High-index glasses that absorb UV radiation

• US 5,932,501 A
• Filed: 02/02/1998
• Issued: 08/03/1999
• Est. Priority Date: 10/18/1995
• Status: Expired due to Fees

• Current Assignee: Corning Incorporated
• Original Assignee: Corning Incorporated
• Inventors: Brocheton, Yves A. H.
• Primary Examiner(s): GROUP, KARL E
• Application Number:
  US09/011,166
• Time in Patent Office: 547 Days
• Field of Search: 501/64, 501/65, 501/67, 501/78, 501/903, 501/905, 501/56, 501/58, 501/59
• US Class Current: 501/64
• CPC Class Codes: C03C 14/006 the non-glass component being in the form of microcrystallites, e.g. of optically or electrically active material
• CPC Class Codes: C03C 3/068 containing rare earths
• CPC Class Codes: C03C 3/095 containing rare earths
• CPC Class Codes: C03C 4/085 for ultraviolet absorbing glass
• CPC Class Codes: Y10S 501/903 having refractive index less than 1.8 and ABBE number less than 70
• CPC Class Codes: Y10S 501/905 Ultraviolet transmitting or absorbing

Abstract

The invention relates to glasses which absorb UV radiation and which have the following composition, in wt. %: SiO₂ 30-52; ZnO 0-8; B₂ O₃ 12-22; PbO 0-2; ZrO₂ 5-14; Y₂ O₃ 0-15; Al₂ O₃ 0-12; La₂ O₃ 5-25; Li₂ O 1.5-3.5; TiO₂ 0-2; Na₂ O 0-6; HfO₂ 0-2; K₂ O 2-9; Nb₂ O₅ 0-2; MgO 0-5; Ta₂ O₅ 0-2; CaO 0-5; MoO₃ 0-2; SrO 0-9; WO₃ 0-2; BaO 0-14; SnO 0-4; Sb₂ O₃ 0-4; SnO₂ 0-4; AS₂ O₃ 0-4; CdO 0-1; CuO 0.15-1; F 0-2; Cl 0-3; Br 0-3; I 0-2 with the following conditions: Li₂ O+Na₂ O+K₂ O (X₂ O) 7-14; MgO+CaO+SrO+BaO (XO) 12-20; ZrO₂ +Al₂ O₃ <15; F+Cl+Br+I 0.2-4.0; TiO₂ +PbO+Nb₂ O₅ ≦2; AS₂ O₃ +Sb₂ O₃ +SnO₂ +SnO 0.05-4.0 and a ratio R=(M₂ O+2MO-Al₂ O₃ -ZrO₂)/B₂ O₃ where M₂ O and MO represent the total content of alkali metal oxide and the total content of alkaline-earth metal oxides, respectively, expressed in mol. %, between 0.50 and 1.00. Application to the manufacture of ophthalmic lenses, notably.

Claims

1. Essentially transparent nonphotochromic glasses with a refractive index of at least 1.58, presenting an abrupt cutoff at approximately 400 nm with respect to ultraviolet radiation, characterized by the following composition, expressed in weight percentages based on the oxides:

space="preserve" listing-type="tabular">______________________________________SiO.sub.2 30-52 ZnO 0-8B.sub.2 O.sub.3 12-22 PbO 0-2ZrO.sub.2 5-14 Y.sub.2 O.sub.3 0-15Al.sub.2 O.sub.3 0-12 La.sub.2 O.sub.3 5-25Li.sub.2 O 1.5-3.5 TiO.sub.2 0-2Na.sub.2 O 0-6 HfO.sub.2 0-2K.sub.2 O 2-9 Nb.sub.2 O.sub.5 0-2MgO 0-5 Ta.sub.2 O.sub.5 0-2CaO 0-5 MoO.sub.3 0-2SrO 0-9 WO.sub.3 0-2BaO 0-14 SnO 0-4Sb.sub.2 O.sub.3 0-4 SnO.sub.2 0-4As.sub.2 O.sub.3 0-4 CdO 0-1CuO 0.15-1 F 0-2Cl 0-3 Br 0-3I 0-2______________________________________

with the following conditions;

space="preserve" listing-type="tabular">______________________________________Li.sub.2 O + Na.sub.2 O + K.sub.2 O (X.sub.2 O) 7-14MgO + CaO + SrO + BaO (XO) 12-20ZrO.sub.2 + Al.sub.2 O.sub.3 <

15F + Cl + Br + I 0.2-4.0TiO.sub.2 + PbO + Nb.sub.2 O.sub.5 ≦

2As.sub.2 O.sub.3 + Sb.sub.2 O.sub.3 + SnO.sub.2 + SnO 0.05-4.0______________________________________

and a ratio R=(M₂ O+2MO-Al₂ O₃ -ZrO₂)/B₂ O₃ where M₂ O and MO represent the total content of alkali metal oxide and the total content of alkaline-earth metal oxides, respectively, expressed in mol %, between 0.50 and 1.00.

2. Glasses according to claim 1, characterized in that they are essentially free of CdO.

3. Glasses according to claim 1 or 2, characterized in that they have the following conposition:

space="preserve" listing-type="tabular">______________________________________SiO.sub.2 35-47 CaO 0-3B.sub.2 O.sub.3 12-19 SrO 0-7ZrO.sub.2 6.5-12 BaO 2-7Al.sub.2 O.sub.3 0-6 ZnO 0-3Li.sub.2 O 1.5-3 Y.sub.2 O.sub.3 0-12Na.sub.2 O 2-5 La.sub.2 O.sub.3 8-20K.sub.2 O 2-7 SnO 0.2-2.5CuO 0.25-0.75 Br 0.1-2Cl 0.1-2______________________________________

4. Glasses according to claim 1, characterized in that they are coloured by the addition of colouring agents and/or by a precipitate of copper colloids.

5. Lens characterized in that it consists of a glass as defined in any one of claims 1 to 4.