Polishing composition, polishing method, and polishing system

Abstract

The invention relates to a polishing composition, a polishing method, and a polishing system. The present disclosure pertains to a polishing composition for polishing an object to be polished containing a resin material, the polishing composition containing silica particles and water, and the silica particles having an average particle diameter D50 of 50 nm or more.

Description

Technical Field

[0001] The present invention relates to a polishing composition, a polishing method, and a polishing system. Background Art

[0002] Planarization techniques are used to improve the flatness of various substrate surfaces. Chemical mechanical polishing (CMP) is a common planarization technique used in the semiconductor industry. CMP uses a polishing composition containing abrasive particles such as silicon dioxide, silicon dioxide, and cerium oxide, an anticorrosive agent, and a surfactant to planarize the surface of an object to be polished, such as a semiconductor substrate.

[0003] Furthermore, substrates containing resin materials (hereinafter referred to as "polishing objects containing resin materials") are also becoming increasingly popular. Consequently, demand for polishing compositions suitable for polishing polishing objects containing resin materials is also increasing. For example, Japanese Patent Application Publication No. 2008-537704 (equivalent to U.S. Patent Application Publication No. 2006 / 0228999) discloses a polishing composition comprising abrasive grains, a pyrrolidone compound, and / or polyvinyl caprolactam, for polishing polishing objects containing resin materials. Summary of the Invention

[0004] Problems to be solved by the invention

[0005] The surface of the object to be ground comprising a resin material is usually finished to high quality through a lapping process and a subsequent lapping process. After the lapping process, a large number of defects are present on the surface of the object to be ground. In order to reduce these defects, in the lapping process, a grinding pad is pressed against the surface of the object to be ground and a lapping composition is supplied at its interface to grind the object to be ground. In this case, due to the local deviation of the lapping effect on the object to be ground, the object to be ground (also referred to as "the object to be ground after grinding") after grinding will be reduced in grinding efficiency or may have uneven thickness.

[0006] Therefore, for a polishing object comprising a resin material, a polishing composition is sought that can polish the resin material efficiently and reduce uneven thickness of the polished object.

[0007] Therefore, an object of the present invention is to provide a solution that can polish the resin material at a high speed and reduce unevenness in thickness of the polished object during polishing of the object made of the resin material.

[0008] Solutions for solving problems

[0009] The present inventors have conducted intensive research to solve the above-mentioned problems. As a result, the present inventors have found that the above-mentioned problems can be solved by the following means, thereby completing the present invention.

[0010] That is, the above-mentioned problems of the present invention can be solved by the following polishing composition, which is used for polishing an object to be polished made of a resin material, and contains silica particles and water, wherein the average particle size D of the silica particles is 50 It is 50nm or more. DETAILED DESCRIPTION

[0011] The following describes embodiments of the present invention. The embodiments shown here are illustrative for the purpose of concretizing the technical concept of the present invention and do not limit the present invention. Therefore, other practicable methods, usage methods, and application technologies that can be thought of by those skilled in the art without departing from the scope of the present invention are all included in the scope and gist of the present invention, and are included in the invention described in the claims and their equivalents. The embodiments described in this specification can form other embodiments by any combination.

[0012] In this specification, "X~Y" is used to include the numerical values ​​(X and Y) recorded before and after it as the lower limit and upper limit, and means "above X and below Y". In the case of recording multiple "X~Y", for example, when recorded as "X1~Y1, or X2~Y2", the disclosure with each numerical value as the upper limit, the disclosure with each numerical value as the lower limit, and the combination of these upper / lower limits are all disclosed (that is, become the legal basis for modification). Specifically, modification to above X1, modification to below Y2, modification to below X1, modification to above Y2, modification to X1~X2, modification to X1~Y2, etc. should all be regarded as legal. In this specification, unless otherwise specified, the operation and physical property measurements are measured under the conditions of room temperature (range above 20°C and below 25°C) / relative humidity above 40%RH and below 50%RH. In addition, when features or aspects of the present disclosure are described from the perspective of Markush groups, those skilled in the art will recognize that the present disclosure is described from the perspective of any individual component or subgroup of components of the Markush group. Furthermore, it should be understood that all embodiments and described combinations disclosed in this specification are disclosed in this application. In other words, it should be understood that they can serve as a basis for modification.

[0013] A first embodiment of the present invention is a polishing composition for polishing an object to be polished made of a resin material, the polishing composition comprising silica particles and water, wherein the average particle size D of the silica particles is 50It is 50nm or more.

[0014] A second embodiment of the present invention is a polishing composition for polishing an object to be polished made of a resin material, the polishing composition comprising silica particles, a polishing accelerator, and water, wherein the polishing accelerator is one or more selected from the group consisting of aluminum salts of monobasic acids, pyrrolidone compounds, and caprolactam compounds, and wherein the silica particles have a particle size at which the cumulative frequency from the smaller particle size side in a volume-based particle size distribution is 50% and is defined as D. 50 , the BET specific surface area is set as SA, and the D 50 When the calculated theoretical specific surface area is SA', the irregularity N represented by irregularity N=SA / SA' is 1.5 or more.

[0015] The polishing compositions of the first and second aspects having the above-described configurations polish resin materials at high speeds and reduce thickness unevenness of the polished object after polishing.

[0016] A third embodiment of the present invention is a polishing method comprising the step of supplying a polishing composition between an object to be polished made of a resin material and a polishing pad to polish the object to be polished, wherein the polishing composition contains silica particles and water, and the average particle size D of the silica particles is 1.5-2.0. 50 It is 50nm or more.

[0017] A fourth aspect of the present invention is a polishing method comprising the step of supplying a polishing composition between an object to be polished made of a resin material and a polishing pad to polish the object to be polished, wherein the polishing composition contains silica particles, a polishing accelerator, and water, wherein the polishing accelerator is one or more selected from the group consisting of aluminum salts of monobasic acids, pyrrolidone compounds, and caprolactam compounds, and wherein the silica particles have a particle size at which the cumulative frequency from the smaller particle size side in a volume-based particle size distribution is 50% as D. 50 , the BET specific surface area is set as SA, and the D 50 When the calculated theoretical specific surface area is SA', the irregularity N represented by irregularity N=SA / SA' is 1.5 or more.

[0018] A fifth embodiment of the present invention is a polishing system comprising: an object to be polished made of a resin material, a polishing pad, and a polishing composition, wherein the polishing composition contains silica particles and water; the average particle size D of the silica particles is 50 The surface of the polishing object is in contact with the polishing pad and the polishing composition.

[0019] A sixth aspect of the present invention is a polishing system comprising: an object to be polished comprising a resin material, a polishing pad, and a polishing composition, wherein the polishing composition contains silica particles, a polishing accelerator, and water; the polishing accelerator is one or more selected from the group consisting of aluminum salts of monobasic acids, pyrrolidone compounds, and caprolactam compounds; and the silica particles are arranged such that a particle size D is the particle size at which the cumulative frequency of the particle size distribution of the silica particles from the smaller particle size side reaches 50%. 50 , the BET specific surface area is set as SA, and the D 50 When the calculated theoretical specific surface area is SA', the irregularity N represented by irregularity N=SA / SA' is 1.5 or more; and the surface of the polishing object is brought into contact with the polishing pad and the polishing composition.

[0020] According to the polishing method and / or polishing system having the configurations of the third to sixth aspects, it is possible to polish a resin material at a high speed and reduce uneven thickness of the polished object after polishing.

[0021] The present invention is described in detail below. The "polishing composition of this embodiment" herein is a configuration common to the first to sixth embodiments. Furthermore, "polishing removal rate" herein is synonymous with "polishing rate" and "polishing rate."

[0022] [Object to be polished]

[0023] The polishing composition of this embodiment is suitable for polishing an object containing a resin material. The polishing composition of this embodiment is particularly suitable for polishing a substrate formed of a resin material, and the technical effects of the present invention are fully exerted when polishing such a substrate.

[0024] The resin material contained in the polishing object is not particularly limited. As an example, poly(meth)acrylates ((meth)acrylic resins) such as polymethyl methacrylate (PMMA) and polycyclohexyl methacrylate (PCHMA); polyethylene terephthalate (PET); polycarbonate (PC); polyvinyl chloride (PVC); polystyrene (PS); thiocarbamate resins; polysulfide; episulfide resin (Episulfide resin); Polyolefins such as polyethylene (PE), ultra-high molecular weight polyethylene (UHMWPE), and polypropylene (PP); polyureaurethane; poly(meth)(thio)acrylate; allyl diglycidyl carbonate; polybenzoxazole (PBO); polybutylene terephthalate (PBT); polyimide (PI); polyamide (PA); epoxy resin; urethane acrylate resin; polyester resin; unsaturated polyester resin; phenolic resin; polynorbornene resin; polyacetal (POM); modified polyphenylene ether (m-PPE); syndiotactic polystyrene (SPS); amorphous polyarylate (PAR); polysulfone (PSF); polyethersulfone (PES); polyphenylene sulfide (PPS); polyetheretherketone (PEEK); polyetherimide (PEI); benzocyclobutene (BCB); fluororesin; and liquid crystal polymer (LCP); etc.

[0025] In the grinding composition of this mode, as the resin material contained in the grinding object, it is preferably an optical resin.That is, according to one embodiment, in the grinding composition of this mode, the resin material is an optical resin material.Optical resin is a light-transmitting resin, as a film-like, plate-like (for example, liquid crystal screen, light-emitting display, light-emitting mark, logo, lighting and other surface light source devices light waveguide, diffuser, light guide plate (wave guide), polarizing plate), lens-like optical components (for example, film, substrate, prism sheet etc. used in liquid crystal display device; lens in the lens system for reading the signal of optical disc device, Fresnel lens for projection screen, cylindrical lens etc.) material use.

[0026] Examples of such optical resins (light-transmitting resins) include poly(meth)acrylates ((meth)acrylic resins) such as polymethyl methacrylate (PMMA) and polycyclohexyl methacrylate (PCHMA); polyethylene terephthalate (PET); polycarbonate (PC); polyvinyl chloride (PVC); polystyrene (PS); thiourethane resins; polysulfides; episulfide resins; polyolefins such as polyethylene (PE), ultra-high molecular weight polyethylene (UHMWPE), and polypropylene (PP); polyureaurethane; poly(meth)(thio)acrylate; allyl diglycidyl carbonate; polyimide (PI); polyamide (PA); polyester resins; and their derivatives. Therefore, the polishing composition of this embodiment is preferably used for polishing an object to be polished comprising one or more selected from the group consisting of poly(meth)acrylates (preferably polymethyl methacrylate (PMMA), polycyclohexyl methacrylate (PCHMA), etc.), polyethylene terephthalate (PET), polycarbonate (PC), polyvinyl chloride (PVC), polystyrene (PS), thiourethane resins, polysulfides, episulfide resins, polyolefins (preferably polyethylene (PE), ultrahigh molecular weight polyethylene (UHMWPE), polypropylene (PP), etc.), polyureaurethanes, poly(meth)(thio)acrylates, allyl diglycidyl carbonate, polyimide (PI), polyamide (PA), polyester resins, and derivatives thereof. Thus, the polishing composition can efficiently achieve the effects of high-speed polishing of resin materials and reducing uneven thickness of the polished object.

[0027] The resin material contained in the object to be polished preferably comprises one or more selected from the group consisting of thiourethane resins, episulfide resins, polycarbonates, polymethyl methacrylates, and polypropylene. These resin materials may be used alone or in combination of two or more. The inclusion of these resin materials in the object to be polished allows for efficient high-speed polishing of the resin material and reduced thickness unevenness of the object after polishing.

[0028] The grinding composition of this mode, by grinding the thinner grinding object, can efficiently bring into play the effect of high-speed grinding of resin material and reducing the uneven thickness of the grinding object after grinding. That is, the thickness of the grinding object (grinding object before grinding) is preferably below 3.0mm, more preferably below 2.0mm, further preferably below 1.0mm, particularly preferably below 0.8mm, most preferably below 0.6mm. According to one embodiment, in the grinding composition of this mode, the average thickness of the grinding object before grinding is below 1mm. In the grinding of the grinding composition based on this mode, the thickness change of the grinding object before and after grinding can be about 0.1mm. Therefore, the thickness of the grinding object (grinding object after grinding) is preferably below 3.0mm, more preferably below 2.0mm, further preferably below 1.0mm, further more preferably below 0.9mm, particularly preferably below 0.8mm, most preferably below 0.6mm. According to one embodiment, in the grinding composition of this mode, the average thickness of the grinding object after grinding is below 1mm. In this specification, the average thickness of the object to be polished can be measured using a micrometer or the like.

[0029] In the polishing composition of this mode, the object to be polished (the object to be polished before polishing) is preferably flat. In this specification, flat refers to that the GBIR (global backside reference overall flatness, Global Backside Ideal Range) measured in the embodiments described later is less than 2.0 μm. The GBIR of the object to be polished (the object to be polished before polishing) is more preferably less than 1.5 μm, further preferably 1.2 μm, particularly preferably less than 1.0 μm, and most preferably less than 0.8 μm. The lower limit of GBIR is 0 μm. GBIR is as follows: the entire back surface of the object to be polished is adsorbed on a flat chuck surface, the back surface is used as a reference plane, and the height from the above-mentioned reference plane is measured for the entire surface of the wafer, representing the distance from the highest height to the lowest height. GBIR adopts the value obtained by the determination method described in the embodiments described later.

