JP3094375B2 - Natural marble-like crystallized glass and glass body for producing natural marble-like crystallized glass - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a crystallized glass,
In particular, the present invention relates to a natural marble-like crystallized glass used for interior and exterior materials of buildings.

[0002]

2. Description of the Related Art Crystallized glass having a natural marble pattern has excellent properties such as chemical durability and mechanical strength.
In addition, it is used for interior and exterior materials of buildings, instead of natural stone, because of its beautiful appearance.

Various types of crystallized glass of this type have been proposed in the past, for example, Japanese Patent Publication No. 51-2396.
No. 6 (U.S. Pat. No. 3,964,917) (hereinafter referred to as Conventional Example I) contains 50 to 65 wt% SiO ₂ and 3 to 13 wt% A.
l ₂ O ₃ , 15 to 25 wt% CaO, and 2 to 10 w
The crystalline glass composition having t% ZnO is heat treated to form β-wollastonite (Ca
It discloses a natural marble-like crystallized glass obtained by precipitating O.SiO ₂ ) crystals.

JP-B-53-39884 (hereinafter referred to as Conventional Example II) has a composition of 45 to 75 wt% SiO ₂ and 1 to 13 wt%.
Al ₂ O ₃ , 6 to 14.5 wt% CaO, but 1 to 1
_{3wt% Na 2 O + K 2} O, 0~20wt% BaO and 0~18wt% ZnO, but 4~24wt% BaO
Disclosed is a natural marble-like crystallized glass having + ZnO and having β-wollastonite crystals as main crystals.

[0005] Korean Patent Publication 91-9979 (hereinafter referred to as a conventional example)
III) is 55 to 63 wt% SiO ₂ ,
_wt% Al ₂ O 3, to precipitate 17~22wt% CaO, and then heat treating the crystallizable glass composition having 0.5~3wt% Li ₂ O and at least a portion of its surface layer β- wollastonite crystals Thus, a natural marble-like crystallized glass obtained thereby is disclosed.

JP-A-3-164446 (hereinafter referred to as Conventional Example IV) discloses 48-68 wt% SiO ₂ , 0.5-17 w
_{t% Al 2 O 3, 6~22wt} % CaO, 5~22wt
% R2O (R: Na, K) 0.2-8 wt% MgO, 0
６6 wt% B ₂ O ₃ , 0-8 wt% BaO, 0-9 wt
% ZnO, where BaO + ZnO is 15 wt% or less,
And 0 to 10% by weight of a colorant, and β
-Discloses natural marble-like crystallized glass with wollastonite crystals.

[0007]

When glass is heat-treated and crystallized on an industrial scale, large-scale firing furnaces such as shuttle kilns, tunnel kilns, and roller hearth kilns are usually used. The internal temperature distribution and the temperature rise / fall rate of the firing furnace are difficult to be uniform. For example, in the case of a tunnel kiln, a temperature difference of up to about ± 30 ° C. of the set temperature may occur in the furnace.

However, the known crystallized glasses disclosed in the above-mentioned Conventional Examples I and II have poor color tone stability under heat treatment conditions. It has the disadvantage that the color tone changes and the color tone becomes unstable, making it difficult to obtain a desired color tone. In particular, crystallized glass exhibiting a dark color tone such as gray or black has a remarkable tendency, and it is difficult to mass-produce with high yield using a large-scale firing furnace.

Further, the crystallized glass disclosed in Conventional Example III has a problem that it is easily devitrified and has poor melting properties, and therefore, it is difficult to mold a crystallized glass article. Further, there is a problem that a dark color cannot be obtained because of a large amount of crystals.

Further, the crystallized glass of Conventional Example IV has a problem that it is easily devitrified and the color tone stability is not good.

An object of the present invention is to provide a dark color tone because it satisfies various conditions required for exterior materials and interior materials, is resistant to devitrification, and has excellent color tone stability. It is also to provide a natural marble-like crystallized glass which can be produced in large quantities with a good yield, and a glass body used therefor.

