Abstract: A self-dispersing curable epoxy composition is prepared upon contacting an epoxy resin with a polyoxyalkyleneamine having a molecular weight of from about 3,000 to about 15,000 in a ratio of about 0.001 to 0.060 reactive equivalents of polyoxyalkyleneamine to about 1.0 reactive equivalents of epoxy resin. The self-dispersing curable epoxy resin forms an aqueous dispersion upon mixing with water. When cured, the dispersion is useful as a coating composition.

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.

Abstract: In a process for the production of a flame-resistant, pourable, latently reactive, phenolically curable epoxy resin molding material for the encapsulating of electronic components, a latently reactive prepolymer epoxy resin mixture in powder form which is free of isocyanate groups is produced at reaction temperatures up to 200° C. from a thermally polymerizable, filler-containing reaction resin mixture of polyepoxy resin consisting of a mixture of bi-functional and multi-functional epoxy resins and polyisocyanate resin having a molar ratio of the epoxy groups to the isocyanate groups of >1:1 with a substituted imidazole as reaction accelerator in a concentration of 0.5 to 2.5% by weight, relative to polyepoxy resin, and the prepolymer epoxy resin mixture is mixed with a powdered filler-containing phenolic resin mixture in a molar ratio of the epoxy groups to the phenolic hydroxyl groups of 1:0.4 to 1:1.1.

Abstract: A latent curing agent is disclosed for epoxy resin, comprising a reaction product obtainable by allowing (A) an epoxy compound having more than one epoxy groups on the average in the molecule and (B) a compound having in the molecule both a tertiary amino group and at least one functional group selected from the group consisting of OH group, SH group, NH group, NH2 group, COOH group and CONHNH2 group, to react on each other in the presence of 0.05-5.0 equivalents of water per 1 equivalent of the epoxy group of Compound (A); and a curable epoxy resin composition comprising such curing agent and an epoxy compound having more than one epoxy group on the average in the molecule.

Abstract: Heat sensitive substrates, as well as others such as metal or glass, are electrostatically coated with a thermosetting coating powder comprising a melt-mixed, chilled, chipped, and powdered blend of an epoxy resin and a catalyst therefore, and a polyamine as a powdered low temperature curing agent along with a scavenger which will react secondarily with residual polyamine domains that do not contact the base epoxy resin during curing. The coating powder is deposited on the substrate and heated to fuse, flow and cure. The mixture of resin and catalyst does not cure within the extruder but it is made to cure at low temperatures on the desired substrate by the separate addition of the curing agent to the powdered melt-mixed blend.

Abstract: Disclosed in a halogen-free flame-retardant epoxy resin composition, comprising (A) a bisphenol A type epoxy resin, (B) a novolak type epoxy resin, (C) a phenolic resin type curing agent, (D) a curing accelerator, and (E) an inorganic filler. The phenolic resin type curing agent (C) is provided by a nitrogen-containing phenolic resin, preferably, by a co-condensation resin formed by the reaction among a phenolic compound, a guanamine compound, and an aldehyde compound. More desirably, a phenolic resin containing both phosphorus and nitrogen should be used as the curing agent (C). Further, a combination of the co-condensation resin noted above (C-1) and a reactive phosphoric acid ester can be used as a curing agent.

Abstract: A rational technical process for producing dialkylnaphthalenes from petroleum-derived starting materials which exist in abundance is established.

Abstract: A process for preparing a polymer composition useful as a prepreg comprises (a) melt-mixing at least one thermoplastic polymer above the glass transition temperature or melt temperature of the thermoplastic polymer with either (i) an uncured epoxy resin or (ii) an epoxy curing agent or a catalyst; (b) melt-mixing above the glass transition temperature or melt temperature of the thermoplastic polymer, the other of (i) an uncured epoxy resin or (ii) an epoxy curing agent or a catalyst to form a substantially uncured but essentially curable and/or polymerizable composition; (c) optionally forming a shaped product from the melt-mixed composition of (b); and (d) fast-curing and/or fast-polymerizing the optionally formed shaped product.

