FI119860B - New uses for paper and board - Google Patents

Description

NEW USES OF PAPER AND PAPERBOARD

BACKGROUND OF THE INVENTION Field of the Invention

The present invention relates to optical disks. In particular, the invention relates to disposable and recyclable optical discs, such as digital versatile discs, comprising a substrate having two opposed surfaces and provided with a planar polymer layer on at least 10 disks on one face. The invention also relates to a method of making such a sheet.

The invention further provides a new use for a sheet of paper and board.

The present invention can be used in industries that benefit from the limited time storage of digital data, such as in the film, and computer or console rental business, or in the music industry as demo discs media. It can also be used for unlimited data storage solutions.

20 Description of the Related Art

Conventional single-sided single-layer DVDs generally comprise a first polycarbonate sheet of substantially 0.6 mm in diameter, 120 mm in diameter, a thin reflective metal layer and a second protective polycarbonate sheet. A high resolution pattern comprising wells smaller than micrometers and flat areas, i.e. digital data, is produced on the first disk so that the data is protected between the plates.

Various attempts have been made to develop optical discs with a limited lifespan. Prior art solutions generally focus on polycarbonate-based discs containing means for damaging the disc, for example, chemicals to degrade the optical properties of the disc within a certain time of opening the disc housing, or when the disc is exposed to a laser for reading on a disc player. These techniques are briefly described below.

2 U.S. Patent No. 6,537,635 relates to discardable optical media containing pseudo-reflective material which, when exposed to air for a period of time, changes to render the disc unreadable. The use of air-sensitive pseudo-permeable layers of material on a reflective layer is disclosed in U.S. Patent No. 6,511,728. Both of these techniques 5 are based on preventing the passage of light from the laser source into the reflective layer and back by damaging the reactive layer, which is either reflective or permeable, by exposure to air.

A disadvantage of the above-mentioned technique is that the plates must be protected from air contact until they are first used, i.e. during manufacture, packaging and transport, which significantly increases the cost of the process. In addition, polycarbonate, which is typically used as a board material for boards, is not an environmentally friendly material, which makes it difficult to dispose of boards.

U.S. Patent No. 6,011,772 reproduces the use of a removable barrier layer, which, upon removal of the layer, is rendered operative, either immediately or after exposure to optical radiation, and renders the disk slowly unreadable. A slightly different limited life optical disc is disclosed in U.S. Patent No. 6,468,619. The disc substrates disclosed therein have a reservoir containing a chemical substance that interacts with the data layer of the disc to render it illegible upon release of the chemical agent. The release of the chemical can take place through mechanical or electrical interactions that occur when a suitable disc case is opened.

U.S. Patent No. 6,531,262 discloses a method for making optical media read-only in a controlled manner. In the method, an uneven reading surface and a smoothing coating layer are provided on the media and a photosensitive chemical is added to the plate. When the disc is exposed to a read laser, the coating layer shrinks and an uneven, non-read layer is exposed.

In the two above-mentioned methods, the boards must be packaged in a special manner, for example to protect them from light or mechanical movement. The methods also require the use of non-recyclable materials such as polycarbonates and chemicals.

WO 04068484 discloses recordable optical discs having a resin-impregnated paper as a substrate as a substrate. The manufacturing method 3 disclosed in the publication comprises preparing a separate embroidery layer, which includes forming a groove in the embossing layer and embedding the embroidery layer in the substrate. Thus, data must be migrated to the rendering loop before the mount step, or the disks are intended for home writing.

WO 03002330 discloses a method for making holograms on a paper, plastic film or other product by embossing a holographic image on a thermoplastic coating on the product. The coating comprises, inter alia, plastic pigment particles and a thermoplastic polymer preparation. However, the method is limited to the production of conspicuous holograms, for example in security applications, and not to the storage of high-resolution digital data.

Summary of the Invention

The object of the invention is to eliminate at least some of the problems of the prior art and to provide a new optical disk which can be made from environmentally friendly and fully recyclable materials which can be easily disposed of after use.

Another object of the invention is to provide a novel process for the production of recyclable or disposable optical discs.

20

A third object of the invention is to provide a new use for coated paper and board sheets, webs, and other similar planar paper and board products.

These and other objects, as well as the advantages over the known disposable plates and their methods of manufacture, which will be apparent from the following description, will be achieved by the description and claims of the present invention.

