WO2014062715A1

WO2014062715A1 - High modulus glass fibers

Info

Publication number: WO2014062715A1
Application number: PCT/US2013/065105
Authority: WO
Inventors: Robert HAUSRATH; Anthony Longobardo; Brian RUPPEL
Original assignee: Agy Holding Corporation
Priority date: 2012-10-16
Filing date: 2013-10-15
Publication date: 2014-04-24

Abstract

Glass compositions and high-modulus and high-strength glass fibers made therefrom, being capable of continuous processing and suitable for production of high-strength and/or high stiffness articles are disclosed. The glass composition may include the following constituents: between about 45 to about 65 weight percent SiO₂; between about 12 to about 27 weight percent Al₂O₃, wherein the weight percent ratio of SiO₂/Al₂O₃ is between about 2 to about 4; between about 5 to about 15 weight percent MgO; between about 2 to about 10 weight percent CaO, wherein the weight percent ratio of MgO/CaO is between about 1 to about 4; between about 0 to about 1 weight percent Na₂O; between about 0.01 to about 14.5 weight percent Y₂O₃; between about 0 to about 3 weight percent TiO₂; and between about 0 to about 5 weight percent ZrO₂.

Description

TITLE

HIGH MODULUS GLASS FIBERS

BACKGROUND

[0001] The present disclosure is generally directed to glass compositions, suitable for use in continuous manufacturing of high strength, high modulus, glass fibers, and specifically, fibers formed from the composition and composites thereof.

[0002] Glass fibers have various properties including stiffness, as measured by determining a Young's modulus of elasticity value. The higher the Young's modulus value, the stiffer the glass fibers. Young's modulus is a ratio of tensile stress to strain and is measured directly using standard tests. The Young's modulus of elasticity of unannealed silicate glass fibers, for example, typically ranges from about 52 GPa (gigaPascal) to 87 GPa. As glass fiber is heated, the modulus gradually increases. E-glass fibers that have been annealed to compact their atomic structure will experience an increase in modulus from 72 GPa to 84.7 GPa. A high strength glass fiber, such as S-2 Glass®, which is a composition of magnesium aluminosilicate, when annealed, typically has a Young's modulus of 94 GPa measured at 20°C. Various types of glass fibers are described more completely in industry standards such as ASTM C 162.

[0003] The present invention discloses a glass fiber composition with the ability to be fiberized continuously and typically resulting in a fiber with a Young's Modulus value equal to or greater than traditional S-2 glass.

SUMMARY

[0004] Glass compositions for the formation of glass fibers that are suitable for use in high-strength applications and articles and that are capable of being economically formed through continuous fiberization into glass fibers are provided. The glass fibers formed from the instant glass compositions are typically high- strength and exhibit a Young's Modulus in excess of 90 GPa.

[0005] Thus, in one embodiment, a glass composition including between about 45 to about 65 weight percent Si0₂; between about 12 to about 27 weight percent Al₂0₃, wherein the weight percent ratio of Si0₂/Al₂0₃ is between about 2 to about 4; between about 5 to about 15 weight percent MgO; between about 2 to about 10 weight percent CaO, wherein the weight percent ratio of MgO/CaO is between about 1 to about 4; between about 0 to about 1 weight percent Na₂0; between about 0.01 to about 14.5 weight percent Y₂0₃; between about 0 to about 3 weight percent Ti0₂; and between about 0 to about 5 weight percent Zr0_2i is provided. Glass fibers formed from the composition are also provided.

[0006] In another embodiment, the glass composition comprises between about 49 to about 64 weight percent Si0₂; between about 17 to about 23 weight percent Al₂0₃, wherein the weight percent ratio of Si0₂/Al₂0₃ is between about 2.4 to about 3.5; between about 6 to about 14 weight percent MgO; between about 3 to about 8 weight percent CaO, wherein the weight percent ratio of MgO/CaO is between about 1.1 to about 4.0; between about 0 to about 1 weight percent Na₂0; between about 4 to about 13 weight percent Y₂0₃; between about 0 to about 3 weight percent Ti0₂; and between about 0.01 to about 5 weight percent Zr0₂. Glass fibers formed from the composition are also provided.

