DE2248255B3 - - Google Patents

Description

Weight percent

SiO, 20-26

B ₁ O ₃ 2-8

BaO 20-38

MgO 0— ο

CaO 0-18

SrO 0-18

La ₂ O ₃ 20-32

Y ₂ O ₃ 0-25

ThO ₂ 0-18

F ₂ -O 2-7

or. _ . ,

Equivalcmpro / .cnl

Si _U2 0 42-53

B ₂₃ O 5-20

BaO 9-18

MgO 0-5

CaO 0-10

SrO 0-10

La _2/3 O 10-20

Y _2/3 0 0 20

Th ₁ , ₂ O 0-12

F ₂ -O 5-20

under the following conditions: SiO ₂ + B ₂ O ₃ = 26 --31 percent by weight b ^ w. Si ₁ , 2 O + B ₂ , O = 60-66 equivalent percent, BaO + MgO + CaO + SrO = 25-40 percent by weight or BaO + MgO + CaO + SrO = 10-22 equivalent percent, La ₂ O ₃ + Y ₂ O ₃ + ThO ₂ = 20-32 percent by weight or La _2/3 O + Y _{2 /;)} O + Th _1/2 O = 10-26 equivalent percent, the silica and boric acid content being the condition

[Si ₁₂ O] + [Β;, ©]

fulfilled, the fluorine content is at least 7 g / 100 cm ³ glass and the following high-refractive, weakly or moderately dispersing components can be included to set the desired optical positions and / or to improve the crystallization stability:

ZnO up to 6.6 percent by weight
ZrO, up to 7 percent by weight
Ta, O ₅ up to 12 percent by weight
Nb ₂ O ₅ up to 12 percent by weight

wherein the content of the ingredients La ₂ O ₃ , ThO ₂ , ZrO ₂ , BaO, SrO, CaO, ZnO, Ta ₂ O ₅ and Nb, O _{5 is} at least 60 percent by weight and 29 equivalent percent, respectively.

2. Optical glasses according to claim 1, characterized in that up to 25 percent by weight of La ₂ O _{3 are} replaced by Y ₂ O ₃ .

3. Optical glasses according to claim 1 or 2, characterized in that up to 7 percent by weight of the ThO ₂ content is replaced by ZrO ₂ .

4. Optical glasses according to one of claims 1 to 3, characterized in that they are used for adjustment of a desired η ,, - iy value up to contain a total of 8 equivalent percent of one or more of the following components:

CdO up to 10.4 percent by weight
PbO up to 10.8 percent by weight
A1_O ₃ up to 7 percent by weight
TiO ₂ up to 8 percent by weight
WO ₃ up to 7 percent by weight

35 The commercially available glasses in the optical position range of the LaK and LaF glasses have a Partial dispersion

4 ° ) J _t - / I,

45 the opposite of the normal partial dispersion, as it results from the Abbe equation

P _{9 f} = 0.6438 -0.001682 i> _d

calculated (see e.g. Schott catalog for optical glass No. 3050/1966/115 and Min-Kitalog 1968), considerable is decreased.

Glasses within the optical position range, which is due to the straight line connection of the following limit values is marked (Fig. 1)

n _d = 1.642 v _d = 58.0 to n _d = 1.699 v _d = 46.0

n _d = 1.642 r _d = 58.0 to n _d = 1.652 v " = 58.5

n _d = 1.652 v _d = 58.5 to n _d = 1.702 r _d = 54.6

n _d = 1.702 i _d = 54.6 to n _d = 1.742 v _d = 44.0

/ 1 ,, = 1.742 r _{l (} = 44.0 to / J ₁ , = 1.699 v _d = 46.0

: have particularly low P ₁₁ values. Additions of MgO. SrO. PbO, ZnO, CdO. TiO ₂ ,

The glasses with the lowest P ₁₁ values and fts Al ₂ O. Nb ₂ O ₅ , Ta ₂ O ₅ , WO, are used to vary the

! extreme optical positions (e.g. / i ,, = 1.697: ι · ,, = 55.4) / 1 ,, - and iy values as well as to improve the crisis

: are essentially composed of B ₂ O, + CaO + La ₂ O, stable to installation and chemical resistance

- ZrO ₂ + <IO weight pro / ent'SiO ,. "speed.

An increase in the SiO ₂ content above 10 percent by weight at the expense of the B ₂ O ₃ led to a reduction in the size of the glass area, thus increasing the tendency towards crystallization and, at the same time, reducing the ο ,, value for a given n ^ value. This tendency could be counteracted by partially replacing CaO with BaO and La ₂ O ₃ with ThO ₂ , but the υ ,, - _{value remained lower, and the P jf} values are nevertheless far below the normal value already mentioned (F i g. 2).

