US4053679A — Chemically strengthened opal glass

Claim 1

Independent Claim 147 words

A spontaneously opalized glass capable of being strengthened by ion-exchange with potassium ions, comprising by weight on the oxide basis: 34 to 60 percent SiO 2 6 to 23 percent Na 2 O 0 to 15 percent K 2 O 18to 26 percent (Na 2 O + K 2 O) 0 to 18 percent Al 2 O 3 0 to 20 percent ZrO 2 4 to 21 percent (Al 2 O 3 + ZrO 2 ) 7 to 20 percent P 2 O 5 0 to 9 percent CaO 0 to 9 percent SrO 2 to 9 percent (CaO + SrO) less than 0.1 percent Li 2 O said constituents comprising at least 90 percent by weight of the glass and proportioned relative to one another so as to provide the glass with a viscosity of 100 poises at a temperature less than 2800° F. (1538° C.).

Claim 2

Dependent Claim 147 words

A spontaneously opalized glass capable of being strengthened by ion-exchange with potassium ions, comprising by weight on the oxide basis: 34 to 60 percent SiO 2 6 to 23 percent Na 2 O 0 to 15 percent K 2 O 18to 26 percent (Na 2 O + K 2 O) 0 to 18 percent Al 2 O 3 0 to 20 percent ZrO 2 4 to 21 percent (Al 2 O 3 + ZrO 2 ) 7 to 20 percent P 2 O 5 0 to 9 percent CaO 0 to 9 percent SrO 2 to 9 percent (CaO + SrO) less than 0.1 percent Li 2 O said constituents comprising at least 90 percent by weight of the glass and proportioned relative to one another so as to provide the glass with a viscosity of 100 poises at a temperature less than 2800° F. (1538° C.).

Claim 3

Dependent Claim 94 words

The glass of claim 1 comprising by weight on the oxide basis: 38 to 60 percent SiO 2 10 to 18 percent Na 2 O 0 to 11 percent K 2 O 18 to 23 percent (Na 2 O + K 2 O) 4 to 18 percent Al 2 O 3 0 to 10 percent ZrO 2 4 to 20 percent (Al 2 O 3 + ZrO 2 ) 10 to 20 percent P 2 O 5 0 to 9 percent CaO 0 to 9 percent SrO 4 to 9 percent (CaO + SrO).

Claim 4

Dependent Claim 87 words

The glass of claim 1 wherein the glass consists essentially of by weight on the oxide basis: 39 to 51 percent SiO 2 15 to 18 percent Na 2 O 1 to 4 percent K 2 O 19 to 22 percent (Na 2 O + K 2 O) 4 to 13 percent Al 2 O 3 1 to 5 percent ZrO 2 10 to 18 percent P 2 O 5 0 to 7 percent CaO 0 to 7 percent SrO 5 to 7 percent (CaO + SrO).

Claim 5

Dependent Claim 195 words

A chemically strengthened, spontaneously opalized glass article exhibiting a surface compressive stress after being subjected to surface abrasion composed of an interior portion which is in tension and surface compressive layer, said interior portion comprised of by weight on the oxide basis: 34 to 60 percent SiO 2 6 to 23 percent Na 2 O 0 to 15 percent K 2 O 18 to 26 percent (Na 2 O + K 2 O) 0 to 18 percent Al 2 O 3 0 to 20 percent ZrO 2 4 to 21 percent (Al 2 O 3 + ZrO 3 ) 7 to 20 percent P 2 O 5 0 to 9 percent CaO 0 to 9 percent SrO 2 to 9 percent (CaO + SrO) less than 0.1 percent Li 2 O said constituents comprising at least 90 percent by weight of said interior portion and proportioned relative to one another so as to provide the glass with a viscosity of 100 poises at a temperature less than 2800° F. (1538° C.), and said surface layer having a higher content of K 2 O and a lower content of Na 2 O than the interior portion.

Claim 6

Dependent Claim 195 words

A chemically strengthened, spontaneously opalized glass article exhibiting a surface compressive stress after being subjected to surface abrasion composed of an interior portion which is in tension and surface compressive layer, said interior portion comprised of by weight on the oxide basis: 34 to 60 percent SiO 2 6 to 23 percent Na 2 O 0 to 15 percent K 2 O 18 to 26 percent (Na 2 O + K 2 O) 0 to 18 percent Al 2 O 3 0 to 20 percent ZrO 2 4 to 21 percent (Al 2 O 3 + ZrO 3 ) 7 to 20 percent P 2 O 5 0 to 9 percent CaO 0 to 9 percent SrO 2 to 9 percent (CaO + SrO) less than 0.1 percent Li 2 O said constituents comprising at least 90 percent by weight of said interior portion and proportioned relative to one another so as to provide the glass with a viscosity of 100 poises at a temperature less than 2800° F. (1538° C.), and said surface layer having a higher content of K 2 O and a lower content of Na 2 O than the interior portion.

Claim 7

Dependent Claim 101 words

The glass article of claim 4 wherein said interior portion is comprised of by weight on the oxide basis: 38 to 60 percent SiO 2 10 to 18 percent Na 2 O 0 to 11 percent K 2 O 18 to 23 percent (Na 2 O + K 2 0) 4 to 18 percent Al 2 O 3 0 to 10 percent ZrO 2 4 to 20 percent (Al 2 O 3 + ZrO 2 ) 10 to 20 percent P 2 O 5 0 to 9 percent CaO 0 to 9 percent SrO 4 to 9 percent (CaO + SrO).

