Patent ID: 9646641
Date: 2017-05-09
CPC Classifications: G11B

Claim:
1. A magnetic coating composition, which is a magnetic coating composition for a magnetic recording medium and comprises the following components (A) to (D): (A) a compound denoted by formula (1) below having an acid number ranging from 10.4 to 224 mgKOH/g and a weight average molecular weight ranging from 1,000 to 15,000: wherein, in formula (1), R (B) binder; (C) ferromagnetic powder; and (D) solvent, wherein the compound (A) is selected from the group consisting of the following compounds A-1, A-2, A-3, A-4, A-5, A-6, A-8, A-9, A-10, A-11, A-12, A-13, A-14, A-15, A-16, A-18, A-20, A-23, A-24, A-27, A-28 and A-32: A-1 has the following structure with a weight average molecular weight of 2300 and an acid number of 28.5 mgKOH/g: A-2 has the following structure with a weight average molecular weight of 2100 and an acid number of 56.0 mgKOH/g: A-3 has the following structure with a weight average molecular weight of 2300 and an acid number of 25.0 mgKOH/g: A-4 has the following structure with a weight average molecular weight of 1900 and an acid number of 62.3 mgKOH/g: A-5 has the following structure with a weight average molecular weight of 4800 and an acid number of 28.1 mgKOH/g: A-6 has the following structure with a weight average molecular weight of 1200 and an acid number of 99.9 mgKOH/g: A-8 has the following structure with a weight average molecular weight of 2500 and an acid number of 46.7 mgKOH/g: A-9 has the following structure with a weight average molecular weight of 4600 and an acid number of 28.1 mgKOH/g: A-10 has the following structure with a weight average molecular weight of 2300 and an acid number of 46.5 mgKOH/g: A-11 has the following structure with a weight average molecular weight of 3000 and an acid number of 33.3 mgKOH/g: A-12 has the following structure with a weight average molecular weight of 4800 and an acid number of 72.9 mgKOH/g: A-13 has the following structure with a weight average molecular weight of 9500 and an acid number of 58.8 mgKOH/g: A-14 has the following structure with a weight average molecular weight of 3300 and an acid number of 36.3 mgKOH/g: A-15 has the following structure with a weight average molecular weight of 2200 and an acid number of 51.3 mgKOH/g: A-16 has the following structure with a weight average molecular weight of 1100 and an acid number of 105.3 mgKOH/g: A-18 has the same structure as A-13 with a weight average molecular weight of 12600 and an acid number of 48.5 mgKOH/g; A-20 has the same structure as A-2 with a weight average molecular weight of 9600 and an acid number of 10.4 mgKOH/g; A-23 has the same structure as A-13 with a weight average molecular weight of 3500 and an acid number of 159.4 mgKOH/g; A-24 has the same structure as A-13 with a weight average molecular weight of 3000 and an acid number of 187.1 mgKOH/g; A-27 has the following structure with a weight average molecular weight of 3000 and an acid number of 37.3 mgKOH/g: A-28 has the following structure with a weight average molecular weight of 2600 and an acid number of 43.1 mgKOH/g: A-32 has the following structure with a weight average molecular weight of 5100 and an acid number of 22.0 mgKOH/g: