|국가/구분||United States(US) Patent 등록|
|미국특허분류(USC)||351/159 ; 351/166 ; 351/177 ; 65/30E|
|발명자 / 주소|
|출원인 / 주소|
|인용정보||피인용 횟수 : 15 인용 특허 : 0|
An ophthalmic glass lens can be prepared by exposing an alkali metal silicate glass to an ion exchange process in which the glass is chemically strengthened by an exchange of potassium ions for sodium ions in the surface layer of the lens at a temperature either above or below the strain point of the glass. The glasses prepared are essentially free of alumina, have adequate strength and substantially increased depth of pentration of the neutral zone even when up to about 6 percent lime is utilized in the preparation of the glass. The effect of lime as a ...
A chemically-strengthened ophthalmic glass lens having a compressively-stressed ion-exchanged surface zone that is at least 60 microns in depth, said lens being formed from a silicate glass comprising by weight about 3 to about 11 percent sodium oxide, about 7 to about 15 percent potassium oxide, up to about 5 percent of other alkali metal oxides, about 12 to about 20 percent of a total of sodium and potassium oxides and other alkali metal oxides, a minimum of 3 to about 6 percent of calcium oxide, the calcium oxide being balanced by an amount of about 3...