[0030] Therefore, the polishing composition of this embodiment is suitable for polishing a flat object (i.e., GBIR less than 2.0 μm) having a thickness of 1.5 mm or less (preferably 1 mm or less, more preferably 1.0 mm or less, further preferably 0.8 mm or less, particularly preferably 0.7 mm or less, and most preferably 0.6 mm or less) (the object to be polished before polishing). Thus, the resin material can be polished at high speed and the uneven thickness of the polished object can be effectively reduced.

[0031] [Polishing composition]

[0032] The present invention includes a first embodiment and a second embodiment as the polishing composition. Hereinafter, the configuration of the main components contained in the polishing composition of the first embodiment and the configuration of the main components contained in the polishing composition of the second embodiment will be described in order.

[0033] <<Polishing composition of the first embodiment>> 1

[0034] The polishing composition of the first embodiment is a polishing composition for polishing an object to be polished made of a resin material, the polishing composition containing silica particles and water, wherein the average particle size D of the silica particles is 50 It is 50nm or more.

[0035] [Silicon dioxide particles]

[0036] The polishing composition of the first embodiment contains silica particles as abrasive particles. The abrasive particles mechanically polish the object to be polished, increasing the polishing removal rate. The silica particles have an appropriate hardness to reduce defects in the resin material.

[0037] <2 times particle size D 50 >

[0038] In the polishing composition of the first embodiment, the silica particles have a D 50 (The particle size at which the cumulative frequency from the smaller particle size side is 50% in the volume-based particle size distribution (the secondary particle size at which the cumulative frequency from the smaller particle size side is 50%)) is 50 nm or more (0.05 μm or more). 50 If the thickness is less than 50 nm, the polishing removal rate of the resin material (polishing object) decreases.

[0039] For the grinding of an object to be ground comprising a resin material, first, the object to be ground is ground through a grinding process to adjust the thickness, but at this time, a large number of defects remain on the surface of the object to be ground. In order to reduce these defects, the surface of the object to be ground is ground using a grinding composition in the grinding process, but due to the local deviation of the grinding effect on the object to be ground, there is a worry that the thickness unevenness caused by grinding will occur in the object to be ground. For example, as the grinding time passes, the supplied grinding composition accumulates on the outer edge of the object to be ground, etc., which will cause the local deviation of the grinding effect to become larger. That is, in the grinding process, the more time is spent to reduce defects, the more the tendency of uneven thickness increases. Therefore, for the object to be ground comprising a resin material, a further high grinding speed is required. The present inventors have found that by making these abrasive grains have a specific particle size or more, a significantly high grinding speed can be brought to reduce the uneven thickness of the object to be ground after grinding. In other words, using the grinding composition of the first embodiment, it is possible to grind at a significantly high grinding speed and reduce the local deviation of the grinding effect that may occur during grinding, thereby maintaining or improving the flatness of the object to be ground. It is also found that utilizing the polishing composition of the first embodiment, for the polishing object surface after grinding, the surface roughness (Rms) is low and the scratches are few. That is, utilizing the polishing composition of the first embodiment, the defects on the polishing object surface can be reduced, and the surface quality of the polishing object after grinding can also be improved.

[0040] As mentioned above, by making the D of the silica particles 50 The silica particles have a diameter of 50 nm or more (0.05 μm or more), which can more effectively improve the polishing removal rate of the resin material and reduce the thickness unevenness of the polished object after polishing. 50 It is preferably greater than 0.05 μm (greater than 50 nm), more preferably greater than 0.06 μm, further preferably greater than 0.08 μm, particularly preferably greater than 0.1 μm, and most preferably greater than 0.15 μm. 50 It is preferably 1 μm or less, can be 0.8 μm or less, more preferably 0.5 μm or less, further preferably 0.3 μm or less, particularly preferably 0.25 μm or less, and most preferably 0.2 μm or less. According to one embodiment, the D of the silica particles is 50 It is 50 nm or more and less than 200 nm.

[0041] The D of silica particles 10 It is the particle size at which the cumulative frequency from the smaller particle size side is 10% in the volume-based particle size distribution (the secondary particle size at which the cumulative frequency from the smaller particle size side is 10%). 50 If the D of the silica particles is 50 nm or more, 10There are no particular restrictions, but the particle size is preferably 0.005 μm or larger, more preferably 0.01 μm or larger, further preferably 0.02 μm or larger, particularly preferably 0.05 μm or larger, and most preferably 0.07 μm or larger. 10 It is preferably 0.5 μm or less, can be 0.3 μm or less, more preferably 0.25 μm or less, further preferably 0.2 μm or less, particularly preferably 0.15 μm or less, and most preferably 0.13 μm or less. 10 When the amount falls within the above range, the improvement in the polishing removal rate of the resin material and the reduction in thickness unevenness of the polished object after polishing can be more effectively achieved.

[0042] The D of silica particles 90 It is the particle size at which the cumulative frequency from the smaller particle size side is 90% in the volume-based particle size distribution (the secondary particle size at which the cumulative frequency from the smaller particle size side is 90%). 50 If the D of the silica particles is 50 nm or more, 90 There are no particular restrictions, but the particle size is preferably 0.1 μm or larger, more preferably 0.12 μm or larger, further preferably 0.15 μm or larger, particularly preferably 0.2 μm or larger, and most preferably 0.3 μm or larger. 90 The diameter of the silica particles is preferably 1.5 μm or less, can be 1.2 μm or less, more preferably 1.0 μm or less, further preferably 0.8 μm or less, particularly preferably 0.7 μm or less, and most preferably 0.5 μm or less. 90 When the amount falls within the above range, the improvement in the polishing removal rate of the resin material and the reduction in thickness unevenness of the polished object after polishing can be more effectively achieved.

[0043] The D of silica particles 90 Relative to D 10 The ratio (hereinafter referred to as "D 90 / D 10 ”) is preferably 1.2 or more, more preferably 1.5 or more, further preferably 1.8 or more, particularly preferably 2.0 or more, and most preferably 2.5 or more. 90 / D 10 It is preferably 6.5 or less, more preferably 6.0 or less, further preferably 5.0 or less, particularly preferably 4.0 or less, and most preferably 3.5 or less. 90 / D 10 When the amount falls within the above range, the improvement in the polishing removal rate of the resin material and the reduction in thickness unevenness of the polished object after polishing can be more effectively achieved.

[0044] According to one embodiment, in the polishing composition of the first embodiment, the particle size at which the cumulative frequency of the silica particles from the smaller particle size side is 10% in the volume-based particle size distribution is defined as D 10 The particle size at which the cumulative frequency of the silica particles is 90% from the smaller particle size side in the volume-based particle size distribution is defined as D 90 When the D 90 Relative to D 10 The ratio (D 90 / D 10 ) is 2.0 or above.

[0045] The D of silica particles 10 、D 50 , and D 90 The particle size distribution of the particles can be determined by dynamic light scattering, laser diffraction, laser scattering, or pore resistance methods. In this specification, the values ​​determined based on the cumulative frequency from the smaller particle size side, the 10% particle size, the 50% particle size, and the 90% particle size in a volume-based particle size distribution measured using a laser diffraction particle size distribution analyzer are used. More specifically, the particle size distribution can be determined by the methods described in the Examples.

[0046] <Alienation N>

[0047] The silica particles contained in the polishing composition of the first embodiment preferably have a particle size D at which the cumulative frequency from the smaller particle size side in the volume-based particle size distribution is 50%. 50 , set the BET specific surface area as SA, and set the D 50 When the calculated theoretical specific surface area is SA', the degree of irregularity N, expressed as degree of irregularity N = SA / SA', is 1.2 or greater. The degree of irregularity N is a parameter that indicates the degree to which the particle's external shape is deformed relative to a true sphere of the same particle diameter. A larger degree of irregularity N, i.e., greater than 1, indicates a greater degree of particle shape deformation. A degree of irregularity N of 1 indicates that the particle is a true sphere. The silica particles of the first embodiment preferably have a degree of irregularity N of 1.2 or greater (more preferably 1.5 or greater), resulting in a greater degree of particle shape deformation.

[0048] In the grinding of the grinding object comprising resin material, the surface defects of the grinding object caused by the grinding process have been carefully studied, while also reducing the problem of uneven thickness. As a result, the inventors have also found that the deformation of the shape of the abrasive can bring a significantly high grinding speed, thereby reducing the uneven thickness of the grinding object after grinding. When the anomaly N of the silica particles is more than 1.2, it is possible to reduce the defects on the grinding object surface and also to improve the surface quality of the grinding object after grinding. The upper limit of the anomaly N of the silica particles is not particularly limited, and is practically less than 3.0. The anomaly N of the silica particles is preferably more than 1.6, more preferably more than 1.7, further preferably more than 1.8, and particularly preferably more than 1.9.

[0049] The BET specific surface area SA of the silica particles and the theoretical specific surface area SA′ of the silica particles used to calculate the irregularity N can be calculated in the same manner as described in the polishing composition of the second embodiment described below.

[0050] The shape of the silica particles is not particularly limited. Examples of the shape of the silica particles include polyhedral prisms such as triangular prisms and quadrangular prisms, cylindrical shapes, straw bag shapes with a cylindrical center bulging outwards relative to the ends, ring shapes with a through-hole in the center of a disk, plate shapes, a so-called cocoon shape with a constricted center, a so-called associated spherical shape formed by integrating multiple particles, a so-called konpeito shape with multiple protrusions on the surface, a rugby ball shape, a cone shape, a truncated cone shape, a pyramid shape, a truncated pyramid shape, a hemisphere shape, a needle shape, and an irregular shape.

[0051] The concentration (content) of the silicon dioxide granules in the grinding composition is not particularly limited, and relative to the gross mass of the grinding composition, is preferably more than 0.1 mass %, more preferably more than 0.5 mass %, further preferably more than 1 mass %, further more preferably more than 2 mass %, particularly preferably more than 5 mass %, most preferably more than 10 mass %. Along with the concentration of silicon dioxide granules becomes large, the grinding removal rate further improves, and the uneven thickness of the grinding object after grinding can be reduced. In addition, the concentration (content) of silicon dioxide granules is preferably less than 50 mass %, more preferably less than 40 mass %, further preferably less than 35 mass %, further more preferably less than 30 mass %, particularly preferably less than 25 mass %, most preferably less than 20 mass %. When being above-mentioned scope, the grinding removal rate of resin material can be further improved, the uneven thickness of the grinding object after grinding can be reduced. A preferred example of the concentration (content) of the silica particles is preferably 0.1% by mass or more and 50% by mass or less, more preferably 0.5% by mass or more and 40% by mass or less, further preferably 1% by mass or more and 35% by mass or less, further more preferably 2% by mass or more and 30% by mass or less, particularly preferably 5% by mass or more and 25% by mass or less, and most preferably 10% by mass or more and 20% by mass or less. The silica particles may be used alone or in combination of two or more. When two or more silica particles are used, the concentration (content) of the silica particles is the total amount.

[0052] As silica particles, colloidal silica is preferred. As the production method of colloidal silica, sodium silicate method, sol-gel method, etc. can be cited, and colloidal silica produced by any production method is suitable for use. In order to make the D of silica particles (preferably colloidal silica) 50 The particle size of the silica particles can be controlled by selecting the conditions (e.g., reaction temperature, reaction concentration, etc.) during the above-mentioned manufacturing process. It should be noted that commercially available silica particles can be used. In this case, the D 50 The silica particles used in the polishing composition of the first embodiment are selected.

[0053] In addition, regarding the D of silica particles 10 、D 90 The degree of irregularity N can also be appropriately controlled by selecting the conditions for producing the silica particles.

[0054] [Grinding accelerator]

[0055] The polishing composition of the first embodiment preferably includes a polishing accelerator. The polishing accelerator is one or more selected from the group consisting of aluminum salts of monobasic acids, pyrrolidone compounds, and caprolactam compounds. The polishing accelerator assists polishing by the abrasive. According to one embodiment, the polishing composition of the first embodiment further includes a polishing accelerator, wherein the polishing accelerator is one or more selected from the group consisting of aluminum salts of monobasic acids, pyrrolidone compounds, and caprolactam compounds.

[0056] As the aluminum salt of a monoprotic acid, the aluminum salt of a monoprotic inorganic acid or a monoprotic organic acid can be enumerated. As the specific example of a monoprotic inorganic acid, nitric acid, hydrochloric acid, perchloric acid, nitrous acid, hypochlorous acid, hypophosphorous acid (phosphinic acid; H2PO(OH)), aminosulfonic acid etc. can be enumerated. As the specific example of a monoprotic organic acid, lactic acid, nicotinic acid, acetic acid, formic acid, propionic acid, valeric acid, hexanoic acid, caprylic acid, capric acid, cyclohexanecarboxylic acid, phenylacetic acid, benzoic acid, crotonic acid, methacrylic acid, methanesulfonic acid, ethanesulfonic acid, aminoethanesulfonic acid, benzenesulfonic acid, p-toluenesulfonic acid, 1-naphthalenesulfonic acid, 2-naphthalenesulfonic acid etc. can be enumerated. Their content is the content after removing the hydration water when the aluminum salt of a monoprotic acid has hydration water. It should be noted that, as the preferred example of the aluminum salt of a monoprotic acid, aluminum nitrate, aluminum chloride etc. can be enumerated.

