Classifications

• • G—PHYSICS
  • G11—INFORMATION STORAGE
  • G11B—INFORMATION STORAGE BASED ON RELATIVE MOVEMENT BETWEEN RECORD CARRIER AND TRANSDUCER
  • G11B3/00—Recording by mechanical cutting, deforming or pressing, e.g. of grooves or pits; Reproducing by mechanical sensing; Record carriers therefor
  • G11B3/68—Record carriers
  • G11B3/70—Record carriers characterised by the selection of material or structure; Processes or apparatus specially adapted for manufacturing record carriers
  • G11B3/705—Record carriers characterised by the selection of material or structure; Processes or apparatus specially adapted for manufacturing record carriers characterised by the selection of the material only
• • G—PHYSICS
  • G11—INFORMATION STORAGE
  • G11B—INFORMATION STORAGE BASED ON RELATIVE MOVEMENT BETWEEN RECORD CARRIER AND TRANSDUCER
  • G11B23/00—Record carriers not specific to the method of recording or reproducing; Accessories, e.g. containers, specially adapted for co-operation with the recording or reproducing apparatus ; Intermediate mediums; Apparatus or processes specially adapted for their manufacture
  • G11B23/0057—Intermediate mediums, i.e. mediums provided with an information structure not specific to the method of reproducing or duplication such as matrixes for mechanical pressing of an information structure ; record carriers having a relief information structure provided with or included in layers not specific for a single reproducing method; apparatus or processes specially adapted for their manufacture

Definitions

• R 1 is a non-hydrolyzable divalent hydrocarbon group (aliphatic, aromatic or aliphatic and aromatic containing) of less than 20 carbon atoms or a divalent group having less than 20 carbon atoms composed of C, H, S, N, and O atoms as the only atoms which may appear in the backbone of the divalent group, the O atoms appearing as ether linkages if present, and with no two adjacent heteroatoms in the divalent group.
• This description is the definition of non-hydrolyzable divalent group for R 1 ;
• R 2 is an aliphatic group of less than 10 carbon atoms or an acyl group of less than 10 carbon atoms; and m is 0 or 1.
• the group R 1 is preferably alkylene of from 1 to 8 carbon atoms and most preferably is represented by the formula:
• the group R 2 is preferably alkyl of 1 to 6 carbon atoms, more preferably alkyl of 1 to 3 carbon atoms, and most preferably methyl.
• compositions used in making the information storage layer for the discs of the present invention include from 30-100% by weight of the epoxy-terminated silane. That is, the information carrying layer is the crosslinked product of the epoxy-terminated silane in combination with from 0-70% by weight of a copolymerizable material.
• copolymerizable materials include styrene, methyl styrene, vinyl amides, vinyl ethers, epoxy resins, polyols, silanes and other materials known to be copolymerizable with either epoxy resins or silanes.
• the most preferred comonomers are epoxy compounds. These may generally be described by th formula:
• R 3 is an aliphatic or cycloaliphatic group
• r is the valence of R 3 and is an integer of from
• a and b are H, or when fused together, represent the atoms necessary to form a 5- or 6-membered cycloaliphatic ring.
• said epoxy resin upon homopolymerization, forms a polymer having a glass transition temperature below +25°C and has a molecular weight of at least 100 per epoxy group.
