Rotating tube for low-foaming medicinal glass molding and preparation method thereof

Abstract

The invention discloses a rotary tube for low-foaming pharmaceutical glass molding and a preparation method thereof, and relates to the technical field of rotary tubes. The technical scheme is as follows: comprising the following components in mass percentage: 50-65% corundum particles; 15-25% corundum fine powder; 10-25% composite phosphate fine powder; 3-5% sintering agent; 2-5% binder; wherein the composite phosphate fine powder is a mixture of zirconium phosphate fine powder and aluminum phosphate fine powder, and the mass ratio of zirconium phosphate fine powder to aluminum phosphate fine powder is (1-3): (1-3). The rotary tube product for pharmaceutical glass molding produced by the present invention has good thermal shock resistance, high glass erosion resistance, and low foaming, which is beneficial to prolonging the service life of the rotary tube for pharmaceutical glass molding and improving the yield rate of the rotary tube for pharmaceutical glass molding.

Description

Technical Field

[0001] The invention relates to the technical field of rotary tubes, in particular to a rotary tube for molding low-foaming medicinal glass and a preparation method thereof. Background Art

[0002] Medium borosilicate pharmaceutical glass is widely used in the medical field, mainly for the manufacture of medical devices such as medicine bottles, syringes and test tubes. Pharmaceutical glass has excellent biocompatibility and chemical stability, and can store and transport drugs without changing the chemical composition of the drugs, ensuring the quality and safety of the drugs.

[0003] The borosilicate pharmaceutical glass rotary tube is the most critical component of the glass tube drawing system. The quality of its material and the stability of its use directly affect the quality and cost of pharmaceutical glass production. During the melting and forming process, the rotary tube has problems such as too high melting temperature, high viscosity at high temperature, difficulty in clarification, and serious corrosion of the rotary tube material. During the production process, such rotary tube materials should have good corrosion resistance, so that the glass liquid will not be contaminated by stripes, stones, bubbles, etc. due to the dissolution of corrosive substances during the drawing of the rotary tube. At the same time, the material must also ensure good thermal shock resistance.

[0004] Chinese invention patent CN116161862A discloses a rotary tube for special glass preparation and its preparation method, including the following raw materials: 40-70% ZrO2, 5-10% α-Al2O3, 2-5% Al2O3, 2-4% SiO2, 15-40% mullite crystal, 3-5% Y2O3, 2-4% MgO; the raw materials are blanked, shaped, dried, and sintered at 1550-1600℃ for 16-20h to obtain the product. The product prepared by this patent, on the one hand, contains a large amount of unstable and high thermal expansion ZrO2 components, on the other hand, ZrO2 will undergo phase change during use, making it very easy to explode and crack during installation and use, reducing the service life of the rotary tube. At the same time, the presence of a large amount of mullite phase will produce nepheline after contact with special medicinal glass liquid, and the glass liquid will produce bubbles, affecting the quality of the glass tube.

[0005] Chinese invention patent CN110282989A discloses a rotary tube and its preparation method. The raw materials are as follows: 30-50% of waste fused zirconium corundum bricks, 20-30% of mullite, 5-10% of sillimanite, 5-10% of kaolin, 1-20% of nano-alumina, 0.3-5% of sintering agent, and the waste fused zirconium corundum raw materials are aggregate materials, and the particle size ratio is: 40-80% of 0.045-1mm, 20-60% of 1-2mm. Through isostatic pressing and sintering at high temperature of 1480-1520℃, the porosity of the obtained product is less than 0.4%. This patent solves the problems of low volume density and high porosity of the rotary tube, but from the analysis of this technical field, too dense products will seriously affect the thermal stability of the product and reduce its service life; on the other hand, too much sillimanite and mullite components in the product will react with glass to produce nepheline, resulting in poor corrosion resistance of the product and bubbles in the glass liquid.

[0006] Chinese invention patent CN114988894A discloses a lightweight thermal shock resistant mullite cordierite rotating tube and its preparation method, the raw materials include 50-70wt.% high-purity sintered mullite, 8-20wt.% talc, 7-15wt.% alumina powder, 4-10wt.% silica powder and 3-25wt.% binding clay. The main chemical components of talc are: MgO: 31-36wt.%, SiO2: 44-48wt.%, and the particle size is ≤0.044mm. After the raw materials are mixed in a stirring pot, they are isostatically pressed and fired at 1350-1420℃ to obtain the product. The thermal expansion coefficient (20-1000℃) of the obtained product is 3.5-5.0×10 -6 / K, thermal shock test (1100℃ water cooling) after 20 cycles without cracking, high thermal shock stability, suitable for glass kiln rotary tube material. However, mullite and cordierite phases react violently with pharmaceutical glass, and the rotary tube material is easily corroded.