[0012]

As a result of various studies, the present inventors have found that, in order to obtain excellent color tone stability, the crystallization speed is increased while suppressing the devitrification tendency of glass, and It was found that it was necessary to determine the glass composition so as to have an appropriate amount of crystals, and the present invention was proposed.

That is, the natural marble-like crystallized glass of the present invention contains 50 to 75% of SiO ₂ , 1 to 15% of Al ₂ O ₃ ,
_{aO6~16.5%, Li 2 O0.1~5%,} B 2 O 3
_{0~1.5%, CaO + Li 2 O} + B 2 O 3 10~1
7.5%, ZnO 2.5 to 12%, BaO 0 to 12%,
_{Na 2 O + K 2 O0.1~15%} , has a composition of colorant 0 to 10%, characterized by comprising precipitating β- wollastonite as a main crystal.

The present invention also relates to a method for preparing SiO _{2 by} weight percentage.
_{50~75%, Al 2 O 3 1~15} %, CaO6~1
_{6.5%, Li 2 O0.1~5%,} B 2 O 3 0~1.5
_{%, CaO + Li 2 O +} B 2 O 3 10~17.5%, Z
_{nO2.5~12%, BaO0~12%, Na 2} O + K
Having a composition of 0.1 to 15% ₂ O and 0 to 10% of a colorant,
An object of the present invention is to provide a glass body for producing a natural marble-like crystallized glass, which has a property of precipitating β-wollastonite as a main crystal.

[0015]

The reasons for limiting the composition range of the present invention are described below.

The content of SiO ₂ is 50-75%, preferably 57-70%. If the content of SiO ₂ is more than 75%, the melting temperature of the glass increases and the viscosity increases, resulting in poor fluidity during heat treatment. If it is less than 50%, the devitrification at the time of molding is increased, and the amount of β-wollastonite precipitated during the heat treatment is extremely reduced, so that the mechanical strength is reduced.

The content of Al ₂ O ₃ is 1 to 15%, preferably 3 to 10%. When the content of Al ₂ O ₃ is more than 15%, the melting property of the glass is deteriorated, and the color tone stability is deteriorated. When the content is less than 1%, the devitrification is increased, and the chemical durability is reduced.

CaO, Li ₂ O and B ₂ O ₃ are components deeply related to color tone stability. That is, in order to obtain excellent color tone stability, it is necessary to increase the crystallization rate while suppressing the devitrification tendency of glass as described above, and to have an appropriate amount of crystals. Is CaO, Li ₂
O is contained within a specific range, and the total amount of the three components obtained by adding B ₂ O ₃ to these components is 10 to 17.
It is important to limit to 5%.

CaO is a component that increases the crystallization rate and increases the amount of crystals to enhance the color tone stability. Its content is 6 to 16.5%, preferably 8 to 16%. If CaO is more than 16.5%, the devitrification will increase,
Molding becomes difficult. Further, the precipitation amount of β-wollastonite is too large, so that desired surface smoothness cannot be obtained, and at the same time, the coloring power by the colorant is reduced, so that it is difficult to obtain a dark color. On the other hand, if the content is less than 6%, the precipitation amount of β-wollastonite is reduced, so that the color tone stability is lowered and the material does not have a natural marble appearance. In addition, since the mechanical strength is reduced, it cannot be put to practical use as a building material.

Li ₂ O has the effect of increasing the crystallization rate, and its content is 0.1 to 5%, preferably 0.1 to 3%.
%. If the content of Li ₂ O is more than 5%, the chemical durability decreases. On the other hand, if it is less than 0.1%, the meltability and the fluidity are deteriorated, and the crystallization speed is lowered, so that the color tone stability is remarkably reduced.

B ₂ O ₃ is a component added to improve the meltability and fluidity of the glass and to increase the crystallization rate, and its content is 0 to 1.5%, preferably 0 to 1%.
%. When B ₂ O ₃ is used in a small amount, the effect of accelerating the crystallization speed can be obtained. However, when it is more than 1.5%, the crystallization speed is conversely lowered, and the color tone stability deteriorates.

