Fine powders of ketone-containing aromatic polymers and process of manufacture

• US 5,357,040 A
• Filed: 02/24/1993
• Issued: 10/18/1994
• Est. Priority Date: 02/24/1993
• Status: Expired due to Fees

• Current Assignee: Virginia Tech Intellectual Properties, Inc.
• Original Assignee: The Center For Innovative Technology, Virginia Polytechnic Institute and State University, Virginia Tech Intellectual Properties, Inc.
• Inventors: Lyon, Keith R., Gungor, Atilla, Texier, Ann, McGrath, James E., Davis, Richey M.
• Primary Examiner(s): Acquah, Samuel A.
• Application Number:
  US08/022,049
• Time in Patent Office: 601 Days
• Field of Search: 528/480, 528/490, 528/491
• US Class Current: 528/490
• CPC Class Codes: C08G 65/4093 characterised by the process or apparatus used
• CPC Class Codes: C08G 65/48 Polymers modified by chemical after-treatment
• CPC Class Codes: C08J 2365/00 Characterised by the use of macromolecular compounds obtained by reactions forming a carbon-to-carbon link in the main chain C08J2307/00 - C08J2357/00, C08J2361/00 take precedence; Derivatives of such polymers
• CPC Class Codes: C08J 3/12 Powdering or granulating
• CPC Class Codes: H05K 1/0373 containing additives, e.g. fillers H05K1/036 takes precedence

Abstract

Fine particles of semi-crystalline ketone-containing aromatic polymers (PEEK, PEKK, etc.) are produced by controlling the rate and conditions of hydrolysis of an amorphous polyarylketimine intermediate. The choice of acid and its concentrations affects the rate of ketimine hydrolysis and subsequent particle formation. In addition, zero or reduced amounts of agitation during hydrolysis has been found to promote the formation of smaller (submicron) sized particles which are spherical in shape, while greater amounts of agitation or shear stress applied during hydrolysis results in nonspherical, larger particles. Carbon fiber reinforced composites were made from aqueous suspensions of these particles that were dispersed or stabilized by a water soluble polymer.

Claims

1. A method of preparing particles of polyarylketones, comprising the steps of:

preparing an amorphous polyarylketimine precursor;

hydrolyzing said polyarylketimine precursor; and

controlling the hydrolyzing conditions during said hydrolyzing step to produce particles of polyarylketones of a particular size and shape.

2. The method of claim 1 wherein said controlling step includes preventing or reducing agitation of said polyarylketimine precursor during said step of hydrolyzing.

3. The method of claim 1 wherein said controlling step includes using 1-3% HCl for said hydrolyzing step.

4. The method of claim 1 further comprising the step of adding a stabilizer to said particles of polyarylketones to deaggregate said particles.

5. The method of claim 1 wherein said step of controlling produces particles of polyarylketones between 0.5 and 5 μ

m in size.