Abstract: The present invention provides an adhesive resin composition including an epoxy resin, a phenolic resin and a polycarbodiimide resin, wherein the proportion of the polycarbodiimide resin is 0.5 to 20 parts by weight per 100 parts by weight of the total of the epoxy resin and the phenolic resin, and a sealing resin composition including an epoxy resin, a phenolic resin, a polycarbodiimide resin and an inorganic filler, wherein the proportion of the polycarbodiimide resin is 0.5 to 20 parts by weight per 100 parts by weight of the total of the epoxy resin and the phenolic resin and the proportion of the inorganic filler is 60 to 95 parts by weight of the total weight of the composition. The resin compositions of the present invention are superior in heat resistance and long-term stability and, moreover, have excellent adhesivity even to new materials such as Ni alloys and the like.

Abstract: An adhesive for bonding a die of an integrated circuit chip comprises an aryl cyanate (ester) resin and/or a diepoxide resin admixed with tetrahydropyranyl-protected hydroxylmethylated phenolic resin or hydroxymethylated poly(hydroxystyrene) optionally further containing an electrically or thermally conductive filler.

Abstract: The invention provides aqueous, solvent based, and solvent-free curable coating compositions which include (A) the reaction product of epoxy resin, acid, and tertiary amine; (B) reactive diluent, and, optionally, (C) curing agent. The compositions are useful for forming cured coated substrates, that are especially suitable for food and beverage packaging.

Abstract: A modified phenolic hydroxyl-containing resin having a low free difunctional phenol content and represented by general formula (1); a solid epoxy resin having an epoxy equivalent of 450 to 2,500 g/eq and prepared by epoxidizing the above resin; and another solid epoxy resin having an epoxy equivalent of 1,500 to 60,000 g/eq and a number-average molecular weight of 3,000 to 15,000 and prepared by reacting the above epoxy resin with a difunctional phenol compound. Resin compositions containing these resins have many applications as powder coatings and can paints. In formula (1), X represents a residue of a difunctional phenol compounds; X's may be the same or different; and n is the number of repeating units and is an integer of 0 or above.

Abstract: An epoxy resin composition for semiconductor sealing, which comprises an epoxy resin, a curing agent and an inorganic filler, and has a J-value of 10 to 50, which is a maximum jetting flow value determined according to a method of evaluating jetting flow of epoxy resin composition.

Abstract: Epoxy resin compositions containing polyepoxides having at least two 1,2-epoxide groups are disclosed. The polyepoxides can be obtained by reacting (i) di- or polyepoxides or mixtures thereof with monoepoxides, (ii) one or more amines chosen from sterically hindered amines, disecondary diamines and diprimary diamines to form an epoxide-amine adduct, and (iii) subsequently reacting the epoxide-amine adduct with polyfunctional isocyanates. The composition also contains curing agents for the polyepoxides and can optionally contain additional 1,2-epoxide compounds and additives. The compositions are useful as coatings for bridging cracks, as adhesives and as constituents of paints.

Abstract: An adhesive comprising (1) 100 parts by weight of a combination of an epoxy resin having a weight average molecular weight of less than 5,000 and a curing agent, (2) 10 to 40 parts by weight of a high-molecular weight component being compatible with the epoxy resin and having a weight average molecular weight of 30,000 or above, (3) 20 to 100 parts by weight of a high-molecular weight component being incompatible with the epoxy resin and having a weight average molecular weight of 30,000 or above, and (4) 0.1 to 5 parts by weight of a cure accelerator. The adhesive is excellent not only in moisture resistance, heat resistance, adhesive strength at high temperature, heat dissipation, reliability of insulation, crack resistance and flexibility but also in circuit filling and tight adhesion, and exhibits suitable flow properties.

Abstract: A solid, one-component, flexible epoxy-based composition and method for making the same are provided. The present compositions comprise: (a) an epoxy-terminated prepolymer formed by reacting at least four moles of a polyepoxide resin with approximately one mole of a diamine compound, wherein at least one of the polyepoxide resin and diamine compound is solid at room temperature, and wherein the prepolymer is rheologically stable for weeks as a single component mixture at room temperature and, and (b) a substantially stoichiometric amount of an epoxy resin curing agent selected from the group consisting of a heat-curable, latent epoxy resin curing agent and a room temperature-curable ketimine curing agent. Optional components include thixotropic agents, diluents, fillers, anti-oxidants, and processing aids. The present uncured epoxy-based compositions upon cure, exhibit a durometer Shore D of less than about 45 (or a durometer Shore A of less than about 100).

