SHELLAC EPC

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 1.520^a 1.520^a 1.4976

Temperature coefficient -0.000112 to 0.000210^b -0.000200^c ------ 0.000167^d -0.000400^c

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-


3,200
6,400
3,200
3,400
3,300
2,500
-------

1,100

-------

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...

Kg/cm²

-do-

------

13.5X10³

11.50 X10³

Ultimate tensil strength at 20°C...

Kg/cm²

132

------

Ultimate tensile by Michael's machine

Lb./sq.in

275-394

------

Abrasion resistance (sand)....

110

------

-----

Hardness

Scratch (1mm. Ball) on copper....

Shere.....

Brinell.....

Vickers......

Kg.

-----

4.5-5.5

60-61

18.1-19.1

16.2-17.0

2.0-2.5

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 51^CC

1.03

11%shellal- bonded micatube at 62⁰C

1.20

Thermal expansion (cubical)

At -80⁰ to 46⁰ C......

At 46⁰Cto^.....

Per⁰C

a=2.73X10^-4

b=0.39X10^-6

Thermal resistivity, desiccated samples

At 33° C

At 27° C

At 35° C - 27.9° C

At 29° C

c.g.s

-do-

359

400

------

429

------

490

511

------

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

394

------

421 - 414

------

-----

387 - 400

Fluidity at 70° C

At 57° C

Rho

2X10^-6-200X10^-8

1X10^-8

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......

° C

40 - 50

80 - 50

85 - 86.6

65 - 70

Melting point

By mercury

77 - 90

77 - 80

Flow

Westinghouse apparatus

V - tube apparatus

A.S.T.M apparatus

Sec.

mm.

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