JP2972827B2 - UV absorbing transparent body - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a transparent body covered with a coating film having excellent ultraviolet absorption.
These are various window materials as UV-shielding filter-like members,
For example, it is a transparent ultraviolet absorbing material useful for buildings or houses, vehicles, ships, aircraft, and various display devices.

[0002]

2. Description of the Related Art Conventionally, as a processing method for imparting an ultraviolet absorbing property to a transparent body such as a glass substrate, conventionally, there have been known:
It is roughly divided into the following three types.

First, (1) a method in which an ultraviolet absorbing compound is mixed into the transparent body itself. For example, various glass compositions in which a metal compound is melted and added to glass (for example,
No. 47812), or various resin films in which an ultraviolet absorbent is dispersed and added to the resin film (for example, Japanese Utility Model Application Laid-Open No.
No. 17925). Next, (2) a method of bonding an ultraviolet absorbing transparent film to the surface of the transparent body. For example, laminated glass sandwiched via a polyvinyl butyral interlayer containing an ultraviolet absorber (for example, JP-A-56-32352)
Publication). Further, (3) a method of forming an ultraviolet absorbing transparent film on the surface of the transparent body. For example, a vapor phase film forming method such as sputtering on a transparent base material (for example, Japanese Patent Laid-Open No. 4-76083).
Publication) or a liquid phase film forming method such as sol-gel (for example,
Japanese Patent Application Laid-Open No. 4-97103) is known.

On the other hand, recently, a dispersion type fluorescent coating material having a whitening effect, for example, 2.5 bis (5'-tert-butylbenzoxazolyl) thiophene, is used on a resin base material, and a high-temperature high-pressure dyeing method or a normal pressure A method is known in which ultraviolet rays are cut at least 90% or more by a carrier method to obtain a transparent synthetic resin plate having a visible light transmittance of at least 80% or more. (For example, JP-A-61-126503)

[0005]

As described above, for example, Japanese Patent Laid-Open Publication No.
No. 59-17925 are not suitable for small-quantity multi-product production, and those whose absorption wavelength extends to the boundary between the ultraviolet / visible regions (for example, around 400 nm) develop coloring and film clouding. Easy and especially colorless requires some ingenuity, and control is not always easy.

[0006] In addition, the resin described in JP-A-56-32352 has improved chemical resistance, scratch resistance, durability, coloration or cloudiness as compared with the case of using a resin film alone, but it has poor shape compatibility. It's bad, it's quite thick and it's hard to be lightweight.

Further, the compounds described in JP-A-4-76083 or JP-A-4-97103 cannot use a large amount of easily decomposable organic compounds and use an inorganic compound as an absorption base. / The boundary of the visible region may not be sharply cut without coloring, and it may not be applicable to some processed glass such as tempered glass because film formation requires high-temperature firing at about 200 ° C or higher. The conventional method using an organic compound-based coating agent does not require high-temperature sintering, but it is difficult to sharply cut the ultraviolet / visible region without coloring with a thin layer, and a large amount of an ultraviolet absorber is added, so chemical resistance and scratch resistance are required. The properties and durability are considerably inferior.

[0008] Furthermore, the one described in the above-mentioned JP-A-61-126503 absorbs and blocks ultraviolet rays without using an ultraviolet absorber, and has excellent transparency. And the durability is considerably poor in practical use.

[0009]

DISCLOSURE OF THE INVENTION The present invention has been made in view of the above-mentioned conventional problems, and has been made in consideration of the above-mentioned problems. While being applied to the composition, dissolve in a synthetic resin-based primer, especially an acrylic primer coating solution, which has good adhesion to various substrates, especially transparent substrates, and add an ultraviolet absorber Absorbs fluorescence and forms a coating film with inconspicuous fluorescence at a relatively low temperature, and by protecting this with a silicone-based hard coating film, it is non-colored, transparent and sharply blocks ultraviolet rays at around 400 nm. In addition, the present invention provides a useful ultraviolet-absorbing transparent material having excellent chemical resistance, scratch resistance, and durability, which can be used for exteriors.