Abstract: An adhesive for bonding a die of an integrated circuit chip comprises an aryl cyanate (ester) resin alone and/or a diepoxide resin admixed with a hydroxymethylated phenolic resin or hydroxymethylated poly(hydroxystyrene) which can further contain an electrically or thermally conductive filler.

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: Disclosed is a multilayer packaging material which is suitable for use as a container for malt beverages and which is tinted so as to block at least 90% of light with wavelengths of electromagnetic radiation ranging from 300 nm to 500 nm. The tinted multilayer packaging materials of the present invention includes: (a) at least one layer of a carbon dioxide (CO.sub.2)-permeable polymeric packaging material, and (b) at least one layer of a CO.sub.2 -treated gas barrier coating, which has an oxygen permeability constant not more than 0.05 cubic centimeter-mil/100 square inches/atmosphere/day. The CO.sub.2 -permeable packaging material can be any polymeric material through which CO.sub.2 can pass and which can be used as a packaging material for food or beverages. The gas barrier coating has an oxygen permeability constant, before CO.sub.2 treatment, of less than 0.3. This gas barrier coating includes the reaction product of a polyamine (A) and a polyepoxide (B).

Abstract: There is disclosed a self-dispersing curable epoxy resin composition comprising the addition product of reactants comprising (a) 1.0 reactive equivalent of an epoxy resin, (b) from about 0.40 to 0.95 reactive equivalents of a polyhydric phenol, and (c) from about 0.005 to 0.5 reactive equivalents of an amine-epoxy adduct comprising the addition product of reactants comprising 1.0 reactive equivalent of a polyepoxide and from about 0.3 to 0.9 reactive equivalents of a polyoxyalkyleneamine with the structural formulaH.sub.2 N--CH(R.sub.2)CH.sub.2 --O--R.sub.1 --CH.sub.2 CH(R.sub.2)--NH.sub. 2wherein:R.sub.1 represents a polyoxyalkylene chain having the structural formula:(CH.sub.2 --CH.sub.2 --O).sub.a --(CH.sub.2 --CH(R.sub.3)--O).sub.bwherein:R.sub.3 is a monovalent organic radical selected from the group consisting of C.sub.1 to C.sub.4 aliphatic hydrocarbons,`a` designates a number of ethoxy groups (CH.sub.2 --CH.sub.2 --O),`b` designates a number of monosubstituted ethoxy groups (CH.sub.2 --CH(R.sub.

Abstract: An improved oxazolidine-based hardener to be used with a resorcinol resin or a tannin resin as the adhesive for the bonding of wood articles. Preferably, an oxazolidine is combined with a base such as NaOH and a powdered absorbent such as wheat flour. The adhesive based on the improved hardener can be used to glue wood particles to pass wet strength requirements after the glue is cured at room temperature for under 24 hours. The improved hardener composition is storage stable; it can be prepared anytime before its use, thus eliminating the need to prepare a hardener immediately prior to the glue use. Since it is formaldehyde-free; it eliminates the safety issues associated with handling formaldehyde or paraformaldehyde. Also, the hardener provides flexible gel time or working time. Since the resins can be cured at room temperature, heating in an oven is not needed but could be used to reduce curing time. If radio frequencies are used to cure the resins, the exposure time can be reduced.

Abstract: A composition useful as a powder coating comprises an epoxy resin and a novolak compound or resin having a structure obtained from the reaction of a substituted phenol such as cresol and an aldehyde to form a substituted bis(hydroxymethyl) phenol intermediate which is then reacted with a polyhydroxyphenol containing adjacent hydroxyl groups such as catechol to yield a polyhydroxyphenol-endcapped novolak compound or resin.

Abstract: A coating composition is described comprising, in an aqueous medium:A) a resin having a plurality of primary amine groups, andB) a curing agent having a plurality of cyclic carbonate groups.

Abstract: The present invention relates to a low VOC solvent based adhesive comprising a mixture of at least two organic solvents and a thermoplastic resin. Desirably the adhesive has a flash point of at least 100.degree. F. when measured in accordance with ASTM D3828-87. The solvent blend of the low VOC solvent based adhesive of the instant invention volatilizes at substantially reduced rates as compared to conventional solvent blends in solvent based adhesives. Furthermore, this novel low VOC solvent based adhesive is easy to apply, cost effective, and cures within a reasonable time without the use of heat, ultraviolet light or other mechanical devices. In addition, the novel low VOC solvent based adhesive has good storage stability in metal or non-metal containers.

