JPH1180596A - Masking agent and formation of patterned film - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a masking agent, used when forming a functional thin film and useful for forming a patterned film of a prescribed shape on a substrate by compounding an inorganic fine powder with a cellulosic resin for thickening and an organic solvent in a specific proportion. SOLUTION: This masking agent is used for forming a patterned film of a prescribed shape on a substrate and obtained by compounding (A) an inorganic fine powder which is any one or more of fine powdery silica, barium silicate and cerium oxide with (B) a cellulosic resin composed of a nitrocellulose for thickening or the like and (C) an organic solvent which is any one or more of ethyl carbitol, butyl carbitol and 3-methoxybutyl acetate at 0.15-2.30 weight ratio of the components A/B. The amounts of the compounded components is 5-50 wt.% solute concentration of the total components A and B. The resultant composition is useful for forming a functional thin film such as a wavelength selective film, e.g. an ultraviolet ray shielding film, an infrared ray shielding film or a visible ray reflection film, an electromagnetic wave shielding film, a decorative film or the like on a substrate such as glass or ceramics.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a wavelength selective film such as an ultraviolet shielding film, an infrared shielding film, a visible light reflecting film, a visible light low reflecting film, etc. on a substrate such as glass or ceramics.
The present invention relates to a masking agent used for forming a functional thin film such as an electromagnetic wave shielding film, a decorative film, or a composite film thereof, and a method of forming a pattern film thereof.

[0002]

2. Description of the Related Art Conventionally, a water-soluble masking agent is applied on a substrate in advance to form a masking layer, and then the entire surface of the substrate including the masking layer is coated with a water-insoluble paint, and then washed with water to form a masking layer and a masking layer. A method of forming a pattern film for removing a coating film on a masking layer is disclosed in, for example, JP-A-7-3.
No. 31,180 and JP-A-3-56170. Further, as a water-insoluble material, for example, a solution using an organic solvent solution containing a polyurethane resin as an essential component as a masking agent is known in JP-A-62-213879.

[0003]

The above-mentioned conventional method of applying a water-soluble masking agent can be very suitably used for relatively simple patterning since water is used as a solvent for the masking agent. However, when a precise and complicated pattern is continuously formed while the masking agent is directly exposed to the outside air for a long time, the masking agent is easily dried, the printing workability is impaired, and the screen flow of the masking agent is reduced. There is a drawback that the printability is lacking due to the low printability.

[0004]

SUMMARY OF THE INVENTION The present invention has been made in consideration of the above-mentioned problems, and has been made in consideration of the above circumstances. In order to improve the printability by dispersing an inorganic fine powder, which is a main forming material of the coating, in a high-boiling organic solvent that is incompatible with the inorganic fine powder and further imparting a suitable viscosity to the masking agent during printing, It has been found that the above-mentioned problem can be solved by mixing a cellulose-based resin such as nitrocellulose which does not react with the organic solvent and is easily scattered by burning during firing.

The present invention relates to a masking agent used for forming a pattern film of a predetermined shape on a substrate, comprising a fine inorganic powder, a cellulose resin for thickening, and an organic solvent. A weight ratio of 0.15 to 2.30, and a solute concentration of the inorganic fine powder and the cellulose resin of 5 to 50% by weight. When forming by stencil printing, flexographic printing, stamping method, etc., the masking agent does not dry out even in long-time work and does not hinder printability, and also has fluidity suitable for printability It is.

As the inorganic fine powder, it is preferable to use one or more of fine powder silica, barium sulfate and cerium oxide. Further, the cellulose resin is preferably nitrocellulose having a degree of polymerization of at least one of H7, H20, H60, H80, and H120 specified in JIS K6703.

Further, as the organic solvent, it is preferable to use one or more of ethyl carbitol, butyl carbitol and 3-methoxybutyl acetate. The viscosity of the masking agent for screen printing is
It is preferably from 7 to 300P.

According to the present invention, in a method of forming a pattern film of a predetermined shape on a substrate, a film is formed on a portion other than the pattern of the predetermined shape by using the masking agent according to claim 1 to form a masking layer. After drying at 50 to 250 ° C., a functional film is formed on the entire surface of the substrate using a solution obtained by adding a solvent to a metal organic compound, a metal inorganic compound, or a mixture thereof, and fired at a temperature of 200 ° C. or more. Thereafter, the present invention relates to a method of forming a pattern film for removing a portion of the masking layer together with a functional film thereon.

