JP5019429B2 - Dispersion in container - Google Patents

Description

  The present invention relates to a dispersion in a container filled with a dispersion of abrasive particles, an abrasive liquid kit using the same, and a dispersion storage method.

  Recent memory hard disk drives are required to reduce the flying height of the magnetic head to reduce the unit recording area in order to increase the recording density for the purpose of increasing the capacity and reducing the diameter. Along with this, the surface quality required after polishing in the manufacturing process of the magnetic disk substrate is becoming stricter year by year. That is, it is necessary to reduce the surface roughness, micro waviness, roll-off and protrusions according to the low flying height of the head, and the allowable number of scratches per substrate surface is small according to the decrease in the unit recording area, Its size and depth are getting smaller and smaller.

  Also in the semiconductor field, high integration and high speed are advancing. In particular, miniaturization of wiring is required for high integration. As a result, in the manufacturing process of a semiconductor substrate, the depth of focus when exposing a photoresist becomes shallow, and further surface smoothness is desired.

  In response to such demands, a polishing liquid containing colloidal silica has been proposed in order to reduce the scratches (scratches, etc.) generated on the surface of the workpiece for the purpose of improving the surface smoothness (Patent Document). 1).

  When the polishing liquid (or dispersion liquid) containing colloidal silica is stored in a container for a long period of time, solid substances such as coarse particles are formed by water evaporation and drying from the silica dispersion droplets adhering to the inner wall of the container. There was a case to generate. This solid material was a cause of scratches generated when the object to be polished was polished.

In order to solve the above problems, by adjusting the filling state of the dispersion liquid of abrasive particles (hereinafter also simply referred to as “dispersion liquid”) to a specific one, the physical properties of the dispersion liquid, particularly, scratch reduction is reduced. Patent Document 2 proposes a dispersion liquid in a container that can maintain such polishing characteristics as a long-term.
JP 2002-327170 A JP 2006-130638 A

  However, even the dispersion in a container proposed in Patent Document 2 may deteriorate the polishing characteristics when placed in a high temperature state during the storage period.

  The present invention relates to a dispersion liquid in a container that can reduce scratches on an object to be polished even after polishing for a long time using a container made of an organic polymer material, a polishing liquid kit using the same, and a dispersion liquid Provide a storage method.

The container-containing dispersion of the present invention is a container-containing dispersion containing a container and a dispersion of abrasive particles filled in the container,
At least the inner wall of the container is made of an organic polymer material,
The organic polymer material is a dispersion in a container having an additive having a melting point of 60 ° C. or lower and a content of 500 ppm by weight or lower.

  The polishing liquid kit of the present invention is a polishing liquid kit containing the above-described dispersion in a container of the present invention and at least one selected from an acid and an acid salt.

The dispersion storage method of the present invention is a dispersion storage method for storing a dispersion of abrasive particles in a container,
At least the inner wall of the container is made of an organic polymer material,
The organic polymer material is a dispersion storage method in which the content of an additive having a melting point of 60 ° C. or less is 500 ppm by weight or less.

  According to the present invention, the generation of coarse particles in the dispersion can be suppressed, and the dispersion can be stably stored for a long period of time. Further, by using the dispersion liquid of the present invention in a polishing process of a substrate for precision parts for high density or high integration, scratches are reduced, and a high quality magnetic disk substrate and semiconductor element substrate having excellent surface properties. The substrate for precision parts such as can be manufactured.

