Processing of video discs

High density information discs, such as video discs, which have been treated with a fluorinating agent become resistant to and stable under conditions of high temperature and high relative humidity, even after exposure to such conditions for extended periods of time. The treatment with the fluorinating agent is accomplished by use of a bath of an aqueous solution of a "soft" fluorinating reagent, such as fluorosilicic acid or fluoroboric acid.

This invention relates to the manufacture of high density information 
discs, also known as video discs. More particularly, this invention 
pertains to the improved manufacture and processing of such discs to 
improve their storage stability, and particularly their stability or 
resistance to conditions of high temperature and high relative humidity. 
BACKGROUND OF THE INVENTION 
Martin et al., in U.S. Pat. No. 4,228,050, have disclosed an improved 
molding composition for the compression molding of high density 
information discs, also known as video discs. This molding composition is 
a conductive molding composition, containing sufficient conductive carbon 
black particles to obtain the desired conductivity (bulk resistivity below 
about 500 ohm-cm at 900 megahertz), along with other desired additives 
such as stabilizers, lubricants, plasticizers, and processing aids. The 
remainder of the conductive molding composition is a polyvinylchloride 
based resin, and the composition has the proviso that not more than about 
5 percent by weight of liquid additives are present therein. Molded 
articles, such as high density information disc replicas, molded from this 
improved conductive molding composition are said to be dimensionally 
stable and possess improved resistance to the effects of changes in 
environmental temperatures and humidity. 
However, we have found that the stability of these discs with respect to 
environmental fluctuations of temperature and relative humidity have been 
less than satisfactory. Discs which on initial playback have excellent or 
acceptable playback characteristics, deteriorate with respect to playback 
after storage under ambient conditions. This deterioration is particularly 
marked when the discs are exposed to conditions of high temperature and 
high relative humidity. 
Huck et al. in copending application Ser. No. 091,878, filed Nov. 7, 1979, 
and entitled "VIDEO DISC PROCESSING" have disclosed that high density 
information discs which have been cleaned with an aqueous solution have 
improved stability of playback characteristics to changing environmental 
conditions. The use of water alone or dilute solutions of acids or bases 
are shown to remove water soluble metal salts and other water soluble 
materials, such as certain organic impurities, on the surface of the disc, 
which materials contribute to the moisture sensitivity of the disc. 
Datta, in copending application Ser. No. 109,206, filed Jan. 4, 1980, 
entitled "VIDEO DISC PROCESSING", has disclosed that an aqueous solution 
comprising an oxidizing agent, a base, and a sufficient amount of a 
fluorosurfactant which will produce a solution having a surface tension 
below about 35 dynes/cm.sup.2 is an excellent cleaning solution for high 
density information discs. It has been shown that by the use of this 
aqueous cleaning solution, metal salts including calcium, barium, nickel, 
lead, and tin salts, sulfur compounds, and organic compounds, such as 
esters, which are originally present on the surface of the disc are 
removed from the disc surface, thereby lessening its sensitivity to 
moisture. 
However, upon exposure to conditions of elevated temperature and relative 
humidity for extended periods of time, the discs deteriorate such that 
their playback characteristics are no longer excellent and in some cases 
are not even acceptable. Thus, the search has continued for better disc 
materials and processing to improve the stability of high density 
information discs to conditions of high temperature and high relative 
humidity, particularly exposure to such conditions for extended time 
periods. 
SUMMARY OF THE INVENTION 
We have found that by treating high density information discs, such as 
video discs, with a fluorinating agent, the discs become resistant to, and 
stable under, conditions of high temperature and high relative humidity, 
even after exposure to such conditions for extended periods of time. The 
treatment with the fluorinating agent is usually accomplished by use of a 
bath of an aqueous solution of the fluorinating agent. The fluorinating 
agents employed are "soft" fluorinating reagents, such as fluorosilicic 
acid and fluoroboric acid. 
DETAILED DESCRIPTION OF THE INVENTION 
The high density information discs treated in accordance with the present 
invention are molded from a molding composition comprising a polymer of 
vinyl chloride; finely-divided conductive carbon black particles; a 
stabilizer system which is generally a mixture of tin salts that scavenge 
or take up hydrochloric acid formed as a decomposition product of the 
vinyl chloride polymer during processing; a lubricant system which 
generally is composed of both an internal lubricant, to modify the melt 
viscosity of the molding composition during processing, and an external 
lubricant, to provide release of the molded article, such as a video disc, 
from the mold; and a flow modifier system which is generally composed of 
plasticizers and processing aids to reduce the melt viscosity of the 
molding composition during the processing. 
