The present disclosure provides a novel glass composition that has a low permittivity and is suitable for mass production. A glass composition provided satisfies, in wt %, for example, 40≤SiO.sub.2≤60, 25≤B.sub.2O.sub.3≤45, 0<Al.sub.2O.sub.3≤18, 0<R.sub.2O≤5, and 0≤RO≤12, and satisfies at least one of: i) SiO.sub.2+B.sub.2O.sub.3≥80 and SiO.sub.2+B.sub.2O.sub.3+Al.sub.2O.sub.3≤99.9; and ii) SiO.sub.2+B.sub.2O.sub.3≥78, SiO.sub.2+B.sub.2O.sub.3+Al.sub.2O.sub.3≤99.9, and 0<RO<10. Another glass composition provided includes SiO.sub.2, B.sub.2O.sub.3, Al.sub.2O.sub.3, R.sub.2O, and 3<RO<8 at the same contents as the above, and satisfies SiO.sub.2+B.sub.2O.sub.3≥75 and SiO.sub.2+B.sub.2O.sub.3+Al.sub.2O.sub.3<97, where R.sub.2O═Li.sub.2O+Na.sub.2O+K.sub.2O and RO═MgO+CaO+SrO.

Provided is a composition for a glass fiber having a high elastic modulus and satisfactory productivity. The composition for a glass fiber includes, in terms of mass %, 0% to 1% of Li.sub.2O+Na.sub.2O+K.sub.2O, and has SiO.sub.2/Al.sub.2O.sub.3 of from 1 to 4 and MgO/CaO of from 0.2 to 3.9 in terms of mass ratio.

An electronic-grade glass fiber composition includes the following components with corresponding amounts by weight percentages 51.0-57.5% SiO.sub.2, 11.0-17.0% Al.sub.2O.sub.3, >4.5% and ≤6.4% B.sub.2O.sub.3, 19.5-24.8% CaO, 0.1-1.9% MgO, 0.05-1.2% R.sub.2O=Na.sub.2O+K.sub.2O+Li.sub.2O, 0.05-0.8% Fe.sub.2O.sub.3, 0.01-1.0% TiO.sub.2, and 0.01-1.0% F.sub.2. A weight percentage ratio C1=SiO.sub.2/B.sub.2O.sub.3 is 8.1-12.7, a weight percentage ratio C2=B.sub.2O.sub.3/(R.sub.2O+MgO) is 1.7-6.3, and a total weight percentage of the above components is greater than or equal to 99%.

Glass compositions suitable for fiber forming and glass fibers having a high modulus are disclosed. The glass composition may include SiO.sub.2 from about 48 to about 61 weight percent, Al.sub.2O.sub.3 from about 22 to about 27 weight percent, CaO from about 1 to about 11 weight percent, MgO from about 5 to about 20 weight percent, less than 5.5 weight percent Y.sub.2O.sub.3, up to 2.5 weight percent Li.sub.2O, and up to 1 weight percent B.sub.2O.sub.3. The glass compositions can be used to form glass fibers and incorporated into various composites.

The present disclosure provides a novel glass composition that has a low permittivity and is suitable for mass production. A glass composition provided satisfies, in wt %, for example, 40≤SiO.sub.2≤60, 25≤B.sub.2O.sub.3≤45, 0<Al.sub.2O.sub.3≤18, 0<R.sub.2O≤5, and 0≤RO≤12, and satisfies at least one of: i) SiO.sub.2+B.sub.2O.sub.3≥80 and SiO.sub.2+B.sub.2O.sub.3+Al.sub.2O.sub.3≤99.9; and ii) SiO.sub.2+B.sub.2O.sub.3≥78, SiO.sub.2+B.sub.2O.sub.3+Al.sub.2O.sub.3≤99.9, and 0<RO<10. Another glass composition provided includes SiO.sub.2, B.sub.2O.sub.3, Al.sub.2O.sub.3, R.sub.2O, and 3<RO<8 at the same contents as the above, and satisfies SiO.sub.2+B.sub.2O.sub.3≥75 and SiO.sub.2+B.sub.2O.sub.3+Al.sub.2O.sub.3<97, where R.sub.2O=Li.sub.2O+Na.sub.2O+K.sub.2O and RO=MgO+CaO+SrO.

