Abstract: This invention provides a modified liquid epoxy resin having a low viscosity and a high performance, which is obtained by reacting a mixture of a bisphenol and a phenol aralkyl resin with an epiholohydrin. The bisphenol is preferable to be bisphenol F and is further preferable to have a bifunctional form purity as detected by gel permeation chromatography at UV 254 nm of not less than 95% by area in view of the fluidity. Moreover, the mixture of bisphenol and the phenol aralkyl resin is preferable to have a ratio of the phenol aralkyl resin of 10-70% by mass.

Abstract: A phenolic compound which can be obtained by reacting the compound of the formula (1): wherein R1 groups are each independently present and represent a hydrogen atom etc. with the formula (6): wherein R4 groups are each independently present and represent a hydrogen atom etc.; and k represents the number of R4 groups and is an integer of 0 to 4 and an epoxy resin which can be obtained by reacting the phenolic compound with an epihalohydrin are excellent in solvent solubility and also of which cured product has an excellent thermal conductance.

Abstract: Disclosed is a phenol aralkyl epoxy resin having a structure wherein at least a phenol or a naphthol is bound by using an aralkyl group as a linking group and a structure represented by formula (1) below, while satisfying the condition 1 below. This epoxy resin is excellent in workability during production of a composition and is easy to control quality. Condition 1: The following relation (?) is satisfied with A being the hydroxyl equivalent (as measured in accordance with JIS K 0070) of a phenol-modified epoxy resin obtained by adding an equivalent molar amount of phenol relative to the epoxy equivalent of the epoxy resin, and B being the epoxy equivalent of the epoxy resin. 50?1000×(A?B)/B?250 (?).

Abstract: A phenol aralkyl type phenolic resin represented by the general formula (1), wherein the total content of the compounds represented by formulae (2) to (4) is 58 to 92% as determined by GPC and the contents of the compounds represented by formulae (2) to (4) as determined by HPLC satisfy the following relationship: 0.60?(2a+b)/(2a+2b+2c)?0.90 wherein a is the content of the compound of formula (2); b is the content of the compound of formula (3); and c is the content of the compound of formula (4).

Abstract: To provide an epoxy resin giving a cured object having high heat resistance, which is improved in impact resistance and moisture resistance as compared with conventional high-heat-resistance epoxy resins. The epoxy resin is obtained by glycidylating one or more phenol compounds comprising 95% or more 1,1,2,2-tetrakis (hydroxyphenyl)ethane, and is characterized in that in an examination by gel permeation chromatography, the epoxy resin has a tetranucleus-form content of 50 to 90% by area and an octanucleus-form content of at least 5% by area and has a total chlorine content of 5,000 ppm or smaller.

Abstract: This invention provides a modified liquid epoxy resin having a low viscosity and a high performance, which is obtained by reacting a mixture of a bisphenol and a phenol aralkyl resin with an epiholohydrin. The bisphenol is preferable to be bisphenol F and is further preferable to have a bifunctional form purity as detected by gel permeation chromatography at UV 254 nm of not less than 95% by area in view of the fluidity. Moreover, the mixture of bisphenol and the phenol aralkyl resin is preferable to have a ratio of the phenol aralkyl resin of 10-70% by mass.

Abstract: A phenol aralkyl type phenolic resin represented by the general formula (1), wherein the total content of the compounds represented by formulae (2) to (4) is 58 to 92% as determined by GPC and the contents of the compounds represented by formulae (2) to (4) as determined by HPLC satisfy the following relationship: 0.60?(2a+b)/(2a+2b+2c)?0.90 wherein a is the content of the compound of formula (2); b is the content of the compound of formula (3); and c is the content of the compound of formula (4).

Abstract: [Problems] To provide an epoxy resin giving a cured object having high heat resistance, which is improved in impact resistance and moisture resistance as compared with conventional high-heat-resistance epoxy resins. [Means for Solving Problems] The epoxy resin is obtained by glycidylating one or more phenol compounds comprising 95% or more 1,1,2,2-tetrakis(hydroxyphenyl)ethane, and is characterized in that in an examination by gel permeation chromatography, the epoxy resin has a tetranucleus-form content of 50 to 90% by area and an octanucleus-form content of at least 5% by area and has a total chlorine content of 5,000 ppm or smaller.

Abstract: Disclosed is a phenol aralkyl epoxy resin having a structure wherein at least a phenol or a naphthol is bound by using an aralkyl group as a linking group and a structure represented by formula (1) below, while satisfying the condition 1 below. This epoxy resin is excellent in workability during production of a composition and is easy to control quality. Condition 1: The following relation (?) is satisfied with A being the hydroxyl equivalent (as measured in accordance with JIS K 0070) of a phenol-modified epoxy resin obtained by adding an equivalent molar amount of phenol relative to the epoxy equivalent of the epoxy resin, and B being the epoxy equivalent of the epoxy resin.