When large amounts of conductive particles, such as carbon black, are 
present in a molding composition, the melt viscosity greatly increases 
necessitating higher molding temperatures or larger amounts of 
plasticizers and processing aids. Since the present carbon-loaded 
polyvinylchloride molding compositions employed for the video disc contain 
from about 12 up to about 20 percent by weight of carbon black or even 
higher, depending on the type of carbon black used and the dispersion 
obtainable, several processing aids and plasticizers must be added to 
obtain the melt flow properties required to compression mold the 
information disc, which contains information as very small surface relief 
patterns in a very shallow information track. Sufficient lubricants must 
be added to promote ready release of the molded article from the mold 
because any release problems will result in distortion of the record 
during forced release, and even distortion of the stamper from which it is 
molded, which ruins all succeeding discs made from that stamper. 
The polyvinylchloride (PVC) resins suitable for manufacture of the video 
discs include polymers and copolymers of vinyl chloride or mixtures 
thereof. In order to produce desired characteristics in the molded video 
disc, such as dimensional stability, the PVC resin should have a high heat 
distortion temperature, preferably 140.degree. F. (60.degree. C.) or 
higher. Suitable polymers include homopolymers of vinyl chloride, such as 
No. 346 resin of the B. F. Goodrich Co. which has a T.sub.g of 88.degree. 
C., or a copolymer of vinyl chloride/propylene such as AP480 of the Air 
Products and Chemicals Inc. which has a T.sub.g of 76.degree. C. 
Conductive particles suitable for use in the molding composition include 
highly electrically conductive, finely-divided carbon blacks, preferably 
which have a low bulk density to reduce loading requirements. A presently 
preferred product is one of the Armak Co., Ketjenblack EC, which has an 
apparent bulk density of about 140-160 grams per liter and an average 
particle size of about 300 angstroms. Other carbon blacks can also be 
employed, in whole or in part, provided they meet the electrical 
requirements. Denser particles of carbon will generally require higher 
loading, e.g. up to about 40 percent by weight of the molding composition 
in order to obtain an equivalent electrical conductivity. An amount of 
from about 12-20 percent by weight of a carbon black such as Ketjenblack 
EC is preferred. 
Stabilizers, in an amount of from about 1.5-4 percent by weight, are added 
to the chosen PVC--carbon black composition. Suitable stabilizers include 
organotin compounds such as dibutyltin-.beta.-mercaptopropionate, 
commercially available as T-35 from M & T Chemical Co., Inc., dibutyltin 
maleate, commercially available as Mark 275 Argus Chemical Co., and 
stabilizers such as barium-cadmium-lead stearate, commercially available 
as Q-232B of Argus Chemical Co. These stabilizers, as well as others which 
are known and may be used, act primarily to scavenge volatile 
decomposition products of the PVC resin, particularly hydrogen chloride. 
Preferably a combination of more than one stabilizer in a particular 
molding composition is employed. 
Lubricants which are suitable for use with PVC resins are well-known and 
include fatty acids and esters of alcohols and fatty acids, soaps, fatty 
acids amides and the like. Again, a combination of at least two lubricants 
should be used to prevent excessive bleed out of the lubricant during the 
molding process and to provide both internal and external lubrication. 
Suitable lubricants include a mixture of a monofatty acid ester of varying 
molecular weight alcohols and acids, commercially available as Loxiol G-30 
from Henkel International GmbH, Loxiol G-70, a polyfunctional complex 
ester of saturated fatty acids, a room temperature solid esterified montan 
wax commercially available as Wax E of the Hoechst Co., calcium, zinc, or 
lead stearates, stearic amide, oleamide, ethylene bis stearamides, low 
molecular weight paraffin oils such as Olio di Vasilina from Carlo ERBA, a 
division of Chemica Industrialle, Milan, and the like. Sufficient 
lubricants must be added to prevent high shear heating during processing 
and to provide good release from the mold. Generally from about 1 to 3 
percent by weight of the molding composition of a lubricant system will be 
used. 