• Preferred compounds are the diglycidyl ether of bisphenol A,
• polyacryloyl containing heterocyclics are defined according to the present invention as materials described by the formulae: 1) A 1 -Z-A 2 wherein A 1 and A 2 independently are alkoxyalkyl groups having terminal ethylenic unsaturation and having the formula
• R 5 is an aliphatic group having from 1 to 15 carbon atoms, and no more than two non-adjacent catenary oxygen or carboxy groups, a valence of m + 1, m is an integer of from 1 to 5, R 2 is selected from hydrogen and groups of the formula
• R 6 is selected from alkyl and alkenyl groups
• R 3 is an alkylene group of from 1 to 6 carbon atoms with up to one catenary oxygen atom
• Z is a heterocyclic group of the formula wherein X is a divalent group which is required to complete a 5- or 6-membered heterocyclic ring, or
• R 12 and R 13 independently represent hydrogen or methyl
• R 14 represents hydrogen, an alkyl group, or a phenyl group
• A represents a group of the formula
• R 8 , R 9 , R 10 and R 11 are independently hydrogen, alkyl group of 1 to 4 carbon atoms, cycloalkyl group of 3 to 6 carbon atoms, and aryl group (e.g., phenyl group) of 6 to 12 carbon atoms, and A 3 is an alkoxyalkyl group as defined for A 1 and A 2 , and b) from formula 2): wherein m is from 1 to 4, and X 1 is selected from
• R 15 , R 16 , R 17 and R 18 independently represent hydrogen, an alkyl group, an alkylene group, a cycloalkyl group, or a phenyl group, and
• R 8 and R 9 be hydrogen or alkyl of 1 to 4 carbon atoms, that m be 2 to 5, that R be [ (CH 2 ) b ] m R 5 (CH2) C ' that R 5 be alkylene of 1 to 15 carbon atoms, and/or that R 4 be hydrogen. It is more preferred with regard to formula 2) that X 1 be selected from
• the information bearing layer of the disc blanks or discs of the present invention must be formed from a polymeric resin derived from a composition comprising at least 15% by weight of the polyacryloyl heterocyclics.
• the heterocyclics may of course constitute 100% by weight of reactive or polymeric components in the resin.
• the compositions used in the process of the present invention may be diluted with up to 85% by weight of any ethylenically unsaturated monomer.
• Preferably the majority of comonomers are at least diethylenically unsaturated monomers.
• Generic classes include the acrylates, methacrylates, acrylic anhydrides, ethylenically unsaturated anhydrides, olefinic compounds, acrylamides, ethylenically unsaturated amides and urethanes, vinyl esters, vinyl ethers, vinyl halides, vinyl epoxy resins, vinyl silanes and siloxanes, vinyl heterocyclics, and prepolymers and polymers of these materials.
• compositions should also contain polymerization or free radical initiators in order to provide more photosensitivity to the system to speed up the cure.
• Polymerization initiators suitable for use in the compositions of the invention are compounds which liberate or generate a free-radical on addition of energy. Such initiators include peroxy, azo, and redox systems each of which are well known and are described frequently in polymerization art, e.g. Chapter II of Photochemistry, by Calvert and Pitts, John Wiley and Sons (1966).
• free-radical catalysts include the conventional heat activated catalysts such as organic peroxides and organic hydroperoxides; examples are benzoyl peroxide, tertiarybutyl perbenzoate, cumene hydroperoxide, azobis( isobutyronitrile) and the like.
• the preferred initiators are photopolymerization initiators which facilitate polymerization when the composition is irradiated.
• the initiator is used in amounts ranging from about 0.01 to 5% by weight of the total polymerizable composition. When the quantity is less than 0.01% by weight, the polymerization rate becomes extremely low. If the initiator is used in excess of 5% by weight, no correspondingly improved effect can be expected.
• the structure of the information carrying discs of the present invention comprises a substrate having the information impressed or blank groove impressed epoxyterminated silane coating layer on at least one side thereof.
• the substrate may be substantially any solid material, including but not limited to polymeric materials such as polycarbonates, polyesters, polyacrylates, polyurethanes, polyolefins, polyvinyl resins, polyamides, and polysiloxanes; ceramic or glass materials; fibrous materials; metals; etc.
• the surface of the substrate to be coated should itself be smooth. It would not be desirable to have surface irregularities having dimensions in excess of 2 ⁇ m.
• the backing may be transparent or opaque depending upon the readout system used. If the backing is opaque, a master transparent to the curing radiation must be used.
• Primer layers may be used between the substrate and the information carrying layer, but this is not essential depending upon the ability of the coating to adhere to the base.
• polyesters for example, polyvinylidene chloride is a useful primer.
• the substrate may be of any thickness, but is usually from 50 to
• the information carrying layer is critical in its dimensions and must be between 1.0 and 25 ⁇ m in its maximum thickness for a video disc and up to 100 ⁇ m for an audio disc.
