JP5214138B2 - Glass product and its manufacturing method - Google Patents

Description

  The present invention relates to glass compositions with little variation in basic properties within any given lot, and to products made therefrom.

  In glass applications such as liquid crystal panels, for example optical communication devices such as optical filters and optical switches, recording media, halogens and high intensity discharge (HID) lamps, consistency of glass substrate characteristics is extremely important. High power laser systems use multiple large optical quality glasses, sometimes thousands of large laser glass pieces, and it is essential that the glass pieces have consistent optical quality. Glass compositions, like fused quartz compositions, are characterized by a few basic properties that affect the manufacture or properties of products using the composition, namely viscosity, percent transmission, OH level, to name a few. . The effect of OH (hydroxyl group) on the viscosity of glass or quartz is widely known. For example, FIG. 1 shows the viscosity curves of high purity quartz made at various OH concentrations. As can be seen from the figure, the viscosity of the glass greatly decreases as the hydroxyl group concentration increases. Variation of glass or quartz OH levels from batch to batch or from lot to lot results in inconsistent manufacturability and product quality. From the lamp manufacturer's point of view, fluctuations in glass properties affect the yield of high-speed lamp production lines and require undesirably frequent adjustments to the equipment that caused the fluctuations in glass properties.

  Almost all arc discharge lamps, such as tungsten halogen lamps, and many high-intensity filament lamps emit ultraviolet (UV) light that can be harmful to the human eye and skin. As disclosed in Patent Document 1, Patent Document 2, Patent Document 3, Patent Document 4 and Patent Document 5, the lamps developed so far are UV and visible light surrounded by a vitreous envelope of fused silica. Has a light source that emits both. U.S. Patent Nos. 6,099,086 and 5,048,83 are in the form of tubes or rods used to make lamps and absorb fused quartz compositions containing materials called UV absorbing materials or dopants, such as UV radiation. A lamp envelope with characteristics is disclosed.

  Patent Document 9 discloses a composition having desirable characteristics such as a specific coefficient of linear thermal expansion, fracture toughness, and a predetermined surface hardness, and useful for forming a glass substrate used for an information recording medium. In applications that make bulk glass products such as fiberglass, it is also useful that the glass composition be consistent to obtain the desired range of properties for viscosity, humidity resistance, and the like. Patent Document 10 discloses a composition for making a glass fiber filter for use in a microelectronic clean room environment.

Depending on the bulk volume of the raw material from which the glass composition is made, there is a wide batch-to-batch variation in the glass composition as well as the properties of products made from prior art glass compositions. It is important that the glass composition has consistent properties so that the variation characteristics of the product being produced are uniform or narrow. In addition, the consistent properties allow manufacturers to operate lines with high or low productivity, and with little or no adjustment to obtain consistently good glass products.
US Pat. No. 2,895,839 US Pat. No. 3,148,300 US Pat. No. 3,848,152 US Pat. No. 4,307,315 US Pat. No. 4,361,779 US Patent 2,221,709 US Pat. No. 5,569,979 US Pat. No. 6,677,260 US Patent Publication 20040063564A1 US Patent Publication 20020077243A1

  The present invention relates to a new glass composition and a method for producing glass products with uniform properties as measured by standard deviation.

In one aspect, the softening temperature of the present invention relates to a glass composition containing glass article of one lot, the glass composition contains SiO ₂ 40 to 99 wt%, the glass composition, 600 ° C. to 1650 The standard deviation of the softening temperature measurement obtained from 10 or more samples randomly selected from the lot of glass products produced is in the range of 10 ° C.

In another aspect, the present invention relates to a process for making a glass product, the process: a) dispersing agent 0.02 to 0.50 wt% and _{Al 2 O 3, TiO 2,} CeO 2, Nd 2 O 3, B 2 Of O ₃ , BaO, SrO, CaO, MgO, Na ₂ O, K ₂ O, Li ₂ O, Sb ₂ O ₃ , Y ₂ O ₃ , Co ₃ O ₄ , Cu ₂ O, Cr ₂ O ₃ and mixtures thereof Forming a first blend with 1 to 25% by weight of a dopant selected from the group of metal oxides, provided that the dispersant has a BET of 50 to 400 m ² / g and an average particle size of less than 1 μm a metal oxide; and then b) the first one blending step blending 92 to 99 wt% of SiO ₂ forming the quartz mixture; step for generating a lysate of the molten glass from c) mixtures thereof; and ) Comprises the step of passing the molten glass along the tool for forming the glassware. In one embodiment, the glassware is in the form of a tube, rod, or blank. In a second embodiment, the fumed metal oxide is selected from at least one of silica or metal oxide already present in the dopant.