Abstract: A water-soluble urea-extended phenol-formaldehyde resole resin stabilized with an alkanolamine alone or combined with a monosaccharide or disaccharide, methods of manufacturing the resin and using it, and products prepared using the resin.

Abstract: A self-dispersing curable epoxy composition is prepared upon contacting (a) 1.0 reactive equivalents of an epoxy resin, (b) from about 0.01 to 1.0 reactive equivalents of a polyhydric phenol, and (c) between 0.005 and 0.025 reactive equivalents of an amine-epoxy adduct, wherein the amine-epoxy adduct is formed upon contacting 1.0 equivalents of an aliphatic polyepoxide and between 0.3 and 0.9 reactive equivalents of a polyoxyalkyleneamine. The self-dispersing curable epoxy resin forms an aqueous dispersion upon mixing with water. When cured, the dispersion is useful as a coating composition.

Abstract: Epoxy resin mixtures for prepregs and compositesEpoxy resin mixtures for preparing prepregs and composites contain the following components:a phosphorus-modified epoxy resin with an epoxy value of 0.02 to 1 mol/100 g, made up of structural units derived from(a) polyepoxy compounds with at least two epoxy groups per molecule and(b) phosphinic acid anhydrides, phosphonic acid anhydrides, or phosphonic acid half-esters;a glycidyl group-free compound with phenolic OH groups in the form of bisphenol-A, bisphenol-F, or a high-molecular phenoxy resin obtained through the condensation of bisphenol-A or bisphenol-F with epichlorohydrin;an aromatic polyamine used as a hardening agent.

Abstract: A binder solution of a phenolic novolak resin in solvent, preferably furfuryl alcohol containing at least one chemical agent such as amines containing one to five, preferably two to four, nitrogen atoms, glycerine or mixtures thereof. Preferably, the binder solution contains about 0.2 to about 1.5 weight percent water. The binder solution is for binding refractory objects, preferably those containing doloma (calcined dolomite) aggregate. Methods of mixing these ingredients and using the mixture are also disclosed. Bricks made from the doloma aggregate mixed with the binder solution show good ambient temperature green strength and enhanced modulus of rupture after curing and coking.

Abstract: The invention relates to an organic phosphorus compound-containing which comprises an interpenetrating polymer network (IPN) produced by polymerizing free-radically polymerizable monomers comprising at least an allyl group-containing monomer and an epoxy resin.

Abstract: Disclosed is a multilayer packaging material which is suitable for use as a container for malt beverages and which is tinted so as to block at least 90% of light with wavelengths of electromagnetic radiation ranging from 300 nm to 500 nm. The tinted multilayer packaging materials of the present invention includes: (a) at least one layer of a carbon dioxide (CO.sub.2)-permeable polymeric packaging material, and (b) at least one layer of a CO.sub.2 -treated gas barrier coating, which has an oxygen permeability constant not more than 0.05 cubic centimeter-mil/100 square inches/atmosphere/day. The CO.sub.2 -permeable packaging material can be any polymeric material through which CO.sub.2 can pass and which can be used as a packaging material for food or beverages. The gas barrier coating has an oxygen permeability constant, before CO.sub.2 treatment, of less than 0.3. This gas barrier coating includes the reaction product of a polyamine (A) and a polyepoxide (B).

Abstract: A resin composition useful as a binder is provided comprising a mixture of a formaldehyde-based resin with a resin substitute comprising the reaction product of an amine derivative chosen from melamine, glycolurile or their mixtures with 1 to 2 moles of a C.sub.1 to C.sub.8 dialkoxyethanal, the reaction product is mixed, preferably reacted, with a polyol.

Abstract: Cyclic acetal derivative of a resole includes the reaction product of an ortho resole compound with a carbonyl compound or a carbonyl compound derivative. The cyclic acetal derivatives of phenolic resole compounds exhibit enhanced storage stability and can be readily activated at elevated temperatures to prepare phenolic based adhesives and coatings.