The invention is based on the idea of using a coated paper or board sheet as a substrate for a recyclable or disposable optical disc. We have found that ordinary sheets of paper and board made up of cellulose fibers, fillers, and possibly adhesives and other excipients typically included in the pulp are as such - even without the addition of impregnated stiffeners such as resins - sufficiently rigid to fill optical disks requirements, assuming that they have a sufficient basis weight. The coating layer, in combination with a paper or board web, provides a suitable, flat and rigid substrate.

According to the invention, a planar polymer coating is provided on at least one surface of a coated paper or board sheet 5 comprising two opposed surfaces. The polymer coating is then micro-machined, for example, embossed with a tool, using an embossing plate containing digital data, to produce a high resolution pattern with pits and flat areas on the coating layer.

As is evident from the foregoing, in comparison with known sheets based on thermoplastic substrates such as polycarbonates, the present invention employs a paper or board body which provides the sheet as a whole with limited durability properties. For example, when the board is exposed to air humidity that is different from the board's manufacturing and storage humidity, the board can become curled and become unreadable. Alternatively, the boards can be made from stable materials for an indefinite period of time for environmentally friendly and inexpensive ticdon storage.

Because the invention is environmentally friendly, easy to manufacture, and inexpensive, it can be well used as a DVD disc especially for one-way movie and computer or console game rental. Another field of application of the invention is in medicine. According to recent innovations in blood test methods, blood samples could be analyzed by printing antibodies onto an optical disk, applying blood on the antibodies, and reading the test results optically from the surface of the disk. In this case, the micro-machined pattern, such as embossing, would contain only concentric paths or a pre-groove that would receive the antibodies.

More particularly, the invention is characterized by what is said in the characterizing part of claim 1.

The method is essentially characterized by what is said in the characterizing part of claim 17.

The use is characterized by what is claimed in claim 32.

5

The invention provides considerable advantages. Thus, with the exception of the discrete surface layers of the sheet, the sheets can be pre-fabricated prior to microprocessing, such as embossing, which reduces the need for post-microprocessor sheet transport or the need to centralize manufacturing and micromachining equipment. Further, when, according to one preferred embodiment, the microfabricated layer 5 is applied to the most or one of the top layers, the sheet is not scratch-resistant, which reduces the sheet's collectable value. Alternatively, the polymer layer may be made of an elastic material containing micro-processed data in readable form only for a time proportional to the elasticity of the polymer. The boards can be made from inexpensive materials that have a fully recyclable and environmentally friendly status. Nor is there a need for conventional stiffening methods such as resin impregnation.

The low weight of paper and paperboard boards also offers significant advantages. Low weight reduces in particular the cost of transporting products and the environmental impact. In addition, the shipping costs of discs can be kept low, which is particularly important for, for example, the on-demand movie rental business and similar sweat activities such as video rental over the Internet. Thus, the two major drawbacks of the prior art can be eliminated by the present invention, thus providing a cost effective rental method and an easy and environmentally safe disposal method.

Because the optical disc containing the printed antibodies and blood samples contains sensitive personal information, this disc is easy to dispose of and is valuable. As both of these applications, DVD rental and optical biomedical analyzes, are directed to the general public, the ecological aspects of the present invention which have little or no weight in the prior art are emphasized.

One of the additional advantages of paper and board-based boards is that they can be printed on the top side, i.e., the side which does not contain microprinting, with excellent quality economically. Thus, the appearance of 30 discs can be made very attractive. Ordinary polycarbonate sheets as such are poorly printable. Thus, the top must be processed for printing, but the resolution is still far from the print resolution of paper products. Generally, a separate film can be printed over the polycarbonate sheets, which can be printed, requiring at least one additional step of the manufacturing process.

6

According to one embodiment, the disks are manufactured for writing at home. Writable paper and board based optical discs offer new opportunities for eco-friendly consumption. The life of the discs may be short or long, depending on the materials selected and the storage and use of the discs. Writable discs can be used, for example, in movie rental companies, where the customer can order and print on a cost-effective basis. The process can be easily automated so that, based on user input, one machine burns the data side of the disk, prints the overlay, and encapsulates the disk. After use, the boards are easily recyclable due to the absence or low content of harmful materials.

10

In the following detailed description, embossing is commonly used as an exemplary possible micro-machining technique. However, one skilled in the art will recognize that microstructures may be obtained using other techniques. Such techniques include, for example, electron beam lithography, microlithography, photohtography, ion etching, laser microprocessing, X-ray lithography, wet etching, dry etching, ultraviolet silver printing, diamond engraving, electrospraying and letterpress printing. Generally, the terms "micro-machining" and "high-resolution pattern forming" encompass all methods that can produce optically identifiable micro- or nanoscale structures in a controlled manner on the polymeric coating layer.

