JPH08259258A - Leadless glass composition - Google Patents

Abstract

PURPOSE: To impart a leadless safe compsn. not retarding color forming by a pigment and to improve chemical resistance and peeling resistance. CONSTITUTION: This leadless glass compsn. is an Li2 O-Al2 O3 -SiO2 glass compsn. consisting of, by weight, 45.0-60.0% SiO2 , 4.0-18.0% Al2 O3 , 5.0-10.0%, in total, of alkali metal oxides including >=2.0% Li2 O, 15.0-30.0% B2 O3 and 3.0-7.0% ZrO2 . The weight ratio of Al2 O3 to Li2 O is >=1.2 and the softening point of the compsn. is 700-760 deg.C.

Description

Detailed Description of the Invention

[0001]

The present invention does not contain a lead component,
It relates to a hygienically safe glass composition. More specifically, the present invention relates to a glass composition that is suitably used as a glaze, an enamel, a painting material, etc. as a decorative material for ceramic products.

[0002]

2. Description of the Related Art Ceramic products such as pottery, porcelain and enamel are decorated with glaze, enamel and decorative paint.
Here, the enamel and the glaze are mainly composed of glass frit, and the decorative paint is mainly composed of pigment and flux (glass frit). Heretofore, these glass components have contained lead (mainly PbO) because they have improved gloss and translucency, and have improved color tone when pigments are added.

However, in recent years, from the viewpoint of lead toxicity, lead elution standard values have been strictly regulated, especially in the United States, and lead-free glass compositions have been actively developed.
Many suggestions have been made.

Among them, there are JP-A-48-102813 and JP-A-5-270860. JP 48-102813
Patent Publication No., K ₂ O: 0~31.5% (wt%, hereinafter the _{same), Na 2 O: 0~31.5%} , Li 2 O: 0~14.
1%, CaO: 0-44.0%, MgO: 0-22.0
%, ZnO: 0 to 10.0%, BaO: 0 to 22.0
%, Al ₂ O ₃ 0-10.0%, B ₂ O ₃ : 13.0-4
4.8%, Bi ₂ O ₃ : 0 to 25.0%, SiO ₂ : 1
A coloring material is added to the frit obtained by combining all the raw materials included in the composition range of 8.3 to 80.0% and ZrO ₂ : 0 to 6.0%, and a Japanese paint for ceramics is mainly used in the form of all frit. And other lead-free compositions for use as other paints and glazes.

JP-A-5-270860 discloses that Li ₂ O: 0
12% (wt%, same below), MgO: 0-10%, C
_{aO: 3~18%, B 2 O} 3: 5~25%, Al 2 O 3: 3
_{~18%, Na 2 O: 3~18} %, K 2 O: 3~18%,
BaO: 0 to 12%, SiO ₂ : 25 to 55%, Ti
O ₂ : 0 to 5%, ZrO ₂ : 0 to <3% glass composition,
Contains less than 30% by weight of pigment and has a coefficient of thermal expansion of 5.0 × 1.
It relates to a glass composition which is less than 0 ^-6 / K. Further, the glaze formed from this glass composition has a transition temperature of 300 to 510 ° C., a softening temperature of 400 to 610 ° C., 430 to 84.
Processing temperature of 0 ° C., and 9.20 to 16.40 × 10 ⁻⁶ /
It has a coefficient of thermal expansion of K.

[0006]

In the conventional lead-free glass composition, the color development when mixed with the pigment was insufficient, and the color tone did not appear clearly. In particular, there was a problem in coloring the blue pigment. In addition, JP-A-48-102813 and JP-A-
The glass composition described in JP-A 5-270860 has a softening point of 60.
It is low in the range of 0 ° C or lower, and cannot be welded at high temperatures of 1000 ° C or higher and flows downward, so it is not suitable as a flux for painting materials for in-glaze decoration that requires re-baking at high temperatures. Met.

