JP4414549B2 - Method for producing colorant for optical recording medium - Google Patents

Description

【００５６】
表１に示す実施例１〜４に対応に対応する評価として、前述した精製を行っていない染料を使用し、この染料を可塑剤に混合して微細化と分散を行って得た未精製の着色剤▲１▼、▲２▼、▲３▼を作り、これをポリカーボネート樹脂に混合してディスク基板を成形し比較した。その結果を表２に示す。
【００５７】
【表２】

【００５８】
この結果からも、明らかなように、未精製の着色剤を用いて作製したディスク基板は、光ディスクに用いるものとしての十分な光学特性を得ることができなかった。
【００５９】
【発明の効果】
上述したように、本発明を用いることにより、媒体全体を均一に着色し、しかも信号読み取り特性などの光学特性の劣化を招くことない光記録媒体を得ることができる。
【図面の簡単な説明】
【図１】本発明に係る着色剤を精製する装置を示す図である。
【符号の説明】
１ 貯留タンク、 ２ 加熱ポンプ、 ３ 加熱濾過フィルター、 ４ 冷却タンク。[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a method for producing a colorant used for coloring a disk substrate constituting an optical recording medium.
[0002]
[Prior art]
Conventionally, as an information signal recording medium, an optical disc that records an information signal using a light beam or reads out the recorded information signal is used.
[0003]
In this type of optical disc, there are provided those in which an audio signal is recorded exclusively and in which a video signal is recorded together with the audio signal. Furthermore, optical discs are provided in which a program for controlling the operation of an information processing apparatus such as a computer is recorded, or in which video game game software or the like is recorded. As described above, the optical disc is widely used as a recording medium for various information signals.
[0004]
Incidentally, in this type of optical disc, while a common diameter and thickness, are those differing in recorded information and recording format. In particular, optical signals having different recording formats cannot record and / or reproduce information signals using a common recording and / or reproducing apparatus.
[0005]
Therefore, in order to make it possible to immediately identify the recorded information and the recording format, it has been proposed that the disk substrate is colored and the type of the optical disk can be identified by this coloring.
[0006]
Here, as a method of coloring the synthetic resin material constituting the disc substrate of the optical disc, for example, there is a method of obtaining a colored molded product with a molding machine after obtaining a coloring compound. As another method, a powdery colorant called dry color is mixed by a dry blend method in which an uncolored synthetic resin material is mixed, and the synthetic resin material mixed with the colorant is melted to be an injection molding machine. There is a method of obtaining a colored molded article by dispersing the colorant in the molded article by injection and molding. Further, there is a method in which a coloring agent called a master patch in which a high concentration dye and pigment are dispersed is diluted with an uncolored synthetic resin material and colored. Furthermore, a paste-like colorant in which a dye is dispersed in a liquid vehicle is mixed with a synthetic resin material while being quantitatively supplied by a pump or the like, and the synthetic resin material mixed with this colorant is used with an injection molding machine or the like. There is a method of obtaining a colored molded body.
[0007]
[Problems to be solved by the invention]
In general, since a dye has a property of easily dissolving in a synthetic resin, a colored molded body can be easily obtained by using any of the methods described above.
[0008]
By the way, in an optical recording medium such as an optical disk, it is necessary to prevent optical characteristics from being deteriorated by coloring agents and impurities contained in the coloring agents when coloring is performed. If fine particles such as inorganic substances or organic impurities that do not dissolve in the disk substrate are mixed into the disk substrate constituting the optical disk, the reading characteristics of the information signal recorded on the optical disk are deteriorated. For example, in a compact disk, when fine particles or impurities having a diameter of 50 μm or more are mixed in the disk substrate, the light irradiated to the optical disk for reading information signals by these fine particles or impurities. Birefringence is caused in the beam, and the information signal can not be read accurately.
[0009]
Accordingly, an object of the present invention is to provide a method for producing a colorant for an optical recording medium which is purified with high accuracy without containing fine particles and impurities and does not cause deterioration of optical characteristics such as signal reading characteristics of the optical recording medium. It is to provide.
[0015]
The present invention mixes a dye having a melting point below the decomposition temperature and a plasticizer, melts the mixture of the dye and the plasticizer, filters it through a filter, and then cools to crystallize the dye in the plasticizer . Next, the dye in the plasticizer is diluted by adding the same plasticizer as the plasticizer, and then the particle diameter of the dye is reduced to produce a colorant for an optical recording medium.
[0016]
Here, the filtration of the mixed solution of the dye and the plasticizer is performed using a heating filter of 800 mesh or more.
[0020]
DETAILED DESCRIPTION OF THE INVENTION
The colorant for optical recording media according to the present invention is produced by refining in the molten state using the melting point of the dye constituting the colorant. That is, the dye is melted and impurities that do not melt at the melting temperature of the dye are removed, and filtration using a filter is used to purify the colorant. Furthermore, a heating filter of 800 mesh or more is used for the filter.
[0021]
In the colorant filtered by such a method, the non-molten portion having large particles is removed, so that the non-molten component is prevented from being brought into the synthetic resin material constituting the disk substrate.
[0022]
The colorant containing the dye is filtered by a heating filter of 800 mesh or more, so that the maximum particle of the dye is 50 μm or less.
[0023]