The term "disk" and "optical disk" means an optical read or write product comprising an area which is optically compatible with existing disk formats such as CD, CD-R, CD-RW, DVD, DYD-R, DVD + R, DYD- RW, DVD + RW, DVD-RAM, DVD-ROM, 25 HD-DVD or Blu-Ray, or any other flat product that otherwise has a laser beam to read or write.

As used herein, the term "recyclable" must be understood in a broad sense which also includes the term "disposable". Thus, the term "recyclable" refers to a product that can be recycled, that is, its materials can be reused to make another product, the same or different, or a product that can be disposed of in an environmentally friendly way with household or paper waste.

7

The word "carton" is used in a general sense to include all types of paperboard, such as paperboard, carton board, container board and linerboard.

The invention will now be more fully understood by reference to the detailed description and with reference to the accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. and a reflective layer, Fig. 4 is a cross-sectional view of an optical sheet having a coated base layer, a micro-machined polymeric coating layer, a reflective layer, and a protective layer, Fig. 5 showing a cross-sectional view of an optical sheet having a coated base layer, alternatively a micro-machined polymeric coating Figure 7 is a cross-sectional view of an optical sheet having a coated base layer, an alternatively micro-machined polymeric coating layer, a reflective layer and a protective layer.

25

Detailed Description of the Invention

Referring to Figure 1, the recyclable or disposable optical disc of the invention comprises a substrate 18 having two opposed surfaces and a planar polymeric coating layer 16 on at least one of the surfaces such that said substrate consists of a paper or board sheet 12. The paper or board sheet is coated with a suitable coating layer 14 which makes the surface smooth and smooth. The polymeric coating layer contains microprocessed data such as embossed data, such as a digitally encoded video file (s) (video 8 stream) or computer data files, in the form of a high resolution pattern of pits and smooth areas.

Figure 2 shows the structure of Figure 1 in more detail. Figures 3-7 illustrate alternative embodiments. In all of the embodiments shown, the polymeric coating 16, 26, 36.46, 56, 66, 77 is cured on the coated substrate 18, 28, 38.48, 58, 68, 78 and has a micro-machined surface. In the embodiments shown in Figs. 2-4, the micro-machined layer 26, 36, 46 contains a more even area than the well area. Figures 5-7 show embodiments in which the wells are more dominant than the flat areas.

10

According to a preferred embodiment of the invention, the surface of the polymer coated paper or board 18, 28, 38, 48, 58, 68.78 preferably has a surface roughness of 2.0 μιη or less when using a PPS-10 size as defined by ISO 8791-4. This requirement ensures that the surface uniformity is sufficient for a sufficiently even layer of polymer. For the plate 15 to be sufficiently durable for rapid rotation and stiff enough to be optically readable, the substrate preferably has a basis weight of 60 g / m 2 or more, preferably 120 to 550 g / m 2, typically 200 to 400 g / m 2. In some applications, thin and flexible substrates having a basis weight of about 30 to 120 g / m 2 may also be used.

According to one preferred embodiment, the substrate 18,28,38, 48, 58, 68, 78 is self-supporting and planar in the sense of the following two conditions. First, when the plate is rotated at a reading speed about an axis of rotation in an arbitrary spatial position at ground level, at least one surface of the substrate, at any point on the surface or surface, deviates perpendicularly 0.3mm or less from an imaginary reference plane Second, when the plate is rotated at a reading speed about an axis of rotation in an arbitrary spatial position at ground level, at least one surface of the substrate at any point on the surface or surfaces is at an angle of at most 0.15 ° and tangentially to 0.40 ° to an imaginary reference plane ideally planar substrate. Thus, an optical disc made from such a substrate complies in this respect with ECMA-267, 3rd Edition, April 2001 "120mm DVD-ROM - Read-Only Disk" which contains the physical and mechanical characteristics of a standard DVD-ROM.

9

According to an alternative embodiment of the invention, the substrate 18, 28, 38.48, 58, 68, 78 is self-supporting and planar in the sense that at least one of the substrate surfaces supported at any single point at ground level in any spatial position deviates perpendicularly up to 0.3 mm or less, and / or at an angle of at most 0.15 ° in the tangential direction and at an angle of at most 0.40 ° in the radial direction relative to the imaginary reference plane defined by the assumed ideal planar substrate.