Therefore, the present invention is a glass composition which does not contain lead at all and is sanitary and safe, and which can be widely applied to on-glaze decorations and in-glaze decorations, glazes, enamel and other decorative materials in general. It is an object of the present invention to provide a glass composition which has excellent properties, peeling resistance, and glossiness, and further exhibits a vivid color tone without hindering the color development of the pigment, and particularly excellently develops a blue color. Further, it is an object of the present invention to provide a painting material which is lead-free, hygienic and safe, and has a clear color tone by using this as a flux component. In particular, it is intended to provide a painting material that vividly develops a blue color.

[0008]

Means for Solving the Problems The inventors of the present invention have made extensive studies in accordance with the above-mentioned object, and as a result, a Li ₂ O—Al ₂ O ₃ —SiO ₂ -based glass composition having a predetermined compounding relationship has the above object. The inventors have found that the above can be achieved and completed the present invention.

That is, according to the present invention, SiO ₂ 45.0-6
0.0 wt%, Al ₂ O ₃ 4.0 to 18.0 wt%, alkali metal oxides in total 5.0 to 10.0 wt% (however, Li ₂ O 2.0 wt% or more), B ₂ O ₃ 15.0-3
A Li ₂ O—Al ₂ O ₃ —SiO ₂ -based lead-free glass composition consisting of 0.0 wt% and ZrO ₂ 3.0 to 7.0 wt% (total 100 wt%), wherein Al _{2 in} ratio
O ₃ / Li ₂ O is 1.2 or more and the softening point is 700 to 7
It relates to a lead-free glass composition which is in the range of 60 ° C.

It is preferable that the glass composition of the present invention further contains ZnO in an amount of more than 0% by weight and not more than 14.0% by weight since the fusion property with the base material is improved. The amount of ZnO is preferably 2.0 to 10.0% by weight. Further, from the viewpoint of adjusting hardness or viscosity, 0 to 6.0% by weight of CaO and / or 0 to 4.0% by weight of MgO can be added. Further, from the viewpoint of adjusting the softening point and the thermal expansion coefficient α of the glass composition, relative to the total weight,
It is preferable that the alkali metal oxide is composed of 2.0 to 5.0 wt% of Li ₂ O, 0 to 6.0 wt% of Na ₂ O, and 0 to 2.0 wt% of K ₂ O. In particular, the coefficient of thermal expansion α
The glass composition adjusted to 92.0 × 10 ⁻⁷ or less, particularly 70.0 × 10 ⁻⁷ or less does not cause peeling or penetration and is suitably used as a decorative material.

Furthermore, the present invention relates to a lead-free painting material using the above-mentioned glass composition as a flux component, and in particular, the color development of a blue pigment can be vividly exhibited.

[0012]

Although SiO ₂ is a main constituent for glass formation, the glass composition of the present invention is characterized by containing a large amount of SiO ₂ as compared with the conventional lead-free glass composition.

Lead and cadmium have the effect of significantly reducing the melting temperature of the glass composition. On the other hand, SiO
₂ has the effect of raising the melting temperature. Therefore, in the conventional glass composition containing no lead, a low softening point is required particularly for use in a decorative material.
The blending amount of SiO ₂ was naturally limited, and in most cases it was 40% by weight or less, vitrification was not sufficient, and coloring of the pigment did not appear clearly.

In the present invention, although the SiO ₂ is blended in a large amount of 45% by weight or more, it is possible to reduce the melting point by specifying the blending amounts of the alkali metal oxide and B ₂ O ₃ which are the melting agents. It has become possible to provide a glass composition that can realize a complete glass phase by firing at low temperature.

A lead-free glass composition containing 40% by weight or more of SiO ₂ is disclosed in JP-A-48-102813,
It is proposed in JP-A-5-270860. However, only 40% by weight or less is described in the examples of JP-A-48-102813, and it cannot be said that a glass composition substantially exceeding 40% by weight is disclosed.
Further, as described above, all of the glass compositions described in these publications are still unsatisfactory in the color development when mixed with a pigment, particularly the blue color development. Further, it has a low softening point and is not suitable as a flux for painting materials for in-glaze decoration which requires re-baking at high temperature.