Abstract: A resin composition for a laminate comprises 100 parts by weight of a polyfunctional epoxy resin (I) obtained by (i)(1) glycidylizing a polycomposite formed from a blend of brominated bisphenol A and bisphenol A, or brominated bisphenol A and formaldehyde; or (2) a mixture of a polyfunctional epoxy resin and a bisphenol A-advanced epoxy resin reacted with brominated bisphenol A in a hydroxyl:epoxy equivalent ratio of from 0.05-0.5:1 and (ii) a bisphenol A-formaldehyde phenolic resin having a weight average molecular weight of from 1,000-10,000 in a hydroxyl:epoxy equivalent ratio with respect to epoxy resin (i) of from 0.7-1.2:1; and (II) from 1-60 parts by weight of a straight chain polymer (c) such as a poly(ether)sulfone, aromatic polyester, phenoxy resin, polyparabanic acid, polyetherimide or polyphenylene sulfide.

Abstract: The present invention provides novel thermoset copolymers, and methods for preparing same, having both the strength and the thermo-oxidative stability required for high performance, high temperature applications. The copolymers comprise (a) a thermoplastic resin having unreacted phenolic OH groups, and (b) bis-oxazoline monomers which have been modified to have at least one substituent on the oxazoline ring selected from the group consisting of a methyl group, a group having at least a substituent capable of undergoing addition polymerization, and a cyclic group capable of undergoing ring opening polymerization.

Abstract: An epoxy resin composition for semiconductor encapsulation use comprising an epoxy resin, a phenol resin, and an inorganic filler is improved by blending therein a component which is obtained by copolymerizing or homopolymerizing a reactive monomer having a vinyl group and an epoxy or phenolic hydroxyl group in a molecule thereof with or preferably in the presence of a thermoplastic elastomer or organic synthetic rubber. Alternatively, the modifying component (C) is obtained by copolymerizing a reactive monomer and a silane monomer with or preferably in the presence of a thermoplastic elastomer or organic synthetic rubber. The composition cures to products having improved thermal shock resistance and adherence.

Abstract: A curable coating composition is described comprising two components that are reactive with one another upon curing to form urethane linkages. The urethane-forming components are an active hydrogen groups-containing component and a polyisocyanate, or a carbamate groups-containing component and a carbamate group-reactive component. The composition further comprises a third component that includes one or more epoxide groups. Coatings prepared with this coating composition can be cured and coated with additional coating(s), providing good intercoat adhesion to the subsequent coating.

Abstract: An epoxy resin composition is disclosed that contains compounds that contain at least two 1,2-epoxide groups. The epoxide group-containing compounds are reaction products of compounds (A1) that contain at least two 1,2-epoxide groups per molecule, compounds (A2) that are polyoxyalkylenemonoamines that have a molecular weight of from 130 to 900 and, if desired, polyoxyalkylenemonoamines (A3) that have a molecular weight of from 900 to 5000 and/or polycarboxylic acids (A4). The resin composition additionally contains at least one hardener (B) and, if desired, customary additives (C).

Abstract: An epoxy resin composition is disclosed that contains compounds that contain at least two 1,2-epoxide groups. The epoxide group-containing compounds are reaction products of compounds (A1) that contain at least two 1,2-epoxide groups per molecule, compounds (A2) that are polyoxyalkylenemonoamines that have a molecular weight of from 130 to 900 and, if desired, polyoxyalkylenemonoamines (A3) that have a molecular weight of from 900 to 5000 and/or polycarboxylic acids (A4). The resin composition additionally contains at least one hardener (B) and, if desired, customary additives (C).

Abstract: This invention is a two-part induction-curable epoxy adhesive comprising a first part of a polyfunctional epoxy such as a sorbitol polyglycidyl ether, and a diepoxy compound such as a diepoxy bisphenol-A wherein a portion of the diepoxy compound may preferably comprise a glycol-based epoxy having an epoxy equivalent weight of at least about 250. The second part of the adhesive is a curing agent which preferably maybe a mixture of nitrogen-based compounds di(aminoalkyl)ether of diethylene glycol, and a toughening agent. The invention also comprises a method of adjoining two substrates by applying the adhesive composition of the invention and curing as well as the article resulting from this method.

Abstract: Polyethylene naphthalate pellets coated with an alkylene carbonate such as ethylene carbonate or propylene carbonate crystallize more quickly and at lower temperature than uncoated pellets, reducing the tendency of the pellets to stick together during the crystallization process prior to solid-state polymerization.

