Abstract: Disclosed is a process for producing a highly reactive modified phenolic resin, which comprises mixing a heavy oil or pitch with 0.3 to 10 mol of a phenol, 0.2 to 9 mol in terms of formaldehyde, of a formaldehyde compound and 0.01 to 3.0 mol of an acid catalyst, each amount being based on 1 mol of the heavy oil or pitch calculated from an average molecular weight; and heating the resulting mixture with stirring, thereby to polycondensate the heavy oil or pitch, phenol and formaldehyde compound. According to this invention, there can be provided a process for producing simply and stably a highly reactive modified phenolic resin having low melt viscosity, excellent heat resistance and high reactivity with an epoxy resin, in one step.

Abstract: Disclosed is a process for producing a highly reactive modified phenolic resin, which comprises mixing a heavy oil or pitch with 0.3 to 10 mol of a phenol, 0.2 to 9 mol in terms of formaldehyde, of a formaldehyde compound and 0.01 to 3.0 mol of an acid catalyst, each amount being based on 1 mol of the heavy oil or pitch calculated from an average molecular weight; and heating the resulting mixture with stirring, thereby to polycondensate the heavy oil or pitch, phenol and formaldehyde compound. According to this invention, there can be provided a process for producing simply and stably a highly reactive modified phenolic resin having low melt viscosity, excellent heat resistance and high reactivity with an epoxy resin, in one step.

Abstract: A process for producing a highly reactive low-viscosity modified phenolic resin comprising the steps of polycondensating a petroleum heavy oil or pitch, a formaldehyde polymer, and a phenol in the presence of an acid catalyst to prepare a modified phenolic resin; and reacting the resultant modified phenolic resin with the phenols at a temperature higher than 120.degree. C. and not more than 200.degree. C. in the presence of the acid catalyst to lower the molecular weight of the modified phenolic resin. The highly reactive low-viscosity modified phenolic resin obtained according to this process has high reactivity with epoxy resins and low resin melt viscosity. In addition, this resin can be used for producing a molding material having good moldability and considerably low moisture absorption when combined with an epoxy resin.

Abstract: A process for producing a highly reactive low-viscosity modified phenolic resin comprising the steps of polycondensating a petroleum heavy oil or pitch, a formaldehyde polymer, and a phenol in the presence of an acid catalyst to prepare a modified phenolic resin; and reacting the resultant modified phenolic resin with the phenols at a temperature higher than 120.degree. C. and not more than 200.degree. C. in the presence of the acid catalyst to lower the molecular weight of the modified phenolic resin. The highly reactive low-viscosity modified phenolic resin obtained according to this process has high reactivity with epoxy resins and low resin melt viscosity. In addition, this resin can be used for producing a molding material having good moldability and considerably low moisture absorption when combined with an epoxy resin.

Abstract: A fiber-reinforced resin plate comprising a fibrous base material and a matrix bonding the fibers contained in the fibrous base material, the matrix being formed by curing a resin composition comprising a highly reactive modified phenolic resin (A) prepared by polycondensing a petroleum heavy oil or pitch, a formaldehyde polymer and a phenol in the presence of an acid catalyst to thereby prepare a modified phenolic resin and-reacting the resultant modified phenolic resin with a phenol in the presence of an acid catalyst to thereby lower the molecular weight of the modified phenolic resin, and an epoxy resin (B). Also, a prepreg and a process for producing the fiber-reinforced resin plate.

Abstract: A process for producing a highly reactive modified phenolic resin, comprising the steps of polycondensing a petroleum heavy oil or pitch, a formaldehyde polymer and a phenol in the presence of an acid catalyst to thereby prepare a modified phenolic resin; and reacting the resultant modified phenolic resin with a phenol in the presence of an acid catalyst but in the absence of a crosslinking agent such as a formaldehyde polymer to thereby lower the molecular weight of the modified phenolic resin. This highly reactive modified phenolic resin has a low number average molecular weight and a high phenol content, so that its resin melt viscosity is low and that it exhibits a markedly improved reactivity with an epoxy resin.

Abstract: A molding material useful in the fabrication of an electrical or electronic part comprises a modified phenolic resin (A), an epoxy resin (B) and a curing agent (C), said modified phenolic resin prepared by heating heavy oil or pitch and a formaldehyde in a molar ratio of formaldehyde: (oil or pitch) of from 1-15:1 in the presence of an acid catalyst, adding phenol in a molar ratio of phenol: (oil or pitch) of from 0.5-5:1 to form a modified phenolic resin, and purifying by performing in optional sequence (i) a treatment with an aliphatic or alicyclic hydrocarbon and (ii) an extraction with an aromatic hydrocarbon solvent wherein the catalyst has a solubility of 0.1 or less to remove the catalyst.

Abstract: A process for producing a modified phenolic resin comprises heating (a) petroleum heavy oil or pitch and (b) a formaldehyde polymer in a molar ratio of formaldehyde:oil or pitch of from 1 to 15:1 in the presence of an acid catalyst, adding phenol in a molar ratio of phenol:oil or pitch of from 0.5 to 5:1 to form a crude modified phenolic resin, and purifying by performing in optional sequence (i) a treatment with an aliphatic or alicyclic hydrocarbon to remove unreacted components and (ii) an extraction with a solvent wherein the catalyst has a solubility of 0.1 or less to remove the catalyst.