[0007] In yet another embodiment, a process for providing continuous, manufacturable, high modulus glass fibers is provided. The process includes the steps of providing a composition into a melting zone of a glass melter, the composition comprising: between about 45 to about 65 weight percent Si0₂; between about 12 to about 27 weight percent Al₂0₃, wherein the weight percent ratio of Si0₂/Al₂0₃ is between about 2 to about 4; between about 5 to about 15 weight percent MgO; between about 2 to about 10 weight percent CaO, wherein the weight percent ratio of MgO/CaO is between about 1 to about 4; between about 0 to about 1 weight percent Na₂0; between about 0.01 to about 14.5 weight percent Y₂0₃; between about 0 to about 3 weight percent Ti0₂; and between about 0 to about 5 weight percent Zr0₂; heating the glass to form a fiberizable molten glass; and continuously fiberizing said molten glass whereby a manufacturable high modulus glass fiberization process is sustained.

[0008] In another embodiment, a fiberglass reinforced article is provided. The article comprises glass fibers of the composition described above and a matrix material.

DETAILED DESCRIPTION OF EMBODIMENTS OF THE INVENTION

[0009] The present invention is a class of glass fibers having a composition that yields high values of Young's modulus of elasticity. Typically, the glass fibers of the present invention yield a higher value of Young's modulus than that of existing S-glass. Such increases in the Young's modulus of the present composition enhance the mechanical properties and effectiveness of the glass fibers thereby increasing the usability and effectiveness of the glass fibers over a wide range of products, especially when the fibers are combined in a fabric.

[0010] The composition of the present invention is generally composed of an S-glass or R-glass type combination, which may have one or more of the following oxides including yttrium oxide, zirconium oxide, titanium oxide, or small fractions of other rare earth oxides. The S-glass or R-glass type combination of the present invention may be an S-1 glass, which is a hybrid of S-glass and R-glass. S-1 glass is beneficial because of the large difference between its log 3 viscosity and liquidus temperature. The composition of the present invention typically yields an annealed Young's modulus in excess of 95 GPa. Further, the composition of the present glass has the ability to fiberize continuously because of its positive difference between the log 3 viscosity and liquidus temperature (ΔΤ₃).

[0011] Unless otherwise stated, the following terms used in the specification and claims have the meanings given below.

[0012] As used herein unless otherwise stated, the term "modulus" refers to Young's Modulus.

[0013] As used herein, the term "liquidus" is given its ordinary and customary meaning, generally inclusive of the highest temperature at which equilibrium exists between liquid glass and its primary crystalline phase, whereas at all temperatures above the liquidus, the glass melt is free from crystals in its primary phase and at temperatures below the liquidus, crystals may form in the melt.

[0014] As used herein, the term "delta-T (ΔΤ)" is given its ordinary and customary meaning, generally inclusive of the difference between the fiberizing temperature and the liquidus, and thus, a fiberizing property of the glass composition. The larger the delta-T, the more process flexibility exists during the formation of glass fibers and the less likely de-vitrification (crystallization) of the glass melt will occur during melting and fiberizing. Typically, the greater the delta-T, the lower the production cost of the glass fibers, in part by extending bushing life and by providing a wider fiber-forming process window.

[0015] By "fiber" is meant an elongate body, the length dimension of which is much greater than the transverse dimensions of width and thickness. Accordingly, the term fiber includes monofilament, multifilament, ribbon, strip, staple and other forms of chopped, cut or discontinuous fiber and the like having regular or irregular cross-sections. Fiber and filament are used interchangeably herein. Accordingly, the phrases "finer diameter glass fiber" and "finer filament diameter glass fiber" are also used interchangeably herein.

[0016] By "network" is meant fibers arranged in configurations of various types. For example the plurality of fibers can be grouped together to form a twisted or untwisted yarn. The fibers of yarn may be formed as a felt, knitted or woven (plain, basket, stain and crow feet weaves, etc.) into a network, fabricated into a non-woven fabric (random or ordered orientation), arranged in a parallel array, layered, or formed into a fabric by any of a variety of conventional techniques.

[0017] The terms "S-glass" and "E-glass" are used according to their meaning as described in ASTM D-578. For example, S-glass fibers are generally comprised of the oxides of magnesium, aluminum, and silicon. S-glass fibers may further include trace amounts of alkali metal oxides and iron oxides. E-glass fibers are generally comprised of the oxides of calcium, aluminum, and silicon.

[0018] The term "R-glass" is used to describe glass compositions generally comprised of the oxides of calcium, magnesium, aluminum, silicon, and trace amounts of boron oxides, iron oxides, and fluorine.