According to a further preferred embodiment of the invention, the substrate has a bending stiffness according to ISO 2493 standard 10 of preferably 3.0 mNm or more, especially 10 mNm or more, typically up to 300 mNm in the machine direction and 2.0 mNm or more, particularly 5 mNm or more, typically up to 200 mNm in the transverse direction. .

Requirements for self-supporting, flatness and stiffness ensure the optical readability of the disk. Thus, the reading laser beam provided by the laser source of the turntable is reflected back to the information retrieval means of the player. Examples of suitable substrates are Chromolux 700 (250 g / m2) and Chromolux Magic Chrom (250 g / m2) from M-real Zanders, Germany, Carta Integra (330 g / m2) from M-real Äänekoski Board, Finland, Galerie Art, Gloss (300 g / m2) from M-real Äänekoski Paper in Finland and Tako CX (230 g / m2) from M-real Tako Board in Finland.

20

As mentioned above, the preferred coated paper and board substrates 18, 28, 38, 48, 58, 68, 78 have a basis weight of about 30 to 120 g / m 2 or 120 to 550 g / m 2, depending on the application. They comprise a cellulose-containing web which is coated with a coating color. By "cellulosic material" we mean paper, board or similar cellulosic material produced from lignocellulosic feedstock, particularly wood or annual or perennial plants. The material may be woody or wood-free and may be made from mechanical, semi-mechanical (chemimechanical) or chemical pulp. The chemical or mechanical pulp may be bleached or unbleached. The material may also contain recycled fibers, especially recycled paper or board.

30

The substrate coating layer 14, 24, 34, 44, 54, 64, 74 located on a paper or cardboard sheet 22, 32, 42, 52, 62, 72 comprises a binder containing mineral pigments and additives as is known in the art. The coating layer typically has a basis weight of about 0.5 to 40 g / m / side, particularly 1 to 20 g / m / side. The coating layer may comprise a single-layer coating, a two-layer coating (comprising a pre-coating and a surface coating) or even a three-layer coating or more. In general, the coating color of the present invention contains 10-100 parts by weight of at least one pigment or pigment mixture, 0.1-30 parts by weight of at least one binder and 1-10 parts by weight of other known additives. The binder of the coating layer increases the stiffness of the uncoated sheet of paper or board.

Typical binders are, for example, synthetic latexes made from polymers or copolymers of ethylenically unsaturated compounds, e.g. containing comonomers containing carboxyl groups. It is also possible to use, for example, water-soluble polymers, starch, CMC, casein, soy protein, hydroxyethyl cellulose and polyvinyl alcohol as binders. Examples of pigments include precipitated calcium carbonate, powdered calcium carbonate, calcium sulfate, calcium oxalate, calcium sulfoaluminate, calcium silicate, talc (aqueous magnesium silicate), amorphous silicates, titanium dioxide and theirs. Synthetic pigments such as polymer / plastic pigments may also be used to improve gloss and smoothness. The most important of the above pigments are kaolin, calcium carbonate, precipitated calcium carbonate and gypsum, which generally make up more than 50% of the dry solids in the coating composition. Calcined kaolin, titanium dioxide, gloss white, aluminum hydroxide, sodium silicoaluminate and plastic pigments are additional pigments and are generally present in less than 25% solids in the blend. Special pigments which may be mentioned are special kaolins and calcium carbonates, as well as barium sulphate and zinc oxide.

The coating color is applied in a known manner on a material web, for example, by means of a blade coating, a film coating, an air knife coating, a spray coating, a spray coating or a dry spin coating.

Thanks to the coating layer, the surface uniformity at a later stage of the manufacturing process is sufficient to apply a thin polymer layer which can be micro-machined, for example by embossing. The surface roughness is then preferably 20 μηι or less according to PPS-10.

11

Although in a preferred embodiment of the invention the substrate 18,28,38,48, 58,68,78 consists of a single sheet of coated paper or board, we do not exclude embodiments having a plurality of sheets of paper or board affixed to one another. for example by adhesive bonding to form a thicker and stiffer substrate.

