|
TABLE I
General Physical Properties
| VALUES |
| Properties
|
Unit |
Shellac |
Dewaxed
Shellac |
Bleached
Lac |
Pure
or hand resin |
Soft
resin |
| Specific
gravity
|
|
1.143
- 1.207 |
|
1.110
- 1.196 |
1.028
- 1.031 |
1.028
- 1.029 |
| Refractive
index at 20°C
|
|
1.5210-
1.5272 |
1.5228 |
1.520a
|
1.520a
|
1.4976 |
| Temperature
coefficient
|
|
-0.000112
to
0.000210b
|
-0.000200c
|
------ |
0.000167d
|
-0.000400c
|
| Molar
refraction
|
|
------ |
------ |
------ |
495 |
137 |
| Viscous
Volume
|
ml. |
------ |
7.623X10-18
|
------ |
45.6
X
10-18
|
7.56X10-18
|
| Molecular
Volume
|
ml. |
------ |
1.59
X 10-21
|
------ |
2.69
X 10-21 |
0.97
X10-21
|
| Energy
of activation of viscous
Flow, E0 of
molten lac
|
|
28.74
|
38.13
|
------ |
31.61
- 33.34
|
25.32
- 47.67
|
| Molar
axial ratio
|
|
------ |
10.3
|
------ |
11.3 |
7.8 |
| (a)
at 23° C;(b) at 20-40° C;(c) at 20-30° C;(d) at
20-50° C;(e) at 20-90° C
|
TABLE II
Mechanical Properties
| |
|
|
|
|
|
|
| Properties |
Unit |
Shellac |
Dewaxed
Shellac |
Bleached
Lac |
Pure
or hand resin |
Soft
resin |
| Adhesion |
| To
Steel....... |
| On
optically Plane surface... |
| In
tension...... |
| In
sheet....... |
| To
copper...... |
| To
brass...... |
| To
glass...... |
|
| |
| Lb/sq.in |
|
-do- |
| -do- |
| -do- |
| -do- |
| -do- |
| |
|
| |
| 3,200 |
| 6,400 |
| 3,200 |
| 3,400 |
| 3,300 |
| 2,500 |
| ------- |
|
|
|
|
|
|
Velocity
of sound at 20° C...... |
Metres/sec |
------- |
|
970 |
------- |
------- |
| Modules
of elasticity |
| By
sound transmission at 19.4° C..... |
| By
Bean method at 15-20° C... |
|
|
|
|
|
|
|
|
Ultimate
tensil strength at 20°C...
|
Kg/cm2
|
132 |
|
------ |
|
|
|
Ultimate
tensile by Michael's machine |
Lb./sq.in |
275-394 |
|
------ |
|
|
|
Abrasion
resistance (sand).... |
|
110 |
90 |
------ |
------ |
----- |
| Hardness |
| Scratch
(1mm. Ball) on copper.... |
| Shere..... |
| Brinell..... |
| Vickers...... |
|
|
| |
| 4.5-5.5 |
| 60-61 |
| 18.1-19.1 |
| 16.2-17.0 |
|
|
|
|
|
TABLE III
Thermal properties
| VALUES |
| Properties |
Unit |
Shellac |
Dewaxed
Shellac |
Bleached
Lac |
Pure
or hand resin |
Soft
resin |
| Specific
heat at 100-400C |
Cal/cm/0c
|
0.36-0.38
|
|
|
|
|
| Specific
heat at 450-400C |
|
0.56
|
|
|
|
|
| Heat-hardened
shellac at 450-500C |
|
0.25 |
|
|
|
|
| Thermal
conductivity at 300C |
M.W./cm/0C
|
2.42 |
|
|
|
|
| Thermal
conductivity at 350C |
|
2.09 |
|
|
|
|
| 19%shellal-
bonded micatube at 51CC |
|
1.03 |
|
|
|
|
| 11%shellal-
bonded micatube at 620C |
|
1.20 |
|
|
|
|
| Thermal
expansion (cubical) |
| At
-800
to
460 C...... |
| At
460Cto..... |
|
|
|
|
|
|
|
| Thermal
resistivity, desiccated samples |
| At
33° C |
| At
27° C |
| At
35° C - 27.9° C |
| At
29° C |
| At
29° C |
|
| |
|
c.g.s |
| -do- |
| -do- |
| -do- |
| -do- |
|
|
|
|
|
|
| Thermal
resistivity, samples water |
| Immersed
for 24 hours |
| At
27° C - 35.8° C |
| At
27.4° C - 36.1° C |
| At
28.6° C - 32.5° C |
|
|
|
|
|
|
|
| Fluidity
at 70° C |
| At
57° C |
|
|
|
|
|
|
|
| Softening
range (Tf-Tg) |
°
C |
40-50 |
|
|
