Polishing composition, method for producing the polishing composition, and polishing method

Abstract

To provide an abrasive composition with excellent processing power. [Solution] An abrasive composition comprising abrasive grains, an emulsifier, a polishing accelerator, a hydrophobic dispersion medium, and water, wherein the emulsifier is a polyoxyalkylene alkyl ether, and the polishing accelerator is a surfactant (however, a surfactant different from the emulsifier).

Description

[Technical Field]

[0001] The present invention relates to an abrasive composition, a method for producing an abrasive composition, and a polishing method. [Background technology]

[0002] Painted surfaces of automobile bodies and other vehicles are polished to remove scratches that occur during use, and to create a uniform paint surface when repainting to repair scratches. In this case, it is required that the polished painted surface be free of scratches, that the underlying color is clearly visible, and that it does not appear whitish due to fine scratches on the surface caused during polishing. A known method for polishing painted surfaces is to use a buff (polishing wheel) and a polisher (polishing machine) attached to rotate the buff, and to polish the surface by rotating the buff with the polisher while interposing a polishing composition between the painted surface and the buff. An example of such a polishing composition is the polishing composition described in Patent Document 1.

[0003] Common types of buffing pads used for polishing painted surfaces such as car bodies include wool buffs (sheep's wool buffs) and sponge buffs (foamed urethane buffs). Generally, the process of removing scratches from painted surfaces is divided into rough polishing and finish polishing. The purpose of rough polishing is to remove scratches from the painted surface, while the purpose of finish polishing is to remove any minute scratches or whitening that may have occurred during rough polishing. Wool buffs are used for rough polishing, and sponge buffs are used for finish polishing. While it is sometimes possible to remove scratches with finish polishing alone, combining rough polishing and finish polishing allows the polishing process to be completed in a shorter time.

[0004] Polishing a painted surface involves dropping an appropriate amount of polishing compound (polishing composition) onto the painted surface or onto the buffing pad, and then spreading the polishing compound on the painted surface with the buffing pad. Ideally, the buffing pad should be rotated using a polisher while being applied to the painted surface, so that the polishing of the painted surface is complete after the buffing pad has passed, and no polishing compound remains on the painted surface. [Prior art documents] [Patent Documents]

[0005] [Patent Document 1] Japanese Patent Publication No. 2012-251099 [Overview of the Initiative] [Problems that the invention aims to solve]

[0006] The polishing composition described in Patent Document 1 above is characterized by the fact that the polished surface remains wet after polishing, but there is room for improvement in terms of processing power.

[0007] Therefore, the problem that the present invention aims to solve is to provide an abrasive composition having excellent processing power. [Means for solving the problem]

[0008] In order to solve the above problems, the inventors diligently conducted research. As a result, they found that the above problems could be solved by an abrasive composition comprising abrasive grains, an emulsifier, a polishing accelerator, a hydrophobic dispersion medium, and water, wherein the emulsifier is a polyoxyalkylene alkyl ether and the polishing accelerator is a surfactant (however, a surfactant different from the emulsifier), and thus completed the present invention. [Effects of the Invention]

[0009] According to the present invention, an abrasive composition having excellent processing power is provided. [Modes for carrying out the invention]

[0010] The embodiments for carrying out the present invention will be described in detail below. The embodiments shown herein are illustrative examples for embodying the technical idea of ​​the present invention and do not limit the present invention. Therefore, all other implementable forms, methods of use, and operating techniques that can be conceived by those skilled in the art without departing from the spirit of the present invention are included in the scope and spirit of the present invention, as well as in the claims and their equivalents. The embodiments described herein can be arbitrarily combined to form other embodiments. In this specification, "X~Y" indicating a range means "X or more and Y or less," and "weight" and "mass," "weight%" and "mass%," and "parts by weight" and "parts by mass" are treated as synonyms. In this specification, unless otherwise specified, operations and measurements of physical properties, etc., are performed under conditions of room temperature (20°C or more and 25°C or less) / relative humidity 40%RH or more and 50%RH or less.

[0011] <Polishing composition> The present invention relates to an abrasive composition comprising abrasive grains, an emulsifier, a polishing accelerator, a hydrophobic dispersion medium, and water, wherein the emulsifier is a polyoxyalkylene alkyl ether, and the polishing accelerator is a surfactant (however, a surfactant different from the emulsifier). The abrasive composition of the present invention having such a configuration exhibits excellent processing power when polishing an object to be polished as a rough polish or finish polish. "Excellent processing power" means, for example, in the evaluation of processing power in the removal (elimination) of scratches after polishing, that the time taken to remove scratches is short.

[0012] The present invention has found that the polishing composition significantly improves processing power by containing a specific polyoxyalkylene alkyl ether (for example, a polyoxyethylene alkyl ether having an alkyl group with 8 to 12 carbon atoms) as an emulsifier and a surfactant different from the emulsifier as a polishing accelerator. Although the details of this mechanism are unknown, it is thought that by using the emulsifier and polishing accelerator in combination, the affinity of the polishing composition to the buff during polishing (the ability of the polishing composition to spread on the buff surface) is significantly improved. As a result, the object to be polished (the surface to be polished) is polished by a buff whose surface is sufficiently saturated with the polishing composition, and it is thought that mechanical force (for example, abrasive particles) can be effectively applied to the object to be polished (the surface to be polished), allowing for efficient polishing.

[0013] It should be noted that the above mechanism is based on speculation, and the present invention is not limited in any way to the above mechanism.

[0014] The following describes each component included in the polishing composition of this embodiment.

[0015] [Abrasive grains] The polishing composition of this embodiment contains abrasive grains. The abrasive grains have the effect of mechanically polishing the object to be polished.

[0016] Specific examples of abrasive grains used in this embodiment include, for example, metal oxides such as aluminum oxide (alumina), cerium oxide (ceria), zirconium oxide, titanium oxide (titania), tin oxide, and manganese oxide; metalloid oxides such as silicon oxide (silica); metal carbides such as titanium carbide; metalloid carbides such as silicon carbide; metal nitrides such as titanium nitride; metalloid nitrides such as silicon nitride; metal borides such as titanium boride and tungsten boride; silicate compounds such as zircon (ZrSiO4); and diamond. These abrasive grains may be used individually or in mixtures of two or more. Furthermore, commercially available abrasive grains may be used, or synthetic products may be used.

[0017] Among these abrasive grains, at least one selected from the group consisting of metal oxides and metal carbides is preferred, from the viewpoint that a variety of particle sizes are readily available and excellent machining power can be obtained, with metal oxides being more preferred, at least one of aluminum oxide (alumina), cerium oxide, and zirconium oxide being even more preferred, and aluminum oxide being particularly preferred. A mixture of alumina and zircon is also preferably used.

[0018] Furthermore, among aluminum oxides, those containing the α phase, or transitional crystalline phases such as the θ phase, δ phase, or γ phase, which are processes leading to the α phase, are suitable as abrasive grains due to their preferred crystalline structure. Preferably, they contain the α phase or the θ phase, and more preferably, they contain the α phase. In addition, it is thought that there is an optimal range depending on the degree of α-phase formation. Generally, the α phase crystalline structure is considered to be the hardest, but it is presumed that if the aluminum oxide is sintered sufficiently at high temperatures to form the α phase, the particle shape changes to round, and the processing power decreases. The α-phase formation rate can be used as a reference value to represent the degree of α phase contained in aluminum oxide. The lower limit of the preferred α-phase formation rate is 50% or more. More preferably, the lower limit of the α-phase formation rate is 60% or more, even more preferably 65% ​​or more, and particularly preferably 70% or more. Also, the upper limit of the preferred α-phase formation rate is 100% or less. More preferably, the upper limit of the α-phase formation rate is 99% or less, even more preferably 98% or less, and particularly preferably 97% or less. Specifically, the alpha-gelatinization rate of aluminum oxide is preferably 50% to 100%, more preferably 60% to 99%, even more preferably 65% ​​to 98%, and particularly preferably 70% to 97%. By setting the alpha-gelatinization rate within the above preferred range, an improvement in processing power, i.e., a reduction in scratch removal time, can be expected. The alpha-gelatinization rate of aluminum oxide particles can be calculated from the integral intensity ratio of (113) plane diffraction lines obtained by X-ray diffraction measurement using an X-ray diffraction analyzer (Ultima-IV, manufactured by Rigaku Corporation).