[0007] Chinese invention patent CN115448709A discloses an anti-corrosion rotary tube for glass kiln tube drawing machine and its preparation method. The raw materials include 20-50% sintered mullite, 15-30% fused mullite, 5-25% fused zirconium mullite, 5-25% zircon, 5-15% alumina powder, 8-15% bonding clay. The raw materials are mixed, isostatically pressed, and fired at 1550-1580℃ for 6-10h. The obtained rotary tube product has high thermal shock resistance, excellent corrosion resistance, and does not pollute the glass liquid. However, among its components, the matrix part contains a large amount of silicate mineral phases, such as mullite, zircon, clay and other components. When in contact with special medicinal glass, it will decompose, silicon dioxide will dissolve, and stones and bubbles will appear in the glass liquid.

[0008] Therefore, it is urgently necessary to develop new rotary tube materials with low foaming, good corrosion resistance and good thermal shock resistance as medium-borosilicate pharmaceutical glass, so as to extend the service life of rotary tubes used for molding medium-borosilicate pharmaceutical glass and improve its manufacturing qualification rate. Summary of the invention

[0009] The technical problem to be solved by the present invention is: to overcome the shortcomings of the prior art, to provide a low-foaming rotary tube for pharmaceutical glass molding and a preparation method thereof, and the manufactured pharmaceutical glass molding rotary tube product has good thermal shock resistance, high glass erosion resistance, and low foaming, which is beneficial to extending the service life of the pharmaceutical glass molding rotary tube and improving the yield of the pharmaceutical glass molding rotary tube.

[0010] The technical solution of the present invention is:

[0011] In one aspect, the present invention provides a rotary tube for low-foaming pharmaceutical glass molding, comprising the following components in percentage by mass, wherein the total mass of the remaining components except the binder is 100%, and the binder is calculated as a percentage of the total mass of the remaining components:

[0012] Corundum particles 50-65%;

[0013] Corundum fine powder 15-25%;

[0014] Compound phosphate fine powder 10-25%;

[0015] Sintering agent 3-5%;

[0016] Binder 2-5%;

[0017] The composite phosphate fine powder is a mixture of zirconium phosphate fine powder and aluminum phosphate fine powder, and the mass ratio of the zirconium phosphate fine powder to the aluminum phosphate fine powder is (1-3): (1-3).

[0018] Preferably, among the corundum particles, the mass of the corundum particles with a particle size of 0.5-1 mm accounts for 20-30% of the total mass of the remaining components except the binder, and the mass of the corundum particles with a particle size of 0.1-0.5 mm accounts for 25-35% of the total mass of the remaining components except the binder.

[0019] Preferably, the particle size of the corundum fine powder is ≤0.088 mm.

[0020] Preferably, the sintering promoting agent is clay.

[0021] Preferably, the clay particle size is ≤45 μm.

[0022] Preferably, the binder is a calcium lignin sulfonate solution or a magnesium lignin sulfonate solution.

[0023] Preferably, the concentration of the calcium lignin sulfonate solution or the magnesium lignin sulfonate solution is 50 wt.%.

[0024] On the other hand, the present invention provides a method for preparing the above-mentioned low-foaming pharmaceutical glass molding rotary tube, comprising the following steps:

[0025] S1: Pour the corundum particles, composite phosphate fine powder and sintering agent into a strong mixer, dry mix for 2-3 minutes, then add the binder and mix for 3-5 minutes;

[0026] S2 Add corundum fine powder and mix for 3-5 minutes to obtain mud;

[0027] S3 uses a 2mm sieve to remove mud agglomerates;

[0028] S4 The sieved clay is poured into a mold and isostatically pressed into a green body with a fixed shape and size;

[0029] S5: drying the green body;

[0030] S6 The dried green body is loaded into a kiln for sintering;

[0031] S7 processes the sintered green body into a rotating tube for forming low-foaming pharmaceutical glass.

[0032] Preferably, in step S4, the isostatic pressing pressure is 100 MPa and the time is 1 min.

[0033] Preferably, in step S5, the drying temperature is 110-180° C., and the drying time is 6-24 hours.

[0034] Preferably, in step S6, the sintering temperature is 1400-1550° C., and the sintering time is 5-24 hours.