The invention further SiO ₂ 92 to 99 _{wt%, Al 2 O 3, CeO} 2, TiO 2, Nd 2 O 3, B 2 O 3, BaO, SrO, CaO, MgO, Na 2 O, K 2 O, 1-8% by weight of a dopant selected from the group of metal oxides Li ₂ O, Sb ₂ O ₃ , Y ₂ O ₃ , Co ₄ O ₄ , Cu ₂ O, Cr ₂ O, and mixtures thereof; and a BET of 50 ~400m a ² / g, relates glassware an average particle size consisting of fumed metal oxides is a 1μm from 0.02 to 0.50 wt%, fumed metal oxides are metal oxides present in the SiO ₂ or the dopant The viscosity of multiple products prepared from the same batch exhibits a standard deviation of less than 10 ° C.

As used herein, an approximate representation can be applied to modify any quantitative indication that may change without causing a change in the underlying function to which the representation relates.
Thus, a value that is modified by term (s) such as “about” and “substantially” may not be limited to the exact value specified.

  As used herein, the term “functionalized” refers to a coating of a dopant component comprising silica and a dispersant of the present invention, including “surface functionalized”, “functionalized surface”, “coated”, “coated”. “Surface treated” or “treated” can be used interchangeably. As used herein, “coating agent” is used interchangeably with “dispersing” agent.

  Various terms can be used to describe compositions or articles of different materials (different silica concentrations), but as used herein, the term “glass” refers to a composition, part, product, or natural or With reference to an article formed by dissolving a mixture of synthetic sand (silica), it can be used interchangeably with “quartz glass”, “quartz” or “fused quartz”. Either natural or synthetic sand (silica) or both can be used in the compositions of the present invention, the term is naturally occurring crystalline silica such as sand / rock, synthetically produced silicon dioxide (silica) Is used to denote a composition consisting of either or a mixture of both. The term “sand” refers to either natural sand or synthetic sand or a mixture of both and can be used interchangeably with silica.

  As used herein, the term “lot” refers to a single batch of sand of at least 100 kg in the total composition of sand and other additives when applied to a batch operation to produce the glassware of the present invention. References are made to glass products made from the material. When applied to a continuous process for producing glassware, the term lot refers to a glassware produced continuously from one process and having a total weight of at least 100 kg.

  In one embodiment, the present invention relates to an article formed from the same lot of composition, eg, fiberglass, tube, rod, through a dispersant / coating agent that aids adhesion of the dopant to the sand grains. , Blank, plate, etc. The dispersant maximizes the homogeneity of the composition within the same lot so that variations in properties such as viscosity, OH-, etc. of articles or parts made from the same lot are minimized. Articles made from the composition of the present invention with minimal property variation can then be melted and stretched to form or adjust to the final glass product.

Sand component :
Depending on the end use, the sand (SiO ₂ ) material can be either synthetic sand or natural sand or a mixture thereof. In one embodiment, the amount of SiO ₂ is in the range 40 to 75%. In a second embodiment, the amount is 70-95% by weight. In a third embodiment, the glass consists of a light transmissive, vitreous component having a SiO ₂ content of at least 90% by weight. In a fourth embodiment of the refractory quartz composition, SiO ₂ is used at least 95% by weight. In the fifth embodiment, the amount of SiO ₂ is in the range of 40-99%.

Dispersant component :
In one embodiment, the agent is alumina, silica, titania, ceria, neodymium oxide, and a fumed metal oxide selected from the group consisting of mixtures thereof, in its BET value ^{50m 2} / ^g~1000m 2 / g Yes, the particle size is less than 25 microns. Fumed metal oxides are produced using processes known in the art, such as hydrolysis of a suitable feedstock vapor (such as silicon tetrachloride for fumed silica) in a hydrogen-oxygen flame.

The surface area of the metal oxide is S.I. Brunauer, P.M. H. Emmet and I.M. Teller's nitrogen adsorption method, J. MoI. Am. Chemical Society, Vol. 60, p. 309 (1938), and is generally called BET. In one embodiment, BET dispersant is 100 m ² / g to about 400m ² / g. In the second embodiment, the average particle size of the fumed metal oxide dispersant is 15 μm or less. In the third embodiment, the average particle size of the fumed metal oxide is less than 1.0 μm. In the fourth embodiment, BET value of fumed metal oxides is ^{50m 2} / ^g~100m 2 / g, an average particle diameter of 0.1 to 0.5 [mu] m.

    The dispersant is added in an amount ranging from 0.02 to 0.50% by weight (based on the total weight of the final glass composition) relative to the glass composition. In one embodiment, the dispersant is added to the sand mixture in an amount ranging from 0.04 to 0.30% by weight. In a second embodiment, 0.05-0.15% by weight. In a third embodiment, 0.05-0.10% by weight.