[0019] By "high strength" is meant a glass fiber having higher tensile strength and higher tensile modulus than E-glass fiber. Generally, high strength, finer diameter glass fibers disclosed herein may be S-glass fibers. Accordingly, the phrases "high strength glass fiber" and "high strength S-glass fiber" and "S-glass fiber" all have the same meaning when used herein. By way of example, high strength, finer diameter S-glass fibers have a pristine fiber tensile strength of greater than 3450 MPa, more preferably a pristine fiber tensile strength of greater than 4137 MPa, and most preferably a pristine fiber tensile strength of greater than 4585 MPa.

[0020] High strength, finer diameter glass fiber further includes compositions having a composition that deviates from the S-glass composition described above. Accordingly, use of the phrase "high strength glass fiber" is meant to encompass high strength glass fibers having compositions that deviate from S- glass compositions described above, with the proviso that the composition is other than that of E-glass.

[0021] The glass fiber of the present invention typically includes a composition having between 45 and 65 percent silicon dioxide (Si0₂). When the silicon dioxide percentage is outside of this range, the viscosity and fiberization of the glass is typically affected. For example, the viscosity of the glass may decrease to the extent that devitrification (crystallization) during fiberization results when silicon dioxide is less than 45 percent of the total composition of the glass fiber. In contrast, when silicon dioxide is greater than 65 percent of the total composition of the glass fiber, the glass may become too viscous thereby making it more difficult to melt and fiberize. Thus, the silica content is preferably between 45 and 65 percent of the total composition of the glass. Further, to yield the highest Young's Modulus value, the silica content is more preferably between 49 and 59 percent of the total composition of the glass. Even more preferably, the silica content is between 49 and 54 percent of the total composition of the glass.

[0022] The glass fiber of the present invention typically also includes a composition having between 12 and 27 percent aluminum oxide (Al₂0₃). The percentage of aluminum oxide with respect to the total composition of the glass fiber may also affect the viscosity and fiberization process. For example, a high percentage of aluminum oxide, such as above 27 percent, may cause the melt viscosity to decrease so that devitrification during fiberization results. Thus, the alumina content is preferably between 12 and 27 percent of the total composition of the glass. Further, to yield the highest Young's Modulus value, the alumina content is more preferably between 17 and 23 percent of the total composition of the glass. Even more preferably, the alumina content is between 19 and 22 percent of the total composition of the glass.

[0023] The silicon dioxide and aluminum oxide weight ratio significantly influences the Young's modulus value of the glass fibers. Advantageously, the weight ratio of silicon dioxide to aluminum oxide is between about 2 to about 4. More advantageously, the weight ratio of silicon dioxide to aluminum oxide is between about 2.4 to about 3.5. Even more advantageously, the weight ratio of silicon dioxide to aluminum oxide is between about 2.45 and 2.81. A weight ratio of silicon dioxide to aluminum oxide in this range allows for achievement of high modulus fibers.

[0024] The glass fiber composition of the present invention also includes magnesium oxide (MgO) and calcium oxide (CaO). Preferably, the glass fiber composition is between 5 and 15 percent magnesium oxide and between 2 and 10 percent calcium oxide. More preferably, the magnesia content is between 6 and 14 percent and the calcium oxide content is between 3 and 8. The weight percent of both magnesium oxide and calcium oxide typically impacts the viscosity and devitrification process of the glass fiber.

[0025] The magnesium oxide and calcium oxide weight ratio influences the Young's modulus and liquidus temperature of the glass. Advantageously, the weight ratio of magnesium oxide to calcium oxide is between about 1 to about 4. More advantageously, the weight ratio of magnesium oxide to calcium oxide is between about 1.1 and about 4.0. Even more advantageously, the weight ratio of magnesium oxide to calcium oxide is between about 1.33 and about 3.96. A weight ratio of magnesium oxide to calcium oxide in this range allows for achievement of high modulus fibers.

[0026] The glass fiber of the present invention typically also includes a composition having between 0.01 and 14.5 percent yttrium oxide (Y2O3). The percentage of yttrium oxide with respect to the total composition of the glass fiber significantly affects Young's Modulus. A high Young's Modulus may be achieved through the addition of between about 4 and 13 percent yttrium oxide. An even higher Young's Modulus is typically achieved when the yttrium oxide content is between approximately 8 and 13 weight percent of the total composition of the glass.

[0027] The addition of zirconium oxide (Zr0₂) may also increase the Young's Modulus and stiffness of the glass fibers. Thus, the zirconia content is preferably between 0.01 and 5 percent of the total composition of the glass. Further, to yield higher Young's Modulus values, the zirconia content is more preferably between 0.49 and 4.3 percent of the total composition of the glass.