  The container-containing dispersion of the present invention is a container-containing dispersion containing a container and a dispersion of abrasive particles filled in the container, and at least the inner wall of the container is composed of an organic polymer material. The organic polymer material is a dispersion in a container having an additive having a melting point of 60 ° C. or lower and a content of 500 ppm by weight or lower. Although the generation mechanism of coarse particles in the dispersion is not clear, while the dispersion is stored in the container, an additive such as an antioxidant is transferred from the organic polymer material constituting the inner wall of the container to the dispersion. It is thought that the abrasive particles in the dispersion liquid crystallize and coarse particles are generated with the eluted additive as a starting point. According to the container-containing dispersion of the present invention, since the amount of the additive eluted into the dispersion can be reduced, the generation of coarse particles in the dispersion can be suppressed. Thereby, the scratch of a to-be-polished object can be reduced also in grinding | polishing after storing for a long period of time. Here, the “coarse particles” mean particles having a particle diameter of 0.56 μm or more. The particle size of the coarse particles and the number in the dispersion are measured by “Accumizer 780” manufactured by Particle Sizing Systems, USA.

  As a container used for this invention, the inner wall part should just contain an organic polymer material. For example, a container made of only an organic polymer material, a container (for example, a bag-in-box) in which an inner bag made of an organic polymer material is covered with a protective material made of metal or the like may be used.

  The organic polymer material constituting the inner wall of the container is not particularly limited, but polyethylene, polypropylene, and poly (tetrafluoroethylene) are preferable, and polyethylene is more preferable from the viewpoint of reducing the adhesion residue of the abrasive particles.

  The organic polymer material has a content of additives having a melting point of 60 ° C. or less of 500 ppm by weight or less. An additive having a melting point of 60 ° C. or lower dissolves in the dispersion depending on the storage temperature, and becomes a starting point for the growth of coarse particles, but the additive elutes into the dispersion when the content of the additive is within the above range. Therefore, the generation of coarse particles in the dispersion that causes scratches can be suppressed. In order to suppress the generation of coarse particles more effectively, the content of the additive having a melting point of 60 ° C. or less is preferably 400 ppm by weight or less, more preferably 300 ppm by weight or less, and 100 ppm by weight or less. More preferably, it is even more preferable that the additive is not contained. Moreover, in order to suppress generation | occurrence | production of a coarse particle more effectively, it is preferable that content of the additive of melting | fusing point 5-60 degreeC is 500 weight ppm or less, and content of the additive of melting | fusing point 25-60 degreeC is 500. More preferably, the content is less than or equal to ppm by weight, and the content of the additive having a melting point of 40 to 60 ° C. is more preferably less than or equal to 500 ppm by weight. In particular, when an antioxidant, particularly a phenolic antioxidant, is included as an additive, this antioxidant is likely to be a starting point for coarse particle growth. According to the present invention, the content of the additive is within the above range. By doing so, generation | occurrence | production of a coarse particle can be suppressed more effectively. Specific examples of the phenolic antioxidant include 2,6-di-t-butyl-p-cresol, butylated hydroxyanisole, 2,6-di-t-butyl-4-ethylphenol, and n-octadecyl. -3- (3 ', 5'-di-t-butyl-4'-hydroxyphenyl) propionate, 2,2'-methylenebis (4-methyl-6-t-butylphenol), 2,2'-methylenebis (4 -Ethyl-6-t-butylphenol) and the like. In addition, content of the additive in organic polymer material can be measured with the measuring method as described in the Example mentioned later.

  Examples of the additive include an antioxidant, an ultraviolet absorber, an antistatic agent, a pigment, a dye, a nucleating agent, a filler, a lubricant, a flame retardant, and a plasticizer. Among them, the antioxidant is likely to be a starting point for crystal growth of the abrasive particles. Therefore, in order to more effectively suppress the generation of coarse particles, the content of the antioxidant in the organic polymer material is 500 ppm by weight or less. It is preferably 300 ppm by weight or less, more preferably 100 ppm by weight or less, and even more preferably not contained.

  As the abrasive particles, abrasives generally used for polishing can be used, for example, metal, metal or metalloid carbide, metal or metalloid nitride, metal or metalloid oxide, Metal or metalloid boride, diamond, etc. are mentioned. Examples of the metal or metalloid element include those belonging to Group 3A, 4A, 5A, 3B, 4B, 5B, 6A, 7A or Group 8 of the periodic table (long period type). Specific examples of the abrasive include silicon dioxide, aluminum oxide, cerium oxide, titanium oxide, zirconium oxide, silicon nitride, manganese dioxide, silicon carbide, zinc oxide, diamond and magnesium oxide.