The equivalent ratio

[SiT ₁ OJ

[Si ₁₂ O] ₊ [B ₁₂ O]

is <0.60 for all known glasses of this group. It has now been found that it is surprisingly possible, without the disadvantage of the noticeable reduction in the P _{9 F} value, to also greatly enlarge the glass area by changing the equivalent ratio

[Si ₁₂ O] _ [Si,, 0] + [B ₂₂ O]

increases to at least 0.62 while replacing at least 5 equivalent percent of the oxygen with fluorine.

The invention relates to optical glasses with improved, different partial dispersion

percent, the content of silica and boric acid the condition

^ 0.62

^P °> ~ n _F -n _c

in the optical position range of the lanthanum crown and lanthanum flint glasses, characterized by the following composition

Weight percent

SiO ₁ 20 26

B ₂ O " ₃ 2 8

BaO 20 38

IVIaO O- 6

CaO 0 18

SrO 0-18

La ₂ O ₃ 20-32

Y ₂ O ₃ 0-25

ThO ₇ 0 18

F ₂ -O 2- 7

Eqiiivalcntpro / enl

Si ₁₁ 0 42 53

B ₁₃ 0 5 20

BaO 9 18

MgO 0 5

CaO 0 10

SrO 0 IO

La ₁₃ 10 20

Y ₂ ", 0 20

TIi ₁₁ 0 0-12

F ₁ " ^: O 5 20

under the following conditions: SiO ₁ + B ₂ O ₃ = 26 31 percent by weight or Si ,,, + B ₂₃ O = 60 66 equivalents / percent !. BaO + MgO 4- CaO + SrO = 25 40 percent by weight or BaO + MgO + CaO + SrO = H) 22 equivalent percent. La ₂ O, + Y ₁ O, + ThO ₂ = 20 32 percent by weight or La ₁₃ O + Y ₁ ,, O + Th ₁₁ O = 10 26 equivalent-

[Si _{1 2} O] +

fulfilled, the fluorine content is at least 7 g / 100 cm ³ glass and the following high-refractive, weakly or moderately dispersing components can be included to set the desired optical positions and / or to improve crystallization stability:

ZnO up to 6.6 percent by weight
ZrO ₂ up to 7 percent by weight
Ta ₂ O ₅ up to 12 percent by weight
Nb ₂ O ₅ up to 12 percent by weight

wherein the content of the constituents La ₂ O ₃ , ThO- ,, ZrO ₂ , BaO, SrO, CaO, ZnO, Ta ₂ O ₅ and Nb ₂ O _{3 is} at least 60 percent by weight or 29 equivalent percent.

The symbolism F ₂ -O means: content of fluorine after subtracting the oxygen replaced by this fluorine: ieF ₂ - O <2 -7 percent by weight means: In a fictitious, purely oxidic glass of the composition range mentioned, as much oxygen should be replaced by two fluorine that the additional weight is 2-7 g per 100 g of the oxidic glass.

La ₂ O ₃ can be partially or completely replaced by Y ₂ O ₃ ; Up to 7 percent by weight of the ThO ₂ content can be replaced by ZrO ₂ , and the following more strongly dispersing components can be contained up to a maximum of 8 equivalent percent or in the following percentages by weight:

CdO up to 10.4 percent by weight
PbO up to 10.8 percent by weight
Al ₂ O ₃ up to 7 percent by weight

TiO ₂ up to 8 percent by weight
WO ₃ up to 7 percent by weight

The fluorine content can be stirred into any of the compounds customary or possible in glass melting technology (e.g. as BaF ₂ , LaF; ,, ThF ₄ , BaSiF _h etc.).

0 2 equivalent percent As ₂ O ₃ , Sb ₂ O ₃ , NaCl, NH ₄ NO ₃ , alkali silicofluorides, etc. can be used as refining agents.

In Tables 1 and 2 are examples of the invention Glasses shown in percentages by weight or equivalent percentages.

F i g. I shows the optical position range of the invention Glasses;

F i g. 2 the dependency
55

- n,

= P "

from

known glasses and the glasses according to the invention.

In these figures, the crosses indicate the invention Glasses. The other markings correspond to commercial LaK and LaF glasses. the with the specified numbering can be found in the glass catalogs.

F i g. 2 shows that the glasses according to the invention, with the same optical position , have a higher partial dispersion P ₁₁ than the previously known glasses of the same type

optical location. This improvement is even more noticeable in the partial dislocation

(see Tab. 2).

