Arakawa Chemical Industries, Ltd.

Yoshimasa Sato

Yasushi Funakoshi

Takashi Nakatani

Hideharu Takeuchi

Naoki Kamatani

Kouji Takahashi

Kohei Hatakeda

Tetsuya Kashihara

Kensuke Hikichi

Yasuhiro Matsushita

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

An object of the present invention is to provide an adhesive composition that is substantially odorless and has an extremely good color and excellent adhesive properties or tack at low temperatures of about 5&#xb0; C. and in which deterioration over time caused by heat or light is suppressed. The present invention relates to an adhesive composition comprising a liquid rosin ester compound, the liquid rosin ester compound being obtained by reacting a rosin compound with a Cmonohydric alcohol compound and having a Gardner color of 1 or less, a glass transition temperature of &#x2212;20&#xb0; C. or less, a degree of esterification of 93 wt % or more, and a ratio (Y'/Y) of the total area of peaks in 16- to 22-min retention time region (Y&#x2032;) to the total area of all the peaks (Y) measured by gas chromatography under the following conditions of 200 ppm or less.

Pressure-sensitive adhesive composition and acrylic pressure-sensitive adhesive composition

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Ibaraki, Japan

Yoshimasa Sato