[0057] The concentration (content) of the aluminum salt of the monoprotic acid in the grinding composition is not particularly limited, and relative to the gross mass of the grinding composition, is preferably more than 0.1 mass %, more preferably more than 0.5 mass %, further preferably more than 1 mass %, particularly preferably more than 2 mass %, particularly preferably more than 3 mass %, most preferably more than 5 mass %.Along with the concentration of the aluminum salt of the monoprotic acid becomes large, the grinding removal rate further improves, and the uneven thickness of the grinding object after grinding can be reduced.In addition, the concentration (content) of the aluminum salt of the monoprotic acid is preferably below 25 mass %, more preferably below 20 mass %, further preferably below 18 mass %, further more preferably below 15 mass %, particularly preferably below 12 mass %, most preferably below 10 mass %.When being above-mentioned scope, the grinding removal rate of resin material can be further improved, the uneven thickness of the grinding object after grinding can be reduced. A preferred example of the concentration (content) of the aluminum salt of the monobasic acid is preferably 0.1% by mass or more and 25% by mass or less, more preferably 0.5% by mass or more and 20% by mass or less, further preferably 1% by mass or more and 18% by mass or less, further more preferably 2% by mass or more and 15% by mass or less, particularly preferably 3% by mass or more and 12% by mass or less, and most preferably 5% by mass or more and 10% by mass or less, relative to the total mass of the polishing composition. The aluminum salt of the monobasic acid can be used alone or in combination of two or more. When two or more aluminum salts of the monobasic acid are used, the concentration (content) of the aluminum salt of the monobasic acid is the total amount.

[0058] Examples of the pyrrolidone compound include 2-pyrrolidone or 2-pyrrolidone derivatives, and polymers having a structural unit derived from a 2-pyrrolidone derivative. Examples of the 2-pyrrolidone derivative include 2-pyrrolidone, N-octyl-2-pyrrolidone, N-dodecyl-2-pyrrolidone, N-methyl-2-pyrrolidone, N-ethyl-2-pyrrolidone, N-cyclohexyl-2-pyrrolidone, N-hydroxyethyl-2-pyrrolidone, N-butyl-2-pyrrolidone, N-hexyl-2-pyrrolidone, N-decyl-2-pyrrolidone, N-octadecyl-2-pyrrolidone, N-hexadecyl-2-pyrrolidone, and N-vinyl-2-pyrrolidone. Examples of polymers having structural units derived from 2-pyrrolidone derivatives include homopolymers of N-vinyl-2-pyrrolidone (hereinafter also referred to as "polyvinyl pyrrolidone" or "PVP") or copolymers thereof. These pyrrolidone compounds may be used alone or in combination of two or more. Among these, polyvinyl pyrrolidone is preferred as the pyrrolidone compound.

[0059] The concentration (content) of the pyrrolidone compound in the grinding composition is not particularly limited. Relative to the gross mass of the grinding composition, it is preferably more than 0.001 mass %, more preferably more than 0.003 mass %, further preferably more than 0.005 mass %, particularly preferably more than 0.007 mass %, particularly preferably more than 0.008 mass %, and most preferably more than 0.01 mass %. As the concentration of the pyrrolidone compound becomes larger, the grinding removal rate is further improved, and the uneven thickness of the grinding object after grinding can be reduced. In addition, the concentration (content) of the pyrrolidone compound is preferably less than 3 mass %, more preferably less than 2 mass %, further preferably less than 1.5 mass %, further more preferably less than 1.2 mass %, particularly preferably less than 1 mass %, and most preferably less than 0.5 mass %. When it is within the above range, the grinding removal rate of the resin material can be further improved, and the uneven thickness of the grinding object after grinding can be reduced. A preferred example of the concentration (content) of the pyrrolidone compound is preferably 0.001% by mass to 3% by mass, more preferably 0.003% by mass to 2% by mass, further preferably 0.005% by mass to 1.5% by mass, particularly preferably 0.007% by mass to 1.2% by mass, particularly preferably 0.008% by mass to 1% by mass, and most preferably 0.01% by mass to 0.5% by mass, relative to the total mass of the polishing composition. When two or more pyrrolidone compounds are used, the concentration (content) of the pyrrolidone compounds is expressed as a total amount.

[0060] In the polishing composition of the first embodiment, according to one embodiment, the pyrrolidone compound is polyvinyl pyrrolidone. In this case, the weight average molecular weight (Mw) of the polyvinyl pyrrolidone is preferably 2,000 or more, more preferably 3,000 or more, further preferably 5,000 or more, and particularly preferably 7,500 or more. In addition, the weight average molecular weight (Mw) of the polyvinyl pyrrolidone is preferably 900,000 or less, more preferably 500,000 or less, further preferably 250,000 or less, particularly preferably 100,000 or less, and most preferably 55,000 or less. As long as the weight average molecular weight of the polyvinyl pyrrolidone is within the above range, it is possible to more efficiently enhance the polishing removal rate of the resin material and reduce the uneven thickness of the polished object after polishing.

[0061] Examples of caprolactam compounds include ε-caprolactam or its derivatives, and polymers having structural units derived from ε-caprolactam or its derivatives. Caprolactam compounds can be used as substitutes for pyrrolidone compounds. Examples of caprolactam compounds include ε-caprolactam and nylon 6.

[0062] The concentration (content) of the caprolactam compound in the polishing composition is not particularly limited, but is preferably 0.01% by mass or more, more preferably 0.05% by mass or more, and even more preferably 0.1% by mass or more, relative to the total mass of the polishing composition. Furthermore, the concentration (content) of the caprolactam compound is preferably 5% by mass or less, more preferably 2% by mass or less, and even more preferably 1% by mass or less. As long as the content of the caprolactam compound is within the above range, it is possible to more efficiently enhance the polishing removal rate of the resin material and reduce the uneven thickness of the polished object after polishing.

[0063] The pyrrolidone compound and the caprolactam compound may be commercially available products or may be synthesized by a known method.

[0064] According to one embodiment, in the polishing composition of the first embodiment, the polishing accelerator comprises an aluminum salt of a monobasic acid and a pyrrolidone compound. By including the aluminum salt of a monobasic acid and the pyrrolidone compound as polishing accelerators in the polishing composition of the first embodiment, the polishing removal rate of the resin material can be more effectively increased, and uneven thickness of the polished object can be reduced after polishing.

[0065] [water]

[0066] The polishing composition of the first embodiment contains water. Water disperses or dissolves the various components. From the perspective of preventing the polishing composition from being affected by impurities on other components, it is preferred to use water of the highest possible purity. Specifically, pure water, ultrapure water, or distilled water is preferably used, which has been filtered to remove foreign matter after removing impurity ions using an ion exchange resin. In addition, an organic solvent or the like may be included as a dispersion medium to control the dispersibility of other components in the polishing composition.

[0067] <<Polishing composition of the second embodiment>>

[0068] A second embodiment of the polishing composition is a polishing composition for polishing an object to be polished made of a resin material, the polishing composition comprising silica particles, a polishing accelerator, and water, wherein the polishing accelerator is one or more selected from the group consisting of aluminum salts of monobasic acids, pyrrolidone compounds, and caprolactam compounds, and wherein the silica particles have a particle size at which the cumulative frequency from the smaller particle size side in a volume-based particle size distribution is 50% and is defined as D. 50 , the BET specific surface area is set as SA, and the D 50 When the calculated theoretical specific surface area is SA', the irregularity N represented by irregularity N=SA / SA' is 1.5 or more.

[0069] [Silicon dioxide particles]

[0070] The polishing composition of the second embodiment contains silica particles as abrasive particles. The abrasive particles mechanically polish the object to be polished, thereby increasing the polishing removal rate. The silica particles have an appropriate hardness to reduce defects in the resin material.

[0071] <Alienation N>

[0072] The silica particles contained in the polishing composition of the second embodiment have a particle size at which the cumulative frequency from the smaller particle size side in the volume-based particle size distribution is 50% as D 50 , set the BET specific surface area as SA, and set the D 50 When the calculated theoretical specific surface area is SA', the degree of irregularity N, expressed as N = SA / SA', is 1.5 or greater. The degree of irregularity N represents the degree to which the particle's external shape is deformed relative to a true sphere of the same particle diameter. A larger degree of irregularity N, i.e., greater than 1, indicates a greater degree of particle shape deformation. A degree of irregularity N of 1 indicates a true sphere. The silica particles of the second embodiment have a degree of irregularity N of 1.5 or greater, indicating a significant degree of particle shape deformation.

[0073] When grinding an object to be ground comprising a resin material, the object to be ground is first ground through a grinding process to adjust the thickness, but a large number of defects remain on the surface of the object to be ground. In order to reduce these defects, a grinding composition is used to grind the surface of the object to be ground during the grinding process. However, due to the local deviation of the grinding effect on the object to be ground, there is a concern that the object to be ground may have uneven thickness caused by grinding. For example, as the grinding time passes, the supplied grinding composition accumulates on the outer edge of the object to be ground, causing the local deviation of the grinding effect to become larger. That is, in the grinding process, the more time is spent on reducing defects, the more the tendency of uneven thickness increases. Therefore, for objects to be ground comprising a resin material, a higher grinding speed is required. Generally, it is known that the grinding removal speed of larger abrasive particles is higher. In addition, it is known that if the shape of the abrasive particles is deformed or the aspect ratio becomes higher, the grinding removal speed becomes higher. The present inventors have found that the deformation of the shape of these abrasive particles brings about a significantly higher grinding speed in the presence of a specific grinding accelerator, thereby reducing the uneven thickness of the object to be ground after grinding. In other words, by utilizing the grinding composition of the second mode, it is possible to grind with a significantly high grinding speed and reduce the local deviation of the grinding effect that may be produced when grinding, and it is possible to maintain or improve the flatness of the object to be ground. It has also been found in addition that by utilizing the grinding composition of the second mode, there are few scratches on the surface of the object to be ground after grinding. That is, by utilizing the grinding composition of the second mode, it is possible to reduce the defects on the surface of the object to be ground, and it is also possible to improve the surface quality of the object to be ground after grinding.

[0074] When the irregularity N of the silica particles is less than 1.5, the grinding removal rate of the resin material (polishing object) is reduced. The upper limit of the irregularity N of the silica particles is not particularly limited, but is practically 3.0 or less. The irregularity N of the silica particles is preferably 1.6 or more, more preferably 1.7 or more, further preferably 1.8 or more, and particularly preferably 1.9 or more.

[0075] The BET specific surface area SA of the silica particles used to calculate the degree of irregularity N is a specific surface area measured in accordance with JIS Z8830: 2013. More specifically, it can be measured by the method described in the Examples.

[0076] The theoretical specific surface area SA' of the silica particles is calculated by using the particle size at which the cumulative frequency from the smaller particle size side in the volume-based particle size distribution is 50% as D 50 The value of is calculated by the following formula (1).

[0077]

[0078] In the above formula (1), ρ is the density of silica particles, which is 1.80 to 2.20 g / cm 3 The density of the silica particles can be calculated, for example, by the method described in International Publication No. 2018 / 012176 (true density of silica).

[0079] Here, the D of the silica particles 50 The particle size at which the cumulative frequency from the smaller particle size side is 50% in the volume-based particle size distribution (the secondary particle size at which the cumulative frequency from the smaller particle size side is 50%). 50 As for the irregularity N, there is no particular limitation as long as it is 1.5 or more, but it is preferably 0.05 μm or more, more preferably 0.06 μm or more, further preferably 0.08 μm or more, particularly preferably 0.1 μm or more, and most preferably 0.15 μm or more. 50 It is preferably 1 μm or less, can be 0.8 μm or less, more preferably 0.5 μm or less, further preferably 0.3 μm or less, particularly preferably 0.25 μm or less, and most preferably 0.2 μm or less. According to one embodiment, the D of the silica particles is 50 50 nm or more and less than 200 nm. 50 When the amount falls within the above range, the improvement in the polishing removal rate of the resin material and the reduction in thickness unevenness of the polished object after polishing can be more effectively achieved.

[0080] The D of silica particles 10 The particle size at which the cumulative frequency from the smaller particle size side is 10% in the volume-based particle size distribution (the secondary particle size at which the cumulative frequency from the smaller particle size side is 10%). 10 As for the irregularity N, there is no particular limitation as long as it is 1.5 or more, but it is preferably 0.005 μm or more, more preferably 0.01 μm or more, further preferably 0.02 μm or more, particularly preferably 0.05 μm or more, and most preferably 0.07 μm or more. 10 It is preferably 0.5 μm or less, can be 0.3 μm or less, more preferably 0.25 μm or less, further preferably 0.2 μm or less, particularly preferably 0.15 μm or less, and most preferably 0.13 μm or less. 10 When the amount falls within the above range, the improvement in the polishing removal rate of the resin material and the reduction in thickness unevenness of the polished object after polishing can be more effectively achieved.

[0081] The D of silica particles 90The particle size at which the cumulative frequency from the smaller particle size side is 90% in the volume-based particle size distribution (the secondary particle size at which the cumulative frequency from the smaller particle size side is 90%). 90 As for the irregularity N, there is no particular limitation as long as it is 1.5 or more, but it is preferably 0.07 μm or more, more preferably 0.1 μm or more, further preferably 0.12 μm or more, particularly preferably 0.15 μm or more, and most preferably 0.2 μm or more. 90 The diameter of the silica particles is preferably 1.5 μm or less, can be 1.2 μm or less, more preferably 1.0 μm or less, further preferably 0.8 μm or less, particularly preferably 0.7 μm or less, and most preferably 0.5 μm or less. 90 When the amount falls within the above range, the improvement in the polishing removal rate of the resin material and the reduction in thickness unevenness of the polished object after polishing can be more effectively achieved.

[0082] The D of silica particles 90 Relative to D 10 The ratio (hereinafter referred to as "D 90 / D 10 ”) is preferably 1.2 or more, more preferably 1.5 or more, further preferably 1.8 or more, particularly preferably 2.0 or more, and most preferably 2.5 or more. 90 / D 10 It is preferably 6.5 or less, more preferably 6.0 or less, further preferably 5.0 or less, particularly preferably 4.0 or less, and most preferably 3.5 or less. 90 / D 10 When the amount falls within the above range, the improvement in the polishing removal rate of the resin material and the reduction in thickness unevenness of the polished object after polishing can be more effectively achieved.

