Abstract: Compositions of poly(methyl methacrylate) containing alumina trihydrate particularly useful as sheets or other shaped parts in architectural applications such as countertops or wall facings, having improved fire resistance by adding thereto minor amounts of chopped aramid and/or chopped carbon fibers are disclosed.

Abstract: A low-K crystallizable glass composition having a softening point of 550.degree.-800.degree. C., consisting essentially of mole % of:41-70% P.sub.2 O.sub.5 ;10-48% MgO, ZnO or mixtures thereof;2-20% Al.sub.2 O.sub.3, Cr.sub.2 O.sub.3 or mixtures thereof;0-10% alkali metal oxide(s);0-10% CaO, SrO, BaO or mixtures thereof;0-10% SiO.sub.2 ;0-20% B.sub.2 O.sub.3 ;0-10% ZrO.sub.2, TiO.sub.2 or mixtures thereof; and0-10% Fe.sub.2 O.sub.3, with the provisos that:(i) a=n(b+3c+d+e+2f+3g), wherein n=0.8-1.0, anda=mole % P.sub.2 O.sub.5 ;b=mole % MgO, ZnO or mixtures thereof;c=mole % Al.sub.2 O.sub.3, Cr.sub.2 O.sub.3 or mixtures thereof;d=mole % M.sub.2 O, where M=Na, K, Rb, Cse=mole % M'O, where M'=Ca, Sr, Baf=mole % ZrO.sub.2, TiO.sub.2 or mixtures thereof;g=mole % Fe.sub.2 O.sub.3, (where Ln is any of the rare earth elements), or mixtures thereof;(ii) the total amount of alkali oxides, CaO, SrO, and BaO does not exceed 10 mole %;(iii) the total amount of ZrO.sub.2, TiO.sub.2, and Fe.sub.2 O.sub.

Abstract: A crystalline composition having an X-ray diffraction pattern essentially the same as the high cristobalite form of silica comprising SiO.sub.2, Al.sub.2 O.sub.3 and a metal oxide (Me.sub.x O) in which Me is selected from Na, Ca, Sr and mixtures thereof.

Abstract: A composition for making dielectric layers having low dielectric constant, the composition comprising an admixture of finely divided solids comprising lead-free amorphous borosilicate glass and cordierite glass. The dielectric layers are useful in circuits, especially multilayers circuits for high density applications.

Abstract: A high dielectric constant glass-ceramic material comprising small conducting grains based on BaTiO.sub.3 and/or SrTiO.sub.3 on the order of about 0.5-10.0 .mu.m surrounded by a thin microcrystalline insulating barrier layer at the grain boundary about 0.01-0.10 .mu.m thick wherein the conductivity of the grains is enhanced by addition of about 0.1-4.0 mol % of a dopant selected from among Group V elements, Ge and Si substantially incorporated in the bulk lattice of the grains upon Ti sites. A novel process for forming the glass-ceramic material is also disclosed.