[0019] The lower limit of the average primary particle size of the abrasive grains is preferably 0.01 μm or more, more preferably 0.02 μm or more, still more preferably 0.05 μm or more, particularly preferably 0.08 μm or more, and most preferably 0.10 μm or more. The upper limit of the average primary particle size of the abrasive grains is preferably 1 μm or less, more preferably 0.85 μm or less, still more preferably 0.80 μm or less, particularly preferably 0.50 μm or less, and most preferably 0.30 μm or less. That is, the average primary particle size of the abrasive grains is preferably 0.01 μm or more and 1 μm or less, more preferably 0.02 μm or more and 0.85 μm or less, still more preferably 0.05 μm or more and 0.80 μm or less, particularly preferably 0.08 μm or more and 0.50 μm or less, and most preferably 0.10 μm or more and 0.30 μm or less. In one embodiment, the abrasive grains have an average primary particle size of 0.05 μm or more and 1 μm or less. When the average primary particle size of the abrasive grains is within the above range, the machining force can be improved, and the object to be polished can be polished well in both rough polishing and finish polishing. The average primary particle size of the abrasive grains can be calculated, for example, based on the specific surface area (SA) of the abrasive grains calculated by the BET method and the density of the abrasive grains. More specifically, the average primary particle size of the abrasive grains adopts the value measured by the method described in the examples.

[0020] In one embodiment, the lower limit of the average secondary particle diameter of the abrasive grains is preferably 0.1 μm or more, more preferably 0.2 μm or more, still more preferably 0.5 μm or more, particularly preferably 1.0 μm or more, and most preferably 1.5 μm or more. Also, the upper limit of the average secondary particle diameter of the abrasive grains is preferably 30 μm or less, more preferably 20 μm or less, still more preferably 10 μm or less, particularly preferably 5 μm or less, and most preferably 4.5 μm or less. From the above, the average secondary particle diameter of the abrasive grains is preferably 0.1 μm or more and 30 μm or less, more preferably 0.2 μm or more and 20 μm or less, still more preferably 0.5 μm or more and 10 μm or less, particularly preferably 1.0 μm or more and 5 μm or less, and most preferably 1.5 μm or more and 4.5 μm or less. In one embodiment, the abrasive grains have an average secondary particle diameter of 1 μm or more and 20 μm or less. When the average secondary particle diameter of the abrasive grains is within the above range, the machining force can be improved, and the object to be polished can be polished well in both rough polishing and finish polishing. The average secondary particle diameter of the abrasive grains is the average secondary particle diameter measured after subjecting them to dispersion treatment by ultrasonic waves.

[0021] The ratio of the average secondary particle diameter to the average primary particle diameter of the abrasive grains (average secondary particle diameter / average primary particle diameter) is preferably 2 or more and 100 or less. Hereinafter, the ratio of the average secondary particle diameter to the average primary particle diameter of the abrasive grains (average secondary particle diameter / average primary particle diameter) is referred to as the aggregation ratio. In the present embodiment, the lower limit of the aggregation ratio is preferably 5 or more, more preferably 8 or more, and still more preferably 10 or more. The upper limit of the aggregation ratio is preferably 80 or less, more preferably 50 or less, and still more preferably 30 or less. When the aggregation ratio is within the above range, the machining force can be improved, and the object to be polished can be polished well in both rough polishing and finish polishing.

[0022] In this specification, the average secondary particle diameter of the abrasive grains is defined as the integrated 50% particle diameter (D50) based on the volume-based particle size distribution, and can be measured, for example, by the laser diffraction scattering method.

[0023] The lower limit of the abrasive grain content in the polishing composition is preferably 0.1% by mass or more, more preferably 0.5% by mass or more, even more preferably 1% by mass or more, particularly preferably 3% by mass or more, and most preferably 5% by mass or more, based on the total mass of the polishing composition. By having an abrasive grain content of 0.1% by mass or more, the processing force can be appropriately controlled, and the workpiece can be polished well in both rough polishing and finish polishing.

[0024] Furthermore, the upper limit of the abrasive grain content in the polishing composition is preferably 60% by mass or less, more preferably 50% by mass or less, even more preferably 45% by mass or less, particularly preferably 40% by mass or less, and most preferably 35% by mass or less, based on the total mass of the polishing composition. By having an abrasive grain content of 60% by mass or less, the manufacturing cost of the polishing composition is reduced, and the processing force is appropriately controlled, allowing for good polishing of the workpiece in both rough polishing and finish polishing.

[0025] According to one embodiment, the abrasive grains are contained in an amount of 5% to 50% by mass or 5% to 45% by mass relative to the total mass of the polishing composition.

[0026] [emulsifier] The polishing composition according to this embodiment contains a polyoxyalkylene alkyl ether as an emulsifier. The inclusion of an emulsifier (polyoxyalkylene alkyl ether) in the polishing composition according to this embodiment improves its affinity to a buff (e.g., a wool buff), and polishing is performed with a buff that contains a sufficient amount of the polishing composition, allowing for the effective application of mechanical force (e.g., abrasive particles) and efficient polishing.

[0027] According to one embodiment, the polyoxyalkylene alkyl ether is given by the following formula (1): H-(OA) n -OR (1) [Here, A represents a linear or branched alkylene group having 2 to 4 carbon atoms, R is an alkyl group having 4 to 18 carbon atoms, and n is the average number of added moles of alkylene oxide (-(OA)-)] It is represented as follows.

[0028] In formula (1), A represents a linear or branched alkylene group having 2 to 4 carbon atoms. Examples of linear or branched alkylene groups having 2 to 4 carbon atoms include ethylene (-CH2CH2-), methylmethylene (-CH2(CH3)-), trimethylene (-CH2CH2CH2-), 2-methylethylene (-CH2-CH(CH3)-), tetramethylene (-CH2CH2CH2CH2-), 1-methyltrimethylene (-CH(CH3)CH2CH2-), 2-methyltrimethylene (-CH2CH(CH3)CH2-), 1,1-dimethylmethylene (-C(CH3)(CH3)CH2-), and 1,2-dimethylmethylene (-CH(CH3)CH(CH3)-). These alkylene groups form oxyalkylene groups with oxygen atoms. These oxyalkylene groups (AO groups) may be identical or a mixture of different groups (block or random), preferably an oxyethylene group (A is an ethylene group) alone, an oxypropylene group (A is a 2-methylethylene group) alone, or a mixture of oxyethylene and oxypropylene groups (block or random), more preferably an oxyethylene group or an oxypropylene group, and particularly preferably an oxyethylene group (A is an ethylene group).

[0029] In formula (1), R represents an alkyl group having 4 to 18 carbon atoms. Preferably, R in formula (1) is an alkyl group having 6 to 16 carbon atoms, and more preferably 8 to 12 carbon atoms. For example, R in formula (1) (i.e., the alkyl group of the polyoxyalkylene alkyl ether) may be an alkyl group having 8 to less than 12 carbon atoms, and from the viewpoint of foaming properties, it may also be an alkyl group having 9 to less than 12 carbon atoms, an alkyl group having 9 to 11 carbon atoms, an alkyl group having 9 to less than 11 carbon atoms, or an alkyl group having 9 to 10 carbon atoms.

[0030] The alkyl group having 4 to 18 carbon atoms may be linear, branched, or cyclic, but it is preferably linear or branched, and more preferably linear. Specific examples of alkyl groups having 4 to 18 carbon atoms are not particularly limited, but include n-butyl group, sec-butyl group, tert-butyl group, isobutyl group (2-methylpropyl group), 2-ethylbutyl group, 3,3-dimethylbutyl group, n-pentyl group, isopentyl group (3-methylbutyl group), neopentyl group (2,2-dimethylpropyl group), tert-pentyl group (2-methyl-2-butyl group), cyclopentyl group, 1-methylpentyl group, 3-methylpentyl group, 2-ethylpentyl group, 4-methyl-2-pentyl group, n-hexyl group, 1-methylhexyl group, 2-ethylhexyl group, 2-butylhexyl group, cyclohexyl group, 4-methylcyclohexyl group, 4-tert-butylcyclohexyl group, n-heptyl group, 1-methylpeptyl group, 2,2-dimethyl Heptyl group, 2-ethylheptyl group, 2-butylheptyl group, n-octyl group, tert-octyl group (2-methyl-2-pentyl group), 2-ethyloctyl group, 2-butyloctyl group, 2-hexyloctyl group, 3,7-dimethyloctyl group, cyclooctyl group, n-nonyl group, n-decyl group, isodecyl group (8-methylnonyl group), adamantyl group, 2-ethyldecyl group, 2 Examples include butyldecyl group, 2-hexyldecyl group, 2-octyldecyl group, n-undecyl group, n-dodecyl group, 2-ethyldodecyl group, 2-butyldodecyl group, 2-hexyldodecyl group, 2-octyldecyl group, n-tridecyl group, n-tetradecyl group, n-pentadecyl group, n-hexadecyl group, 2-ethylhexadecyl group, n-heptadecyl group, and n-octadecyl group. Among these, linear alkyl groups are preferred, n-decyl group, n-undecyl group, n-dodecyl group, n-tridecyl group, n-tetradecyl group, n-pentadecyl group, and n-hexadecyl group are more preferred, and n-decyl group is even more preferred.

