Low-expansion borosilicate transparent glaze and a preparation method and use thereof

Abstract

Disclosed is a low-expansion borosilicate transparent glaze, a preparation method thereof, and use thereof in preparation of a glaze product by secondary fusion-cast molding. The low-expansion borosilicate transparent glaze has raw material composition by mass percentage including: 72%-80% of SiO.sub.2, 4%-12% of B.sub.2O.sub.3, 4%-12% of Na.sub.2O, 0.1%-4% of CaO, 0.1%-6% of Al.sub.2O.sub.3, 0-0.05% of Fe.sub.2O.sub.3, 0-2% of MgO, 0-2% of K.sub.2O, 0-2% of ZnO, 0-2% of BaO, 0-2% of ZrO.sub.2, 0-0.5% of Li.sub.2O, and 0-0.5% of TiO.sub.2, wherein a sum of mass percentages of SiO.sub.2, B.sub.2O.sub.3 and Al.sub.2O.sub.3 is 85%-95%. The preparation method includes steps of: (1) after mixing dried raw materials, melting at 1400-1540 C. to obtain a high-temperature glass melt; (2) cooling the high-temperature glass melt to 1150-1230 C. to mold; and (3) annealing a molded glass at 530-600 C. to obtain the low-expansion borosilicate transparent glaze.

Claims

1. A preparation method of a glaze product, characterized in comprising the following steps: putting a low-expansion borosilicate transparent glaze within a mould to undergo secondary fusion-cast molding at 1100-1200 C., and then annealing to obtain the glaze product; maintaining the secondary fusion-cast molding temperature at 1100-1200 C. for 25-35 minutes, then, within 60 minutes thereafter, lowering temperature to an annealing temperature of 590-610 C., and maintaining the annealing temperature for 15-25 minutes, then lowering temperature to 490-510 C. at a rate of 1-2 C./minute, and finally lowering temperature to 35-45 C. at a rate of 3-5 C./minutes to obtain the glaze product; wherein the glaze product has a surface and a texture without any trace of split-joint; wherein the low-expansion borosilicate transparent glaze's raw materials composition by mass percentage comprises: SiO.sub.2 72%-80%, B.sub.2O.sub.3 4%-12%, Na.sub.2O 4%-12%, CaO 0.1%-4%, Al.sub.2O.sub.3 0.1%-6%, Fe.sub.2O.sub.3 0-0.05%, MgO 0-2%, K.sub.2O 0-2%, ZnO 0-2%, BaO 0-2%, ZrO.sub.2 0-2%, Li.sub.2O 0-0.5%, and TiO.sub.2 00.5%; wherein a sum of mass percentages of SiO.sub.2, B.sub.2O.sub.3 and Al.sub.2O.sub.3 is 85%-95%; and wherein the low-expansion borosilicate transparent glaze has an average linear thermal expansion coefficient of (50-60)10.sup.6/ C. within a range of 20-300 C.

2. The method according to claim 1, wherein the low-expansion borosilicate transparent glaze further comprises ZnO with a mass percent content ranging from 0.5-1%.

3. The method according to claim 1, wherein the low-expansion borosilicate transparent glaze is prepared by the following steps: (1) after mixing dried raw materials, melting the dried raw materials at 1400-1540 C. to obtain a high-temperature glass melt; (2) cooling the high-temperature glass melt to 1150-1230 C. to mold; and (3) annealing the molded glass at 530-600 C. to obtain the low-expansion borosilicate transparent glaze.

4. The preparation method according to claim 3, characterized in that in step (1), time for the melting is 10-25 hours.

5. A glaze product prepared by the preparation method according to claim 1.

Description

DESCRIPTION OF DRAWINGS

(1) FIG. 1 is a physical photograph of the low-expansion borosilicate transparent glaze of Example 1;

(2) FIG. 2 is a physical photograph of the glaze product of Example 1;

(3) FIG. 3 is a temperature graph of a preparation process of the glaze product of Example 1;

(4) FIG. 4 is a physical photograph of the glaze product of Comparison Example 1;

(5) FIG. 5 is a physical photograph of the glaze product of Comparison Example 2; and

(6) FIG. 6 is a physical photograph of the glaze product of Example 3.

DETAILED DESCRIPTION OF EMBODIMENTS

(7) The present invention will be further explained below in combination with figures and specific examples. It should be understood that these examples are only intended to describe the present invention instead of limiting the scope of the present invention. In the following examples, an operation method without indicating specific conditions is usually according to normal conditions or conditions recommended by manufacturers.

(8) Testing Standards:

(9) Elastic modulus: JC/T678678-1997 Test method for elastic modulus, shear modulus and Poisson ratio of glass material; Linear thermal expansion coefficient: JC/T679-1997 Test method for average linear thermal expansion coefficient of glass; and Chemical stability: GB/T 6584-1997 Particle test method and grading of water tolerance of glass at 98 C.

Example 1

(10) The raw material composition by mass percentage of the low-expansion borosilicate transparent glaze of the present example is: SiO.sub.2: 76.1%, B.sub.2O.sub.3: 9%, Na.sub.2O: 9%, CaO: 0.1%, Al.sub.2O.sub.3: 3.3%, ZnO: 0.5%, ZrO.sub.2: 1.97%, Fe.sub.2O.sub.3: 0.03%.

(11) The preparation method was performed by the following steps: (1) after mixing dried raw materials in proportion, melting at 1520 C. for 10 hours to obtain a high-temperature glass melt; (2) cooling the high-temperature glass melt to 1150 C. to mold; (3) annealing the molded glass at 595 C.; (4) cutting; (5) testing; (6) packing; and (7) entering into storage to obtain the low-expansion borosilicate transparent glaze.