[0010] That is, the present invention provides a method for producing a transparent base material comprising:
A synthetic resin-based primer coating solution made by dissolving and adding a fluorescent whitening agent and an ultraviolet absorber, heat-curing to form an ultraviolet-absorbing thin film, and a siloxane prepolymer dissolved in an organic solvent. An ultraviolet-absorbing transparent body characterized by being coated successively by applying a coating solution and heat-curing to form a protective thin film.

[0011] The present invention also provides the above-mentioned ultraviolet absorbing transparent material, wherein the synthetic resin-based primer coating solution is an acrylic primer coating solution.

Here, as described above, the fluorescent whitening agent absorbs in the ultraviolet region and emits fluorescence in the visible region,
It can be added to a synthetic resin primer, especially an acrylic primer coating agent, as long as it can be melted and the coating film is not denatured by heat curing at a relatively low temperature. Uvitex-OB (manufactured by Ciba-Geigy Co., Ltd., 2,5bis (5 ′) whose absorption wavelength is on the boundary between the ultraviolet and visible regions (for example, around 400 nm)
-Tert-butylbenzoxazolyl) thiophene) or EB-501 (manufactured by Mitsui Toatsu Dye).

Examples of the ultraviolet absorber to be coexistent include benzophenone, benzotriazole, cyanoacrylate and salicylate.

[0014] The molar ratio of the fluorescent whitening agent to the ultraviolet absorber is about 1: 0.5 to 1: 3.0, preferably about 1: 1. If the amount is too small, the desired ultraviolet absorbing power cannot be obtained.

Further, in the case of a synthetic resin primer, in particular, an acrylic primer, it is necessary to sufficiently dissolve the above-mentioned fluorescent whitening agent and the ultraviolet absorber, so that diacetone alcohol is added to an ether alcohol-based solvent such as ethyl cellosolve. It is preferable to use a mixed solvent in which a transparent base material is not affected by combining a ketone alcohol solvent such as ketone, ether, or an aromatic solvent. In particular, when the transparent substrate is a glass plate or the like, a ketone-based solvent such as cyclohexanone having solubility is preferable.

Further, the synthetic resin is, for example, an acrylic resin, a urethane-based resin, a fluorine-based resin or a polyester-based resin. Among the acrylic resins, a commercially available acrylic BR resin (Mitsubishi Rayon, for example) is used. The concentration may be adjusted according to the relationship of concentration, viscosity or film thickness by using a method such as that described above. The resin component concentration is about 1 to 15 wt%, and the total concentration of the fluorescent brightener and the ultraviolet absorber is about 0.5 to 2 wt%. , Viscosity is 10 ~ 500cP
Preferably, the film thickness is preferably about 1 to 10 μm.

When the transparent substrate is made of glass, a silane coupling agent is preferably used to further improve the adhesiveness. For example, OS808A (acryl-modified silicone manufactured by Daihachi Chemical Co., Ltd.) or the like may be used to increase the resin concentration. It is preferable to add about 1/4 to 1/2 of the above. Too little is ineffective and too much is uneconomical.

Further, the UV-absorbing synthetic resin primer prepared as described above, particularly the UV-absorbing acrylic primer, has a uniform thickness.
For example, it is applied by dipping, spraying, flow coating, printing, or the like to form a film, and is dried by heating at about 80 ° C. or more for about 1 hour, for example, and if it is insufficiently heated, it is a silicone hard coat. The primer component is easily eluted into the protective film, for example, clouding or cracks are easily developed, and if the heating is excessive, the adhesion of the protective film, which is a silicone-based hard coat, deteriorates.

The silicone-based hard coating solution is preferably a solution based on an alcohol solution of a siloxane prepolymer obtained by hydrolyzing an organoalkoxysilane, for example, as proposed by the present applicant. Those containing colloidal silica, such as the coating composition described in JP-A-62-220531, are also excellent in abrasion resistance and are more preferable. For commercial products, for example, Tosgard 510 (made by Toshiba Silicone) or Si coat 2
(Made by Daihachi Chemical) can be used.

