A kind of microcrystalline glass and its preparation method and application

Abstract

The invention discloses a glass-ceramic and a preparation method and application thereof, belonging to the technical field of optical fiber connection materials. The powder raw materials are mechanically mixed and wet-milled to obtain glass slurry, acrylamide, NN-methylenebisacrylamide and deionized water are stirred and mixed to obtain a tackifier, the tackifier is added to the glass slurry, ball-milled and mixed, and the viscosity is adjusted to 0.3-0.6 Pa·s, filtered, an initiator and a catalyst are added, and the mixture is uniformly injected into a mold, solidified, demoulded, dried, and a blank is obtained, and the blank is melted and annealed to obtain the glass-ceramic; the blank is injection-molded by a mold, and is not easy to shrink and deform during the melting process; rare earth ions are helpful to increase the crystallization efficiency and optical transmittance of the glass-ceramic, and are helpful to increase the hardness of the glass-ceramic and reduce reflected light, and the glass-ceramic is applied in an optical fiber connector ferrule to increase the return loss and reduce the influence of reflected light on the signal, and has practical application value.

Description

Technical Field

[0001] The present invention belongs to the technical field of optical fiber connection materials, and in particular relates to a microcrystalline glass and a preparation method and application thereof. Background Art

[0002] Glass-ceramics, also known as microcrystalline jade or ceramic glass, is a basic glass with a specific composition and a crystal nucleating agent. When subjected to a crystallization heat treatment at a certain temperature regime, a large number of tiny crystals are uniformly precipitated in the glass, forming a dense multiphase complex of microcrystalline phase and glass phase. Glass-ceramics has the dual characteristics of glass and ceramics. Like ceramics, it is composed of crystals, so glass-ceramics is brighter than ceramics and has stronger toughness than glass.

[0003] Commonly used methods for preparing microcrystalline glass include sintering, calendering, casting and sol-gel, among which sintering is the most widely used. Microcrystalline glass prepared by sintering is prone to cracks during annealing; the advantages of calendering are high product density, no pores, high flexural strength, continuous manufacturing process, and full-line automated production, but crystallization is difficult to control and the yield is low; casting can be cast into special-shaped glass, the product has high density, no pores, and high compressive strength, but the disadvantages are high quality requirements, large mold loss, and high production cost; the sol-gel method uses metal organic salts as raw materials, hydrolyzes and condenses into a non-flowable gel state, and then gradually heat treats it to obtain microcrystalline glass. Its advantages are low preparation temperature, which can avoid the volatilization of some components and reduce pollution, but the gel is prone to shrinkage and deformation during the sintering process.

[0004] With the development of optical fiber communication technology, the requirements for related electronic devices are getting higher and higher. Glass-ceramics have begun to be used in the preparation of optical fiber connector ferrules. Compared with traditional zirconium oxide materials, the thermal expansion coefficient and hardness of lithium-based glass-ceramics are more compatible with optical fibers, easy to process with high precision, and have excellent environmental stability. However, glass-ceramics are prone to deformation, bubbles and other defects during the preparation of special-shaped glass, which has a certain impact on the high-speed transmission of signals. Summary of the invention

[0005] The object of the present invention is to provide a glass-ceramic and a preparation method and application thereof, so as to solve the problems in the background technology.

[0006] The purpose of the present invention can be achieved through the following technical solutions:

[0007] A method for preparing glass-ceramics comprises the following steps:

[0008] Step 1: Add the powder raw materials into a V-type mixer for mechanical mixing to obtain a mixed powder; mix the mixed powder and deionized water in a mass ratio of 2:1 by ball milling, and obtain a glass slurry with a water content of 40% after filtering;

[0009] Step 2: Stir and mix acrylamide, NN-methylenebisacrylamide and deionized water to obtain a thickener;

[0010] Step 3: adding a tackifier to the glass slurry, mixing by ball milling and adjusting to a viscosity of 0.3-0.6 Pa·s, filtering to obtain a mixed slurry;

[0011] Step 4: Add initiator and catalyst to the mixed slurry, mix well and inject into the mold, close the mold, hold pressure and solidify, demould, dry, and obtain a green body;

[0012] Step 5: Melt the blank at 1400-1550°C for 2.5-5h, then cool to room temperature, transfer to a muffle furnace, anneal and crystallize at 420-450°C for 5-7h, and obtain microcrystalline glass after cooling to room temperature.