[0031] In formula (1), n ​​represents the average number of moles of oxyalkylene groups represented by AO, and is a number between 1 and 20. Preferably, n is a number between 2 and 15, more preferably between 3 and 12, even more preferably between 3 and 10, particularly preferably between 4 and 9, and most preferably between 4 and 8. According to one embodiment, n is a number between 2 and 12, 2 and 10, 3 and 15, 3 and 10, 4 and 15, 4 and 12, 4 and 15, or 4 and 12. By having the average number of moles of oxyalkylene groups added within the above range, the affinity to the buff is improved during polishing, and the processing power is further improved.

[0032] According to one embodiment, the emulsifier is a polyoxyethylene alkyl ether. The use of a polyoxyethylene alkyl ether as the emulsifier improves its affinity to the buff during polishing, further enhancing the processing power.

[0033] The preferred form of formula (1) above also applies when the emulsifier is a polyoxyethylene alkyl ether. Specifically, the alkyl group of the polyoxyethylene alkyl ether may be, for example, an alkyl group having 4 to 18 carbon atoms, 6 to 16 carbon atoms, 8 to 12 carbon atoms, or 8 to less than 12 carbon atoms. Furthermore, from the viewpoint of foaming properties, it may also be an alkyl group having 9 to less than 12 carbon atoms, an alkyl group having 9 to 11 carbon atoms, an alkyl group having 9 to less than 11 carbon atoms, or an alkyl group having 9 to 10 carbon atoms. The alkyl group of the polyoxyethylene alkyl ether may be linear, branched, or cyclic, but it is preferably a linear or branched alkyl group.

[0034] When the emulsifier is a polyoxyethylene alkyl ether, the average number of moles of oxyethylene groups added by the polyoxyethylene alkyl ether is preferably 15 moles or less, more preferably 12 moles or less, even more preferably less than 10 moles, particularly preferably 9 moles or less, and most preferably 8 moles or less. Furthermore, the average number of moles of oxyethylene groups added by the polyoxyethylene alkyl ether is preferably 2 moles or more, more preferably more than 2 moles, even more preferably 3 moles or more, particularly preferably 4 moles or more, and most preferably more than 4 moles. By having the average number of moles of oxyethylene groups added by the polyoxyethylene alkyl ether within the above range, the affinity to the buff during polishing is improved, and the processing power is further enhanced.

[0035] Examples of polyoxyalkylene alkyl ethers include polyoxyethylene 2-ethylhexyl ether, polyoxypropylene 2-ethylhexyl ether, polyoxyethylene-polyoxypropylene 2-ethylhexyl ether, polyoxyethylene octyl ether, polyoxypropylene octyl ether, polyoxyethylene-polyoxypropylene octyl ether, polyoxyethylene nonyl ether, polyoxypropylene nonyl ether, polyoxyethylene decyl ether, polyoxypropylene decyl ether, polyoxyethylene-polyoxypropylene decyl ether, and polyoxyethylene isodecyl ether. Examples include polyoxypropylene isodecyl ether, polyoxyethylene undecyl ether, polyoxypropylene undecyl ether, polyoxyethylene dodecyl ether (polyoxyethylene lauryl ether), polyoxypropylene dodecyl ether (polyoxypropylene lauryl ether), polyoxyethylene tetradecyl ether, polyoxypropylene tetradecyl ether, polyoxyethylene-polyoxypropylene tetradecyl ether, polyoxyethylene hexadecyl ether, polyoxypropylene hexadecyl ether, and polyoxyethylene-polyoxypropylene hexadecyl ether. These polyoxyalkylene ethers as emulsifiers may be used alone or in mixtures of two or more. Furthermore, when using two or more polyoxyalkylene ethers, one may be used as an emulsifier and one or more of the others may be used as polishing accelerators as described later. If the polishing accelerator is a compound other than a polyoxyalkylene alkyl ether, then two or more polyoxyalkylene alkyl ethers may all be used as emulsifiers.

[0036] In the polishing composition of the present invention, the HLB of the polyoxyalkylene alkyl ether is preferably 10 or more and 14 or less, more preferably 11 or more and less than 14, and even more preferably 12 or more and less than 14. Here, the HLB (Hydrophilic-Lipophilic Balance) value represents the degree of affinity of the surfactant to water and oil (organic compounds insoluble in water).

[0037] The weight-average molecular weight of the polyoxyalkylene alkyl ether is preferably 150 or more, more preferably 200 or more, even more preferably 250 or more, particularly preferably 300 or more, and most preferably 350 or more. The weight-average molecular weight of the polyoxyalkylene alkyl ether is preferably 1000 or less, more preferably 800 or less, even more preferably 600 or less, particularly preferably 550 or less, and most preferably 500 or less. When the weight-average molecular weight of the polyoxyalkylene alkyl ether is within the above range, the polyoxyalkylene alkyl ether can disperse the abrasive grains well, resulting in improved processing power and better polishing of the workpiece. The weight-average molecular weight of the polyoxyalkylene alkyl ether can be the value measured by the GPC method (water-based, polyethylene oxide equivalent).

[0038] The emulsifier (polyoxyalkylene alkyl ether) content is 2.0 mol% or more, when the molar content of the hydrophobic dispersion medium described later is set to 100 mol%,. Preferably, the emulsifier (polyoxyalkylene alkyl ether) content is 2.8 mol% or more, more preferably 3.0 mol% or more, and most preferably 3.2 mol% or more, when the molar content of the hydrophobic dispersion medium described later is set to 100 mol%,. Furthermore, preferably, the emulsifier (polyoxyalkylene alkyl ether) content is 20.0 mol% or less, more preferably 18.0 mol% or less, even more preferably 15.0 mol% or less, particularly preferably 14.0 mol% or less, and most preferably 12.0 mol% or less, when the molar content of the hydrophobic dispersion medium described later is set to 100 mol%,. In one embodiment, the content of the emulsifier (polyoxyalkylene alkyl ether) may be 10.0 mol% or less, 9.0 mol% or less, 8.0 mol% or less, 7.0 mol% or less, or 6.5 mol% or less, when the molar content of the hydrophobic dispersion medium described later is taken as 100 mol%. Preferably, the content of the emulsifier (polyoxyalkylene alkyl ether) is 2.0 mol% to 20.0 mol%, more preferably 2.8 mol% to 18.0 mol%, even more preferably 3.0 mol% to 15.0 mol%, particularly preferably 3.2 mol% to 14.0 mol%, and most preferably 3.2 mol% to 12.0 mol%, when the molar content of the hydrophobic dispersion medium described later is taken as 100 mol%. By having the content of the emulsifier (polyoxyalkylene alkyl ether) in the hydrophobic dispersion medium within the above range, the affinity to the buff is improved during polishing, and the processing power is further improved.

[0039] The content of the emulsifier (polyoxyalkylene alkyl ether) in the polishing composition is preferably 0.001 mol / kg or more, more preferably 0.002 mol / kg or more, even more preferably 0.003 mol / kg or more, particularly preferably 0.005 mol / kg or more, and most preferably 0.010 mol / kg or more, based on the total mass of the polishing composition. According to one embodiment, the content of the emulsifier (polyoxyalkylene alkyl ether) in the polishing composition is 0.025 mol / kg or more, based on the total mass of the polishing composition. Furthermore, the content of the emulsifier (polyoxyalkylene alkyl ether) in the polishing composition is preferably 0.250 mol / kg or less, more preferably 0.200 mol / kg or less, even more preferably 0.150 mol / kg or less, particularly preferably 0.120 mol / kg or less, and most preferably 0.100 mol / kg or less, based on the total mass of the polishing composition. By having the emulsifier (polyoxyalkylene alkyl ether) content within the above range, the affinity to the buff during polishing is improved, and the processing power is further enhanced.

