JP2007131010A - Manufacturing process of optical disk - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a manufacturing process of a high-quality optical disk with low carbonized matter generation. <P>SOLUTION: The manufacturing process of the optical disk is characterized by the followings. The process uses a substrate which is molded by injection molding of a pellet. (i) The pellet is obtained by melt extruding an aromatic polycarbonate resin with a viscosity average molecular weight of 13,000-18,000 into a strand, and cutting it after cooling with warm water. (ii) The pellet generates 250 ppm or less fine powder with a particle size of 1.0 mm or less after the following steps: 5 kg of the pellet is weighed, packed into two-ply polyethylene bags of 500 mm width, 864 mm length and 0.08 mm thickness, and compressed air is blown to inflate the bag (ca. 38 L inner volume), then the pellet-containing bag is put into a blender and shaken for 60 minutes by revolving the blender at 25 r.p.m. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to an optical disc manufacturing method. More specifically, the present invention relates to a method for producing an optical disk using aromatic polycarbonate resin pellets that are extremely small in the generation of fine powder during transportation, transportation, and storage and that are suitable for optical molding materials.

Aromatic polycarbonate resins (hereinafter sometimes simply referred to as “PC resins”) have high transparency and are excellent in heat resistance and dimensional stability, and are therefore used as optical recording materials such as optical disc materials. A typical example of an optical disk using PC resin is a compact disk (CD). Recently, a DVD, DVD-ROM or DVD-RAM having a further improved recording capacity, particularly recording density, has been developed. It is being advanced.
The PC resin used for these optical discs is required to have high quality. As one of them, it is known that a small content of the resin fine powder in the PC resin pellet affects the characteristics and quality of the molded product. It is known that when a certain amount or more of resin fine powder is present in the PC resin pellet to be molded, the optical disk molded therefrom has various defects as a recording material due to generation of carbides and the like. For example, Patent Document 1 discloses that the content of a powdery polymer having an average particle size of 0.5 mm or less in a PC resin pellet should be 2.0% by weight or less.

Conventionally, the amount of fine powder contained in the PC resin is measured by a method such as sieving the produced pellet as it is or washing with water. However, when considering from the standpoint of the PC resin producer or supplier, this method cannot grasp the amount of fine powder generated in the transportation of PC resin pellets and pipes, and the above process actually used for molding It is not possible to grasp the amount of fine powder of the pellets that have undergone the process. Therefore, the relationship between the amount of fine powder and the amount of carbide generated in the optical disk is not clear.
Japanese Patent Publication No. 6-18890

An object of the present invention is to clarify the relationship between the amount of fine powder and the amount of generated carbide by grasping the amount of fine powder contained in the resin pellets actually used for molding. Another object of the present invention is to provide a method for producing a high-quality optical disc with a small amount of carbide generated using resin pellets with a small amount of fine powder (amount of fine powder generated) generated by transportation and transportation.
As a result of investigating the present inventors to achieve the above-mentioned problems, the amount of fine powder contained in the pellets after transportation and transportation is controlled by shaking the resin pellets for a certain period of time and controlling the amount of fine powder generated as a result. I found that I can estimate. Further, it has been found that resin pellets with less generation of fine powder can be produced by improving the cooling method and temperature of the resin pellets.

The present invention has been achieved on the basis of the above knowledge, and is a method for producing an optical disc using a substrate by molding a substrate by injection molding a pellet,
(I) The pellet is a pellet obtained by melt-extruding an aromatic polycarbonate resin having a viscosity average molecular weight of 13,000 to 18,000 into a strand, cooling with warm water and then cutting, and (ii) The pellets weighed 5 kg of the pellets, packed in a stack of two polyethylene bags having a width of 500 mm, a length of 864 mm, and a thickness of 0.08 mm, blown inflated with compressed air (with an internal volume of about 38 L), and then the pellets Put a polyethylene bag with a blender into the blender, and 25r. p. m. The amount of fine powder having a particle size of 1.0 mm or less after rotating the blender for 60 minutes and shaking is 250 ppm or less.
An optical disc manufacturing method characterized by the above.

