Provided are a phenoxy resin having excellent heat resistance, low hygroscopicity, and solvent solubility, a resin composition using the same, and a cured object obtained therefrom. The phenoxy resin is represented by Formula (1) below and has an Mw of 10,000 to 200,000: ##STR00001##
where, X represents a divalent group, and includes, essentially, a group having a cyclohexane ring structure and a group having a fluorene ring structure. Y represents a hydrogen atom or a glycidyl group. n is the number of repetitions and an average value thereof is 25 to 500.

A prepreg includes a resin composition or a semi-cured product of the resin composition, and a glass cloth, wherein the resin composition contains a modified polyphenylene ether compound terminally modified with a substituent having an unsaturated carbon-carbon double bond, and a crosslinkable curing agent having an unsaturated carbon-carbon double bond in a molecule, a content of the modified polyphenylene ether compound is 40 to 90 mass % with respect to a total mass of the modified polyphenylene ether compound and the crosslinkable curing agent, a cured product of the resin composition has a relative permittivity of 2.6 to 3.8, the glass cloth has a relative permittivity of 4.7 or less and a dielectric loss tangent of 0.0033 or less, and a cured product of the prepreg has a relative permittivity of 2.7 to 3.8 and a dielectric loss tangent of 0.002 or less.

Provided are a phenoxy resin having excellent heat resistance, low hygroscopicity, and solvent solubility, a resin composition using the same, and a cured object obtained therefrom. The phenoxy resin is represented by Formula (1) below and has an Mw of 10,000 to 200,000:

##STR00001##

where, X represents a divalent group, and includes, essentially, a group having a cyclohexane ring structure and a group having a fluorene ring structure. Y represents a hydrogen atom or a glycidyl group. n is the number of repetitions and an average value thereof is 25 to 500.

The present disclosure provides a low dielectric resin composition having good melt processability and excellent low dielectric characteristics in a high frequency band as compared to low dielectric materials such as liquid crystal polymers. A molded article and a film, each of which is formed from the low dielectric resin composition, a multilayer film obtained by superposing a metal foil on at least one main surface of the film, and a flexible printed wiring board which includes the film are also provided. The present disclosure includes, as a low dielectric resin composition, a resin composition which contains (A) a liquid crystal polymer and (B) a graft-modified polyolefin having a polar group. The low dielectric resin composition has a dielectric constant of 2.80 or less at a frequency of 10 GHz and a dielectric loss tangent of 0.0025 or less at a frequency of 10 GHz.

Disclosed is a method for producing a semiconductor device including a circuit board having a flexible resin layer that encapsulates a circuit component. The method may include a step of immersing a flexible substrate in an encapsulant, drying the encapsulant, and thereby encapsulating the circuit component with the encapsulant; and a step of curing the encapsulant, and thereby forming a flexible resin layer.

An inductor bridge includes a flexible substrate and a coil defined by a conductor pattern provided on or in the flexible substrate, and connects a plurality of circuit portions. The flexible substrate includes a rigid portion and a flexible portion, the rigid portion being wider than the flexible portion. The rigid portion includes the coil and a joining portion connected to another circuit. The coil includes two coil portions located at different positions in plan view, a flexible portion is located adjacent to one side of the rigid portion, and at least two coil portions of the plurality of coil portions are located on the one side when viewed from the joining portion.

This room-temperature-curable polybutadiene resin composition contains: (A) a urethane oligomer comprising a condensation polymer of (A1) a polybutadiene having an OH group at both ends of the molecular chain and (A2) a diisocyanate compound; (B) a hydrolysable organosilane compound which, in one molecule, has on average two or more hydrolysable groups bonded to a silicon atom and does not have three or more nitrogen atoms, and/or a partially hydrolysed condensate of said compound; (C) a condensation reaction catalyst; and (D) a hydrolysable organosilane compound which, in one molecule, has three or more nitrogen atoms, and/or a partially hydrolysed condensate of said compound.

Said room-temperature-curable polybutadiene resin composition allows a coating film to be obtained, in particular a coating film that is resistant to gas permeation, said coating film therefore being useful as a coating material having properties preventing corrosion by a corrosive gas.

The present application provides a circuit material and a circuit board containing the same. The circuit material comprises a conductive metal layer and a dielectric substrate layer, and an adhesive layer arranged therebetween, wherein the adhesive layer is made of a material which comprises an adhesive composition comprising a resin component and a non-resin component, wherein the resin component is composed of unsaturated polyphenylene ether resin, SBS resin and maleimide resin; and the non-resin component comprises an initiator; and the adhesive layer is obtained by applying the adhesive composition dissolved in a solvent onto the surface of the conductive metal layer or the dielectric substrate layer in the form of a solution, or by applying to a release material and removing the release material after partially curing or completely curing.

A laminated uncured sheet of the present disclosure has a structure in which resin sheet layers and resin layers are alternately laminated and a through hole penetrating in the laminating direction is formed, wherein the resin sheet layers are formed with a thermosetting resin composition containing a thermosetting resin as a main component, the resin layers are formed with a thermoplastic resin composition containing a thermoplastic resin, and the thermoplastic resin composition is adhered to the inner wall surface of the resin sheet layer part in the through hole.

A polyphenylene ether resin composition includes a modified polyphenylene ether copolymer, a high-molecular-weight compound, and a crosslinking agent for the modified polyphenylene ether copolymer. The modified polyphenylene ether copolymer includes a substituent having a carbon-carbon unsaturated double bond at a molecular chain end of the modified polyphenylene ether copolymer. The high-molecular-weight compound has a glass transition temperature (Tg) measured by differential scanning calorimetry of 20° C. or lower and has a number-average molecular weight Mn ranging from 1000 to 10000, inclusive. The crosslinking agent includes at least two carbon-carbon unsaturated double bonds per molecule, and includes at least one of dicyclopentadiene acrylate and dicyclopentadiene methacrylate. In a cured state of the polyphenylene ether resin composition, the modified polyphenylene ether copolymer is phase separated from the high-molecular-weight compound.