[0040] According to one embodiment, the emulsifier is a polyoxyethylene alkyl ether having an alkyl group with 8 to 12 carbon atoms, and the emulsifier is present in an amount of 2.0 mol% or more when the molar content of the hydrophobic dispersion medium is 100 mol%.

[0041] The content of the emulsifier (polyoxyalkylene alkyl ether) in the polishing composition is preferably 0.8% by mass or more, more preferably 0.9% by mass or more, even more preferably 1.0% by mass or more, particularly preferably 1.1% by mass or more, and even more preferably 1.5% by mass or more, based on the total mass (100% by mass) of the polishing composition. Furthermore, the content of the emulsifier (polyoxyalkylene alkyl ether) in the polishing composition is preferably 10% by mass or less, more preferably 8% by mass or less, even more preferably 7% by mass or less, particularly preferably 6% by mass or less, and most preferably 5% by mass or less, based on the total mass of the polishing composition. When the content of the emulsifier (polyoxyalkylene alkyl ether) is within the above range, the affinity to the buff is improved during polishing, and the processing power is further improved.

[0042] [Polishing accelerator] The polishing composition according to this embodiment contains a surfactant as a polishing accelerator. The polishing accelerator is a surfactant other than the polyoxyalkylene alkyl ether used as an emulsifier.

[0043] The polishing composition according to this embodiment contains an emulsifier (polyoxyalkylene alkyl ether) and a polishing accelerator, which improves its affinity to a buff (e.g., a wool buff). Polishing is performed with a buff that contains a sufficient amount of the polishing composition, allowing for the effective application of mechanical force (e.g., abrasive particles) and efficient polishing.

[0044] In the polishing composition according to this embodiment, the polishing accelerator is, for example, a nonionic surfactant other than the polyoxyalkylene alkyl ether used in the emulsifier, and / or an ionic surfactant. The ionic surfactant is one or more selected from the group consisting of cationic surfactants, anionic surfactants, and amphoteric surfactants. That is, the polishing accelerator is, for example, one or more selected from the group consisting of nonionic surfactants other than the polyoxyalkylene alkyl ether used in the emulsifier, cationic surfactants, anionic surfactants, and amphoteric surfactants. Of these, the polishing accelerator is preferably one or more selected from the group consisting of nonionic surfactants other than the polyoxyalkylene alkyl ether used in the emulsifier, cationic surfactants, and anionic surfactants, more preferably one or more selected from the group consisting of cationic surfactants and anionic surfactants, and even more preferably a cationic surfactant. According to one embodiment, the polishing accelerator includes a cationic surfactant. These polishing accelerators may be used individually or in a mixture of two or more.

[0045] Examples of nonionic surfactants include the polyoxyalkylene alkyl ethers used as emulsifiers mentioned above (excluding polyoxyalkylene alkyl ethers used as emulsifiers); polyoxyalkylene alkylaryl ethers such as polyoxyethylene nonylphenyl ether; polyoxyalkylene sorbitan fatty acid esters (polyoxyethylene sorbitan fatty acid esters) such as polyoxyethylene sorbitan monolaurate, polyoxyethylene sorbitan monopalmitate, polyoxyethylene sorbitan monostearate, polyoxyethylene sorbitan tristearate, polyoxyethylene sorbitan monooleate, polyoxyethylene sorbitan trioleate; sucrose fatty acid esters; polyoxyalkylene sorbitol fatty acid esters (polyoxyethylene sorbitol fatty acid esters) such as polyoxyethylene sorbitan tetraoleate; and polyethylene Examples include polyoxyalkylene fatty acid esters (polyoxyethylene fatty acid esters) such as polyethylene glycol monolaurate, polyethylene glycol monostearate, polyethylene glycol distearate, and polyethylene glycol monooleate; polyoxyalkylene alkylamines (polyoxyethylene alkylamines); polyoxyalkylene hydrogenated castor oil (polyoxyethylene hydrogenated castor oil); sorbitan fatty acid esters such as sorbitan monolaurate, sorbitan monomyristylate, sorbitan monopalmitate, sorbitan monostearate, sorbitan tristearate, sorbitan monooleate, sorbitan trioleate, sorbitan sesquioleate, and sorbitan distearate; glycerin fatty acid esters such as glycerol monostearate, glycerol monooleate, diglycerol monooleate, and self-emulsifying glycerol monostearate; alkyl alkanolamides; and the like.

[0046] Of these, the nonionic surfactant is the polyoxyalkylene alkyl ether described above (excluding the polyoxyalkylene alkyl ether used as an emulsifier). As for the polyoxyalkylene alkyl ether, for example, a polyoxyalkylene alkyl ether having a branched alkyl group is more preferred, and as for the linear alkyl group, having 4 to 18 carbon atoms is more preferred, having 6 to 16 carbon atoms is even more preferred, having 8 to 14 carbon atoms is particularly preferred, and having 8 to 12 carbon atoms is most preferred.

[0047] An example of anionic surfactants is one or more selected from the group consisting of carboxylates, sulfonates, sulfates, and phosphates. Preferably, the anionic surfactant is one or more selected from the group consisting of sulfonates, sulfates, and phosphates. According to one embodiment, the polishing accelerator is one or more selected from the group consisting of carboxylates, sulfonates, sulfates, and phosphates.

[0048] Examples of carboxylate salts include aliphatic monocarboxylates, polyoxyethylene alkyl ether carboxylates, alkyl hydroxy ether carboxylates, N-acyl sarcosine salts, and N-acyl glutamate salts.

[0049] Examples of sulfonates include alkyl sulfonates, alkylbenzene sulfonates (linear alkylbenzene sulfonates or branched alkylbenzene sulfonates), alkylnaphthalene sulfonates, naphthalene sulfonate-formaldehyde condensates, N-methyl-N-acyl tauric acid (alkanoyl methyl tauride), dialkyl sulfosuccinate salts, alkyl sulfosuccinate dis, and polyoxyethylene alkyl ether sulfosuccinate dis.

[0050] Examples of sulfate ester salts include alkyl sulfate ester salts (alkyl sulfates), polyoxyethylene alkyl ether sulfate ester salts, oil sulfate ester salts (sulfated oils), and sulfated fatty acid esters.

[0051] Examples of phosphate ester salts include alkyl phosphate salts (alkyl phosphates), polyoxyethylene alkyl ether phosphate salts (polyoxyethylene alkyl phosphates), and polyoxyethylene alkylphenyl ether phosphate salts (polyoxyethylene alkylphenyl phosphates).

[0052] Examples of cationic surfactants include quaternary ammonium salts and amine salts. In one embodiment, the polishing accelerator is a quaternary ammonium salt or an amine salt.

[0053] The quaternary ammonium salt preferably has an alkyl group having 12 to 24 carbon atoms or an alkenyl group having 12 to 24 carbon atoms, and more preferably has an alkyl group having 16 to 20 carbon atoms or an alkenyl group having 16 to 20 carbon atoms. The quaternary ammonium salt may also have a mixed alkyl group such as a coconut alkyl group.

[0054] It is preferable that the quaternary ammonium salt has a cationic moiety that contains at least one alkyl group having 12 to 24 carbon atoms or an alkenyl group having 12 to 24 carbon atoms. The cationic moiety of the quaternary ammonium salt may have substituents other than alkyl groups having 12 to 24 carbon atoms or alkenyl groups having 12 to 24 carbon atoms. These substituents are not particularly limited and may include, for example, hydrogen atoms, alkynyl groups, aryl groups, acyl groups, alkoxycarbonyl groups, alkoxy groups, aryloxycarbonyl groups, acyloxy groups, etc. According to one embodiment, the cationic moiety of the quaternary ammonium salt has no substituents other than alkyl groups or alkenyl groups. That is, it is preferable that the quaternary ammonium salt is a compound having four groups selected from the group consisting of alkyl groups and alkenyl groups.

