JP3444748B2 - Optical disk printing method - Google Patents

Description

Description: BACKGROUND OF THE INVENTION [0001] The present invention relates to an electrophotographic system.
The present invention relates to an optical disk printing method . More specifically, electrons print the images in electrophotographic method on the surface of the optical <br/> disc
The present invention relates to a method for printing an optical disk by a photographic method . [0002] Ultraviolet curable resin inks are excellent in heat resistance, water resistance and the like, and are widely used for protecting and coloring the surfaces of optical discs and resin bottles by applying them to the surfaces thereof. I have. For example, an ultraviolet curable resin ink applied on an optical disk is used to prevent oxidation of an aluminum film deposited on a disk substrate made of polycarbonate or the like. The ultraviolet curable resin ink is also generally used when coloring the surface of an optical disk, a bottle, or the like by offset printing, screen printing, or the like. Further, when the surface of an optical disk or a bottle is covered with an ultraviolet curable resin ink, it is also useful for modifying the surface of the optical disk or for making up the surface. [0004] However, the conventional ultraviolet curable resin ink does not originally have conductivity, and the coated surface formed by coating has an extremely high surface resistance of 1 × 10 ¹⁵ Ω or more. Therefore, when an image is to be printed on a coated surface formed by applying the ultraviolet curable resin ink by an electrophotographic method, for example, a method described in JP-A-64-38237. There is a disadvantage that the image cannot be transferred favorably onto the coated surface of the ultraviolet curable resin ink. [0005] [SUMMARY OF THE INVENTION The present invention, wherein has been made in view of the prior art, after applied to the surface of the optical disc, transferability by an electrophotographic method on coating Kumen An object of the present invention is to provide a method of printing an optical disc that can form an image well. [0006] Means for Solving the Problems That is, the gist of the present invention, a needle-like, an ultraviolet curable resin ink you containing a conductive filler having an aspect ratio of 2 or more 5 to 50 wt%
Coating on the surface of an optical disc, and reducing the surface resistance of the coated surface to 1
× 10 ¹³ Ω or less, and then electrophotographed on the coated surface
An electrophotographic method characterized by printing more images
The present invention relates to an optical disk printing method . [0007] The ultraviolet curable resin ink of the present invention contains a conductive filler as described above. [0008] The conductive filler may be either a metallic conductive filler or a non-metallic conductive filler. Examples of the metal-based conductive filler include a conductive filler made of a metal such as gold, silver, copper, aluminum and nickel, and a conductive filler made of an alloy of these metals. As the nonmetallic conductive filler, for example, zinc oxide, aluminum borate, barium sulfate,
Titanium oxide, tin oxide, potassium titanate, zinc oxide,
Indium oxide, indium oxide / tin oxide composite oxide (ITO), tin oxide / antimony oxide composite oxide (A
Conductive fillers made of non-metallic materials such as TO). The shape of the conductive filler is not particularly limited, and may be a true sphere or a different shape.
Among the conductive fillers having such a shape, an acicular conductive filler having an aspect ratio [maximum side length (L) / diameter (D)] of 2 or more easily forms a two-dimensional conductive chain on a coating surface, Since the surface resistance of the coated surface can be reduced by adding a small amount of the conductive filler, it can be suitably used in the present invention. The size of the conductive filler varies depending on its shape and the like.