  The abrasive particles are preferably colloidal particles from the viewpoint of reducing the surface roughness. As used herein, colloidal particles refer to abrasive particles having an average primary particle size of 200 nm or less. In addition, the said average particle diameter can be calculated | required from the observation image with a transmission electron microscope (TEM). Examples of colloidal particles include colloidal silica, colloidal alumina, and colloidal ceria. Among these, colloidal silica is preferable from the viewpoint of reducing scratches. Colloidal silica can be obtained, for example, by a production method in which an aqueous silica solution is used. The dispersion state of these abrasive particles is not particularly limited as long as it has fluidity. The abrasive particles can be used in combination of two or more. In addition, those obtained by surface modification or surface modification of these particles with a functional group, or those obtained by forming composite particles with a surfactant or other abrasive can be used.

  The average particle size of the primary particles of the abrasive particles such as the colloidal particles is a viewpoint of reducing scratches and a viewpoint of reducing the surface roughness (center line average roughness: Ra, Peak to Valley value: Rmax) of the object to be polished. From 1 to 50 nm is preferable. From the viewpoint of improving the polishing rate at the same time, the thickness is more preferably 3 to 50 nm, still more preferably 5 to 40 nm, and still more preferably 5 to 30 nm.

  The content of the abrasive particles in the dispersion is preferably 0.5 to 50% by weight and more preferably 0.5 to 45% by weight from the viewpoint of storage stability and scratch reduction.

  Examples of the medium used for the dispersion include water such as ion exchange water, distilled water, and ultrapure water, alcohol, and the like. The content of these media corresponds to the remainder of the entire dispersion excluding the abrasive particles and additives and other abrasives added as necessary, and the viewpoint of handling the dispersion and improving the polishing rate. From 50 to 99% by weight is preferable, and from 80 to 97% by weight is more preferable.

  From the viewpoint of reducing scratches, the number of coarse particles (silica particles having a particle size of 0.56 μm or more) in the dispersion is preferably 50,000 or less, more preferably 30,000 or less, even more preferably from the viewpoint of reducing scratches. Is 25,000 or less.

  The pH of the dispersion is preferably away from the isoelectric point of the abrasive particles from the viewpoint of dispersion stability of the abrasive particles and reduction of scratches. Although the isoelectric point varies depending on the type of abrasive particles, for example, since the isoelectric point of colloidal silica is 1 to 4, the pH is preferably 7 or more, more preferably 8 or more, and still more preferably 8.5 or more. Even more preferably, it is 9 or more, and from the viewpoint of the solubility of the abrasive particles, it is preferably 12 or less, more preferably 11 or less, still more preferably 10.5 or less.

  The dispersion in a container of the present invention having such a structure is, for example, a method of mixing the abrasive particles, water, and other abrasives as necessary, in a known method, and then putting them in a container, It can manufacture by the method of adding and mixing these components.

  Moreover, when putting the said dispersion liquid in a container, it is preferable to remove the coarse particle contained in this dispersion liquid. Alternatively, a dispersion in which coarse particles are reduced may be prepared by using a general dispersion method during the production of the dispersion, or a dispersion in which coarse particles are removed by using a general particle removal method. May be prepared. Examples of the dispersion method and particle removal method that can be used include a dispersion method using a high-pressure dispersion device such as a high-speed dispersion device or a high-pressure homogenizer, a sedimentation method using a centrifugal separator, or a microfiltration or ultrafiltration using a filter medium. The filtration method of these is mentioned. When processing using these, processing may be performed individually or in combination of two or more, and the processing order of the combination is not limited at all. Further, the processing conditions and the number of processing times can be appropriately selected and used.

  Among these, as a method for efficiently and economically removing the aggregates or coarse particles of the primary particles of the abrasive particles contained in the dispersion, microfiltration with a filter is preferably used.