[0055] The cation portion of the quaternary ammonium salt preferably has one or two alkyl groups having 12 to 24 carbon atoms or alkenyl groups having 12 to 24 carbon atoms, and more preferably one. The cation portion of the quaternary ammonium salt preferably has an alkyl group having less than 12 carbon atoms as an organic group other than an alkyl group having 12 to 24 carbon atoms or alkenyl groups having 12 to 24 carbon atoms, more preferably an alkyl group having 1 to 10 carbon atoms, even more preferably an alkyl group having 1 to 5 carbon atoms, and particularly preferably an alkyl group having 1 to 3 carbon atoms.

[0056] According to one embodiment, the cationic portion of the quaternary ammonium salt has one alkyl group having 12 to 24 carbon atoms or an alkenyl group having 12 to 24 carbon atoms and three alkyl groups having 1 to 3 carbon atoms; or two alkyl groups having 12 to 24 carbon atoms or an alkenyl group having 12 to 24 carbon atoms and two alkyl groups having 1 to 3 carbon atoms. Examples of such quaternary ammonium salts include alkyltrimethylammonium salt having an alkyl group having 12 to 24 carbon atoms; dialkyldimethylammonium salt having an alkyl group having 12 to 24 carbon atoms; alkenyltrimethylammonium salt having an alkenyl group having 12 to 24 carbon atoms; and dialkenyldimethylammonium salt having an alkenyl group having 12 to 24 carbon atoms.

[0057] The anion of the quaternary ammonium salt is not particularly limited, but halogen ions such as fluoride ions, chloride ions, bromide ions, and iodide ions; hydroxide ions; and organic acid ions such as benzoate ions are preferred. Among these, halogen ions are preferred, and chloride ions are more preferred. The anion may be used alone or in combination of two or more types.

[0058] Suitable quaternary ammonium salts include butyltrimethylammonium salt, octyltrimethylammonium salt, dioctyldimethylammonium salt, decyltrimethylammonium salt, dodecyltrimethylammonium salt, didodecyldimethylammonium salt, tetradecyltrimethylammonium salt, hexadecyltrimethylammonium salt, stearyltrimethylammonium salt, coconut alkyltrimethylammonium salt, distearyldimethylammonium salt, oleyltrimethylammonium salt, dioleyldimethylammonium salt, and phenyltrimethylammonium chloride. Of these, coconut alkyltrimethylammonium salt, dioleyldimethylammonium salt, dodecyltrimethylammonium salt, and stearyltrimethylammonium salt are preferred, and coconut alkyltrimethylammonium salt and dioleyldimethylammonium salt are more preferred.

[0059] The amine salt can be any salt compound having primary to tertiary amino groups, such as alkylamine salts and polyallylamine salts. Examples of alkylamine salts include dodecylamine hydrochloride and octadecylamine hydrochloride. Examples of polyallylamine salts include polyallylamine hydrochloride, polyallylamine acetate, polyallylamine amide sulfate, copolymers of allylamine hydrochloride and diallylamine hydrochloride, copolymers of allylamine hydrochloride and dimethylallylamine hydrochloride, copolymers of allylamine acetate and diallylamine acetate, and copolymers of allylamine hydrochloride and other materials. Such polyallylamine salts preferably have a weight-average molecular weight of 1,000 to 30,000, more preferably 2,000 to 20,000, even more preferably 3,000 to 15,000, particularly preferably 2,500 to 10,000, and most preferably 3,000 to 10,000.

[0060] Examples of amphoteric surfactants include alkyl betaines and alkylamine oxides.

[0061] The polishing accelerator may be a commercially available product or a synthetic product. Furthermore, the polishing accelerator may be used alone or in a mixture of two or more types.

[0062] Here, it should be noted that the polishing accelerator is a surfactant other than the polyoxyalkylene alkyl ether used as the emulsifier. For example, if polyoxyethylene decyl ether with 10 moles of ethylene oxide added is used as the emulsifier, the polishing accelerator is a surfactant other than the polyoxyethylene decyl ether with 10 moles of ethylene oxide added. In this case, polyoxyethylene decyl ether with a different number of moles of ethylene oxide added (e.g., 8 moles), polyoxyethylene isodecyl ether with a different alkyl chain structure (i.e., isomer), and polyoxyethylene alkyl ether with a different alkyl chain length (e.g., polyoxyethylene tetradecyl ether) can all be used as polishing accelerators.

[0063] The content of the polishing accelerator in the polishing composition is preferably 0.01% by mass or more, more preferably 0.02% by mass or more, even more preferably 0.03% by mass or more, particularly preferably 0.05% by mass or more, even more preferably 0.07% by mass or more, and particularly preferably 0.08% by mass or more, based on the total mass (100% by mass) of the polishing composition. Furthermore, the content of the polishing accelerator in the polishing composition is preferably 5% by mass or less, more preferably 4% by mass or less, even more preferably 3% by mass or less, particularly preferably 2.5% by mass or less, and most preferably 2% by mass or less, based on the total mass of the polishing composition. According to one embodiment, the content of the polishing accelerator in the polishing composition is 0.01% by mass or more and 3.0% by mass or less, 0.05% by mass or more and 2.5% by mass or less, or 0.07% by mass or more and 2.0% by mass or less, based on the total mass (100% by mass) of the polishing composition. By having the polishing accelerator content within the above range, the affinity to the buff is improved during polishing, further enhancing the processing power.

[0064] In one embodiment, the polishing accelerator is a cationic surfactant. In this case, the content of the polishing accelerator (cationic surfactant) in the polishing composition is preferably 0.01% by mass or more, more preferably 0.02% by mass or more, even more preferably 0.03% by mass or more, particularly preferably 0.05% by mass or more, even more preferably 0.07% by mass or more, and particularly preferably 0.08% by mass or more, based on the total mass (100% by mass) of the polishing composition. Furthermore, the content of the polishing accelerator (cationic surfactant) in the polishing composition is preferably 1.5% by mass or less, more preferably 1.2% by mass or less, even more preferably 1.0% by mass or less, particularly preferably 0.9% by mass or less, and most preferably 0.8% by mass or less, based on the total mass of the polishing composition. In one embodiment, the cationic surfactant is contained in an amount of 0.01% by mass or more and 0.6% by mass or less, based on the total mass (100% by mass) of the polishing composition. By having the polishing accelerator (cationic surfactant) content within the above range, the affinity to the buff is improved during polishing, further enhancing the processing power.

[0065] In one embodiment, the polishing accelerator is an anionic surfactant. In this case, the content of the polishing accelerator (anionic surfactant) in the polishing composition is preferably 0.09% by mass or more, more preferably 0.10% by mass or more, even more preferably 0.15% by mass or more, particularly preferably 0.20% by mass or more, and even more preferably 0.25% by mass or more, based on the total mass (100% by mass) of the polishing composition. Furthermore, the content of the polishing accelerator (anionic surfactant) in the polishing composition is preferably 2.2% by mass or less, more preferably 2.0% by mass or less, even more preferably 1.8% by mass or less, and particularly preferably 1.5% by mass or less, based on the total mass of the polishing composition. By having the content of the polishing accelerator (anionic surfactant) within the above range, the affinity to the buff is improved during polishing, and the processing power is further improved.

[0066] In the polishing composition of this embodiment, the mass ratio of the emulsifier to the polishing accelerator (mass of emulsifier / mass of polishing accelerator) is preferably 0.5 to 50, more preferably 1 to 45, even more preferably 1.2 to 40, and particularly preferably 1.5 to 35. According to one embodiment, the mass ratio of the emulsifier to the polishing accelerator (mass of emulsifier / mass of polishing accelerator) is 2 to 35, 2 to 30, 2 to 25, 2 to 20, 3 to 35, 3 to 30, 3 to 25, 3 to 20, 4 to 35, 4 to 30, 4 to 25, or 4 to 20. By having the mass ratio of the emulsifier to the polishing accelerator within the above range, the affinity to the buff is improved during polishing, and the processing power is further improved.

