Arakawa Chemical Industries, Ltd.

Hideharu Takeuchi

Masaki Kobayashi

Yoshimasa Sato

Naoki Kamatani

Kouji Takahashi

Kohei Hatakeda

Kouki Hamata

Minoru Murata

Takahiro Koshimizu

A polymerized rosin compound includes a rosin dimer component (A) including a bifunctional rosin dimer component (a1) represented by formula (1): ROOC&#x2014;X&#x2014;COOR. In this formula, X represents a rosin dimer residue derived from abietic acid, neoabietic acid, or palustric acid, which are resin acids having conjugated double bonds; and R represents hydrogen, an alkyl group of I to 5 carbon atoms, or a benzyl group. The rosin dimer component (A) contains a bifunctional rosin dimer component (a1) in the amount of 80% by weight or more and a rosin trimer or higher oligomer component (B) in the range from 1.5 to 3.7% by weight, wherein the rosin dimer component is free of a monofunctional rosin dimer component (a2) having one functional group represented by formula (2): ROOC&#x2014;, wherein R represents hydrogen, an alkyl group of 1 to 5 carbon atoms, or a benzyl group, and free from functional group containing rosin dimer component (a3), wherein the functional group represented by formula (2): ROOC&#x2014;, wherein R represents hydrogen, an alkyl group of 1 to 5 carbon atoms, or a benzyl group. The polymerized rosin compound contains a large amount of the bifunctional rosin dimer component that makes it possible to obtain linear polymer with a high molecular weight.

Polymerized rosin compound and production method therefor

The present invention provides an optical semiconductor encapsulating composition comprising (A) an epoxy compound, (B) a carboxylic anhydride curing agent, (C) a curing accelerator, and (D) surface-coated silica particles having an average particle diameter of 5 to 50 nm in which 0.2 to 3 mmol of a silane coupling agent (D2) that contains an epoxy group-containing silane coupling agent (d1) is reacted with 1 g of silica particles (D1) to surface-coat the silica particles, the epoxy group being converted into a hydroxyl group through ring opening; and an optical semiconductor device in which an optical semiconductor is encapsulated with the composition.

Optical semiconductor-sealing composition

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Ibaraki, Japan

Hideharu Takeuchi