[0028] Sodium oxide (Na₂0) may be added to the glass composition herein disclosed in order to limit devitrification and reduce the viscosity of the glass. Preferably, the weight percent of sodium oxide is between 0 and about 1 percent. More preferably, the weight percent of sodium oxide is between about 0 and 0.5.

[0029] Titanium oxide (Ti0₂) may be present in the glass composition and typically acts as a viscosity reducer. It may be present as an impurity from conventional raw material or it may be intentionally added. Preferably, the titanium oxide content is between 0 to 3 weight percent. More preferably, the titanium oxide content is between 0.02 and 2.31 weight percent.

[0030] Boron oxide (B₂0₃) may be present in the instant glass composition but is not a necessary oxide to the composition. Frequently, the existence of boron oxide in the glass composition is due to raw material impurities and therefore boron oxide is not intentionally added. Preferably the weight percent of boron oxide, if present in the glass composition, is less than 1 and more preferably approximately 0 to 0.01.

[0031] Iron oxide (Fe₂0₃) and Manganese oxide (MnO) may be present in the instant glass composition but are also not necessary additions. Preferably the weight percent of iron oxide, if present in the glass composition, is less than 1 and more preferably approximately 0.09 to 0.16. Further, preferably the weight percent of manganese oxide, if present in the glass composition, is also less than 1 and more preferably approximately 0.01 to 0.03.

[0032] As discussed above, the composition of the glass for providing high modulus fibers is, at least in part, based on the weight percent of the oxides discussed above as well as the ratios of silicon dioxide to aluminum oxide and magnesium oxide to calcium oxide. In one aspect, the combination of these parameters makes it possible to obtain high Young modulus values of greater than 90 GPa. In certain aspects, the combination of these parameters makes it possible to obtain Young modulus values between 91.6 GPa and 105.8 GPa.

[0033] In addition to the above parameters, the combination of the weight percent of two constituents of the present glass composition is significant. In particular, the weight percent combination of silicon dioxide and aluminum oxide is preferably between 66 and 85. More preferably, the weight percent combination of silicon dioxide and aluminum oxide is between 69 and 82. Even more preferably, the weight percent combination of silicon dioxide and aluminum oxide is between 69 and 74. Further, the weight percent combination of magnesium oxide and calcium oxide is preferably between 10 and 20. More preferably, the weight percent combination of magnesium oxide and calcium oxide is between 12 and 18.

[0034] Other metal oxides, for example BaO, SrO, ZnO, K₂0, Li₂0, La₂0_3, and V₂0₃ may be present in the glass composition. The addition of these oxides is typically as trace impurities, that is, they are not intentionally added. Thus, the total combined weight percent of BaO, SrO, and ZnO is preferably less than 2. The combined weight percent of Li₂0 and K₂0, as well as taking into account the weight percent of Na₂0, is preferably less than 1. The combined weight percent of La₂0₃ and V₂0₃ is preferably less than 2. Having increased amounts of these metal oxides may increase the density and result in lowering the specific Young's modulus. Thus, the composition preferably contains essentially no BaO, SrO, ZnO, K₂0, Li₂0, La₂0_3, or V₂03.

[0035] In one aspect, the glass is essentially free of any additional components other than silicon dioxide, aluminum oxide, magnesium oxide, calcium oxide, and yttrium oxide. In another aspect, the glass is essentially free of any additional components other than silicon dioxide, aluminum oxide, magnesium oxide, calcium oxide, yttrium oxide and zirconium oxide. In still another aspect, the glass is essentially free of any additional components other than silicon dioxide, aluminum oxide, magnesium oxide, calcium oxide, sodium oxide, yttrium oxide, titanium oxide, and zirconium oxide. In yet another aspect, the glass is essentially free of any additional components other than silicon dioxide, aluminum oxide, magnesium oxide, calcium oxide, sodium oxide, yttrium oxide, iron oxide, titanium oxide, manganese oxide, boron oxide, and zirconium oxide. In these examples, "essentially free" means that any other material present is preferably in an amount that would not materially affect the novel characteristics of the instant composition, such as its manufacturability and high strength and modulus.

Manufacturing

[0036] The disclosed and described processes relate to glass fibers, which can be obtained by mechanically attenuating streams of molten glass that flow out of orifices located in the base of a bushing, which is heated by resistance heating or other means. These glass fibers may be intended especially for the production of meshes and fabrics used in composites having an organic and/or inorganic matrix.