[0035] Compared with the prior art, the present invention has the following beneficial effects:

[0036] 1. The present invention introduces composite phosphate fine powder as a binding phase in the rotary tube for pharmaceutical glass molding. Compared with the prior art, the erosion rate of the prepared rotary tube for pharmaceutical glass molding at 1300°C is reduced to less than 0.1mm / 24h. When preparing the rotary tube for pharmaceutical glass molding, the present invention uses composite phosphate fine powder to reduce the sintering difficulty of pure corundum material. After the corundum fine powder and the composite phosphate fine powder are sintered, a binding phase of a multi-phase combination of aluminum phosphate, zirconium phosphate and corundum is formed, which improves the thermal shock resistance of the product; and the multi-phase combination of aluminum phosphate, zirconium phosphate, corundum and other binding phases of a specific composition make the prepared rotary tube for pharmaceutical glass molding have low foaming properties, which can effectively reduce the bubbles formed during the molding process of the rotary tube for pharmaceutical glass molding.

[0037] 2. In the pharmaceutical glass forming rotary tube prepared by the present invention, the content of aluminum oxide is greater than 78%, the content of phosphorus oxide is greater than 9%, and the content of aluminum oxide and phosphorus oxide is greater than 89%, the apparent porosity is less than 17%, and the bulk density is greater than 3.04 g / cm 3 , compressive strength ≥138MPa, 1100℃ water-cooled thermal shock test ≥16 times; 1300℃×48h dynamic erosion rate ≤0.1mm / 24h, 1300℃×48h foaming index ≤2. DETAILED DESCRIPTION

[0038] In order to enable persons skilled in the art to better understand the technical solution of the present invention, the technical solution of the present invention will be clearly and completely described below in conjunction with the embodiments of the present invention.

[0039] Example 1

[0040] The formula of the low-foaming pharmaceutical glass molding rotary tube of this embodiment is shown in Table 1, and its preparation method comprises the following steps:

[0041] S1: Pour the corundum particles, composite phosphate fine powder and sintering agent into a strong mixer, dry mix for 3 minutes, and then add the binder and mix for 3 minutes;

[0042] S2 adds corundum fine powder and kneads for 5 minutes to obtain mud;

[0043] S3 uses a 2mm sieve to remove mud agglomerates;

[0044] S4 The sieved clay is poured into a mold and isostatically pressed into a green body with a fixed shape and size;

[0045] S5: drying the green body at 110°C for 24h;

[0046] S6 The dried green body is loaded into the kiln, heated to 1450℃, and kept at this temperature for 12h for sintering;

[0047] The sintered green body of S7 is processed into a rotating tube for low-foaming pharmaceutical glass molding.

[0048] Example 2

[0049] The formula of the low-foaming pharmaceutical glass molding rotary tube of this embodiment is shown in Table 1, and its preparation method comprises the following steps:

[0050] S1: Pour the corundum particles, composite phosphate fine powder and sintering agent into a strong mixer, dry mix for 2 minutes, and then add the binder and mix for 4 minutes;

[0051] S2 adds corundum fine powder and kneads for 3 minutes to obtain mud;

[0052] S3 uses a 2mm sieve to remove mud agglomerates;

[0053] S4 The sieved clay is poured into a mold and isostatically pressed into a green body with a fixed shape and size;

[0054] S5: drying the green body at 180°C for 6h;

[0055] S6 The dried green body is loaded into the kiln, heated to 1550℃, and kept at this temperature for 5h for sintering;

[0056] The sintered green body of S7 is processed into a rotating tube for low-foaming pharmaceutical glass molding.

[0057] Example 3

[0058] The formula of the low-foaming pharmaceutical glass molding rotary tube of this embodiment is shown in Table 1, and its preparation method comprises the following steps:

[0059] S1: Pour the corundum particles, composite phosphate fine powder and sintering agent into a strong mixer, dry mix for 3 minutes, and then add the binder and mix for 5 minutes;

[0060] S2 added corundum fine powder and kneaded for 4 minutes to obtain mud;

[0061] S3 uses a 2mm sieve to remove mud agglomerates;

[0062] S4 The sieved clay is poured into a mold and isostatically pressed into a green body with a fixed shape and size;

[0063] S5: drying the green body at 150°C for 12h;

[0064] S6 The dried green body is loaded into the kiln, heated to 1400℃, and kept at this temperature for 24h for sintering;

[0065] The sintered green body of S7 is processed into a rotating tube for low-foaming pharmaceutical glass molding.