The glasses according to the invention have very good resistance to changes in climatic conditions (WKB Kl. 1-2), good Acid resistance (Class f4-5a) and low susceptibility to staining (Class 1–3). The glasses can be opened as usual Grinding, polishing and pressing of silicate glasses.

Melting example 3

melted and 2 hours at 152O ° C purified Then the temperature is zurückgenommei and abgerührt of about 1420-1030 ⁰ C. The pouring takes place at around 980 ° C in a preheated casting mold. The reproducibility of the optical values is guaranteed by a melting unit that is as closed as possible, with which the fluorine evaporation can be controlled and influenced. These conditions also apply to the following example:

Melting example 14

Oxides Weight raw materials : Weighing in for Oxygen through ι 1460 to 1480 ° C in a platinum crucible 1 50.8 2 50.2 3 4 - Oxides 15th SiO ₂ Weight 50.6 raw materials - Weighing in for percent 4.6 kg 14.6 14.4 44.2 49.4 10.9 14.3 20 B ₂ O ₃ percent 14.5 15.4 14.7 4.6 kg melt 13.8 (Compositions in equivalent percent) 19.3 14.3 BaO 2.0 3.2 melt in g 3.1 in g SiO ₂ 20.75 SiO ₂ 921.1 Si _1/2 O 24.6 SiO ₂ 1133.6 B ₂ O ₃ 7.00 H ₃ BO ₃ 549.6 bJo 153 13.4 18.3 15.9 La ₂ O ₃ 5.3 14.0 H ₃ BO ₃ 14.2 13.1 449.4 BaO 26.08 BaF ₂ 1329.1 These raw materials are mixed well. The mix MgO TiO ₂ 33.5 BaCO ₃ 308.4 La ₂ O ₃
ThO ₂ 31.12
15.05 La ₂ O ₃
ThO ₂ 1395.7
668.3 will be at about CaO ThO ₂ Ba (NO ₃ J ₂ 394.5 Table 1 SrO BaF ₂ 1228.2 Sum of
Oxides 100.00 BaO 16.9 total 28.8 13.8 La ₂ O ₃ . 1338.2 PbO 7.3 3.0 5.2 TiO ₂ 3.1 3.1 244.8 F ₂ -O 3.74 = More weight through Aus ZnO F ₂ -O 2.6 ThO ₂ 119.8 exchange of CdO fluorine U ₂₃ O 35 total 100.0 Gfcs.-total 103.74 Y ₂₃ O 3.1 5.1 As ₂ O ₃ as 7.1 Al ₂₃ O Refining agents 3.3 As ₂ O ₃ as 0.30 Zr, ₂ O Refining agents Ti ₁₂ O 103.3 Th ₁₂ O 5 6 0.3 13.8 Nb ₂ , 0 50.2 51.6 Ta,, O 14.4 14.9 7th 8 9 10 3.5 50.8 51.3 50.1 12.9 13.1 14.5 14.6 14.2 - ] f) .O 15.2 13.6 5.1 14.0 3.0 5.2 3.0

CaCa ** O Ci \ J \ J

continuation 1 2 3 4th 5 6th 7th 8th 9 10 100.0 100.0 100.0 100.0 100.0 100.0 100.0 100.0 100.0 100.0 total 15.3 13.4 10.9 15.2 15.6 13.1 14.1 9.3 9.4 9.3 F ₂ -O 0.3 0.3 0.3 0.3 0.3 0.3 0.3 0.3 0.3 0.3 As ₂ O ₃ chimes 0.78 0.78 0.70 0.77 0.78 0.77 0.78 0.78 0.78 0.78 Si _1/2 O 34.6 35.4 36.5 33.2 35.4 33.5 34.9 32.7 42.2 35.7 (Si " ₂ O) + (Β ,, -, Ο) 0 0 0 3.1 0 0 0 6.8 3.2 0 Σ liochbr., Black.
disp. Fabrics Σ strongly disn. Fabrics

Table 1 (continued)

Si _W2 0 B ₂ ^ o

MgO CaO SrO BaO

PbO ZnO CdO

La _2/3 O Y ₂ , OK A1 _2/3 O

12th

13th

51.2 14.4

15.6

7.5 8.2

50.2 14.0

13.9

15.6

14th

48.6 13.6

13.0

! 5.7

15th

43.2 18.8

10.6

15.6

16

17th

50.3
14.5

15.3

16.2

49.4
14.5

14.4

16.1

Table 1 (continued)

