Feedstock Gel and Method of Making Glass-Ceramic Articles from the Feedstock Gel

Patent metadata

Field	Value
Publication number	US-2019016622-A1
Application number	US-201715650490-A
Country	US
Kind code	A1
Filing date	Jul 14, 2017
Priority date	Jul 14, 2017
Publication date	Jan 17, 2019
Grant date	—

Abstract

A method of making a glass-ceramic article includes synthesizing a feedstock gel that includes a base oxide network comprising Na 2 O, CaO, and SiO 2 , in which a molar ratio of Na 2 O:CaO:SiO 2 in the gel is 1:2:3, and then converting the feedstock gel into a glass-ceramic article such as a container or a partially-formed container. The conversion of the feedstock gel into a glass-ceramic container may be performed at a temperature that does not exceed 900° C. and may include the steps of pressing the feedstock gel into a compressed solid green-body, sintering the green-body into a solid monolithic body of a glass-ceramic material, deforming the solid monolithic glass-ceramic body into a glass-ceramic preform, and cooling the preform. A glass-ceramic article having a glass-ceramic material that has a molar ratio of Na 2 O:CaO:SiO 2 that is 1:2:3 is also disclosed.

First claim

1 . A method of making a glass-ceramic article, the method comprising:
synthesizing a feedstock gel that includes a base oxide network comprising Na 2 O, CaO, and SiO 2 in which a molar ratio of Na 2 O:CaO:SiO 2 is 1:2:3; pressing the feedstock gel into a compressed solid green-body; sintering the compressed solid green-body of the feedstock gel at a temperature below 900° C. to produce a solid monolithic body of a glass-ceramic material having an amorphous residual glass phase and a crystalline phase distributed within the amorphous residual glass phase, the solid monolithic body of a glass-ceramic material having a density that is greater than a density of the feedstock gel; deforming the solid monolithic body of a glass-ceramic material into a glass-ceramic preform having a container shape at a temperature of 600° C. or above; and cooling the glass-ceramic preform into a glass-ceramic article in the form of a container or a partially-formed container.

2 . The method set forth in claim 1 , wherein the step of synthesizing the feedstock gel comprises:
providing an aqueous solution that includes sodium silicate having a Na 2 O:SiO 2 molar ratio; adding a soluble calcium salt to the aqueous solution to form a precipitate having a Na 2 O:CaO:SiO 2 molar ratio that corresponds to the molar ratio of Na 2 O:CaO:SiO 2 in the base oxide network of the feedstock gel; and extracting liquid solvent from the precipitate to produce the feedstock gel.

3 . The method set forth in claim 2 , wherein the calcium salt comprises at least one of calcium nitrate or calcium chloride.

4 . The method set forth in claim 1 , wherein the step of synthesizing the feedstock gel comprises:
providing an aqueous solution that includes an acid catalyst; adding a tetraalkoxysilane to the aqueous solution to form a polysiloxane through hydrolytic polycondensation of the tetraalkoxysilane; adding a soluble sodium salt and a soluble calcium salt to the aqueous solution to introduce sodium and calcium, respectively, into the polysiloxane; forming a precipitate that has a Na 2 O:CaO:SiO 2 molar ratio that corresponds to the molar ratio of Na 2 O:CaO:SiO 2 in the base oxide network of the feedstock gel; and extracting liquid solvent from the precipitate to produce the feedstock gel.

5 . The method set forth in claim 4 , wherein the tetraalkoxysilane is tetraethyl orthosilicate, tetramethyl orthosilicate, or a mixture thereof.

6 . The method set forth in claim 4 , wherein the acid catalyst is nitric acid, acetic acid, or hydrochloric acid.

7 . The method set forth in claim 4 , wherein the sodium salt comprises at least one of sodium hydroxide, sodium nitrate, or sodium chloride, and wherein the calcium salt comprises at least one of calcium nitrate or calcium chloride.

8 . The method set forth in claim 1 , wherein the step of sintering the feedstock gel into the solid monolithic body of a glass-ceramic material is performed at a temperature of 600° C. to 900° C.

9 . The method set forth in claim 1 , wherein the step of deforming the solid monolithic body of a glass-ceramic material into the glass-ceramic preform is performed at a temperature between 600° C. and 750° C.