|
|
| Time
of phymerisation at 150° C |
min. |
30
- 120 |
|
|
|
|
| Softening
point |
| By
Nagel's method... |
| By
modified Durran's method.... |
| By
mercury surface method...... |
|
|
| 40
- 50 |
| 80
- 50 |
| 85
- 86.6 |
| 65
- 70 |
|
|
|
|
|
|
|
|
|
|
|
|
|
| Flow |
| Westinghouse
apparatus |
| V
- tube apparatus |
| A.S.T.M
apparatus |
|
|
| |
| 55
- 480 |
| 84
- 17 |
| 7100
- 45 |
|
|
|
|
|
TABLE IV
Electrical Properties
| |
|
|
|
|
|
|
| Properties |
Unit |
Shellac |
Garnet
Lac |
Dewaxed
Shellac |
Pure
or hand resin |
Soft
resin |
|
Volume
resistivity of film from Alcoholic solution, at
30° C..... |
" |
1.2
x 1016
|
|
|
|
|
|
Surface
resistivity of film from Alcoholic solution, at
20% humidity..... |
ohms. |
2.2
x 1014 |
|
|
|
|
|
Surface
resistivity of film form Alcoholic solution, at
40% humidity..... |
" |
1.1
x 1014 |
|
|
|
|
|
Electric
strength, at 20° C |
Volts/ml. |
420
- 1,550 |
|
416 |
|
|
|
Electric
strength, at elevated temp. or High
humidity....stop test..... |
"
" |
900
- 1200
277 |
|
|
|
|
|
Dielectric
strength.... |
Volts/cm. |
200-400
x 103 |
140-180
x 103 |
|
|
|
|
Dielectric
strength of film.. |
" |
360-480
x 103 |
|
|
|
|
|
Dielectric
constant at infinite .... frequency |
e.g.s.
elec.
Trostatic
Units. |
3.6 |
|
|
|
|
|
50
C/S at 30° - 90° C....
1 KC/S at 30° - 90° C....
10 KC/S at 30° - 90° C....
100 KC/S at 30° - 90° C... |
"
"
"
" |
3.91
- 7.85
3.63 - 7.36
3.57 - 6.46
3.48 - 5.42 |
------
------
------
------ |
------
------
------
------ |
3.90-8.13
3.85-7.37
3.76-6.60
3.85-5.97 |
5.80-5.87
4.70-8.90
4.23-6.36
3.96-8.00 |
|
Dielectric
loss at 1 KC/S and 30°-90° C...... |
c.g.s.
electrostac
units |
0.026
- 0.329 |
------ |
------ |
0.028-0.410 |
0.282-0.128 |
|
Dielectric
loss at 50 C/S and 30°-90° C..... |
------ |
0.020
- 0.435 |
------ |
------ |
0.020-0.153 |
0.460-0.262 |
|
Surface
flashover strength of varnish, at 60% humidity.... |
Volts./cm. |
6.2
x 103 |
------ |
------ |
|
|
|
Power
factor at 20° C.... |
tan
q
|
0.001-0.0072 |
------ |
------ |
|
|
|
Loss
factor..... |
K
tan q
|
0.0152-0.0230 |
------ |
------ |
|
|
|
Permittivity |
----- |
2.3
x 3.8 |
------ |
------ |
|
|
|
Dipole
moment |
Deleyes |
------ |
------ |
------ |
|
|
|
Magnetic
susceptibility |
c.g.s.
electro - magnetic unit |
-0.30
x 10-6
|
|
|
|
|
TABLE V
| CHEMICAL CONSTANTS |
| Constants |
Shellac |
Bleached
Lac |
Pure
or hand resin |
Soft
resin |
| Acid
value |
65.75 |
73
- 118 |
55
- 60 |
103
- 110 |
| Saponification
value |
220
- 230 |
176
- 276 |
218
- 225 |
207
- 229 |
| Ester
value |
155
- 165 |
103
- 158 |
163
- 165 |
104
- 229 |
| Hydroxyl
number |
250
- 280 |
------ |
235
- 240 |
116
- 117 |
| Iodine
Value : |
| Wijs'
(1 hr)..... |
| Hiibl's...... |
| By
hydrogen absorption..... |
| Thiocyanogen
number...... |
|
| |
| 14
- 18 |
| 8
- 12 |
| 23
- 25 |
| 18
- 20 |
|
| |
| 10
- 11 |
| ------ |
| ------ |
| 9
- 11 |
|
| |
| 11
- 13 |
| ------ |
| 13
- 16 |
| ------ |
|
| |
| 50
- 55 |
| ------ |
| 50
- 60 |
| ------ |
|
|
Carbonyl
value :
Sodium sulphite method.....