Abstract: The present invention relates to a curable mixture which is useful in the formation of castings and which contains (a) an epoxy resin and (b) a mixture of oligomeric cyanoguanidines obtained by the reaction between a monoisocyanate and a diisocyanate to give a carbodiimide which is subsequently reacted with cyanamide.

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: The present invention provides polyhydric phenols which are starting materials for glycidyl ether compounds which can provide cured products having low moisture absorption, high heat resistance and improved crack resistance and can be used for encapsulating semiconductor devices. The polyhydric phenols are represented by the following formula: ##STR1## wherein R.sup.1 independently represents a halogen atom, an alkyl or cycloalkyl group of 1-9 carbon atoms, an alkoxy group of 4 or less carbon atoms or an aryl group and R.sup.1 may be identical or different when l is 2 or more, R.sup.2 independently represents a halogen atom, an alkoxy group of 4 or less carbon atoms or an alkyl group of 6 or less carbon atoms and R.sup.2 may be identical or different when m is 2 or more, R.sup.

Abstract: A self-curing cationically electrodepositable resin useful as a paint composition having in the molecule:(1) a primary hydroxyl group,(2) a cationic group, and(3) at least one epoxy group-containing functional group represented by the following structural formulas (I) and (II): ##STR1## The electrodepositable resin is obtained by the reaction of an epoxy resin with at least three epoxy group-containing functional groups of structural formulas (I) and (II), a cationizing agent such as amino compounds, and a compound having at least one phenolic hydroxyl group per molecule.

Abstract: An epoxy resin composition having high epoxy curing property and sufficient storage stability, and an epoxy curing agent therefor. The curing agent or the cure accelerating agent obtained by treating the surfaces of (1) an epoxy adduct obtained by adding a nitrogen-containing heterocyclic compound, an aliphatic amine or an aromatic amine to an epoxy compound having one, two or more epoxy groups in one molecule, with (2) a boric acid compound or (3) a boric acid compound and a phenolic compound, exhibits high curing property and storage stability, and can be favorably used as a curing agent for the epoxy resin composition. The epoxy resin composition prepared by mixing the epoxy resin with (1) and (2) or (1) and (3), exhibits excellent curing property and storage stability.

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.

Abstract: The present invention relates to a modified epoxy resin, a method for the preparation thereof and an epoxy resin composition using the modified epoxy resin. In particular, it relates to a modified epoxy resin of the general formula (I) which is prepared by incorporating a monomaleimide having a carboxy group useful as a heat resistance-improving agent of a resin composition containing an epoxy resin and maleimides into an epoxy resin, and an epoxy resin composition for sealing a semiconductor element having the improved heat resistance and moldability by the modified epoxy resin. ##STR1## wherein, R represents a hydrogen atom or an alkyl group having from 1 to 10 carbon atoms (C.sub.1 to C.sub.10), andn is 0 to 100, and m is 1 to 100.

Abstract: Oligomeric cyanoguanidines of formula I ##STR1## wherein, for example, R.sup.1 and R.sup.2 are each phenyl, R is 1,4-phenylene and n is an integer from 1 to 20, are suitable latent hardeners for epoxy resins. They are readily soluble in solvents suitable for the application of epoxy resins, and the cured products obtained therewith have a high glass transition temperature.

Abstract: A resinous material for the manufacture of printed circuit boards is obtained by (a) treating a mixture of bromine- and nonbromine-containing epoxy resins with a secondary diamine such as 5,5-dimethyl hydantion or barbituric acid in the presence of a tertiary amine catalyst to form a modified epoxy resin; (b) heating the modified epoxy resin and a polyisocyanate in the presence of an encyclization catalyst; and (c) dissolving the resulting product in a solvent with a curing agent to form a B-stage prepreg varnish.

Abstract: An epoxy resin composition contains an epoxy resin represented by the formula (I) and a curing accelerator: ##STR1## wherein R.sup.1 stands for ##STR2## where G stands for a glycidyl group, R.sup.2 stands for an alkyl group having 1 to 4 carbon atoms, R.sup.3 and R.sup.4 stand for the same or different groups and each denote a hydrogen atom or a glycidyl group, m and x each denote an integer of 0 to 10, n denotes an integer of 0 to 2, provided that m.gtoreq.x and, if m=0, then x=0, in which case at least one of R.sup.3 and R.sup.4 denotes a glycidyl group on the condition that when m.gtoreq.1 and m>x, R.sup.1 may each stand for different groups.