In the present invention, CaO, Li ₂ O, B ₂
The total amount of O ₃ is 10 to 17.5%. The reasons for limiting the total amount of these three components in this way are as follows. That is, in the composition system of the present invention, each of these components functions to lower the viscosity of glass, so that the more these components, the more the tendency to devitrify. In particular, when the total amount is more than 17.5%, devitrification becomes remarkable and production becomes difficult, which is not preferable. Conversely, the less these components, the less the tendency to devitrify. However, if less than 10%, the viscosity of the glass becomes too high and the crystallization speed becomes slow, the amount of crystals becomes insufficient, and the color tone stability becomes remarkably high. Will drop.

The content of ZnO is 2.5 to 12%, preferably 2.9 to 9%. If ZnO is more than 12%, β
-Wollastonite hardly precipitates and does not have the appearance of natural marble, and sufficient mechanical strength cannot be obtained. On the other hand, if it is less than 2.5%, the fluidity is significantly reduced.

The content of BaO is 0 to 12%, preferably 0 to 7%. If the content of BaO is more than 12%, the precipitation amount of β-wollastonite will decrease, and the color stability and mechanical strength will decrease.

The total amount of Na ₂ O and K ₂ O is 0.1 to 15
%, Preferably 3 to 12%. If the total amount of these components is more than 15%, the chemical durability becomes poor, and 0.1%
If the amount is less, the viscosity increases and the meltability and fluidity deteriorate.

Fe ₂ O ₃ , NiO, Co
O, MnO ₂ , Cr ₂ O ₃ , CuO, etc. can be added up to 10%. However, if it exceeds this range, the fluidity will be extremely deteriorated at the time of heat treatment and the raw material cost will increase, which is not preferable.

In addition, the natural marble-like crystallized glass of the present invention contains up to 1% of a fining agent such as As ₂ O ₃ or Sb ₂ O ₃ in addition to the above-mentioned components.
O, and components of SrO, etc. up to 1.5%, respectively, TiO _2, Zr in the glass to stabilize and weaken the devitrification
Components such as O ₂ and P ₂ O ₅ may be contained up to 1% each. The amount of fining agents such as As ₂ O ₃ and Sb ₂ O ₃ is 1%
If it exceeds, it is environmentally unfavorable. MgO and SrO
If the content of each exceeds 1.5%, the crystal precipitation is adversely affected and the color stability is reduced. On the other hand, if the amount of TiO ₂ exceeds 1%, the cost becomes high and the color tone of the crystallized glass becomes yellowish. If the amount of ZrO ₂ exceeds 1%, the melting property of the glass decreases. If the amount of P ₂ O ₅ exceeds 1%, the phase of the glass tends to separate.

Next, a preferred method for producing the natural marble-like crystallized glass of the present invention will be described.

First, a glass raw material prepared so as to have the composition described above is melted and vitrified, and then a glass body is produced by a method such as water granulation. Next, when the glass particles are accumulated in a fire-resistant mold and heat-treated, the glass particles are fused and integrated, and a needle-like β-wollastonite is formed from the surface to the inside of each glass particle. Crystals precipitate,
The crystallization is completed. When the surface of the crystallized glass thus obtained is polished, crystallized glass exhibiting a natural marble pattern due to the shape of the glass body can be obtained.

It is to be noted that an inorganic pigment for ceramics such as rutile, spinel or zircon is added to the glass body and mixed in advance, and this mixture is accumulated in a mold, or two or more kinds of different color tones. Natural marble-like crystallized glass having various color patterns can be obtained by, for example, mixing glass small bodies or collecting glass bodies without mixing.

[0031]

EXAMPLES Hereinafter, the natural marble-like crystallized glass of the present invention will be described based on examples and comparative examples.

(Examples) Tables 1 to 4 show Examples (Samples Nos. 1 to 15) and Comparative Examples (Samples Nos. 16 to 19) of the present invention.

[0033]

[Table 1]

[0034]

[Table 2]

[0035]

[Table 3]

[0036]

[Table 4]

Each sample was prepared as follows.