  In one embodiment, the dispersant is added directly to the glass composition along with the dopant. In a second embodiment, the dispersant is premixed with at least one of the dopant (s) or a portion of the dopant (s) to form a masterbatch and then added to the sand mixture. In a third embodiment, the dispersant is mixed with some or all of the selected dopant (s) that form the masterbatch, and then the masterbatch is added to the sand mixture and other dopants. In a fourth embodiment, the dispersant is mixed with all or some of the selected dopants as well as some sand to form a masterbatch, which is then added to the final sand mixture.

In one embodiment, the dispersant is untreated fumed silica. In a second embodiment, Al ₂ O ₃ is used as a dopant and the dispersant is fumed alumina. In a third embodiment, CeO2 is added as a dopant and fumed ceria is used as a dispersant. In a fourth embodiment, one of the dopants used is Nd ₂ 0 ₃ and a mixture of fumed neodymium oxide and fumed silica is used as the dispersant. In yet another embodiment, regardless of the dopant used, the dispersant is a fumed metal oxide that has little adverse effect on the properties of the glass product, i.e. fumed alumina, silica, titania, ceria, neodymium oxide, And a mixture thereof.

Dopant component (s) :
Add a number of different dopants and mixtures to the silicate or borosilicate glass of the substrate, depending on the end use and desired properties, such as high intensity discharge lamps, tungsten halogen lamps, automotive polish, optical lenses, etc. Can do. Examples of dopants include, but are not limited to, metals, metal oxides, and alkali metal oxides known in the art, and the amount of each dopant is 0.1-25% by weight. .

  In one embodiment, dopants are added to the glass to change color and transmission properties among other properties. In the second embodiment, the total amount of dopant is in the range of 0.1 to 10% by weight. In a third embodiment, each dopant is in the range of 0.1-8% by weight. In a third embodiment, each dopant is in the range of 0.1-5% by weight.

In one embodiment, the dopant is neodymium oxide Nd ₂ O ₃ . Neodymium has long been known as a colorant like other rare earth elements, has an absorption spectrum that extends in both the visible and invisible regions, and moves substantially unchanged into a base compound such as glass. Neodymium absorbs light in the yellow region of the visible spectrum at about 568-590 nm. As a result, the light passing through the glass containing neodymium makes the surrounding environment stand out for red and green tones. Furthermore, the glass containing neodymium improves visibility in foggy weather.

In the second embodiment, the dopant is boron oxide B ₂ O ₃ . The amount of B ₂ O ₃ can be carefully adjusted to give the glass a sufficiently low viscosity to facilitate its melting, but does not cause the glass to expand. In a third embodiment, the dopant is an alkali oxide, for example Na ₂ O, K ₂ O, Al ₂ O in glass borosilicate compositions (SiO ₂ + B ₂ O ₃ ) having a low expansion coefficient and a low softening temperature. ₃ or a mixture thereof. In a fourth embodiment, the dopant is CeO ₂ in an amount of 0.1-5% by weight. Cerium is the only rare earth element that absorbs ultraviolet light but does not exhibit absorption in the visible region of the spectrum. Further, in a fifth embodiment, titanium or titanium oxide can be added, and the addition of titanium sometimes produces a tan glass. In the sixth embodiment, the dopant is composed of europium oxide Eu ₂ O ₃ alone or in combination with other dopants such as TiO ₂ and CeO ₂ . In a seventh embodiment, dopants such as CaO and / or magnesium oxide MgO can be added to provide stability to the composition.

In one embodiment of the glass composition containing 95-99.9 wt% SiO ₂ excluding the dispersant, the dopant is added as Al ₂ O _{3 in} the range of 0.1-5 wt% and other impurities Is added in an amount not exceeding 150 ppm (total). In a second embodiment, the composition is 95 to 99.9 wt% of _SiO 2, _Al 2 _O 3 as a 0.1 to 5 wt% of dopant, 0.1～400Ppm titanium (element), 0. Consists of 1 to 4000 cerium (in elemental form or CeO ₂ ) and other impurities not exceeding 150 ppm (total). In a third embodiment, the composition is 95 to 99.9 wt% of _SiO 2, _Al 2 _O 3 as a 0.1 to 5 wt% of dopant, 0.1～400Ppm titanium (element), 0. 1 to 4000 cerium (elemental form or in CeO ₂ ), 0.01 to ₂ wt% Nd ₂ O ₃ , consisting of other impurities not exceeding 150 ppm (total).