[0013] Furthermore, the powder raw material includes, by weight, 45-60 parts of SiO2, 10-18 parts of Al2O3, 3-6 parts of TeO2, 1-4 parts of K2O, 0.5-3 parts of Li2O, 0.5-3 parts of GeO2, 5-10 parts of MgO, and 5-15 parts of a nucleating agent.

[0014] Furthermore, the nucleating agent is any one of ZrO2 and TiO2.

[0015] Furthermore, the usage ratio of acrylamide, NN-methylenebisacrylamide and deionized water in the tackifier is 20-30g:0.2-1g:90g.

[0016] Furthermore, the catalyst is ethylenediamine and the initiator is ammonium persulfate.

[0017] Furthermore, the amount of the catalyst used is 0.2-0.5wt% of the mixed slurry, and the amount of the initiator used is 0.2-0.4wt% of the mixed slurry.

[0018] Beneficial effects of the present invention:

[0019] In the preparation process of the microcrystalline glass of the present invention, each powder raw material is wet-milled, which helps to grind each powder raw material to the nanometer level, and then the powder raw material is mixed with the thickener by ball milling. The filtration process in the subsequent step can remove the complex formed by acrylamide and powder particles, ensure the uniformity of the mixed slurry, and prevent the cracking of the blank after solidification and drying. In addition, the blank is injection-molded by a mold, which helps to prepare special-shaped glass. Compared with the sol-gel method, the dense blank formed is not easy to shrink and deform during the melting process.

[0020] In the present invention, the powder raw material forms a uniform phase-separated glass network structure during the melting process, which is beneficial to the diffusion of alkali metal oxides in the phase-separated glass network structure. SiO2 crystal phase, LiSiO3 crystal phase and Li2O·Al2O3·4SiO2 crystal phase can be precipitated during the annealing process. GeO2 and TeO2 in the powder raw material are rare earth oxides, and the corresponding rare earth ions move slowly, while the diffusion and rearrangement speed of the remaining small-radius ions is fast, so the rare earth ions are easily wrapped by the precipitated crystal phase, which helps to increase the crystallization efficiency and optical transmittance of the prepared microcrystalline glass, helps to increase the hardness of the microcrystalline glass and reduce reflected light. The application in the optical fiber connector ferrule can increase the return loss and reduce the influence of reflected light on the signal, and has practical application value. DETAILED DESCRIPTION

[0021] The following will be combined with the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0022] Example 1

[0023] The preparation of glass-ceramics comprises the following steps:

[0024] Step 1: prepare 450g SiO2, 100g Al2O3, 30g TeO2, 10g K2O, 5g Li2O, 5g GeO2, 50g MgO, and 50g TiO2, add the powder raw materials into a V-type mixer for mechanical mixing to obtain a mixed powder; put the mixed powder and deionized water into a wet ball mill at a mass ratio of 2:1 for ball milling and mixing, grind each powder raw material to a nanometer level, and filter out particles with larger particle sizes through a scraper filter driven by a discharge pump to obtain a glass slurry with a water content of 40%;

[0025] Step 2: 200 g acrylamide, 2 g NN-methylenebisacrylamide and 900 g deionized water are stirred and mixed with a liquid mixer to obtain a tackifier;

[0026] Step 3: adding a thickener to the glass slurry, mixing and blending the mixture by a wet ball mill to a viscosity of 0.3 Pa·s, and filtering the mixture by a scraper filter driven by a discharge pump to remove a small amount of unrefined complex formed by acrylamide and the slurry to obtain a mixed slurry;

[0027] Step 4: Add 1g of ammonium persulfate and 1g of ethylenediamine to 0.5kg of the mixed slurry, mix them evenly with a paddle mixer, and then inject them into the mold. After closing the mold, maintain the pressure and solidify under a pressure of 10MPa, demold, and dry in an oven at 80°C for 12h to obtain a green body;

[0028] Step 5: Melt the blank in an electric melting furnace at 1400°C for 2.5 hours, then cool to room temperature, transfer to a muffle furnace for annealing and crystallization at 420°C for 5 hours, and obtain microcrystalline glass after cooling to room temperature.

