Abstract: A resin composition contains an epoxy resin, and a curing agent including a first acid anhydride and a second acid anhydride. An unsaturated bond concentration in the second acid anhydride is not higher than 0.7%. The unsaturated bond concentration is represented by following formula (1). The ratio of the number of acid anhydride equivalents of the first acid anhydride to the number of epoxy equivalents of the epoxy resin is between 0.05 and 0.5 (inclusive). The ratio of the total number of acid anhydride equivalents of the first acid anhydride and the second acid anhydride to the number of epoxy equivalents is between 0.5 and 1.1 (inclusive).

Abstract: A resin composition contains an epoxy resin, and a curing agent including a first acid anhydride and a second acid anhydride. An unsaturated bond concentration in the second acid anhydride is not higher than 0.7%. The unsaturated bond concentration is represented by following formula (1). The ratio of the number of acid anhydride equivalents of the first acid anhydride to the number of epoxy equivalents of the epoxy resin is between 0.05 and 0.5 (inclusive). The ratio of the total number of acid anhydride equivalents of the first acid anhydride and the second acid anhydride to the number of epoxy equivalents is between 0.5 and 1.1 (inclusive).

Abstract: Resin composition of the present disclosure includes: an epoxy resin; and a hardener, in which the hardener contains a styrene-maleic anhydride copolymer (SMA) and an anhydride having only one anhydride group in a molecule. An acid value of the SMA is in a range from 300 to 550, inclusive. A ratio of an anhydride equivalent number of the anhydride with respect to an epoxy group equivalent number of the epoxy resin is in a range from 0.05 to 0.5, inclusive. A ratio of the total number of the equivalent numbers of the anhydride groups of the anhydride and the SMA with respect to the epoxy group equivalent number is a range from 0.5 to 1.2, inclusive.

Abstract: Resin composition of the present disclosure includes: an epoxy resin; and a hardener, in which the hardener contains a styrene-maleic anhydride copolymer (SMA) and an anhydride having only one anhydride group in a molecule. An acid value of the SMA is in a range from 300 to 550, inclusive. A ratio of an anhydride equivalent number of the anhydride with respect to an epoxy group equivalent number of the epoxy resin is in a range from 0.05 to 0.5, inclusive. A ratio of the total number of the equivalent numbers of the anhydride groups of the anhydride and the SMA with respect to the epoxy group equivalent number is a range from 0.5 to 1.2, inclusive.

Abstract: An epoxy resin composition for use in producing a prepreg for printed wiring boards excellent in appearance, flame retardancy, etc., which comprises an epoxy resin, a phenolic novolak, and a curing accelerator. It is characterized in that the epoxy resin comprises an epoxy (a) and an epoxy (b), wherein the epoxy (a) is a brominated epoxy resin which is obtained by reacting/mixing a bisphenol A epoxy resin with tetrabromobisphenol A and has an epoxy equivalent of 350 to 470 g/eq and an n=0 component content of 20 to 35% in terms of areal percentage in a GPC chart, and the epoxy (b) is at least one bifunctional epoxy resin which is obtained by reacting any one selected from the group consisting of bisphenol A, bisphenol F, and tetrabromobisphenol A with epichlorohydrin and has an n=0 component content as determined from a GPC chart of 60% or higher.

Abstract: An epoxy resin composition for a prepreg used in manufacturing a printed wiring board, particularly a multilayered printed wiring board, is provided. The composition features: (A) a multifunctional epoxy resin having on average 2.8 or more epoxy groups per molecule; (B) a reaction product of a phosphorous compound, a bifunctional epoxy resin, and an optional multifunctional epoxy resin, provided in an amount of 20% to 55% by mass, based on the total amount of epoxy resin, including (A) and (B); (C) a curing agent of dicyandiamide and/or a multifunctional phenolic compound; and (D) an inorganic filler blend containing an inorganic filler with a thermal decomposition temperature of 400° C. or above. The composition does not generate toxic substances when combusted and has excellent ignition resistance, solder heat resistance after moisture absorption, and high temperature rigidity.