[0083] According to one embodiment, in the polishing composition of the second embodiment, the particle size at which the cumulative frequency of the silica particles from the smaller particle size side is 10% in the volume-based particle size distribution is defined as D 10 The particle size at which the cumulative frequency of the silica particles is 90% from the smaller particle size side in the volume-based particle size distribution is defined as D 90 When the D 90 Relative to D 10 The ratio (D 90 / D 10 ) is 2.0 or above.

[0084] The D of silica particles 10 、D 50 , and D 90The particle size distribution of the particles can be determined by dynamic light scattering, laser diffraction, laser scattering, or pore resistance methods. In this specification, the values ​​determined based on the cumulative frequency from the smaller particle size side, the 10% particle size, the 50% particle size, and the 90% particle size in a volume-based particle size distribution measured using a laser diffraction particle size distribution analyzer are used. More specifically, the particle size distribution can be determined by the methods described in the Examples.

[0085] The shape of the silica particles is not particularly limited as long as the degree of irregularity N is 1.5 or greater. Examples of the shape of the silica particles include polyhedral prisms such as triangular prisms and quadrangular prisms, cylindrical shapes, straw bag shapes in which the center of a cylinder bulges out more than the ends, ring shapes with a through-center disk, plate shapes, a so-called cocoon shape with a constricted center, a so-called associated spherical shape formed by integrating multiple particles, a so-called konpeito shape having multiple protrusions on the surface, a rugby ball shape, a cone shape, a truncated cone shape, a pyramid shape, a truncated pyramid shape, a hemisphere shape, a needle shape, and an irregular shape.

[0086] The concentration (content) of the silicon dioxide granules in the grinding composition is not particularly limited, and relative to the gross mass of the grinding composition, is preferably more than 0.1 mass %, more preferably more than 0.5 mass %, further preferably more than 1 mass %, further more preferably more than 2 mass %, particularly preferably more than 5 mass %, most preferably more than 10 mass %. Along with the concentration of silicon dioxide granules becomes large, the grinding removal rate further improves, and the uneven thickness of the grinding object after grinding can be reduced. In addition, the concentration (content) of silicon dioxide granules is preferably less than 50 mass %, more preferably less than 40 mass %, further preferably less than 35 mass %, further more preferably less than 30 mass %, particularly preferably less than 25 mass %, most preferably less than 20 mass %. When being above-mentioned scope, the grinding removal rate of resin material can be further improved, the uneven thickness of the grinding object after grinding can be reduced. A preferred example of the concentration (content) of the silica particles is preferably 0.1% by mass or more and 50% by mass or less, more preferably 0.5% by mass or more and 40% by mass or less, further preferably 1% by mass or more and 35% by mass or less, further more preferably 2% by mass or more and 30% by mass or less, particularly preferably 5% by mass or more and 25% by mass or less, and most preferably 10% by mass or more and 20% by mass or less. The silica particles may be used alone or in combination of two or more. When two or more silica particles are used, the concentration (content) of the silica particles is the total amount.

[0087] As silica particles, colloidal silica is preferably used. As the manufacturing method of colloidal silica, sodium silicate method, sol-gel method etc. can be mentioned, and colloidal silica manufactured by any manufacturing method is all suitable for use. In order to make the anomaly N of silica particles (preferably colloidal silica) more than 1.5, it is possible to appropriately control by selecting the conditions (for example, reaction temperature, reaction concentration etc.) during the above-mentioned manufacturing. It should be noted that silica particles can use commercially available products. In this case, the silica particles used in the grinding composition of the second embodiment can be selected by measuring the anomaly N of silica particles.

[0088] In addition, regarding the D of silica particles 10 、D 50 and D 90 , can also be appropriately controlled by selecting the conditions during the production of the silica particles.

[0089] [Grinding accelerator]

[0090] The polishing composition of the second embodiment includes a polishing accelerator. The polishing accelerator is one or more selected from the group consisting of aluminum salts of monobasic acids, pyrrolidone compounds, and caprolactam compounds. The polishing accelerator assists polishing by the abrasive.

[0091] As the aluminum salt of a monoprotic acid, the aluminum salt of a monoprotic inorganic acid or a monoprotic organic acid can be enumerated. As the specific example of a monoprotic inorganic acid, nitric acid, hydrochloric acid, perchloric acid, nitrous acid, hypochlorous acid, hypophosphorous acid (phosphinic acid; H2PO(OH)), aminosulfonic acid etc. can be enumerated. As the specific example of a monoprotic organic acid, lactic acid, nicotinic acid, acetic acid, formic acid, propionic acid, valeric acid, hexanoic acid, caprylic acid, capric acid, cyclohexanecarboxylic acid, phenylacetic acid, benzoic acid, crotonic acid, methacrylic acid, methanesulfonic acid, ethanesulfonic acid, aminoethanesulfonic acid, benzenesulfonic acid, p-toluenesulfonic acid, 1-naphthalenesulfonic acid, 2-naphthalenesulfonic acid etc. can be enumerated. Their content is the content after removing the hydration water when the aluminum salt of a monoprotic acid has hydration water. It should be noted that, as the preferred example of the aluminum salt of a monoprotic acid, aluminum nitrate, aluminum chloride etc. can be enumerated.

[0092] The concentration (content) of the aluminum salt of the monoprotic acid in the grinding composition is not particularly limited, and relative to the gross mass of the grinding composition, is preferably more than 0.1 mass %, more preferably more than 0.5 mass %, further preferably more than 1 mass %, particularly preferably more than 2 mass %, particularly preferably more than 3 mass %, most preferably more than 5 mass %.Along with the concentration of the aluminum salt of the monoprotic acid becomes large, the grinding removal rate further improves, and the uneven thickness of the grinding object after grinding can be reduced.In addition, the concentration (content) of the aluminum salt of the monoprotic acid is preferably below 25 mass %, more preferably below 20 mass %, further preferably below 18 mass %, further more preferably below 15 mass %, particularly preferably below 12 mass %, most preferably below 10 mass %.When being above-mentioned scope, the grinding removal rate of resin material can be further improved, the uneven thickness of the grinding object after grinding can be reduced. A preferred example of the concentration (content) of the aluminum salt of the monobasic acid is preferably 0.1% by mass or more and 25% by mass or less, more preferably 0.5% by mass or more and 20% by mass or less, further preferably 1% by mass or more and 18% by mass or less, further more preferably 2% by mass or more and 15% by mass or less, particularly preferably 3% by mass or more and 12% by mass or less, and most preferably 5% by mass or more and 10% by mass or less, relative to the total mass of the polishing composition. The aluminum salt of the monobasic acid can be used alone or in combination of two or more. When two or more aluminum salts of the monobasic acid are used, the concentration (content) of the aluminum salt of the monobasic acid is the total amount.

[0093] Examples of the pyrrolidone compound include 2-pyrrolidone or 2-pyrrolidone derivatives, and polymers having a structural unit derived from a 2-pyrrolidone derivative. Examples of the 2-pyrrolidone derivative include 2-pyrrolidone, N-octyl-2-pyrrolidone, N-dodecyl-2-pyrrolidone, N-methyl-2-pyrrolidone, N-ethyl-2-pyrrolidone, N-cyclohexyl-2-pyrrolidone, N-hydroxyethyl-2-pyrrolidone, N-butyl-2-pyrrolidone, N-hexyl-2-pyrrolidone, N-decyl-2-pyrrolidone, N-octadecyl-2-pyrrolidone, N-hexadecyl-2-pyrrolidone, and N-vinyl-2-pyrrolidone. Examples of polymers having structural units derived from 2-pyrrolidone derivatives include homopolymers of N-vinyl-2-pyrrolidone (hereinafter also referred to as "polyvinyl pyrrolidone" or "PVP") or copolymers thereof. These pyrrolidone compounds may be used alone or in combination of two or more. Among these, polyvinyl pyrrolidone is preferred as the pyrrolidone compound.

[0094] The concentration (content) of the pyrrolidone compound in the grinding composition is not particularly limited. It is preferably 0.001% by mass or more, more preferably 0.003% by mass or more, further preferably 0.005% by mass or more, particularly preferably 0.007% by mass or more, particularly preferably 0.008% by mass or more, and most preferably 0.01% by mass or more relative to the gross mass of the grinding composition. As the concentration of the pyrrolidone compound increases, the grinding removal rate further improves, and the uneven thickness of the grinding object after grinding can be reduced. In addition, the concentration (content) of the pyrrolidone compound is preferably 3% by mass or less, more preferably 2% by mass or less, further preferably 1.5% by mass or less, further more preferably 1.2% by mass or less, particularly preferably 1% by mass or less, and most preferably 0.5% by mass or less relative to the gross mass of the grinding composition. When it is within the above range, the grinding removal rate of the resin material can be further improved, and the uneven thickness of the grinding object after grinding can be reduced. A preferred example of the concentration (content) of the pyrrolidone compound is preferably 0.001% by mass to 3% by mass, more preferably 0.003% by mass to 2% by mass, further preferably 0.005% by mass to 1.5% by mass, particularly preferably 0.007% by mass to 1.2% by mass, particularly preferably 0.008% by mass to 1% by mass, and most preferably 0.01% by mass to 0.5% by mass, relative to the total mass of the polishing composition. When two or more pyrrolidone compounds are used, the concentration (content) of the pyrrolidone compounds is expressed as a total amount.

[0095] In the polishing composition of the second embodiment, according to one embodiment, the pyrrolidone compound is polyvinyl pyrrolidone. In this case, the weight average molecular weight (Mw) of the polyvinyl pyrrolidone is preferably 2,000 or more, more preferably 3,000 or more, further preferably 5,000 or more, and particularly preferably 7,500 or more. In addition, the weight average molecular weight (Mw) of the polyvinyl pyrrolidone is preferably 900,000 or less, more preferably 500,000 or less, further preferably 250,000 or less, particularly preferably 100,000 or less, and most preferably 55,000 or less. As long as the weight average molecular weight of the polyvinyl pyrrolidone is within the above range, it is possible to more efficiently enhance the polishing removal rate of the resin material and reduce the uneven thickness of the polished object after polishing.

[0096] Examples of caprolactam compounds include ε-caprolactam or its derivatives, and polymers having structural units derived from ε-caprolactam or its derivatives. Caprolactam compounds can be used as a substitute for pyrrolidone compounds. Examples of caprolactam compounds include ε-caprolactam and nylon 6.

[0097] The concentration (content) of the caprolactam compound in the polishing composition is not particularly limited, but is preferably 0.01% by mass or more, more preferably 0.05% by mass or more, and even more preferably 0.1% by mass or more, relative to the total mass of the polishing composition. Furthermore, the concentration (content) of the caprolactam compound is preferably 5% by mass or less, more preferably 2% by mass or less, and even more preferably 1% by mass or less. When the content of the caprolactam compound is within the above range, it is possible to more efficiently enhance the polishing removal rate of the resin material and reduce uneven thickness of the polished object after polishing.

[0098] The pyrrolidone compound and the caprolactam compound may be commercially available products or may be synthesized by a known method.

[0099] According to one embodiment, in the polishing composition of the second embodiment, the polishing accelerator comprises an aluminum salt of a monobasic acid and a pyrrolidone compound. By including the aluminum salt of a monobasic acid and the pyrrolidone compound as polishing accelerators in the polishing composition of the second embodiment, the polishing removal rate of the resin material can be more effectively increased, and uneven thickness of the polished object can be reduced after polishing.

[0100] [water]

[0101] The polishing composition of the second embodiment contains water. Water disperses or dissolves the various components. From the perspective of preventing the polishing composition from being affected by impurities on other components, it is preferred to use water of the highest possible purity. Specifically, pure water, ultrapure water, or distilled water that has been filtered to remove foreign matter after removing impurity ions using an ion exchange resin is preferred. In addition, an organic solvent or the like may be included as a dispersion medium to control the dispersibility of other components in the polishing composition.

[0102] The main components contained in the polishing composition of the first embodiment and the polishing composition of the second embodiment are as described above. The following "other components" are common to the polishing composition of the first embodiment and the polishing composition of the second embodiment.

[0103] [Other ingredients]

[0104] The polishing composition of the present method may further contain known components such as pH adjusters, surfactants, dispersants, thickeners (viscosity regulators), surface protectants, wetting agents, water-soluble polymers (excluding polymers having a structural unit derived from 2-pyrrolidone), salts (excluding aluminum salts of monobasic acids), preservatives, and mildew-proof agents (hereinafter referred to as "other components") within the range that does not impair the effects of the present invention. The content of these other components can be appropriately set according to their addition purposes. Hereinafter, pH adjusters, surfactants, dispersants, thickeners (viscosity regulators), oxidizing agents, corrosion inhibitors, preservatives, mildew-proof agents, and chelating agents will be described.

[0105] <pH adjuster>

[0106] The polishing composition of the present method may further contain a pH adjuster. By selecting the type and addition amount of the pH adjuster, it can contribute to the adjustment of the pH of the polishing composition.

[0107] The pH adjuster is not particularly limited as long as it is a compound having a pH adjustment function, and known compounds can be used. The pH adjuster is not particularly limited as long as it has a pH adjustment function. For example, acids, bases, etc. can be cited.

