JPH0574536B2 - - Google Patents

Description

[Detailed description of the invention]

Industrial Application Field The present invention is directed to a new ceramic color composition that can prevent silver ion migration. More specifically, when molding vehicle window glass, etc., ceramic color paste and silver paste are overprinted and fired at the same time. The present invention relates to a ceramic color composition that can reliably prevent migration (diffusion/movement) of upper layer silver into a ceramic color. Conventional technology and its problems Recently, vehicle window glasses, including windshields, side glasses, and rear glasses, are usually attached directly to the car body using an organic adhesive, which prevents photoaging of the adhesive. For the purpose of preventing the adhesive from spilling out or concealing the adhesive from spilling out, a paste of a ceramic color composition consisting of PbO-SiO ₂ -B ₂ O _3- based glass frit and a heat-resistant inorganic pigment is baked and painted around the glass. , a means of applying a ceramic color of black or dark gray is commonly used. More specifically, the above paste is first screen printed on a flat glass plate before being reinforced, and then the paste is printed with a thickness of approximately 550~
It is constructed by heating the glass to 750°C and simultaneously strengthening and shaping the glass and baking the ceramic color. However, especially on the rear glass, silver paste is baked on as a heat-generating material to prevent fogging, and the electrode forming part (busbar part) overlaps with the ceramic color baking part. However, in the past, when ceramic color paste and silver paste were overprinted and baked on such base glass, silver ions migrated through the ceramic color, and some of the silver ions migrated between the base glass and the ceramic color. It is well known that it reaches the interface by diffusion and migration and develops an amber color. The color development due to the migration of silver ions is particularly severe on the bottom surface (tin surface) of the plate glass, and such color development not only impairs the concealing effect, which is the original purpose of painting and baking the ceramic color, but also This makes the existence of the electrode portion formed by paste baking even more noticeable, and has the serious disadvantage of significantly impairing the appearance of the window glass attached to the car body from the outside of the car. In addition, the color development due to the migration of silver ions is not limited to amber color, but may also exhibit a color tone such as blue, green, or a mixture thereof. In more extreme cases, the silver ions that have reached the interface It may further move and diffuse laterally across the surface of the base glass, causing blue coloring not only in the electrode area but also in its surroundings. Furthermore, when a terminal electrode is installed on the silver obtained by overlaying and baking a silver paste on the ceramic color to generate heat from the silver, if the migration occurs, the adhesion between the silver and the solder becomes extremely poor. There is also the negative effect of a decline. Currently, no means have been developed to proactively solve the problems associated with the migration of silver ions as described above, but there is only a method of passively removing the silver busbar part from the ceramic color part and baking it. It's just that they are being taught. However, adopting this method has the disadvantage that the visibility through the rear window of the vehicle is narrowed, the terminal lead wires can be seen from outside the vehicle, and the appearance is impaired.
This does not solve the above problem in any way. Problems to be Solved by the Invention The purpose of the present invention is to eliminate all the problems of the conventional ceramic color applied to vehicle windshields, and in particular to create a new ceramic color composition that does not cause migration of silver ions. It's about providing things. The present inventors have conducted extensive research for the above purpose, and in the process, they came up with the idea that the above migration could be prevented by preventing the generation of silver ions themselves.Based on this idea, the conventionally widely used Research has been carried out to change the composition of the ceramic color composition itself so that it does not promote the ionization of metallic silver at the baking temperature, but on the contrary can reduce silver ions to metallic silver. the result,
When a specific alkali-free glass is selected as the frit constituting the composition, and when a predetermined amount of a certain metal or its alloy is added to the composition, the resulting composition is not as strong as the composition during baking coating. It was discovered that even when the frit inside the ceramic color has a decreased viscosity, the metallic silver present in the upper layer of the ceramic color does not substantially cause migration due to ionization, and the present invention has now been completed. . Means for Solving the Problems That is, the present invention consists of approximately 40 to 90% by weight of an alkali-free low melting point glass powder containing no alkaline components consisting of K ₂ O, Na ₂ O and Li ₂ O, and 0 to 90% by weight of a heat-resistant inorganic pigment. about 40
The present invention relates to a ceramic color composition comprising approximately 1 to 30% by weight of a powder of a metal baser than silver and its alloy, and capable of preventing migration of silver ions. Based on the above configuration, the ceramic color composition of the present invention has the advantage that even if it is printed on a vehicle window glass in the form of a paste and overlaid with a silver paste, and then fired, there is no migration of the upper layer silver into the ceramic color. Therefore, it completely suppresses amber color and other colors at the interface between the vehicle base glass and the ceramic color, thereby achieving the concealing effect that is the original purpose of painting and baking the ceramic color. It can be displayed beautifully, and there is no risk of damaging the appearance from the outside of the vehicle.
Further, the vehicle window glass to which the composition of the present invention is applied does not have the disadvantage of reduced adhesion between silver and solder when a terminal electrode is installed thereon. The alkali-free low melting point glass powder constituting the composition of the present invention is alkali-free, that is, K ₂ O, Na ₂ O
The melting point, particle size, etc. may be the same as those conventionally used as this type of glass frit, provided that it does not contain an alkali component consisting of Li 2 O and Li ₂ O. Further, its composition is not particularly limited as long as it is alkali-free, and may be the same as known ones belonging to this type of glass frit. A typical example thereof is PbO--SiO ₂ --B ₂ O ₃ -based glass frit. This is usually PbO40-70% (wt%,
(same below), SiO ₂ 20-40% and B ₂ O ₃ 5-15% as the basic composition, and R ¹ O ₂ (TiO ₂ ,