The above described substrate 18, 28, 38.48, 58, 68.78 is further stolen with a polymeric layer 16.26, 36.46, 56, 66.76 applied to at least one surface of the substrate. Preferably, the polymer is capable of accepting an optically readable pattern, for example DVD resolution, made for example by embossing. In particular, by using a polymeric layer comprising polymethyl methacrylate, polylactide, polyvinyl alcohol (PVA), polystyrene such as Celvol 310 or DPP 3720, a dense and impermeable surface is obtained having sufficient smoothness to receive high resolution digital data, for example, in relief. Alternative preferred materials that can be used in the polymeric layer are non-vinylic natural polymers carboxymethylcellulose (CMC) and starch and derivatives thereof. The advantages of PVA and polylactide are that they are completely biodegradable.

In an alternative embodiment, the material used in the polymeric coating layer 20 16.26, 36.46, 56, 66, 76 is an elastic polymer, for example a copolymer of styrene-butadiene. By controlling the proportion of butadiene, the elasticity of the polymer can be adjusted. Suitably adjusted elasticity allows the data to be processed, for example, by embossing on the coating, but fading into an optically illegible form as the polymer searches for its mini-energy state mainly over a period of time determined by polymer properties and ambient temperature conditions. The temperature dependence of fading can be utilized to limit the life of the discs, as the reading laser warms the surface of the disc as it is read.

The polymeric coating layer 16, 26, 36, 46, 56, 66, 76 may contain additives such as Pigment-30s to alter the optical properties of the layer, in particular refractive index and / or reflectance or, alternatively, color or mechanical properties such as embossing. Examples of optical (scattering) additives are titanium dioxide, zinc sulfide, metal particles and mixtures thereof. Other pigments include precipitated calcium carbonate, powdered calcium carbonate, calcium sulfate, calcium oxalate, calcium sulfoaluminate, aluminum silicate, kaolin (aqueous aluminum silicate), aluminum hydroxide, magnesium silicate, talc (anhydrous), Typically, the polymeric layer of the invention may contain, for example, 50 to 100 parts by weight of a polymeric binder, 5 to 100 parts by weight of at least 5 pigments or a pigment mixture, and 1 to 10 parts by weight of other known additives and excipients. Other additives and excipients include, for example, dispersants (e.g., sodium salt of a polyacylic acid), substances which affect the viscosity of the polymer composition and water resistance (e.g., CMC, hydroxyethyl cellulose, polyacrylates, alginates, benzoate), so-called lubricants (e.g. 10 esters, amines, calcium or ammonium stearates), hardeners used to improve water resistance (eg glyoxal), antifoam agents (eg phosphate esters, silicones, alcohols, ethers, vegetable oils), pH adjusting agents (eg sodium hydroxide, ), and preservatives (e.g., formaldehyde, phenol, quaternary ammonium salts). The use of pigments, in particular optical auxiliaries, and other additives and auxiliaries, aims to achieve the dispersion and high resolution of the polymer layer, such as embossing, and the optical readability of the data on the disk.

The polymer layer 16,26,36,46, 56,66, 76 is preferably applied to the substrate using an aqueous dispersion, dissolved, melted or powdered, for example by sputtering.

In one embodiment, the surface is calendered in a separate process using, for example, a calender or a comparable device suitable for the polymer in question to form a uniform polymer film and to achieve sufficient uniformity for microprocessing, for example, embossing. If necessary, intermediate treatment steps such as heat treatment between polymer application, such as dispersion, and calendering may be performed. Similarly, further process steps can also be performed after calendering. As a result of the above operations, the polymeric coating preferably has a basis weight of 10,26,36,46,56,66,66, 10 g / m 2 or less, in particular 0.1-5 g / m 2, and a layer thickness in the range of about 0.1 to 30 10 µιη.

In one embodiment, the polymeric coating 16, 26, 36, 46, 56, 66, 76 is not calendered after application. In this embodiment, sufficient surface uniformity (especially its range) is achieved in the micro-machining step. For example, an embossing tool 13 that can be used for microprocessing a polymeric layer may at the same time serve as a flat calender or a calender depending on the type of tool. Also in this embodiment, the sheet can be pre-treated, such as heated, prior to microprocessing.

Although in a typical embodiment of the invention the substrate comprises a polymeric coating 16, 26, 36, 46, 56, 66, 76 for a micro-machined pattern formed, for example, by embossing only on one surface of a sheet of paper or board, we do not exclude the possibility of layer and patterned, for example, by embossing on two opposed surfaces using, for example, the methods described above.