[0108] As the acid, either an inorganic acid or an organic acid can be used. As the inorganic acid, there is no particular limitation. For example, sulfuric acid, nitric acid, hydrochloric acid, boric acid, carbonic acid, hypophosphorous acid, phosphorous acid, and phosphoric acid can be cited. As the organic acid, there is no particular limitation, and formic acid, acetic acid, propionic acid, butyric acid, valeric acid, 2-methylbutyric acid, n-hexanoic acid, 3,3-dimethylbutyric acid, 2-ethylbutyric acid, 4-methylvaleric acid, n-heptanoic acid, 2-methylhexanoic acid, n-octanoic acid, 2-ethylhexanoic acid, benzoic acid, glycolic acid, salicylic acid, glyceric acid, oxalic acid, malonic acid, succinic acid, glutaric acid, adipic acid, pimelic acid, maleic acid, phthalic acid, malic acid, tartaric acid, citric acid, and lactic acid, etc. carboxylic acids, as well as methanesulfonic acid, ethanesulfonic acid, and hydroxyethylsulfonic acid, etc. Among these, organic acids are preferred, and malic acid, citric acid, and maleic acid are more preferred. It should be noted that when using an inorganic acid, nitric acid, sulfuric acid, and phosphoric acid are preferred.

[0109] As the base, there is no particular limitation. For example, hydroxides of alkali metals, salts of alkali metals, hydroxides of alkaline earth metals, salts of alkaline earth metals, quaternary ammonium, ammonia, etc. can be cited.

[0110] Specific examples of alkali metals include potassium, sodium, etc. In addition, specific examples of alkaline earth metals include calcium, strontium, etc. Further, specific examples of salts include carbonates, bicarbonates, sulfates, acetates, etc. Further, specific examples of quaternary ammonium include tetramethylammonium, tetraethylammonium, tetrabutylammonium, and their hydroxides. Among these, as the base, potassium hydroxide or ammonia is preferred.

[0111] In addition, the pH adjuster may be used alone or in combination of two or more.

[0112] The pH of the polishing composition of this mode is not particularly limited, but is preferably 8 or less, more preferably 7 or less, further preferably 6 or less, particularly preferably 5 or less, and most preferably 4 or less. According to one embodiment, the pH of the polishing composition of this mode can be 3.5 or less, 3 or less, or less than 3. When the pH of the polishing composition is within the above range, the improvement of the polishing removal rate of the resin material and the reduction of the uneven thickness of the polishing object after polishing can be more efficiently exerted. In addition, the pH is preferably 1 or more, more preferably 1.5 or more. When citing an example, the pH of the polishing composition is preferably 1 or more and 8 or less, more preferably 1 or more and 7 or less, further preferably 1 or more and 6 or less, particularly preferably 1 or more and 5 or less, and most preferably 1 or more and 4 or less. According to one embodiment, the pH of the polishing composition is 1.0 to 6.0, 1.0 to 5.0, 1.5 to 4.5, 1.5 to 4.0, 2.0 to 5.0, 2.0 to 4.5, 2.0 to 4.0, or 1.0 to 3.5. The content of the pH adjuster is not particularly limited, but is preferably an amount that can adjust the pH to a value within the preferred range described above.

[0113] <Surfactant>

[0114] The polishing composition of some embodiments of the present invention may include a surfactant. The surfactant that may be included in the polishing composition of this embodiment is at least one selected from the group consisting of anionic surfactants, cationic surfactants, amphoteric surfactants, and nonionic surfactants. Among these, nonionic surfactants are preferred as the surfactant contained in the polishing composition. The surfactant may be used alone or in combination of two or more.

[0115] Examples of anionic surfactants include polyoxyethylene alkyl ether acetic acid, polyoxyethylene alkyl sulfate, alkyl sulfate, polyoxyethylene alkyl ether sulfuric acid, alkyl ether sulfuric acid, alkylbenzenesulfonic acid, alkyl phosphate, polyoxyethylene alkyl phosphate, polyoxyethylene sulfosuccinic acid, alkyl sulfosuccinic acid, alkylnaphthalenesulfonic acid, alkyl diphenyl ether disulfonic acid, and salts thereof.

[0116] Examples of the cationic surfactant include alkyltrimethylammonium salts, alkyldimethylammonium salts, alkylbenzyldimethylammonium salts, and alkylamine salts.

[0117] Examples of the amphoteric surfactant include alkyl betaine and alkylamine oxide.

[0118] Examples of the nonionic surfactant include polyoxyalkylene alkyl ethers such as polyoxyethylene alkyl ether, sorbitan fatty acid esters, glycerol fatty acid esters, polyoxyethylene fatty acid esters, polyoxyethylene alkylamines, and alkyl alkanolamides.

[0119] When the polishing composition includes a surfactant, the content of the surfactant is preferably 0.01% by mass or more, more preferably 0.1% by mass or more, relative to the gross mass of the polishing composition. Furthermore, the content of the surfactant in the polishing composition is preferably 3.0% by mass or less, more preferably 2.0% by mass or less, relative to the gross mass of the polishing composition. When the content of the surfactant is within the above-mentioned range, the uniformity of the polishing of the object to be polished is further improved.

[0120] <Dispersant / Thickener (Viscosity Modifier)>

[0121] The polishing composition of this mode may include a dispersant or a thickener (viscosity modifier). The dispersant or thickener plays the role of uniformly dispersing the abrasive particles (silicon dioxide particles) in the liquid, thereby allowing the abrasive particles to act efficiently on the polishing object. In addition, the dispersant or thickener is present between the abrasive particles, thereby also being able to expect the effect of suppressing the agglomeration of the abrasive particles, thereby suppressing the generation of scratches caused by the aggregated abrasive particles.

[0122] Specific examples of dispersants include colloidal substances containing fine particles, such as colloidal alumina, colloidal zirconia, colloidal titania, alumina sol, zirconia sol, titania sol, fumed alumina, fumed zirconia, and fumed titania. Furthermore, sodium phosphate, sodium hexametaphosphate, and sodium pyrophosphate, which are commonly used dispersants, may also be used.

[0123] Specific examples of thickeners include glycols and polymers such as propylene glycol polymers and ethylene glycol polymers. More specifically, glycols include propylene glycol, ethylene glycol, dipropylene glycol, polypropylene glycol, diethylene glycol, and polyethylene glycol. Polymers include sodium polyacrylate, polyvinyl alcohol, and hydroxyethyl cellulose.

[0124] [Grinding removal rate]

[0125] The polishing composition of this embodiment can increase the polishing removal rate of resin materials. In one example, the polishing removal rate of the resin material is preferably 140 nm / min or greater, more preferably 150 nm / min or greater, and even more preferably 170 nm / min or greater. It should be noted that the polishing removal rate can be measured by the method described in the Examples.

[0126] [Uneven thickness]

[0127] The grinding composition of this mode can maintain or improve the flatness of the object to be polished. That is, the grinding composition of this mode can reduce the uneven thickness of the object to be polished that may be produced due to grinding. Uneven thickness can be evaluated with GBIR. When giving an example, the uneven thickness of the object to be polished (the object to be polished after grinding) after grinding based on the grinding composition of this mode is preferably less than 2.0 μm, more preferably less than 1.5 μm, more preferably less than 1.2 μm, particularly preferably less than 0.8 μm. Therefore, in one embodiment, using the grinding composition of this mode, the flatness defined by GBIR of the object to be polished after grinding can be less than 2.0 μm (preferably less than 1.5 μm, more preferably less than 1.2 μm, more preferably less than 0.8 μm). It should be noted that GBIR can be measured by the method described in the examples.

[0128] [Surface roughness (Rms)]

[0129] The grinding composition of this mode can maintain or improve the surface roughness of the object to be ground. That is, the grinding composition of this mode can reduce the surface roughness of the object to be ground that may be produced due to grinding. The surface roughness of the object to be ground can be evaluated by evaluating the parameter, root mean square height (Rms) of the deviation of the concave-convex relative to the reference surface. When citing an example, the root mean square height (Rms) of the object to be ground (the object to be ground after grinding) based on the grinding composition of this mode is preferably less than 1.5nm, more preferably 1.2nm, further preferably below 1.0nm, particularly preferably below 0.8nm, most preferably below 0.5nm. The lower limit of the surface roughness defined by the root mean square height (Rms) of the object to be ground is not particularly limited, and is practical for example more than 0.01nm. Therefore, in one embodiment, utilizing the grinding composition of this mode, the surface roughness defined by the root mean square height (Rms) of the object to be ground can be below 1.0nm (preferably below 0.5nm). It should be noted that the root mean square height (Rms) can be measured by the method described in the Examples.

[0130] [Method for producing polishing composition]

[0131] In the polishing composition of this embodiment, the manufacturing method (preparation method) of the polishing composition is not particularly limited. For example, a manufacturing method comprising stirring and mixing silica particles, a polishing accelerator (one or more selected from the group consisting of an aluminum salt of a monobasic acid, a pyrrolidone compound, and a caprolactam compound), and other necessary ingredients can be preferably adopted. It should be noted that the silica particles, water, polishing accelerator, and other ingredients are the same as those described above, and therefore, description thereof is omitted here.

[0132] The temperature for mixing the components of the polishing composition is not particularly limited, but is preferably 10° C. to 40° C., and may be heated to increase the dissolution rate. The mixing time is also not particularly limited.

[0133] [Grinding method]

[0134] Another aspect of the present invention relates to a lapping method comprising the step of lapping an object to be lapped comprising a resin material using the lapping composition. The lapping step is not limited to being performed after the polishing step, but may also be performed after the cutting step or the grinding step. Preferred examples of the object to be lapped in the lapping method of this embodiment are the same as those given in the description of [object to be lapped].

[0135] The third aspect of the present invention is a polishing method for polishing an object made of a resin material using the polishing composition of the first aspect. Therefore, the third aspect of the present invention provides a polishing method comprising the step of supplying a polishing composition between the object made of a resin material and a polishing pad to polish the object, wherein the polishing composition contains silica particles and water, and the average particle size D of the silica particles is 0.0447 W / cm2. 50 It is 50nm or more.

[0136] A fourth aspect of the present invention is a polishing method for polishing an object to be polished comprising a resin material using the polishing composition of the second aspect. Therefore, the fourth aspect of the present invention can provide a polishing method comprising the step of supplying a polishing composition between the object to be polished comprising a resin material and a polishing pad to polish the object to be polished, wherein the polishing composition contains silica particles, a polishing accelerator, and water, wherein the polishing accelerator is one or more selected from the group consisting of aluminum salts of monobasic acids, pyrrolidone compounds, and caprolactam compounds, and wherein the silica particles have a particle size at which the cumulative frequency from the smaller particle size side in a volume-based particle size distribution is 50% as D. 50 , the BET specific surface area is set as SA, and the D 50 When the calculated theoretical specific surface area is SA', the irregularity N represented by irregularity N=SA / SA' is 1.5 or more.

[0137] In the grinding method of this mode, when the object to be ground is ground with a grinding composition, the device and conditions used in common grinding can be used to carry out. As common grinding devices, single-sided grinding devices and double-sided grinding devices can be cited. For single-sided grinding devices, the object to be ground is usually kept with a holder called a carrier, while the grinding composition is supplied from above, while a flat plate with a grinding pad is pressed against the single side of the object to be ground and the flat plate is rotated, thereby grinding the single side of the object to be ground. For double-sided grinding devices, the object to be ground is usually kept with a holder called a carrier, while the grinding composition is supplied from above, while a flat plate with a grinding pad is pressed against the opposite side of the object to be ground, and they are rotated in relative directions, thereby grinding the two sides of the object to be ground. At this time, the physical action brought by the friction between the grinding pad and the grinding composition and the object to be ground and the chemical action brought to the object to be ground by the grinding composition are ground. As grinding pads, porous bodies such as non-woven pads, polyurethane pads, suede pads can be used without particular limitation. The polishing pad is preferably processed so as to allow the polishing liquid to accumulate.

[0138] As the grinding conditions of the lapping method of this mode, for example, the flow rate of grinding load, plate speed, carrier speed, grinding composition, grinding time etc. can be enumerated.These grinding conditions are not particularly limited, for example, for grinding load, the per unit area of ​​the preferred grinding object is more than 0.1psi (0.69kPa) and below 10psi (69kPa), more preferably more than 0.5psi (3.5kPa) and below 5.0psi (35kPa). Usually the higher the load, the higher the friction based on abrasive grain, because the machining force improves, so the grinding removal rate rises. When being this scope, can bring into play sufficient grinding removal rate, can suppress the breakage of the grinding object caused by load, suppress the defectives such as surface generation scratches. As long as the feed rate of grinding composition is the feed rate (flow rate) that covers the entire grinding object, can be adjusted according to conditions such as the size of the grinding object. The method for supplying grinding composition to the grinding pad is not particularly limited either, for example, can adopt the method utilizing pump etc. to carry out continuous supply. The processing time is not particularly limited as long as it is a time that can obtain a desired processing result, but a shorter time is preferably used due to a higher polishing removal rate.

[0139] Here, the surface of the grinding object is usually finished into a flat face with few uneven thickness and a smooth face with few defects through a grinding process and a grinding process. As a grinding process, comprise more than one grinding process selected from the group consisting of a rough grinding process (pre-grinding process), an intermediate grinding process (moderate grinding process) and fine grinding (finishing grinding process). That is, the grinding process can be composed of a plurality of grinding processes. The grinding method using the present mode of the above-mentioned grinding composition is suitable for intermediate grinding process and fine grinding process, can be particularly suitable for fine grinding process. The grinding method of this mode (that is, fine grinding) for example can be implemented after the rough grinding process and the intermediate grinding process, can also omit the intermediate grinding process, and implement after the rough grinding process.