The pellet preferably has an amount of fine powder having a particle size of 1.0 mm or less of 150 ppm or less.
The pellet preferably has a diameter of 2.0 to 3.3 mm and a length of 2.5 to 3.5 mm.
The pellet is preferably a pellet obtained by cutting the melt-extruded strand in a cooling tank filled with warm water and then cooling.
The pellet is preferably a pellet obtained by cutting a strand at such a temperature that the pellet temperature immediately after cutting the strand becomes 110 to 130 ° C.
The aromatic polycarbonate resin is preferably a polycarbonate resin obtained using bisphenol A as a dihydric phenol.
The optical disk is preferably a CD, DVD, DVD-ROM or DVD-RAM.
The amount of fine powder generated in the pellet is extremely small due to its transportation and delivery, and the resin pellet producer or supplier can control the amount of fine resin powder when the resin pellet is used (molded). As a result, it is possible to manufacture an optical disc with excellent quality.

  The pellets used in the present invention can suppress the generation of carbides due to molding. The PC resin pellets used in the present invention generate a very small amount of fine powder with respect to shaking by transportation and delivery, and the PC resin pellets can be molded to produce a high-quality optical disc with a small amount of carbide generation. .

  The present invention will be described in more detail below.

  The aromatic polycarbonate resin in the present invention is usually obtained by reacting a dihydric phenol and a carbonate precursor by a solution method or a melting method. Representative examples of the dihydric phenol used here include hydroquinone, resorcinol, 4,4′-dihydroxydiphenyl, bis (4-hydroxyphenyl) methane, bis {(4-hydroxy-3,5-dimethyl). Phenyl} methane, 1,1-bis (4-hydroxyphenyl) ethane, 1,1-bis (4-hydroxyphenyl) -1-phenylethane, 2,2-bis (4-hydroxyphenyl) propane (commonly referred to as bisphenol A) ), 2,2-bis {(4-hydroxy-3-methyl) phenyl} propane, 2,2-bis {(4-hydroxy-3,5-dimethyl) phenyl} propane, 2,2-bis {(3 , 5-Dibromo-4-hydroxy) phenyl} propane, 2,2-bis {(3-isopropyl-4-hydroxy) phenyl} propane 2,2-bis {(4-hydroxy-3-phenyl) phenyl} propane, 2,2-bis (4-hydroxyphenyl) butane, 2,2-bis (4-hydroxyphenyl) -3-methylbutane, 2, 2-bis (4-hydroxyphenyl) -3,3-dimethylbutane, 2,4-bis (4-hydroxyphenyl) -2-methylbutane, 2,2-bis (4-hydroxyphenyl) pentane, 2,2- Bis (4-hydroxyphenyl) -4-methylpentane, 1,1-bis (4-hydroxyphenyl) cyclohexane, 1,1-bis (4-hydroxyphenyl) -4-isopropylcyclohexane, 1,1-bis (4 -Hydroxyphenyl) -3,3,5-trimethylcyclohexane, 9,9-bis (4-hydroxyphenyl) fluorene, 9,9-bi {(4-hydroxy-3-methyl) phenyl} fluorene, α, α′-bis (4-hydroxyphenyl) -o-diisopropylbenzene, α, α′-bis (4-hydroxyphenyl) -m-diisopropylbenzene, α, α′-bis (4-hydroxyphenyl) -p-diisopropylbenzene, 1,3-bis (4-hydroxyphenyl) -5,7-dimethyladamantane, 4,4′-dihydroxydiphenylsulfone, 4,4 ′ -Dihydroxydiphenyl sulfoxide, 4,4'-dihydroxydiphenyl sulfide, 4,4'-dihydroxydiphenyl ketone, 4,4'-dihydroxydiphenyl ether, 4,4'-dihydroxydiphenyl ester, and the like. The above can be mixed and used.

  Among them, bisphenol A, 2,2-bis {(4-hydroxy-3-methyl) phenyl} propane, 2,2-bis (4-hydroxyphenyl) butane, 2,2-bis (4-hydroxyphenyl) -3 -Methylbutane, 2,2-bis (4-hydroxyphenyl) -3,3-dimethylbutane, 2,2-bis (4-hydroxyphenyl) -4-methylpentane, 1,1-bis (4-hydroxyphenyl) A homopolymer or copolymer obtained from at least one bisphenol selected from the group consisting of 3,3,5-trimethylcyclohexane and α, α′-bis (4-hydroxyphenyl) -m-diisopropylbenzene In particular, a homopolymer of bisphenol A and 1,1-bis (4-hydroxyphenyl) -3,3,5-trimethyl Copolymers of rucyclohexane and bisphenol A, 2,2-bis {(4-hydroxy-3-methyl) phenyl} propane or α, α'-bis (4-hydroxyphenyl) -m-diisopropylbenzene are preferably used. Is done.

