Pipe joint and manufacturing method of pipe joint

Patent metadata

Field	Value
Publication number	US-12467572-B2
Application number	US-202318453690-A
Country	US
Kind code	B2
Filing date	Aug 22, 2023
Priority date	Feb 26, 2021
Publication date	Nov 11, 2025
Grant date	Nov 11, 2025

Abstract

Provided is a pipe joint including a cylindrical hollow, wherein the wall thickness of a part having the largest wall thickness of the pipe joint is 2 to 7 mm, the ratio of the length of the hollow in the axial direction (L) to the diameter of the hollow (D), (L/D), is 5 or less, the pipe joint contains a copolymer containing tetrafluoroethylene unit and a fluoro(alkyl vinyl ether) unit, the content of the fluoro(alkyl vinyl ether) unit of the copolymer is 2.8 to 6.0% by mass with respect to the whole of the monomer units, the melt flow rate at 372° C. of the copolymer is 4.0 g/10 min or higher and lower than 11.0 g/10 min, and the number of functional groups of the copolymer is 50 or less.

First claim

The invention claimed is:

1 . A pipe joint comprising a cylindrical hollow, wherein
a wall thickness of a part having the largest wall thickness of the pipe joint is 2 to 7 mm, a ratio of a length of the hollow in an axial direction (L) to a diameter of the hollow (D), (L/D), is 5 or less, the pipe joint comprises a copolymer comprising tetrafluoroethylene unit and a fluoro(alkyl vinyl ether) unit, a content of the fluoro(alkyl vinyl ether) unit of the copolymer is 2.8 to 6.0% by mass with respect to the whole of the monomer units, a melt flow rate at 372° C. of the copolymer is 4.0 g/10 min or higher and lower than 11.0 g/10 min, and the total number of —CF═CF 2 , —CF 2 H, —COF, —COOH, —COOCH 3 , —CONH 2 and —CH 2 OH of the copolymer is 50 or less.

2 . The pipe joint according to claim 1 , wherein the length of the hollow in the axial direction (L) is 20 mm or larger.

3 . The pipe joint according to claim 1 , wherein the fluoro(alkyl vinyl ether) unit of the copolymer is perfluoro(propyl vinyl ether) unit.

4 . The pipe joint according to claim 1 , wherein the content of the fluoro(alkyl vinyl ether) unit of the copolymer is 3.5 to 5.5% by mass with respect to the whole of the monomer units.

5 . The pipe joint according to claim 1 , wherein the melt flow rate at 372° C. of the copolymer is 5.0 to 9.0 g/10 min.

6 . The pipe joint according to claim 1 , wherein the melting point of the copolymer is 295 to 315° C.

7 . The pipe joint according to claim 1 , wherein the pipe joint is an injection molded article.

Assignees

• Daikin Ind Ltd

Inventors

• Tsuda Hayato
• Isaka Tadaharu
• ZENKE Yumi
• Yamamoto Yukari
• Yamaguchi Yasuyuki
• Hamada Hiroyuki

Classifications

• C08F2800/20

  as weight or mass percentages · CPC title

• C08F214/262

  with fluorinated vinyl ethers · CPC title

• B29L2023/22

  Tubes or pipes, i.e. rigid (bent tubes not for use as pipe couplings B29L2023/004) · CPC title

• B29K2995/0097

  Thickness · CPC title

• B29K2995/0077

  Yield strength; Tensile strength · CPC title