[0037] The glasses disclosed and described herein may be suitable for melting in traditional commercially available refractory-lined glass melters made from appropriate refractory materials such as alumina, chromic oxide, silica, alumina- silica, zircon, zirconia-alumina-silica, or similar oxide based refractory materials that are widely used in the manufacture of glass reinforcement fibers, in what is commonly called a direct-melt process. Often, such glass melting furnaces include one or more bubblers and/or electrical boost electrodes. The bubblers and/or electrical boost electrodes increase the temperature of the bulk glass and increase the molten glass circulation under the batch cover. Alternatively, noble metals or alloys of noble metals may also be used to line said melting containers. In addition, Noble metals or alloys of noble metals may be used to power said melting containers. [0038] In one aspect, the melted glass composition disclosed herein is delivered to a bushing assembly from a forehearth. The bushing may include a tip plate with a plurality of nozzles, each nozzle discharging a stream of molten glass, which is mechanically drawn to form a continuous filament. Glass fibers according to the instant disclosure may be obtainable from the glasses of the composition described as above to provide a large number of streams of molten glass flowing out of a large number of orifices located in the base of one or more bushings that are attenuated into the form of one or more groups of continuous filaments, which are combined into fibers and collected on a moving support. This support may rotate, so as to collect the fibers in the form of wound packages, or may translate, such as when the fibers are to be chopped or sprayed by a device that also serves to draw them, so as to form a mat.

[0039] Having generally described this instant disclosure, a further understanding can be obtained by reference to certain specific examples illustrated below which are provided for purposes of illustration only and are not intended to be all inclusive or limiting unless otherwise specified.

Examples

[0040] The exemplary glasses listed in Tables 1 , 2, and 3 were prepared by melting in platinum crucibles or in a refractory melter. Mechanical and physical properties of the glass and fibers produced were measured for representative glass samples. The units of measurement for the physical properties are: liquidus temperature (°C), density (g/cm³), and Young's Modulus, E, (GPa). The specific modulus was also calculated and is the ratio of stiffness to weight.

[0041] Liquidus temperature was measured by placing a platinum container filled with glass in a thermal gradient furnace for about 24 hours. The greatest temperature at which crystals were present was considered the liquidus temperature denoted by T|jq_Uidus- Young's modulus was measured using a sonic technique on an annealed bulk glass sample. Tensile strength was measured on a pristine single fiber.

[0042] Fiberizing temperature were also measured using a rotating spindle viscometer at various fiberizing viscosities including T₃ (1000 Poise).

[0043] The following examples illustrate the exemplary fibers without limitation. [0044] Glass fibers made up of glass filaments of about 10 micron in diameter were obtained by attenuating molten glass having the compositions given in Tables 1 , 2, and 3. The compositions are expressed in percentages by weight or ratios of percent by weight.

TABLE 1

TABLE 2

TABLE 3

[0045] The properties of the glass fibers formed using the disclosed compositions have superior and/or comparable mechanical properties, including modulus and strength characteristics, to that of other known glass fiber compositions. Moreover the compositions allow for continuous fiberization.

[0046] Particularly, the glass fibers of the compositions disclosed in examples 1 through 10 shown in Table 1 revealed a Young's Modulus between 91.6 GPa and 97.3 GPa. The liquidus temperatures measured were less than 1267 °C. Of note, the combined weight percentage of silicon dioxide and aluminum oxide was between 76.91 and 81.97. The weight percentage range of silicon dioxide was between 54.67 and 63.70, the weight percentage range of magnesium oxide was 6.69 to 9.39, and the weight percentage range of yttrium oxide was 4.75 to 5.00. Zirconium oxide was not present in the glass fiber compositions disclosed in Table 1.

[0047] The glass fibers of the compositions disclosed in examples 1 1 through 20 shown in Table 2 generally revealed a higher Young's Modulus than those disclosed in Table 1 and were between 96.8 GPa and 104.1 GPa. The liquidus temperatures measured were between 1205 °C and 1301 °C. Of note, the combined weight percentage of silicon dioxide and aluminum oxide was between 72.01 and 74.97. The weight percentage range of silicon dioxide was between 52.01 and 56.71 , the weight percentage range of magnesium oxide was 9.38 to 13.66, and the weight percentage range of yttrium oxide was 6.94 to 9.76. The weight percentage range of zirconium oxide was between 0 and 2.00.

