Title of Invention | A PROCESS FOR PREPARING A BOROSILICATE GLASS OF HIGH CHEMICAL RESISTANCE AND LOW VISCOSITY |
---|---|
Abstract | The invention relates to a process for preparing borosilicate glass of high chemical" resistance and low viscosity which contains zirconium oxide and lithium oxide, having class 1 hydrolytic resistance, in accordance with DIN ISO 719, class 1 acid resistance, in accordance with DIN 12116, and class 1 caustic lye resistance, in accordance with DIN ISO 659, and with a low working point VA of between 1180°C to 1230°C and a coefficient of thermal expansion oc20/300 of 4.9 x 10-6 K-1, with the composition (in % by weight, based on oxide) : SiO2 73.0 -75.0; B2O3 7.0 -10.0; Al2O3 5.0 -7.0; zrO2 1.0 -3.0; Li2O 0.5 -1.5; Na20 0 -10.0; K2O 0 -10.0; MgO 0- 3.0; CaO 0 -3.0; BaO 0 -3.0; SrO 0 -3.0; ZnO 0 -3.0; SiO2/B2O3 ratio ~7 .5; L SiO2+AI2O3+ZrO2 80.0 -83.0; L MgO+CaO+BaO+SrO+ZnO ~3.0 and Fluorides 0- 3. The glass is particularly suitable for use as a versatile primary packaging mat~rial for pharmaceuticals, for example as ampoule glass. |
Full Text | The present invention relates to a process for preparing borosilicate glass of high chemical resistance and low viscosity. For use as primary packaging material, for example as ampoule glass, the pharmaceutical industry requires glasses having extremely high chemicals resistance. The commercial pharmaceutical ampoule glasses known hitherto are in hydrolytic resistance class (H) 1 (in accordance with DIN ISO 719), acid resistance class (S) 1 (in accordance with DIN 12116) and caustic lye resistance class (L) 2 (in accordance with DIN ISO 695) . This prior art is represented by the glass Fiolax® clear, Code No. 8412 Si02 74.7; B203 10.0; Al303 5.0; Na20 6.5; CaO 1.5; BaO 2.0; fluorides 0.3% by weight) and JENA instrument glass Ggl 490/5 (Si02 73.2; B203 11.0; A1203 5.3; Na20 7.0; K20 0.2; CaO 0.8; BaO 2.5% by weight) , which have a weight loss of 100 mg/dm2 (in accordance with DIN ISO 695) . A class 1 caustic lye resistance, i.e. a weight loss of However, an important requirement in the pharmaceuticals industry is the provision of primary packaging materials having significantly improved caustic lye resistance to enable packaging of recently developed injections which exert, stronger basic attack on the contents. Practical experience has shown that safeguarding of the caustic lye resistance in the production process requires the development of glasses in the laboratory having weight losses of less than 65 to 70 mg/dm2, i.e. safely within caustic lye class 1. Naturally, the achievement of this requirement must not impair the other important glass and glass; production properties. For example, H = 1 and S = 1 must Thus, at an a value o£ approx. 4.y x _LU w K~~, an excellent chemicals resistance of H = 1, S = 1 and-L = 1 (weight loss Since CaO has a stabilizing action on the acid resistance# small amounts should be possible in the glass if possible. Small amounts of BaO are likewise helpful in order to further reduce the viscosity and to lower the melting point. On the other hand, it may also be necessary for the glass to contain only very little BaO and CaO, or none at all, since it is known that these components can react in an undesired manner with some specific inj ection solutions. If the respective pharmaceutical and industrial areas of application do not make the highest demands regarding chemicals resistance, the glass properties can be further modified by addition of the further bivalent components SrO, MgO and ZnO and by varying the CaO and BaO contents. However, their total content must remain restricted to a maximum of 3.0% by weight, through which the novel composition differs from the composition disclosed in DE 42 3 0 607 CI (E MgO + CaO + BaO + ZnO + SrO + Zr02 = 6 to 10 = E MgO + CaO + BaO + ZnO + SrO = 3 to 9.5 if Zr02 « 0.5 to 3). In addition, small amounts of fluorides can be added to the novel glass compositions in order to accelerate melting or to reduce the viscosity further, or known refining agents, such as chlorides and Sb203, can be added. Accordingly, the present invention provides a