• the term maximum thickness is used, because the layer, having depressions, protuberances, or grooves thereon, varies in thickness. This limit therefore applies to the maximum thickness of the layer above the substrate. Preferably it is between 2.0 and 20 ⁇ m in maximum thickness and most preferably between 3.0 and 10 ⁇ m for a video disc.
• the preferred dimensions are between 15 and 75 ⁇ m for an audio disc.
• the information is encoded on the information carrying layer as depressions, protuberances, and/or grooves with or without modulations in either a circular, arc-like (e.g., semicircular, hyperbolic, etc., or spiral pattern on the layer.
• the depth or height of the information carrying deformity from the plane of the surface or the mean height of the surface is normally between 0.03 to 2 ⁇ m.
• this dimension is usually between 0.03 and 1.5 ⁇ m, preferably between 0.05 and 0.8 ⁇ m, and more preferably between 0.07 and 0.5 ⁇ m.
• stylus readout systems this dimension is usually between 0.05 and 2 ⁇ m, preferably between 0.08 and 1.5 ⁇ m, and more preferably between 0.10 and 1.0 ⁇ m.
• this dimension is preferably between 25 and 75 ⁇ m.
• the width (peak to peak) between grooves in audio systems is about 60-80 ⁇ m.
• the light read systems may have a metallized coating over the information carrying surface and another polymer layer, preferably of an abrasion resistant material, over the metal layer, if a reflective rather than transmissive readout system is being used.
• These coatings can be laid by a variety of manners including vapor deposition or reduction of metal salt solutions.
• two reflectively metallized discs may be adhesively secured together so that the two information bearing surfaces are sandwiched in the middle of the composite and information is then read reflectively through a transparent substrate.
• Capacitively read discs may have a metallized coating applied to the replicated information bearing surface to provide electrical conductivity. The metallized coating may then be provided with an electrically insulative overlayer.
• Replicas to be read with a stylus may also use a lubricant or lubricating layer on the information bearing surface to minimize stylus wear.
• the information is encoded into the information carrying layer in a spiral pattern rather than a circular pattern so that the reading element can follow a single path rather than having to shift from one concentric circle to another.
• the composition of the information carrying layer may include various materials which may improve or not adversely affect the properties of the layer.
• the use of alkoxy substituted metals in epoxyterminated silanes such as disclosed in column 5, lines 36-59 of U.S. Patent 4,049,861 will improve the conductivity of the layer and reduce static charge buildup.
• Polymeric additives such as those disclosed for epoxyterminated silanes in U.S. Patents 3,955,035 and 4,082,846 may be useful.
• Flow control aids and surfactants as are well known in the art, could be added to compositions of the present invention. Dyes could be added to the compositions which would be transmissive of the radiation used to read the encoded information.
• 4,130,690 shows a class of Lewis acid catalysts of high efficiency for curing epoxy-terminated silanes.
• the more preferred catalysts are the highly fluorinated aliphatic sulfonylic catalysts, the high efficiency Lewis acid catalysts (PF 6 , SbF 6 and HSbF 6 ) and the complex polyaromatic sulfonium and iodonium salts (i.e., those having BF 4 - , PF 6 - , SbF 6 - , SbF5-OH and ArF 6 " as anions).
• PF 6 , SbF 6 and HSbF 6 the complex polyaromatic sulfonium and iodonium salts
• One important aspect of the present invention is that the low applied pressures and low temperatures associated with the use of liquid compositions allows for the use of non-metallic stampers and masters.
• a highly hydrolyzed precondensate of ⁇ -glycidoxypropyltrimethoxy silane (about 80-90% of methoxy groups removed) (70 gm) was mixed with 30 gm of 1,4-diglycidoxylbutane and 2 gm of triarylsulfonium hexafluoro-antimonate photocatalyst (described in assignee's U.S. Patent No. 4,173,476) by shaking for 3 hours. Bubbles were then removed from the mixture by placing it in an evacuated chamber for 15 minutes. The resulting photopolymerizable material was used to make a video disc replica according to the following roll coating process.