It is preferably about μm. The conductive filler has a resistance value of 1 × 10 ¹⁰ Ω or less from the viewpoint of forming a good image by an electrophotographic method on a coating film formed by applying the obtained ultraviolet curable resin ink. It is preferred that The conductive filler can be used in the same manner as a pigment used in a conventional colored ultraviolet curable resin ink. [0015] The content of the conductive filler in the ultraviolet curable resin ink is 5% by weight from the viewpoint of securing a surface resistance capable of forming an image with good transferability on the coated surface of the ink by an electrophotographic method. % Or more, preferably 7% by weight or more, and when the coated surface of the ink is cured with ultraviolet rays, from the viewpoint of improving the curability and the degree of curing, it is preferably 50% by weight or less, preferably 35% by weight. % Is desirable. As the UV-curable resin ink, any conventionally used UV-curable resin ink may be used. Examples of the ultraviolet-curable resin ink include an ultraviolet-curable resin ink generally used for an undercoat of an optical disk and an ultraviolet-curable resin ink used for screen printing and offset printing. The ultraviolet curable resin generally comprises a polymerization reactive resin, a cut monomer, a photopolymerization initiator, and other additives. Specific examples of the monomers used for the polymerization reactive resin include, for example, acrylic esters, epoxy acrylates, urethane acrylates, polyester acrylates, polyether acrylates, alkyd acrylates, polyol acrylates, polyurethane acrylates and melanin acrylates. can give. Examples of the cut monomer include monoacrylate, diacrylate, and triacrylate, and the cut monomer can be used for adjusting the viscosity. Examples of the photopolymerization initiator include benzoin, acetophenone, benzyl ketal and the like. Examples of the additives include additives usually added for improving the storage stability of ink and the dispersibility of pigments, as well as pigments such as general inorganic pigments and organic pigments. And those used in conventional colored ultraviolet curable resin inks. In using the pigment, a part or all of the pigment may be replaced with a combination of the conductive filler and another dye instead of using the pigment. By mixing the polymerization reactive resin, cut monomer, photopolymerization initiator, and other additives in desired amounts, an ultraviolet curable resin can be obtained. The method for producing the ultraviolet-curable resin ink is not particularly limited, and may be generally the same as the method for producing a conventional ultraviolet-curable resin ink. The ultraviolet curable resin ink of the present invention can be obtained by adding a predetermined amount of the conductive filler to the ultraviolet curable resin ink. The UV-curable resin ink of the present invention can be used by mixing with other inks, if necessary. The surface resistance of the coated surface formed by applying the ultraviolet-curable resin ink of the present invention to an object to be coated is determined from the viewpoint of forming an image with good transferability by electrophotography on the coated surface of the ink. 1 × 10 ¹³ Ω or less, preferably 1 × 10 ¹³ Ω
It is desirable to be ¹¹ Ω or less. Such surface resistance can be achieved by appropriately adjusting the amount of the conductive filler to be added. In the present invention, the surface resistance of the film is determined by Advantest Co., Ltd. under the trade name of Resistivity Champa R in accordance with JIS-K6911.
12704 (main electrode diameter 50 mm, guard ring inner diameter 70 mm, guard ring outer diameter 80 mm, counter electrode 11
0 × 110 mm) and a product made by Advantest Co., Ltd., trade name: digital super resistance / micro ammeter R8340A, when measured in an atmosphere with an applied voltage of 100 V, an ambient temperature of 23 ° C. and a relative humidity (RH) of 50%. Is the value of There is no particular limitation on the method of applying the ultraviolet-curable resin ink to an object to be coated such as an optical disk. Specific examples of such a method include a spin coater method, a screen printing method, an offset printing method, and the like. Pad printing, roll coating and the like can be mentioned. Examples of the object to be coated include so-called C
Commonly used optical disks such as D, CD-ROM, CD-R, and LD are exemplified. The thickness of the coating film when applying the ultraviolet-curable resin ink to the object to be coated is not particularly limited, but is usually about 5 to 20 μm in consideration of coating film strength and surface smoothness. It is preferred that After the coating film of the ultraviolet curable resin ink is formed in this manner, for example, Japanese Patent Application Laid-Open No. 64-382
By the electrophotographic method described in No. 37,
Printing can be performed on the coating film. When an optical disk is used as the object to be coated and label printing is performed on the surface of the optical disk by electrophotography, for example, a commonly used laser beam printer or the like can be used. In the case where the laser beam printer is used, for example, the clearance between the upper and lower feed rollers of the conveyance section of the printing material is removed in order to remove the fixing portion and not to hinder the passage of the optical disk. Is adjusted according to the thickness of the optical disk, and the clearance between the toner image support (transfer belt) and the transfer roller at the transfer portion is adjusted to reduce the stress at the time of contact. It is possible not to hinder the passage. It is preferable to provide a high-voltage power supply outside the laser beam printer so that the transfer voltage at the time of transferring the toner image to the optical disk can be appropriately adjusted. The transfer voltage and current are not particularly limited. Usually, the transfer voltage may be about 500 V to 6 kV, and the current may be about 0.5 to 5 mA. In order to easily adjust the fixing temperature at the time of fixing the toner image to the optical disk, for example, the surface temperature of the heat roll at the fixing portion of the laser beam printer is removed. A thermocouple for measuring the surface temperature may be attached so that the surface temperature can be adjusted by a temperature controller. The nip pressure can be adjusted to an appropriate value by adjusting the pressing force of the press roll, for example, by appropriately selecting the type of spring. The conveyance speed at the time of fixing can be adjusted, for example, by modifying the heat roll with a motor capable of adjusting the speed so that a predetermined driving force is applied to the heat roll. Thus, label printing can be performed on the surface of the optical disk by electrophotography. The printed image formed on the surface of the optical disk in this manner is free from transfer failure and image disorder.