As the carbonate precursor, carbonyl halide, carbonate ester, haloformate or the like is used, and specific examples include phosgene, diphenyl carbonate, dihaloformate of dihydric phenol, and the like.
When producing the aromatic polycarbonate resin by reacting the above dihydric phenol and carbonate precursor by a solution method or a melting method, a catalyst, a terminal terminator, a dihydric phenol antioxidant, etc. are used as necessary. May be. The aromatic polycarbonate resin may be a branched polycarbonate resin copolymerized with a trifunctional or higher polyfunctional aromatic compound, or a polyester carbonate resin copolymerized with an aromatic or aliphatic difunctional carboxylic acid. Moreover, the mixture which mixed 2 or more types of the obtained aromatic polycarbonate resin may be sufficient.

  The reaction by the solution method is usually a reaction between a dihydric phenol and phosgene, and is reacted in the presence of an acid binder and an organic solvent. As the acid binder, for example, an alkali metal hydroxide such as sodium hydroxide or potassium hydroxide or an amine compound such as pyridine is used. As the organic solvent, for example, halogenated hydrocarbons such as methylene chloride and chlorobenzene are used. In order to accelerate the reaction, a catalyst such as a tertiary amine such as triethylamine, tetra-n-butylammonium bromide or tetra-n-butylphosphonium bromide, a quaternary ammonium compound or a quaternary phosphonium compound may be used. it can. At that time, the reaction temperature is usually 0 to 40 ° C., the reaction time is preferably about 10 minutes to 5 hours, and the pH during the reaction is preferably maintained at 9 or more.

  In such a polymerization reaction, a terminal stopper is usually used. Monofunctional phenols can be used as such end terminators. Monofunctional phenols are commonly used as end terminators for molecular weight control, and the resulting polycarbonate resins are compared to those that do not because the ends are blocked by groups based on monofunctional phenols. Excellent thermal stability. Such monofunctional phenols are generally phenol or lower alkyl-substituted phenols, and monofunctional phenols represented by the following general formula (1) can be shown.

[Wherein, A is a hydrogen atom, a linear or branched alkyl group having 1 to 9 carbon atoms or a phenyl-substituted alkyl group, and r is an integer of 1 to 5, preferably 1 to 3].
Specific examples of the monofunctional phenols include phenol, p-tert-butylphenol, p-cumylphenol and isooctylphenol.

  Further, as other monofunctional phenols, phenols or benzoic acid chlorides having a long chain alkyl group or an aliphatic polyester group as a substituent, or long chain alkyl carboxylic acid chlorides can be used, When these are used to block the ends of the polycarbonate copolymer, they not only function as end terminators or molecular weight regulators, but also improve the melt fluidity of the resin, facilitating the molding process, It has the effect of lowering the physical properties, particularly the water absorption rate of the resin, and also has the effect of reducing the birefringence of the substrate, which is preferably used. In particular, it has the effect of reducing the water absorption rate of the resin and is preferably used. Of these, phenols having a long-chain alkyl group represented by the following general formulas (2) and (3) as a substituent are preferably used.

[Wherein, X is —R—O—, —R—CO—O— or —R—O—CO—, wherein R is a single bond or a carbon number of 1 to 10, preferably 1 to 5; A valent aliphatic hydrocarbon group, and n represents an integer of 10 to 50. ]
As the substituted phenols of the general formula (2), those having n of 10 to 30, particularly 10 to 26 are preferable, and specific examples thereof include decylphenol, dodecylphenol, tetradecylphenol, hexadecylphenol, octadecylphenol, Examples include eicosylphenol, docosylphenol, and triacontylphenol.

Further, as the substituted phenols of the general formula (3), those in which X is —R—CO—O— and R is a single bond are suitable, and those in which n is 10 to 30, particularly 10 to 26. Specific examples thereof include decyl hydroxybenzoate, dodecyl hydroxybenzoate, tetradecyl hydroxybenzoate, hexadecyl hydroxybenzoate, eicosyl hydroxybenzoate, docosyl hydroxybenzoate and triacontyl hydroxybenzoate.
These end terminators are desirably introduced at the end of at least 5 mol%, preferably at least 10 mol% with respect to all the ends of the obtained polycarbonate resin, and the end terminators may be used alone or in combination of two or more. You may mix and use.

  The reaction by the melting method is usually a transesterification reaction between a dihydric phenol and a carbonate ester. In the presence of an inert gas, the dihydric phenol and the carbonate ester are mixed while being heated, and the resulting alcohol or phenol is distilled. It is done by the method of making it come out. The reaction temperature varies depending on the boiling point of the alcohol or phenol produced, but is usually in the range of 120 to 350 ° C. In the latter stage of the reaction, the system is evacuated to about 10 to 0.1 Torr to facilitate the distillation of the alcohol or phenol produced. The reaction time is usually about 1 to 4 hours.