(12) The above-mentioned low-expansion borosilicate transparent glaze as shown in FIG. 1 has an elastic modulus of 75 GPa, a linear thermal expansion coefficient (20-300 C.) of 5310.sup.6/ C., and chemical stability of Grade 1.

(13) The above-mentioned low-expansion borosilicate transparent glaze was used to prepare a glaze product by: putting the low-expansion borosilicate transparent glaze material lumps within a high-temperature mould, putting into a high-temperature furnace to raise the temperature to 1200 C. at 10 C./minute, holding for 30 minutes, then rapidly transferring into an annealing furnace, keeping the glass and mould within the furnace for 60 minutes to lower the temperature to an annealing temperature 600 C., and holding at this temperature for 20 minutes, then in 70 minutes lowering the temperature to 500 C., and finally in 100 minutes cooling to 40 C., with the temperature curve shown in FIG. 3.

(14) As shown in FIG. 2, the obtained glaze product has a smooth and limpid surface and an even internal texture without any trace of split-joint.

Example 2

(15) The raw material composition by mass percentage of the low-expansion borosilicate transparent glaze of the present example is:

(16) SiO.sub.2: 75.1%, B.sub.2O.sub.3: 10%, Na.sub.2O: 6.7%, CaO: 1.0%, BaO: 1.93%, Al.sub.2O.sub.3: 3.5%, K.sub.2O: 1.0%, ZnO: 0.64%, Li.sub.2O: 0.1%, Fe.sub.2O.sub.3: 0.03%.

(17) The preparation method was performed by the following steps: (1) after mixing dried raw materials in proportion, melting at 1530 C. for 10 hours to obtain a high-temperature glass melt; (2) cooling the high-temperature glass melt to 1200 C. to mold; (3) annealing the molded glass at 593 C.; (4) cutting; (5) testing; (6) packing; and (7) entering into storage to obtain the low-expansion borosilicate transparent glaze.

(18) The above-mentioned low-expansion borosilicate transparent glaze has an elastic modulus of 74 GPa, a linear thermal expansion coefficient (20-300 C.) of 5510.sup.6/ C., and chemical stability of Grade 1.

(19) The above-mentioned low-expansion borosilicate transparent glaze was used to prepare a glaze product by: putting the low-expansion borosilicate transparent glaze material lumps within a high-temperature mould, putting into a high-temperature furnace to raise the temperature to 1180 C. at 10 C./minute, holding for 30 minutes, then rapidly transferring into an annealing furnace, keeping the glass and mould within the furnace for 30 minutes to lower the temperature to an annealing temperature 600 C., and holding at this temperature for 20 minutes, then lowering the temperature to 500 C. at 1.5 C./minute, and finally cooling to 40 C. at 4 C./minute.

(20) The obtained glaze product has a smooth and limpid surface and an even internal texture without any trace of split-joint.

(21) Table 1 below shows the raw material composition of the borosilicate transparent glaze of Comparison Example 1, Comparison Example 2, Example 3.

(22) TABLE-US-00001 TABLE 1 Ingredients Comparison Comparison (w.t. %) Example 1 Example 2 EXAMPLE 3 B.sub.2O.sub.3 11 9.14 9.10 SiO.sub.2 68.3 72.77 77.30 Al.sub.2O.sub.3 2.5 1.95 3.39 Na.sub.2O 8.6 6.67 5.00 K.sub.2O 1.45 1.26 0.65 CaO 3 3.04 0.20 MgO 1.9 1.9 1.09 Li.sub.2O 0.15 0.17 0.17 TiO.sub.2 0.1 0.1 0.1 ZnO 1 1 1 BaO 2 2 2

(23) The preparation methods of the borosilicate transparent glaze of Comparison Example 1, Comparison Example 2, Example 3 were performed by the following steps: (1) after mixing dried raw materials in proportion, melting at 1530 C. for 12 hours to obtain a high-temperature glass melt; (2) cooling the high-temperature glass melt to 1210 C. to mold; (3) annealing the molded glass at 593 C.; (4) cutting; (5) testing; (6) packing; and (7) entering into storage to obtain the low-expansion borosilicate transparent glaze.

(24) The borosilicate transparent glaze of Comparison Example 1, Comparison Example 2, Example 3 has an elastic modulus of 75, 74, 76 GPa respectively, a linear thermal expansion coefficient (20-300 C.) of 5310.sup.6/ C., 5410.sup.6/ C., 5210.sup.6/ C. respectively, and chemical stability of Grade 1 for all.

(25) The above-mentioned borosilicate transparent glaze of Comparison Example 1, Comparison Example 2, Example 3 was used respectively to prepare a glaze product by: putting the borosilicate transparent glaze material lumps within a high-temperature mould, putting into a high-temperature furnace to raise the temperature to 1180 C. at 10 C./minute, holding for 30 minutes, then rapidly transferring into an annealing furnace, keeping the glass and mould within the furnace for 30 minutes to lower the temperature to an annealing temperature 600 C., and holding at this temperature for 20 minutes, then lowering the temperature to 500 C. at 1.5 C./minute, and finally cooling to 40 C. at 4 C./minute, thus to obtain the glaze products as shown in FIG. 4, FIG. 5, FIG. 6 respectively.

(26) It was clear that the glaze products prepared from the borosilicate transparent glaze of Comparison Example 1, Comparison Example 2 showed white scale-shaped substances on surface, and apparent internal split-joint traces. The glaze product prepared from the borosilicate transparent glaze of Example 3 has a smooth and limpid surface and an even internal texture without any trace of split-joint.

(27) Furthermore, it should be understood that after reading the contents of the present invention as described above, those of skill in the art can make various changes and modifications to the present invention, and such equivalents are also deemed to be within the scope of the present application as defined by the appended claims.