Not only the above-mentioned publications, but also conventional Co-Al (blue) decorative materials for coloring are inferior in color developability, weak in acid resistance, and easily discolored or decolorized. On the other hand, the glass composition of the present invention is capable of producing a faithful aqua blue color, which is the original color of the pigment to be mixed, is lead-free, and has sufficient assurance including acid resistance. It is an excellent thing to secure.

The lead-free glass composition of the present invention comprises Li ₂ O
-Al ₂ O ₃ -SiO ₂ system and SiO ₂ is 45.0 to 6
Contains 0.0% by weight. When the SiO ₂ content is less than 45% by weight, the color tone becomes thin or dull, and the water resistance and chemical resistance are poor. Preferred is a glass composition containing more than 50% by weight. On the other hand, if it exceeds 60% by weight, the melting temperature of the entire composition becomes high,
It is not suitable because the firing temperature is higher than the softening point of the glaze.

Al ₂ O ₃ is contained in an amount of 4.0 to 18.0% by weight, and has the function of adjusting the fluidity of the melt and maintaining the stability at the time of welding. It is particularly preferable that the content is 10.0 to 16.0% by weight. If Al ₂ O ₃ is less than 4% by weight, it will not adhere to the base material in a uniform thickness and will flow downward during firing.
On the other hand, if it is blended in excess of 18% by weight, it is not suitable because it has poor chemical durability.

Alkali is a strong melting agent, and since it lowers the melting temperature, increases the fluidity of the glass composition, and accelerates color development, a total of 5.0 to 10.
Must be compounded at 0% by weight. If it is less than 5.0% by weight, vitrification is insufficient and the coloring of the pigment is hindered. On the contrary, if it is blended in excess of 10.0% by weight, it may cause penetration.

Among them, Li ₂ O has an action of improving chemical durability, particularly acid resistance, and vividly coloring the pigment, so that Li ₂ O must be blended essentially (at least 2.0% by weight). Furthermore, the Al ₂ O ₃ / Li ₂ O ratio must be 1.2 or higher. When Al ₂ O ₃ / Li ₂ O is blended in a range of less than 1.2, the color of the pigment mixed with the glass composition of the present invention is insufficient and the color tone is impaired, which is not suitable. The higher the Al ₂ O ₃ / Li ₂ O ratio, the better the color development of the pigment, especially the color development of the cobalt-based pigment.

Li ₂ O is preferably added in an amount of about 2.0 to 5.0% by weight (more preferably 4.0 to 5.0% by weight). If it is less than this range, the gloss and chemical durability are poor, and if it is too large, the glass is rather devitrified and the color tone is impaired.
Examples of other alkali metal oxides include Na ₂ O and K ₂ O. Na ₂ O is about 0 to 6.0% by weight (further 1.0 to 3.0% by weight), K ₂ O. Is preferably mixed in an amount of about 0 to 2.0% by weight (further 1.0 to 2.0% by weight).

The lead-free vitrification composition of the present invention further comprises 3.0-7.0 wt% (preferably 5.0-6.0 wt%) ZrO ₂ and 15.0-30.0 wt%. (preferably 18.0 to 23.0 wt%) containing B ₂ O ₃ in. B ₂
O ₃ acts as a solvent and also increases gloss. B ₂ O ₃
If it is less than the above range, vitrification is insufficient, and if it is blended too much, the pigment coloring, especially red and green coloring, is hindered. Addition of ZrO ₂ imparts chemical durability, especially alkali resistance. If the ZrO ₂ content is less than the above range, the chemical durability will be poor, and if it is too large, the viscosity and softening point of the glass will increase, which is not suitable.

The lead-free glass composition of the present invention further comprises ZnO.
Is preferably blended from the viewpoint of improving color developability and glossiness, increasing strength, and improving fusion property with the substrate. However, if it is blended in an amount of more than 14.0% by weight, the gloss and the chemical durability are inferior, which is not suitable. Also, 1.0
If it is less than 10% by weight, the effect of the above ZnO compounding does not clearly appear, so 1.0 to 14.0% by weight is preferable,
It is more preferably about 2.0 to 10.0% by weight (further, 4.0 to 8.0% by weight).