[0066] Example 4

[0067] The formula of the low-foaming pharmaceutical glass molding rotary tube of this embodiment is shown in Table 1, and its preparation method comprises the following steps:

[0068] S1: Pour the corundum particles, composite phosphate fine powder and sintering agent into a strong mixer, dry mix for 3 minutes, and then add the binder and mix for 5 minutes;

[0069] S2 added corundum fine powder and kneaded for 4 minutes to obtain mud;

[0070] S3 uses a 2mm sieve to remove mud agglomerates;

[0071] S4 The sieved clay is poured into a mold and isostatically pressed into a green body with a fixed shape and size;

[0072] S5: drying the green body at 110°C for 12h;

[0073] S6 The dried green body is loaded into the kiln, heated to 1400℃, and kept at this temperature for 24h for sintering;

[0074] The sintered green body of S7 is processed into a rotating tube for low-foaming pharmaceutical glass molding.

[0075] Table 1 Formula of the low foaming pharmaceutical glass forming rotary tube of Examples 1-4

[0076]

[0077] In Table 1, the total mass of the remaining components except the binder is calculated as 100%, and the binder is calculated as the percentage of the total mass of the remaining components.

[0078] Comparative Examples 1-6

[0079] The formulas of the rotary tubes for pharmaceutical glass molding of Comparative Examples 1-6 are shown in Table 2, and the preparation methods are the same as those of Example 1.

[0080] Table 2 Formula of the rotating tube for pharmaceutical glass molding of Comparative Examples 1-6

[0081]

[0082] The performance tests of the pharmaceutical glass forming rotary tubes prepared in Examples 1-4 and Comparative Examples 1-6 are shown in Tables 3-4. The apparent porosity and bulk density are tested in accordance with GB / T2997-2015 Test Method for Bulk Density, Apparent Porosity and True Porosity of Dense Shaped Refractory Products, the compressive strength is tested in accordance with GB / T5072-2023 Test Method for Compressive Strength of Refractory Materials at Room Temperature, the thermal shock resistance is tested in accordance with YB / T376.1-1995 Test Method for Thermal Shock Resistance of Refractory Products (Water Rapid Cooling Method), the dynamic erosion rate is tested in accordance with Zheng Chong. Test Equipment and Test Method for Dynamic Erosion of Refractory Materials Against Liquid Glass [J]. Glass, 2023, 50 (12): 21-25, and the foaming index is tested in accordance with JC / T639-1996 Test Method for Bubble Separation Rate of Refractory Materials for Glass Melting Furnaces.

[0083] Table 3 Performance test results of the rotary tube for pharmaceutical glass molding prepared in Examples 1-4

[0084]

[0085] Table 4 Performance test results of the rotary tube for pharmaceutical glass molding prepared in Comparative Examples 1-6

[0086]

[0087] It can be seen from Table 3 that the apparent porosity of the pharmaceutical glass forming rotary tubes prepared in Examples 1-4 of the present invention is less than 17% and the bulk density is greater than 3.04 g / cm 3 , compressive strength ≥ 138MPa, 1100℃ water-cooled thermal shock test ≥ 16 times; 1300℃×48h dynamic erosion rate ≤ 0.1mm / 24h, 1300℃×48h foaming index ≤ 2; aluminum oxide content > 78%, phosphorus oxide content > 9%, and the total mass of aluminum oxide and phosphorus oxide > 89%. It can be seen that the rotary tube products for pharmaceutical glass molding prepared in Examples 1-4 of the present invention have excellent properties of good thermal shock resistance, high erosion resistance and low foaming.

[0088] As can be seen from Table 4, the thermal shock resistance of the corundum-mullite composite pharmaceutical glass molding rotary tube prepared in Comparative Example 1 is significantly reduced to 10 times, and the dynamic erosion rate at 1300°C is increased to 0.46 mm / 24h, and the foaming index is increased to 5. This is because the mullite raw material present in large quantities in the system reacts with alkali metals, boron oxide and other substances in the glass, resulting in the decomposition of the mullite fine powder, generating a liquid phase of corundum and nepheline, from which the corundum is desolvated, and the reaction site will produce an expansion effect, thereby reducing the product's resistance to glass erosion, and bubbles will be generated around it.