In yet another embodiment, except the dispersing agent, for the envelope of tungsten-halogen lamps and other high temperature lamps, the composition is essentially in weight percent, 90.5 to 95.7% of _SiO 2, 2.8-3.0% B ₂ O ₃ , 0.7-1.7% Al ₂ O ₃ , 0.4-4.5% Nd ₂ O ₃ , and 0.1-1% consisting of CeO _2. Further, in another embodiment of making a halogen lamp envelope, the composition is essentially 55% to 66% SiO ₂ , 0 to 13% B ₂ O ₃ , 14 by weight, excluding the dispersant. 18% of _Al 2 _O 3, 0~13% of BaO, 0 to 4% of SrO, 0 to 13% of CaO, 0 to 8% of MgO, 0.4 to 4.5% of _Nd 2 _{O 3} , and it consists of 0.1% to 1% of CeO _2. In another embodiment of the sealed beam incandescent headlamps glass composition, except for the dispersant, the composition is essentially 64 to 85% of _SiO 2, 11 to 28 percent of _B 2 O, 0.5 to 8 0.5% Al ₂ O ₃ , 0-3.5% BaO, 0-1.5% CaO, 0-7.5% Na ₂ O, 0-9.5% K ₂ O, 0 1.5% of _Li 2 O, 0 to 1.5% of _Sb 2 _O 3, _0.4~4.5% of _Nd 2 _{O 3,} and consists of 0.1% to 1% of CeO _2.

In one embodiment of the glass composition that absorbs red light in the range of 560～620Nm, except for the amount of additive dispersant composition of _SiO 2, 0.5 to 1.2 parts by weight of 95 to 110 parts by weight CeO _2, 0.5 to 2.5 parts by weight of _Nd 2 _O 3, 0.1 to 1 part by weight of _{Al 2 O 3, Eu 2 O} 3 optionally in 0.001 parts by weight, 0. It consists of 001 to 0.1 parts by weight of TiO ₂ and 0.001 to 0.5 parts by weight of BaO.

In one embodiment of a glass composition for producing clean room HEPA and ULPA filters, the composition contains less than 1 wt% boron, except 0.05-0.10 wt% of fumed silica as a dispersant; 5.5 -18 wt% barium oxide; 10-14.5 wt% alkali oxide; 4-8 wt% alumina; 1-9 wt% alkaline earth oxide; 2-6 wt% zinc oxide; 0 0.1 to 1.5 wt% fluorine; and the balance silica. Furthermore, in another embodiment of a glass composition for a glass part of a lamp having excellent electrical insulation properties, the composition is 55 to 80, except for 0.02 to 0.50 wt% fumed alumina as a dispersant. wt% of _SiO 2; 0.5 to 5 wt% of _Al 2 _O 3; 0~5 wt% of _B 2 _O 3; _2~15 wt% of _Na 2 O; 0 to 5 wt% of _Li 2 O; and it consists 1-15 wt% of _{K 2 O,} the total content of Na 2 O, _Li 2 O, and _{K 2} O is within the range of 3 to 25 wt%. Furthermore, in another glass composition for optical applications, such as a gradient index lens, the composition is 40-65 mol% SiO ₂ except for 0.02-0.50 wt% fumed silica as a dispersant; MgO up to 22 mol%; 10 mol% of _TiO 2 2 to 18 mol% of _Li 2 O; 2 to 20 mol% of _Na 2 O; and CaO, 1 to 15 of any of the SrO and BaO Consists of mol%.

Glass composition / product manufacturing process :
The use of a dispersant in the composition of the present invention promotes the blending of the dopant in the sand material and thus homogenizes the glass product. The composition can be manufactured by a batch process (single melt process) or a continuous melt process.

  In one embodiment of the batch operation, the glassware is manufactured in the form of a sand barrel or bag from a batch of sand, each barrel or bag weighing at least 100 pounds. In another embodiment, the glassware is made from a batch of at least 100 kg of sand material for each batch, and the sand is supplied in barrels of 100 kg size. In yet another embodiment, sand is supplied in 300 pound batches for each bag or barrel, thus producing glass articles from each single batch of at least 300 pounds.

In one embodiment, a dispersant, i.e. a fumed metal oxide such as fumed silica, fumed alumina, etc., is first mixed with a single dopant, a small number of dopants, or 20-100% of all dopants, and a masterbatch, in other words Form a concentrate. The fumed metal oxide dispersant can be the same or different metal oxide as the dopant material. The mixing / blending can be performed with processing equipment known in the art, such as a blender, high intensity mixer, etc., for a time sufficient to completely coat the dopant with the dispersant. In one embodiment, a mixture of fumed silica as a dispersant is mixed with a dopant such as Al ₂ O ₃ , CeO ₂ , Nd ₂ O ₃ in a Turbula® mixer for 1-5 hours to form a masterbatch. Without being bound by theory, it is believed that fumed silica acts as a sand grain “coating” agent, attracts smaller particulate matter of dopants such as aluminum oxide, and thus provides more uniform mixing.

