Abstract: It is an object of the present invention to provide a clad glass composition for graded-index rod lens for covering, during manufacturing, a preform glass composition lens of a graded-index rod lens that does not include PbO, in which the composition substantially does not include PbO, and expressed in mol % includes SiO2: 45 to 65, Na2O: 3 to 30, K2O: 0 to 10, MgO: 0 to 15, BaO: 0 to 20, where Na2O+K2O: 3 to 35 and MgO+BaO: 0 to 25, and furthermore includes B2O3: 0 to 15, ZnO: 0 to 10, TiO2: 0 to 10, Y2O3: 0 to 7, ZrO2: 0 to 7, Nb2O5: 0 to 7, In2O3: 0 to 7, La2O3: 0 to 7, Ta2O5: 0 to 10, where B2O3+ZnO+TiO2+Y2O3+ZrO2+Nb2O5+In2O3+La2to 20, and a content of at least one of TiO2 and La2O3 is substantially 0 mol %.

Abstract: The present invention provides a raw material composition for soda-lime glass capable of effectively suppressing formation of nickel sulfide (NiS) in the course of melting of the glass raw material. A nickel sulfide (NiS) impurity present in soda-lime glass is formed in a high-temperature vitrification step in which metal particles containing Ni and an Ni component of stainless steel used for the interior of a melting furnace, which are mixed into glass raw material, react at high temperature with a sulfur (S) component in Na2SO4 serving as a glass raw material. However, when an additive containing an oxide, a chloride, a sulfate, or a nitrate of a metal is added in a very small amount and in advance to glass raw material, formation of NiS by the reaction between Ni and S in the course of melting can be suppressed or completely eliminated.

Abstract: It is an object of the present invention to provide a clad glass composition for graded-index rod lens for covering, during manufacturing, a preform glass composition lens of a graded-index rod lens that does not include PbO, in which the composition substantially does not include PbO, and expressed in mol % includes SiO2: 45 to 65, Na2O: 3 to 30, K2O: 0 to 10, MgO: 0 to 15, BaO: 0 to 20, where Na2O+K2O: 3 to 35 and MgO+BaO: 0 to 25, and furthermore includes B2O3: 0 to 15, ZnO: 0 to 10, TiO2: 0 to 10, Y2O3: 0 to 7, ZrO2: 0 to 7, Nb2O5: 0 to 7, In2O3: 0 to 7, La2O3: 0 to 7, Ta2O5: 0 to 10, where B2O3+ZnO+TiO2+Y2O3+ZrO2+Nb2O5+In2O3+La2O3+Ta2O5: 0 to 20, and a content of at least one of TiO2 and La2O3 is substantially 0 mol %.

Abstract: The present invention can provide an alkali free glass containing as a refining agent, a tin oxide and at least one selected from the group consisting of a cerium oxide, a manganese oxide, a tungsten oxide, a tantalum oxide and a niobium oxide.

Abstract: A method of bonding respective objects made of different kinds of material to each other is disclosed. The method includes the steps of (A) contacting a bonding material in the fluid state thereof with respective bonding faces of the respective objects to be bonded, (B) mechanically abrading portions of the respective bonding faces contacting the bonding material to be bonded to each other, (C) setting the respective objects fixed in a predetermined position relative to each other while maintaining the respective objects in contact with the bonding material in the fluid state thereof, and (D) solidifying the bonding material to bond the respective objects to each other. In the respective steps (A)-(D), the bonding material is present at the bonding portions to be bonded to each other of the respective objects constantly and without discontinuities.

Abstract: The present invention can provide an alkali free glass containing as a refining agent, a tin oxide and at least one selected from the group consisting of a cerium oxide, a manganese oxide, a tungsten oxide, a tantalum oxide and a niobium oxide.

Abstract: A method of bonding respective objects made of different kinds of material to each other is disclosed. The method includes the steps of (A) contacting a bonding material in the fluid state thereof with respective bonding faces of the respective objects to be bonded, (B) mechanically abrading portions of the respective bonding faces contacting the bonding material to be bonded to each other, (C) setting the respective objects fixed in a predetermined position relative to each other while maintaining the respective objects in contact with the bonding material in the fluid state thereof, and (D) solidifying the bonding material to bond the respective objects to each other. In the respective steps (A)-(D), the bonding material is present at the bonding portions to be bonded to each other of the respective objects constantly and without discontinuities.

Abstract: Glass for vehicles comprising from 65 to 80% by weight of SiO.sub.2, from 0 to 5% by weight of Al.sub.2 O.sub.3, from 0 to 5% by weight B.sub.2 O.sub.3, from 0 to 10% by weight of MgO, from 5 to 15% by weight of CaO, from 10 to 18% by weight of Na.sub.2 O, from 0 to 5% by weight of K.sub.2 O, from 5 to 15% by weight in total of MgO and CaO, from 10 to 20% by weight in total of Na.sub.2 O and K.sub.2 O, from 0.1 to 1% by weight of cerium oxide in terms of CeO.sub.2, from 0.2 to 0.6% by weight of iron oxide in terms of Fe.sub.2 O.sub.3, from 0 to 0.005% by weight of CoO, from 0 to 0.01% by weight of NiO, and from 0.0005 to 0.005% by weight of Se, and glass for vehicles comprising from 65 to 80% by weight of SiO.sub.2, from 0 to 5% by weight of Al.sub.2 O.sub.3, from 0 to 5% by weight of B.sub.2 O.sub.3, from to 10% by weight of MgO, from 5 to 15% by weight of CaO, from 10 to 18% by weight of Na.sub.2 O, from 0 to 5% by weight of K.sub.

Abstract: Glass for vehicles comprising from 65 to 80% by weight of SiO.sub.2, from 0 to 5% by weight of Al.sub.2 O.sub.3, from 0 to 5% by weight of B.sub.2 O.sub.3, from 0 to 10% by weight of MgO, from 5 to 15% by weight of CaO, from 10 to 18% by weight of Na.sub.2 O, from 0 to 5% by weight of K.sub.2 O, from 5 to 15% by weight in total of MgO and CaO, from 10 to 20% by weight in total of Na.sub.2 O and K.sub.2 O, from 0.1 to 1% by weight of cerium oxide in terms of CeO.sub.2, from 0.2 to 0.6% by weight of iron oxide in terms of Fe.sub.2 O.sub.3, from 0 to 0.005% by weight of CoO, from 0 to 0.01% by weight of NiO, from 0.2 to 3% by weight of Er.sub.2 O.sub.3, and from 0.0003 to 0.005% by weight of Se. The glass assumes bronze while exhibiting excellent ultraviolet and heat absorption.