[0089] In the composite phosphate fine powder of Comparative Example 2, the amount of aluminum phosphate fine powder added is too little, while the amount of zirconium phosphate fine powder added is too much. In the composite phosphate fine powder of Comparative Example 3, the amount of aluminum phosphate fine powder and zirconium phosphate fine powder added are both too little. In the composite phosphate fine powder of Comparative Example 4, the amount of aluminum phosphate fine powder added is too much, while the amount of zirconium phosphate fine powder added is too little. This ultimately results in the compressive strength of the pharmaceutical glass molding rotary tube prepared in Comparative Examples 2-4 being reduced to 105-113MPa, the number of 1100°C water-cooled thermal shock tests being reduced to <10 times, the thermal shock resistance being greatly reduced, and the dynamic erosion rate at 1300°C being increased to 0.3-0.36mm / 24h, and the foaming index being increased to 3-4. Therefore, the erosion resistance of the pharmaceutical glass molding rotary tube products prepared in Comparative Examples 2-4 is reduced, and bubbles will appear during the molding process, reducing the qualified rate of the rotary tube. In Comparative Examples 5-6, magnesium phosphate fine powder was used in place of zirconium phosphate fine powder or aluminum phosphate fine powder in the composite phosphate fine powder, resulting in an increase in apparent porosity to 24% and 23.5% after sintering, 9 and 10 times of 1100°C water-cooled thermal shock test, and a significant decrease in glass erosion resistance and foaming performance. The dynamic erosion rate at 1300°C increased to 0.5 mm / 24h and 0.41 mm / 24h, and the foaming index increased to 6 and 5. It is speculated that the reason is that magnesium phosphate is a weakly alkaline compound, which has a certain chemical reaction with the acidic glass liquid, and the generated gas is mixed in the pores in the material and enters the glass liquid, eventually generating bubbles.

[0090] In summary, the present invention adopts composite phosphate fine powder combined with corundum material to manufacture a rotary tube product for medicinal glass molding, which has good thermal shock resistance, high glass corrosion resistance and low foaming, which is beneficial to prolonging the service life of the rotary tube for medicinal glass molding and improving the yield of the rotary tube for medicinal glass molding.

Claims

1. A rotary tube for low foaming medicinal glass molding, characterized in that: Made of the following components in percentage by mass, the total mass of the remaining components except the binder is 100%, and the binder is calculated as a percentage of the total mass of the remaining components: Corundum particles 50-65%; Corundum fine powder 15-25%; Compound phosphate fine powder 10-25%; Sintering agent 3-5%; Binder 2-5%; The composite phosphate fine powder is a mixture of zirconium phosphate fine powder and aluminum phosphate fine powder, and the mass ratio of zirconium phosphate fine powder to aluminum phosphate fine powder is (1-3): (1-3); the sintering promoter is clay; and the binder is calcium lignin sulfonate solution or magnesium lignin sulfonate solution.

2. The low-foaming pharmaceutical glass molding rotary tube according to claim 1, characterized in that: Among the corundum particles, the mass of the corundum particles with a particle size of 0.5-1 mm accounts for 20-30% of the total mass of the remaining components except the binder, and the mass of the corundum particles with a particle size of 0.1-0.5 mm accounts for 25-35% of the total mass of the remaining components except the binder.

3. The low-foaming pharmaceutical glass molding rotary tube according to claim 1, characterized in that: The particle size of the corundum fine powder is ≤0.088 mm.

4. The low-foaming pharmaceutical glass molding rotary tube according to claim 1, characterized in that: The clay particle size is ≤45 μm.

5. The method for preparing a low-foaming pharmaceutical glass forming rotary tube according to any one of claims 1 to 4, characterized in that: The following steps are involved: S1: Pour the corundum particles, composite phosphate fine powder and sintering agent into a strong mixer, dry mix for 2-3 minutes, then add the binder and mix for 3-5 minutes; S2 Add corundum fine powder and mix for 3-5 minutes to obtain mud; S3 uses a 2mm sieve to remove mud agglomerates; S4 The sieved clay is poured into a mold and isostatically pressed into a green body with a fixed shape and size; S5: drying the green body; S6 The dried green body is loaded into a kiln for sintering; S7 processes the sintered green body into a rotating tube for forming low-foaming pharmaceutical glass.

6. The method for preparing a low-foaming pharmaceutical glass forming rotary tube according to claim 5, characterized in that: In step S5, the drying temperature is 110-180° C., and the drying time is 6-24 hours.

7. The method for preparing a low-foaming pharmaceutical glass forming rotary tube according to claim 5, characterized in that: In step S6, the sintering temperature is 1400-1550° C., and the sintering time is 5-24 hours.

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