Additional modifiers including plasticizers and processing aids in amounts 
up to about 10 percent by weight of the resin composition are also added 
to improve the processing and molding characteristics of the resin 
composition. Suitable plasticizers include products such as chlorinated 
paraffin waxes, for example Unichlor 70AX from Neville Chemical Co., 
glyceryl tribenzoate, commercially available as Benzoflex S-404 from 
Velsichol Chemical Corp., epoxicized soybean oils, commercially available 
as Paraflex G-62 from Rohm and Haas Co., Santicizer 711, a primary 
phthalate plasticizer of the Monsanto Company, Kodaflex NP10, a polymeric 
ester plasticizer from Eastman Chemical Products, dicyclohexylphthalate 
and various processing aids such as acrylic modifiers of Rohm and Haas 
Co., commercially available as K-147 and K-175. Other modifiers which can 
be employed are well-known. 
The total amount of liquid modifiers used must be carefully controlled, and 
likewise, these modifiers must be compatible with the vinyl chloride resin 
so that they will not bleed to the surface and create staining. Solid 
modifiers can be compatible or incompatible. Compatible modifiers have a 
much greater effect on the shrinking and heat distortion temperature for 
the resin composition, whereas incompatible modifiers act more like 
fillers and have less effect on these properties. A certain amount of 
compatible modifiers must be present for processability and to overcome 
the stiffening effect of the large amount of conductive carbon particles 
in the resin; however, if too much liquid is added, i.e. more than about 5 
percent by weight of the resin composition, the T.sub.g and heat 
distortion temperature of the molding composition are reduced and the 
warpage and shrinkage characteristics of the molded record will be 
undesirably high. A liquid modifier is defined as a material that is 
liquid at room temperature. However, solid, low melting primary 
plasticizers may also behave as liquids at mixing temperatures and then 
they are also considered to be included as liquid modifiers. 
A presently preferred molding composition for use in making conductive 
video discs comprises from 12-20 percent by weight of the molding 
composition of Ketjenblack EC conductive carbon particles; from 1-3 
percent by weight of dibutlytin-.beta.-mercaptopropionate stabilizer; up 
to 2 percent by weight of a tin maleate stabilizer; from 0.25-1.5 percent 
by weight of Loxiol G-30 lubricant; from 0.15-0.75 percent by weight of 
Loxiol G-70 lubricant; up to 1 percent by weight of calcium stearate 
lubricant; up to 5 percent by weight of acrylic processing aids; a maximum 
of about 4 percent by weight of liquid additives and no more than 10 
percent by weight of solid additives, with the remainder of the 
composition being a polyvinylchloride homopolymer or copolymer of vinyl 
chloride/propylene having a T.sub.g of over 60.degree. C. 
This molding composition can be prepared by mixing all of the solid 
ingredients first in a blender, such as a Henschel mixer until the 
temperature reaches about 120.degree. F. (49.degree. C.), and then adding 
the liquid ingredients which coat the solid particles. Mixing is 
thereafter continued until the temperature reaches about 160.degree. F. 
(71.degree. C.). The composition is then collected and charged to a 
Banbury mixer or other suitable apparatus to melt the ingredients under 
shear. The composition is mixed until it is molten, about 
350.degree.-380.degree. F. (176.degree.-190.degree. C.), and then extruded 
and pelletized for storage. Video disc replicas can be made by compression 
molding in conventional manner, e.g. forming a preform, compression 
molding using a 30-60 second cycle at about 325.degree.-380.degree. F. 
(163.degree.-190.degree. C.) and thereafter removing the flashing. 
A thin lubricant coating is usually added to the video disc. This film 
serves as an added dielectric layer at the surface and also serves to 
reduce stylus wear during playback of the disc. One lubricant type that 
has been employed successfully is a methylalkylsiloxane of the formula: 
##STR1## 
wherein R is an alkyl group of 4-20 carbon atoms and x is an integer. 
These lubricants can be applied by spinning or spraying from solution or 
evaporating onto the disc surface. An improved lubricant is a purified 
fractionated lubricant of the above type wherein R is 10 and x ranges from 
2-3. The purified lubricant can be made by molecular distillation of the 
higher molecular weight material. The lubricant and method of manufacture 
are described by Wang et al. in their copending applications, Ser. Nos. 
065,064 and 065,065, filed Aug. 9, 1979. 
During compression molding of the video disc, many of the above additives, 
or reaction products of these additives including decomposition or 
reaction products of the additives with the PVC or with each other, 
migrate to the surface of the disc where they form a thin film. This thin 
film is a complex mixture of various organic and inorganic materials. It 
is this thin film which is sensitive to moisture and conditions of high 
temperature and high humidity, all of which cause problems in the playback 
of the video disc. 