  Examples of the carbonate ester include esters such as an optionally substituted aryl group having 6 to 10 carbon atoms, an aralkyl group, or an alkyl group having 1 to 4 carbon atoms. Specific examples include diphenyl carbonate, ditolyl carbonate, bis (chlorophenyl) carbonate, m-cresyl carbonate, dinaphthyl carbonate, bis (diphenyl) carbonate, dimethyl carbonate, diethyl carbonate, and dibutyl carbonate. Is particularly preferred.

A polymerization catalyst can be used to increase the polymerization rate. Examples of such polymerization catalyst include sodium hydroxide, potassium hydroxide, sodium salt of dihydric phenol, alkali metal compounds such as potassium salt, calcium hydroxide, Alkaline earth metal compounds such as barium hydroxide and magnesium hydroxide, nitrogen-containing basic compounds such as tetramethylammonium hydroxide, tetraethylammonium hydroxide, trimethylamine and triethylamine, alkoxides of alkali metals and alkaline earth metals, alkali metals And organic earth salts of alkaline earth metals, zinc compounds, boron compounds, aluminum compounds, silicon compounds, germanium compounds, organotin compounds, lead compounds, osmium compounds, antimony compounds manganese compounds, H Emission compounds, usually the esterification reaction, such as zirconium compounds, there can be used a catalyst used in the transesterification reaction. A catalyst may be used independently and may be used in combination of 2 or more types. The amount of these polymerization catalysts used is preferably 1 × 10 ⁻⁸ to 1 × 10 ⁻³ equivalent, more preferably 1 × 10 ^{−7 to} 5 × 10 ⁻⁴ equivalent, relative to 1 mol of dihydric phenol as a raw material. Selected by range.

  In the polymerization reaction, in order to reduce phenolic end groups, for example, bis (chlorophenyl) carbonate, bis (bromophenyl) carbonate, bis (nitrophenyl) carbonate, bis ( It is preferable to add compounds such as (phenylphenyl) carbonate, chlorophenylphenyl carbonate, bromophenylphenyl carbonate, nitrophenylphenyl carbonate, phenylphenyl carbonate, methoxycarbonylphenylphenyl carbonate and ethoxycarbonylphenylphenyl carbonate. Of these, 2-chlorophenyl phenyl carbonate, 2-methoxycarbonylphenyl phenyl carbonate and 2-ethoxycarbonylphenyl phenyl carbonate are preferable, and 2-methoxycarbonylphenyl phenyl carbonate is particularly preferably used.

The molecular weight of the aromatic polycarbonate resin is 13,000 to 18,000 in terms of viscosity average molecular weight (M). A polycarbonate resin having such a viscosity average molecular weight is preferable because it provides sufficient strength as an optical material and has good melt fluidity during molding and does not cause molding distortion. The viscosity average molecular weight referred to in the present invention is obtained by inserting the specific viscosity (η _sp ) obtained from a solution obtained by dissolving 0.7 g of a polycarbonate resin in 100 mL of methylene chloride at 20 ° C. into the following equation.
η _sp /c=[η]+0.45×[η] ² c (where [η] is the intrinsic viscosity)
[Η] = 1.23 × 10 ⁻⁴ M ^0.83
c = 0.7

  In the present invention, the amount of fine powder of PC resin pellets is measured by the following method. After weighing 5 kg of the PC resin pellets, they are packed in a stack of two polyethylene bags having a width of 500 mm, a length of 864 mm, and a thickness of 0.08 mm, and inflated with compressed air (internal capacity of about 38 L). Next, the polyethylene bag containing the pellets was placed in a blender (Tanaka Iron Works, Model 50), and 25r. p. m. Shake for 60 minutes by rotating the blender. Thereafter, the pellet is passed through a circular vibrating sieve (manufactured by Tokuju Kogyo Co., Ltd., TM-70-2S) to separate a fine powder of 1.0 mm or less. At this time, since the fine powder adheres to the polyethylene bag containing the pellets, the polyethylene bag is washed with water, and the washing water is filtered through a circular filter paper and dried at 60 ° C. for 24 hours to collect the fine powder. The total of these two types of fine powder is defined as fine powder (A). Next, 5 kg of unblendered pellets are put on a circular vibrating sieve to separate fine powder of 1.0 mm or less. Let this fine powder amount be a fine powder (B). The value obtained by subtracting the fine powder (B) from the fine powder (A) is the amount of fine powder generated, and is considered to be the amount of fine powder generated during transportation and piping transportation. By reducing this, the fine powder (A) And the generation of carbides during molding can be suppressed.

