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CN-122003457-A - Polytetrafluoroethylene granulated powder

CN122003457ACN 122003457 ACN122003457 ACN 122003457ACN-122003457-A

Abstract

Provided is a polytetrafluoroethylene granulated powder which can give a molded body having little coloration and excellent crack resistance. A polytetrafluoroethylene granulated powder having a moisture content of 0.020% by mass or less and a Z value of 90 or more.

Inventors

  • Deep View Big
  • Ohfune Isao
  • KATO MANABU
  • KAWAHARA KAZUYA

Assignees

  • 大金工业株式会社

Dates

Publication Date
20260508
Application Date
20241025
Priority Date
20231025

Claims (9)

  1. 1. A polytetrafluoroethylene granulated powder having a moisture content of 0.020% by mass or less and a Z value of 90 or more.
  2. 2. The polytetrafluoroethylene granulated powder according to claim 1, wherein the granulating binder used in granulation is a nonionic surfactant aqueous solution.
  3. 3. The polytetrafluoroethylene granulated powder according to claim 2, wherein the nonionic surfactant aqueous solution is at least 1 selected from the group consisting of polyoxyethylene alkyl ethers, segmented polyalkylene glycols, and alkylamine oxides.
  4. 4. The polytetrafluoroethylene granular powder according to any one of claims 1 to 3, having an average particle diameter of 200 μm to 700 μm.
  5. 5. The polytetrafluoroethylene granular powder according to claim 4, having an average particle diameter of 200 μm to 600 μm.
  6. 6. The polytetrafluoroethylene granulated powder according to any one of claims 1 to 5, having an apparent density of 0.60g/ml to 0.90g/ml.
  7. 7. The polytetrafluoroethylene granular powder according to any one of claims 1 to 6, having an average aspect ratio of 1.25 or less.
  8. 8. The polytetrafluoroethylene granular powder according to any one of claims 1 to 7, wherein the high-temperature volatile component is 0.050% by mass or less.
  9. 9. The polytetrafluoroethylene granulated powder according to any one of claims 1 to 8, wherein the moisture content is 0.001 mass% or less.

Description

Polytetrafluoroethylene granulated powder Technical Field The present disclosure relates to polytetrafluoroethylene granulated powder. Background Conventionally, as a method for producing (granulating) a granular powder of polytetrafluoroethylene, a method of stirring in water containing an organic solvent, a method of stirring in warm water, a method of applying mechanical force (rolling) in a state of being wet with a small amount of an organic solvent, and the like have been known. Patent documents 1 and 2 describe a method of wetting polytetrafluoroethylene powder with a predetermined aqueous surfactant solution and applying mechanical force. Prior art literature Patent literature Patent document 1 Japanese patent laid-open No. 10-298300 Patent document 2 Japanese patent laid-open No. 8-208929 Disclosure of Invention Problems to be solved by the invention The purpose of the present disclosure is to provide a polytetrafluoroethylene granulated powder that can give a molded body that has little coloration and excellent crack resistance. Means for solving the problems The present disclosure (1) relates to polytetrafluoroethylene granulated powder having a moisture content of 0.020% by mass or less and a Z value of 90 or more. The present disclosure (2) relates to the polytetrafluoroethylene granulated powder according to the present disclosure (1), wherein the granulation binder used in granulation is a nonionic surfactant aqueous solution. The present disclosure (3) relates to the polytetrafluoroethylene granulated powder according to the present disclosure (2), wherein the nonionic surfactant aqueous solution is at least 1 selected from the group consisting of polyoxyethylene alkyl ethers, segmented polyalkylene glycols, and alkylamine oxides. The present disclosure (4) relates to polytetrafluoroethylene granulated powder in any combination with any one of the present disclosure (1) to (3), having an average particle diameter of 200 to 700 μm. The disclosure (5) relates to polytetrafluoroethylene granulated powder according to the disclosure (4), wherein the average particle diameter is 200-600 μm. The disclosure (6) relates to polytetrafluoroethylene granulated powder in any combination with any one of the disclosure (1) to (5), wherein the apparent density is 0.60-0.90 g/ml. The present disclosure (7) relates to polytetrafluoroethylene granulated powder in any combination with any one of the present disclosure (1) to (6), having an average aspect ratio of 1.25 or less. The present disclosure (8) relates to polytetrafluoroethylene granulated powder in any combination with any one of the present disclosure (1) to (7), wherein the high-temperature volatile component is 0.050 mass% or less. The present disclosure (9) relates to polytetrafluoroethylene granulated powder in any combination with any one of the present disclosure (1) to (8), wherein the moisture content is 0.001 mass% or less. Effects of the invention According to the present disclosure, it is possible to provide a polytetrafluoroethylene granulated powder which can give a molded body having little coloration and excellent crack resistance. Drawings FIG. 1 is a schematic explanatory view of an apparatus used for measuring fluidity of granulated powder. Detailed Description The present disclosure is specifically described below. The present disclosure relates to Polytetrafluoroethylene (PTFE) granulated powder having a moisture content of 0.020% by mass or less and a Z value of 90 or more. The PTFE granulated powder of the present disclosure has a moisture content and a Z value within specific ranges, and thus can give a molded article having little coloration and excellent crack resistance. The water content of the PTFE granulated powder of the present disclosure is 0.020% by mass or less, preferably 0.015% by mass or less, more preferably 0.010% by mass or less, still more preferably 0.005% by mass or less, still more preferably 0.003% by mass or less, still more preferably 0.002% by mass or less, and particularly preferably 0.001% by mass or less, from the viewpoint that a molded article having more excellent crack resistance can be obtained. The lower limit is not limited and may be 0 mass%. The above moisture content was measured by the following method. The mass of the PTFE pellet powder was measured before and after heating at 150℃for 2 hours, and the mass was calculated according to the following formula. The average value was obtained by taking 3 samples and calculating the samples. The Z value of the PTFE granulated powder of the present disclosure is preferably 91 or more, more preferably 95 or more, still more preferably 100 or more, and may be 110 or less, from the viewpoint that a molded article with less coloration can be obtained. The above-mentioned Z value was measured by the following method. 200G of PTFE pellet powder was charged into a mold having a diameter of 50mm, and the resultant preform (having a diameter of about 50m