When a disc as pressed is exposed to the conditions of the atmosphere, 
small droplets of water condense on the surface of the disc. Any salts or 
other water soluble materials that are present on the surface of the disc, 
whether under or adjacent to the water droplets, are dissolved by the 
water droplets. The water droplets may also dissolve water soluble 
materials below the surface of the disc, such as by a wicking or leaching 
effect. As this water evaporates, salts are left on the surface of the 
disc, not now as a uniform thin film, but as lumps or deposits. These 
deposits may cover several information tracks and they may fill up the 
information pattern as well. Thus, the information present in the track 
beneath the deposits is masked or lost during playback by the stylus, 
which rides over the deposits resulting in a loss of signal or dropout of 
the audio, video, and/or color information in that area. Additional signal 
losses occur because the stylus may dislodge some of these deposits during 
playback, and they may collect beneath or in front of the stylus which 
results in further distortion or losses of the signal. 
The distortion, loss of signal, or dropout of the audio, video, and color 
information is measured and reported as carrier distress time. The present 
standard, or pass criteria, for such loss of signal or dropouts for an 
acceptable video disc is a maximum of 3 seconds in 60 minutes of playback 
time, and good quality is considered to be less than 0.3 second in 1 hour 
of playback time. The carrier distress time is measured by adding the 
amount of time in seconds (but discounting intervals of less than 10 
microseconds) when the r.f. output of the player arm is less than 150 
millivolts peak to peak (reference d to a one volt reference level) and 
the time when the r.f. output is above 8.6 megahertz or below 3.1 
megahertz in frequency, indicating a defect. Such defects are noted by the 
viewer as long dropouts, up to a complete loss of picture and sound 
information. 
We have found that by treating these discs with a fluorinating agent, in 
particular, a "soft" fluorinating reagent, the discs become resistant to 
atmospheric conditions, particularly atmospheric conditions of high 
moisture content, and furthermore become stable under conditions of high 
temperature and high relative humidity. Additionally, the so-treated discs 
maintain their original low level of carrier distress, less than 3 seconds 
in 60 minutes of playback time, after repeated exposure to conditions of 
high temperature and high relative humidity for prolonged periods of time. 
The fluorinating agents useful in the treating method of this invention are 
identified as "soft" fluorinating reagents, such as fluorosilicic acid, 
fluoroboric acid, hydrofluoric acid, antimony pentafluoride, and the like. 
These and other soft fluorinating agents, under normal conditions, do not 
cause fragmentation of the functional groups, neither do they saturate 
double bonds, nor do they oxidize metals to their highest valency. 
However, in lieu thereof, these soft fluorinating agents under normal 
conditions convert groups such as RCOOH, RCOH, and ROH to RCF.sub.3, 
RCH.sub.2, and RF, respectively. It has been found that these types of 
polar groups are present on the surfaces of the video discs formed by 
compression molding, as hereinabove described, and originate from the 
carbon black and the thermal decomposition products of the PVC and other 
additives and modifiers employed in molding these video disc replicas. 
Also, it is believed that these types of soft fluorinating agents help to 
convert the hydroscopic chloride salts, such as calcium and barium 
chloride, to moisture insensitive fluoride salts, such as calcium and 
barium fluoride. For best results, we have found that these soft 
fluorinating reagents should be used in an aqueous treatment bath in 
amounts of from about 1 up to about 40 percent by weight based on the 
total weight of the treatment bath, and preferably in amounts of from 2 to 
10 weight percent of the soft fluorinating agent. 
The discs can be treated by immersing in the treating solution, or by 
spraying and the like. The solution can be agitated to improve the 
treatment of the disc, as by mechanical stirring, or ultrasonic agitation 
and the like. A turbulent type of action of the treating solution can also 
be directed at the surface of the disc, if desired, to aid in the treating 
of the disc. Multiple immersions of the disc in the treating solution can 
be employed and a final rinse with purified water can also be beneficially 
used. After treating with the solution, the discs may be air or solvent 
dried. 
The following specific examples are included in order to illustrate the 
invention and the improvement thereof with greater particularity. However, 
it is to be understood that these examples are not intended to limit the 
invention in any way.