Referring to Figures 3 and 6, in one preferred embodiment of the invention, at least one additional coating layer, such as a reflective metal layer 37, 67, may be applied over a microprocessed, such as embossed, polymeric layer. The reflective layer may, for example, consist of sput-15 sharpened aluminum, silicon, gold or silver. Instead of sputtering, the layer can be applied by resistive evaporation of, for example, aluminum, silicon, gold, silver, or a mixture of these. The purpose of the reflective layer is to achieve sufficient reflectivity of the microprocessed surface such as embossed printing to enable optical reading of the disc by data reading means such as a DVD player, a CD player or a computer.

20

Referring now to Figures 4 and 7, in one embodiment, the polymeric layer 46, 76, and optionally the reflective layer 47, 77, is coated with other polymeric components to form a protective polymeric layer or layers 49, 79. One of the additional layers 49, 79 serves to protect the microprint on the surface of the first polymer layer 46,76 or possibly the reflective layer 47,77. For example, a protective layer 49, 79 may be added to make the sheet better scratch resistant. The optical properties of the sheet can also be influenced by the layer 49, 79. Thus, the compatibility of the disc with conventional players can be improved. The protective layers 49, 79 may be applied in solutions or melted, i.e. in liquid state. In particular, when a polar polymer such as PVA is used in the first-to-30 polymeric coating layer 46, 76, which is microprocessed, it may preferably be covered with a non-aqueous solution comprising, for example, polylactide. The polylactide varnish may be applied in a nonpolar or weakly polar solvent such as acetone. The lacquer layer can be dried or cured by heating or UV light.

14

According to one embodiment, the polymeric coating layer 16, 26, 36, 46, 56, 66, 76 contains a data stream formed, for example, from engravings of various sizes arranged in a spiral shape. Thus, the polymeric layer may have less area occupied by the wells than the flat surface (ridges), as illustrated in Figures 2-4. Alternatively, in step 5, the micrograph may contain more wells than ridges, as illustrated in Figures 5-7. Which of these options is used depends on the application. Influential factors include, for example, the desired optical format of the disc, the type of player used to read the disc, the layer structure of the disc, and the micro-processing method.

According to one embodiment, the plate is micro-machined by planar embossing using an embossing plate which contains a negative microstructure negative to the plate. The embossing pressure and temperature will depend on the polymer and substrate used, the resolution of the embossing desired, and the properties of the embossing board such as material and uniformity. In addition to embossing, optically readable structures may be formed by any of the other processing techniques listed elsewhere in this document. According to one embodiment, the micro-machining is performed by means of a roll-relief printing process.

In one embodiment, at least part of the micro-machined pattern in the polymer layer 16, 26, 36, 46, 56, 66, 76 is formed by a spiral pre-groove without the actual 20 data. Prefix is used to help turntables stay on track while the disc is being read or written.

According to one embodiment, the discs are user-writable, for example, with standard CD or DVD drives. In this embodiment, a helical pre-groove is formed on the polymeric coating layer 25 16, 26, 36.46, 56, 66, 76. A good reflective layer can be added over it. After that, the groove is filled with embroidery dye that is sensitive to laser light. The protective layer can be added to the top. For example, the polymeric coating layer and the protective layer may be as described above, but they may also be modified to fit better with the dye layer. In particular, optical auxiliaries or other substances mentioned above may be added to the polymer to increase its reflectivity. Exemplary dyes include cyanine, phthalocyanine, carbocyanine, and metal complex dyes. In addition to physical protection, the protective layer may also chemically protect the sheet to protect the dye layer, for example, from oxygen or moisture. The physical dimensions of the front groove and the type of toner depend on the disc format desired. Also in this embodiment, a reflective layer can be applied, either before or after the dye layer. Thus, a disc according to this embodiment may be, for example, a recordable or rewritable CD, DVD, or Blu-Ray disc. For example, in the movie rental business, discs can be equipped with some kind of self-destruct mechanism that triggers when the disc is being written or read, or the 5 disc case is opened. Disks can also be tampered with some non-changeable precursor data, such as ads or security or authentication features.

