below, in the first layer prepared from the coating liquid A, the component ratio of the inorganic substance and the organic substance ( The weight ratio is in the range of 95: 5 to 60:40, preferably 80:20. Second prepared from coating liquid B
In the layer (1), the ratio of the constituents (weight ratio) of the inorganic substance and the organic substance is in the range of 30:70 to 50:50, preferably 40:60. Here, the term “inorganic” means SiO ₂ and Al ₂ O ₃ when it is considered that the alkoxysilane, the metal alkoxide and the silane coupling agent contained in the coating liquid are all condensed to remove the produced alcohol and the like from the system. Refers to the portion converted to the form of metal oxide such as. Here, the term "organic substance" means a portion of the substituent other than the alkoxy group of the silane coupling agent. When the coating liquid A is applied to the surface of the base material and air-dried at room temperature to bring it into a touch-free state, the coating liquid B is applied to the surface. After being dried, it is heated at a temperature in the range of 120 ° C. to 150 ° C. for 1 minute to 10 minutes to obtain the laminated protective film of the present invention. If necessary, the coating liquids A and B are sequentially applied in this order, lamination is repeated, and the above heat treatment is performed to obtain a laminated protective film having a desired surface hardness.

The translucent surface protective laminated film of the present invention obtained as described above imparts a desired hardness to the surface of the substrate,
Moreover, the protective film has excellent adhesion to the substrate. The water resistance of the surface of the base material, especially the hot water resistance, also increases dramatically.

[0033]

In the method of the present invention, the alkoxysilane and the metal alkoxide in the coating liquid A are hydrolyzed (mainly acting as an acid catalyst) to form a hydroxyl group. Next, the sol-gel method catalyst (base catalyst) acts to deprotonate the hydroxyl groups, resulting in dehydration polycondensation of the hydrolysis products. At this time, at the same time, the alkoxy group of the silane coupling agent is also hydrolyzed to generate a hydroxyl group, and the epoxy group is also opened by the action of a base catalyst to generate a hydroxyl group. The polycondensation reaction of the hydrolyzed silane coupling agent with the hydrolyzed alkoxysilane and the metal alkoxide also proceeds. The polycondensate produced is
Inorganic moieties consisting of bonds such as Si-O-Si, Si-O-Al, Si-O-Ti, and organic moieties resulting from moieties other than alkoxy groups of silane coupling agents, such as moieties containing epoxy groups. Is a composite polymer containing

In the above reaction, for example, in addition to the partial structural formula represented by the formula (I), a three-dimensional network polymer having a part derived from the silane coupling agent is first produced. The polymer has an alkoxy group in a network structure. It is considered that the alkoxy group is hydrolyzed by the catalytic action of the existing mineral acid to form a hydroxyl group, and the hydroxyl group further forms a bond to form the composite polymer represented by the formula (II). In the polycondensation reaction, the hydroxyl group is first deprotonated by the action of the sol-gel method catalyst (base catalyst), and then the polycondensation proceeds. Here, the following formulas (I) and (II) exemplify a part of a continuous three-dimensional crosslinked structure and are not limited to this structure. The wavy line (-) in the formula (II) represents an organic chain between a reactive organic substituent in the molecule of the silane coupling agent used, for example, an epoxy group and silicon in the molecule of the silane coupling agent. It is a part derived from. For example, when γ-glycidoxypropyltrimethoxysilane is used as the silane coupling agent, this wavy line portion is -C.
_{H 2 OCH 2 CH 2 CH 2} - corresponding to.

[0035]

[Chemical 1]

In the method of the present invention, hydrolysis and polycondensation reactions proceed in the process of preparing the coating solution. For example, the coating liquid A contains SiO ₂ , Mg ₂ O,
A composite polymer composed of an inorganic component capable of containing Al ₂ O ₃ and TiO ₂ and an organic component derived from a substituent other than the alkoxy group of the silane coupling agent is produced, and the composite polymer is easily dried at room temperature in air. It becomes dry to the touch and forms a soft film. The above coating liquid B applied to the upper layer also produces a composite polymer by hydrolysis and polycondensation reaction between the silane coupling agent and the metal alkoxide. In the film formed of the coating liquids A and B, polycondensation completely proceeds and is cured by heating and drying at a temperature of 120 ° C to 150 ° C.