It has high quality. As described above, when the ultraviolet curable resin ink is coated on the object to be coated and printed on the formed coated surface, the image can be transferred well. it can. Next, the present invention will be described in more detail based on examples, but the present invention is not limited to these examples. Production Example 1 As an optical disk molding resin, a polycarbonate pellet (about 2 mm in diameter and about 3 mm in length) was put into a kneader, heated to 300 ° C. to prepare a melt-kneaded product, and then injected into an optical disk molding machine. , Diameter 120mm, thickness 1.2
mm optical disc substrate was molded. A reflective film is formed by depositing aluminum on the obtained optical disk substrate, and an antioxidant film (thickness: about 10 μm) is formed with an ultraviolet curable resin in order to prevent oxidation of the reflective film. I got an optical disk. Example 1 75 parts by weight of an ultraviolet curable resin ink (manufactured by Teikoku Ink Manufacturing Co., Ltd., trade name: Aqua UVMAX ink) and acicular conductive titanium oxide (trade name: FT-, manufactured by Ishihara Sangyo Co., Ltd.) 30
(00, aspect ratio: 19.1, resistance value: 30Ω) 25 parts by weight was stirred with a homomixer for 30 minutes to obtain an ultraviolet curable resin ink. The obtained ultraviolet-curable resin ink was screen-printed on the optical disk obtained in Production Example 1 so that the thickness of the image-formed portion after drying was about 10 μm (interval between openings: 300 mesh). ). The surface resistance of the formed image was measured at a temperature of 23.
When measured in an atmosphere at 50 ° C. and a relative humidity (RH) of 50%, it was 4.7 × 10 ⁶ Ω. Next, the fixing portion of a laser beam printer (manufactured by Sony Tektronix Co., Ltd., product name: Phaser 550J) is removed, and in order to allow the optical disc to be conveyed in the conveying section satisfactorily, the optical disc passing portion is removed. A transfer roller (secondary transfer roller) for extending the clearance and transferring the toner image from the toner image support to the printing material using a toner (a product of Sony Techtronics Co., Ltd., product name: Phaser 550J). ) Can be adjusted by providing a high-voltage power supply outside the laser beam printer. Further, a speed control motor is provided for driving the heat roll of the removed fixing portion so that the conveyance speed can be appropriately adjusted. Further, in order to be able to adjust the fixing temperature to a predetermined temperature, a thermocouple is attached to the surface of the heat roll, and the temperature can be adjusted to a predetermined temperature by a temperature controller. Further, the nip force Ri <br/> by a force pressing the press roll to the heat roll and also adjust the spring, with a printing device which can be adjusted (external fixing machine). Next, after adjusting the secondary transfer voltage and the current to 750 V and 1 mA, respectively, the toner image is transferred to the optical disk, and the feed speed of the optical disk of the external fixing device is 30 mm / sec, and the surface temperature of the heat roll is 160. With the nip force set at 10 ° C. and the nip force adjusted to 10 kg when the optical disk was not passed, the optical disk was passed twice and level printing was performed on the surface of the optical disk. On the obtained optical disk on which label printing was performed, the printed image was free from poor transfer and image disturbance, and was able to be uniformly printed with good transferability and good label printing. Example 2 82.5 parts by weight of an ultraviolet curable resin ink (manufactured by Teikoku Ink Manufacturing Co., Ltd., trade name: Aqua UVMAX ink) and acicular conductive titanium oxide (trade name, manufactured by Ishihara Sangyo Co., Ltd.) F
(T-3000, aspect ratio: 19.1, resistance value: 30Ω)