  In the present invention, the shape of the PC resin pellet is not particularly limited as long as it is used as a PC resin pellet for molding, particularly as a PC resin pellet for optical molding materials. In general, a material having a diameter of 2.0 to 3.3 mm and a length of 2.5 to 3.5 mm is suitable. When the PC resin pellet of the present invention is shaken and mixed, the amount of fine powder generated is extremely small. Therefore, when extruding resin with an extruder to make a strand and cutting this with a cutter to obtain a pellet, it is desirable that the cross-sectional shape of the pellet is circular and has few irregularities. In order to reduce the unevenness of the cross-sectional shape, it is desirable that the strands are cooled as uniformly as possible around the strands. At that time, it is desirable to cool the pellet so that the pellet temperature immediately after cutting the strand is preferably 110 to 130 ° C, more preferably 120 to 130 ° C. Thus, twist of the strand can be reduced and surface irregularities can be reduced.

  The aromatic polycarbonate resin obtained in the present invention is used as an optical molding material, for example, an optical disk substrate material, with very little generation of fine powder during transportation, transportation and storage. Specific examples of the optical disk include CD, CD-ROM, CD-R, MO, PD, DVD, DVD-ROM, DVD-R, and DVD-RAM.

  Hereinafter, the present invention will be described with reference to examples and comparative examples.

Example 1
Into a reactor equipped with a thermometer, a stirrer and a reflux condenser, 219.4 parts of ion-exchanged water and 40.2 parts of 48% sodium hydroxide aqueous solution were blown, and 2,2-bis (4-hydroxyphenyl) propane 57. After 5 parts (0.252 mol) and 0.12 part of hydrosulfite were dissolved, 181 parts of methylene chloride was added, and 28.3 parts of phosgene was blown in at 15 to 25 ° C. with stirring for 40 minutes. After completion of the phosgene blowing, 7.2 parts of 48% aqueous sodium hydroxide and 2.42 parts of p-tert-butylphenol were added, stirring was started, and after emulsification, 0.06 part of triethylamine was added, and further at 28 to 33 ° C. for 1 hour. The reaction was terminated by stirring. After completion of the reaction, the product is diluted with methylene chloride, washed with water, acidified with hydrochloric acid, washed with water, and when the water phase conductivity is almost the same as ion-exchanged water, an isolation chamber with a foreign matter outlet is provided at the bearing. Then, methylene chloride was evaporated by a kneader to obtain a powder having a viscosity average molecular weight of 15000. To this powder, 0.01% by weight of tris (2,4-di-tert-butylphenyl) phosphite and 0.08% by weight of stearic acid monoglyceride were added. Strands of this powder were extruded with a 30 mm extruder in the temperature range of 250 to 270 ° C., pelletized with a cutter, and the amount of fine powder (A) was measured by the method described above. At this time, as a cooling method, in order to reduce unevenness of the cross-sectional shape of the pellet, a method of cooling the strand by attaching it to a cooling tank filled with warm water (bath cooling method) was used. The pellet temperature immediately after cutting with a cutter was 130 ° C. Next, this pellet was molded into an Al-attached substrate having a thickness of 1.2 mm and 120 mmφ using an injection molding machine (DISK3MIII manufactured by Sumitomo Heavy Industries, Ltd.), and the BLER of this substrate was measured using a BLER measuring machine (Sony CDplayer Control Unit CDS 3000). The results are shown in Table 1. The C ₁ AVE shown here is an average value per second of C1 errors (random errors that can be corrected by the C1 code).

Example 2
The same operation as in Example 1 was carried out except that the pellet temperature immediately after cutting with a cutter in Example 1 was 120 ° C. The results are shown in Table 1.

Example 3
The same operation as in Example 1 was performed except that the pellet temperature immediately after cutting with a cutter in Example 1 was changed to 110 ° C. The results are shown in Table 1.

Comparative Example 1
In Example 1, the same operation as in Example 1 was carried out except that a method of cooling the strand through a corrugated sheet in which cooling water was passed (corrugated sheet cooling method) was used as a cooling method. The results are shown in Table 1.