Claim 8

Dependent Claim 89 words

The glass article of claim 4 wherein said interior portion consists essentially of by weight on the oxide basis: 39 to 51 percent SiO 2 15 to 18 percent Na 2 O 1 to 4 percent K 2 O 19 to 22 percent (Na 2 O + K 2 O) 4 to 13 percent Al 2 O 3 1 to 5 percent ZrO 2 10 to 18 percent P 2 O 5 0 to 7 percent CaO 0 to 7 percent SrO 5 to 7 percent (CaO + SrO).

Claim 9

Dependent Claim 17 words

The glass article of claim 4 wherein said surface compressive layer is at least 50 microns thick.

Claim 10

Dependent Claim 17 words

The glass article of claim 4 wherein the surface compressive layer is at least 100 microns thick.

Claim 11

Dependent Claim 25 words

The glass article of claim 4 wherein its strength, as measured by abraded rod modulus of rupture is at least 1700 kilograms per square centimeter.

Claim 12

Independent Claim 234 words

A method of strengthening an opal glass article comprising the steps of: a. contacting a source of potassium ions with the surface of a spontaneously opalized glass article comprising by weight on the oxide basis: 34to 60 percent SiO 2 6 to 23 percent Na 2 O 0 to 15 percent K 2 O 18 to 26 percent (Na 2 O + K 2 O) 0 to 18 percent Al 2 O 3 0 to 20 percent ZrO 2 4 to 21 percent (Al 2 O 3 + ZrO 2 ) 7 to 20 percent P 2 O 5 0 to 9 percent CaO 0 to 9 percent SrO 2 to 9 percent (CaO + SrO) less than 0.1 percent Li 2 O said constituents comprising at least 90 percent by weight of the glass article and proportioned relative to one another so as to provide the glass with a viscosity of 100 poises at a temperature less than 2800° F. (1538° C.); b. heating said source of potassium ions while in contact with the glass to a temperature at which potassium ions from said source replace sodium ions in the glass, but essentially below the strain point of the glass, thereby creating a zone of compression at the surface of the glass which extends at least 5 microns into the glass; and c. removing the glass from contact with the potassium ion source.

Claim 13

Independent Claim 234 words

A method of strengthening an opal glass article comprising the steps of: a. contacting a source of potassium ions with the surface of a spontaneously opalized glass article comprising by weight on the oxide basis: 34to 60 percent SiO 2 6 to 23 percent Na 2 O 0 to 15 percent K 2 O 18 to 26 percent (Na 2 O + K 2 O) 0 to 18 percent Al 2 O 3 0 to 20 percent ZrO 2 4 to 21 percent (Al 2 O 3 + ZrO 2 ) 7 to 20 percent P 2 O 5 0 to 9 percent CaO 0 to 9 percent SrO 2 to 9 percent (CaO + SrO) less than 0.1 percent Li 2 O said constituents comprising at least 90 percent by weight of the glass article and proportioned relative to one another so as to provide the glass with a viscosity of 100 poises at a temperature less than 2800° F. (1538° C.); b. heating said source of potassium ions while in contact with the glass to a temperature at which potassium ions from said source replace sodium ions in the glass, but essentially below the strain point of the glass, thereby creating a zone of compression at the surface of the glass which extends at least 5 microns into the glass; and c. removing the glass from contact with the potassium ion source.

Claim 14

Dependent Claim 121 words

The method of claim 10 wherein the opal glass article being stengthened initially comprises by weight on the oxide basis: 38 to 60 percent SiO 2 10 to 18 percent Na 2 O 0to 11 percent K 2 O 18 to 23 percent (Na 2 O + K 2 O) 4 to 18 percent Al 2 O 3 0 to 10 percent ZrO 2 4 to 20 percent (Al 2 O 3 + ZrO 2 ) 10 to 20 percent P 2 O 5 0 to 9 percent CaO 0 to 9 percent SrO 4 to 9 percent (CaO + SrO) less than 0.1 percent Li 2 O said constituents comprising at least 90 percent by weight of the glass article.

Claim 15

Dependent Claim 111 words

The method of claim 10 wherein the opal glass article being strengthened initially comprises by weight on the oxide basis: 39 to 51 percent SiO 2 15 to 18 percent Na 2 O 1 to 4 percent K 2 O 19 to 22 percent (Na 2 O + K 2 O) 4 to 13 percent Al 2 O 3 1 to 5 percent ZrO 2 10 to 18 percent P 2 O 5 durability 0 to 7 percent CaO 0 to 7 percent SrO 5 to 7 percent (CaO + SrO) less than 0.1 percent Li 2 O said constituents comprising at least 90 percent by weight of the glass article.

Claim 16

Dependent Claim 36 words

The method of claim 10 wherein said contacting and heating steps are continued for no more than one hour and thereby produce a compression layer at least 50 microns deep at the surface of the glass.

Claim 17

Dependent Claim 16 words

The method of claim 13 wherein the compression layer produced is at least 100 microns deep.

Claim 18

Dependent Claim 24 words

The method of claim 13 wherein the abraded rod modulus of rupture for the glass is at least doubled by the ion exchange treatment.

Claim 19

Dependent Claim 19 words

The method of claim 10 wherein the source of potassium ions is a molten bath of KNO 3 .

Annuity Stage	Window Opens	Payment Deadline	Surcharge Period Until	Estimated Fee	Status
3.5 Years (Year 4)	1980-10-10	1981-04-11	1981-10-11	$2000.00	Window Closed / Lapsed
7.5 Years (Year 8)	1984-10-10	1985-04-11	1985-10-11	$3760.00	Window Closed / Lapsed
11.5 Years (Year 12)	1988-10-10	1989-04-11	1989-10-11	$7700.00	Window Closed / Lapsed

Chemically strengthened opal glass

Abstract

Inventors

Bibliographic Details

Claims Analysis

References Cited (Backward Citations)

USPTO Annuity & Maintenance Windows

Assigned Categories & Tags

Assign Category Tag