The glass raw materials prepared to have the composition shown in the table in terms of weight percentage were prepared at a temperature of 1300 to 1500 ° C. for 5 to 5 hours.
Melted for 20 hours. This molten glass was put into water, water-granulated, dried and classified to obtain glass particles having a particle size of 1 to 5 mm. Next, the glass particles were accumulated in a fire-resistant mold having an inner wall coated with alumina powder as a release agent, placed in an electric furnace, and heat-treated for 2 hours (optimum heat treatment) under the optimum heat treatment conditions shown in the table. By holding at a temperature for 2 hours), each glass body was fused and integrated and crystallized to obtain a sample.

For each sample thus obtained,
Sample No. Sample Nos. 1 to 10 are white. 11 and 12
Is beige, sample No. Samples Nos. 13, 14, 16 to 18 are gray. 15 had a black color. But,
Sample No. In No. 19, evaluation after crystallization was not performed because devitrified matters were observed at the stage of molding into glass bodies.

No. When the precipitated crystals of each of Samples 1 to 18 were qualitatively analyzed by X-ray diffraction, β-wollastonite was precipitated as a main crystal in all the samples.

When the surface of each sample was polished, a beautiful natural marble pattern appeared with a small amount of polishing.

Next, each of the obtained samples was evaluated for acid resistance, alkali resistance, bending strength, and color stability, and the values are shown in Tables 1 to 4.

The flexural strength was measured by a four-point load method using a sample of 50 × 250 × 17 mm, and the acid resistance and alkali resistance were each measured at 90 ° C., 1% H ₂ SO ₄ and NaOH in an aqueous solution at 25 ° C. A 25 × 5 mm sample (mirror polished product) was evaluated by weight loss after immersion for 24 hours. Further, the color tone stability was twice the optimal temperature rise / fall rate shown in the table (that is, 12 times).
(0 ° C./hour), a sample was prepared by heat treatment at a temperature 20 ° C. lower than the optimum heat treatment temperature, and the color difference (ΔE) from the sample heat-treated under the optimum heat treatment condition was measured using a color difference meter. During the heat treatment, each sample was kept at the heat treatment temperature shown in Tables 1 to 2 for 2 hours.

For comparison, the properties of natural marble were measured and found to be 34.0 mg / acid.
cm ² , alkali resistance was 3.0 mg / cm ² , and flexural strength was 170 kgf / cm ² .

As is clear from the table, the sample No. 1 to 15 have an acid resistance of 0.04 to 0.1
3 mg / cm ² , alkali resistance 0.40 to 0.48 m
g / cm ² , bending strength of 400 to 500 kgf / cm ²
And all properties were superior to natural marble. Further, regarding the color tone stability, the color difference is 0.2 to 1.
It was 2.

Sample No. as a comparative example As is clear from the table, 16 to 18 have an acid resistance of 0.08 to 0.11 mg.
/ Cm ² , alkali resistance 0.40 to 0.48 mg / c
m ² , and the flexural strength were 400 to 460 kgf / cm ² , showing values equivalent to those of the examples. However, the sample N having a color difference of 2.5 to 3.7 and exhibiting the same gray color
o. The color difference is 1.8 to 2.1 as compared with 13 and 14.
Was also big.

Next, an experiment was conducted to evaluate the effect of the presence or absence of Li ₂ O and the heat treatment conditions on the color.

[0048]

[Table 5]

Sample No. 1 according to the present invention having the composition shown in Table 5 11 and Sample No. 11 as a comparative example. Samples Nos. 20 and 21 were prepared by the same manufacturing method as described above, except that the heat treatment conditions were changed as shown in Table 5. Each sample had a beige color. The color difference was determined for each of the samples having different heat treatment conditions in the same manner as above. Table 5 shows the results.
Shown in

From Table 5, it can be seen that the sample No. of the comparative example containing no Li ₂ O. In Nos. 20 and 21, the color difference changes in the range of 2.0 to 4.0 and 2.0 to 4.3 due to the change in the heat treatment conditions. On the other hand, the sample N of the embodiment of the present invention
o. In No. 11, the value is in the range of 0.9 to 1.2, and the change in the color tone due to the change in the heat treatment condition is small, and thus it is clear that the color tone stability is excellent.