  A depth type filter or a pleat type filter can be used as a filtering material for microfiltration. As the depth type filter, a filter of a bag type (manufactured by Sumitomo 3M Co., Ltd.) or a cartridge type (manufactured by Advantech Toyo Co., Ltd., Nippon Pole Co., CUNO Co., Ltd., Daiwabo Co., Ltd.) can be used.

  The depth type filter has a feature that the pore structure of the filter medium is rough on the inlet side, finer on the outlet side, and finer continuously or stepwise from the inlet side to the outlet side. That is, among coarse particles, large particles are collected near the inlet side, and small particles are collected near the outlet side. In addition, the larger the particle size of coarse particles, the easier it is to be removed because they are collected in multiple stages in the thickness direction of the filter. The shape of the depth filter may be a bag-like bag type or a hollow cylindrical cartridge type.

  A pleated filter is a hollow cylindrical cartridge type that is formed by filtering a filtering material into a pleat shape. Unlike depth-type filters that collect in each part in the thickness direction, pleated filters are said to be mainly collected on the filter surface because the filter material is thin and generally has high filtration accuracy. It is a feature. As the filter medium, a filter having an intermediate structure between a depth type and a pleat type can also be used.

  The filtration method may be a circulation type that repeatedly filters or a one-pass method. Alternatively, a batch method that repeats the one-pass method may be used. As the liquid passing method, when pressurized and passed, a circulation type pump is preferably used, and in the one-pass type, a pressure filtration method in which air pressure or the like is introduced into the tank can be used in addition to a pump.

  By appropriately selecting the pore structure of the filter, the particle size of the coarse particles to be removed can be controlled. The filter system may be single-stage filtration or multistage filtration by combination. For multi-stage filtration, it is possible to control the particle size of coarse particles to be removed (control of filtration accuracy) by appropriately selecting the pore size of the filter and the structure of the filter medium, and further selecting the processing order of the filter. In addition, the economy can be improved. That is, when a filter having a large pore structure is used in the front stage and a fine filter is used in the rear stage, the life of the filter can be extended as a whole, and thus the economy can be improved. Further, in the structure of the filter medium, if a depth type is used at the front stage and a pleat type is used at the rear stage, the life of the filter can be extended as a whole, so that the economy can be improved.

  The ratio of the liquid contact area to the total wall surface area in the container is 0.85 to 0.99 from the viewpoint of reducing scratches and preventing the liquid from overflowing from the container due to volume expansion of the dispersion due to temperature rise. Is more preferable, 0.90 to 0.98, more preferably 0.92 to 0.97. When the liquid contact area of the dispersion liquid with respect to the entire wall surface area in the container is within the above range, scratches on the object to be polished can be significantly reduced even during polishing after long-term storage. Here, the “total wall surface area in the container” means the surface area of the entire wall surface of the inner surface of the container in which the dispersion liquid can be put (when the container has a stopper, the stopper portion is also included). Further, the “wetted area” means the total wall surface area of the inner surface of the container that is in contact with the dispersion when the dispersion is placed in the container and the container is left standing. The total wall surface area and the wetted area in the container can be calculated by geometric calculation or by developing the container and measuring the dimensions. In this calculation, the surface of the container is assumed to be smooth, and irregularities of less than 1 mm are ignored.