20th

21

22nd

23

24

25th

27

18th

50.8 14.5

14.4

0.3 0.3

16.2

28

19th

49.6 14.3

15.1

15.8

Zr, _{/ 2} O
Ti _1/2 O
Th " ₂ O 7.2 3.1 6.3 7.9
1.2 7.1 2.1 3.1 0.5
3.1 3.1
2.1 Nb _2/5 O 4.7 2.5 W ₁₃ O 1.6 total 100.0 100.0 100.0 100.0 KM) ₁ O 100.0 100.0 100.0 100.0 F ₂ -O 6.2 9.4 9.0 9.0 6.2 15.2 14.4 14.4 15.0 As ₂ O ₃ chimes 0.3 0.3 0.3 0.3 0.3 0.3 0.3 0.3 0.3 Si _1n O 0.70
37.2 0.78
34.4 0.78
35.9 0.7S
29.9 0.70
38.0 0.78
33.6 0.77
36.1 0.78
34.6 0.7; ISi, _{/ 2} O) + (B ₂ J ₃ Ol
Σ high br .. black disp. Fabrics 0 0 0 7.9 0 1.6 0 0.3 33.0 Σ strongly disp. Fabrics 3.1

29

Si ₁₂ O
B ₂₁₃ O 49.8
13.9 49.4
14.3 50.9
14.5 43.0
18.8 41.4
19.0 4Z9
18.8 41.9
18.3 44.6
19.5 41.5
18.1 44.9
16.9 MgO
CaO
SrO
BaO 13.8 13.2 5.1
10.2 10.5 10.7 10.6 10.2 11.0 10.2 IU PbO
ZnO
CdO 0.6 5.2

509 519/31

continuation

M-O

10

20th

21

22nd

La _2/3 O

A1 ₂ , ₃ O Zr " ₂ O

Ta _{2; 5} O W ₁₃ O sum

As ₂ O ₃ lamb.

Si " ₂ O (Si _1/2 O) + (B _2n O)

Σ high br., Black disp. Fabrics

Σ strongly disp. Fabrics

15.5

5.9 1.1

100.0 8.9 0.3

0.78 36.3

16.0

100.0 9.2 0.3

0.77 31.3 5.0

16.3

3.0

100.0
9.3
0.3

0.78
34.6

23
17.9

1.0

0.5 0.8 7.1

24

25th

100.0 10.5 0.3

0.70 36.0

2.2

18.1

5.7 4.9

100.0 10.7 0.3

0.68 39.4

17.8

3.2 6.1

100.0 10.6 0.3

0.69 34.5 3.2

26th
13.5

27

6.9

9.1

100.0
6.0
0.3

0.70
39.7

12.3

7.3

100.0
11.0
0.3

0.70
30.6
5.2

28
11.6

6.9

100.0
10.2
0.3

0.70
40.4

29
18.0

100.0 16.3 0.3

38.2

Table (percent by weight)

SiO ₂ B ₂ O ₃

MgO CaO SrO BaO

PbO ZnO CdO

La ₂ O ₃

Y ₂ O ₃

Al ₂ O ₃

ZrO ₂ TiO ₂ ThO ₂

Nb ₂ O ₅ Ta ₂ O,

WHERE ₃

23.9 5.3

36.7

27.7

23.5 5.2

32.0

28.8

20.8
7.0

26.1

31.1

23.8 5.3

2.0

34.9

27.7

23.8 5.3

5.7 31.3

27.6

6.4

10.5

15.0

6.3

6.3

24.9 5.5

32.2

26.4

11.0

23.6

5.2

33.4

23.1

14.7

23.2
5.1

35.4
6.8

23.4

6.1

23.2
5.1

33.4
10.8

21.4

6.1

10

24.2 5.3

33.0

24.5

F ₂ -O 5.3. 4.6 3.7 5.4 5.3 4.6 4.8 2.9 2.9 3.1 Total 105.3 104.6 103.7 105.4 105.3 104.6 104.8 102.9 102.9 103.1 As ₂ O, chime. 0.3 0.3 0.3 0.3 0.3 0.3 0.3 0.3 0.3 O.; Σ high br .. black
disp. Fabrics 70.8 71.3 72.2 68.9 71.9 69.6 71.2 64.9 60.9 70 ,: ν strongly disp. Fabrics 0 0 0 10 0 0 0 6.8 10.8 0 r « 1.6560
58.08 1.6764
56.32 1.6906
55.47 1.64683
57.95 1.65726
57.36 1.66801
56.54 1.67050
56.81 1.68076
51.22 1.68369
49.19 ll
55th!