[0048] The glass fibers of the compositions disclosed in examples 21 through 30 shown in Table 3 generally revealed a similar or even higher Young's Modulus than those disclosed in Table 2 and were between 103.6 GPa and 105.8 GPa. The liquidus temperatures ranged from 1266 °C to greater than 1357 °C. Of note, the combined weight percentage of silicon dioxide and aluminum oxide was between 69.84 and 72.1 1. The weight percentage range of silicon dioxide was between 49.99 and 52.25, the weight percentage range of magnesium oxide was 7.92 to 10.81 , and the weight percentage range of yttrium oxide was 9.45 to 12.83. The weight percentage range of zirconium oxide was between 2.50 and 4.30.

[0049] As apparent from the above examples and when utilizing the above constituents in the glass composition, incorporating and increasing the weight percent of yttrium oxide may have a positive effect on strength and elasticity of glass fibers by increasing the Young's Modulus. Reducing the weight percent of silicon dioxide, lowering the combined weight percentage of silicon dioxide and aluminum oxide, slightly increasing the weight percent of magnesium oxide, and/or including a zirconium oxide constituent, may also have a positive effect on increasing the Young's Modulus when using the above disclosed constituents in a glass composition. Other advantages and obvious modifications of the instant disclosure will be apparent to the artisan from the above description and further through practice of the instant disclosure. The high-performance and strength glass disclosed and described herein melts and refines at temperature ranges that are easily workable and allow for continuous fiberization of the glass composition. [0050] The above exemplary inventive compositions do not always total 100% of the listed components due to statistical conventions (such as, rounding and averaging) and the fact that some compositions may include impurities that are not listed. Of course, the actual amounts of all components, including any impurities, in a composition always total 100%. Furthermore, it should be understood that where small quantities of components are specified in the compositions, for example, quantities on the order of about 1 weight percent or less, those components may be present in the form of trace impurities present in the raw materials, rather than intentionally added.

[0051] Additionally, components may be added to the batch composition, for example, to facilitate processing, that are later eliminated, thereby forming a glass composition that is essentially free of such components. Thus, for instance, minute quantities of components such as fluorine and sulfate may be present as trace impurities in the raw materials providing the silica, calcia, alumina, and magnesia components in commercial practice of the instant disclosure or they may be processing aids that are essentially removed during manufacture.

Applicability

[0052] The glass fibers formed from the above described compositions may be particularly suitable for use in compounded thermoplastic matrix products used where structural reinforcements are required. Further, the glass fibers may be formed into a composite. For example the glass fibers may be combined with a curable matrix material. In one aspect, the composite is configured for applications where high strength and stiffness and low weight are desired and/or required. Applications suitable for such a composite incorporating the glass fibers as described above in combination with an organic, inorganic, or organic-inorganic matrix material, include, for example, civilian and military transportation (e.g., aerospace vehicles, military combat and tactical vehicles, civilian personal and public transportation vehicles, etc.), wind energy (such as wind turbine blades), reinforcements for the construction industry (cement boards, window screening, etc.), and the like. In other aspects, the glass fibers as described above in combination with an organic, inorganic, or organic-inorganic matrix material are applicable for any application where a light weight, stiff and high strength composite article is desired. [0053] Suitable curable matrix materials may include thermoset and thermoplastic resins. By way of example, suitable organic, inorganic, or organic- inorganic matrix materials include cements, ceramics, natural and synthetic rubbers, vinyl esters, polyesters, epoxy resin, polyurethanes, acrylic resins, and combinations or copolymers thereof. The organic matrix can be a thermoplastic or a thermoset material. Composite articles comprising the instant invention can be manufactured using any suitable composite fabrication technique, for example vacuum-assisted resin infusion or pre-impregnated reinforcement lay-up, resin transfer molding, compression molding, pultrusion, chopped fiber infused thermoplastic compounding, etc.

[0054] In one aspect of the instant disclosure, after the glass filaments are pulled and attenuated, sizing is applied, using conventional techniques. After the sizing is applied, the resulting fibers are collected into a roving, which is then wound into a package, e.g., using a conventional winder. In one aspect, the sizing composition is particularly suited for the high-temperature glass fibers, providing protection from abrasion during processing and to help facilitate the wetting of the coated fibers by a liquid material which will cure or set to form a solid resinous matrix in which the fibers are embedded as reinforcing elements, preferably enhancing the coupling between the cured resinous matrix and the glass fibers.