Further, in order to uniformly color a disk substrate formed with a synthetic resin such as a polycarbonate resin with a colorant, it is necessary to uniformly dissolve and disperse the dye in the disk substrate. If the dye is not uniformly dispersed in the disk substrate, color unevenness due to color shading is generated in the optical characteristics of the molded disk substrate. It is considered that the color unevenness due to the interspersed with the dark portion of the color affects not only the size of the dye particles contained in the colorant but also the melting point of the dye. For example, Solpent R, 135, which is a perylene dye, has a melting point of 307 ° C., which is higher than the molding temperature when a polycarbonate resin is molded on a disk substrate. Therefore, it is difficult to dissolve and uniformly dispersed in the disk substrate. appear. When such a dye is used, the dye particle diameter needs to be 30 μm or less.
[0024]
The basic properties of the dye used in the colorant according to the present invention include the following points on the premise that it can withstand the molding processing temperature of, for example, a polycarbonate resin that is a synthetic resin material constituting the disk substrate. Required. That is, the melting point of the dye is not higher than the decomposition temperature of the dye, and there is a difference of at least 10 ° C. between the melting point and the decomposition temperature, and preferably a temperature difference of 15 ° C. or more. The reason for this is that if there is thermal decomposition of the dye during melt filtration, impurities such as burns that are thermally deteriorated during production will cause clogging of the filter used when the dye is melted and filtered, resulting in significant loss of productivity. There are problems such as.
[0025]
In addition, it is desirable to use a dye with less sublimation as the dye used in the colorant of the present invention.
[0026]
As the dye used in the colorant according to the present invention, the following can be used.
[0027]
In anthraquinone system,
Solvent Red 22, 111
Solvent Blue 35, 59, 63
Solvent Green 3
Solvent Violet: 3, 14, 31, 33 can be used.
[0028]
In the methine system,
Solvent Yellow 93, 104
Solvent orange 80 or the like can be used.
[0029]
As the vehicle used in the colorant according to the present invention, a plasticizer is used. Basic properties desirable as a vehicle include suitability as a colorant, that is, safety, dispersion stability of dyes, meterability in pumps, and addition to synthetic resin materials such as polycarbonate resins when molding. Can withstand temperature (approximately 280 ° C to 350 ° C), and does not involve a decrease in molecular weight of synthetic resin materials such as polycarbonate resin, and impact strength, thermal deformation temperature, cracks, bleed of the molded disk substrate It does not adversely affect the mechanical properties such as.
[0030]
For these reasons, it is particularly desirable to use a plasticizer in the vehicle from the viewpoints of easy availability and cost and various physical properties. The vehicle may be one type or two or more types of mixed vehicles.
[0031]
Here, examples of the plasticizer used include phthalate ester plasticizers such as diisodecyl phthalate (DIDP) and tridecyl phthalate (DTDP), epoxidized soybean oil (ESO), and 4,5-epoxycyclohexane-1. 2-dicarboxylic acid di-2-ethylhexyl (E-PS), 4,5-epoxycyclohexane-1,2-diisodecyl (E-PE), glycidyl oleate, 9,10-epoxy allyl stearate, 9,10- Boxy plasticizers such as epoxy stearic acid-2-ethylhexyl, epoxidized tall oil oleate-2-ethylhexyl, bisphenol A glycidyl ether, tributyl phosphate (TBP), trifate phosphate (TPP), toxyl diphenyl phosphate, Phosphate esters such as tripropylene glycol phosphate Plasticizers, fatty acid ester plasticizers such as ptyl stearate (BS), methyl acetylricinoleate (MAR), ethyl acetylricinoleate (EAR), trioctyl trimellitate, trimellitic acid ester, dipentaerythritol ester, pyro Plasticizers such as merit acid ester, poly (propylene glycol, adipic acid) ester, poly (1,3-butanediol, adipic acid) ester, poly (propylene glycol, sebacic acid) ester, poly (1,3-butanediol) , Sebacic acid) ester, poly (propylene glycol, phthalic acid) ester, poly (1,3-butanediol, phthalic acid) ester, poly (ethylene glycol, adipic acid) ester, poly (1,6-hexanediol, adipine Acid) Esters and other polyester types Agents.
[0032]
It is also effective to add an additive to the vehicle for the purpose of facilitating the dispersion of the dye or imparting storage stability.
[0033]
The colorant according to the present invention can be applied to any optical recording medium that optically reads an information signal. For example, the colorant is not limited to a compact disc and is made of a synthetic resin such as a CD-ROM. It is suitable for use in an optical disc having a signal recording portion provided with a reflective film such as aluminum formed on a pit row having minute irregularities on the disc substrate.
[0034]
In the above description, the case where the polycarbonate resin is used as the synthetic resin material constituting the disk substrate has been mainly described. However, the present invention can be similarly applied to the case where the disk substrate is formed of other synthetic resin materials. is there.
[0035]
Next, a specific method for producing the colorant according to the present invention will be described according to procedures (1) to (3).
[0036]
Procedure (1) Purification Method of Dye A liquid dispersion melting method is used for purification of this dye. In order to purify a dye by this liquid melting method, a plasticizer as a vehicle constituting a colorant and a dye are mixed at an arbitrary ratio to prepare a fluid dispersion. Next, the dye is heated to a temperature higher than the melting point of the dye to melt the dye to form a low-viscosity liquid, and this liquid is stored in the storage tank 1 as shown in FIG. At this time, the dye is stored in the storage tank 1 in a liquid state. The liquid dye stored in the storage tank 1 is sucked by the heat pump 2 while being kept in a liquid state and is injected under pressure into the heat filtration filter 3 to remove non-molten matter that is a foreign matter. The filtered material filtered by the filter 3 is supplied to the cooling tank 4 to be cooled, and is taken out in a dispersed state in which dye crystal particles are precipitated and grown in the vehicle.
[0037]
A direct melting method can also be used for the purification of the dye. In order to purify the dye by this direct melting method, the dye is ripened above the melting temperature and melted, and the molten dye is filtered by applying pressure to the filter using a heating pump, and then cooled to form a solid mass. The purified dye is taken out and a pulverization step is obtained, and then dispersed in a vehicle to obtain a colorant.