  In the next step, the masterbatch containing the coated dopant (s) is added to the natural / synthetic sand material and any remaining uncoated dopant, if any, and thoroughly mixed in a tumbler, sand muller, etc. To do.

In one embodiment of the invention, the homogenous mixture is calcined or heated in the temperature range of 500-1500 ° C. for a sufficient time, for example 1 / 2-4 hours, to dry the sand. The mixture is then melted at a sufficiently high temperature to form a glass product. The temperature depends on the glass component, and in the quartz component (containing more than 95% SiO ₂ ), the mixture is melted in the temperature range above 2000 ° C. and below 2500 ° C. to give a vitreous material. In one embodiment, the mixture is continuously fed to a high temperature induction (electric) furnace operating in the temperature range of 1400-2300 ° C. to form tubes and rods of various sizes. In another embodiment, the mixture is fed into a mold and flame melting is used to dissolve the composition, and the dissolved mixture is directed to a mold that forms glass particles.

  In one embodiment, the glassware can be manufactured in a continuous tube drawing manner, for example, by any process known in the art, including a Danner process, a Vero process, a continuous drawing process or a modification process.

Glass products from the composition of the present invention :
While not theoretically constrained, a dispersant having the form of a fumed metal oxide with a large surface area functions as a blending agent, helping the sticking or sticking of the dopant to the sand grains, allowing for homogeneous mixing; It is believed that the variation in glass product properties of products derived from the same batch of sand is extremely small. Glass products as an intermediate type of glass tubes, halogen lamp bulbs or water treatment lamps; solid glass rods or preforms for the manufacture of lamp envelopes; blanks, glass plates or automotive glossy sheets be able to. Glassware can take the final bulk form, such as glass fiber.

  In one embodiment, the tubing has an outer diameter (OD) size in the range of 1-500 mm and has a thickness in the range of 1-20 mm depending on the size of the tube. The length of the tubing is 24 to 60 inches for tubing having an OD of less than 100 mm, and 24 to 96 inches for tubing having an OD greater than 100 mm.

  In another embodiment, the glass preform or rod is manufactured using processes known in the art including a continuous draw process of at least two steps. In the first step, an elongated and solidified preform having an opening is stretched into a preform having a reduced diameter. The second step stretches the rod at a lower temperature than the first step, which reduces the formation of inclusions in the stretching glass rod, reducing the diameter of the preform. In one example, the OD range of the rod is 0.5 mm to 50 mm. In one embodiment, the rod is manufactured by drawing.

  In one embodiment of a continuous process, for example in the manufacture of glass plates for use in automotive applications, after the raw materials are mixed and melted, the melt is fed into a conventional float glass furnace and then fed into a mold that forms the final product.

Uniform properties of glass products :
In one embodiment, the glassware of the present invention uses at least a minimum size of 100 kg of sand in each batch for glassware made from the same lot, i.e. articles or parts made from the same mixed batch, Or it has the characteristics uniform with respect to the glass article manufactured by the continuous process of a total weight of at least 100 kg. Uniform characteristics means that the measured properties of glass pieces or products from the same lot show only small variations. The above properties include chemical properties such as OH level, viscosity, transmittance, toughness, physical properties such as color measurement, softening point, annealing point, etc .; thermal properties such as thermal expansion coefficient; compressive strength, etc. To a wide range of mechanical properties. As used herein, a plurality of products means at least 10 samples randomly selected from products / parts made from the same lot.

  The melting temperature, softening temperature, deformation temperature and annealing temperature each depend on the glass component, i.e., vary from the softening point of low lead borate glass at 600 ° C to 1650 ° C for fused silica. The glass article of the present invention has a different processing temperature depending on the amount of silica present in the composition. However, the melting temperature, softening temperature, deformation temperature and annealing temperature of glass articles made from the same lot are all characterized by little difference. In one embodiment, glass articles made from the same lot are measured on 10 or more arbitrarily selected samples of glass articles made from the same lot to determine the standard deviation of melting point, softening point, bending point, and annealing point. Each σ is less than 10 ° C. In the second embodiment, for the measurement of at least 10 arbitrarily selected samples, the variation of the standard deviation of the melting temperature, the softening temperature, the bending temperature, and the annealing temperature is each less than 5 ° C.

  In one embodiment, glass articles made from the same lot have an average annealing temperature in the range of 1000 to 1250 ° C. (corresponding to a logarithmic viscosity of 13.18 poise) and a standard deviation σ of less than 10 ° C. In 2nd Embodiment, the standard deviation (sigma) of the glass goods produced from the same lot is less than 5 degreeC.

