JPH0649590B2 - Glaze composition for ceramics substrate - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION (Industrial field of application) The present invention relates to a thermal printer head (in the following text,
It is simply referred to as a head. The present invention relates to improvement of a glaze composition for a ceramic substrate used in (1).

(Prior Art) As a glaze composition for a conventional head, an expansion coefficient matched to the material of the substrate, electrically and chemically stable,
There has been a demand for good wetting with the substrate material, low thermal conductivity as well as heat resistance, and the like.

Therefore, research on the glass component forming the glaze layer has been widely conducted.

For example, in Japanese Patent Laid-Open No. 58-41738, there is a decrease in electrical insulation caused by alkali and lead in glaze with a composition that does not use alkali and lead (polymerization ratio indication ... The same unless otherwise specified). Solved SiO ₂ 44-5
_{8%, Al 2 O 3 6~12} %, CaO1~22%, Ba
A composition composed of O 6 to 38%, B ₂ O ₃ 1 to 6%, and ZnO 0 to 15% has been proposed.

Further, Japanese Patent Publication No. 62-15493 discloses a glaze for solving the problem of corrosion resistance to a solution of HF + HNO ₃ to which the glaze surface is exposed when wiring is mounted.
In molar ratio display, SiO ₂ 56-71%, BaO 15.5
To _28%, consists of _Al 2 O 3 6 to 16%, and the main component of the total amount of 83 to 99.8% or more, 10% or less of Sr
O, 8% or less of B ₂ O ₃ , 10% or less of CaO, 3% or less of MgO, and a total amount of the first subcomponent of 0.1 to 10%, and 4 % Or less Y
₂ O ₃ , 4% or less of La ₂ O ₃ , 6% or less of ZrO ₂ ,
1 selected from 6% or less of TiO ₂ and 3% or less of ZnO
A glaze composition has been proposed which comprises at least 100% of the second sub-ingredient, which is composed of at least one species and has a total content of 0.1 to 7%.

On the other hand, the inventor of the present application previously found that
No. 49 is SiO that does not contain B ₂ O _{3 and} has a thermal expansion coefficient matched to that of an alumina substrate and has heat resistance to withstand high temperature firing.
_{2 45~60%, Al 2 O 3} 5~12%, CaO5~1
5%, BaO 15-30%, SrO 0.5-5%, Ti
A glaze composition consisting of 0.5 to 5% O _{2 and} 0.5 to 5% MgO was developed and filed.

However, the market demands are diversifying more and more. For example, in the conventional partial glaze shape, the width of the printed line is about 0.7 mm, and the rise (the thickness is used in the same meaning below) is about 4.
The pattern was about 0 μm, but the width of the glaze pattern was set to about 0.55 in order to diversify the printing paper.
It was necessary to make the height of the film (mm) or less and the rise (film thickness) about 55 μm or more. Satisfying this need is not limited to the physical problems such as the wettability of the glaze with the alumina substrate at the time of high-temperature firing, the problem of the smoothness of the printed surface, etc. Chemical problems must also be resolved so that they do not change.

(Problems to be Solved by the Invention) The present invention considers the above-mentioned problems, that is, newly developed physical problems and chemical problems in order to develop glazes corresponding to new needs of users. As a result, the invention of the present application was completed.

(Means for Solving the Problem) In order to solve the above-mentioned problems, the present inventor repeatedly carried out a melting and printing test of a glaze composition to solve the above-mentioned problems, and provided the composition of the present invention. It was.

That is, in the present invention, the weight ratio of SiO _{2 is} 58 to 65%,
Al ₂ O ₃ 5-15%, CaO 8-25%, BaO
The glaze composition for a ceramic substrate is characterized by containing 1 to 20%, MgO 3 to 5%, and ZrO ₂ 2 to 4%.

In the present invention, regarding the problem of swelling of the printing surface,
While the conventional glaze has been focused on improving the wetting with the ceramic substrate, the present inventor has examined the opposite, that is, the direction of deteriorating the wetting. as a result,
Of the glaze components that affect the wetting angle between the ceramics substrate and the glaze, the components that increase the angle in order are listed below. The following equation was used. The above problem was solved by finding ZrO ₂ , which is a component that deteriorates wetting with ceramics, and using it.

Ba>Mg> Ca Next, the reasons for limiting the content of each component will be described. SiO ₂
Is a component forming the center of the glass structure. If it is 65% or more, the expansion coefficient becomes too small, and if it is 58% or less, the heat resistance becomes insufficient.

Al ₂ O ₃ is a component used to prevent devitrification of glass, is effective in the range of 5 to 15%, and has no effect outside the range.

CaO is a component used as a fluxing agent, and its action is insufficient at 8% or less and crystallizes at 25% or more.

BaO and MgO are both components used as a flux, but as shown in the above formula, they are selected and used from other physical and chemical properties, and are desirable in a range other than the range limited in the present application. No results are obtained.

As described above, ZrO ₂ is an important component that deteriorates the wetting of ceramics and glazes and achieves the object of the present invention. If it is 2% or less, it has no effect, and if it is 4% or more, melting becomes difficult.

(Function) The glaze composition of the present invention having the above composition,
It has high heat resistance and reaches a yield point of 820 ° C. Therefore,
When it is used for a thermal head, the glaze layer has high heat resistance during high temperature firing for forming a circuit, and does not cause modification of the circuit pattern. In addition, as described above, it was possible to obtain the intended glaze pattern having a width of about 0.55 mm or less and a rise (film thickness) of about 55 μm or more.

Examples of the present invention will be shown below to clarify the present invention.

(Example) Raw materials were prepared so as to have the oxidizing composition shown in Table 1 on the next page, placed in an alumina-based high-purity crucible, and 1400 to 15
The glass obtained by melting at 00 ° C. and quenching was pulverized with an alumina ball mill. The fine glass powder was mixed with a vehicle that was a mixture of ethyl cellulose and α-terpinol to give a paste.

This paste is printed in a desired shape on an alumina substrate by a screen printing method, baked at 1200 to 1300 ° C.,
A glaze substrate was obtained.

As shown in the evaluation column of Table 1, the result was that only Example 4 was acceptable and the others were unacceptable.

The physical properties, softening point (° C.), and yield point (° C.) of the glass whose composition is shown in Table 1 were all as shown in the same table.

(Effect of the invention) As is apparent from the above description, the present invention is a glass composition for glaze, which has not been hitherto known, and has a narrow print pattern and a large ridge (film thickness) on the print surface. When used as a glaze for a glazed substrate, particularly in a head for a word processor, it is effective in diversifying printing paper.

Claims (1)

[Claims] 1. A weight ratio of SiO ₂ 58 to 65%, Al ₂ O
_{3 5~15%, CaO8~25%, BaO1~20} %,
A glaze composition for a ceramic substrate, containing ₃ to 5% of MgO and _{2 to} 4% of ZrO ₂ .