[0038]
Here, it is desirable to purify using the liquid dispersion melting method.
[0039]
Procedure (2) Coloration of dye particles (miniaturization and dispersion)
After the dye purified by the above-mentioned liquid dispersion melting method is diluted and mixed in a plasticizer as a vehicle at an arbitrary ratio (weight ratio), the dye particles are dispersed into the plasticizer using a three-roll roll while making the particles fine. . The degree of miniaturization of the dye particles is determined by adjusting the number of passes of the three rolls and the clearance. The measurement of the particle diameter of the dye dispersed in the plasticizer is obtained according to the IIS standard (K5400, 4-4 method) to obtain a liquid colorant controlled to an arbitrary particle diameter. The maximum particle size of the obtained dye is adjusted to 50 μm or less.
[0040]
Procedure (3) Coloring Method The liquid colorant obtained by the above-described procedure is mixed into a raw material resin, for example, a polycarbonate resin, which is put into a hopper attached to the upper part of an injection molding machine for molding a disk substrate. The mixing of the colorant is performed by injecting a specified amount from the nozzle using a pump.
[0041]
The polycarbonate resin mixed with this colorant is melted by a heating and melting part provided in an injection molding machine, and is injected into a mold part from an injection nozzle provided at the tip of the heating and melting part, thereby forming a disk substrate. The The disk substrate is transferred with a pit row composed of minute irregularities provided in a stamper provided in the mold part.
[0042]
Here, a reflective film is formed on the side of the molded disk substrate on which the pit rows are formed, and further, a protective film is formed to cover the reflective film to form an optical disk as an optical recording medium.
[0043]
【Example】
Next, specific examples of the colorant according to the present invention are shown.
[0044]
Various dyes purified by the above-described procedure (1) are blended in the plasticizer in the following ratio.
[0045]
Formulation Example 1
Solvent Violet 33 100 parts by weight Polyester plasticizer 300 parts by weight (Mitsubishi Chemical Diasizer D623)
Formulation Example 2
Sovennt Red 22 100 parts by weight polyester plasticizer (same as above) 200 parts by weight Formulation Example 3
Solvent Yellow 93 100 parts by weight Polyester plasticizer <Same as above> 400 parts by weight The dye blended in the plasticizer at such a blending ratio is mixed with the plasticizer to form a dispersion. Next, the mixed liquid in which the dye is dispersed and mixed in the plasticizer is heated under a temperature condition equal to or higher than the melting point of each dye, and stored as a liquid in the storage tank 1 shown in FIG.
[0046]
Here, since Solvent Violet 33 used in Formulation Example 1 has a melting point of 143 ° C., the one in Formulation Example 1 is melted and liquefied at a higher temperature of 170 ° C.
[0047]
Moreover, since So1vent Red 22 used for the compounding example 2 has a melting point of 138 ° C., the compound of the compounding example 2 is melted and liquefied at a higher temperature of 150 ° C.
[0048]
Furthermore, since So1vennt Red 22 used in Formulation Example 3 has a melting point of 182 ° C., Formulation Example 3 is melted and liquefied at a higher temperature of 230 ° C.
[0049]
The liquefied dyes of Formulation Examples 1 to 3 that have been liquefied and stored in the storage tank 1 are sucked by the heat pump 2, pressurized and injected into the heat filtration filter 3, and filtered. Here, a filter with 800 mesh attached is used as the heat filtration filter 3 (TSC type manufactured by Advantech Toyo Co., Ltd.). The dye as the filtrate filtered by the heating filter 3 is supplied to the cooling tank 4 and cooled at room temperature to obtain dye crystal particles dispersed in the plasticizer.
[0050]
The purified dyes of Formulation Examples 1 to 3, which have been purified as described above, are each diluted and mixed with the same type of plasticizer as the plasticizer described above.
[0051]
Here, the purified dye of Formulation Example 1 is diluted by mixing 150 parts by weight of a plasticizer with respect to 100 parts by weight of the purified dye. Similarly, the purified dye of Formulation Example 2 is diluted by mixing 200 parts by weight of a plasticizer with respect to 100 parts by weight of the purified dye. Further, the dye of Formulation Example 3 is diluted by mixing 100 parts by weight of a plasticizer with 100 parts by weight of the purified dye. As described above, the dye diluted with these plasticizers is refined and dispersed. The fineness and dispersion of the dye are made into a paste-like colorant having a maximum particle size of 50 μm or less by a grind gauge while adjusting the number of times and clearance with three rolls.
[0052]
The colorants obtained from Formulation Examples 1, 2, and 3 are Colorant (1), Colorant (2), and Colorant (3), respectively. Next, the polycarbonate resin that is added to the injection molding machine by mixing these colorants (1), (2), and (3) singly or in a mixture of two or more kinds so as to change the mixing ratio as appropriate. The polycarbonate mixed with the colorant is melted and injected into an injection molding machine to form a disk substrate.
[0053]
The disk substrate formed here is colored blue, red, pio red, yellow, etc., in combination with colorants (1), (2), (3) mixed with polycarbonate resin. It becomes. The disc substrate obtained here sufficiently satisfies the optical characteristics as those constituting the optical disc.
[0054]
Here, Table 1 shows the amounts of the coloring agents (1), (2), and (3) added to the polycarbonate resin for coloring the disk substrate in an arbitrary color. Here, the addition amount with respect to the polycarbonate resin of a coloring agent is shown by weight%. Furthermore, it is shown whether or not the optical characteristics of the disk substrate obtained here are sufficient for use in an optical disk. Here, the quality of the optical characteristics was determined to be good if 95% or more of the manufactured disk substrate shows sufficient optical characteristics to be used for the optical disk.
[0055]
[Table 1]