The glass composition of the present invention may further contain MgO and CaO, if desired. Addition of CaO increases the hardness, that is, the wear resistance. MgO has the function of adjusting the viscosity, but if too much is mixed, it will devitrify,
Impair the color tone. The preferable addition amount of MgO is 0 to 5.
0% by weight (more preferably 0 to 3.0% by weight), CaO
Is 0 to 7.0% by weight (more preferably 0 to 5.0% by weight). In either case, if the amount is more than the above range, the chemical durability becomes poor, which is not preferable.

The lead-free glass composition of the present invention can be adjusted appropriately within the range of the composition of the present invention to adjust the coefficient of thermal expansion to a desired value. For example, when used as a flux for painting materials, the thermal expansion coefficient α should be 92.0 × 10 ^-7 or less when applying inglaze decoration from the viewpoint of preventing peeling of the decoration when firing. Is preferred, and 70.0 x 1 for on-glaze decoration
It is preferable to adjust the composition so as to be 0 ⁻⁷ or less.
The same applies when used as a glass frit for enamel or glaze or enamel for glass having a very small coefficient of thermal expansion of the base material.

The component that lowers the coefficient of thermal expansion is K
₂ O, Li ₂ O, ZnO, CaO, MgO, B ₂ O ₃ (however, it increases when compounded in a large amount) and the like, and conversely, Na ₂ O is a component that increases the thermal expansion coefficient. By adjusting the blending amount within the range of the composition of the present invention, a desired thermal expansion coefficient α can be obtained.

The inventors of the present invention actually produced a glass composition of the present invention as a prototype and investigated the coefficient of thermal expansion. As a result, within the scope of the present invention, the total content of oxides of alkaline earth metals was further calculated. When adjusting within the range of 0 to 16.0% by weight,
The value of α was 92.0 × 10 ⁻⁷ or less, and particularly 70.0 × 10 ⁻⁷ or less.

The lead-free glass composition of the present invention has a softening point in the range of 700 to 760 ° C.

[0029]

Preferred Embodiments Therefore, the softening point of the lead-free glass composition of the present invention is within a range adjusted to a suitably low temperature side, and therefore enamel or low-grade glaze, for on-glaze decoration which requires low-temperature firing. It can be used over a wide range as a decorative material for ceramic products such as pottery, porcelain and enamelware, as well as a decorative material for decorative glaze that requires re-baking at high temperature from decorative material, resistance to chemicals, It has excellent resistance to peeling, and when it is mixed with a pigment and baked, it can be vividly colored without impairing the color tone of the pigment. The pigment content is about 30% by weight or less, preferably about 10 to 30% by weight, based on the total weight of the decorative material.

The glass composition of the present invention can be used in the same manner as the conventional enamel or low-glaze glass frit or the flux of the painting material.

For example, when the composition is used as a flux for a painting material, the composition is poured into a preheated glass crucible to be melted, and when the composition is melted uniformly and bubbles are eliminated, the composition is poured into water and rapidly cooled. Use crushed, sized and dried. The painting material is a mixture of the flux according to the present invention and a pigment up to about 30% of the total weight, and if necessary, glycerin, turpentine oil, fatty oil, balsams,
It is prepared by adding glue or the like. Coloring is performed by hand-painting the thus-prepared painting material with a brush or a brush, as well as by transfer paper or direct printing.

When the on-glaze decoration is applied after the above-mentioned decoration is applied to the glazed base, it is about 800 to 900.
Approximately 1 when baked at about ℃ and decorated with in-glaze
Bake at about 000 to 1300 ° C. In order to prevent peeling of the decorative decoration, the coefficient of thermal expansion of the glass composition of the present invention should be adjusted to about the same as or lower than that of the glaze. ^-7 or less is preferable, and 70.0 when performing on-glaze decoration
It is desired to adjust the composition so as to be 10 ⁷ or less.