EXAMPLE I 
In this example a series of video discs were compression molded from a 
molding composition containing 75.15 parts of the PVC resin 346 referred 
to above, 14.8 parts of Ketjenblack EC carbon particles, 1.5 parts of T35 
and 1.0 part of Mark 275 as stabilizers, 0.75 part of G-30, 0.25 part of 
G-70, 0.5 part of calcium stearate, and 0.3 part of Olio di Vasilina as 
lubricants, 0.75 part of K-175 processing aid, 2.0 parts of K-147 
processing aid, and 3.0 parts of Santicizer 711 modifier. The discs were 
compression molded from this composition at a temperature of about 
360.degree. F. (182.2.degree. C.). 
The discs from this press run were divided into three lots of six discs 
each for purposes of further processing and comparative evaluation. 
Next, a first solution was prepared by mixing 13.35 liters of a 60 weight 
percent solution of fluorosilicic acid in 66.65 liters of water to form a 
solution containing 10 weight percent fluorosilicic acid. This solution 
was then charged to a first treatment tank. 
A second solution was then prepared by mixing 3.2 liters of a 50 weight 
percent solution of fluoroboric acid in 76.8 liters of water to form a 
solution containing 2 percent by weight of fluoroboric acid. This solution 
was then charged to a second treatment tank. 
Then the first lot of six discs were mounted in the first tank containing 
the fluorosilicic acid solution and revolved therein for approximately 3 
minutes. These discs were then rinsed with deionized water for 5 minutes 
and thereafter dried under nitrogen. Also, the second lot of six discs 
were mounted in the second tank containing the fluoroboric acid solution 
and revolved therein for a period of approximately 3 minutes. Thereafter 
these discs were rinsed with deionized water for a period of approximately 
5 minutes and then dried under nitrogen. 
The third lot of six discs were used as a control and were treated in 
accordance with the heretofore known and commercially used video disc 
cleaning process. This commercially used cleaning process includes 
cleaning the discs with a 5 percent aqueous solution of Shipley 1160B 
conditioner available from the Shipley Co., which is followed by a rinsing 
with deionized water and drying in a freon atmosphere. The Shipley 1160B 
conditioner is an aqueous solution of organic alcohols which is 
commercially available from the Shipley Co. 
Thereafter, a lubricant layer was applied to all video discs of each lot as 
a 1 percent solution in heptane of the lubricant of the formula: 
##STR2## 
made in accordance with the method described by Wang et al. in the 
copending applications referred to hereinabove. 
Each of the three lots of discs, each containing six discs, was subjected 
to environmental stress conditions of high temperature and high humidity. 
In this testing the discs were taken from ambient room temperature 
conditions and placed into a chamber maintained at 100.degree. F. 
(37.7.degree. C.) and 90 percent relative humidity and held under these 
conditions for a period of 196 hours. Thereafter, the discs were 
transferred to and held for a period of 2 hours at ambient room 
temperature conditions. 
Each of the discs was then played and the carrier distress measured and 
determined for each disc. It was found that after being subjected to the 
196 hours of high temperature, high humidity conditions of stress, the 
discs of lots 1 and 2, treated respectively with the fluorosilicic acid 
solution and the fluoroboric acid solution of this invention, had an 
average carrier distress of 2 seconds in 60 minutes of playback time, 
while the discs of the third lot, treated in accordance with the 
heretofore known and commercially used cleaning process, had an average 
carrier distress of 33 seconds in 60 minutes of playback time. 
Additionally, it was found that the carrier distress of all discs of lots 
1 and 2 (treated in accordance with this invention) did not increase after 
being subjected to 196 hours of the high temperature and high humidity 
(100.degree. F.-90 percent RH) conditions. 
EXAMPLE II 
In this example, three lots of video discs, each containing six discs, were 
prepared and treated as in Example I. 
After lubrication, but prior to exposure to high temperature, high humidity 
environmental conditions of stress, the carrier distress time was measured 
and determined for the initial playback of each disc. Then the discs were 
exposed as before to environmental stress conditions of high temperature, 
high humidity (100.degree. F. (37.7.degree. C.) and 90 percent RH). The 
discs were played and the carrier distress time was measured and 
determined for each disc after an interval of 48 hours and again after a 
time period of 192 hours of exposure to the high temperature, high 
humidity conditions. The results obtained in these tests are summarized 
hereinbelow in Table I. 
TABLE I 
__________________________________________________________________________ 
Carrier Distress - in Sec. per 30 Min. Playback Time 
After 48 hrs. 
After 192 hrs. 