Further, as an application environment, for example, a temperature of about
A temperature of about 15 to 25 ° C., a humidity of about 40 to 50 RH%, and a cleanness of about 10,000 or less are preferred from the viewpoint of preventing coating film defects. In addition, as the coating method, like the ultraviolet absorbing synthetic resin primer, particularly the ultraviolet absorbing acrylic primer,
For example, a dipping method, a spray method, a flow coating method, a printing method, or the like can be used so as to obtain a uniform film thickness. The thickness is preferably about 2 to 5 μm. If the thickness is small, the effect of the surface protective film is lost. Further, a temperature of about 80 ° C. or more is preferable for the heat drying and curing. In particular, when the transparent substrate is a glass plate or the like, a treatment at about 150 ° C. for about 2 hours is preferable for increasing the surface hardness.

It is needless to say that a flow improver or a rheology control agent may be appropriately added in order to improve the coating performance of the above-mentioned ultraviolet absorbing acrylic primer or silicone hard coating solution.

Further, the transparent substrate is not particularly limited as long as it has a heat resistance of, for example, about 80 ° C. or higher, and is preferably inorganic glass, PC, PMMA, or the like.
Resin glass such as PET, whether inorganic or organic, not particularly limited in shape, etc., in various shapes, in sizes or configurations, such as bent sheet glass, as well as various tempered glasses Needless to say, it can be used as a high-strength glass, a flat glass or a single plate, and can also be applied as a double glazing or a laminated glass.

[0023]

As described above, according to the present invention, a primer solution in which a fluorescent whitening agent and an ultraviolet absorber coexist is coated with a coating film having a unique structure and excellent in ultraviolet shielding properties and a sufficient protective film. Because it is a transparent material, it absorbs the fluorescence of the fluorescent whitening agent with an ultraviolet absorber and can be formed as an inconspicuous film at a relatively low temperature, and its surface becomes a hard coat, especially in the ultraviolet / visible region around 400 nm. Can be cut very sharply without being transparent and colored, and can be a useful ultraviolet shielding window, etc., which can be used as an exterior, excellent in adhesion, chemical resistance, scratch resistance or durability. A transparent ultraviolet absorbing transparent body can be easily and inexpensively obtained by a simple coating process.

[0024]

The present invention will be described below in detail with reference to examples. However, the present invention is not limited to such an embodiment.

(Preparation of UV-absorbing acrylic primer) [For glass application] 305 g of cyclohexanone and 221 g of propylene glycol monomethyl ether as a solvent are put into a 1000 ml round bottom flask equipped with a stirrer and a circulator, and the acrylic BR is stirred at room temperature. Add 32.5 g of 88 resin (Mitsubishi Rayon). While continuing stirring, 3.25 g of fluorescent brightener UVITEX-OB (Ciba-Geigy) and 3.25 g of UV absorber TINUVIN327 (Ciba-Geigy) are added, and the temperature is raised to about 95 ° C. in about 30 minutes in an oil bath. Hold for about 30 minutes to completely dissolve. Next, the heating was stopped, and the temperature was lowered to room temperature. Then, 65 g of an acrylic modified silicone resin OS-808A was added and dissolved by stirring to obtain an ultraviolet absorbing acrylic primer for glass application.

The UV-absorbing acrylic primer solution was transparent, had a solid content of about 9%, and had a viscosity of about 250 cP (25 ° C.). (Preparation of UV-absorbing acrylic primer) [For resin coating] In a 1000 ml round bottom flask equipped with a stirrer and a circulator, 58.5 g of cyclohexanone and diacetone alcohol 15 were used as solvents.
0 g and 390 g of propylene glycol monomethyl ether are put in, and 45.5 g of acrylic BR-85 resin (manufactured by Mitsubishi Rayon) is charged with stirring at room temperature. While continuing stirring, 3.25 g of fluorescent brightener UVITEX-OB (Ciba-Geigy) and 3.25 g of UV absorber TINUVIN327 (Ciba-Geigy) are added, and the temperature is raised to about 95 ° C. in about 30 minutes in an oil bath. The solution was held for about 30 minutes and completely dissolved to obtain an ultraviolet absorbing acrylic primer for resin application.

