Daicel Corporation

Daikin Industries, Ltd.

Hidekazu Takeuchi

Masaru Tanaka

Kouichi Umemoto

Hideki Matsuura

Takeru Kashiwagi

Daisuke Shiro

Arisa Kawae

Hisayoshi Ito

Naoyoshi Matsuno

Hideo Yagasaki

Shogo Moroe

Provided is a composition for a refrigeration machine capable of reducing a friction coefficient in friction between sliding members in a refrigeration machine, and a composition kit for a refrigeration machine for providing the composition for a refrigeration machine. A composition for a refrigeration machine of the present disclosure includes a refrigeration machine oil, nanodiamond particles dispersed in the refrigeration machine oil, and a dispersant. The refrigeration machine oil preferably contains a polyvinyl ether, a polyol ester, a polyalkylene glycol, an alkylbenzene, or a mineral oil. The composition kit for a refrigeration machine of the present disclosure includes a refrigeration machine oil (A) containing a base oil and nanodiamond particles dispersed in the base oil, and a refrigerant (B).

Composition for refrigeration machine and composition kit for refrigeration machine

Provided is a method for producing a surface-modified nanodiamond having its surface modified with a group containing a polyglycerin chain in an industrially efficient and safe manner, the surface-modified nanodiamond having excellent solubility or dispersibility in water and a polar organic solvent and great dispersion stability. In an aliphatic alcohol solvent having from 2 to 4 carbon atoms, a nanodiamond or a surface-modified nanodiamond having its surface modified with a group represented by Formula (1): —X—H (1), where in Formula (1), Xrepresents —NH—, —O—, —COO—, or the like, is subjected to ring-opening addition polymerization with glycidol, so as to obtain a surface-modified nanodiamond having its surface modified with a group containing a polyglycerin chain represented by Formula (2): —X—R (2), where in Formula (2), X represents a single bond, —NH—, —O—, —COO—, or the like, and R represents a polyglyceryl group.

Method for producing surface-modified nanodiamond

A nanodiamond particle dispersion including nanodiamond particles highly dispersed in an organic solvent is provided. A nanodiamond particle dispersion of the present invention includes nanodiamond particles dispersed in an organic solvent, in which the nanodiamond particles have a silane compound (excluding a silane compound having a (meth)acryloyl group) bonded to a surface of the nanodiamond particles, the organic solvent has an SP value from 8.0 to 14.0 (cal/cm), and the nanodiamond particles are dispersed with a particle diameter (D50) from 2 to 100 nm. The organic solvent is preferably at least one type of organic solvent selected from ketones, ethers, alcohols, and carbonates.

Nanodiamond particle dispersion

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Tokyo, Japan

Hidekazu Takeuchi