Hydroxylamine hydrochloric method..
Alkaline hydrogen peroxide method.. |
7.8 - 27.5
16 - 23
35 - 65 |
------
------
------ |
17.6*
------
------ |
17.3*
------
------ |
|
Molecular
weight :
By Rast's method.....
By osmotic presure.....
By acid value and basicity....... |
1006
------
------ |
949
------
------ |
1900 - 2000
1800 - 1857
1918 - 1932 |
|
|
*corrected
values |
PHYSICAL AND CHEMICAL CONSTANTS OF
SHELLAC
U.S.S.I.A's Specifications
| |
Hot
Alcohol Insoluble |
Water
Soluble |
Ash |
Orpiment
As2 S3 |
Moisture |
Wax |
Iodine
No. |
Acid
No. |
Saponi-
fication No. |
Ester
No. |
Hydroxyl
No. |
Specific
Gravity |
Refra-
ctive Index |
| |
(3,4) |
|
|
|
|
|
|
(5) |
(5) |
(5) |
(5) |
|
|
| Orange Flaked Shellac(6) |
% |
% |
% |
% |
% |
% |
|
|
|
|
|
|
|
| U.S.S.A.T.N.(1) |
3.00 |
0.50 |
1.00 |
0.1-0.4 |
2.00 |
5.5 |
24.3 |
70-80 |
225-232 |
150-155 |
250-260 |
|
|
| T.N.Pure |
3.00 |
0.50 |
1.00 |
0.1-0.3 |
2.00 |
5.5 |
18.0 |
70-75 |
225-228 |
150-155 |
260-270 |
1.207 |
|
| U.S.S.A.T.N. |
3.00 |
0.50 |
1.00 |
0.1-0.3 |
2.00 |
5.5 |
18.0 |
70-75 |
225-228 |
150-155 |
260-270 |
1.207 |
|
| Heart |
2.50 |
0.50 |
1.00 |
0.2-0.7 |
2.00 |
5.5 |
18.0 |
70-75 |
226-230 |
155-160 |
270-280 |
|
|
| Fine |
2.50 |
0.50 |
1.00 |
0.2-0.7 |
2.00 |
5.5 |
18.0 |
70-75 |
226-230 |
155-160 |
270-280 |
|
|
| Superfine |
1.75 |
0.50 |
1.00 |
0.1-0.5 |
2.00 |
5.5 |
18.0 |
70-75 |
226-231 |
155-165 |
280 |
|
1.516 |
| Pale Orange(2) |
1.00 |
0.50 |
1.00 |
0.1-0.2 |
2.00 |
5.5 |
18.0 |
68-75 |
231 |
160-165 |
|
|
|
| Bleached Shellac |
|
|
|
|
|
|
|
|
|
|
|
|
|
| Dry |
1.00 |
1.00 |
1.00 |
0.0 |
6.00 |
5.5 |
10.0 |
90-95 |
260 |
160 |
|
1.196 |
1.534 |
| Dry Refined |
0.20 |
0.30 |
0.30 |
0.0 |
6.00 |
0.2 |
10.0 |
105-115 |
275 |
165 |
|
1.217 |
|
| Seed Lac |
|
|
|
|
|
|
|
|
|
|
|
|
|
| Koosmie |
3.00 |
1.00 |
1.00 |
|
2.00 |
5.0 |
16.0-18.0 |
70 |
220-225 |
150-155 |
|
|
|
| Bisacki |
5.00 |
1.00 |
2.00 |
|
2.00 |
5.5 |
18.0 |
70 |
220-225 |
150-155 |
|
|
|
| Garnet Lac |
0.50 |
0.50 |
0.30 |
|
2.00 |
0.1-3.5 |
18.0-40.0 |
|
190-225 |
|
280 |
|
|
| Button Lac |
0.1-1.0 |
0.30 |
0.30 |
|
2.00 |
4.00 |
18.0 |
|
|
|
220-270 |
|
|
history of shellac
| lac to shellac | properties
of shellac | application
|