• a nickel video disc stamper was utilized. Approximately 2.0 cm 3 of the material prepared as described above was spread by a cylindrical coating roller between a video disc stamper and a primed 0.18 mm polyester film. The sheet of 0.18 mm thick polyester film was positioned between the stamper and the roller to serve as a base element. This rolling process spread out a bubble free coating of resin composition over the surface of the stamper and simultaneously covered it with the polyester sheet. The stamper covered in this manner was then passed at 3 cm/sec under a 200 watt/inch high intensity medium pressure Hg vapor lamp. The UV exposure cured and hardened the resin composition. After this exposure, the laminated structure containing the replicated information was easily peeled from the nickel stamper. The sheet was then cut to produce a circular center hole and a circular outside edge, both concentric with the replicated information tracks.
• the resulting video disc replica had an information bearing layer which was approximately 10 ⁇ 5 ⁇ m thick which did not curl when layed on a flat surface. It retained this flatness after more than one year under ambient conditions and produced a good television picture when played on a commercial video disc player. A haze value of less than 20% was obtained according to A.S.T.M. D-1044-76.
• Example 2 A video disc replica was made as in Example 1. However, the resin composition used was made by mixing 90 gm of the precondensate of Example 1 with 10 gm of the diglycidyl ether of 1,4-butanediol and 2 gm of the photocatalyst of Example 1.
• the video disc replica made by this process has an information bearing layer which was 8 ⁇ 5 ⁇ m thick.
• the replica was initially flat, but in three months, developed a curl which then made it unsuitable for playing on a video disc player. It has been found that it is desirable to have increasingly thinner coating layers and, to some degree, thicker substrates, as higher percentages of epoxy-terminated silane are used.
• the disc of this example was highly abrasion resistant and initially produced an excellent video image upon being played.
• Example 3 A video disc replica was made as in Example 1 with the following changes.
• the resin composition was made by mixing 50 gm of the precondensate, 50 gm of the diepoxide of Example 1 and 2 gm of the photocatalyst.
• the resulting disc replica had a cured information bearing layer which was 7 ⁇ 3 ⁇ m thick. This replica did not curl when laid on a flat surface. It retained its flatness even after a one month period of time. The replica produced a good television picture when played on a video disc player.
• Example 4 A video disc replica was again made as in Example 1, however, the resin composition was a mixture of 100 gm of the precondensate of Example 1 and 2 gm of the photocatalyst. The resulting video disc had an information bearing layer which is 14 ⁇ 4 ⁇ m thick. It was initially flat, but upon standing for three months, it developed a curl which then made it unsuitable for playing on a video disc player.
• a resin composition was made by mixing 70 gm of a 50 to 60% hydrolyzed precondensate of ⁇ -glycidoxypropyltrimethoxy silane with 30 gm of the diepoxide of Example 1 and 2 gm of the photocatalyst of Example 1.
• the resulting material was used to make a video disc according to the procedure of Example 1.
• the video disc replica made in this way had a cured information bearing layer 7 ⁇ 3 ⁇ m thick. This disc lay flat when placed on a level surface. It maintained its flatness after aging under normal room conditions for three months. It provided a good television picture when played on a video disc player.
• Example 6 A video disc replica was made as in Example 5.
• the resin composition was made by mixing 50 gm of the precondensate of Example 5, 50 gm of the same diepoxide of Example 1 and 2 gm of the photocatalyst of.
• Example 1 The resulting disc replica had an information bearing layer thickness of 7.5 ⁇ 2.5 ⁇ m. It lay flat when placed on a level surface and maintained this flatness after aging at normal room conditions for three months.
• Example 7 A video disc replica was made as in Example 5. However, the resin composition was made by mixing 30 gm of the precondensate of Example 5, 70 gm of the diepoxide of Example 1, and 2 gm of the photocatalyst of Example 1. The resulting replica had an information bearing layer with a thickness of 3 ⁇ 2 ⁇ m. Both before and after aging three months under normal room conditions, this disc lay flat when placed on a level surface. It produced a good television picture when used with a video disc player.
• Example 8 A video disc replica was made according to the procedure of Example 1.
• the resin composition was made by mixing 100 gm of the precondensate of Example 5 with 2 gm of the photocatalyst of Example 1.
