There are provided an active ester composition that has high curability and that provides a cured product exhibiting excellent performance, such as in dielectric characteristics and heat resistance; a cured product of the composition; and a semiconductor sealing material and a printed wiring board that are formed from the composition. Specifically, an active ester composition containing an active ester compound and a benzoxazine compound as essential components is provided. Because the active ester composition containing the active ester compound and the benzoxazine compound as essential components is characterized by having high curability with a curing agent and providing a cured product exhibiting excellent performance, such as in dielectric characteristics and heat resistance, the active ester composition is suitable for use as a resin material for semiconductor sealing materials and printed wiring boards.

An improved photoimageable dry film formulation, a fluidic ejection head containing a thick film layer derived from the improved photoimageable dry film formulation, and a method for making a fluidic ejection head. The improved photoimageable dry film formulation includes a multifunctional epoxy compound, a photoinitiator capable of generating a cation, a non-photoreactive solvent, and from about 0.5 to about 5% by weight a silane oligomer adhesion enhancer based on a total weight of the photoimageable dry film formulation before drying.

A resin composition including a main agent containing an epoxy compound, a curing agent, and inorganic particles, the curing agent includes an aromatic compound in which a ratio of the number of carbon atoms constituting an aromatic ring to a total number of carbon atoms in one molecule is 85% or more, a content of the inorganic particles is 40 to 75 vol % based on a total amount of components other than a solvent, the inorganic particles include boron nitride particles and particles different from the boron nitride particles, and a content of the boron nitride particles is 3 to 35 vol % based on a total amount of components other than a solvent.

The purpose of the present invention is to provide an epoxy resin composition which has excellent viscosity stability, and when cured, can provide a resin cured product which has high flame retardancy and excellent mechanical properties, and a prepreg and fiber-reinforced composite material using the epoxy resin composition. An embodiment of the epoxy resin composition according to the present invention which achieves the purpose contains all components [A]-[C]. [A]: A reactive diluent having a specific structure and a viscosity of 2 Pa.Math.s or less at 25 C. [B]: An epoxy resin having three of more functional groups. [C]: An amine-based curing agent having a specific structure.

A Formula of a phosphorous fire-retardant hardener having fire-retardant and heat-resistant properties as well as a low-dielectric constant. With a preparation of glass-fiber laminated board, the hardener meets UL-94V fire-retardant requirements and has a dielectric constant 5 of 4.0 (1 GHz).

Embodiments described herein are directed to oligomeric phosphonates and polyphosphonates that have non-reactive end groups, methods for making such oligomeric phosphonates and polyphosphonates, and compositions containing such oligomeric phosphonates and polyphosphonates. The oligomeric phosphonates and polyphosphonates of such embodiments may be incorporated into engineering polymeric into which they are mixed to make polymer compositions having good flame retardancy and mechanical properties.

A low-k, non-flammable dicyclopentdiene (DCPD)-derived polyether and a method of producing the same are introduced. Incorporation of a phosphorus group and a DCPD derivative into a low-k, non-flammable dicyclopentdiene (DCPD)-derived polyether enable the DCPD-derived polyether to not only serve as an epoxy resin curing agent but also cure itself such that the cured product not only features satisfactory thermal properties and low-k characteristics but is also non-flammable.

The present teachings contemplate a method that includes a step of providing a first amount of esterified reaction product of an acid and an epoxy-based material. The esterified reaction product may be further reacted an epoxy resin to form a polymeric epoxy. The resulting material may have a generally linear backbone, foaming and curing capability and flame retardant properties.

A tablet form of an epoxy resin composition for encapsulation of semiconductor elements, where the tablet form of the epoxy resin composition: (i) includes 97 wt % or more of tablets having a diameter of 0.1 mm to less than 2.8 mm and a height of 0.1 mm to less than 2.8 mm, as measured using an ASTM standard sieve; (ii) satisfies the following Equation 1,

[00001]$\frac{.Math..Math.D.Math..Math.H}{.Math..Math.D+.Math..Math.H}1.0,$

where D is a standard deviation of tablet diameters and H is a standard deviation of tablet heights, as measured with respect to 50 tablets arbitrarily selected from the tablets; and (iii) the tablets have a compression density of 1.2 g/mL to 1.7 g/mL.

The present invention discloses a halogen-free epoxy resin composition having low dielectric loss, comprises: (A) 100 parts by weight of an epoxy resin; (B) 10-30 parts by weight of a DOPO modified curing agent; (C) 1-10 parts by weight of benzoxazine resin; (D) 60-90 parts by weight of an active ester compound; (E) 20-50 parts by weight of a flame retardant; and (F) 0.5-10 parts by weight of a curing accelerator. The halogen-free epoxy resin composition uses active ester as a curing agent of the epoxy resin to ensure that the hardening product has characteristics such as low dielectric constant (Dk), low dielectric loss (Df), high heat resistance, low water absorption, flame retardant and halogen-free. The halogen-free epoxy resin composition of the present invention is used for manufacturing semi-cured prepregs or resin-coated films, and is applied toward manufacturing metal clad laminates and printed circuit boards.