According to one embodiment, the sheet is permanently attached to a substrate larger than the size of the sheet. In this case, for example, the area of the micro-machined region is 10 to 99% smaller than that of the actual substrate. For example, the disc may be made of cardboard, which forms a passport cover page or an ID card. In this embodiment, the disc may include biometric identification of the card holder, such as a fingerprint, face image, signature, or iris pattern. The dimensions of the disc may be much smaller than those of conventional optical discs, for example 1 to 5 cm. The capacity of such disks can be 15, for example 0.1 to 100 MB. The shape of the disk with a vortex is also non-circular, since, for example, the passport is difficult to rotate in the reader. For example, the data may be microprocessed into a rectangular matrix which is read line by column in a special reader. The data may also be in a special format and / or encrypted. The passport page containing the embedded board may also be coated or laminated to prevent the board from being worn. The biometric identification feature implemented in this manner would provide as good or even better security level than the microcircuit based features used today. In addition, the data capacity could be many times the capacity of the integrated circuits. Optically readable data would also not be destroyed in high electric or magnetic fields.

The data of irreversibly integrated discs can be micro-machined, for example, with letterpress printing, or the discs can be fabricated for laser-writing. In one embodiment, the disk comprises both a preprocessed data area for maximum security and a laser-processed data area for maximum flexibility. For example, in key cards, the preprocessed region may contain hard-to-fake employer information and the laser-30 preprocessed region may include biometric information about the employee, his or her status, his or her rights, and so on. Employee information can be written using appropriate equipment at the workplace by the company's security department.

EXAMPLES Example 1 A polyvinyl alcohol dispersion (Celvol 310) was applied to a coated Chromolux 700 (250 g / m 2) cardboard as a single layer by rod coating. The coating weight was about 2 g / m2. At this point, the layer looked opaque.

The coated paper was then treated in an oven at 150 ° C for 60 minutes.

10 The heat treatment made the layer transparent. The next step is calendering with 95 kN / m nip pressure, 50 ° C cash temperature and three presses, which further increased the gloss of the surface due to the additional leveling of the surface layer. The end result was a visually transparent and even surface layer. Atomic force microscopy (AFM) showed that the surface was also homogeneous at the micrometer level.

15

Horizontal thermal embossing was performed using a 35 ton pressure at 45 ° C. The printing time was 30 seconds. The embossing board was in direct contact with the carton. The result was visually observable micro-level patterns on the surface. The study by electron scanning microscope 11a proved that the linear gratings of 6.4 μιη ^ 0.2 μπι: ϋη 20 were clearly and perfectly reproduced on the surface of the treated board.

Example 2

Polystyrene dispersion (DPP 3720 - particle size 200 nm) for application on coated Chro-25 molux 700 (250 g / m 2) cardboard in a single layer. The dispersion had a solids content of 30% by weight and a weight of the applied coating of about 2 g / m 2. At this stage, the layer was opaque.

The board was then treated in an oven at 150 ° C for 120 minutes. The Appliko germ layer had now become transparent and atomic force microscopy (AFM) showed that the individual polystyrene particles had consolidated into a homogeneous film. Calendering at a nip pressure of 95 kN / m and a rally temperature of 80 ° C with three presses increased the gloss of the surface even more due to additional leveling of the surface, which was confirmed by atomic microscopy.

17

Horizontal thermal relief printing was performed using a 28 ton pressure at 70 ° C. The printing time was 30 seconds. The embossing board was in direct contact with the carton. The result was visually observable micro-level patterns on the surface. Examination of the surface with 5 electron scanning microscopes proved that the linear gratings of 6.4 μιη ^ 0.2 μηκϋη were clearly and perfectly reproduced on the surface of the treated board.

Claims (32)