[0051]

The natural marble-like crystallized glass of the present invention is
Since it has high chemical durability and mechanical strength and exhibits a beautiful natural marble pattern, it is suitable as an interior or exterior material for buildings. Moreover, because it has excellent color tone stability,
Even a crystallized glass exhibiting a dark color tone can be mass-produced with high yield.

────────────────────────────────────────────────── ─── Continuation of the front page (56) References JP-A-3-146439 (JP, A) JP-A-63-201037 (JP, A) JP-A-3-164446 (JP, A) (58) Survey Field (Int.Cl. ⁷ , DB name) C03C 1/00-14/00 C04B 35/16 C03B 32/02 C03B 19/06

Claims (10)

(57) [Claims] (1) 50 to 75% by weight of SiO ₂ ,
Al ₂ O ₃ 1 to 15%, CaO 6 to 16.5%, Li _{2
O0.1~5%, B 2 O 3 0~1.5} %, CaO + Li
₂ O + B ₂ O ₃ 10-17.5%, ZnO 2.5-12
_{%, BaO0~12%, Na 2 O} + K 2 O0.1~15
% And a colorant of 0 to 10%, and β-
A natural marble-like crystallized glass obtained by precipitating wollastonite. 2. The natural marble-like crystallized glass according to claim 1, wherein the coloring agent is Fe ₂ O ₃ , NiO, CoO,
A natural marble-like crystallized glass characterized by being at least one of MnO ₂ , Cr ₂ O ₃ , and CuO. 3. The natural marble-like crystallized glass according to claim 1, wherein at least one of As ₂ O ₃ and Sb ₂ O ₃ is contained as a fining agent in an amount of 1% or less. Glass. 4. The natural marble-like crystallized glass according to claim 1, wherein at least one of 1.5% or less of MgO and 1.5% or less of SrO is used to improve the melting property of the glass.
A natural marble-like crystallized glass comprising: 5. The natural marble-like crystallized glass of claim 1, wherein T is used to stabilize the glass and reduce the devitrification.
A natural marble-like crystallized glass containing at least 1% of each of iO ₂ , ZrO ₂ , and P ₂ O ₅ . 6. SiO ₂ 50-75% by weight,
Al ₂ O ₃ 1 to 15%, CaO 6 to 16.5%, Li _{2
O0.1~5%, B 2 O 3 0~1.5} %, CaO + Li
₂ O + B ₂ O ₃ 10-17.5%, ZnO 2.5-12
_{%, BaO0~12%, Na 2 O} + K 2 O0.1~15
% And a colorant of 0 to 10%, and β-
A glass body for producing a natural marble-like crystallized glass, having a property of precipitating wollastonite. 7. The glass body for producing a natural marble-like crystallized glass according to claim 6, wherein the coloring agent is Fe ₂ O ₃ ,
A glass body for producing a natural marble-like crystallized glass, wherein the glass body is at least one of NiO, CoO, MnO ₂ , Cr ₂ O ₃ , and CuO. 8. The glass body for producing a natural marble-like crystallized glass according to claim 6, wherein at least one of As ₂ O ₃ and Sb ₂ O ₃ is contained as a fining agent in an amount of 1% or less. Glass body for producing natural marble-like crystallized glass. 9. The glass body for producing a natural marble-like crystallized glass according to claim 6, wherein 1.5% or less of MgO and 1.5% or less of Sr are used for improving the melting property of the glass.
A glass body for producing a natural marble-like crystallized glass, comprising at least one of O. 10. The glass body for producing a natural marble-like crystallized glass according to claim 6, wherein at least one of TiO ₂ , ZrO ₂ , and P ₂ O ₅ is used for stabilizing the glass and weakening the devitrification. A glass body for producing a natural marble-like crystallized glass, characterized in that the glass body contains up to 1% of each.