A laminate sheet article including: a core including an electrical semi-conductor or an electrical conductor; and a continuous glass clad layer on at least four of six sides the core of the sheet article. Also disclosed is an apparatus for making a sheet laminate article as defined herein. Also disclosed is a method of making and using the article.

A laminate sheet article including: a core including an electrical semi-conductor or an electrical conductor; and a continuous glass clad layer on at least four of six sides the core of the sheet article. Also disclosed is an apparatus for making a sheet laminate article as defined herein. Also disclosed is a method of making and using the article.

A glass composition comprises: 50.0 mol % to 70.0 mol % SiO.sub.2; 10.0 mol % to 25.0 mol % Al.sub.2O.sub.3; 0.0 mol % to 5.0 mol % P.sub.2O.sub.5; 0.0 mol % to 10.0 mol % B.sub.2O.sub.3; 5.0 mol % to 15.0 mol % Li.sub.2O; 1.0 mol % to 15.0 mol % Na.sub.2O; and 0.0 mol % to 1.0 mol % K.sub.2O. The sum of all alkali oxides, R.sub.2O, present in the glass composition may be in the range from greater than or equal to 11.0 mol % to less than or equal to 23.0 mol %. The sum of Al.sub.2O.sub.3 and R.sub.2O present in the glass composition may be in the range from greater than or equal to 26.0 mol % to less than or equal to 40.0 mol %. The glass composition may satisfy the relationship −0.1≤(Al.sub.2O.sub.3—(R.sub.2O+RO))/Li.sub.2O≤0.3.

A glass composition comprises: 50.0 mol % to 70.0 mol % SiO.sub.2; 10.0 mol % to 25.0 mol % Al.sub.2O.sub.3; 0.0 mol % to 5.0 mol % P.sub.2O.sub.5; 0.0 mol % to 10.0 mol % B.sub.2O.sub.3; 5.0 mol % to 15.0 mol % Li.sub.2O; 1.0 mol % to 15.0 mol % Na.sub.2O; and 0.0 mol % to 1.0 mol % K.sub.2O. The sum of all alkali oxides, R.sub.2O, present in the glass composition may be in the range from greater than or equal to 11.0 mol % to less than or equal to 23.0 mol %. The sum of Al.sub.2O.sub.3 and R.sub.2O present in the glass composition may be in the range from greater than or equal to 26.0 mol % to less than or equal to 40.0 mol %. The glass composition may satisfy the relationship −0.1≤(Al.sub.2O.sub.3—(R.sub.2O+RO))/Li.sub.2O≤0.3.

Embodiments are directed to glass articles which are resistant to UV photodarkening, the glass articles having a thickness ≤1.3 mm and comprise UV absorbers such as Ti, V, Mn, Fe, Cu, Ce, Ge, Mo, Cr, Co and Ni, and combinations thereof, or alternatively comprising ZnO or SnO.sub.2.

Embodiments are directed to glass articles which are resistant to UV photodarkening, the glass articles having a thickness ≤1.3 mm and comprise UV absorbers such as Ti, V, Mn, Fe, Cu, Ce, Ge, Mo, Cr, Co and Ni, and combinations thereof, or alternatively comprising ZnO or SnO.sub.2.

A cover glass of the present invention is characterized by including in a glass composition at least three or more components selected from SiO.sub.2, Al.sub.2O.sub.3, B.sub.2O.sub.3, Li.sub.2O, Na.sub.2O, K.sub.2O, MgO, CaO, BaO, TiC.sub.2, Y.sub.2O.sub.3, ZrO.sub.2, and P.sub.2O.sub.5, and having an X value of 7, 400 or more calculated by the following equation. The X value is a value calculated by the equation

X=61.1×[SiO.sub.2]+174.3×[Al.sub.2O.sub.3]+11.3×[B.sub.2O.sub.3]+124.7×[Li.sub.2O]−5.2×[Na.sub.2O]+226.7×[K.sub.2O]+139.4×[MgO]+117.5×[CaO]+89.6×[BaO]+191.8×[TiO.sub.2]+226.7×[Y.sub.2O.sub.3]+157.9×[ZrO.sub.2]−42.2×[P.sub.2O.sub.5].

A cover glass of the present invention is characterized by including in a glass composition at least three or more components selected from SiO.sub.2, Al.sub.2O.sub.3, B.sub.2O.sub.3, Li.sub.2O, Na.sub.2O, K.sub.2O, MgO, CaO, BaO, TiC.sub.2, Y.sub.2O.sub.3, ZrO.sub.2, and P.sub.2O.sub.5, and having an X value of 7, 400 or more calculated by the following equation. The X value is a value calculated by the equation

X=61.1×[SiO.sub.2]+174.3×[Al.sub.2O.sub.3]+11.3×[B.sub.2O.sub.3]+124.7×[Li.sub.2O]−5.2×[Na.sub.2O]+226.7×[K.sub.2O]+139.4×[MgO]+117.5×[CaO]+89.6×[BaO]+191.8×[TiO.sub.2]+226.7×[Y.sub.2O.sub.3]+157.9×[ZrO.sub.2]−42.2×[P.sub.2O.sub.5].

The invention relates to glass-ceramics based on the lithium silicate system which can be mechanically machined easily in an intermediate step of crystallization and, after complete crystallisation, represent a very strong, highly-translucent and chemically-stable glass-ceramic Likewise, the invention relates to a method for the production of these glass-ceramics. The glass-ceramics according to the invention are used as dental material.

The invention relates to glass-ceramics based on the lithium silicate system which can be mechanically machined easily in an intermediate step of crystallization and, after complete crystallisation, represent a very strong, highly-translucent and chemically-stable glass-ceramic Likewise, the invention relates to a method for the production of these glass-ceramics. The glass-ceramics according to the invention are used as dental material.