Comparative Example 2
The same operation as in Comparative Example 1 was performed except that the pellet temperature immediately after cutting with a cutter in Comparative Example 1 was changed to 110 ° C. The results are shown in Table 1.

Example 4
In Example 1, the substances to be added to the powder having a viscosity average molecular weight of 15,000 were trimethyl phosphate 0.007% by weight, tris (2,4-di-tert-butylphenyl) phosphite 0.003% by weight, pentaerythritol tetrastearate. The same operation as in Example 1 was performed except that the rate was 0.06% by weight. The results are shown in Table 1.

Example 5
The same operation as in Example 4 was performed except that the pellet temperature immediately after cutting with a cutter in Example 4 was 120 ° C. The results are shown in Table 1.

Example 6
The same operation as in Example 4 was performed except that the pellet temperature immediately after cutting with a cutter in Example 4 was changed to 110 ° C. The results are shown in Table 1.

Comparative Example 3
In Comparative Example 1, the substances to be added to the powder having a viscosity average molecular weight of 15,000 were trimethyl phosphate 0.007% by weight, tris (2,4-di-tert-butylphenyl) phosphite 0.003% by weight, pentaerythritol tetrastearate. The same operation as in Comparative Example 1 was carried out except that the rate was 0.06% by weight. The results are shown in Table 1.

Comparative Example 4
The same operation as in Comparative Example 3 was carried out except that the pellet temperature immediately after cutting with a cutter in Comparative Example 3 was 110 ° C. The results are shown in Table 1.

Example 7
In Example 1, the substance added to the powder having a viscosity average molecular weight of 15,000 was changed to 0.007% by weight of trisnonylphenyl phosphate, 0.003% by weight of trimethyl phosphate, and 0.08% by weight of pentaerythritol tetrastearate. Carried out the same operation as in Example 1. The results are shown in Table 1.

Example 8
The same operation as in Example 7 was performed except that the pellet temperature immediately after cutting with a cutter in Example 7 was 120 ° C. The results are shown in Table 1.

Example 9
The same operation as in Example 7 was performed except that the pellet temperature immediately after cutting with a cutter in Example 7 was changed to 110 ° C. The results are shown in Table 1.

Comparative Example 5
In Comparative Example 1, the substance added to the powder having a viscosity average molecular weight of 15,000 was 0.007% by weight of trisnonylphenyl phosphite, 0.003% by weight of trimethyl phosphate, and 0.08% by weight of pentaerythritol tetrastearate. Carried out the same operation as in Comparative Example 1. The results are shown in Table 1.

Comparative Example 6
In Comparative Example 5, the same operation as in Comparative Example 5 was carried out except that the pellet temperature immediately after cutting with a cutter was 110 ° C. The results are shown in Table 1.

Example 10
In Example 1, the substance added to the powder having a viscosity average molecular weight of 15,000 was changed to 0.003 wt% trisnonylphenyl phosphite, 0.005 wt% trimethyl phosphate, and 0.045 wt% stearic acid monoglyceride. The same operation as 1 was performed. The results are shown in Table 1.

Example 11
The same operation as in Example 10 was performed except that the pellet temperature immediately after cutting with a cutter in Example 10 was 120 ° C. The results are shown in Table 1.

Example 12
The same operation as in Example 10 was performed except that the pellet temperature immediately after cutting with a cutter in Example 10 was 110 ° C. The results are shown in Table 1.

Comparative Example 7
Comparative Example 1 except that the substance added to the powder having a viscosity average molecular weight of 15,000 in Comparative Example 1 was 0.003% by weight of trisnonylphenyl phosphite, 0.005% by weight of trimethyl phosphate, and 0.045% by weight of stearic acid monoglyceride. The same operation as 1 was performed. The results are shown in Table 1.

Comparative Example 8
The same operation as in Comparative Example 7 was performed except that the pellet temperature immediately after cutting with a cutter in Comparative Example 7 was 110 ° C. The results are shown in Table 1.

Example 13
In Example 1, the substances to be added to the powder having a viscosity average molecular weight of 15,000 were 0.0015% by weight of phosphorous acid, 0.01% by weight of tris (2,4-di-tert-butylphenyl) phosphite, monoglyceride stearate The same operation as in Example 1 was performed except that the content was changed to 0.08% by weight. The results are shown in Table 1.

Example 14
The same operation as in Example 13 was performed except that the pellet temperature immediately after cutting with a cutter in Example 13 was 120 ° C. The results are shown in Table 1.

Example 15
The same operation as in Example 13 was performed except that the pellet temperature immediately after cutting with a cutter in Example 13 was 110 ° C. The results are shown in Table 1.