ZrO ₂ , SnO ₂ etc.), R ² O (ZnO, CaO, BaO,
At least one component selected from CdO, etc.), R ³ ₂ O ₃ (A ₂ O _3, etc.), etc. can also be optionally added and blended. Generally, the amounts of the above-mentioned optional components that can be blended are suitably selected within the range of about 1 to 15% in total. The above-mentioned alkali-free low melting point glass powder is present in the composition of the present invention in an amount of about 40 to 90% by weight, preferably about 50 to 80%.
It is blended within the range of. If this is less than the above range, it becomes increasingly difficult to sufficiently wet (baking) the other components constituting the composition of the present invention, that is, heat-resistant inorganic pigments and powders of metals baser than silver and their alloys. There is a risk that baking will not be possible during construction. On the other hand, if the content exceeds the above range, the amount of other components constituting the composition of the present invention will decrease accordingly, making it difficult to exhibit the desired migration prevention effect. The heat-resistant inorganic pigment constituting the composition of the present invention may be the same as that used in conventional ceramic color compositions of this type. As a specific example,
For example, CuO・Cr ₂ O ₃ (black), CoO・Cr ₂ O ₃ (black), Fe ₂ O ₃ (brown), TiO ₂ (white),
CoO・A ₂ O ₃ (blue), CdS・αCdSe (maron~
(yellow), NiO.Cr ₂ O ₃ (green), etc. Although they do not impart color tone, conventionally used fillers such as alumina, silica, and zirconium silicate can also be included in the inorganic pigments. The blending ratio of the heat-resistant inorganic pigment can also be arbitrarily selected within a range of up to 40%, and is not different from conventional ones. In addition, it is important that the composition of the present invention contains a predetermined amount of powder of a metal baser than silver and its alloy as an essential component, together with the above-mentioned alkali-free low melting point glass powder and heat-resistant inorganic pigment. The migration prevention effect intended by the present invention can be achieved. The components include, for example, Al, Zn, Fe,
Includes alloy powders such as Ni, Sn, Pb, Cu and the like. All of these can achieve the desired effect of the present invention depending on their combination, but among them, Sn
Cu and its alloys tend to slightly increase the baking temperature of the entire ceramic color, Cu and its alloys tend to cause cut staining on the bottom surface of the glass substrate and make the color reddish, and Fe has a tendency to cause reddish-brown color due to its oxide. Therefore, if the ceramic color is black or dark gray, it tends to have a strong reddish tone. For these, Al, Zn,
Ni, Pb, etc. are most preferable in this respect because they do not pose a risk of changing the color tone or baking temperature of the ceramic color itself. Powders of these metals are easily available with particle sizes of 10 μm or less, and commercially available products with such particle sizes can be suitably used in the present invention. However, although this particle size is not particularly limited, if it is too large, there is a risk of clogging when the composition is used as a paste for screen printing, which is undesirable. The powders of the metals and alloys thereof may be used alone or in combination of two or more. The amount incorporated into the composition is preferably selected from the range of about 1 to 30%, preferably about 5 to 20%, and if it is less than this range, the migration prevention effect of the addition is sufficient. If a large amount is added beyond the above range,
The baking temperature of the resulting composition gradually increases, and baking may become extremely difficult, both of which are undesirable. The ceramic color composition of the present invention is prepared in the same manner as conventional ceramic color compositions of this type by mixing predetermined amounts of the above-mentioned three components, and then similarly formed into a paste form and applied to base glass. In more detail, the above paste may be, for example, 3 above.
It is prepared by adding about 15-25% by weight of an oil vehicle to about 75-85% by weight of a mixed powder of the ingredients, kneading, and finally passing through three rolls to thoroughly disperse the solids in the vehicle. Examples of the oil-based vehicle used here include ordinary ones, such as pine oil, α-terpineol, butyl carbitol, butyl carbitate acetate, etc., in which a resin such as ethyl cellulose or polybutyl methacrylate is dissolved. I can do it. In addition, an ultraviolet curable vehicle mainly composed of acrylate or methacrylate oligomers can also be suitably used in the same manner as above. The paste of the ceramic color composition of the present invention prepared in this way is applied to a base glass according to a conventional method, typically by screen printing, and then applied to a base glass in a manner of approx.
Baking is performed at 550 to 750°C, but the above-mentioned construction means and baking temperature are not particularly limited, and various conventionally known methods other than the above can be used. Examples Examples will be given below to explain the present invention in more detail. In each example, % indicates weight %. Example 1 A frit powder having the following composition and particle size distribution is used as an alkali-free low melting point glass powder. Frit composition Particle size distribution P60 60% 5 μm or less 75% SiO ₂ 30% 5-10 μm 20% B ₂ O ₃ 8% 10-15 μm 5% TiO ₂ 1% A ₂ O ₃ 1% 70% of the above frit powder, zinc metal powder The ceramic of the present invention is prepared by mixing 10% of F-2000 (manufactured by Honjo Chemical Co., Ltd.), 15% of black pigment (#9510, manufactured by Dainichiseika Kogyo Co., Ltd.), and 5% of white pigment (manufactured by Ishihara Sangyo Co., Ltd., R-550). A color composition was obtained. 80% of the ceramic color composition obtained above,
A ceramic color paste was prepared by adding 20% of a vehicle in which 10% ethyl cellulose was previously dissolved in α-terpineol and kneading, and passing through three rolls to uniformly disperse the solid content. This is called "Paste A". Example 2 67% of the same frit powder as in Example 1, 8% of nickel powder [SNP-050, manufactured by Sumitomo Metal Mining Co., Ltd.], 20% of black pigment [manufactured by Asahi Chemical Industries, Ltd., #3052], and 20% of white pigment [Teikoku Chemical Co., Ltd.] A ceramic color composition of the present invention was obtained by mixing 5% of JA-1 (manufactured by Co., Ltd.). A ceramic color paste was prepared in the same manner as in the second half of Example 1 using 80% of the composition. This is called "Paste B". Examples 3 to 5 In place of the zinc metal powder in Example 1, 10% of each metal powder shown in Table 1 below was used,
Similarly, a ceramic color composition of the present invention was obtained,
Ceramic color pastes (Paste C to Paste E) were also prepared in the same manner using each of the obtained compositions.
was prepared.