  The container-containing dispersion of the present invention can be used as a raw material for the polishing composition. In this case, it is preferable to use what adjusted pH of the dispersion liquid to acidic as a polishing liquid composition. Specifically, the pH of the polishing composition is preferably from 0.1 to 7. The acidic polishing composition has less scratches than the alkaline polishing composition. The reason for this is not clear, but in an acidic atmosphere in which the abrasive particles do not strongly repel each other due to the surface charge, the aggregates of the abrasive primary particles contained in the polishing liquid composition or coarse particles thereof are not present. It is presumed that it is densely packed in the polishing portion and is less likely to receive a local load under the polishing pressure. The pH of the polishing composition is preferably determined according to the type and required characteristics of the object to be polished. When the material of the object to be polished is a metal material, it is preferably 6 or less from the viewpoint of improving the polishing rate. More preferably, it is 5 or less, More preferably, it is 4 or less. Moreover, from the viewpoint of the influence on the human body and the corrosion prevention of the polishing apparatus, it is preferably 0.5 or more, more preferably 1 or more, and still more preferably 1.4 or more. In particular, in a precision component substrate such as a Ni-P plated aluminum alloy substrate, the pH is preferably 0.5 to 6, more preferably 1.0 to 5, and even more preferably in consideration of the above viewpoint. 1.4-4.

  The pH of the polishing composition can be adjusted by the following acid and / or acid salt. Specifically, inorganic acids such as nitric acid, sulfuric acid, nitrous acid, persulfuric acid, hydrochloric acid, perchloric acid, phosphoric acid, phosphonic acid, phosphinic acid, pyrophosphoric acid, tripolyphosphoric acid, amidosulfuric acid, or salts thereof, 2-amino Ethylphosphonic acid, 1-hydroxyethylidene-1,1-diphosphonic acid, aminotri (methylenephosphonic acid), ethylenediaminetetra (methylenephosphonic acid), diethylenetriaminepenta (methylenephosphonic acid), ethane-1,1-diphosphonic acid, ethane- 1,1,2-triphosphonic acid, ethane-1-hydroxy-1,1-diphosphonic acid, ethane-1-hydroxy-1,1,2-triphosphonic acid, ethane-1,2-dicarboxy-1,2- Diphosphonic acid, methanehydroxyphosphonic acid, 2-phosphonobutane-1,2-dicarboxylic acid, 1-phosphonobutane- , 3,4-tricarboxylic acid, organic phosphonic acids such as α-methylphosphonosuccinic acid or their salts, aminocarboxylic acids such as glutamic acid, picolinic acid, aspartic acid or their salts, oxalic acid, nitroacetic acid, maleic acid And carboxylic acids such as oxaloacetic acid or salts thereof. Among these, inorganic acids, organic phosphonic acids, or salts thereof are preferable from the viewpoint of reducing scratches.

  Further, among inorganic acids or salts thereof, nitric acid, sulfuric acid, hydrochloric acid, perchloric acid or salts thereof are more preferable from the viewpoint of reducing scratches, and among organic phosphonic acids or salts thereof, viewpoints of reducing scratches. 1-hydroxyethylidene-1,1-diphosphonic acid, aminotri (methylenephosphonic acid), ethylenediaminetetra (methylenephosphonic acid), diethylenetriaminepenta (methylenephosphonic acid) or a salt thereof is more preferable. These acids or their salts may be used alone or in admixture of two or more.

  The counter ion (cation) constituting the above-described salt is not particularly limited, and specific examples include metal ions, ammonium ions, and alkylammonium ions. Specific examples of metal ions include ions of metals belonging to groups 1A, 1B, 2A, 2B, 3A, 3B, 4A, 6A, 7A, or 8 of the periodic table (long period type). From the viewpoint of reducing scratches, ammonium ions or ions of metals belonging to Group 1A are preferred.

  Moreover, another component can be mix | blended with the said polishing liquid composition as needed. For example, a thickener, a dispersant, a rust inhibitor, a basic substance, a surfactant and the like can be blended. Moreover, although it cannot generally limit by the material of to-be-polished material, generally an oxidizing agent can be added with a metal material from a viewpoint of improving a grinding | polishing rate. Examples of the oxidizing agent include hydrogen peroxide, permanganic acid, chromic acid, nitric acid, peroxo acid, oxyacid or a salt thereof, or an oxidizing metal salt.

  The polishing liquid kit of the present invention comprises the container-containing dispersion of the present invention and at least one selected from an acid and an acid salt. Examples of the acid and acid salt that can be used include acids and acid salts that can be used to adjust the pH of the polishing composition described above.