The ultraviolet absorbing acrylic primer solution was transparent, had a solid content of about 8%, and had a viscosity of about 35 cP (at 25 ° C.). (Preparation of Silicone Hard Coating Solution) 100 g of methyltriethoxysilane and 10 g of 3-glycidoxypropyltrimethoxysilane are put into a 500 ml round bottom flask equipped with a stirrer and a circulator, and 0.04 g of phthalic anhydride is added. Heat to about 40 ° C to dissolve, then weakly basic colloidal silica aqueous solution Snowtex C (manufactured by Nissan Chemical Industries, average particle size about 15 μm, SiO ₂ content about 20%)
Add 100g and react at about 40 ℃ for about 5 days.
Number average molecular weight about 1100 by C (Tosoh, ULC802A)
A composition having a solid content of about 29% was obtained. To this, 145 g of isopropyl alcohol was added, and the mixture was concentrated with an ultrafilter having a cut-off molecular weight of 1000 (manufactured by Nippon Millipore) to obtain a composition having a number average molecular weight of about 1200 by GPC and a solid content of about 20%. About 0.1 part of dicyandiamide as a curing catalyst was added to the composition to obtain a silicone-based hard coating solution.

(Performance evaluation method) Ultraviolet absorption: An absorption spectrum pattern was measured with an ultraviolet / visible spectrophotometer. Fluorescence: Visual observation under outdoor natural sunlight. (No worries about light emission and clouding.) Surface hardness: Conforms to ASTM D1044, wear wheels CS-10F, 50
0 ΔH (haze) value after rotation (%).

Adhesion: Based on JIS K5400, the number of remaining tapes (1 mm square) tape peeling is indicated by / 100. Chemical resistance: acid ---- 24hr at 25wt% H ₂ SO ₄ infusion test.

Base: 4 hours in a 5 wt% NaOH infusion test. Solvent --- 100% ethanol 4 hours in a drip test. Weather resistance: The time until visual abnormality (film cracking, peeling, noticeable yellowing) is observed with a sunshine carbon weather meter in accordance with JIS D0205.

Example 1 A clear float glass substrate having a size of about 300 mm × 300 mm and a thickness of about 3 mm was washed with a neutral detergent, water rinse, and alcohol sequentially, dried, and then wiped with acetone to form a glass substrate for coating. .

One surface of the glass substrate for coating is film-masked, immersed in the above prepared UV-absorbing acrylic primer solution for glass application, pulled up at a speed of about 0.1 cm / sec, and heated at about 120 ° C. After drying for about 0.5 hour, an ultraviolet absorbing film having a thickness of about 5 μm was formed.

Then, the glass substrate with the ultraviolet absorbing film is immersed in the prepared silicone-based hard coating solution and pulled up at a speed of about 1 cm / sec.
It was dried and cured at about 0 ° C. for about 0.5 hours and at about 150 ° C. for about 0.5 hours to form a protective film having a thickness of about 3 μm.

The obtained ultraviolet shielding glass substrate as an ultraviolet absorbing transparent body was evaluated according to the above-described performance evaluation method.
As a result, as shown in FIG. 1, ultraviolet rays are shielded at a wavelength of 400 nm or less with a transmittance of 5% or less.
In the vicinity of 0 nm, the boundary between the ultraviolet and visible regions can be cut very sharply with sufficient transparency without coloring, preventing the occurrence of worrisome light emission and clouding, and the surface hardness is as high as 5 after the Taber test. It was an abrasion-resistant transparent body having excellent durability, excellent weather resistance for 1000 hours or more, no visual abnormality, no abnormal chemical resistance, and excellent durability.

Example 2 On the same glass substrate as in Example 1, the same primer solution as in Example 1 was used, and a similar film was formed to form a similar ultraviolet absorbing film of about 5 μm.

Next, the glass substrate provided with an ultraviolet absorbing film was immersed in Tosgart 510 (manufactured by Toshiba Silicone Co., Ltd.), which is a commercially available silicone-based hard coating solution, and about 1 cm / sec.
Then, the film was dried and cured at about 120 ° C. for about 3 hours to form a protective film having a thickness of about 3 μm.