Abstract: An epoxy resin composition for printed wiring boards which comprises an epoxy resin, a phenolic novolak, a curing accelerator, and a silica filler, characterized in that the silica filler has a shape having at least two planes and has an average particle diameter of 0.3 to 10 ?m and a specific surface area of 8 to 30 m2/g. The epoxy resin composition has a higher apparent viscosity than the resins and can hence be inhibited from sagging in a drying oven. This composition retains the intact property of infiltration into reinforcements because the viscosity of the resins themselves has not increased locally. The composition hence produces the effect of improving the appearance of a prepreg.

Abstract: Problems: To provide an epoxy resin composition for prepreg used in manufacturing a printed wiring board, particularly a multilayered printed wiring board, which does not generate toxic substance on combustion and excellent in ignition resistance, solder heat resistance after moisture absorption and high temperature rigidity, prepregs and multilayered printed wiring boards. Means for solving problems: A phosphorous compound comprising 1.8 or more but less than 3 phenolic hydroxyl groups on an average and 0.8 or more phosphorous atom on an average within a molecule is reacted in advance with a particular bifunctional epoxy resin (selected from biphenyl, naphthalene, dicylcopentadiene or other types) in a ratio of epoxy equivalent to phenolic hydroxyl equivalent to be 1.2 or more but less than 3 to 1 to yield a preliminarily reacted epoxy resin, of which 20% by mass to 55% by mass against the whole epoxy resin composition is formulated together with a multifunctional epoxy resin having 2.

Abstract: A prepreg for a printed wiring board characterized with use of a brominated epoxy resin, possessing a peak intensity of infrared absorption spectrum at 2100 to 2300 cm?1, which is 5% or lower than that of a benzene ring carbon-carbon double bond at 1600 cm?1 as measured with an infrared absorption spectrometer as well as having an inflection point between 120 and 150° C. in the cured product of said brominated epoxy resin as measured by means of a differential scanning calorimeter. The prepreg for the printed wiring board is superior in hygroscopicity, heat resistance, and desmear capability as a printed wiring board material and can be used to manufacture a copper-clad laminate board.

Abstract: An epoxy resin composition for printed wiring boards which comprises an epoxy resin, a phenolic novolak, a curing accelerator, and a silica filler, characterized in that the silica filler has a shape having at least two planes and has an average particle diameter of 0.3 to 10 ?m and a specific surface area of 8 to 30 m2/g. The epoxy resin composition has a higher apparent viscosity than the resins and can hence be inhibited from sagging in a drying oven. This composition retains the intact property of infiltration into reinforcements because the viscosity of the resins themselves has not increased locally. The composition hence produces the effect of improving the appearance of a prepreg.

Abstract: An epoxy resin composition for use in producing a prepreg for printed wiring boards excellent in appearance, flame retardancy, etc., which comprises an epoxy resin, a phenolic novolak, and a curing accelerator. It is characterized in that the epoxy resin comprises an epoxy (a) and an epoxy (b), wherein the epoxy (a) is a brominated epoxy resin which is obtained by reacting/mixing a bisphenol A epoxy resin with tetrabromobisphenol A and has an epoxy equivalent of 350 to 470 g/eq and an n=0 component content of 20 to 35% in terms of areal percentage in a GPC chart, and the epoxy (b) is at least one bifunctional epoxy resin which is obtained by reacting any one selected from the group consisting of bisphenol A, bisphenol F, and tetrabromobisphenol A with epichlorohydrin and has an n=0 component content as determined from a GPC chart of 60% or higher.

Abstract: An epoxy resin composition featured in containing, in a matrix of an epoxy resin having more than two epoxy groups in each molecule, a phenolic hardening agent having more than two phenolic hydroxyl groups in each molecule, an organobis(N-dialkylurea) hardening promotion agent, a solvent for the hardening promotion agent, and a guanamine compound, and capable of obtaining a prepreg excellent in the preservation stability and, less causing a solvency errosion (halo phenomenon) due to an infiltration of plating solution along boundaries between a printed copper circuit formed in an inner-layered circuit board and a resin forming the prepreg, is realized.