[0055] As required, detailed embodiments of the present invention are disclosed herein; however, it is to be understood that the disclosed embodiments are merely exemplary of the invention that may be embodied in various and alternative forms. Therefore, specific structural and functional details disclosed herein are not to be interpreted as limiting, but merely as a basis for the claims and as a representative basis for teaching one skilled in the art to variously employ the present invention. It will be apparent to those skilled in the art that many changes and substitutions may be made to the foregoing description of preferred embodiments and examples without departing from the spirit and scope of the present invention, which is defined by the appended claims.

[0056] While various embodiments and examples of this invention have been described above, these descriptions are given for purposes of illustration and explanation. Variations, changes, modifications, and departures from the systems and methods disclosed above may be adopted without departure from the spirit and scope of this invention.

Claims

WHAT IS CLAIMED IS:

1. A glass composition comprising:

between about 45 to about 65 weight percent Si0₂;

between about 12 to about 27 weight percent Al₂0₃, wherein the weight percent ratio of Si0₂/Al₂0₃ is between about 2 to about 4;

between about 5 to about 15 weight percent MgO;

between about 2 to about 10 weight percent CaO, wherein the weight percent ratio of MgO/CaO is between about 1 to about 4;

between about 0 to about 1 weight percent Na₂0;

between about 0.01 to about 14.5 weight percent Y₂0₃;

between about 0 to about 3 weight percent Ti0₂; and

between about 0 to about 5 weight percent Zr0₂.

2. The glass composition of claim 1 , wherein the weight percent Si0₂ is between about 49 to about 64.

3. The glass composition of claim 1 , wherein the weight percent Al₂0₃ is between about 17 to about 23.

4. The glass composition of claim 1 , wherein the weight percent MgO is between about 6 to about 14.

5. The glass composition of claim 1 , wherein the weight percent CaO is between about 3 to about 8.

6. The glass composition of claim 1 , wherein the weight percent Y₂0₃ is between about 4 to about 13.

7. The glass composition of claim 1 , wherein the weight percent ratio of Si0₂/Al₂0₃ is between about 2.4 to about 3.5.

8. The glass composition of claim 1 , wherein the weight percent ratio of

MgO/CaO is between about 1.1 to about 4.0.

9. The glass composition of claim 1 , wherein the combined weight percent Si0₂ and Al₂0₃ is between about 66 to about 85.

10. The glass composition of claim 1 , wherein the combined weight percent CaO and MgO is between about 10 to about 20.

1 1 . The glass composition of claim 1 , wherein the combined weight percent Li₂0, Na₂0, and K₂0 is less than about 1.

12. The glass composition of claim 1 , wherein the combined weight percent SrO, BaO, and ZnO is less than about 2.

13. The glass composition of claim 1 , wherein the combined weight percent La₂0₃ and V₂0₃ is less than about 2.

14. The glass composition of claim 1 , consisting essentially of:

between about 49 to about 64 weight percent Si0₂;

between about 17 to about 23 weight percent Al₂0₃, wherein the weight percent ratio of Si0₂/Al₂0₃ is between about 2.4 to about 3.5;

between about 6 to about 14 weight percent MgO;

between about 3 to about 8 weight percent CaO, wherein the weight percent ratio of MgO/CaO is between about 1.1 to about 4.0;

between about 0 to about 1 weight percent Na₂0;

between about 4 to about 13 weight percent Y₂0₃;

between about 0 to about 3 weight percent Ti0₂; and

between about 0.01 to about 5 weight percent Zr0₂.

15. The glass composition of claim 1 , wherein the composition has a fiberizing temperature of greater than about 1250° C.

16. A glass fiber comprising:

between about 45 to about 65 weight percent Si0₂;

between about 5 to about 15 weight percent MgO;

between about 0 to about 1 weight percent Na₂0;

between about 0.01 to about 14.5 weight percent Y₂0₃;

between about 0 to about 3 weight percent Ti0₂; and

between about 0 to about 5 weight percent Zr0₂.

17. The glass fiber of claim 16, wherein the glass fiber has a Young's Modulus of at least 90 GPa.

18. The glass fiber of claim 16, wherein the glass fiber has a Young's

Modulus of at least 95 GPa.

19. The glass fiber of claim 16, comprising:

between about 49 to about 64 weight percent Si0₂;

between about 6 to about 14 weight percent MgO;

between about 0 to about 1 weight percent Na₂0;

between about 4 to about 13 weight percent Y₂0₃;

between about 0 to about 3 weight percent Ti0₂; and

between about 0.01 to about 5 weight percent Zr0₂.