862

11th

12th

continuation

- * · -— - 0.5491 0.5502 0.5504 0.5495 0.5500 0.5518 0.5498 η, -; ΐ,

"« - "-'- ■ - 1.0087 1.0102 1.0104 1.0091 1.0100 1.0119 1.0098

Table 2 (continued)

0.5512

0.5500

0.5521

0.5666

0.5564

0.5529

1.0137

0.5531

1.0139

0.5500

1.0098

0.5600 0.5491

11th - 12th - 13th 14th - 15th - 16 - 17th - 18th - _ 19th - SiO ₂ 20.8 25.3 ._ 24.9 24.7 - 20.8 23.8 - 23.4 - 23.8 - 27.6 23.8 - B ₂ O ₃ 7.0 - 5.5 39.0 5.4 5.5 33.1 7.0 - 5.3 - 5.3 - 5.3 34.9 - 5.3 - MgO 26.1 26.1 37.0 35.0 1.1 - 37.1 CaO - 0.5 SrO - - · - - - BaO _ 13.3 35.2 28.8 - - - .__ PbO 27.1 10.1 27.1 27.6 27.7 27.5 ZnO 4.0 - - - - - - CdO _.- - - - - La ₂ O ₃ 28.1 Y ₂ O ₃ Al ₂ O ₃ .-

ZrO ₂
TiO ₂
ThO ₂ 15.0 2.2 6.8 6.4 - 3.3 5.3
2.6 - 3.2 15.0 4.4 - 1.9 6.5 - 5.0 0.5
6.3 - 5.0 2.0
4.3 - 5.3 Nb ₂ O ₅
Ta ₂ O ₅ - 102.2 - 103.3 - 103.2 4.0 5.3 2.1 105.0 - 105.0 105.3 WHERE ₃ - 0.3 0.3 0.3 105.3 0.3 0.3 0.3 F ₂ -O 72.2 3.2 69.7 64.5 Z3 0.3 71.3 69.8 68.9 Total 0 103.2 0 5.3 102.3 69.0 0 1.1 2.0 As ₂ O ₃ chime 1.70571
53.87 0.3 1.67777
53.54 1.69932
47.06 0.3 1.9 1.67350
54.53 1.65717
56.84 1.6772
52.44 Σ high br., Scliw.
disp. Fabrics 69.2 72.2 1.66717
55.33 Σ strongly disp. Fabrics 0 0 1.65876
56.53 1.71589
50.41

Table e 2 (continued) 21 22nd 23 24 25th 26th 27 28 29 20th 24.5 24.9 20.4 19.7 20.3 20.6 20.7 20.7 21.0 SiO ₂ 24.4 5.5 6.9 7.0 6.9 6.9 7.0 7.0 6.1 B ₂ O ₁ MgO CaO 8.6 SrO ' 33.4 25.5 25.4 26.1 25.6 25.8 26.1 26.1 26.8 BaO 34.5 2.0 _ PbO ZnO iod CdO

ti ».

862

continuation

La ₂ O ₃

13th

Al ₂ O ₃

ZrO,
TiO, "
ThO,

Nb ₂ O ₅
Ta ₂ O ₅

WHERE ₃
F ₂ -O
Ges.-Sumrne
As ₂ O ₃ chime

Σ high br., Black
disp. Fabrics

Σ strongly disp. Fabrics

273

6.0 23

21

3.2 103 ^

03 70.3

1,676 ?! 53.92

0.5513

28.7

3.3 4.6

3.3 103.3

0.3 66.7

3.3

1.68671 50.72

23

303

0.5

0.5

103.6

0.3

71.2

24

3.7

103.7

03

733

25th

30.5

3.7
103.7

03
68.8

4.0

26th

23.9

03 - - 2.0 - 0.5 - 12.7 - 14.8 11.9 _ 14.9 4 ⁷ 7.9

2.2

102.2

03

72.5

14th

1.66573 1.69690 1.71202 1.70668 1.73292
56.42 53.6! 50.60 50.05 46.71

0.5529

27

20.8

15.0

3.7
103.7

0.3
61.9

10.4

20.8

15.0 10.4

3.7

103.7

0.3

72.3

29

5.6 105.6

1.70976 1.74243 1.68816 51.66 44.58 53.76

For this purpose 2 sheets of drawings

Claims (1)

Patent claims: 1. Optical glasses with improved deviating partial dispersion ^e - ^F n _F -n _c marked in the optical position of the lanthanum crown and lanthanum flint glasses through the following composition range