process for preparing borosilicate glass of high chemical resistance low viscosity comprising the steps of batch formulation, melting refining, homogenization and conditioning of glass followed by hot forming, wherein the glass formed has a composition of Si02 73.0 - 75.0 B203 7.0 - 10.0 A1203 5.0 - 7.0 Zr02 1.0 - 3.0 Li20 0.5 - 1.5 Na20 0 - 10.0 K20 0 - 10.0 MgO 0 - 3.0 CaO 0 - 3.0 BaO 0 - 3.0 SrO 0 - 3.0 ZnO 0 - 3.0 Fluorides 0 - 3.0 with Si02/B203 >7.5 2 Si02+Al203+Zr02 80.0 - 83.0 S MgO+CaO+BaO+SrO+ZnO in percentage by weight based on oxides. Working Examples: Table 1 shows novel glass compositions and their essential properties relating to the invention. It can be seen that, if the defined coefficient of thermal expansion of oc20/300 = 4.9 x 10"6 K"1 is observed, the caustic lye resistance L, expressed by low weight loss values of from 58 to 65 mg/dm , is very safely within class 1, and the working points are low, with VA —-—-—-—. WE CLAIM: 1. A process for preparing borosilicate glass of high chemical resistance low viscosity comprising the steps of batch formulation, melting refining, homogenization and conditioning of glass followed by hot forming, wherein the glass formed has a composition of Si02 73.0 - 75.0 B203 7.0 - 10.0 A1203 5.0 - 7.0 Zr02 1.0 - 3.0 Li20 0.5 - 1.5 Na20 0 - 10.0 K20 0 - 10.0 MgO 0 - 3.0 CaO 0 - 3.0 BaO 0 - 3.0 SrO 0 - 3.0 ZnO 0 - 3.0 Fluorides 0 - 3.0 with Si02/B203 >7.5 Z Si02+Al203+Zr02 80.0 - 83.0 I MgO+CaO+BaO+SrO+ZnO in percentage by weight based on oxides. The process as claimed in claim 1, wherein said borosilicate glass has a composition (in % by weight, based on oxide), of Si02 73.0 - 75.0 B203 8.0 - 10.0 A1203 5.0 - 6.0 Zr02 1.0 - 2.0 Li20 0.5 - 1.5 Na20 0-10.0 K20 0 - 10.0 MgO 0 - 3.0 CaO 0-3.0 BaO 0 - 3.0 SrO 0 - 3.0 ZnO 0 - 3.0 with Si02/B203 >7.5 I Si02+Al203+Zr02 80.0 - 83.0 I Li20+Na20+K20 7.0 - 10.0 I MgO+CaO+BaO+SrO+ZnO The process as claimed in claim 1 or claim 2 wherein said borosilicate glass has composition (in % by weight on oxide), of Si02 73.5 - 75.0 B203 8.0 - 10.0 A1203 5.0 - 6.0 Zr02 1.0 - 2.5 Li20 0.5 - 1.5 Na20 0.5 - 5.0 K20 0.5 - 5.0 CaO 0.5 - 2.0 with Si02/B203 >7.5 I Si02+Al203+Zr02 81.0 - 83.0 S Li20+Na20+K20 7.0 - 9.5 The process as claimed in claims 1 or 2 wherein said borosilicate glass has a composition (in % by weight, based on oxide), of Si02 73.5 - 75.0 B203 8.0 - 10.0 A1203 5.0 - 6.0 Zr02 1.0 - 2.5 Li20 0.5 - 1.5 Na20 0 - 3.0 K20 4.0 - 7.0 with Si02/B203 >7.5 S Si02+Al203+Zr02 81.0 - 83.0 Z Li20+Na20+K20 7.0 - 10.0 The process as claimed in any of claims 1 to 3, wherein said borosilicate glass has a composition (in % by weight, based on oxide), of Si02 74.0 - 74.5 B203 8.5 - 9.5 A1,(X 5.3 - 6.0 Zr02 1.6 - 2.0 Li20 0.7 - 1.3 Na20 3.0 - 5.0 K20 2.0 - 5.0 CaO 0.5 - 1.6 with 2 Si02+Al203+Zr02 81.3 - 82.0 2 Li20+Na20+K20 7.0 - 9.5 . The process as claimed in claim 5 wherein said borosilicate glass has a composition (in % by weight, based on oxide), of Si02 74.0 - 74.5 B203 9.0 - 9.5 A1203 5.3 - 5.8 Zr02 1.6 - 2.0 Li20 0.9 - 1.1 Na20 3.0 - 5.0 K20 2.0 - 4.0 CaO 0.8 - 1.2 with I Si02+Al203+Zr02 81.3 - 82.0 I Li20+Na20+K20 7.0 - 9.0 7. A process for preparing borosilicate glass of high chemical resistance low viscosity substantially as herein described and exemplified. |
---|
1482-mas-1996-claims duplicate.pdf
1482-mas-1996-claims original.pdf
1482-mas-1996-correspondance others.pdf
1482-mas-1996-correspondance po.pdf
1482-mas-1996-description complete duplicate.pdf
1482-mas-1996-description complete original.pdf
Patent Number | 207256 | ||||||||
---|---|---|---|---|---|---|---|---|---|
Indian Patent Application Number | 1482/MAS/1996 | ||||||||
PG Journal Number | 26/2007 | ||||||||
Publication Date | 29-Jun-2007 | ||||||||
Grant Date | 01-Jun-2007 | ||||||||
Date of Filing | 22-Aug-1996 | ||||||||
Name of Patentee | SCHOTT-ROHRGLAS GMBH | ||||||||
Applicant Address | THEODOR-SCHMIDT-STRABE 25, 95448 BAYREUTH. | ||||||||
Inventors:
|
|||||||||
PCT International Classification Number | C0303/093 | ||||||||
PCT International Application Number | N/A | ||||||||
PCT International Filing date | |||||||||
PCT Conventions:
|