Comparative Example 9
In Comparative Example 1, the substances to be added to the powder having a viscosity average molecular weight of 15,000 were 0.0015% by weight of phosphorous acid, 0.01% by weight of tris (2,4-di-tert-butylphenyl) phosphite, monoglyceride stearate The same operation as in Comparative Example 1 was performed except that the content was changed to 0.08% by weight. The results are shown in Table 1.

Comparative Example 10
The same operation as in Comparative Example 9 was performed except that the pellet temperature immediately after cutting with a cutter in Comparative Example 9 was 110 ° C. The results are shown in Table 1.

Example 16
In Example 1, the substances added to the powder having a viscosity average molecular weight of 15,000 were 0.01% by weight of 4,4′-biphenylenediphosphinic acid (2,4-di-tert-butylphenyl) and 0.08% by weight of stearic acid monoglyceride. The same operation as in Example 1 was carried out except that the percentage was changed to%. The results are shown in Table 1.

Example 17
The same operation as in Example 16 was performed except that the pellet temperature immediately after cutting with a cutter in Example 16 was 120 ° C. The results are shown in Table 1.

Example 18
The same operation as in Example 16 was performed except that the pellet temperature immediately after cutting with a cutter in Example 16 was 110 ° C. The results are shown in Table 1.

Comparative Example 11
In Comparative Example 1, the substances added to the powder having a viscosity average molecular weight of 15,000 were 0.01% by weight of 4,4′-biphenylenediphosphinic acid (2,4-di-tert-butylphenyl) and 0.08% by weight of stearic acid monoglyceride. The same operation as in Comparative Example 1 was carried out except that the percentage was changed to%. The results are shown in Table 1.

Comparative Example 12
In Comparative Example 11, the same operation as in Example 11 was performed except that the pellet temperature immediately after cutting with a cutter was changed to 110 ° C. The results are shown in Table 1.

Example 19
In a reactor equipped with a stirrer and a distillation column, 228 parts (about 1 mol) of 2,2-bis (4-hydroxyphenyl) propane (bisphenol A), 220 parts of diphenyl carbonate (manufactured by Bayer) (about 1.03 mol) ) And 0.000024 parts of sodium hydroxide (about 6 × 10 ⁻⁷ mol / mol of bisphenol A) and 0.0073 parts of tetramethylammonium hydroxide (about 8 × 10 ⁻⁵ mol / mol of bisphenol A) as a catalyst, Replaced with nitrogen. This mixture was heated to 200 ° C. and dissolved with stirring. Next, most of the phenol was distilled off in one and a half hours while heating at a reduced pressure of 30 Torr. The temperature was further raised to 270 ° C. and the polymerization reaction was carried out at a reduced pressure of 1 Torr. 2.3 parts of phenyl carbonate were added. Thereafter, end-capping reaction was carried out at 270 ° C. and 1 Torr or less for 5 minutes. Next, in the molten state, 0.00023 part of dodecylbenzenesulfonic acid tetrabutylphosphonium salt is added as a catalyst neutralizing agent, and the reaction is further continued at 270 ° C. and 10 Torr or less for 10 minutes to obtain a polymer having a viscosity average molecular weight of 15,000. Got. This polymer was sent to a 30 mm extruder by a gear pump. In the middle of the extruder, 0.01% by weight of tris (2,4-di-tert-butylphenyl) phosphite and 0.08% by weight of stearic acid monoglyceride were added, and a 30 mm extruder was used at a temperature range of 250 ° C to 270 ° C. The strand was extruded, pelletized with a cutter, and the fine powder amount (A) was measured by the method described above. At this time, in order to reduce unevenness in the cross-sectional shape of the pellet, a method of cooling the strand by attaching it to a cooling tank filled with warm water was used. The pellet temperature immediately after cutting with a cutter was 130 ° C. Using this pellet, a substrate was molded and evaluated in the same manner as in Example 1. The results are shown in Table 2.

Examples 20 and 21
In Example 19, the same operation as in Example 19 was performed except that the pellet temperature immediately after cutting the strand with a cutter was 120 ° C. (Example 20) or 110 ° C. (Example 21). The results are shown in Table 2.

Example 22
In Example 19, the substances added to the polymer having a viscosity average molecular weight of 15,000 were trimethyl phosphate 0.007% by weight, tris (2,4-di-tert-butylphenyl) phosphite 0.003% by weight, pentaerythritol tetrastearate. The same operation as in Example 19 was performed except that the rate was 0.06% by weight. The results are shown in Table 2.