[0009]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The substrate used in the present invention is glass,
Ceramics, metals, etc., and their composition, shape, size, color tone, etc. are not limited. , Inorganic fine powder,
It is desirable to use fine soft particles that do not dissolve in the organic solvent, and that are decomposed when the masking film is removed so that the functional film does not scratch the functional film. Any material may be used as long as it is fine, but examples thereof include finely divided silica, barium sulfate, and cerium oxide. Preferred average particle size is 0.1 to
1.5 μm.

As the thickener, a cellulosic resin is used,
Particularly, nitrocellulose is preferred. When using nitrocellulose, when forming a functional film using a solution containing a metal organic compound, a metal inorganic compound or a mixture thereof, as a diluting solvent, ethanol, isopropyl alcohol, butanol and other relatively low-grade Alcohol or an alcohol derivative such as methoxypropanol, ethoxyethanol or ethyl cellosolve is generally used, but the masking layer is also immersed in a coating liquid containing these alcoholic organic solvents as a main component. Is not easily melted.

When nitrocellulose is used, the degree of polymerization is preferably H7, H20, H60, H80, H12.
It is preferable to use any one or more of zero. When these types of nitrocellulose are used, the viscosity of the ink decreases in response to the shear stress applied to the masking agent (printing ink) by a squeegee or the like during printing, and the so-called shear thinning viscosity increases. Even if the viscosity of a masking agent prepared by adding cellulose as much as 10 parts by weight or more is 200 P or more, the apparent viscosity decreases to about 1 to 10 P due to shear thinning during printing. This is because up to 300P can be suitably used without impairing printability. In this case, the degree of polymerization of nitrocellulose is H2, H1, H1 / 2, H1 /
When 4, H1 / 8, H1 / 16, etc. are used, the shear thinning viscosity is small, and in order to increase the viscosity, it is necessary to increase the amount of addition, and thereby the printability is greatly impaired. .

Further, the organic solvent for the masking agent is any one of ethyl carbitol, butyl carbitol, and 3-methoxybutyl acetate, which easily dissolves nitrocellulose, has a high boiling point, and is hardly dried at room temperature. The above are preferred.

In the masking agent, (inorganic fine powder)
/ (Cellulose resin) weight ratio of 0.15 to 2.30
It is desirable that When the thickness is less than 0.15, if the masking agent is firmly baked on the substrate after drying at 200 ° C. or higher after forming the functional film, the masking film tends to be hardly peeled off even with wiping and the workability tends to deteriorate. ,
In particular, this tendency becomes remarkable at a high temperature of 300 to 500 ° C. On the other hand, if it is 2.30 or more, it becomes difficult to uniformly mix the cellulosic resin and the inorganic fine powder, and even if a masking film can be formed, it tends to separate into a powder form when immersed in the coating liquid. is there.

Further, the solute concentration of the inorganic fine powder and the cellulosic resin in the masking agent is preferably 5 to 50 parts by weight. If the amount is less than 5 parts by weight, the viscosity of the prepared masking agent becomes too low, resulting in poor film formability and printability, and the thickness of the masking agent becomes too thin, resulting in a reduced masking function. On the other hand, when the amount is more than 50 parts by weight, the viscosity is conversely too high, so that not only the workability such as stirring for mixing at the time of preparing the masking agent is deteriorated, but also the film forming property and printability of the prepared masking agent are remarkably inferior. It is.

Further, the solution for forming the functional film includes:
A solution containing a metal-organic compound, a metal-inorganic compound or a mixture thereof can be used. As the metal of the metal-organic compound, although not particularly specified, Ti,
It is preferable to select Si, Al, Zr or a composite metal thereof, and specific examples include titanium tetraisopropoxide, tetraethoxysilane, aluminum isobutoxide, and zirconium tetranormal butoxide. As the metal inorganic compound, cobalt nitrate, manganese nitrate, iron nitrate, copper nitrate, chromium nitrate, titanium tetrachloride, aluminum oxychloride and the like can be used. Further, oxide fine powders such as fumed silica, manganese-iron-copper composite oxide, copper-chromium-manganese composite oxide, and colloidal silica can be added to these solutions and dispersed. The particle size of the fine powder particles is preferably about 0.01 to 0.2 μm. Of these metal oxide fine particles, other metal oxides except fumed silica and colloidal silica are mainly used as a coloring agent. Further, as the solvent, ethanol, isopropanol, n-butanol and the like can be used.