A recyclable optical disk comprising - a substrate (18) having two opposing surfaces and having at least one surface provided with a flat polymeric coating layer (16), and - a high-resolution pattern formed in said coating layer (16), and the substrate comprising a coated paper or cardboard sheet (12, 14), characterized in that the substrate coating comprises at least one pigment coating layer, whereby said polymeric coating layer is located. Optical disk according to claim 1, characterized by the high resolution pattern formed by embossing. Optical disk according to claim 1 or 2, characterized by the PPS-10 surface roughness (ISO 8791 -4) of the surface of the substrate approaching the polymeric coating layer (16) at 2.0 µm or less. Optical disk according to any of the preceding claims, characterized in that the square meter weight of the substrate (18) is up to 30 - 120 g / m2. Optical disk according to any of the preceding claims, characterized in that the square meter weight of the substrate (18) is up to 120 - 550 g / m. Optical disk according to any of the preceding claims, wherein the bending stiffness of the substrate (18) is ISO 1093 or more in the machine direction and to 5 mNm 20 or more in the transverse direction. Optical disk according to any of the preceding claims, characterized in that the substrate (18) is self-supporting. Optical disk according to any of the preceding claims, characterized in that the polymeric coating layer (16) comprises a layer of polyvinyl alcohol, polystyrene, polymethylmethacrylate, polylactide, CMC or starch. 23 Optical disk according to any of the preceding claims, characterized in that the polymeric coating layer (16) comprises a layer of some elastic polymer, e.g. styrene-butadiene, and the elasticity of the polymer is controlled by its composition. Optical disk according to any of the preceding claims, characterized in that the polymeric coating layer (16) contains additives, e.g. optical auxiliary pigments, such as titanium oxide, zinc sulfide or mixtures thereof. Optical disk according to any of the preceding claims, characterized in that the weight of the polymeric coating layer (16) is up to 10 g / m2 or less, preferably to 0.1-5 g / m2. Optical disk according to any of the preceding claims, characterized in that it comprises one or more additional coating layers (37, 47, 49, 67, 77, 79), such as a reflective metal layer, on the polymeric coating layer (16). Optical disk according to any of the preceding claims, characterized in that the high-resolution pattern comprises a cutter and the cutter is filled with a writing dye to enable data to be written to the disk by laser light. Optical disc according to any of the preceding claims, characterized in that the optical disc consists of a '' read only '', writable or ether-writable CD, DVD, HD-DVD or Blu-Ray disc. Optical disk according to any of the preceding claims, characterized in that said substrate (16) is larger than the size of the disk. Optical disk according to any of the preceding claims, characterized in that it comprises printed antibodies on the polymeric coating layer (16) or on the said additional coating layer (s) (37, 47, 49, 67, 77, 79). . 17. A method of manufacturing a recyclable optical disk, wherein method 25. a substrate (18) with two opposing surfaces is selected, - a flat polymeric coating layer (16) is provided on at least one surface, 24 - a high-resolution pattern is formed on said coating (16), and - as said substrate is used, coated paper or cardboard (12, 14), characterized by dewatered substrate, the coating of which comprises at least one pigment coating layer, whereby said polymeric coating layer is provided. 5 18. A method according to claim 17, characterized by the high resolution pattern being formed by embossing. Method according to claim 17 or 18, characterized in that a substrate (18) is used, whose PPS-10 surface roughness (ISO 8791 -4) is up to 2.0 µm or less at least on one surface of the substrate (18). 10 20. A method according to any of claims 17-19, characterized in that a substrate (18) whose quadrometer weight ranges from 30 to 120 g / m2 is used. 21. A method according to any of claims 17-20, characterized in that a substrate (18) whose quadrometer weight ranges from 120 to 550 g / m2 is used. Method according to any of claims 17-21, characterized in that a substrate (18) whose bending stiffness (ISO 2493) projects up to 10 mNm or more in the machine direction and to 5 mNm or more in the transverse direction is used. A method according to any of claims 17 to 22, characterized in that a self-supporting substrate (18) is used. Process according to any of claims 17-23, characterized in that as the material of said polymeric coating layer (16), polyvinyl alcohol, polystyrene, polymethylmethacrylate, polylactide, CMC or starch are used. 25. A method according to any of claims 17 to 24, characterized in that, as the material of said polymeric coating layer (16), some resilient polymer such as styrene-butadiene is used, and the elasticity of the polymer is controlled by its composition. 25 Process according to any of the claims 17-25 characterized in that the polymeric coating layer (16) contains additives, e.g. optical auxiliary pigments, such as titanium dioxide, zinc sulfide or mixtures thereof. 27. A method according to any of claims 17-26, characterized in that it comprises at least one intermediate process step, such as heat treatment, between the provision of the polymeric coating layer and the formation of said high-resolution pattern. 28. A method according to any of claims 17-27, characterized in that it comprises applying an at least one additional coating layer (37, 47, 49, 67, 77, 79), as a reflective metal layer, to the embossed polymer layer. A method according to any of claims 17-28, characterized in that a pre-cut is formed on said polymeric layer (16) and the pre-cut is filled with a print color to enable data to be written to the disc by laser light. A method according to any of claims 17 to 29, characterized in that a protective polymeric layer is provided on said polymeric coating and said dye. Method according to any of claims 17-30, characterized in that a substrate (18) larger than the size of the disc is used. The use of a pigment-coated paper or cardboard sheet (12, 14), whose at least one surface exhibits a polymeric layer (16) which accepts an optically readable pattern, such as substrate (18) for a recyclable disk.