[0140] The polishing characteristics required for each of the rough polishing, intermediate polishing, and fine polishing steps differ. Therefore, depending on the stage of the polishing process (i.e., rough polishing, intermediate polishing, or fine polishing), the composition of the polishing composition (e.g., the type of abrasive, the particle size of the abrasive, the type of components, the content of the components, etc.), and polishing conditions (e.g., the polishing pad, polishing pressure, the amount (flow rate) of the polishing composition used), etc., may vary.

[0141] In one embodiment, in the rough polishing step, from the perspective of reducing thickness unevenness, the object to be polished is preferably polished using a double-sided polishing apparatus that simultaneously polishes both sides of the substrate. Furthermore, in one embodiment, in the rough polishing step, from the perspective of reducing thickness unevenness, the polishing pad is preferably a non-woven fabric pad, a polyurethane pad, or a suede pad, with a non-woven fabric pad and a polyurethane pad being particularly preferred, and a polyurethane pad being most preferred.

[0142] According to one embodiment, for the polishing load in the rough polishing process, the polishing load per unit area of ​​the object to be polished is preferably 0.1 psi (0.69 kPa) or more and 10 psi (69 kPa) or less, more preferably 0.5 psi (3.5 kPa) or more and 5.0 psi (35 kPa) or less. According to one embodiment, the supply rate of the polishing composition in the rough polishing process (also referred to as the flow rate or slurry flow rate of the polishing composition) is not particularly limited, for example, preferably 1 (mL / min) or more and 300 (mL / min) or less, 1 (mL / min) or more and 200 (mL / min) or less, 1 (mL / min) or more and 150 (mL / min) or less, 1 (mL / min) or more and 100 (mL / min) or less, or 1 (mL / min) or more and 50 (mL / min) or less.

[0143] In one embodiment, in the rough grinding process, the Shore A hardness of the grinding pad is preferably 98° or less, more preferably 95° or less. The lower limit of the Shore A hardness of the grinding pad in the rough grinding process is preferably 60° or more, more preferably 70° or more, and further preferably 80° or more. According to one embodiment, it can be 60° or more and 98° or less, or 70° or more and 98° or less, 70° or more and 95° or less, 80° or more and 98° or less, or 80° or more and 95° or less. By making the Shore A hardness of the grinding pad used in the rough grinding process within the above range, the grinding pad and the object to be ground are in contact with each other with appropriate pressure, further exerting the effect of improving the grinding removal rate of the resin material and reducing the uneven thickness of the object to be ground after grinding. It should be noted that the Shore A hardness of the grinding pad is a value measured based on a type A durometer according to JIS K 6253-3:2012.

[0144] According to one embodiment, in the manufacturing method of this embodiment, the object to be polished may be polished using a polishing composition containing aluminum oxide particles as abrasive particles in the rough polishing step. In this case, the average primary particle size D of the aluminum oxide particles is 50 It is preferably 0.1 μm or more and 5.0 μm or less.

[0145] According to one embodiment, the rough grinding process can obtain a polished object having a thickness of preferably 0.10 mm or more and 0.80 mm or less, more preferably 0.10 mm or more and 0.60 mm or less, and further preferably 0.10 mm or more and 0.55 mm or less (roughly ground polished object). In addition, according to one embodiment, the rough grinding process can obtain a polished object having a GBIR of preferably 1.5 μm or less, more preferably 1.0 μm or less, and further preferably less than 0.5 μm (roughly ground polished object). According to one embodiment, the rough grinding process can obtain a polished object having a surface with defects having a depth of more than 100 nm.

[0146] In one embodiment, an intermediate step is performed after the roughing step. In the intermediate grinding step, from the perspective of reducing thickness unevenness, the object to be ground is preferably ground using a double-sided grinding device that grinds both sides of the substrate simultaneously. In one embodiment, in the intermediate grinding step, the grinding pad is preferably a non-woven pad, a polyurethane pad, or a suede pad, particularly preferably a non-woven pad or a polyurethane pad, and most preferably a polyurethane pad, from the perspective of reducing thickness unevenness.

[0147] According to one embodiment, the polishing load in the intermediate polishing step is preferably 0.1 psi (0.69 kPa) or more and 10 psi (69 kPa) or less per unit area of ​​the polishing object, more preferably 0.5 psi (3.5 kPa) or more and 5.0 psi (35 kPa) or less. According to one embodiment, the supply rate of the polishing composition in the intermediate polishing step is preferably, for example, 1 (mL / min) or more and 300 (mL / min) or less, 1 (mL / min) or more and 200 (mL / min) or less, 1 (mL / min) or more and 150 (mL / min) or less, 1 (mL / min) or more and 100 (mL / min) or less, or 1 (mL / min) or more and 50 (mL / min) or less.

[0148] According to one embodiment, in the production method of this aspect, the object to be polished may be polished with the polishing composition in the intermediate polishing step.

[0149] In one embodiment, in the intermediate grinding process, the Shore A hardness of the polishing pad is preferably 90° or less, more preferably 85° or less, further preferably 82° or less, even more preferably 80° or less, particularly preferably 78° or less, and most preferably 75° or less. The lower limit of the Shore A hardness of the polishing pad in the intermediate grinding process is preferably 10° or more, more preferably 20° or more, further preferably 30° or more, particularly preferably 40° or more, and most preferably 50° or more. According to one embodiment, it can be 60° or more and 80° or less, or 65° or more and 80° or less, or 68° or more and 80° or less. By making the Shore A hardness of the polishing pad used in the intermediate grinding process within the above range, the polishing pad and the polishing object contact each other with appropriate pressure, further exerting the effect of improving the polishing removal rate of the resin material and reducing the uneven thickness of the polishing object after grinding. It should be noted that the Shore A hardness of the polishing pad is a value measured based on a type A durometer in accordance with JIS K 6253-3:2012.

[0150] According to one embodiment, by the intermediate grinding process, the grinding object (grinding object after intermediate grinding) with a thickness of preferably more than 0.10mm and less than 0.80mm, more preferably more than 0.10mm and less than 0.60mm, further preferably more than 0.10mm and less than 0.55mm can be obtained. In addition, according to one embodiment, by the intermediate grinding process, the grinding object (grinding object after intermediate grinding) with a GBIR preferably less than 1.5μm, more preferably less than 1.0μm, further preferably less than 0.5μm can be obtained. According to one embodiment, by the intermediate grinding process, the grinding object (grinding object after intermediate grinding) with a surface having a defect of less than 70nm in depth can be obtained. That is, using the grinding method of this mode, the defects of the grinding object can be reduced, and the grinding object (grinding object after grinding) in which the scratches less than 100nm in depth are also reduced can be obtained.

[0151] After the rough grinding step, or the rough grinding step and the intermediate grinding step, a fine grinding step is performed using the polishing composition, thereby obtaining a polished object in which the resin material is ground at high speed and thickness unevenness is suppressed. Therefore, according to one embodiment, according to the manufacturing method of this mode, the polished object comprising the resin material undergoes the rough grinding step, or the rough grinding step and the intermediate grinding step.

[0152] In one embodiment, in the fine polishing step, from the perspective of reducing thickness unevenness, the object to be polished is preferably polished using a double-side polishing device that simultaneously polishes both sides of the substrate. Furthermore, in one embodiment, in the fine polishing step, a polyurethane pad or a suede pad is preferably used as the polishing pad, and a suede pad is more preferably used.

[0153] In one embodiment, in the fine grinding process, the Shore A hardness of the grinding pad is preferably 90° or less, more preferably 85° or less, further preferably 82° or less, further preferably 80° or less, particularly preferably 78° or less, and most preferably 75° or less. The lower limit of the Shore A hardness of the grinding pad is preferably 10° or more, more preferably 20° or more, further preferably 30° or more, particularly preferably 40° or more, particularly more preferably 45° or more, and most preferably 50° or more. According to one embodiment, it can be 45° or more and 80° or less, 50° or more and 80° or less, 60° or more and 80° or less, 65° or more and 80° or less, or 68° or more and 80° or less. By making the Shore A hardness of the grinding pad used in the fine grinding process within the above range, the grinding pad and the object to be ground contact each other with appropriate pressure, the improvement of the grinding removal rate of the resin material and the reduction effect of the uneven thickness of the object to be ground after grinding can be further exerted.

[0154] According to one embodiment, for the grinding load in the fine grinding process, the per unit area of ​​the preferred grinding object is 0.1psi (0.69kPa) or more and 10psi (69kPa) or less, more preferably 0.5psi (3.5kPa) or more and 5.0psi (35kPa) or less. According to one embodiment, the supply of the grinding composition in the fine grinding process is preferably 1 (mL / min) or more and 50 (mL / min) or less, more preferably 3 (mL / min) or more and 45 (mL / min) or less, further preferably 5 (mL / min) or more and 40 (mL / min) or less, particularly preferably 8 (mL / min) or more and 30 (mL / min) or less. When the supply of the grinding composition in the fine grinding process is within the above range, it is possible to reduce uneven thickness. The less uneven thickness of the grinding composition is, the more it is improved. In addition, it is also possible to reduce costs from the aspect of the usage amount of the grinding composition, which is preferred.

[0155] According to one embodiment, by a fine grinding process, a grinding object (grinding object after fine grinding) having a thickness of, for example, more than 0.10 mm and less than 0.90 mm, preferably more than 0.10 mm and less than 0.80 mm, more preferably more than 0.10 mm and less than 0.60 mm, further preferably more than 0.10 mm and less than 0.55 mm can be obtained. In addition, according to one embodiment, by a fine grinding process, a grinding object (grinding object after fine grinding) having a GBIR preferably less than 1.5 μm, more preferably less than 1.0 μm, further preferably less than 0.5 μm can be obtained. According to one embodiment, by a fine grinding process, a grinding object (grinding object after fine grinding) having a surface with a defect of less than 70 nm in depth can be obtained. That is, by the grinding method of this embodiment, the defects of the grinding object can be reduced, and a grinding object (grinding object after grinding) having completed grinding in which scratches less than 100 nm in depth are also reduced can be obtained.

[0156] In addition, another embodiment of the present invention relates to a method for manufacturing a polished object having been polished, comprising the step of polishing the object using the polishing method described above. Preferred examples of the polished object of this embodiment are the same as those described in the description of the polished object. As a preferred example, a method for manufacturing an optical component can be cited, comprising the step of polishing an optical resin material using the polishing method described above.

[0157] [Grinding system]

[0158] Another aspect of the present invention relates to a polishing system including the polishing composition described above, an object to be polished made of a resin material, and a polishing pad.

[0159] The fifth aspect of the present invention is a polishing system comprising: the polishing composition of the first aspect, an object to be polished comprising a resin material, and a polishing pad. Therefore, the fifth aspect of the present invention can provide a polishing system comprising: an object to be polished comprising a resin material, a polishing pad, and a polishing composition, wherein the polishing composition contains silica particles and water; the average particle size D of the silica particles is 50 The surface of the polishing object is in contact with the polishing pad and the polishing composition.

[0160] The sixth aspect of the present invention is a polishing system comprising: the polishing composition of the second aspect, an object to be polished comprising a resin material, and a polishing pad. Therefore, the sixth aspect of the present invention can provide the following polishing system comprising: an object to be polished comprising a resin material, a polishing pad, and a polishing composition, wherein the polishing composition contains silica particles, a polishing accelerator, and water; the polishing accelerator is one or more selected from the group consisting of aluminum salts of monobasic acids, pyrrolidone compounds, and caprolactam compounds; and the silica particles have a particle size at which the cumulative frequency from the smaller particle size side in a volume-based particle size distribution is 50% as D. 50 , the BET specific surface area is set as SA, and the D 50 When the calculated theoretical specific surface area is SA', the irregularity N represented by irregularity N=SA / SA' is 1.5 or more; and the surface of the polishing object is brought into contact with the polishing pad and the polishing composition.

[0161] Preferred embodiments of the polishing object and the polishing composition applicable to the polishing system of this embodiment are the same as those described above, and therefore description thereof will be omitted.

[0162] The polishing system of this method can make both sides of the polishing object contact with the polishing pad and the polishing composition to polish both sides of the polishing object at the same time, or can make only one side of the polishing object contact with the polishing pad and the polishing composition to polish only one side of the polishing object.

[0163] In the grinding system of this mode, a working slurry comprising the above-mentioned grinding composition is prepared. Then, the grinding composition is supplied to the object to be ground and ground by a conventional method. For example, the object to be ground is arranged on a common grinding device, and the grinding composition is supplied to the surface (grinding object face) of the object to be ground by the grinding pad of the grinding device. Typically, while the above-mentioned grinding composition is continuously supplied, the grinding pad is pressed against the surface of the object to be ground and the two are moved relative to each other (for example, rotationally moved). Through the grinding process, the grinding of the object to be ground is completed.

[0164] The polishing pad used in the polishing system of this embodiment can be a nonwoven pad, a polyurethane pad, or a suede pad. Among these, the polishing pad is preferably a polyurethane pad or a suede pad, and is more preferably a suede pad from the viewpoint of further reducing defects.

[0165] In the polishing system of this embodiment, the pressure during contact with the polishing pad and the polishing composition, i.e., the polishing load, is preferably 0.1 psi (0.69 kPa) or more and 10 psi (69 kPa) or less per unit area of ​​the polishing object, more preferably 0.5 psi (3.5 kPa) or more and 5.0 psi (35 kPa) or less. According to one embodiment, in the polishing system of this embodiment, the supply rate of the polishing composition is preferably 1 (mL / min) or more and 50 (mL / min) or less, more preferably 3 (mL / min) or more and 45 (mL / min) or less, further preferably 5 (mL / min) or more and 40 (mL / min) or less, and particularly preferably 8 (mL / min) or more and 30 (mL / min) or less.