• the resulting replica had an information bearing layer which was 6.5 1 1.5 ⁇ m thick. When first made, this disc lay flat when placed on a level surface. However, after aging under normal room conditions for three months, it curled up when placed on such a surface and was then not suitable for playing on a video disc player.
• Example 9 A video disc replica was made according to the procedure of Example 1.
• the resin composition used was a mixture of 90 gm of the precondensate of Example 5, 10 gm of the diglycidyl ether of 1,4-butanediol and 2 gm of the photocatalyst of Example 1.
• the resulting disc had an information bearing layer with a thickness of 6.5 1 1.5 ⁇ m.
• the disc lay flat when placed on a level surface. However, after aging for three months under normal room conditions, the disc curled up when placed on such a surface and was then not suitable for use on a video disc player.
• Examples 10-14 Video disc replicas were made according to the procedure of Example 1.
• the resin composition was a mixture of ⁇ -glycidoxypropyltrimethoxysilane, the diglycidyl ether of 1,4-butanediol and the catalyst of Example 1.
• the amount of each component used for the corresponding example is shown below.
• Examples 15-22 A series of discs were made according to the procedure of Example 1. The hydrolyzable silane or precondensate thereof and the amount of diglycidyl ether of 1,4-butanediol in the resin composition are shown below. These discs were then cured by placing them for 7 minutes under a bank of low intensity "black lights.” All these discs were flat and produced a good television picture when first produced. Examples 15-18 were then aged for 71-1/2 hours at 55°C, 16% R.H. All discs retained their flatness in this aging. Examples 19-22 were aged 71-1/2 hours at 50°C, 85% R.H. None of the discs curled appreciably when subjected to this environment. However, because of the low levels of epoxy-terminated silane (ETS), Examples 15-22 were not abrasion resistant.
• ETS epoxy-terminated silane
• Example 31 A series of discs was made according to the procedure of Example 1. The hydrolyzable silane or precondensate thereof and the components of resin composition are shown below. All of these discs were adequately flat immediately after preparation. However, after aging 74 hours at 55°C, 17% R.H. , the disc of Example 28 had developed an excessive curl. When these discs were further aged for 88 hours at 50°C and 85% R.H., the discs of Examples 23, 24 and 27 also developed excessive curl. These results and the results of Examples 15-22 tend to indicate that adding a flexibilizer helps to maintain disc flatness. It is also important to note that the discs with thick information bearing layers curled more than those with thin coatings. Example 31
• a resin composition was made by mixing 50 gm of the precondensate of Example 1 with 50 gm of the diepoxide of Example 1, 2 gm diphenyliodonium hexafluorophosphate and 0.4 gm 2-ethyl-9,10-dimethoxyanthracene.
• the resulting material was used to make a video disc according to the procedure of Example 1 except that the resin was cured under a bank of low intensity "black lights" for 7 minutes.
• the video disc replica made in this way had a cured information bearing layer 7.5 ⁇ 2.5 ⁇ m thick. This disc lay flat when placed on a level surface. It provided a good television picture when played on a video disc player.
• a haze value of less than 25% was obtained according to A.S.T.M. D-1044-76.
• Example 32 A resin composition was made by mixing 50 gm of the precondensate of Example 5 with 50 gm of the diepoxide of Example 1, 2 gm diphenyliodonium hexafluorophosphate and 0.4 gm 2-ethyl-9,10-dimethoxyanthracene. The resulting material was used to make a video disc according to the procedure of Example 1 except that the resin was cured under a bank of low intensity "black lights" for 7 minutes. The video disc replica made in this way had a cured information bearing layer 7.5 ⁇ 2.5 ⁇ m thick. This disc lay flat when placed on a level surface. It provide a good television picture when played on a video disc player.
• Example 33 A sample of commercially available PVC film 14 inches square was prepared for use as a video disc substrate in the following two steps.
• the sheet was placed between two flat, smooth chrome-steel plates.
• the plates were in turn sandwiched between four layers of cardboard and the resultant stack pressed for 10 minutes in a hydraulic press.
• the press was operated with a force of 114 metric tons, and the press platens were held at a temperature of 160°C.
• the pressing operation reduced the surface roughness present on the manufactured film and provided suitable flatness.