At this time, the composite polymer of the second layer (upper layer) formed from the coating liquid B contains a large amount of reactive organic substituents derived from the silane coupling agent, for example, epoxy groups. As described above, the epoxy group of the silane coupling agent is ring-opened by the base catalyst, polymerized by heating, and cured to become a high density polymer. As a result, the coating film undergoes heat shrinkage, resulting in a unique compressive stress when the epoxy group is cured. On the other hand, the composite polymer of the first layer (lower layer) formed by the coating liquid A undergoes a relatively slow drying shrinkage inside, so that a compressive stress from the second layer is easily applied, whereby the first layer (lower layer) is formed. The density of the inorganic portion of the layer increases. In the process of cooling and solidification, the compressive stress due to the increase in the internal density of the first layer acts on the hardened second layer, and the hardness thereof is further improved. In this way, by forming a strong compressive stress layer (second layer), the density is increased by the amount of compressive stress against tension fracture, the molecular arrangement and hardness are strengthened, and the porosity of the first layer is increased. Is reduced, and a dense light-transmitting layer is formed as the density increases. Furthermore, due to the difference in refractive index between the first layer and the second layer, a high-refractive index film and a low-refractive index film are alternately laminated to form a multilayer interference film, the surface of which is like a skeleton layer. It becomes a porous layer having a pore size smaller than the wavelength of light to reduce the reflectance.

The mechanism for improving the surface strength is similar to the principle of the physical strengthening method and the chemical strengthening method for increasing the surface height of glass. The physical strengthening method (wind cooling strengthening method) is a method in which glass is heated to near its softening temperature and then rapidly cooled. Upon rapid cooling, the glass surface immediately solidifies to form a strong compressive stress layer, and the interior relatively cools and contracts relatively slowly, so compressive stress is applied to the surface layer. As a result, the tensile stress is strengthened by the compressive stress. The chemical strengthening method (ion strengthening method) is a method in which alkali ions (sodium ions) in glass are replaced with larger monovalent ions and a compressive stress is generated by increasing the volume thereof.

Only the above coating liquid A is applied to the base material to form 120-
When dried and solidified at 150 ° C, especially when the substrate is resin,
The resulting coating has fine cracks on the entire surface and also has poor adhesion to the substrate. This is due to the difference in the coefficient of thermal expansion and the degree of shrinkage between the resin of the base material and the composite polymer produced from the coating liquid A. On the other hand, the coating liquid A is air-dried at room temperature to form a soft first layer, and the first layer is coated with the second layer of the coating liquid B containing more organic substances. hand,
When dried and solidified under the same conditions, the density of the inorganic component of the first layer increases due to the internal stress generated while being protected by the toughness of the organic component of the composite polymer of the second layer that is solidified and heat-shrinked. Therefore, no crack occurs.

When a solar cell element is placed on a glass plate and a SUS plate by the method of the present invention and the laminated protective film is coated, the spectral absorption in the ultraviolet / visible light region, that is, the light transmittance is 100%. The reflectance is 5% or less.
Furthermore, it shows excellent performance in terms of weather resistance, surface hardness, adhesion, impact resistance, fire resistance, etc., and has semi-permanent protective performance as a surface protective film suitable for solar cells and electrophotographic photoreceptors. Came to show.

The purpose of use of the translucent surface protective laminated film of the present invention is not limited to the above-mentioned solar cells and electrophotographic photoreceptors, but it is applicable to a wide range of fields where performances such as high light transmittance and low reflectance are required. It can be applied. For example, it can be suitably used for an optical lens, a cover glass for instruments, a solar heat collecting plate, or an antireflection surface coating agent.

[0042]

EXAMPLES The present invention will be described below based on examples.

The titanium tetraisopropoxide according to the components (each parts by weight) shown in Table 1, magnesium c Muetokishido, aluminum isopropoxide, ethyl silicate, ethanol, hydrochloric acid (Tables 1 and 2 HCl is dry HCl Conversion hydrochloride Amount), and water,
The mixture was stirred at room temperature (about 25 ° C). After stirring for about 30 minutes to 2 hours, the silane coupling agent SH prepared in advance
6040 (manufactured by Toray Dow Corning) and an ethanol solution of N, N-dimethylbenzylamine were added and further stirred to obtain a coating liquid A.

Next, according to the components shown in Table 2 (each part by weight), aluminum isopropoxide, magnesium ethoxide, hydrochloric acid, ethanol and water were mixed and stirred at room temperature (about 25 ° C.). SH6040 (manufactured by Toray Dow Corning) prepared in advance after stirring for about 30 minutes
The ethanol solution of was added and further stirred to obtain a coating liquid B.

A glass plate or a SUS plate was used as the substrate. The coating liquid A was applied to the surface of the base material in a uniform thickness, and dried by air drying for 2 to 3 minutes. At the time when the surface becomes dry to the touch, apply the coating liquid B to the surface in a uniform thickness,
It heat-processed for 3 to 10 minutes in a 150 degreeC drying oven.