Initial Play 
Stress Stress 
Treatment Average 
Range 
Average 
Range 
Average 
Range 
__________________________________________________________________________ 
LOT 1 
H.sub.2 SiF.sub.6 - 10 percent solution 
3.1 0.2-5 
0.3 0.2-0.7 
0.8 0.1-1.9 
LOT 2 
HBF.sub.4 - 2 percent solution 
2.9 0.1-7.5 
0.4 0.1-2.6 
1.0 0.3-4.0 
LOT 3 (CONTROL) 
Shipley 1160B 0.1 0-0.1 
1.0 0.1-2.7 
17.6 0.4-94 
__________________________________________________________________________ 
EXAMPLE III 
In this example, a series of video discs were compression molded as in 
Example I from the molding composition set forth in that example using two 
different stampers, which are identified as "Stamper A" and "Stamper B" in 
the following Table II. 
After compression molding, the discs were separated into three lots for 
further processing, testing, and comparison. Each of the lots, identified 
as "Lot 1", "Lot 2", and "Lot 3" in Table II hereinbelow, contained 48 
discs, with 24 discs in each lot being molded from "Stamper A" and 24 
discs of each lot being molded from "Stamper B". 
The first lot of discs, identified as Lot 1, was given no further 
processing other than to be lubricated as set forth in Example I. The 
second lot, Lot 2, was cleaned in accordance with the aqueous cleaning 
solution disclosed by Datta in the copending application referred to 
hereinabove. This cleaning solution included 500 parts of 30 percent 
hydrogen peroxide, 500 parts of 36 percent ammonium hydroxide, and 7 parts 
by volume of a fluorosurfactant, commercially available as Fluorad FC-93, 
in 10,000 parts of water. Fluorad FC-93 fluorosurfactant is an ionic, 
ammonium perfluoroalkylsulfonate commercially available from 3M Company. 
The discs of Lot 3 were treated by the 10 percent fluorosilicic acid 
treatment solution of Example I to which a small amount of Fluorad FC-93 
surfactant had been added in order to provide good wetting of the 
irregularly shaped disc surface. 
All discs of all three lots were then lubricated as in Example I and 
thereafter exposed to the high temperature, high relative humidity 
environmental stress conditions as in Example I. The high temperature, 
high relative humidity environmental stress conditions were maintained at 
100.degree. F. (37.7.degree. C.) and 95 percent relative humidity in this 
example. All discs were maintained under these conditions of high 
temperature, high humidity for a first period of 48 hours which was then 
followed by a second 48-hour period. 
The discs were played and carrier distress time was measured and determined 
for each disc of all lots prior to the exposure to the environmental 
condition stress test and again after each 48-hour period of stress 
testing. The results obtained by this testing are summarized below in 
Table II. 
TABLE II 
__________________________________________________________________________ 
Carrier Distress - in Sec. per 60 Min. Playback Time 
After 48 hrs. 
After 96 hrs. 
Initial Play 
Stress Stress 
% Pass- % Pass- % Pass- 
Treatment Mean 
3 sec. 
Mean 
3 sec. 
Mean 
3 sec. 
__________________________________________________________________________ 
LOT 1 (CONTROL) 
(untreated) 
Stamper A 2.5 60% 45 0% 55 0% 
Stamper B 3.8 45% 52 0% 60 0% 
LOT 2 
(peroxide-ammonium- 
surfactant treated) 
Stamper A 0.4 80% 5.3 25% 7.7 15% 
Stamper B 0.2 90% 6.7 20% 9.3 10% 
LOT 3 
(H.sub.2 SiF.sub.6 - surfactant 
treated) 
Stamper A 0 100% 1.2 65% 3.1 45% 
Stamper B 0.1 90% 0.9 80% 2.5 60% 
__________________________________________________________________________ 
As can be seen by a careful analysis of the above Examples and the data 
contained therein, the improved disc treatment of this invention, with 
aqueous solutions of "soft" fluorinating reagents, provides a substantial 
improvement in the carrier distress of the treated discs after exposure to 
environmental conditions of high temperature and high relative humidity, 
when compared to prior known, disclosed, and commercially used treating 
processes. The fluorinating treatment of high density information discs, 
such as video discs, by the method of this invention using "soft" 
fluorinating reagents has been found to be an effective means of lowering 
the carrier distress and reducing ambient aging of the discs due to 
migration of hydroscopic materials, and their sensitivity to conditions of 
high humidity and high temperature.