Abstract: In a liquid epoxy resin composition comprising a liquid epoxy resin, a curing agent, a curing accelerator, and an inorganic filler, the liquid epoxy resin is a mixture of (a) a liquid epoxy resin containing two or less epoxy functional groups and (b) a solid epoxy resin containing two or more epoxy functional groups in a weight ratio (a)/(b) of from 9/1 to 1/4, having a viscosity of up to 10,000 poises at 25° C. as measured by an E type viscometer. The composition is adherent to silicon chips, the cured product is highly resistant to humidity and thermal shocks, and the composition is useful as sealant for semiconductor devices.

Abstract: An adhesive in the form of a liquid epoxy resin composition comprising (A) a liquid epoxy resin, (B) 20 to 90% by weight based on the entire composition of an inorganic filler having an average particle size from more than 1 &mgr;m to 20 &mgr;m and containing up to 1% by weight of a fraction of particles having a particle size of at least 45 &mgr;m and optionally, (C) a silicone-modified resin is suitable for bonding optical elements in optical devices.

Abstract: In a liquid epoxy resin composition comprising a liquid epoxy resin, a curing agent, a curing accelerator, and an inorganic filler, the liquid epoxy resin is a mixture of (a) a liquid epoxy resin containing two or less epoxy functional groups and (b) a solid epoxy resin containing two or more epoxy functional groups in a weight ratio (a)/(b) of from 9/1 to 1/4, having a viscosity of up to 10,000 poises at 25° C. as measured by an E type viscometer. The composition is adherent to silicon chips, the cured product is highly resistant to humidity and thermal shocks, and the composition is useful as sealant for semiconductor devices.

Abstract: An adhesive in the form of a liquid epoxy resin composition comprising (A) a liquid epoxy resin, (B) 20 to 90% by weight based on the entire composition of an inorganic filler having an average particle size from more than 1 &mgr;m to 20 &mgr;m and containing up to 1% by weight of a fraction of particles having a particle size of at least 45 &mgr;m and optionally, (C) a silicone-modified resin is suitable for bonding optical elements in optical devices.

Abstract: There is disclosed a method for producing a porous optical fiber base material comprising depositing fine glass powder on a rotating member, wherein pore size of the deposited fine glass powder is controlled, and preferably, mode of the pore size is controlled to be 0.1 to 1 &mgr;m, or wherein a total amount of absorbed H2O amount and OH group amount on the fine glass powder per square meter of fine glass powder surface area is controlled to be 3.5×10−5 to 7.5×10−5 g. Such porous optical fiber base materials have an improved weight of fine glass powder deposited on the member per batch, or an improved fine glass powder deposit efficiency, which may greatly contribute to improvement of production ability and reduction of production cost.

Abstract: High-packing silicon nitride powder having a tap density of at least about 0.9 g/cm.sup.3 is prepared by reacting a metallic silicon powder having a mean particle size of about 1 to 10 .mu.m, a BET specific surface area of about 1 to 5 m.sup.2 /g, and a purity of at least about 99% with nitrogen in a nitrogen atmosphere containing about 5 to 20% by volume of hydrogen at about 1,350 to 1,450.degree. C., and milling the resulting silicon nitride powder in a dry attritor. The powder is moldable into a compact having a density of at least about 1.70 g/cm.sup.3, from which a sintered part having improved dimensional precision and strength is obtained.

Abstract: High-packing silicon nitride powder is prepared by reacting metallic silicon powder having a mean particle size of 1 to 10 .mu.m and a purity of at least 99% directly with nitrogen for forming silicon nitride powder, milling the silicon nitride powder in a dry attritor until the tap density exceeds 0.9 g/cm.sup.3 and the content of particles having an aspect ratio of up to 3 exceeds 95% by weight, and further milling the silicon nitride powder in a wet attritor for finely dividing coarse particles having a particle size of at least 2 .mu.m. The silicon nitride powder has a tap density of at least 0.9 g/cm.sup.3 and a mean particle size of 0.4 to 0.6 .mu.m and contains at least 95% by weight of particles having an aspect ratio of up to 3 and up to 5% by weight of coarse particles having a particle size of at least 2 .mu.m. The powder is moldable into a high density compact, from which a sintered part having improved dimensional precision and strength is obtained.