  In the polishing liquid kit, the acid and / or the salt of the acid may be in a state not mixed with the container-containing dispersion of the present invention, and is preferably stored in another acid-resistant container until use.

  According to the polishing liquid kit of the present invention, the polishing liquid composition can be prepared by mixing the dispersion and the acid and / or acid salt. The resulting polishing liquid composition is supplied, for example, between an organic polymer polishing cloth (polishing pad) or the like and the substrate to be polished, that is, the polishing liquid composition is sandwiched between polishing plates with a polishing pad attached thereto. The substrate is supplied to the polished surface of the substrate and used in a step of polishing the substrate to be polished by moving the polishing disk and / or the substrate to be polished under a predetermined polishing pressure. Since the polishing liquid kit of the present invention uses the above-described dispersion in a container of the present invention, the generation of scratches due to polishing can be suppressed.

  As the substrate to be polished, a substrate to be polished used for manufacturing a precision component substrate is suitable. Examples thereof include substrates to be used for the production of precision component substrates such as magnetic disk substrates such as magnetic disks and magneto-optical disks, optical disks, photomasks, optical lenses, optical mirrors, optical prisms, and semiconductor substrates. In the production of a semiconductor substrate, the polishing composition is used in a polishing process of a silicon wafer (bare wafer), a formation process of a buried element isolation film, a planarization process of an interlayer insulating film, a formation process of a buried metal wiring, a formation process of a buried capacitor, etc. Can be used.

  Examples of the material of the object to which the present invention can be applied include metals or semi-metals such as silicon, aluminum, nickel, tungsten, copper, tantalum, and titanium, or alloys thereof, glass, glassy carbon, and amorphous carbon. Examples thereof include ceramic materials such as alumina, silicon dioxide, silicon nitride, tantalum nitride, and titanium carbide, and resins such as polyimide resin. Among these, it is suitable for an object to be polished containing a metal such as aluminum, nickel, tungsten, copper, or an alloy containing these metals as a main component. For example, a Ni—P plated aluminum alloy substrate or a glass substrate such as crystallized glass or tempered glass is more suitable, and a Ni—P plated aluminum alloy substrate is particularly suitable.

  There is no restriction | limiting in particular in the shape of to-be-polished material, For example, the shape which has flat parts, such as disk shape, plate shape, slab shape, prism shape, and the shape which has curved surface parts, such as a lens, can be illustrated. Among them, it is suitable for polishing a disk-shaped workpiece.

  When there are a plurality of polishing steps in the production process of the substrate, it is preferable to apply the polishing liquid kit of the present invention after the second step, from the viewpoint of reducing scratches and surface roughness and obtaining excellent surface smoothness, It is particularly preferable to apply to the finish polishing step. The final polishing step refers to the last polishing step when there are a plurality of polishing steps.

  Next, the dispersion storage method of the present invention will be described. The dispersion storage method of the present invention is a storage method using the above-described container-containing dispersion of the present invention. Therefore, the description overlapping with the above is omitted.

  The dispersion storage method of the present invention is a dispersion storage method for storing a dispersion of abrasive particles in a container, wherein at least an inner wall portion of the container is composed of an organic polymer material, and the organic polymer material Is a dispersion storage method in which the content of an additive having a melting point of 60 ° C. or lower is 500 ppm by weight or lower. Thereby, since the quantity of the additive eluting in the dispersion liquid can be reduced as described above, the generation of coarse particles in the dispersion liquid that causes scratches can be suppressed. In order to suppress the generation of coarse particles more effectively, the content of the additive having a melting point of 60 ° C. or less is preferably 400 ppm by weight or less, more preferably 300 ppm by weight or less, and 100 ppm by weight or less. More preferably, it is even more preferred not to contain any additives. Moreover, in order to suppress generation | occurrence | production of a coarse particle more effectively, it is preferable that content of the additive of melting | fusing point 5-60 degreeC is 500 weight ppm or less, and content of the additive of melting | fusing point 25-60 degreeC is 500. More preferably, the content is less than or equal to ppm by weight, and the content of the additive having a melting point of 40 to 60 ° C. is more preferably less than or equal to 500 ppm by weight. In particular, when an antioxidant, particularly the above-mentioned phenolic antioxidant, is included as an additive, this antioxidant is likely to be a starting point for coarse particle growth. According to the present invention, the content of the additive is within the above range. By making it inside, the generation of coarse particles can be more effectively suppressed. In order to prevent the solvent of the dispersion from evaporating, it is preferable to store the dispersion in a sealed container.