[0029] Example 2

[0030] The preparation of glass-ceramics comprises the following steps:

[0031] Step 1: prepare 500g SiO2, 140g Al2O3, 45g TeO2, 25g K2O, 15g Li2O, 15g GeO2, 8gMgO, and 10g ZrO2, add the powder raw materials into a V-type mixer for mechanical mixing to obtain a mixed powder; put the mixed powder and deionized water into a wet ball mill at a mass ratio of 2:1 for ball milling and mixing, grind each powder raw material to a nanometer level, and filter through a scraper filter to remove particles with larger particle sizes under the drive of a discharge pump to obtain a glass slurry with a water content of 40%;

[0032] Step 2: 250 g of acrylamide, 6 g of NN-methylenebisacrylamide and 900 g of deionized water were stirred and mixed using a liquid mixer to obtain a tackifier;

[0033] Step 3: adding a thickener to the glass slurry, mixing and blending the mixture by a wet ball mill to a viscosity of 0.4 Pa·s, and filtering the mixture by a scraper filter under the drive of a discharge pump to remove a small amount of unrefined complex formed by acrylamide and the slurry to obtain a mixed slurry;

[0034] Step 4: Add 1.5 g of ammonium persulfate and 1.5 g of ethylenediamine to 0.5 kg of the mixed slurry, mix well with a paddle mixer, and inject into the mold. After closing the mold, maintain pressure and solidify under a pressure of 10 MPa, demold, and dry in an oven at 80° C. for 12 hours to obtain a green body;

[0035] Step 5: Melt the blank in an electric melting furnace at 1500°C for 3 hours, then cool to room temperature, transfer to a muffle furnace for annealing and crystallization at 430°C for 6 hours, and obtain microcrystalline glass after cooling to room temperature.

[0036] Example 3

[0037] The preparation of glass-ceramics comprises the following steps:

[0038] Step 1: prepare 600g SiO2, 180g Al2O3, 60g TeO2, 40g K2O, 30g Li2O, 30g GeO2, 100g MgO, and 150g ZrO2, add the powder raw materials into a V-type mixer for mechanical mixing to obtain a mixed powder; put the mixed powder and deionized water into a wet ball mill at a mass ratio of 2:1 for ball milling and mixing, grind each powder raw material to a nanometer level, and filter out particles with larger particle sizes through a scraper filter driven by a discharge pump to obtain a glass slurry with a water content of 40%;

[0039] Step 2: 300 g acrylamide, 10 g NN-methylenebisacrylamide and 900 g deionized water are stirred and mixed with a liquid mixer to obtain a tackifier;

[0040] Step 3: adding a thickener to the glass slurry, mixing and blending the mixture by a wet ball mill to a viscosity of 0.6 Pa·s, and filtering the mixture through a scraper filter driven by a discharge pump to remove a small amount of unrefined complex formed by acrylamide and the slurry to obtain a mixed slurry;

[0041] Step 4: Add 4g of ammonium persulfate and 5g of ethylenediamine to 1kg of the mixed slurry, mix them evenly with a paddle mixer, and then inject them into the mold. After closing the mold, maintain the pressure and solidify under a pressure of 10MPa, demold, and dry in an oven at 80°C for 12h to obtain a green body;

[0042] Step 5: Melt the blank in an electric melting furnace at 1550°C for 5 hours, then cool to room temperature, transfer to a muffle furnace for annealing and crystallization at 450°C for 7 hours, and obtain microcrystalline glass after cooling to room temperature.

[0043] Example 4

[0044] According to the preparation method of Example 4, the final mold was replaced with a fiber optic connector ferrule mold to prepare a connector ferrule with a diameter of 2.499 mm. After being assembled with a high-purity quartz glass optical fiber, the end face was polished with 10 μm, 5 μm, 3 μm and 1 μm diamond grinding papers in sequence, and finally assembled into an ST-type fiber optic connector.