  In one embodiment, glass articles manufactured from the same lot have a standard deviation σ of average OH concentration of 10 ppm. In one embodiment, the glass article has an average OH concentration of less than 100 ppm and a standard deviation σ of less than 10 ppm. In another embodiment, the glass is a glass article from the same batch with an average OH concentration of less than 50 ppm and a σ value of less than 5 ppm. In yet another embodiment, the average OH concentration of glass articles from the same lot is less than 30 ppm and the σ value is less than 5 ppm. In the fourth embodiment, the average OH concentration of glass products from the same lot is 20 ppm, and the σ value is less than 3 ppm.

  Glass articles made from the composition of the present invention are characterized by excellent dimensional control / stability, for example, little variation in the dimensions of finished products made from the same mold and lot. Generally, the dimensional accuracy (formability) of a glass product can be accurately determined by the stroke capability (Cpk). Here, “stroke capability” indicates the degree of quality achieved when the process is standardized and the cause of the anomaly is removed, thereby maintaining the stable conditions of the process. In one embodiment, the dimensions of the flat glass article are measured using a micrometer and caliper for at least three dimensions of the glass article length, thickness and width. In a second embodiment, the dimensions along the length (thickness) and thickness (diameter) lines are measured. In one embodiment, the glass article of the present invention is characterized in that in all three quantified dimensions, all Cpk (Process Capability Index) is greater than 1.50. In 2nd Embodiment, Cpk of the glass article produced from the same lot is more than 1.33. In yet another embodiment, the glass article was measured for outer diameter, wall thickness, and ellipticity (variation in outer diameter around the circumference), and the CpK of articles from the same lot is greater than 1.33.

In one embodiment, the glass article made from the same lot of the present invention has an average coefficient of thermal expansion from 25 ° C. to 320 ° C. of 0.54 × 10 ⁻⁶ / K to 5.5 × 10 ⁻⁷ / K. The standard deviation σ is less than 0.5 × 10 ⁻⁷ / K. In one embodiment, the glass article has an average coefficient of thermal expansion of 25 ° C. to 320 ° C. of less than 7.0 × 10 ^ −7 / K and a standard deviation σ of less than 7 × 10 ⁻⁸ / K.

  In one embodiment, a glass article made from the same lot of the present invention has a refractive index of 1.40 to 1.68 and a standard deviation of less than 0.001. In one embodiment, a glass article made from the same lot has a refractive index of 1.450 to 1.480 and a standard deviation of less than 0.0001.

  In one embodiment, a glass article of the invention consisting of 95-99.995 wt% high purity silicon dioxide produced from the same lot exhibits a visible transmission of greater than 90% in the wavelength range of 400-800 nm, with a standard deviation Is less than 2%. In a second embodiment, glass articles made from the same lot exhibit a visible transmission of greater than 90% and a standard deviation of less than 0.5% in the wavelength range 400-800 nm.

Applications and articles using glassware :
In one embodiment, the molten glass composition is molded / formed into a final product such as a glass plate or container. In another embodiment for use in lamp products, such as lamp envelopes of tungsten halogen lamp systems or lamp sleeves for tungsten halogen lamps and other high temperature lighting devices ("high intensity discharge lamps"), a molten glass composition The object is manufactured into an intermediate glass product such as a rod or tube before being formed for end use as a lamp envelope or sleeve.

  In one embodiment, the composition is used in applications where increased high contrast and visible properties of visible light transmitted or reflected may be beneficial. Such applications include, for example, the use of eyeglass glasses such as sunglasses, or a glass host for lasers. In yet another embodiment, the glass can create a computer screen with improved contrast characteristics to reduce visual discomfort or create a rearview mirror that attenuates dazzling light. The glass products with uniform properties of the present invention can also be used in applications such as ampoules, bottles, reagent containers, test tubes, titration cylinders and other medical products, chemical products, and pharmaceutical containers. In another embodiment, the product is used in applications such as automotive polish. The glass composition can also be used in bulk glass products such as fiberglass.

<< Various Examples >>
Examples are provided herein to illustrate the present invention, but these examples are not intended to limit the scope of the present invention.

The fumed silica in the examples is available from Mattson-Ridolfi as Cab-O-Sil M5 and has a BET surface area of 200 m < ² > / g and an average particle (aggregate) size of 0.2-0.3 [mu] m. The sand used is natural sand with a purity level of at least 99.99% and is available from many sources.