Five parts by weight were stirred with a mixer for 30 minutes to obtain an ultraviolet-curable resin ink. Using the obtained ultraviolet curable resin ink, an image was formed in the same manner as in Example 1, and the surface resistance was measured to be 1.4 × 10 ⁸ Ω. After that, when an image was formed by an electrophotographic apparatus in the same manner as in Example 1, the printed image was uniform on the optical disk on which the label printing was performed without transfer failure or image disorder. In this state, good label printing could be performed with good transferability. Example 3 90 parts by weight of an ultraviolet curable resin ink (manufactured by Teikoku Ink Manufacturing Co., Ltd., trade name: Aqua UVMAX ink) and acicular conductive titanium oxide (trade name: FT-, manufactured by Ishihara Sangyo Co., Ltd.) 30
(00, aspect ratio: 19.1, resistance: 30Ω) 10 parts by weight with a homomixer for 30 minutes to obtain an ultraviolet-curable resin ink. Using the obtained ultraviolet curable resin ink, an image was formed in the same manner as in Example 1, and the surface resistance was measured to be 2.9 × 10 ¹² Ω. After that, when an image was formed by an electrophotographic machine in the same manner as in Example 1, the printed image was uniform on the optical disk on which the level printing had been performed without transfer failure or image disorder. In this state, good label printing could be performed with good transferability. Example 4 95 parts by weight of an ultraviolet curable resin ink (manufactured by Teikoku Ink Manufacturing Co., Ltd., trade name: Aqua UVMAX ink) and acicular conductive titanium oxide (trade name: FT-, manufactured by Ishihara Sangyo Co., Ltd.) 30
(00, aspect ratio: 19.1, resistance value: 30Ω) 5 parts by weight was stirred with a homomixer for 30 minutes to obtain an ultraviolet curable resin ink. An image was formed using the obtained ultraviolet-curable resin ink in the same manner as in Example 1, and the surface resistance was measured to be 1.0 × 10 ¹³ Ω. After that, when an image was formed by an electrophotographic machine in the same manner as in Example 1, the printed image was uniform on the optical disk on which the level printing had been performed without transfer failure or image disorder. In this state, good label printing could be performed with good transferability. Comparative Example 1 Only an ultraviolet-curable resin ink (trade name: Aqua UVMAX ink, manufactured by Teikoku Ink Manufacturing Co., Ltd.) was stirred with a homomixer for 30 minutes to obtain an ultraviolet-curable resin ink. Using the obtained ultraviolet curable resin ink, an image was formed in the same manner as in Example 1, and the surface resistance was measured to be 3.2 × 10 ¹⁵ Ω. After that, when an image was formed by an electrophotographic machine in the same manner as in Example 1, the image was uneven. [0062] According to the present invention, purple on the surface of the light disc
After applying the external curable resin ink, an effect is obtained in which a predetermined image can be formed with excellent transferability by electrophotography on the applied surface.

──────────────────────────────────────────────────続 き Continuation of the front page (56) References JP-A-51-42606 (JP, A) JP-A-57-95883 (JP, A) JP-A-59-20305 (JP, A) JP-A 64-64 81872 (JP, A) JP-A-5-311103 (JP, A) JP-A-6-157964 (JP, A) JP-A-49-28349 (JP, A) JP-A-3-82899 (JP, A) JP-A-58-5369 (JP, A) JP-B-46-7779 (JP, B1) (58) Fields investigated (Int. Cl. ⁷ , DB name) C09D 11/10 G03F 7/038 501

Claims (1)

(57) in [Claims] [Claim 1] acicular aspect ratio is electrically <br/> conductive filler to a UV-curable resin inks of the optical disc that containing 5 to 50 wt% 2 or more Coating on the surface, the surface of the coated surface
After reducing the sheet resistance to 1 × 10 ¹³ Ω or less, the electron
Optical discs characterized by printing images by photographic methods
Screen printing method .