  In the dispersion storage method of the present invention, in order to more effectively suppress the generation of coarse particles in the dispersion, the storage temperature of the dispersion is preferably 50 ° C. or less, more preferably 40 ° C. or less. Preferably, it is 30 degrees C or less. Further, from the viewpoint of stably storing the dispersion, the storage temperature of the dispersion is preferably 0 ° C. or higher, more preferably 5 ° C. or higher, and further preferably 10 ° C. or higher. From the viewpoint of stably storing the dispersion, the range of change in storage temperature is preferably within 15 ° C, more preferably within 10 ° C, and even more preferably within 5 ° C.

(Storage test method)
Colloidal silica dispersion (manufactured by DuPont Air Products Nanomaterials Co., Ltd., average particle size of primary particles 14 nm, silica particle concentration 40 wt%, pH 9 to 10) 1000 g, depth type filter with pore size 1 μm, depth type with pore size 0.5 μm After sequentially passing through the filter and an absolute filter having a pore diameter of 0.45 μm, each was put in each container shown in Table 1, and the air in the container was removed as much as possible and sealed. At this time, the ratio of the liquid contact area of the dispersion to the total wall surface area in the container was 0.95 or more. In addition, all the containers shown in Table 1 are 15L bag-in-boxes, and use the thing made from polyethylene as a material of an inner bag. And after putting the container containing the said dispersion liquid in a thermostat and storing at 60 degreeC, 40 degreeC, or 25 degreeC for 72 hours, the number of the 0.56 micrometer or more silica particle (coarse particle) in a dispersion liquid is set to the following. It measured on the measurement conditions shown. The results are shown in Table 1. The number of coarse particles in the dispersion before the storage test was 11,000 particles / mL. Moreover, content of the additive in the organic polymer material which comprises the container shown in Table 1 was measured with the measuring method of the additive content mentioned later.

(Conditions for measuring the number of coarse particles)
Measuring equipment: “Accuriser 780APS” manufactured by PSS
Injection loop volume: 1 mL
Flow rate: 60 mL / min Data Collection Time: 60 seconds Number of channels: 128

(Measurement method of additive content)
10 g of the organic polymer material constituting the container shown in Table 1 was dissolved in 100 mL of xylene heated to 110 ° C. Subsequently, the solution was dropped into 1 L of ethanol at 25 ° C. to reprecipitate the polymer component, and at the same time, the additive in the organic polymer material was dissolved in ethanol. Next, after reprecipitation was removed by filtration, ethanol was evaporated by an evaporator. The concentrated additive solution was analyzed by gas chromatography under the following conditions, and the additive content was calculated from the peak area.

(Gas chromatography conditions)
Measuring instrument: Agilient Technologies 6890N
Column: DB-IHT (inner diameter 0.25mm, length 30m, film thickness 0.1μm)
Temperature condition: 100 ° C to 380 ° C (10 ° C / min), 10 min at 380 ° C Split ratio: 1/50