A glass composition is made with 96% by weight high purity silicon dioxide, 4% by weight Al ₂ O ₃ as a dopant, and other impurities maintained below 150 ppm. The Al ₂ O ₃ dopant is first coated with 0.08 wt% fumed silica before mixing into the SiO ₂ batch. This composition is then melted at 2000 ° C. in a high temperature induction electric furnace to form quartz tubes (labeled LSPG1 in later examples).

The UV blocking glass composition, high purity silicon dioxide, 96 wt%, _Al 2 _{O 3} 4% by weight, is created in titanium 200 _ppm, CeO 2 500 ppm, and other impurities that are maintained below 150 ppm. The Al ₂ O ₃ , titanium, CeO ₂ dopant mixture is first coated with 0.05 wt% fumed silica before mixing into the SiO ₂ batch. The composition is then melted at 2000 ° C. in a high temperature induction electric furnace to form quartz tubes (labeled LSPG2 in later examples).

The OH concentration (ppm) of a random sample taken from the cross section of the fused quartz tube prepared from the quartz glass composition LSPG1 of Example 1 was measured. Random samples were also collected from fused quartz glass tubes marketed by Corning, Inc., Corning, New York, as Vycor® 7907, Vycor® 7913, and Vycor® 7921. Was measured. The results of measuring the standard deviation are shown in Table 1 as follows:
Table 1

  The lamp envelope was made of fused silica tubing and Vycor® 7913 tubing made from the composition LSPG1 of Example 1 and randomly selected. No adjustments were made to the lamp production line to account for differences in the physical and chemical properties of the tubes. FIG. 2 compares a lamp made from the quartz composition of the present invention (two lamps on the right) and a lamp made from a prior art composition (two lamps on the left in the photo) and made from a prior art composition. It is the photograph which shows the deformation | transformation of two lamps.

200-400 nm UV transmission data was measured on a sample of a quartz tube made from a commercial GE214 natural quartz obtained from a) compositions LSPG1 and LSPG2 of Examples 1-2; b) GE Quartz, Ohio. did. FIG. 3 is a graph comparing UV transmission data, where the quartz glass product of the present invention made from the same batch shows a much narrower UV transmission variation band compared to the quartz glass composition of the prior art (GE214 quartz). It shows that it has.
Also, as shown in the figure, the quartz glass product of the present invention absorbs at least 90% of the 250-400 nm UV radiation and at least 87% of the 200-400 nm UV radiation. Not measured / not shown in FIG. 3, but the publicly available transmission of Vycor® 7913 compared to a narrow variation of less than 10% in the 200-300 nm range of the composition of the present invention. It is noted that the data show a significant spike from over 5% to about 90% at 200 to 300 nm.

  UV transmittance data from 200 nm to 800 nm was measured for samples of quartz tubing made from the composition LSPG2 of Example 2 and commercial products including Osram 406, Philips 521 and Vycor® 7907. FIG. 4 is a graph comparing the UV transmission data of various samples. As can be seen, the transmission data of the inventive sample shows little variation in the 200-300 nm range compared to the prior art samples.

  OH concentrations were measured for samples of quartz tubes made from the composition LSPG2 of Example 2 and commercial products including Osram 406, Philips 521, Vycor® 7907 and Philips low viscosity glass. FIG. 5 is a graph comparing OH concentrations in ppm for Example 2 of the present composition versus various prior art glass samples (commercially available glasses shown as reference samples 1-5). As shown in the figure, the inventive sample has a much lower average OH level and standard deviation compared to the prior art samples.

4 × 4 × 1 inch (thick) size glass pack for comparison: 1) 96% by weight high purity silicon dioxide, 4% by weight Al ₂ O ₃ as dopant, other impurities maintained below 150 ppm Glass component; and 2) Dissolved and prepared from LSPG1 composition of the present invention, Example 1 and a composition of 0.08 wt% fumed silica. FIG. 6 is a photograph comparing two glass packs with a comparative glass pack on the left side and an LSPG1 glass pack on the right side. As the photo shows, the right glass has greater clarity (or transparency through the glass) compared to the left glass, and the letters directly under the LSPG1 pack on the right appear / easier I can read it.
This specification discloses the invention using examples, including the best mode, and also allows any person skilled in the art to make and use the invention.

It is the graph which showed the viscosity change of high purity quartz glass as a function of OH concentration. A photograph comparing a lamp envelope made with a glass composition in one embodiment of the present invention, ie, two wire lamps on the right side and two lamp envelopes made with a glass composition of the prior art (left side lamp). It is. FIG. 5 is a graph comparing the variation in UV transmission data for a sample from a glass product of the present invention made from the same lot and a sample from a glass product made from a prior art composition. FIG. 4 is a graph comparing the variation in UV transmission data in the range of 200-800 nm between a sample from a glass product of the present invention made from the same lot and a sample from a commercially available prior art glass product. 2 is a graph comparing the mean OH concentration and standard deviation of a reference sample from one embodiment of the glass composition of the present invention and a commercially available prior art glass product. In particular, regarding clarity (or glass transmittance), it is a photograph comparing a glass “pack” made from a glass composition in one embodiment of the present invention with a glass pack made from a glass composition in the prior art.