When the glass composition of the present invention is used as a glaze, the fields in which enamel or low-grade glaze is used,
For example, it is applied to glazes for glass, enamel, etc., and can be used in the same manner as conventional glass frits. That is, it is homogenously melted and then pulverized by a wet or dry method, to which water or an oil medium and, if necessary, a pigment are added, and a peptizer,
Add additives such as flocculants as appropriate to make sludge, soak it,
It is glazed by brushing, spraying, shaping, etc.
The firing is performed at about 700 to 900 ° C, preferably around 800 ° C. The thermal expansion coefficient of the glass composition of the present invention,
It needs to be adjusted to about the same level as or lower than that of the base material, preferably 92.0 × 10 ^-7 or less, and more preferably 70.0 × 10 ^-7 or less.

As a result of X-ray diffraction analysis and the like of the fired glass composition of the present invention, no crystals were observed and it was confirmed that a perfect glass phase was formed.

[0035]

EXAMPLES Next, the present invention will be described in more detail with reference to examples. However, the present invention is not limited to these examples.

<Examples 1 to 16> A glass having the composition shown in Table 1 below was used as a flux component, and a blue pigment (Co-Al
30% by weight of (system) was mixed to prepare a decorative paint. Using this paint, a glazed base material having a composition shown in Table 3 was decorated, baked at 800 to 900 ° C, and subjected to on-glaze decoration. As a reference, Table 2 shows the softening properties of some of the glass fluxes of the above-mentioned examples.

<Example 17> A glass having the composition shown in Table 1 below was used as a flux component to prepare a decorative paint in the same manner as in Example 1 above.
It was fired at 00 ° C. and decorated with in-glaze. Table 2 shows the softening properties of the glass flux of this example.

[0038]

[Table 1]

[0039]

[Table 2]

[0040]

[Table 3]

<Evaluation Test> The decorative pottery obtained in each of the above examples was subjected to an evaluation test regarding color tone, chemical resistance and peeling resistance. The results are shown in Table 4, and the decoration applied using the glass composition of the present invention was vividly colored without impairing the color tone of the pigment, and was excellent in chemical resistance and peeling resistance. The details of the evaluation test method will be described later.

[0042]

[Table 4]

(Color tone test) Measured with a Lab color difference meter to obtain L
When the value, the value of a, and the value of b were within the range of the standard value, they were regarded as acceptable. The range of the reference value was set in consideration of the one that looks blue-green visually and the value measured by the Lab color difference meter. Reference value: L value = 25 to 31, a value = 13 to 17, b value =
58-70

(Chemical resistance test) Acid solution, alkaline solution,
The detergent solution and the hot water were immersed under the conditions shown in Table 5, and then the degree to which the decorative surface was corroded was observed, and a pass / fail judgment was made according to the following evaluation criteria.

Acceptance Criteria: Acid Solution: No change compared with the control product (not immersed in the acid solution). Alkaline solution: Wipe the decorative surface with a cloth to prevent color loss. Detergent solution: Wipe the decorative surface with a cloth and the color will not fall off. Hot water: Wipe the decorative surface with a cloth and the color will not fall off.

[0046]

[Table 5]

(Peeling resistance test) The following three types of tests were conducted.
A test in which no peeling or penetration was observed in all the tests was regarded as a pass.

(1) Peeling test after firing After firing, adhesion with a transparent cellophane tape to the decorative surface,
Peeling is defined as 1 cycle, and this cycle is repeated 5 times to check whether there is peeling on the decorative surface.

(2) Penetration Confirmation Test Fluorescent paint is applied to the decorative surface, dried for 5 minutes, and the paint is wiped off. If there is penetration, residual fluorescent paint that has soaked in is observed.

(3) Cold heat test After the decorative dish was subjected to a cold heat test of ΔT = 160 ° C. (hot water ← → cold water) for 5 cycles, the above tests (1) and (2) were carried out to check for peeling and penetration. To confirm.

<Comparative Example> Using the glass having the composition shown in Tables 6 and 7 as the flux component, a blue paint was prepared in the same manner as in the example. This paint was used to decorate the same glazed substrate as that used in the examples, and it was fired at 800 to 900 ° C. to give an on-glaze decoration. The above-described evaluation test was performed on the decorative pottery thus obtained in the same manner as in the examples. The results are as shown in Tables 6 and 7.