[Table] Comparative Example 1 80% of the frit powder obtained in Example 1, 15% of black pigment [manufactured by Dainichiseika Kagyo Co., Ltd., #9510] and 5% of white pigment [manufactured by Ishihara Sangyo Co., Ltd., R-550] were mixed. A comparative ceramic color composition was obtained. A comparative ceramic color paste was prepared in the same manner as in the second half of Example 1 using 80% of the composition. This will be referred to as "comparison paste a." Comparative Example 2 A frit powder (alkaline low melting point glass powder) having the following composition was used: 70% of the frit powder, 10% of zinc metal powder (F-2000, manufactured by Honjo Chemical Co., Ltd.), and black pigment (manufactured by Dainichiseika Chemical Co., Ltd.). #9510] 15% and a white pigment (manufactured by Ishihara Sangyo Co., Ltd., R-550) 5% were mixed to obtain a comparative ceramic color composition. Fritt composition PbO 51.0% SiO ₂ 34.0% B ₂ O ₃ 4.0% ZrO ₂ 4.0% TiO ₂ 2.0% Li ₂ O 3.0% Na ₂ O 2.0% Using 80% of the obtained composition, the second half of Example 1 and A comparative ceramic color paste was prepared in the same manner. This will be referred to as "comparison paste b". Silver ion migration prevention test The following tests were conducted using each of the pastes obtained in the above examples and comparative examples. That is, each paste was printed on the bottom surface of a plate glass, and after preliminary drying at 150°C for 5 minutes, silver paste was printed on top of this paste, and the resulting sample was placed in a firing furnace at 650°C and dried for 3 minutes. Heat for 30 seconds to bake. At this time, if there is migration of silver ions, visual inspection from the unprinted surface reveals that only the silver printed area is colored from deep amber to blue-green depending on the degree of migration. is confirmed. Based on the above visual observation results, migration of silver ions is determined according to the following criteria. ◎...No coloration is observed. △...Blue-green coloration is observed. ×...Amber coloring is observed. Further, regarding the sample prepared above, molten solder was placed on the silver part, and the adhesion of the solder was judged according to the following criteria. ◎...Solder spreads sufficiently. △……There is solder on some parts. ×...No solder applied at all. The results obtained from the above test are shown in Table 2.

【table】

[Table] From Table 2 above, it can be seen that by applying the paste using the composition of the present invention, migration of silver ions can be reliably prevented, and the solderability to the silver parts is also good. .

Claims (1)

[Claims] 1. Alkali-free low melting point glass powder containing no alkaline components, consisting of K ₂ O, Na ₂ O and Li ₂ O, approximately 40~
90% by weight of a heat-resistant inorganic pigment, 0 to about 40% by weight of a heat-resistant inorganic pigment, and about 1 to 30% by weight of a powder of a metal baser than silver or its alloy, and is characterized by being able to prevent migration of silver ions. .