Claims (8)

In a glass composition containing a lot of glassware,
The SiO ₂ 40 to 99 _{wt%, Al 2 O 3, CeO} 2, TiO 2, Nd 2 O 3, B 2 O 3, CeO 2, BaO, SrO, CaO, MgO, Na 2 O, K 2 O, Li 0.1 to 25 wt% of at least one dopant selected from the group of metal oxides of ₂ O, Sb ₂ O ₃ , and mixtures thereof; and a BET of 50 to 400 m ² / g and an average particle size of less than 1 μm A composition containing 0.02 to 0.50 wt% of a fumed metal oxide, wherein the fumed metal oxide is SiO ₂ or a metal oxide present in a dopant . The glass composition of claim 1 ,
The SiO ₂ containing 90 to 95 wt%, random sample of the selected 10 or more glass article when annealed temperature measured in said lot, annealing temperature is in the range of 1000 to 1250 ° C. Glass composition. In the glass composition in any one of Claims 1 thru | or 2 ,
When measuring the OH concentration from a sample of the 10 or more glass articles randomly selected in the lot, OH @ - concentration glass compositions which are less than 100 ppm. In the glass composition in any one of Claims 1 thru | or 3 ,
Randomly when measuring OH concentration from a sample of the selected 10 or more glass articles in the lot, glass compositions OH concentration is less than 30 ppm. In the glass composition in any one of Claims 1 thru | or 4 ,
A glass composition in which a glass product is processed based on a process standardized to a process capability of CpK 1.33 or more. In any of the glass composition of claims 1 to _{5, Al 2 O 3, CeO} 2, TiO 2, Nd 2 O 3, B 2 O 3, CeO 2, BaO, SrO, CaO, MgO, Na 2 O, 0.1 to 25 wt% of at least one dopant selected from the group of metal oxides of K ₂ O, Li ₂ O, Sb ₂ O ₃ , and mixtures thereof; and BET is 50 to 400 m ² / g, average A composition containing 0.05 to 0.15% by weight of a fumed metal oxide having a particle size of less than 1 μm, the fumed metal oxide being SiO ₂ or a metal oxide present in a dopant, the metal oxides are first mixed at least one of 20-100% dopant to form a master batch, then the glass composition is added this to SiO ₂ of the glass composition In a manufacturing method for producing a glass product with reduced variation in characteristics,
The SiO ₂ 40 to 99 wt%, and _{Al 2 O 3, CeO 2,} Nd 2 O 3, B 2 O 3, CeO 2, TiO 2, BaO, SrO, CaO, MgO, Na 2 O, K 2 O, Supplying 0.1 to 25% by weight of at least one dopant selected from the group of metal oxides of Li ₂ O, Sb ₂ O ₃ , and mixtures thereof;
However, the dispersant is a fumed metal oxide having a BET of 50 to 400 m ² / g and an average particle size of less than 1 μm, and the fumed metal oxide is SiO ₂ or a metal oxide present in the dopant. Then forming a first blend of 0.02 to 0.50 weight percent dispersant and 20% to 100% at least one dopant;
Blending the first blend with SiO ₂ and some balance of at least one dopant forming a mixture;
Producing a molten glass melt from the mixture;
Consisting of a step of passing molten glass along a tool to form a glass product,
Quartz products are in the form of tubes, rods, blanks, and strands, with weight percent being a manufacturing method that produces glass products based on the total weight of the final mixture. In quartz glass product, the SiO ₂ 40 to 99 _{wt%, Al 2 O 3, CeO} 2, Nd 2 O 3, B 2 O 3, CeO 2, BaO, TiO 2, SrO, CaO, MgO, Na 2 O, 0.1 to 25 wt% of at least one dopant selected from the group of metal oxides of K ₂ O, Li ₂ O, Sb ₂ O ₃ , and mixtures thereof; and BET is 50 to 400 m ² / g, average A quartz glass product comprising 0.04 to 0.30% by weight of fumed metal oxide having a particle size of less than 1 μm, wherein the fumed metal oxide is SiO ₂ or a metal oxide present in the dopant; 40 to 99 prior to blending with some of the remainder of the weight percent of SiO ₂ and at least one dopant, the fumed metal oxide, small to form a master batch First blends quartz glass products and Kutomo 20-100% one dopant.