Abstract: The present invention relates to a sealant for liquid crystals having extremely low contamination nature to a liquid crystal, excellent coatability and bondability to a substrate, long service life and pot life and high adhesive strength. A sealant for liquid crystals of the present invention is characterized by comprising (a) an epoxy resin represented by general formula (1): (wherein a represents an integer of 2 to 4; n represents 0 to 3 (average value); R represents a divalent hydrocarbon group of 2 to 6 carbon atoms; A represents a polyvalent aromatic group; and G represents a glycidyl group, provided that when n is 0, (a) an epoxy resin represented by general formula (1) is a bisphenol S-type.), (b) a thermo-curing agent, (c) and a filler having average particle diameter of not larger than 3 ?m.

Abstract: An object of the present invention is to provide an epoxy resin exhibiting superior heat resistance, dielectric properties, water resistance, and workability, a resin composition containing the epoxy resin, and a prepreg and a laminated plate. The epoxy resin of the invention is expressed by the following formula. (In the formula, R represents a hydrocarbon group having a carbon number of 1 to 4. m Represents an integer of 1 to 4 and when m is 2 to 4, R's may be the same or different. n Represents a positive number of 1 to 6 on average.) The epoxy resin composition of the invention contains the epoxy resin of the invention and a curing agent.

Abstract: It is an object of the present invention, with respect to a phenol aralkyl type epoxy resin, to suppress any crystal precipitation, improve the quality manageability and operation efficiency at composition production and enhance the properties, including heat resistance, thereof. It is also intended to provide a resin composition that even when stored in the form of a varnish for a prolonged period of time, is resistant to crystal precipitation, excelling in storage stability and operation efficiency, and that gives a hardening product of low dielectric constant and low dielectric tangent excelling in heat resistance, water resistance and flame retardance. There is provided an epoxy resin characterized by comprising a phenol aralkyl type epoxy resin in which a content (an area % measured by gel permeation chromatography) of a bifunctional compound is 20% or less, and provided a resin composition obtained therefrom.

Abstract: An object of the present invention is to provide an epoxy resin that can be easily produced, can easily achieve a molecule-aligned state, and can be cured to provide a cured material with optical anisotropy and excellent toughness and thermal conductivity. The epoxy resin of the present invention is represented by the following formula (1): (wherein n is 0.1 to 20 (the number is an average). The epoxy resin of the present invention can be produced by extending the chain of an epoxide of 4,4?-bisphenol F with 4,4?-biphenol.

Abstract: Disclosed is an epoxy resin composition for optical semiconductor encapsulation which contains an epoxy resin obtained by co-hydrolysis/condensation of alkoxy silicon compounds expressed as XSi(R1)n(OR2)3-n (wherein X represents an organic group having an epoxy group; R1 represents a substituted or unsubstituted alkyl group having 1-10 carbon atoms, a substituted or unsubstituted aryl group or a substituted or unsubstituted alkenyl group having 2-5 carbon atoms; R2 represents an alkyl group having 1-4 carbon atoms; n represents an integer of 0-2; and when more than one R1 are included, they may be the same as or different from each other) or co-hydrolysis/condensation of such an alkoxy silicon compound and another specific alkoxy silicon compound.

Abstract: An epoxy resin represented by formula (1) below: wherein the ratio of the component having two nuclei accounting for 25% or less in terms of the area corresponding to the component in a gel permeation chromatogram.

Abstract: The present invention relates to an epoxy resin whose cured product has a high heat resistance, and directed to provide an epoxy resin improved in adhesiveness and toughness in comparison with the conventional highly heat resistant epoxy resin. Specifically disclosed is an epoxy resin obtainable by glycidylation of a mixture of (a) a phenol compound condensate which is a condensate of phenols and glyoxal and contains not less than 80% (area % by a gel permeation chromatography) of a compound represented by the formula (1): (wherein R represents each independently a hydrogen atom, (C1-C15) hydrocarbon group or trifluoromethyl group); and (b) a phenol compound other than (a) or a phenol resin.

Abstract: The object of the present invention is to provide an epoxy resin and epoxy resin composition having a low viscosity which can afford a cured product having an excellent heat resistance. The present invention is characterized by using an epoxy resin which is obtained by reacting 5-methylresorcin with epihalohydrin in the presence of alkali metal hydroxide.

Abstract: An object of the present invention is to provide an epoxy resin composition which has high flexibility, can be molded to a thin membrane, and can become a noninflammable cured product.

Abstract: An object of the present invention is to provide an epoxy resin composition which has high flexibility, can be molded to a thin membrane, and can become a noninflammable cured product. The present invention comprises a polyphenol compound obtained by reacting to condense phenol with bischloromethyl biphenyl or bismethoxymethyl biphenyl, removing unreacted phenol and then reacting with BCMB again, wherein the polyphenol compound has a weight-average molecular weight of 3,000 or more as determined by GPC, and using the polyphenol compound as an agent for curing an epoxy resin.

Abstract: The object of the present invention is to provide an epoxy resin and epoxy resin composition having a low viscosity which can afford a cured product having an excellent heat resistance. The present invention is characterized by using an epoxy resin which is obtained by reacting 5-methylresorcin with epihalohydrin in the presence of alkali metal hydroxide.