The present invention relates to a process for producing insulating products based on mineral fibers, in particular on mineral wool, comprising providing a first binder composition containing (a) from 50% to 85% by weight of water, preferably from 70 to 82% of water (b) from 10% to 45% by weight, preferably 15 to 35% by weight of a saccharide component containing sucrose, (c) from 3% to 15% by weight, preferably from 5 to 12% by weight of one or more ammonium salts or primary amine salts of an acid, preparing a second binder composition comprising the dilution of the first aqueous binder composition with water to a solids content of between 3 and 7% by weight, applying the second binder composition to mineral fibers, forming an assembly of mineral fibers coated with the second binder composition, and heating the assembly of coated mineral fibers so as to form an assembly of mineral fibers bound by an insoluble binder,
said process being characterized in that the first aqueous binder composition has a pH of less than 5.5, in that the ammonium salt or primary amine salt is a salt of strong acid or a salt of an acid having a pKa of less than or equal to 2.2, and in that the first and second binder compositions are devoid of salts of weak acids having at least a pKa of between 2.5 and 6.9.

A fiber optic imaging element includes medium-expansion and a fabrication method including: (1) matching a core glass rod with a cladding glass tube to perform mono fiber drawing; (2) arranging the mono fibers into a mono fiber bundle rod, and then drawing the mono fiber bundle rod into a multi fiber; (3) arranging the multi fiber into a multi fiber bundle rod, and then drawing the multi fiber bundle rod into a multi-multi fiber; (4) cutting the multi-multi fiber, and then arranging the multi-multi fiber into a fiber assembly buddle, then putting the fiber assembly buddle into a mold of heat press fusion process, and performing the heat press fusion process to prepare a block of the fiber optic imaging element with medium-expansion; and (5) edged rounding, cutting and slicing, face grinding and polishing the prepared medium-expansion block into a billet.

The invention relates to an aqueous binder composition for mineral fibers comprising at least one polyelectrolytic hydrocolloid.

A glass composition includes 59.00 to 65.00% by mass of SiO.sub.2, 16.00 to 26.00% by mass of B.sub.2O.sub.3, 7.00 to 14.00% by mass of Al.sub.2O.sub.3, 0 to 5.00% by mass of CaO, 0 to 4.00% by mass of MgO, 0 to 6.00% by mass of SrO, 0.10 to 5.00% by mass of TiO.sub.2, 0 to 2.00% by mass of F.sub.2 and Cl.sub.2 in total, less than 0.20% by mass of P.sub.2O.sub.5, and less than 1.00% by mass of Na.sub.2O, K.sub.2O and Li.sub.2O in total, wherein the ratio of TiO.sub.2 to the total content of CaO, MgO, and SrO (TiO.sub.2/(CaO+MgO+SrO)) is from 0.66 to 4.00, and the content SI of SiO.sub.2 and the content A of Al.sub.2O.sub.3 satisfy the following formula (1): 1.00≤1000×A/SI.sup.2≤4.65 (1).

A glass composition for glass fiber includes 50.00 to 61.00% by mass of SiO.sub.2, 16.00 to 27.00% by mass of B.sub.2O.sub.3, 7.00 to 14.00% by mass of Al.sub.2O.sub.3, 0.20 to 4.00% by mass of P.sub.2O.sub.5, 0.50 to 5.00% by mass of TiO.sub.2, 0.10 to 5.00% by mass of CaO, 0 to 4.00% by mass of MgO, and 0 to 2.00% by mass of F.sub.2 and Cl.sub.2 in total, with respect to the total amount of the glass composition for glass fiber, and the content S of SiO.sub.2, the content A of Al.sub.2O.sub.3, the content P of P.sub.2O.sub.5, the content T of TiO.sub.2, the content C of CaO, and the content M of MgO satisfy the following formula (1):

3.65≤(S/A).sup.2×(P×T).sup.1/2/(C+M).sup.3≤8.25  (1).