Method for producing a glass article

Patent metadata

Field	Value
Publication number	US-2019308902-A1
Application number	US-201916379025-A
Country	US
Kind code	A1
Filing date	Apr 9, 2019
Priority date	Apr 9, 2018
Publication date	Oct 10, 2019
Grant date	—

Abstract

A method for producing a glass article having high hydrolytic resistance is provided. A glass tube consisting of borosilicate glass and having an Al2O3 content of less than 1 weight-%, a ZrO2 content of 2-12 weight-%, and a glass transition temperature Tg is reshaped into a glass article and is subsequently subjected to a thermal post-treatment. To reduce the alkali release of the glass article, the glass article is subjected to a treatment temperature of TB≥Tg+5° K over a treatment time of tB≥5 min and is subsequently cooled during the thermal post-treatment.

First claim

What is claimed is:

1 . A method for producing a glass article having high hydrolytic resistance, the method comprising:
reshaping a glass tube into the glass article, the glass tube consisting of borosilicate glass and having an Al 2 O 3 content of less than 1 weight-%, a ZrO 2 content of 2-12 weight-%, and a glass transition temperature T g ; and subsequently subjecting the glass article to a thermal post-treatment, the thermal post-treatment comprising subjecting the glass article to a treatment temperature of T B ≥T g +5° K. over a treatment time of t B ≥5 min and subsequently cooling the glass article.

2 . The method of claim 1 , wherein the borosilicate glass consists of the following composition:

SiO 2
60-78
weight -%;

B 2 O 3
7-20
weight -%;

Li 2 O
0-2
weight -%;

Na 2 O
0-6.5
weight -%;

K 2 O
2.5-12
weight -%;

ZnO
0-2
weight -%;

ZrO 2
2-12
weight -%;

refining agent
0-1
weight -%;

Al 2 O 3
<1
weight -%; and

unavoidable contaminants.

3 . The method of claim 2 , wherein the borosilicate glass further consists of at least one of MgO, CaO, BaO, TiO 2 , or SrO with a total of <2 weight-%

4 . The method of claim 1 , wherein the glass transition temperature is 500° C.≤T g ≤620° C.

5 . The method of claim 1 , further comprising annealing the glass article at the end of the thermal post-treatment.

6 . The method of claim 4 , wherein the annealing occurs in one single furnace.

7 . The method of claim 1 , wherein the treatment temperature is T B ≤T g +100° K.

8 . The method of claim 1 , wherein the treatment time is t B ≤360 m.

9 . The method of claim 1 , wherein the glass article is arranged at a start of the thermal post-treatment in a furnace which is set to the operating temperature T B .

10 . A glass article, consisting of:
a treated borosilicate glass having an Al 2 O 3 content of less than 1 weight-% and a ZrO 2 content of 2-12 weight-%, the glass article having an alkali release of A≤0.5 mg/l Na 2 O equivalency according to ISO 4802 or an alkali release A≤3 mg/l Na 2 O equivalency according to USP 660 (glass grains) or ISO 720 (glass grains).

11 . The glass article of claim 9 , wherein the glass article is in the embodiment of a small glass bottle, a glass vial, an ampoule, a glass ampoule, a cylindrical ampoule, a cartridge, a syringe body, a rod, an internal constructed tubular object, an external constructed tubular object, a tube, a semi-finished product to produce one of the aforementioned articles, or glass grains produced according to USP 660.

12 . The glass article of claim 10 , wherein the glass article has an alkali release A that is ≥15% less compared to an untreated reference glass article of the same composition.

13 . The glass article of claim 10 , wherein the borosilicate glass consists of the following composition:

SiO 2
60-78
weight -%;

B 2 O 3
7-20
weight -%;

Li 2 O
0-2
weight -%;

Na 2 O
0-6.5
weight -%;

K 2 O
2.5-12
weight -%;

ZnO
0-2
weight -%;

ZrO 2
2-12
weight -%;

refining agent
0-1
weight -%;

Al 2 O 3
<1
weight -%; and

unavoidable contaminants.

14 . The glass article of claim 13 , wherein the borosilicate glass further consists of at least one of MgO, CaO, BaO, TiO 2 , or SrO with a total of <2 weight-%.

15 . The glass article of claim 10 , wherein the glass article is a storage container for pharmaceutical substances.

Assignees

• Schott Ag

Inventors

• Grimm Malte
• Kass Christof
• Nass Peter

Classifications

• C03C3/11

  containing halogen or nitrogen · CPC title

• C03C3/118

  containing aluminium · CPC title

• C03B32/00

  Thermal after-treatment of glass products not provided for in groups {C03B19/00} , C03B25/00 - C03B31/00 {or C03B37/00}, e.g. crystallisation, eliminating gas inclusions or other impurities; {Hot-pressing vitrified, non-porous, shaped glass products} · CPC title

• C03C3/091

  containing aluminium · CPC title

• C03C3/093 Primary

  containing zinc or zirconium · CPC title