• Example 34 A sheet of cast acrylic material (polymethylmethacrylate) 1 mm thick was sputter-etched according to the procedure of Example 33 in order to promote adhesion of the photopolymer. The resin composition of Example 1 was used.
• Example 2 The roll-coating technique of Example 1 was used, but the semi-flexible base element was allowed to bend slightly when it was simply lowered slowly onto the stamper as the roller moved along.
• the resin composition was cured with a bank of low intensity UV lamps, and the replica stripped from the stamper.
• An aluminum coating 30 nm thick was vapor coated on the surface of the information bearing layer.
• a circular hole was cut in the center of the disc, and a circular outer edge was cut.
• the resulting disc was then placed on a commercial video disc player.
• the laser beam was incident through the uncoated acrylic surface. A good television picture was obtained.
• Table 4 thus helps to illustrate that, for the base elements chosen and thicknesses of information bearing layers produced, in order to avoid curl with hydrolyzed monomer and low signal level with non hydrolyzed monomer, at least about 30% by weight of comonomer flexibilizing material is preferred. It is also useful to observe where the information bearing layer begins to lose its abrasion resistance. Thus, for substantial abrasion resistance, it appears desirable to use less than about 70 percent by weight of comonomer flexibilizing agent.
• the resulting photoresist master was used in place of a nickel stamper to make a video disc replica according to the procedures of Example 1. This replica was playable. When vapor coated with 10mm of chrome and used in place of a nickel stamper, repeated playable replications were made.
• Example 42 A sheet of cast acrylic material (polymethylmethacrylate) 1000 ⁇ m thick was sputter etched according to the following procedure to promote adhesion of the polymer.
• the acrylic substrate was placed in a Vecco Model 776 radio frequency diode sputtering apparatus operating at a frequency of 13.56 MHz.
• the substrate was then subjected to a radio frequency sputter etch as described in assignee's copending application Serial No. 80,530, filed 10 October 1979.
• Example 1 The resin composition of Example 1 and the roll coating technique of Example 1 was used to prepare a video disc replica with the above described substrate.
• the semi-flexible substrate was allowed to bend slightly when it was lowered slowly onto the stamper as the roller moved along.
• the resin composition was cured with a bank of low intensity UV lamps, and the replica removed from the stamper.
• An aluminum coating 30 nm thick was vapor coated onto the surface of the information bearing layer.
• a circular hole was cut in the center of the disc, and a circular outer edge was cut.
• the resulting disc was then played on a video disc player; a good television picture was obtained.
• the laser beam of the player was incident through the uncoated acrylic surface and reflected by the aluminum coating on the information bearing surface.
• Example 43 An audio record replica was prepared using commercially available 1 mm polyvinylchloride as the base element.
• the resin composition of Example 1 was used within the roll-coating technique of Example 1.
• the semi-flexible base element was allowed to bend slightly as it was lowered slowly on to the audio record stamper as roller moved along.
• the resin composition was cured to 75 ⁇ m maximum thickness by several passes at 3 cm/sec. under a 200 watt/inch high intensity, medium pressure Hg vapor lamp.
• the replica was then stripped from the stamper. A circular hole was cut in the center of the record and a circular outer edge was cut. The resulting replica was successfully played on a conventional stereo audio system.

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• Casting Or Compression Moulding Of Plastics Or The Like (AREA)
• Optical Record Carriers And Manufacture Thereof (AREA)
• Pharmaceuticals Containing Other Organic And Inorganic Compounds (AREA)
• Photoreceptors In Electrophotography (AREA)
• Epoxy Resins (AREA)
• Silicon Polymers (AREA)

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• 1980
  • 1980-12-23 JP JP81500390A patent/JPS57500070A/ja active Pending
  • 1980-12-23 DE DE8181900195T patent/DE3070822D1/de not_active Expired
  • 1980-12-23 WO PCT/US1980/001715 patent/WO1981002137A1/en not_active Ceased
  • 1980-12-23 EP EP81900195A patent/EP0044840B1/en not_active Expired
  • 1980-12-23 AU AU66496/81A patent/AU544137B2/en not_active Ceased

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