20. The glass fiber of claim 16, consisting essentially of:

between about 49 to about 64 weight percent Si0₂;

between about 17 to about 23 weight percent Al₂0₃, wherein the weight percent ratio of Si0₂/AI₂0₃ is between about 2.4 to about 3.5;

between about 6 to about 14 weight percent MgO;

between about 0 to about 1 weight percent Na₂0;

between about 4 to about 13 weight percent Y₂0₃;

between about 0 to about 3 weight percent Ti0₂; and

between about 0.01 to about 5 weight percent Zr0₂.

21. The glass fiber of claim 16, wherein the combined weight percent Si0₂ and Al₂0₃ is between about 66 to about 85.

22. The glass fiber of claim 16, wherein the combined weight percent CaO and MgO is between about 10 to about 20.

23. The glass fiber of claim 16, wherein the combined weight percent Li₂0, Na₂0, and K₂0 is less than about 1.

24. The glass fiber of claim 16, wherein the combined weight percent SrO, BaO, and ZnO is less than about 2.

25. The glass fiber of claim 16, wherein the combined weight percent La₂0₃ and V₂0₃ is less than about 2.

26. A process for providing continuous, manufacturable, high modulus glass fibers, the process comprising the steps of:

providing a composition to a melting zone of a glass melter, the composition comprising:

between about 45 to about 65 weight percent Si0₂; between about 12 to about 27 weight percent Al₂0₃, wherein the weight percent ratio of Si0₂/Al₂0₃ is between about 2 to about 4;

between about 5 to about 15 weight percent MgO;

between about 0 to about 1 weight percent Na₂0;

between about 0.01 to about 14.5 weight percent Y₂0₃;

between about 0 to about 3 weight percent Ti0₂; and

between about 0 to about 5 weight percent Zr0₂;

heating the composition to a forming temperature in excess of the liquidus temperature of a resulting glass to form a fiberizable molten glass; and

continuously fiberizing said molten glass whereby a manufacturable high modulus glass fiberization process is sustained.

27. The process of claim 26, wherein the composition comprises between about 49 to about 64 weight percent Si0₂; between about 17 to about 23 weight percent Al₂0₃, wherein the weight percent ratio of Si0₂/Al₂0₃ is between about 2.4 to about 3.5; between about 6 to about 14 weight percent MgO; between about 3 to about 8 weight percent CaO, wherein the weight percent ratio of MgO/CaO is between about 1 .1 to about 4.0; between about 0 to about 1 weight percent Na₂0; between about 4 to about 13 weight percent Y₂0₃; between about 0 to about 3 weight percent Ti0₂; and between about 0.01 to about 5 weight percent Zr0₂.

28. The process of claim 26, wherein the composition has a fiberizing temperature of greater than about 1250° C.

29. The process of claim 26, wherein the glass fiber has a Young's

Modulus of at least 90 GPa.

30. The process of claim 26, wherein the glass fiber has a Young's

Modulus of at least 95 GPa.

31. A fiberglass reinforced article comprising:

glass fibers comprising:

between about 45 to about 65 weight percent Si0₂;

between about 5 to about 15 weight percent MgO;

between about 0 to about 1 weight percent Na₂0;

between about 0.01 to about 14.5 weight percent Υ₂0₃; between about 0 to about 3 weight percent Ti0₂;

between about 0 to about 5 weight percent Zr0₂; and

a matrix material.

32. The fiberglass reinforced article of claim 3 , wherein the glass fibers comprise between about 49 to about 64 weight percent Si0₂; between about 17 to about 23 weight percent Al₂0₃, wherein the weight percent ratio of Si0₂/Al₂0₃ is between about 2.4 to about 3.5; between about 6 to about 14 weight percent MgO; between about 3 to about 8 weight percent CaO, wherein the weight percent ratio of MgO/CaO is between about 1.1 to about 4.0; between about 0 to about 1 weight percent Na₂0; between about 4 to about 13 weight percent Y₂0₃; between about 0 to about 3 weight percent Ti0₂; and between about 0.01 to about 5 weight percent Zr0₂.

33. The fiberglass reinforced article of claim 31 , wherein the glass fibers of the fiberglass reinforced article have a strand tensile modulus of greater than about 90 GPa.

34. The fiberglass reinforced article of claim 31 , wherein the glass fibers of the fiberglass reinforced article have a strand tensile modulus of greater than about

95 GPa.