[0166] In the grinding system of this mode, according to one embodiment, the Shore A hardness of the grinding pad is preferably 90° or less, more preferably 85° or less, further preferably 82° or less, even more preferably 80° or less, particularly preferably 78° or less, and most preferably 75° or less. The lower limit of the Shore A hardness of the grinding pad is preferably 10° or more, more preferably 20° or more, further preferably 30° or more, particularly preferably 40° or more, particularly more preferably 45° or more, and most preferably 50° or more. According to one embodiment, it can be 45° or more and 80° or less, 50° or more and 80° or less, 60° or more and 80° or less, 65° or more and 80° or less, or 68° or more and 80° or less. In the grinding system of this mode, by making the Shore A hardness of the grinding pad within the above range, the grinding pad and the grinding object contact each other with appropriate pressure, further exerting the effect of improving the grinding removal rate of the resin material and reducing the uneven thickness of the grinding object after grinding.

[0167] While the embodiments of the present invention have been described in detail, this is for illustrative and exemplary purposes only and is not intended to be restrictive. It should be understood that the scope of the present invention should be interpreted in accordance with the appended claims.

[0168] In addition, the present invention includes the following aspects and configurations:

[0169] [1] A polishing composition for polishing an object to be polished made of a resin material, the polishing composition containing silica particles and water, wherein the average particle size D of the silica particles is 50 More than 50nm;

[0170] [2] The polishing composition according to [1] above, further comprising a polishing accelerator,

[0171] The polishing accelerator is one or more selected from the group consisting of aluminum salts of monobasic acids, pyrrolidone compounds, and caprolactam compounds;

[0172] [3] The polishing composition according to [1] or [2], wherein the silica particles have a particle size at which the cumulative frequency from the smaller particle size side in the volume-based particle size distribution is 50% as D 50 , the BET specific surface area is set as SA, and the D 50 When the calculated theoretical specific surface area is SA', the irregularity N represented by irregularity N = SA / SA' is 1.2 or more;

[0173] [4] The polishing composition according to any one of [1] to [3] above, wherein the average particle size D of the silica particles is 50 50 nm or more and less than 200 nm;

[0174] [5] The polishing composition according to any one of [1] to [4] above, wherein the polishing accelerator comprises the aluminum salt of the monobasic acid and the pyrrolidone compound;

[0175] [6] The polishing composition according to any one of [1] to [5] above, wherein the silica particles have a particle size at which the cumulative frequency from the smaller particle size side is 10% in the volume-based particle size distribution of the silica particles, D 10 The particle size at which the cumulative frequency of the silica particles is 90% from the smaller particle size side in the volume-based particle size distribution is defined as D 90 When D 90 Relative to D 10 The ratio (D 90 / D 10 ) is 2.0 or above;

[0176] [7] The polishing composition according to any one of [1] to [6] above, wherein the resin material is an optical resin material;

[0177] [8] The polishing composition according to any one of [1] to [7] above, wherein the average thickness of the object to be polished before polishing is 1 mm or less;

[0178] [9] The polishing composition according to any one of [1] to [8] above, wherein the flatness of the polishing object after polishing as defined by GBIR is 1.5 μm or less;

[0179]

[10] A polishing composition for polishing an object to be polished comprising a resin material, the polishing composition comprising silica particles, a polishing accelerator, and water, wherein the polishing accelerator is one or more selected from the group consisting of an aluminum salt of a monobasic acid, a pyrrolidone compound, and a caprolactam compound, wherein the silica particles have a particle size at which the cumulative frequency from the smaller particle size side in the volume-based particle size distribution of the silica particles is 50% and is defined as D 50 , the BET specific surface area is set as SA, and the D 50 When the calculated theoretical specific surface area is SA', the irregularity N represented by irregularity N = SA / SA' is 1.5 or more;

[0180]

[11] A polishing method comprising the step of polishing an object to be polished comprising a resin material using the polishing composition described in any one of [1] to

[10] above;

[0181]

[12] A method for manufacturing an optical component, comprising the step of polishing an optical resin material using the polishing method described in

[11] above;

[0182]

[13] A polishing method comprising the steps of supplying a polishing composition between an object to be polished comprising a resin material and a polishing pad to polish the object to be polished, wherein the polishing composition contains silica particles and water, and the average particle size D of the silica particles is 50 More than 50nm;

[0183]

[14] The polishing method according to

[13] , wherein the Shore A hardness of the polishing pad is 40 or greater;

[0184]

[15] The polishing method according to

[13] or

[14] , wherein the polishing composition further comprises a polishing accelerator, wherein the polishing accelerator is one or more selected from the group consisting of aluminum salts of monobasic acids, pyrrolidone compounds, and caprolactam compounds;

[0185]

[16] The polishing method according to any one of

[13] to

[15] , wherein, for the silica particles, the particle size at which the cumulative frequency from the smaller particle size side is 50% in the volume-based particle size distribution is defined as D 50 , the BET specific surface area is set as SA, and the D 50 When the calculated theoretical specific surface area is SA', the irregularity N represented by irregularity N = SA / SA' is 1.2 or more;

[0186]

[17] The grinding method according to any one of

[13] to

[16] , wherein the average particle size D of the silica particles is 50 50 nm or more and less than 200 nm;

[0187]

[18] The polishing method according to any one of

[13] to

[17] above, wherein the flatness of the polishing object after polishing as defined by GBIR is 1.5 μm or less;

[0188]

[19] A polishing system comprising: a polishing object made of a resin material, a polishing pad, and a polishing composition, wherein the polishing composition contains silica particles and water, and the average particle size D of the silica particles is 50 The surface of the polishing object is brought into contact with the polishing pad and the polishing composition;

[0189]

[20] A polishing system comprising: a polishing object made of a resin material, a polishing pad, and a polishing composition, wherein the polishing composition contains silica particles, a polishing accelerator, and water.

[0190] The polishing accelerator is one or more selected from the group consisting of aluminum salts of monobasic acids, pyrrolidone compounds, and caprolactam compounds; and the silica particles are sized such that the cumulative frequency of the silica particles from the smaller particle size side is 50% in the volume-based particle size distribution of the silica particles is defined as D. 50 , the BET specific surface area is set as SA, and the D 50 When the calculated theoretical specific surface area is SA', the irregularity N represented by irregularity N = SA / SA' is 1.5 or more; the surface of the polishing object is brought into contact with the polishing pad and the polishing composition;

[0191]

[21] The polishing system according to

[19] or

[20] above, wherein the Shore A hardness of the polishing pad is 40 or greater.

[0192] In addition, the present invention includes the following aspects and configurations:

[0193] [1] A polishing composition for polishing an object to be polished made of a resin material, the polishing composition comprising silica particles, a polishing accelerator, and water, wherein the polishing accelerator is one or more selected from the group consisting of an aluminum salt of a monobasic acid, a pyrrolidone compound, and a caprolactam compound, wherein the silica particles have a particle size at which the cumulative frequency of the particle size distribution of the silica particles on a volume basis from the smaller particle size side is 50%, and the particle size D is the particle size at which the cumulative frequency of the particle size distribution of the silica particles on the smaller particle size side is 50%. 50 , the BET specific surface area is set as SA, and the D 50 When the calculated theoretical specific surface area is SA', the irregularity N represented by irregularity N = SA / SA' is 1.5 or more;

[0194] [2] The polishing composition according to [1] above, wherein the polishing accelerator comprises the aluminum salt of the monobasic acid and the pyrrolidone compound;

[0195] [3] The polishing composition according to [1] or [2], wherein the silica particles have a particle size at which the cumulative frequency from the smaller particle size side is 10% in the volume-based particle size distribution of the silica particles, and the particle size at which the cumulative frequency from the smaller particle size side is 10% is defined as D. 10 The particle size at which the cumulative frequency of the silica particles is 90% from the smaller particle size side in the volume-based particle size distribution is defined as D 90 When D 90 Relative to D 10 The ratio (D 90 / D 10 ) is 2.0 or above;

[0196] [4] The polishing composition according to any one of [1] to [3] above, wherein the resin material is an optical resin material;

[0197] [5] The polishing composition according to any one of [1] to [4] above, wherein the average thickness of the object to be polished before polishing is 1 mm or less;

[0198] [6] The polishing composition according to any one of [1] to [5] above, wherein the flatness of the polishing object after polishing as defined by GBIR is 1.5 μm or less;

[0199] [7] A polishing method comprising: polishing an object to be polished comprising a resin material using the polishing composition described in any one of [1] to [6] above;

[0200] [8] A method for manufacturing an optical component, comprising the step of polishing an optical resin material using the polishing method described in [7] above;

[0201] [9] A polishing system comprising: a polishing object comprising a resin material, a polishing pad, and a polishing composition, wherein the polishing composition contains silica particles, a polishing accelerator, and water; the polishing accelerator is one or more selected from the group consisting of aluminum salts of monobasic acids, pyrrolidone compounds, and caprolactam compounds; and the silica particles have a particle size at which the cumulative frequency from the smaller particle size side in a volume-based particle size distribution is 50% as D. 50 , the BET specific surface area is set as SA, and the D 50 When the calculated theoretical specific surface area is SA', the irregularity N represented by irregularity N = SA / SA' is 1.5 or more; the surface of the polishing object is brought into contact with the polishing pad and the polishing composition;

[0202]

[10] The polishing system according to [9] above, wherein the polishing pad is a suede pad.

[0203] [Example]

[0204] The present invention will be described with reference to the following examples. However, the technical scope of the present invention is not limited to the following examples. It should be noted that, unless otherwise specified, "%" and "parts" refer to "mass %" and "mass parts" respectively.

[0205] (Preparation of Polishing Compositions of Examples 1 to 17 and Comparative Examples 1 and 2)

[0206] The colloidal silica in the amount described in Table 1 and the remaining amount of water when the total mass of the composition is 100 were mixed to prepare the polishing compositions of Examples 1 to 3 and Comparative Example 1 (mixing temperature: about 25°C, mixing time: about 30 minutes). The colloidal silica in the amount described in Table 2, the polishing accelerator in the amount described in Table 2, and the remaining amount of water when the total mass of the composition is 100 were mixed to prepare the polishing compositions of Examples 4 to 17 and Comparative Example 2 (mixing temperature: about 25°C, mixing time: about 30 minutes). It should be noted that the polishing accelerator was 8% by mass when aluminum nitrate was contained and 0.01% by mass when polyvinyl pyrrolidone was contained. The weight average molecular weight of polyvinyl pyrrolidone was 45,000.

[0207] The volume-based average primary particle size of the silica particles used as the abrasive and the pH of each polishing composition are shown in Tables 1 and 2. In Tables 1 and 2, “-” indicates that the component is not contained.

[0208] The physical properties of the silica particles of the polishing composition obtained above were evaluated, and the polishing removal rate of the polishing object (episulfide resin substrate) and the scratches on the polishing object surface (thiourethane resin substrate surface) were evaluated according to the methods described below.

[0209] [evaluate]

[0210] <D of silica particles 10 、D 50 、D 90 >

[0211] The silica particles were measured using a laser diffraction particle size distribution analyzer (Microtrac BEL Corp., Microtrac Particle Size Distribution Analyzer MT3300EX II) to determine the volume-based particle size distribution. The particle size at which the cumulative frequency from the smaller particle size side reached 10% in the obtained particle size distribution was defined as the D of the silica particles. 10 The particle size at which the cumulative frequency from the smaller particle size side is 50% is defined as the D of the silica particles. 50 The particle size at which the cumulative frequency from the smaller particle size side is 90% is defined as the D of the silica particles. 90 .

[0212] <BET specific surface area SA of silica particles>

[0213] The BET specific surface area SA of the silica particles was measured using a fully automatic specific surface area measuring apparatus manufactured by Mountech Co., Ltd. (Macsorb (registered trademark) HM model-1201).

[0214] <Theoretical Specific Surface Area SA' of Silica Particles>

[0215] The theoretical specific surface area SA' of the silica particles is determined using the D 50 The value of is calculated by the following formula (1).

[0216]

[0217] In the above formula (1), ρ is the density of the silica particles, which is 1.80 g / cm 3 or 2.20g / cm 3 value.

[0218] The irregularity N is calculated based on the SA and SA' obtained above and according to the formula of irregularity N = SA / SA'.

[0219] <Evaluation of Polishing Removal Rate and Scratches>

[0220] As a polishing object, an episulfide resin substrate described below was prepared, and (a) rough polishing, (b) intermediate polishing, and (c) fine polishing were performed in this order. For (a) rough polishing and (b) intermediate polishing, polishing was performed using the polishing composition described in each step below, under the polishing conditions described in each step below. It should be noted that in Tables 1 and 2 below, the case where "no intermediate polishing" is recorded indicates that (c) fine polishing was performed after (a) rough polishing, and (b) intermediate polishing was omitted. It should be noted that the GBIR and scratches of the polishing object were evaluated according to the criteria described below.

[0221] [(a) Coarse grinding]

[0222] (a1) Grinding object:

[0223] Episulfide resin substrate: 75mm diameter circular substrate, 0.550mm thickness

[0224] Flatness (thickness unevenness) GBIR: less than 0.5 μm

[0225] Surface condition: Multiple polishing marks (depth 100 to 1,500 nm)

[0226] (a2) Polishing composition:

[0227] Abrasive particles (aluminum oxide particles, particle size D 50 A polishing composition (pH 3.2) containing 12.5% ​​by mass of α-D-butyl carboxylic acid (α-D-butyl carboxylic acid: 0.7 μm), 10% by mass of aluminum nitrate, and 0.5% by mass of PVP (water: the remainder when the composition is made 100% by mass) was prepared.

