# US 2019/0375893 A1 · Polyamide particles and method for producing polyamide particles

> Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt

- Number: US 2019/0375893 A1
- Document ID: US20190375893A1
- Status: Published application
- Kind: A1
- Application number: 16/476,934
- Filed: 2018-01-25
- Published: 2019-12-12
- Earliest claimed: 2017-02-14
- Assignees: Kureha Corporation
- Applicants: Kureha Corporation
- Inventors: Daisuke MURANO; Kazuyuki YAMANE; Yingge XIAO; Yoshinori SUZUKI
- Web page: https://patentgrep.com/patent/US20190375893A1

## CPC

- C08G 69/24: Pyrrolidones or piperidones
- C08G 69/16: Preparatory processes
- C08J 3/14: by precipitation from solutions {(C08J3/122 takes precedence)}
- C08G: MACROMOLECULAR COMPOUNDS OBTAINED OTHERWISE THAN BY REACTIONS ONLY INVOLVING UNSATURATED CARBON-TO-CARBON BONDS
- C08J: WORKING-UP; GENERAL PROCESSES OF COMPOUNDING; AFTER-TREATMENT NOT COVERED BY SUBCLASSES C08B, C08C, C08F, C08G or C08H (working, e.g. shaping, of plastics B29)

## Abstract

Provided are non-spherical polyamide particles having small variations in particle shape. The polyamide particles include a polyamide including repeating structural units having at least one alkylene group and at least one amide bond, wherein each of the at least one alkylene group has 1 to 3 carbon atoms. The main shape of the particles is a non-spherical shape with a circularity of less than 0.98, and a coefficient of variation (CV) of the circularity distribution is 30% or less. [Chemical Formula 1] Formula (1) [Chemical Formula 2] Formula (2) (Equation 1) Sphericity=[(Σ(short diameter/long diameter))/n]×100 (4)

## Claims

### Claim 1

Polyamide particles comprising a polyamide that comprises repeating structural units having at least one alkylene group and at least one amide bond, each of the at least one alkylene group having 1 to 3 carbon atoms; wherein
a main shape of the particles is a non-spherical shape with a circularity of less than 0.98; and
a coefficient of variation (CV) of a circularity distribution is 30% or less.

### Claim 2 (depends on 1)

The polyamide particles according to claim 1, wherein a D90/D50 value of a particle size distribution is 10 or less.

### Claim 3 (depends on 1)

The polyamide particles according to claim 1, wherein the D90/D50 value of the particle size distribution is 5 or less.

### Claim 4 (depends on 1)

The polyamide particles according to claim 1, wherein the structural unit is represented by the following formula (1):
where, x is 2, 3, or 4.

### Claim 5 (depends on 1)

The polyamide particles according to claim 1, wherein the structural unit is represented by the following formula (2):
where, y is 2 or 3, and z is 2, 3, or 4.

### Claim 6

A method for producing polyamide particles, the method comprising:
a polymerization step of preparing, through polymerization, a polyamide that comprises repeating structural units having at least one alkylene group and at least one amide bond, each of the at least one alkylene group having 1 to 3 carbon atoms;
a dissolution step of dissolving the polyamide obtained in the polymerization step in hot water; and
a precipitation step of precipitating particles of the polyamide by cooling a solution obtained in the dissolution step under stirring.

### Claim 7 (depends on 6)

The method for producing polyamide particles according to claim 6, wherein, in the precipitation step, the solution is cooled at a faster cooling rate than that of natural cooling.