(Evaluation of the number of nano scratches)
17.5% by weight of the dispersion after the storage, 35% by weight of Asahi Denka Co., Ltd., 0.4% by weight of hydrogen peroxide, 0.4% by weight of 62.5% sulfuric acid, manufactured by Teika, and manufactured by Solusia Japan A 60 wt% 1-hydroxyethylidene-1,1-diphosphonic acid (HEDP) aqueous solution was blended in an amount of 0.13% by weight to obtain a polishing liquid composition having a pH of 1.4. Using the resulting polishing composition, the substrate to be polished was polished under the following conditions, and the number of nanoscratches was measured by the following measuring method. The “nano scratch” is a fine scratch on the substrate surface having a depth of 10 nm or more and less than 100 nm, a width of 5 nm or more and less than 500 nm, and a length of 100 μm or more. Moreover, as a substrate to be polished, a Ni-P plated aluminum alloy substrate having a thickness of 1.27 mm, an outer diameter of 95 mm, and an inner diameter of 25 mm is prepared, and this is roughly polished with a polishing liquid containing an alumina abrasive in advance. Used (surface roughness Ra of the substrate surface after rough polishing by atomic force microscope: 1 nm).

(Polishing conditions)
Polishing tester: Double-sided polishing machine (9B type double-sided polishing machine, manufactured by Speed Fem Co.)
Polishing pad: Fujibow polyurethane pad (thickness 0.9 mm, average pore diameter 30 μm)
Upper platen rotation speed: 37.5 r / min Polishing liquid composition supply amount: 100 mL / min Polishing time: 4 minutes Polishing load: 9.8 kPa
Number of substrates loaded: 10

(Measurement conditions for the number of nano scratches)
Measuring equipment: “MicroMAX VMX-2100CSP” manufactured by VISION PSYTEC
Light source: 2Sλ (250 W) and 3Pλ (250 W) (both 100%)
Tilt angle: -6 degrees Magnification: Maximum (Field range: 1 / 120th of the total area)
Observation area: Total area (substrate with an outer diameter of 95 mm and an inner diameter of 25 mm)
Iris: notch
Evaluation: Randomly select 4 out of 10 substrates that have been put into the polishing tester, measure the number of nanoscratches (on each side) on both sides of each of the 4 substrates (total of 8) The total number of nanoscratches (lines) was divided by 8 to calculate the number of nanoscratches per substrate surface (lines / surface). The results are shown in Table 1.

  From the results of Table 1, in Examples 1 to 4 using containers having an additive having a melting point of 60 ° C. or less and 500 ppm by weight or less, generation of coarse particles as compared with Comparative Examples 1 to 3 having the same storage temperature Could be suppressed. As a result, the number of nano scratches could be reduced as compared with Comparative Examples 1 to 3.

  The container-containing dispersion liquid and the polishing liquid kit using the same according to the present invention are used, for example, for polishing a disk substrate such as a magnetic disk or an optical disk, or for polishing a photomask substrate, an optical lens, an optical mirror, an optical prism, or a semiconductor substrate. It can be used suitably. In addition, the dispersion storage method of the present invention is suitable for, for example, the above-described storage methods of polishing dispersions for objects to be polished.

Claims (7)

A container-containing dispersion containing a container and a dispersion of abrasive particles filled in the container,
At least the inner wall of the container is made of an organic polymer material,
The organic polymer material is a dispersion in a container in which the content of a phenolic antioxidant having a melting point of 60 ° C. or less is 300 ppm by weight or less. The abrasive grains, containers dispersion according to claim 1 is colloidal silica. The organic polymeric material, containers dispersion according to claim 1 or 2 is polyethylene. The dispersion in a container according to any one of claims 1 to 3 , wherein the dispersion has a pH of 7 or more. A polishing liquid kit comprising the container-containing dispersion according to any one of claims 1 to 4 and at least one selected from an acid and an acid salt. A dispersion storage method for storing a dispersion of abrasive particles in a container,
At least the inner wall of the container is made of an organic polymer material,
The organic polymer material is a dispersion storage method in which the content of a phenolic antioxidant having a melting point of 60 ° C. or less is 300 ppm by weight or less. The dispersion storage method according to claim 6 , wherein the storage temperature of the dispersion is 50 ° C. or less.