[0056]
As an evaluation corresponding to the corresponding Examples 1 to 4 shown in Table 1, an unpurified dye obtained by using a dye that has not been purified as described above, mixing this dye with a plasticizer, and performing finer and dispersed dispersion. Colorants (1), (2), and (3) were prepared and mixed with polycarbonate resin to form a disk substrate for comparison. The results are shown in Table 2.
[0057]
[Table 2]

[0058]
As is apparent from this result, a disc substrate produced using an unpurified colorant could not obtain sufficient optical characteristics for use in an optical disc.
[0059]
【The invention's effect】
As described above, by using the present invention, it is possible to obtain an optical recording medium that uniformly colors the entire medium and that does not cause deterioration of optical characteristics such as signal reading characteristics.
[Brief description of the drawings]
FIG. 1 shows an apparatus for purifying a colorant according to the present invention.
[Explanation of symbols]
1 storage tank, 2 heating pump, 3 heating filter, 4 cooling tank.

Claims (3)

Mix the dye and plasticizer whose melting point is below the decomposition temperature,
The mixture of the dye and the plasticizer is melted and filtered through a filter, and then cooled to crystallize the dye in the plasticizer .
Then, the dye in the plasticizer, diluted by the addition of the plasticizer and the same type of plasticizer, the production method of the coloring agent for an optical recording medium comprising performing finer particle diameter of the dye.   The method for producing a colorant for an optical recording medium according to claim 1, wherein the filtration of the mixture of the dye and the plasticizer is performed using a heating filter of 800 mesh or more.   The method for producing a colorant for an optical recording medium according to claim 1, wherein the dye has a difference between the melting point and the decomposition temperature of 10 ° C. or more.

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