The obtained ultraviolet-shielding glass substrate as an ultraviolet-absorbing transparent body was evaluated in the same manner as in Example 1. As in the case of Example 1, the expected excellent ultraviolet absorbing transparent body was obtained. Example 3 A PET film having a thickness of about 50 μ was immersed in the above-mentioned UV-absorbing acrylic primer solution for resin application, and was immersed in about 0.1 cm.
/ Sec at a speed of about 120 ° C,
After drying for about 5 hours, an ultraviolet absorbing film having a thickness of about 5 μ was formed.

Next, the film with an ultraviolet absorbing film is immersed in the prepared silicone-based hard coating solution and pulled up at a speed of about 1 cm / sec.
The film was dried and cured at about 150 ° C. for about 0.5 hours and at about 150 ° C. for about 0.5 hours to form a protective film having a thickness of about 3 μm.

The obtained ultraviolet shielding film as an ultraviolet absorbing transparent material was evaluated in the same manner as in Example 1. As in the case of Example 1, the expected excellent ultraviolet absorbing transparent body was obtained. Comparative Example 1 An ultraviolet-absorbing glass substrate was obtained in the same manner as in Example 1, except that an ultraviolet-absorbing acrylic primer prepared without adding a fluorescent whitening agent UVITEX-OB (manufactured by Ciba-Geigy) was used.

The obtained ultraviolet absorbing glass substrate is almost colorless and transparent on both the indoor side and the outdoor side in appearance, but as shown in FIG. 1, almost no ultraviolet rays can be cut off at a wavelength of about 400 nm. In addition, the boundary between the ultraviolet / visible regions was not always sufficiently sharp, and it was hard to say that the intended ultraviolet-absorbing transparent material was obtained at all.

Comparative Example 2 An ultraviolet absorbing glass substrate was obtained in the same manner as in Example 1 except that an ultraviolet absorbing acrylic primer prepared without adding an ultraviolet absorber TINUVIN327 (manufactured by Ciba Geigy) was used.

The obtained ultraviolet-absorbing glass substrate is uncolored and slightly blue fluorescent in the room in appearance, and exhibits a bluish white cloud under outdoor sunlight. Conspicuous and wavelength 40
The cut near 0 nm was incomplete, and it could not be said to be the expected ultraviolet absorbing transparent body.

Comparative Example 3 An ultraviolet-absorbing glass substrate was obtained in the same manner as in Example 1, except that an ultraviolet-absorbing primer prepared without adding acrylic-modified silicone OS-808A was used.

The obtained ultraviolet-absorbing glass substrate was almost colorless and transparent on both the indoor side and the outdoor side in appearance, but the adhesion of the coating film after the hot water test was poor. It was hard to say that it was an ultraviolet-absorbing transparent body.

[0045]

As described above, according to the present invention,
Without impairing optical properties, it is non-colored and transparent and shields ultraviolet rays. In particular, it can block ultraviolet rays very sharply at around 400 nm in the ultraviolet / visible region, and has good adhesion, chemical resistance, and scratch resistance. The present invention can easily and inexpensively provide a useful ultraviolet-absorbing transparent body which has excellent properties or durability and can be used as an exterior, and can be widely used in various fields such as buildings, houses, and vehicles.

[Brief description of the drawings]

FIG. 1 shows the transmittance of the ultraviolet absorbing transparent body of Example 1 of the present invention, an ordinary glass substrate, and the ultraviolet absorbing glass substrate of Comparative Example 1 in an ultraviolet / visible spectral curve.

Claims (2)

(57) [Claims] 1. A synthetic resin-based primer coating solution obtained by dissolving and adding a fluorescent whitening agent and an ultraviolet absorber on the surface of a transparent base material, followed by heat curing to form an ultraviolet absorbing thin film. An ultraviolet-absorbing transparent body, wherein a protective thin film is formed by applying a silicone-based hard coating solution obtained by dissolving a polymer in an organic solvent and curing by heating. 2. The ultraviolet absorbing transparent body according to claim 1, wherein the synthetic resin primer coating solution is an acrylic primer coating solution.