Examples 23 and 24
In Example 22, the same operation as in Example 22 was performed except that the pellet temperature immediately after cutting the strand with a cutter was 120 ° C. (Example 23) or 110 ° C. (Example 24). The results are shown in Table 2.

Example 25
In Example 19, the substance added to the polymer having a viscosity average molecular weight of 15,000 was changed to 0.007% by weight of trisnonylphenyl phosphite, 0.003% by weight of trimethyl phosphate, and 0.08% by weight of pentaerythritol tetrastearate. The same operation as in Example 19 was performed. The results are shown in Table 2.

Examples 26 and 27
In Example 19, the same operation as in Example 25 was performed except that the pellet temperature immediately after cutting the strand with a cutter was 120 ° C. (Example 26) or 110 ° C. (Example 27). The results are shown in Table 2.

Example 28
In Example 19, the material added to the polymer having a viscosity average molecular weight of 15,000 was changed to 0.003% by weight of trisnonylphenyl phosphite, 0.005% by weight of trimethyl phosphate, and 0.045% by weight of stearic acid monoglyceride. The same operation as 19 was performed. The results are shown in Table 2.

Examples 29 and 30
The same operation as in Example 28 was performed except that the pellet temperature immediately after cutting the strand with a cutter in Example 28 was 120 ° C. (Example 29) or 110 ° C. (Example 30). The results are shown in Table 2.

Example 31
In Example 19, the substances to be added to the powder having a viscosity average molecular weight of 15,000 were 0.0015% by weight of phosphorous acid, 0.01% by weight of tris (2,4-di-tert-butylphenyl) phosphite, monoglyceride stearate The same evaluation as in Example 19 was performed except that the content was changed to 0.08% by weight. The results are shown in Table 2.

Examples 32 and 33
In Example 31, the same evaluation as in Example 31 was performed except that the pellet temperature immediately after cutting the strand with a cutter was 120 ° C. (Example 32) or 110 ° C. (Example 33). The results are shown in Table 2.

Example 34
In Example 19, the substances added to the powder having a viscosity average molecular weight of 15,000 were 0.01% by weight of 4,4′-biphenylenediphosphinic acid (2,4-di-tert-butylphenyl) and 0.08% by weight of stearic acid monoglyceride. The same operation as in Example 19 was carried out except that the percentage was changed to%. The results are shown in Table 2.

Examples 35 and 36
In Example 34, evaluation was performed in the same manner as in Example 34 except that the pellet temperature immediately after cutting the strand with a cutter was 120 ° C. (Example 35) or 110 ° C. (Example 36). The results are shown in Table 2.

Claims (7)

A substrate is formed by injection molding a pellet, and an optical disk manufacturing method using the substrate,
(I) The pellet is a pellet obtained by melt-extruding an aromatic polycarbonate resin having a viscosity average molecular weight of 13,000 to 18,000 into a strand, cooling with warm water and then cutting, and (ii) The pellets weighed 5 kg of the pellets, packed in a stack of two polyethylene bags having a width of 500 mm, a length of 864 mm, and a thickness of 0.08 mm, blown inflated with compressed air (with an internal volume of about 38 L), and then the pellets Put a polyethylene bag with a blender into the blender, and 25r. p. m. The amount of fine powder having a particle size of 1.0 mm or less after rotating the blender for 60 minutes and shaking is 250 ppm or less.
An optical disc manufacturing method characterized by the above. 2. The method of manufacturing an optical disk according to claim 1, wherein the amount of fine powder having a particle size of 1.0 mm or less is 150 ppm or less. 2. The method of manufacturing an optical disk according to claim 1, wherein the pellet has a diameter of 2.0 to 3.3 mm and a length of 2.5 to 3.5 mm. 2. The method for producing an optical disk according to claim 1, wherein the pellet is a pellet obtained by cutting the melt-extruded strand in a cooling tank filled with warm water and then cooling. 2. The method of manufacturing an optical disk according to claim 1, wherein the pellet is a pellet obtained by cutting the strand at a temperature such that the pellet temperature immediately after cutting the strand becomes 110 to 130 [deg.] C. 2. The method for producing an optical disk according to claim 1, wherein the aromatic polycarbonate resin is a polycarbonate resin obtained by using bisphenol A as a dihydric phenol. The method of manufacturing an optical disk according to claim 1, wherein the optical disk is a CD, a DVD, a DVD-ROM, or a DVD-RAM.