Polyamide fine particles and method of producing the same
AssigneeToray Industries, Inc.
InventorsKen Komiya, Akiyoshi Tamai, Kenichi Utazaki
Life of this patent
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Abstract
Polyamide fine particles include a polymer or a copolymer including a repeating structure unit represented by Formula (1) as a main component, wherein a ratio (r/ABET) of a porosity r occupying a particle surface and a BET specific surface area ABET that is a specific surface area of the particle surface measured by a BET method is 6.0 or more and 100.0 or less: wherein x is an integer of 2 or more and 3 or less.
Claims18
Polyamide fine particles comprising a polymer or a copolymer including a repeating structure unit represented by Formula (1) as a main component, wherein
- a ratio (r/ABET) of a porosity r occupying a particle surface and a BET specific surface area ABET that is a specific surface area of the particle surface measured by a BET method is 6.0 or more and 100.0 or less:
- wherein x is an integer of 2 or more and 3 or less, and
- wherein the polyamide fine particles have a sphericity of 90 or more.
Polyamide fine particles comprising a polymer or a copolymer including a repeating structure unit represented by Formula (1) as a main component, wherein
- a sphericity is 96 or more,
- an amount of impurities contained is 0.50% by weight or less,
- a standard deviation of sphericity is 2.00 or less, and
- a stability index over time that is an index representing stability toward deterioration in feel to the polyamide fine particles that are continuously rubbed is calculated in accordance with the following formula and is 0.60 or more:
- wherein x is an integer of 2 or more and 3 or less, and
- temporal stability index=1/(Standard deviation of sphericity×(1+Amount of impurities contained)) wherein the standard deviation of sphericity is a standard deviation of sphericity of the polyamide fine particles, and the amount of impurities contained is an amount of impurities contained in the polyamide fine particles.
A method of producing polyamide fine particles using a resin (A) and a resin (B) as raw materials, the resin (A) being a polymer or a copolymer including a repeating structure unit represented by Formula (1) as a main component, the resin (B) being an emulsion formation resin capable of forming an emulsion with the resin (A) in a molten state, the method comprising:
- an emulsion formation step of melt mixing the resin (A) and the resin (B) at a melting temperature equal to or higher than a melting point of the resin (A) and a melting point of the resin (B) to form an emulsion in which the resin (A) in a particulate form is dispersed in the resin (B);
- an immobilization step of cooling a molten mixture in which the emulsion of the resin (A) and the resin (B) is formed to a temperature equal to or lower than a crystallization temperature of the resin (A) to immobilize the emulsion;
- and
- a collecting step of removing the resin (B) by washing with a washing solution that is a non-solvent of the resin (A) to collect polyamide fine particles formed of the resin (A), wherein
- a melt viscosity ratio of the resin (A) and the resin (B) at 270° C. is 4.3 or more and 125.0 or less:
- wherein x is an integer of 2 or more and 3 or less.
Dependencies are inferred from the claim text.