Brass alloy for writing instrument tips

Patent metadata

Field	Value
Publication number	US-12522014-B2
Application number	US-202118245740-A
Country	US
Kind code	B2
Filing date	Sep 16, 2021
Priority date	Sep 17, 2020
Publication date	Jan 13, 2026
Grant date	Jan 13, 2026

Abstract

A tip for a handheld writing instrument-includes a brass alloy comprising the following composition: Cu in an amount of from about 52 wt.-% to about 62 wt.-%, Sn in an amount of from about 0.1 wt.-% to about 1.0 wt.-%, Fe in an amount of from about 0.1 wt.-% to about 1.0 wt.-%, Si in an amount of from about 0.05 wt.-% to about 0.5 wt.-%, Ni in an amount of from about 0.05 wt.-% to about 0.5 wt.-%, Pb if present, in an amount of less than about 0.05 wt.-%, optionally other elements in a total amount of less than about 3 wt.-% (impurities), and Zn as balance.

First claim

The invention claimed is:

1 . A tip for a handheld writing instrument, the tip comprising a brass alloy consisting essentially of:
Cu: in an amount of from about 52 wt.-% to about 62 wt.-%, Sn: in an amount of from about 0.10 wt.-% to about 1.0 wt.-%, Fe: in an amount of from about 0.10 wt.-% to about 1.0 wt.-% Si: in an amount of from about 0.05 wt.-% to about 0.50 wt.-%, Ni: in an amount of from about 0.05 wt.-% to about 0.50 wt.-%, Bi: in an amount of from about 0.05 wt.-% to about 0.70 wt.-%, Te: in an amount of from about 0.05 wt.-% to about 0.20 wt.-%, Se: in an amount of from about 0.05 wt.-% to about 0.20 wt.-%, Pb: if present, in an amount of less than about 0.05 wt.-%, and Zn: as balance.

2 . The tip according to claim 1 , wherein the brass alloy contains less than about 0.03 wt.-% Pb.

3 . The tip according to claim 1 , wherein the brass alloy is substantially free of or free of Pb.

4 . The tip according to claim 1 , wherein the brass alloy contains at least about 35 wt.-% Zn.

5 . The tip according to claim 1 , wherein the brass alloy contains between about 40 wt.-% and about 44 wt.-% Zn.

6 . The tip according to claim 1 , wherein, in a cross-sectional cut of the tip, the brass alloy is characterized by a microstructure comprising acicular α-phases and acicular β-phases.

7 . The tip according to claim 6 , wherein the microstructure comprises domains in which a plurality of α-phases and a plurality of β-phases are alternatingly arranged.

8 . The tip according to claim 6 , wherein the microstructure comprises domains in which the α-phases and/or the β-phases have an aspect ratio of at least about 5.

9 . The tip according to claim 6 , wherein the microstructure comprises domains in which the α-phases and/or the β-phases have an aspect ratio of at least about 10.

10 . The tip according to claim 6 , wherein the microstructure comprises domains in which the α-phases and/or the β-phases have a length of at least about 50 μm.

11 . The tip according to claim 6 , wherein the β-phases of the microstructure occupy about 20 to about 55% by area.

12 . The tip according to claim 6 , wherein the β-phases are uniformly dispersed in the microstructure.

13 . A handheld writing instrument for dispensing a solvent writing ink comprising:
a tubular body, and a tip according to claim 1 , wherein the tip is adapted to be coupled to the tubular body.

14 . A process of preparing the tip according to claim 1 , comprising:
a) melt mixing a composition consisting essentially of:
Cu: in the amount of from about 52 wt.-% to about 62 wt.-%,
Sn: in the amount of from about 0.10 wt.-% to about 1.0 wt.-%,
Fe: in the amount of from about 0.10 wt.-% to about 1.0 wt.-%,
Si: in the amount of from about 0.05 wt.-% to about 0.50 wt.-%,
Ni: in the amount of from about 0.05 wt.-% to about 0.50 wt.-%,
Bi: in the amount of from about 0.05 wt.-% to about 0.70 wt.-%,
Te: in the amount of from about 0.05 wt.-% to about 0.20 wt.-%,
Se: in the amount of from about 0.05 wt.-% to about 0.20 wt.-%,
Pb: if present, in the amount of less than about 0.05 wt.-%; and
Zn: as balance,
b) extruding the melt to a solid body, and c) processing the solid body to a tip.

15 . The tip according to claim 1 , wherein the brass alloy consists essentially of:
Cu: in an amount of from about 54 wt.-% to about 60 wt.-%, Sn: in an amount of from about 0.25 wt.-% to about 0.35 wt.-%, Fe: in an amount of from about 0.20 wt.-% to about 0.30 wt.-%, Si: in an amount of from about 0.08 wt.-% to about 0.12 wt.-%, and Ni: in an amount of from about 0.15 wt.-% to about 0.25 wt.-%.

Assignees

• SOCIéTé BIC

Inventors

• Bouchet Julien

Classifications

• C22F1/08

  of copper or alloys based thereon · CPC title

• C22C9/04 Primary

  with zinc as the next major constituent · CPC title

• C22C1/02

  by melting {(C22C1/1036 takes precedence)} · CPC title

• B43K1/10

  Wire nibs · CPC title

• B43K1/082

  Balls · CPC title