[0067] [Hydrophobic dispersion medium] The polishing composition according to this embodiment includes a hydrophobic dispersion medium. The hydrophobic dispersion medium includes, for example, at least one selected from the group consisting of normal paraffinic hydrocarbons, isoparaffinic hydrocarbons, naphthenic hydrocarbons, and terpeneic hydrocarbons. Preferably, the vapor pressure of the hydrophobic dispersion medium at 20°C is 0.0001 kPa or more and 2 kPa or less. Therefore, according to one embodiment, the hydrophobic dispersion medium includes at least one selected from the group consisting of normal paraffinic hydrocarbons, isoparaffinic hydrocarbons, naphthenic hydrocarbons, and terpeneic hydrocarbons, and the vapor pressure of the hydrophobic dispersion medium at 20°C is 0.0001 kPa or more and 2 kPa or less. Hereinafter, normal paraffinic hydrocarbons, isoparaffinic hydrocarbons, naphthenic hydrocarbons, and terpeneic hydrocarbons that may be included in the hydrophobic dispersion medium may be referred to as "organic solvents".

[0068] The hydrophobic dispersion medium may consist of only one type of organic solvent, or it may be a mixture of two or more organic solvents. According to one embodiment, the hydrophobic dispersion medium includes at least two selected from the group consisting of normal paraffinic hydrocarbons, isoparaffinic hydrocarbons, naphthenic hydrocarbons, and terpene hydrocarbons.

[0069] In this embodiment, the hydrophobic dispersion medium and organic solvent are preferably those that do not readily dissolve in water. The hydrophobic dispersion medium and organic solvent may be commercially available or synthesized.

[0070] Normal paraffinic hydrocarbons, isoparaffinic hydrocarbons, naphthenic hydrocarbons, and terpeneic hydrocarbons are preferably derived from mineral oil, and may be extracted and purified from mineral oil-derived components, or they may be synthesized using mineral oil-derived components as raw materials (synthetic hydrocarbons derived from mineral oil). Normal paraffinic hydrocarbons, isoparaffinic hydrocarbons, naphthenic hydrocarbons, and terpeneic hydrocarbons are more preferably synthetic hydrocarbons derived from mineral oil.

[0071] Examples of normal paraffinic hydrocarbons include straight-chain hydrocarbons with approximately 5 to 30 carbon atoms, liquid paraffins, kerosene, and diesel fuel.

[0072] Examples of isoparaffinic hydrocarbons include branched hydrocarbons with 5 to 40 carbon atoms, and liquid isoparaffins.

[0073] Examples of naphthenic hydrocarbons include cyclic hydrocarbons with 5 to 40 carbon atoms, such as monocyclic cycloparaffins like cyclohexane, cyclopentane, and cyclononane; polycyclic cycloparaffins like decalin; and alkylcycloparaffins like methylcyclopentane, methylcyclohexane, 1-methyl-4-isopropylcyclohexane, butylcyclohexane, and methyldecalin.

[0074] Examples of terpene hydrocarbons include chain-like terpene hydrocarbons such as myrcene, farnesene, and citral; and cyclic terpene hydrocarbons such as menthol, cineole, pinene, limonene, α-terpinene, γ-terpinene, camphene, phellandrene, terpinene, terpinolene, p-cymene, and cedrene.

[0075] The hydrophobic dispersion medium may further contain other organic solvents other than the normal paraffinic hydrocarbons, isoparaffinic hydrocarbons, naphthenic hydrocarbons, and terpene hydrocarbons mentioned above. Hereinafter, organic solvents other than normal paraffinic hydrocarbons, isoparaffinic hydrocarbons, naphthenic hydrocarbons, and terpene hydrocarbons will be referred to as "other organic solvents." Examples of such other organic solvents include, for example, methyl alcohol, ethyl alcohol, isopropyl alcohol, acetone, diethyl ether, ethyl acetate, butyl acetate, triethyl citrate, acetyl tributyl citrate, and acetyl triethyl citrate.

[0076] The molecular weight of the hydrophobic dispersion medium is preferably 80 or more, more preferably 100 or more, even more preferably 120 or more, and particularly preferably 140 or more. The molecular weight of the hydrophobic dispersion medium is preferably 600 or less, more preferably 500 or less, even more preferably 450 or less, and particularly preferably 400 or less. When the molecular weight of the hydrophobic dispersion medium is within the above range, the hydrophobic dispersion medium can disperse the abrasive grains well, resulting in improved processing power and good polishing of the workpiece. The molecular weight of the hydrophobic dispersion medium is calculated from the average carbon number and molecular structure described in the SDS, etc., using the atomic weights defined by IUPAC.

[0077] Hydrophobic dispersions (organic solvents) generally have a flash point. The flash point is the lowest temperature at which a liquid, when heated to a constant temperature and a flame is brought near it, produces a vapor of the concentration necessary for instantaneous ignition. The flash point can also be described as the lowest temperature at which a hydrophobic dispersion can volatilize and form a flammable mixture with air. There are various methods for measuring the flash point, depending on the purpose of the measurement and the properties of the sample. Methods for measuring the flash point include the sealed method and the open method. Examples of sealed methods include the Tag sealed method (JIS K 2265-1:2007), the Seta sealed method (JIS K 2265-2:2007), and the Penn-Skier-Haltens sealed method (JIS K 2265-3:2007). Examples of open methods include the Cleveland open method (JIS K 2265-4:2007).

[0078] In the present invention, the hydrophobic dispersion medium preferably has a flash point of 30°C to 140°C, and more preferably 50°C to 120°C. When the flash point of the hydrophobic dispersion medium is within the above range, the volatility of the hydrophobic dispersion medium during polishing is appropriate, a liquid film is formed at the polishing interface with an appropriate thickness, and the intended effects of the present invention are further improved.

[0079] In the present invention, even when the hydrophobic dispersion medium contains two or more organic solvents, it is preferable that the flash point of the hydrophobic dispersion medium (FPI flash point described later) is 30°C or higher and 140°C or lower. In this specification, when the hydrophobic dispersion medium is composed of one organic solvent, the flash point of the hydrophobic dispersion medium means the flash point measured by any of the above methods. Also in this specification, when the hydrophobic dispersion medium contains two or more organic solvents, the flash point of the hydrophobic dispersion medium means the flash point calculated from the Flash-Point Blending Index (FPI) (hereinafter also referred to as the "FPI flash point").

[0080] The lower limit of the hydrophobic dispersion medium content in the polishing composition is preferably 0.5% by mass or more, more preferably 1% by mass or more, even more preferably 5% by mass or more, particularly preferably 10% by mass or more, and most preferably 15% by mass or more, based on the total mass (100% by mass) of the polishing composition. The upper limit of the hydrophobic dispersion medium content in the polishing composition is preferably 60% by mass or less, more preferably 55% by mass or less, even more preferably 50% by mass or less, particularly preferably 45% by mass or less, and most preferably 40% by mass or less, based on the total mass of the polishing composition. In other words, the hydrophobic dispersion medium content in the polishing composition is preferably 0.5% by mass or more and 60% by mass or less, more preferably 1% by mass or more and 55% by mass or less, even more preferably 5% by mass or more and 50% by mass or less, particularly preferably 10% by mass or more and 45% by mass or less, and most preferably 15% by mass or more and 40% by mass, based on the total mass of the polishing composition. In a preferred embodiment of the present invention, the content of the hydrophobic dispersion medium is 15% by mass or more and 40% by mass or less, relative to the total mass of the polishing composition. By having the hydrophobic dispersion medium content within this range, the processing power is improved, and the workpiece can be polished effectively in both rough and finish polishing.

[0081] The content of the hydrophobic dispersion medium in the polishing composition is preferably 0.01 mol / kg or more, more preferably 0.05 mol / kg or more, even more preferably 0.1 mol / kg or more, particularly preferably 0.2 mol / kg or more, and most preferably 0.3 mol / kg or more, based on the total mass of the polishing composition. According to one embodiment, the content of the hydrophobic dispersion medium in the polishing composition is 0.5 mol / kg or more, based on the total mass of the polishing composition. Furthermore, the content of the hydrophobic dispersion medium in the polishing composition is preferably 10.0 mol / kg or less, more preferably 5.0 mol / kg or less, even more preferably 3.0 mol / kg or less, particularly preferably 2.0 mol / kg or less, and most preferably 1.5 mol / kg or less, based on the total mass of the polishing composition. By having the content of the hydrophobic dispersion medium within the above range, the processing power is further improved.