[0045] Example 5

[0046] According to the preparation method of Example 2, the final mold was replaced with a fiber optic connector ferrule mold to prepare a connector ferrule with a diameter of 2.499 mm. After being assembled with a high-purity quartz glass optical fiber, the end face was polished with 10 μm, 5 μm, 3 μm and 1 μm diamond grinding papers in sequence, and finally assembled into an ST-type fiber optic connector.

[0047] Example 6

[0048] According to the preparation method of Example 3, the final mold was replaced with a fiber optic connector ferrule mold to prepare a connector ferrule with a diameter of 2.499 mm. After being assembled with a high-purity quartz glass optical fiber, the end face was polished with 10 μm, 5 μm, 3 μm and 1 μm diamond grinding papers in sequence, and finally assembled into an ST-type fiber optic connector.

[0049] Comparative Example 1: Based on Example 3, GeO2 and TeO2 are not added to the mixed powder, and the method in Example 6 is combined, and the other steps remain unchanged to prepare an ST type optical fiber connector.

[0050] The return loss (RL) test of the ferrules of the ST-type optical fiber connectors in Examples 4 to 6 and Comparative Example 1 was performed according to IEC-61300-3-6-2008. The results are shown in Table 1:

[0051] Table 1

[0052] project Example 4 Example 5 Example 6 Comparative Example 1 RL / dB 75 76 78 47

[0053] It can be seen from Table 1 that the return loss of the optical fiber connector ferrule in Examples 4 to 6 is higher.

[0054] It should be noted that, in this article, terms such as "comprises", "includes" or any other variations thereof are intended to cover non-exclusive inclusion, so that a process, method, article or apparatus that includes a series of elements includes not only those elements, but also other elements not explicitly listed, or also includes elements inherent to such process, method, article or apparatus.

[0055] Although embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that various changes, modifications, substitutions and variations may be made to the embodiments without departing from the principles and spirit of the present invention, and that the scope of the present invention is defined by the appended claims and their equivalents.

Claims

1. A method for preparing glass-ceramics, characterized in that: The steps include: Step 1: Mechanically mix the powder raw materials into mixed powder, mix the mixed powder and deionized water by ball milling, and filter to obtain glass slurry; Step 2: Stir and mix acrylamide, N,N-methylenebisacrylamide and deionized water to obtain a thickener; Step 3: adding a tackifier to the glass slurry, mixing by ball milling and adjusting to a viscosity of 0.3-0.6 Pa·s, filtering to obtain a mixed slurry; Step 4: Add initiator and catalyst to the mixed slurry, mix well and inject into the mold, close the mold, hold pressure and solidify, demould, dry, and obtain a green body; Step 5: melting the body at 1400-1550° C. for 2.5-5 hours, annealing and crystallizing at 420-450° C. for 5-7 hours after cooling, and cooling to obtain microcrystalline glass; The powder raw materials include SiO2 45-60 parts, Al2O3 10-18 parts, TeO2 3-6 parts, K2O 1-4 parts, Li2O 0.5-3 parts, GeO2 0.5-3 parts, MgO 5-10 parts and nucleating agent 5-15 parts by weight; The nucleating agent is any one of ZrO2 and TiO2.

2. The method for preparing glass-ceramics according to claim 1, characterized in that: The mass ratio of the mixed powder and deionized water used in step 1 is 2:

1.

3. The method for preparing glass-ceramics according to claim 1, characterized in that: The water content of the glass slurry in step 1 is 40%.

4. The method for preparing glass-ceramics according to claim 1, characterized in that: The usage ratio of acrylamide, N,N-methylenebisacrylamide and deionized water in step 2 is 20-30g:0.2-1g:90g.

5. The method for preparing glass-ceramics according to claim 1, characterized in that: In step 4, the catalyst is ethylenediamine and the initiator is ammonium persulfate.

6. A glass-ceramic, characterized in that: It is prepared by the preparation method described in any one of claims 1 to 5.

7. Use of the microcrystalline glass according to claim 6 in an optical fiber connector ferrule.