[0228] (a3) Grinding conditions:

[0229] Polishing equipment: Double-side polishing machine 6BN (Hamai Industry Co., Ltd.)

[0230] Plate diameter: 380mm

[0231] Polishing pad: Polyurethane pad (Shore D43.0, Shore A95) (Fujibo Ehime Co., Ltd. product name TYN13MP)

[0232] Lower plate speed: 45rpm

[0233] Upper plate speed: 0rpm

[0234] Internal gear: 60%

[0235] Sun gear (forward): 150%

[0236] Grinding pressure: 3.3psi

[0237] Polishing composition flow rate (slurry flow rate): 10 mL / min

[0238] Grinding time: 10 minutes.

[0239] [(b) Intermediate grinding]

[0240] (b1) Grinding object:

[0241] The rough-polished object (episulfide resin substrate) obtained by the rough polishing in step (a) above: a circular substrate with a diameter of 75 mm and a thickness of 0.502 mm.

[0242] Flatness (thickness unevenness) GBIR: less than 0.5 μm

[0243] ·Surface condition…Scratches: C.

[0244] (b2) Polishing composition:

[0245] Use abrasive particles (colloidal silica, particle size D 50 A polishing composition (pH 3.2) containing 15% by mass of α-D-[3-nitrogen]-piperidinium (α-D-piperidinium phosphate, 187 nm), 8% by mass of aluminum nitrate, and 0.1% by mass of PVP (water: the remainder when the composition is made 100% by mass) was prepared.

[0246] (b3) Grinding conditions:

[0247] Polishing equipment: Double-side polishing machine 6BN (Hamai Industry Co., Ltd.)

[0248] Plate diameter: 380mm

[0249] Polishing pad: Polyurethane pad (Shore D43.0, Shore A95) (Fujibo Ehime Co., Ltd. product name TYN13MP)

[0250] Lower plate speed: 45rpm

[0251] Upper plate speed: 0rpm

[0252] Internal gear: 60%

[0253] Center gear (forward): 150%

[0254] Grinding pressure: 2.9psi

[0255] Polishing composition flow rate (slurry flow rate): 10 mL / min

[0256] Grinding time: 5 minutes.

[0257] [(c) Fine grinding]

[0258] (c1-1) Grinding object:

[0259] The object to be polished after the intermediate polishing (episulfide resin substrate) obtained by the intermediate polishing in step (b) above: a circular substrate with a diameter of 75 mm and a thickness of 0.501 mm.

[0260] Flatness (thickness unevenness) GBIR: less than 0.5 μm

[0261] ·Surface condition…Scratches: B.

[0262] (c1-2) Polishing composition:

[0263] The polishing compositions of Examples 1 to 17 and Comparative Examples 1 and 2 obtained above were used. The details of each polishing composition are shown in Tables 1 and 2.

[0264] (c1-3) Grinding conditions:

[0265] Polishing equipment: Double-side polishing machine 6BN (Hamai Industry Co., Ltd.)

[0266] Plate diameter: 380mm

[0267] Abrasive pad:

[0268] (a) Suede leather pad (Shore A73.0) (Fujibo Ehime Co., Ltd., product name K-1W-202U-SD)

[0269] (b) Polyurethane pad (Shore D43.0, Shore A95) (product name: TYN13MP, manufactured by Fujibo Ehime Co., Ltd.) (in Tables 1 and 2, polyurethane is referred to as PU)

[0270] (c) Non-woven fabric pad (Shore A67.0) (SUBA800 manufactured by Nitta DuPont Incorporated)

[0271] Lower plate speed: 45rpm

[0272] Upper plate speed: 0rpm

[0273] Internal gear: 60%

[0274] Center gear (forward): 150%

[0275] Grinding pressure: 2.9psi

[0276] Polishing composition flow rate (slurry flow rate): 5 mL / min, 10 mL / min, or 25 mL / min

[0277] Grinding time: 5 minutes.

[0278] (c2-1) Grinding object:

[0279] The rough-polished object (episulfide resin substrate) obtained by the rough polishing in step (a) above: a circular substrate with a diameter of 75 mm and a thickness of 0.502 mm.

[0280] Flatness (thickness unevenness) GBIR: less than 0.5 μm

[0281] ·Surface condition…Scratches: C.

[0282] (c2-2) Polishing composition:

[0283] The polishing composition of Example 9 obtained above was used. The details of the polishing composition are shown in Table 2.

[0284] (c2-3) Grinding conditions:

[0285] Polishing equipment: Double-side polishing machine 6BN (Hamai Industry Co., Ltd.)

[0286] Plate diameter: 380 [mm]

[0287] Polishing pad: Suede leather pad (Shore A73.0) (Fujibo Ehime Co., Ltd. product name K-1B-041U)

[0288] Lower plate speed: 45rpm

[0289] Upper plate speed: 0rpm

[0290] Internal gear: 60%

[0291] Center gear (forward): 150%

[0292] Grinding pressure: 2.9psi

[0293] Polishing composition flow rate (slurry flow rate): 10 mL / min

[0294] Grinding time: 10 minutes.

[0295] Evaluation Methods

[0296] After the fine polishing (c) described above, the polishing removal rate of the polished object (episulfide-based resin substrate) was evaluated according to the polishing removal rate evaluation method described below. Furthermore, the scratches on the polished surface of the polished object (episulfide-based resin substrate surface) were evaluated according to the scratch evaluation method described below.

[0297] (Grinding removal rate evaluation method)

[0298] 1. Using an analytical balance XS205 (manufactured by METTLER TOLEDO), the mass of the object to be polished before and after polishing was measured, and the mass change ΔM (kg) of the object to be polished before and after polishing was calculated from the difference between the two values.

[0299] 2. Divide the mass change ΔM [kg] of the object before and after polishing by the specific gravity of the object (calculated by assuming the specific gravity of the material to be polished: the specific gravity of the resin is 1.41) to calculate the volume change ΔV [m 3 〕;

[0300] 3. The volume change of the polishing object before and after polishing ΔV〔m 3 〕divided by the area of ​​the polishing surface of the polishing object s〔m 2 ], and thus calculate the thickness change Δd〔m〕 of the polishing object before and after polishing;

[0301] 4. Divide the thickness change Δd (m) before and after polishing by the polishing time t (min), and convert the unit to [nm / min]. This value is the polishing removal rate v (nm / min).

[0302] (Evaluation method for scratches)

[0303] Fine polishing was performed under the above conditions, and the surface condition of the polished object (episulfide-based resin substrate) after fine polishing was measured and evaluated for scratches according to the following evaluation criteria. A rating of A or B indicates practical use. Here, scratches are damage with a depth of less than 100 nm as measured using an AFM (atomic force microscope) (AFM Park NX-HDM manufactured by Park Systems Corporation).

[0304] Evaluation benchmarks;

[0305] A: Under halogen light source, there are no scratches or only one scratch can be confirmed;

[0306] B: Under halogen light source, more than 2 and less than 9 scratches can be confirmed;

[0307] C: Ten or more scratches can be observed under a halogen light source.

[0308] (Evaluation method of thickness unevenness (GBIR))

[0309] Using a NIDEK Flatness Tester FT-900, GBIR (excluding the edge area of ​​5 mm) was measured in accordance with SEMI standards. The measured values ​​were evaluated according to the following seven levels. A smaller GBIR value indicates a flatter surface and less uneven thickness.

[0310] Evaluation benchmarks;

[0311] <0.5: less than 0.5μm

[0312] 0.5~1: 0.5μm or more and 1.0μm or less

[0313] 1<<1.5: more than 1.0μm and less than 1.5μm

[0314] 1.5~2: 1.5μm or more and 2.0μm or less

[0315] 2<<2.5: more than 2.0μm and less than 2.5μm

[0316] 2.5~3: 2.5μm or more and 3.0μm or less

[0317] >3: exceeds 3.0μm.

[0318] (Evaluation method of root mean square height (Rms))

[0319] Non-contact 3D surface shape measurement using a white interferometer was performed using a Zygo NewView9000 (manufactured by AMETEK) in accordance with JIS B 0601: 2013. The root mean square height (Rms) was measured. A smaller value for the root mean square height (Rms) indicates a smoother surface.

[0320] As described above, the results of the fine polishing process using the polishing compositions of Examples 1 to 17 and Comparative Examples 1 and 2 showed that the thickness of the polished object after fine polishing with each polishing composition was within the range of 0.497 mm to 0.500 mm. The evaluation results of the polishing removal rate, GBIR, and scratches are shown in Tables 1 and 2 below.

[0321] [Table 1]

[0322]

[0323] [Table 2]

[0324]

[0325] As is clear from Tables 1 and 2 above, the polishing compositions of the Examples are superior in terms of improving the polishing removal rate of the polishing object (episulfide-based resin substrate) and reducing the uneven thickness of the polished object (episulfide-based resin substrate) after polishing. On the other hand, the polishing compositions of the Comparative Examples are inferior to those of the Examples in terms of either the polishing removal rate of the polishing object (episulfide-based resin substrate) or the uneven thickness of the polished object (episulfide-based resin substrate) after polishing. 50 : 0.7 μm) as the abrasive grains of the comparative example (containing 8 mass % of aluminum sulfate and 0.1 mass % of PVP as polishing accelerators, pH 6.8; not described in Tables 1 and 2 above), although polishing was carried out under the same polishing conditions as in Example 7, defects with a damage depth of 100 nm or more remained in the AFM, and the surface quality of the finished product in the polishing process was not obtained.

[0326] This application is based on Japanese Patent Application No. 2024-054024 filed on March 28, 2024 and Japanese Patent Application No. 2025-049365 filed on March 25, 2025, the disclosures of which are incorporated herein by reference in their entirety.

Claims

1. A polishing composition for polishing an object to be polished comprising a resin material. The polishing composition contains silica particles and water. The average particle size D of the silicon dioxide particles 50 It is 50nm or more.

2. The polishing composition according to claim 1, further comprising a polishing accelerator, The polishing accelerator is one or more selected from the group consisting of aluminum salts of monobasic acids, pyrrolidone compounds, and caprolactam compounds.

3. The polishing composition according to claim 1 or 2, wherein For the silica particles, the particle size at which the cumulative frequency from the smaller particle size side is 50% in the volume-based particle size distribution is defined as D. 50 , the BET specific surface area is set as SA, and the D 50 When the calculated theoretical specific surface area is SA', the irregularity N represented by irregularity N=SA / SA' is 1.2 or more.

4. The polishing composition according to claim 1 or 2, wherein The average particle size D of the silicon dioxide particles 50 It is 50 nm or more and less than 200 nm.

5. The polishing composition according to claim 2, wherein The polishing accelerator comprises the aluminum salt of the monobasic acid and the pyrrolidone compound.

6. The polishing composition according to claim 1 or 2, wherein Regarding the silica particles, the particle size at which the cumulative frequency from the smaller particle size side is 10% in the volume-based particle size distribution of the silica particles is defined as D. 10 The particle size at which the cumulative frequency of the silica particles is 90% from the smaller particle size side in the volume-based particle size distribution is defined as D 90 When D 90 Relative to D 10 D 90 / D 10 2.0 or above.

7. The polishing composition according to claim 1 or 2, wherein The resin material is an optical resin material.

8. The polishing composition according to claim 1 or 2, wherein The average thickness of the object to be polished before polishing is 1 mm or less.

9. The polishing composition according to claim 1 or 2, wherein The flatness of the polished object after polishing as defined by GBIR is 1.5 μm or less.

10. A polishing composition for polishing an object to be polished made of a resin material, the polishing composition comprising silica particles, a polishing accelerator, and water. The polishing accelerator is one or more selected from the group consisting of aluminum salts of monobasic acids, pyrrolidone compounds, and caprolactam compounds. Regarding the silica particles, the particle size at which the cumulative frequency from the smaller particle size side is 50% in the volume-based particle size distribution of the silica particles is defined as D. 50 , the BET specific surface area is set as SA, and the D 50 When the calculated theoretical specific surface area is SA', the irregularity N represented by irregularity N=SA / SA' is 1.5 or more. 11 . A polishing method comprising the step of polishing an object to be polished comprising a resin material using the polishing composition according to claim 1 . 12 . A method for producing an optical member, comprising the step of polishing an optical resin material by the polishing method according to claim 11 .

13. A polishing method comprising the step of supplying a polishing composition between an object to be polished comprising a resin material and a polishing pad to polish the object to be polished. The polishing composition contains silica particles and water. The average particle size D of the silicon dioxide particles 50 It is 50nm or more.

14. The grinding method according to claim 13, wherein: The polishing pad has a Shore A hardness of 40 or greater.

15. The grinding method according to claim 13 or 14, wherein The polishing composition further comprises a polishing accelerator, The polishing accelerator is one or more selected from the group consisting of aluminum salts of monobasic acids, pyrrolidone compounds, and caprolactam compounds.

16. The grinding method according to claim 13 or 14, wherein For the silica particles, the particle size at which the cumulative frequency from the smaller particle size side is 50% in the volume-based particle size distribution is defined as D. 50 , the BET specific surface area is set as SA, and the D 50 When the calculated theoretical specific surface area is SA', the irregularity N represented by irregularity N=SA / SA' is 1.2 or more.

17. The grinding method according to claim 13 or 14, wherein: The average particle size D of the silicon dioxide particles 50 It is 50 nm or more and less than 200 nm.

18. The grinding method according to claim 13 or 14, wherein The flatness of the polished object after polishing as defined by GBIR is 1.5 μm or less.

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