[0082] [water] The polishing composition according to this embodiment contains water. From the viewpoint of suppressing interference with the action of other components, water that contains as few impurities as possible is preferred. Specifically, pure water, ultrapure water, or distilled water obtained by removing impurity ions with an ion exchange resin and then removing foreign matter through a filter is preferred.

[0083] The lower limit of the water content in the polishing composition is preferably 1% by mass or more, more preferably 5% by mass or more, even more preferably 10% by mass or more, particularly preferably 15% by mass or more, and most preferably 20% by mass or more, based on the total mass of the polishing composition. The upper limit of the water content in the polishing composition is preferably 90% by mass or less, more preferably 85% by mass or less, even more preferably 80% by mass or less, particularly preferably 75% by mass or less, and most preferably 70% by mass or less, based on the total mass of the polishing composition. In other words, the water content in the polishing composition is preferably 1% by mass or more and 90% by mass or less, more preferably 5% by mass or more and 85% by mass or less, even more preferably 10% by mass or more and 80% by mass or less, particularly preferably 15% by mass or more and 75% by mass or less, and most preferably 20% by mass or more and 70% by mass or less, based on the total mass of the polishing composition. By having the water content within the above range, the processing power is improved and the workpiece can be polished well in both rough polishing and finish polishing.

[0084] [Thickener] The polishing composition according to this embodiment may contain a thickening agent. The thickening agent helps to uniformly disperse the abrasive particles in the polishing composition and helps to act efficiently on the object to be polished during polishing.

[0085] Examples of thickeners include polymer compounds such as synthetic thickeners like poly(meth)acrylic compounds (meth)acrylic compounds such as poly(meth)acrylic acid and sodium poly(meth)acrylate, and urethane compounds; cellulosic thickeners (semi-synthetic thickeners) such as carboxymethylcellulose and carboxyethylcellulose; and natural thickeners such as agar, carrageenan, layered silicate compounds, xanthan gum, and gum arabic.

[0086] Examples of (meth)acrylic compounds include fully neutralized, partially neutralized, or alkali-soluble poly(meth)acrylic acid ((meth)acrylic polymer). Among these, alkali-soluble poly(meth)acrylic acid is preferred. Alkali-soluble poly(meth)acrylic acid is also called an alkali-soluble thickener and generally consists mainly of a high molecular weight polymer (i.e., poly(meth)acrylic acid) with a large number of acidic groups such as carboxyl groups. By adjusting the pH to a neutral to alkaline range with an alkaline agent, it forms a network structure and exhibits a thickening effect. In this invention, alkali-soluble poly(meth)acrylic acid (alkali-soluble poly(meth)acrylic acid thickener) also includes alkali-swelling poly(meth)acrylic acid (alkali-swelling poly(meth)acrylic acid thickener).

[0087] Therefore, the (meth)acrylic compounds used as thickeners are alkali-soluble thickeners, that is, thickeners that thicken by solubilizing the polymer with alkali at the time of use. There are ASE (Alkali Soluble Emulsion) types that do not have an associative group (e.g., a hydrophobic group) and HASE (Hydrophobically modified AlkaliSoluble Emulsion) types that have an associative group (e.g., a hydrophobic group) to enhance the thickening power, and the HASE type with an associative group to enhance the thickening power is preferred.

[0088] When using alkali-soluble (meth)acrylic compounds as thickeners, poly(meth)acrylic acid and an alkali are used in combination. Examples of alkalis include inorganic alkalis such as sodium hydroxide, potassium hydroxide, and ammonia, and organic alkalis such as triethanolamine. By adding an alkali, poly(meth)acrylic acid exhibits a thickening effect. Furthermore, the thickener may be a Newtonian fluid or a non-Newtonian fluid.

[0089] The amount of thickener in the polishing composition is preferably 0.1% by mass or more, and more preferably 0.5% by mass or more, based on the total mass of the polishing composition. Furthermore, the amount of thickener in the polishing composition is preferably 3.0% by mass or less, and more preferably 2.0% by mass or less, based on the total mass of the polishing composition. When the amount of thickener is within the above range, the viscosity of the polishing composition is improved, and dripping of the polishing composition liquid can be suppressed on vertical surfaces such as the body of a car door.

[0090] [Additives] The polishing composition according to this embodiment preferably contains additives other than the above-mentioned components. Specific examples of such additives include, for example, emulsifying stabilizers and pH adjusters. These additives may be used individually or in combination of two or more. Adding these additives improves the stability of the emulsion.

[0091] Examples of emulsifying stabilizers include polyhydric alcohols such as glycerin, ethylene glycol, and propylene glycol, and aliphatic alcohols such as cetyl alcohol and stearyl alcohol.

[0092] The additive content in the polishing composition is preferably 0.1% by mass or more, and more preferably 1.0% by mass or more. Furthermore, the additive content in the polishing composition is preferably 12.0% by mass or less, and more preferably 8.0% by mass or less. When the additive content is within the above range, the stability of the emulsion in the polishing composition increases. The additive content is the total mass of the additive components.

[0093] [pH of abrasive composition] The polishing composition of this embodiment is not particularly limited, but the pH can be adjusted by adding an acid or a salt thereof, or a base or a salt thereof, as described later. In one embodiment, the pH of the polishing composition is preferably pH 4 to 12, more preferably pH 5 to 11, even more preferably pH 6 to 10, and particularly preferably pH 7 to 10.

[0094] [Acid or its salt] The polishing composition of this embodiment may contain an acid or a salt thereof as a pH adjuster.

[0095] Both inorganic and organic acids can be used as the acid. Examples of inorganic acids include hydrochloric acid, sulfuric acid, nitric acid, hydrofluoric acid, boric acid, carbonic acid, hypophosphorous acid, phosphorous acid, and phosphoric acid. Examples of organic acids include formic acid, acetic acid, propionic acid, butyric acid, valeric acid, 2-methylbutyric acid, n-hexanoic acid, 3,3-dimethylbutyric acid, 2-ethylbutyric acid, 4-methylpentanoic 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, lactic acid, diglycolic acid, 2-furanic acid, 2,5-franic acid, 3-furanic acid, 2-tetrahydrofuranic acid, methoxyacetic acid, methoxyphenylacetic acid, phenoxyacetic acid, methanesulfonic acid, ethanesulfonic acid, sulfosuccinic acid, benzenesulfonic acid, toluenesulfonic acid, phenylphosphonic acid, and hydroxyethane-1,1-diphosphonic acid. Furthermore, examples of salts include group 1 element salts, group 2 element salts, aluminum salts, ammonium salts, amine salts, and quaternary ammonium salts. These acids or their salts can be used individually or in combination of two or more. Among these, nitric acid and citric acid are preferred.

[0096] [Base or its salt] The polishing composition of this embodiment may contain a base or a salt thereof as a pH adjuster. Examples of bases or salts thereof include amines such as aliphatic amines and aromatic amines, organic bases such as quaternary ammonium hydroxide, alkali metal hydroxides such as sodium hydroxide and potassium hydroxide, hydroxides of group 2 elements such as magnesium hydroxide and calcium hydroxide, and ammonia.

[0097] [Other ingredients] The polishing composition of this embodiment may further contain, if necessary, an oxidizing agent that oxidizes the surface of the object to be polished, a water-soluble polymer other than the thickening agent that acts on the surface of the object to be polished or the surface of the abrasive grains, a corrosion inhibitor or chelating agent that suppresses corrosion of the object to be polished, and other functional preservatives, fungicides, polymer materials, and other components.

[0098] Examples of oxidizing agents include hydrogen peroxide, peracetic acid, percarbonates, urea peroxide, perchlorates, and persulfates.

[0099] Examples of water-soluble polymers other than the thickeners mentioned above include polyphosphonic acid, polystyrene sulfonic acid and other polysulfonic acids, polyethylene glycol, polyvinyl alcohol, polyvinylpyrrolidone, alkylol ammonium salts, and oxyalkylene polymers having one or more types of oxyalkylene units. Salts of the above compounds can also be suitably used as water-soluble polymers.