10 . The method set forth in claim 9 , wherein the step of deforming the solid monolithic body of a glass-ceramic material into the glass-ceramic preform comprises hot-pressing the monolithic body of a glass-ceramic material in a mold cavity.

11 . The method set forth in claim 1 , wherein the glass-ceramic article is a container that comprises a hollow main body that defines an opening and an internal containment space accessible through the opening.

12 . The method set forth in claim 1 , wherein the glass-ceramic article is a partially-formed container.

13 . A method of making a glass-ceramic article, the method comprising:
providing a liquid precursor medium that includes a reactive silicon-containing precursor compound; adding at least one soluble salt to the liquid precursor medium and forming a precipitate from the liquid precursor medium that comprises Na 2 O, CaO, and SiO 2 with a molar ratio of Na 2 O:CaO:SiO 2 being 1:2:3; the at least one soluble salt being a soluble sodium salt, a soluble calcium salt, or both a soluble sodium salt and a soluble calcium salt; extracting liquid solvent from the precipitate to produce a feedstock gel having a molar ratio of Na 2 O:CaO:SiO 2 that is the same as the molar ratio of Na 2 O:CaO:SiO 2 in the precipitate; and converting the feedstock gel into a glass-ceramic article at a temperature that does not exceed 900° C.

14 . The method set forth in claim 13 , wherein the step of providing the liquid precursor medium comprises providing an aqueous solution that includes sodium silicate having a Na 2 O:SiO 2 molar ratio, and wherein the step of adding at least one soluble salt to the liquid precursor medium comprises adding a soluble calcium salt to the aqueous solution to reduce the Na 2 O:SiO 2 molar ratio and to form the precipitate.

15 . The method set forth in claim 13 , wherein the step of providing the liquid precursor medium comprises adding a tetraalkoxysilane to an aqueous solution that includes an acid catalyst to form a polysiloxane through hydrolytic polycondensation of the tetraalkoxysilane, and wherein the step of adding at least one soluble salt to the liquid precursor medium comprises adding a soluble sodium salt and a soluble calcium salt to the aqueous solution to introduce sodium and calcium, respectively, into the polysiloxane to thereby form the precipitate.

16 . The method set forth in claim 13 , wherein the step of converting the feedstock gel into the glass-ceramic article comprises:
sintering a compressed solid green-body of the feedstock gel at a temperature below 900° C. to produce a solid monolithic body of a glass-ceramic material having an amorphous residual glass phase and a crystalline phase distributed within the amorphous residual glass phase, the solid monolithic body of a glass-ceramic material having a density that is greater than a density of the feedstock gel; hot-pressing the solid monolithic body of a glass-ceramic material into a glass-ceramic preform at a temperature at or above 600° C.; and cooling the glass-ceramic preform into the glass-ceramic article.

17 . The method set forth in claim 16 , wherein the step of sintering the feedstock gel is performed at a temperature 600° C. to 900° C.

18 . The method set forth in claim 16 , wherein the step of hot-pressing the monolithic body of a glass-ceramic material in a mold cavity comprises advancing a retractable plunger against the body of a glass-ceramic material so as to force the glass-ceramic material to flow and deform upwards around the plunger into the glass-ceramic preform at a temperature at or above 600° C. while applying a pressure of 5 MPa to 25 MPa.

19 . A glass-ceramic container comprising:
a hollow main body that comprises a bottom wall, an upstanding side wall extending from a periphery of the bottom wall, and a neck portion extending from the side wall opposite the bottom wall and defining an opening to an internal containment space defined by the main body, the hollow main body being comprised of a glass-ceramic material having an amorphous residual glass phase and a crystalline phase distributed within the amorphous residual glass phase, the glass-ceramic material having an overall composition in which a molar ratio of Na 2 O:CaO:SiO 2 is 1:2:3.

20 . The glass-ceramic container set forth

Assignees

• Owens Brockway Glass Container

Inventors

• Cooper Scott P

Classifications

• C03C10/0009 Primary

  containing silica as main constituent · CPC title

• C03B19/063

  by hot-pressing powders · CPC title

• C03C3/087

  containing calcium oxide, e.g. common sheet or container glass · CPC title

• C04B2235/656

  characterised by specific heating conditions during heat treatment · CPC title

• C03B32/02 Primary

  Thermal crystallisation, e.g. for crystallising glass bodies into glass-ceramic articles {(C03B27/012 takes precedence)} · CPC title