Kao Corporation

Takanobu Shiroishi

Hiromichi Takahashi

Yoshitaka Miyauchi

Yoichi Ishibashi

Yoshinao Kono

Koji Hamaguchi

Daisuke Shiba

Hideaki Urushibata

Deinking agent represented by the following formula (I):

Deinking agent with polyoxyalkylene group consisting of specific block

The present invention aims at developing a deinking method applicable to the deinking of, for example, waste OA (office automation) paper and telephone directories, whereby a deinked pulp having a high whiteness and little contamination with large ink spots and unliberated ink can be obtained. The object of the present invention can be achieved by deinking, for example, waste OA paper or telephone directories by using a deinking composition containing as an effective component a reaction mixture (III) obtained by conducting the addition reaction of ethylene oxide and propylene oxide with a mixture (I) comprising a fat and oil (a) and a mono- to hexahydric alcohol (b) and/or with a transesterification mixture (II) obtained by conducting the transesterification reaction of a fat and oil (a) with a mono- to hexahydric alcohol (b), in such a manner that the molar ratio of ethylene oxide to propylene oxide which are used as starting materials ranges from 0.8 to 1.2 and that the molar number of ethylene oxide which is used for the addition reaction ranges from 50 to 100 mol per mole of the fat and oil (a).

Deinking method

A deinking composition for use in the reclamation of waste paper consisting essentially of a mixture of higher fatty acids having 8 to 24 carbon atoms, or salts thereof, wherein the average carbon atom number of said fatty acids in said mixture ranges from 12.7 to 21.5, and wherein the content of higher fatty acids having 20 to 24 carbon atoms or salts thereof, ranges from 9.6 to 70.6% by weight, said mixture having an iodine value (IV) of not greater than 45.

Deinking method and deinking composition

A deinking composition which shows a good deinking performance, a good defoaming property and excellent operation characteristics whereby a deinked pulp having a high whiteness and little contamination with the total remaining ink can be obtained in the reclamation of waste papers by flotation, washing or a combination procedure thereof and wherein the deinking composition comprises a reaction mixture (II), as a deinking agent, obtained by the addition reaction of alkylene oxide (D) with a mixture (I) comprising a fat and oil (A) which is constituted with a mixture of higher fatty acids (a) comprising fatty acids having 8 to 24 carbon atoms; having an average carbon atom number of from 12.7 to 22.5; containing from 9.6 to 70.6% by weight of higher fatty acids having 20 to 24 carbon atoms and having an iodine value (IV) of 70 or less and glycerol (b-1), and/or, a transesterification reaction mixture (B) obtained by reacting the fat and oil (A) with glycerol (b-2), and at least one mono- to tetradecahydric alcohol (C).

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Wakayama, Japan

Takanobu Shiroishi