The spectral absorption in the ultraviolet / visible region of the obtained laminated film was measured, and as a result, at this stage, the visible light absorption was 100%.
And the reflectance was 5% or less. Furthermore, when a change in appearance was observed using a Xe sunshine weather meter for a weather resistance test, it began to turn yellow after 10,000 hours.
It turned brown at 10,000 hours. This corresponds to a weather resistance of 10 years or more. The pencil hardness is 4H,
The adhesion was 100/100 in the crosshatch test. When 500 g was dropped from a height of 430 mm in order to test the impact resistance, only slight peeling occurred. When a flame was approached to test the fire resistance, there was no ignition.

[0047]

[Table 1]

[0048]

[Table 2]

[0049]

According to the present invention, a first coating liquid containing at least two metal alkoxides containing magnesium alkoxide, an alkoxysilane, and a silane coupling agent, and a metal alkoxide and a silane coupling agent are contained. The light-transmitting surface protective laminated film is formed by sequentially applying the second coating liquid to the base material and curing it. This translucent surface protective laminated film has high light transmittance, low reflectance, high surface hardness and mechanical strength, and excellent water resistance and ultraviolet resistance. It is preferably used for protecting the surface of the body and the like.

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁷ Identification symbol FI C09D 183/00 C09D 183/00 G02B 1/04 G02B 1/04 (72) Inventor Shigeo Yoshida Oshima Shinohara, Yasu-cho, Yasu-gun, Shiga Prefecture No. 6 in Nakato Research Institute Co., Ltd. (56) Reference JP-A-5-179027 (JP, A) JP-A-61-142605 (JP, A) JP-A-55-21251 (JP, A) (58) Survey Areas (Int.Cl. ⁷ , DB name) B32B 1/00-35/00 C08J ⁷ /04-7/06

Claims (8)

(57) [Claims] 1. A translucent laminated film comprising at least two layers laminated on at least one surface of a base material, wherein the first layer formed on the base material is at least two kinds containing magnesium alkoxide. metal alkoxides, alkoxysilanes, and the composition containing the silane coupling agent sol - obtained by combined hydrolysis and polycondensation by the gel method, the weight ratio of the non-machine quality and organic 95: 5-6
A second layer formed of a composite polymer in the range of 0:40 and formed on the surface of the first layer hydrolyzes a composition containing a metal alkoxide and a silane coupling agent by a sol-gel method. And a translucent surface protective laminated film formed from a composite polymer having an organic main component, which is obtained by polycondensation. 2. The translucent surface protective laminated film according to claim 1, wherein the metal alkoxide for forming the second layer is at least two kinds of metal alkoxide containing magnesium alkoxide. 3. A metal alkoxide other than magnesium alkoxide for forming the first layer, which contains at least aluminum alkoxide and titanium alkoxide, and which is used for forming the second layer, other than magnesium alkoxide. The translucent surface protective laminated film according to claim 2, containing at least aluminum alkoxide as the metal alkoxide. 4. A first coating liquid containing at least two metal alkoxides containing magnesium alkoxide, an alkoxysilane, a silane coupling agent, a mineral acid, a base catalyst, water and an organic solvent on at least one side of a substrate. Application /
A step of drying; a step of applying a second coating liquid containing a metal alkoxide, a silane coupling agent, water and an organic solvent to the surface of the first coating layer; and the first coating layer and the second coating layer 1 layered film consisting of coating layers
A step of heat-treating at 20 ° C. to 150 ° C .; 5. The method for producing a translucent surface protective laminated film according to claim 4, wherein the metal alkoxide contained in the second coating liquid is at least two kinds of metal alkoxide containing magnesium alkoxide. 6. The second coating liquid contains the silane coupling agent in an amount of 30% by weight to the total weight of the second coating liquid.
The method for producing a light-transmitting surface protective laminated film according to claim 4, wherein the light-transmitting surface protective laminated film is contained in an amount of 60% by weight. 7. A metal alkoxide other than magnesium alkoxide contained in the first coating liquid, containing at least aluminum alkoxide and titanium alkoxide, and other than magnesium alkoxide contained in the second coating liquid. Contains at least an aluminum alkoxide as the metal alkoxide of
The method for producing the translucent surface protective laminated film according to claim 5. 8. The method for producing a translucent surface protective laminated film according to claim 4, wherein the base catalyst is a tertiary amine which is substantially insoluble in water and soluble in an organic solvent.