[0052]

[Table 6]

[0053]

[Table 7]

When the value of Al ₂ O ₃ / Li ₂ O in the flux composition was 1.2 or less, the coloring of the pigment was impaired and a clear color tone was not obtained (Comparative Examples 1-1 to 1-1). See 1-11). Further, when the compounding amounts of SiO ₂ , Al ₂ O ₃ and ZnO were out of the range of the present invention, the decorative surface was inferior in chemical durability (see Comparative Examples 2-1 to 2-10). Further, when the on-glaze decoration is applied, when the coefficient of thermal expansion of the flux component is larger than 7.0 × 10 ⁻⁷ , peeling or penetration was observed on the decorative surface (Comparative Examples 2-1, 2-). 3,2-4,2-8 ~ 2-1
See 3).

That is, the glass composition of the present invention exhibited a vivid color tone without disturbing the color development of the pigment, and was excellent in chemical resistance and peeling resistance. Therefore, the glass composition of the present invention can be used very suitably as a decorative material for ceramic products.

[0056]

The glass composition of the present invention is a sanitary and safe composition that does not contain lead at all, and does not interfere with the color development of the pigments mixed at the same time. Further, it is excellent in resistance to chemicals, the thermal expansion coefficient can be easily controlled, and the peeling resistance is also excellent. Therefore, it is preferably used as a decorative material for ceramic products, especially tableware. As a decorative material, the softening point is 700
Since it is a range adjusted to an appropriately low temperature side of ˜760 ° C., it can be widely applied to a glass frit of low-grade glaze and enamel, a flux of a painting material for in-glaze decoration and on-glaze decoration.

Since the above-mentioned lead-free glass composition is used as the flux component in the painting material of the present invention, it is safe from the viewpoint of hygiene and is excellent in the fusion property with the base material or the glazed surface, the peeling resistance and the chemical resistance. Moreover, it is possible to give a vivid decoration without hindering the color development of the pigment. Conventionally, it was difficult to obtain a vivid decoration especially for a blue type, but when decorated with the painting material of the present invention, the coloring of the blue type pigment appears without impairing, and a vivid decorative surface can be obtained. .

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Hirotsuki Hiroshi Aichi Prefecture Noritake Shinmachi 3-chome, Noritake Shinmachi, Nishi-ku, Nagoya-shi Noritake Company Limited (72) Inventor Kamiya Satoru Noritake Shincho 3-chome, Nishi-ku, Nagoya, Aichi Prefecture No. 1-36 Noritake Company Limited Limited

Claims (8)

[Claims] 1. SiO ₂ 45.0 to 60.0% by weight, Al ₂ O ₃ 4.0 to 18.0% by weight, alkali metal oxides in total 5.0 to 10.0% by weight (however, Li ₂ O 2.0 wt% or more) B ₂ O ₃ 15.0 to 30.0 wt% and ZrO ₂ 3.0 to 7.0 wt% Li ₂ O-Al ₂ O ₃ -SiO ₂ system It is a lead-free glass composition (total 100% by weight) and has a weight composition ratio of A
l ₂ O ₃ / Li ₂ O is 1.2 or more and the softening point is 700.
A lead-free glass composition, which is in the range of ˜760 ° C. 2. The glass composition according to claim 1, further comprising ZnO in an amount of more than 0% by weight and 14.0% by weight or less. 3. Further, 0 to 6.0% by weight of CaO, and / or
Or the glass composition of Claim 1 or 2 containing 0-4.0 weight% MgO. 4. The total weight of the lead-free glass composition,
An alkali metal oxide is composed of 2.0 to 5.0% by weight of Li ₂ O, 0 to 6.0% by weight of Na ₂ O, and 0 to 2.0% by weight of K ₂ O. Item 4. The glass composition according to any one of items 1 to 3. 5. The glass composition according to claim 1, which has a thermal expansion coefficient α of 92.0 × 10 ⁻⁷ or less. 6. The glass composition according to claim 5, wherein the thermal expansion coefficient α is 70.0 × 10 ⁻⁷ or less. 7. A lead-free painting material comprising the glass composition according to any one of claims 1 to 6 as a flux component. 8. The painting material according to claim 7, wherein a blue pigment is used as the pigment component.