Abstract: According to the invention, a method of manufacturing an esterified substance including a process in which a copolymer is obtained by copolymerizing a 1-alkene having 5 to 80 carbon atoms and maleic anhydride, and a process in which an esterification reaction of the copolymer and an alcohol having 5 to 25 carbon atoms is caused in a presence of trifluoromethanesulfonic acid in order to obtain a reaction mixture containing an esterified substance including at least one repetition unit selected from formulae (c) to (f) is provided, and, in the formulae (c) to (f), R represents an aliphatic hydrocarbon group having 3 to 78 carbon atoms, R2 represents a hydrocarbon group having 5 to 25 carbon atoms, m represents the copolymerization molar ratio X/Y of the 1-alkene (X) to the maleic anhydride (Y) and is 1/2 to 10/1, and n is an integer of more than or equal to 1.

Abstract: A resin composition having high Tg (high heat resistance), low thermal expansion, and excellent flame retardancy, and being advantageous for promoting halogen-free, and having excellent adhesiveness with Cu, a prepreg obtained by impregnating it into substrate, and a composite and a laminate obtained from them. Specifically provided are a modified polyimide resin composition containing (A) a polymaleimide compound of formula [1], (B) epoxy resin having at least two glycidyl groups in the molecule of formula [2], and (c) phenolic compound having at least two OH groups in the molecule, and a prepreg obtained by impregnating the composition into the substrate, and a composite and a laminate obtained from the prepreg.

Abstract: According to the invention, a method of manufacturing an esterified substance including a process in which a copolymer is obtained by copolymerizing a 1-alkene having 5 to 80 carbon atoms and maleic anhydride, and a process in which an esterification reaction of the copolymer and an alcohol having 5 to 25 carbon atoms is caused in a presence of trifluoromethanesulfonic acid in order to obtain a reaction mixture containing an esterified substance including at least one repetition unit selected from formulae (c) to (f) is provided, and, in the formulae (c) to (f), R represents an aliphatic hydrocarbon group having 3 to 78 carbon atoms, R2 represents a hydrocarbon group having 5 to 25 carbon atoms, m represents the copolymerization molar ratio X/Y of the 1-alkene (X) to the maleic anhydride (Y) and is 1/2 to 10/1, and n is an integer of more than or equal to 1.

Abstract: A method of sealing a semiconductor element which involves applying an epoxy resin composition including an epoxy resin and a phenolic resin obtained by reacting phenol, a biphenyl compound represented by the general formula (3) and benzaldehyde to a semiconductor element and curing the composition to seal the semiconductor element: wherein X in the formula (3) is a halogen, an OH group or an OCH3 group. The molar ratio of the total of the biphenyl compound and benzaldehyde relative to the phenol is from 0.27 to 0.40, and the molar ratio of benzaldehyde/biphenyl compound is from 5/95 to 40/60.

Abstract: A method of sealing a semiconductor element which involves applying an epoxy resin composition including an epoxy resin and a phenolic resin obtained by reacting phenol, a biphenyl compound represented by the general formula (3) and benzaldehyde to a semiconductor element and curing the composition to seal the semiconductor element: wherein X in the formula (3) is a halogen, an OH group or an OCH3 group. The molar ratio of the total of the biphenyl compound and benzaldehyde relative to the phenol is from 0.27 to 0.40, and the molar ratio of benzaldehyde/biphenyl compound is from 5/95 to 40/60.

Abstract: Disclosed is a phenolic resin having flame retardance, fast curing property and low melt viscosity, which is useful for a curing agent for epoxy resin-based semiconductor sealing materials. Also disclosed are a method for producing such a phenolic resin and use of such a phenolic resin. Specifically disclosed is a phenolic resin obtained by reacting a phenol, a bismethylbiphenyl compound and an aromatic aldehyde at such a ratio that the molar ratio of the total of the bismethylbiphenyl compound and the aromatic aldehyde relative to the phenol is 0.10-0.60, and the aromatic aldehyde/the bismethylbiphenyl compound (molar ratio) is from 5/95 to 50/50. Also specifically disclosed is an epoxy resin composition composed of such a phenolic resin and an epoxy resin.

Abstract: Disclosed is a phenolic resin having flame retardance, fast curing property and low melt viscosity, which is useful for a curing agent for epoxy resin-based semiconductor sealing materials. Also disclosed are a method for producing such a phenolic resin and use of such a phenolic resin. Specifically disclosed is a phenolic resin obtained by reacting a phenol, a bismethylbiphenyl compound and an aromatic aldehyde at such a ratio that the molar ratio of the total of the bismethylbiphenyl compound and the aromatic aldehyde relative to the phenol is 0.10-0.60, and the aromatic aldehyde/the bismethylbiphenyl compound (molar ratio) is from 5/95 to 50/50. Also specifically disclosed is an epoxy resin composition composed of such a phenolic resin and an epoxy resin.

Abstract: A phenolic resin obtained by reacting a phenol with an aromatic aldehyde and a xylylene compound represented by the formulaROH.sub.2 C(C.sub.6 H.sub.4)CH.sub.2 ORwhere R is hydrogen, an alkyl group having a carbon atom number of 1-4, or an acyl group having a carbon atom number of 2-4 in the presence of acid catalyst, with the sum of aromatic aldehydes and xylylene compounds to phenols molar ratio being 0.1-0.95, and the xylylene compounds to aromatic aldehydes molar ratio being 0.1-1.4.The phenolic resin thus obtained is useful as an industrial material by virtue of its excellent moisture resisting property, alkali resistance and fair thermosetting property. Having low moisture absorption ratio and high glass transition temperature, this phenolic resin is also suitable used as hardener for semiconductor encapsulating epoxy resin which has excellent package crack resistance after solder dipping and high reliability.

Abstract: A heat-resistant, electrical insulating layer which is suitable for use as an insulating substrate in printed circuit boards and as an insulating film for semiconductor devices and which surpasses a polyimide-based insulating layer with respect to heat resisting properties, dielectric properties, and water absorption. The insulating layer comprises a polycondensed fused polycyclic, polynuclear aromatic resin prepared by a polycondensation reaction of a starting material with a crosslinking agent in the presence of an acid catalyst. The starting material is selected from the group consisting of fused polycyclic aromatic hydrocarbons which may have a hydroxyl group as a ring substituent and mixtures of a fused polycyclic aromatic hydrocarbon and a monocyclic aromatic hydrocarbon both of which may have a hydroxyl group as a ring substituent. The crosslinking agent is an aromatic compound having at least two hydroxymethyl or halomethyl groups as ring substituents.

Abstract: A condensed polycyclic, polynuclear aromatic thermosetting resin with improved moldability which is prevented from forming a cloud on a mold during molding is disclosed. The resin is a prepolymer derived by condensation polymerization of a condensed polycyclic aromatic compound or a mixture thereof with a monocyclic aromatic compounds and an aromatic compound having at least two hydroxymethyl groups as a crosslinking agent in the presence of an acid catalyst. The resin has a flow temperature of not higher than 150.degree. C. The acid catalyst is water-insoluble or when it is water-soluble the resin has an insolubilized acid ratio of at least 50%. The resin is useful in the manufacture of thermoset molded articles having good heat resistance and good mechanical and electrical properties. It can be blended with a filler and/or reinforcing agent to form a molding compound.