Further, when removing the masking film, it is preferable to remove the masking agent by flowing water. Methods for forming a masking layer or a functional film on a substrate include known coating means, for example, a brush coating method, a roll coating method, a screen printing method, a spin coating method, a dipping method,
And so on.

[0017]

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

[0018]

EXAMPLES First, the following were used as raw materials for a masking agent. 1) Inorganic fine powder: Precipitable barium sulfate manufactured by Sakai Kagaku Co., Ltd. Finely divided silica "Aerosil" manufactured by Nippon Aerosil Co., Ltd. Cerium oxide "MIRAKE A" manufactured by Mitsui Mining & Smelting Co., Ltd. 2) Thickener: Daicel Chemical Co., Ltd. ) Nitrocellulose "FQRS-7" 3) Solvent: Ethyl carbitol manufactured by Kishida Chemical Co., Ltd. 3-methoxybutyl acetate manufactured by Tokyo Chemical Industry Co., Ltd. These are mixed and stirred as shown in Table 1 to prepare a masking agent. I mixed.

Next, a masking agent is screen-printed in a predetermined shape on a green plate glass substrate with a # 180 mesh tetron screen using a squeegee having a Shore hardness of HS70 to form a masking layer. The masking agent was dried by heating with a panel heater for about 1 minute.
In order to form a pattern having a relatively small area, low-cost local heating was employed. Therefore, the substrate was dried at about 100 ° C. so as not to cause thermal cracking or the like.

Next, isopropanol and n-butanol were added to titanium isopropoxide and sufficiently stirred to prepare an alkoxide solution. After immersing the glass plate substrate on which the masking layer was formed in this solution, 6 mm /
The film was gently pulled up at a constant speed of sec and baked in an electric furnace maintained at 450 ° C. for 6 minutes to form a functional film composed of a TiO 2 layer on a plate glass substrate.

The glass substrate on which the masking layer and the TiO 2 film were formed was washed and wiped with a flannel cloth, and the following items were evaluated. [Drying, curability] ＝= strongly bound. × = Weak binding. [Shielding Property of Masking Agent] ○ = Good shielding. ×
= The film-forming solution penetrates and is inferior in shielding properties.
[Removability of masking agent] ○ = Can be removed by light wiping. ×
= Requires considerable wiping and damages required membranes. [Pattern clarity] ＝= The pattern at the outline is clear. ×
= Peripheral bleeding.

As is clear from Table 1, good results were obtained within the range of the examples according to the present invention. On the other hand, in the comparative examples, the performance was poor in a plurality of items, and it was difficult to use as a masking agent.

[0023]

[Table 1]

[0024]

According to the present invention, the masking agent does not dry out even in long-time work and does not impair the printability, and when the masking agent is applied to the substrate by a simple method such as screen printing, the boundary contour is reduced. It is possible to form a desired pattern film with a clear part, and to obtain a wavelength-selective film such as an ultraviolet shielding film, an infrared shielding film, an electromagnetic shielding film, a coloring decoration film, and a multifunctional film having a wide variety thereof. It is suitable as a masking agent.

Claims (6)

[Claims] 1. A masking agent used for forming a pattern film having a predetermined shape on a substrate, comprising a fine inorganic powder, a cellulose resin for thickening and an organic solvent, wherein (inorganic fine powder) / (cellulose resin) ) Is 0.15
A masking agent characterized by having a solute concentration of from 5 to 2.30 and a combined solute concentration of the inorganic fine powder and the cellulosic resin of from 5 to 50% by weight. 2. The inorganic fine powder is at least one of finely divided silica, barium sulfate and cerium oxide.
The masking agent according to the above. 3. The cellulose-based resin is nitrocellulose and has a polymerization degree of H7 specified in JIS K6703,
The masking agent according to claim 1, which is at least one of H20, H60, H80, and H120. 4. The masking agent according to claim 1, wherein the organic solvent is at least one of ethyl carbitol, butyl carbitol, and 3-methoxybutyl acetate. 5. The masking agent according to claim 1, wherein the viscosity of the masking agent is 7 to 300 P (poise). 6. A method for forming a pattern film having a predetermined shape on a substrate, wherein a film is formed on a portion other than the pattern having the predetermined shape by using the masking agent according to claim 1 to form a masking layer. After drying at 250 ° C., a functional film is formed on the entire surface of the substrate by using a solution obtained by adding a solvent to a metal organic compound, a metal inorganic compound, or a mixture thereof.
A method for forming a patterned film, comprising, after firing at a temperature of 0 ° C. or more, removing the masking layer together with the functional film thereon.