[0100] Examples of corrosion inhibitors include amines, pyridines, tetraphenylphosphonium salts, benzotriazoles, triazoles, tetrazoles, and benzoic acid. Examples of chelating agents include carboxylic acid chelating agents such as gluconic acid, amine chelating agents such as ethylenediamine, diethylenetriamine, and trimethyltetraamine, polyaminopolycarbonate chelating agents such as ethylenediaminetetraacetic acid, nitrilotriacetic acid, hydroxyethylethylenediaminetriacetic acid, triethylenetetraminehexaacetic acid, and diethylenetriaminepentaacetic acid, organic phosphonic acid chelating agents such as 2-aminoethylphosphonic acid, 1-hydroxyethylidene-1,1-diphosphonic acid, aminotri(methylenephosphonic acid), ethylenediaminetetrakis(methylenephosphonic acid), diethylenetriaminepenta(methylenephosphonic acid), ethane-1,1-diphosphonic acid, ethane-1,1,2-triphosphonic acid, methanehydroxyphosphonic acid, and 1-phosphonovutane-2,3,4-tricarboxylic acid, as well as phenol derivatives and 1,3-diketones.

[0101] Examples of preservatives include sodium hypochlorite. Examples of antifungal agents include oxazolidine-2,5-dione and other oxazolines.

[0102] [Viscosity of abrasive compositions] The viscosity of the polishing composition of this embodiment is preferably 500 mPa·s or more and 1,000,000 mPa·s or less at 25°C, more preferably 800 mPa·s or more and 500,000 mPa·s or less, even more preferably 1,000 mPa·s or more and 300,000 mPa·s or less, particularly preferably 1,500 mPa·s or more and 10,000 mPa·s or less, and most preferably 2,000 mPa·s or more and 5,000 mPa·s or less. In one embodiment, the viscosity of the polishing composition is 1,000 mPa·s to 150,000 mPa·s, 1,000 mPa·s to 50,000 mPa·s, 1,000 mPa·s to 300,000 mPa·s, 1,000 mPa·s to 15,000 mPa·s, or 1,000 mPa·s to 10,000 mPa·s. The viscosity of the polishing composition can be measured using a B-type viscometer, and specifically, the value measured by the method described in the examples is adopted.

[0103] [Method for producing abrasive compositions] The method for producing the polishing composition of this embodiment includes the step of mixing abrasive grains, an emulsifier, a polishing accelerator, water, and a hydrophobic dispersion medium. By such a production method, a polishing composition that can achieve the intended effects of the present invention can be produced. In other words, the present invention also provides a method for producing a polishing composition.

[0104] In the method for producing the polishing composition of this embodiment, it is preferable to include a step of classifying the components of the polishing composition into hydrophilic components and hydrophobic components, and preparing a hydrophilic mixture containing hydrophilic components and a hydrophobic mixture containing hydrophobic components separately. Therefore, the method for producing the polishing composition of this embodiment includes the steps of: mixing water and, if necessary, a hydrophilic component such as an emulsifying stabilizer to obtain a hydrophilic mixture; mixing a hydrophobic dispersion medium, an emulsifier, a polishing accelerator, and, if necessary, a hydrophobic component such as an oil to obtain a hydrophobic mixture; mixing the hydrophilic mixture and the hydrophobic mixture and emulsifying them to obtain a dispersion; and mixing abrasive particles into the dispersion to obtain a polishing composition.

[0105] Here, the polishing accelerator may be included in the hydrophobic mixture beforehand, or it may be added to the emulsion obtained after emulsifying the hydrophilic mixture and the hydrophobic mixture. According to this manufacturing method, the polishing composition is made by adding the polishing accelerator to an emulsion in which micelles (aggregates) are formed with a hydrophobic dispersion medium, an emulsifier, and water, and the polishing accelerator does not participate in micelle formation in the polishing composition. That is, it is presumed that the polishing accelerator is in a free state in the polishing composition. As a result, the polishing accelerator can act more efficiently on the object to be polished, and the processing force can be further increased. Therefore, according to one embodiment, the polishing composition is made by adding abrasive grains and a polishing accelerator to an emulsion in which micelles are formed with a hydrophobic dispersion medium, an emulsifier, and water.

[0106] In other words, the method for producing the polishing composition of this embodiment includes the steps of: mixing a hydrophobic dispersion medium, an emulsifier, and water to emulsify and obtain an emulsion; and mixing a polishing accelerator and abrasive grains into the emulsion to obtain a polishing composition. More specifically, the method for producing the polishing composition of this embodiment includes the steps of: mixing water and, if necessary, a hydrophilic component such as an emulsifying stabilizer to obtain a hydrophilic mixture; mixing a hydrophobic dispersion medium, an emulsifier, and, if necessary, a hydrophobic component such as an oil to obtain a hydrophobic mixture; mixing the hydrophilic mixture and the hydrophobic mixture to emulsify and obtain an emulsion; and mixing a polishing accelerator and abrasive grains into the emulsion to obtain a polishing composition.

[0107] In each of the above steps, the temperature when mixing each component is not particularly limited, but 10°C to 40°C is preferred. The mixing time is also not particularly limited. The emulsification conditions for obtaining the emulsion can be determined by applying the necessary shear force using an emulsification means such as a homomixer or homogenizer to emulsify the hydrophilic mixture and the hydrophobic mixture. The temperature during emulsification is preferably 10°C to 40°C, and the mixing time is not particularly limited, but for example, 1 minute to 30 minutes. After mixing the abrasive grains, emulsifier, polishing accelerator, hydrophobic dispersion medium and water, other components such as pH adjusters and preservatives may be stirred and mixed as needed to obtain the polishing composition of this embodiment.

[0108] [Object to be polished] The object to be polished according to this embodiment is not particularly limited, but preferably includes at least one selected from the group consisting of alloy materials, resin materials, metals, metalloids, metal oxides, metal carbides, metal nitrides, metalloid oxides, metalloid carbides, metalloid nitrides, and glass materials, and may also be a composite material of these materials. Resin materials used for painted surfaces such as automobile bodies are particularly preferred.

[0109] The following describes alloy materials, resin materials, metals, metalloids, and their oxides, carbides, and nitrides, as well as glass materials.

[0110] [Alloy material] Alloy materials are covalent materials in which one or more different metal elements, or nonmetallic elements such as carbon, nitrogen, and silicon, are shared with a main metal element. They are manufactured with the aim of improving properties such as mechanical strength, chemical resistance, corrosion resistance, and heat resistance compared to pure metals.

[0111] Alloy materials are named based on the type of metal that constitutes the main component. Examples of alloy materials include aluminum alloys, iron alloys, titanium alloys, nickel alloys, and copper alloys. These alloy materials may be used individually or in combination of two or more. In particular, it is preferable to include at least one selected from the group consisting of aluminum alloys and iron alloys. Furthermore, it is preferable to have alloy materials in which the Vickers hardness (HV) of the main component metal and a different metal differs by 5 or more. Aluminum alloys are lightweight and have excellent strength, so they are used in a variety of applications, including structural materials such as building materials and containers, transportation equipment such as automobiles, ships and aircraft, as well as various electrical appliances and electronic components. Titanium alloys are lightweight and have excellent corrosion resistance, so they are widely used in precision instruments, ornaments, tools, sporting goods, medical components, etc. Stainless steel and nickel alloys, which are iron alloys, have excellent corrosion resistance, so they are used in a variety of applications, including structural materials and transportation equipment, as well as tools, machinery and equipment, and cooking utensils. Furthermore, copper alloys are widely used in decorative items, tableware, musical instruments, and electrical components due to their excellent electrical conductivity, thermal conductivity, corrosion resistance, ease of processing, and beautiful finish. Recently, materials containing resins have also been used in the aforementioned applications.

[0112] Aluminum alloys primarily consist of aluminum, and preferably contain at least one other metal species selected from the group consisting of magnesium, silicon, copper, zinc, manganese, chromium, and iron. While there is no particular lower limit to the content of the other metal species in the aluminum alloy, it is preferably 0.1% by mass or more relative to the total aluminum alloy. Furthermore, while there is no particular upper limit to the content of the other metal species in the aluminum alloy, it is preferably 10% by mass or less relative to the total aluminum alloy.

[0113] Specific examples of aluminum alloys include, for example, those listed in JIS H4000:2006, such as Al-Cu and Al-Cu-Mg alloys in the 2000s, Al-Mn alloys in the 3000s, Al-Si alloys in the 4000s, Al-Mg alloys in the 5000s, Al-Mg-Si alloys in the 6000s, Al-Zn-Mg alloys in the 7000s, and Al-Fe-Mn alloys in the 8000s.

[0114] Iron alloys primarily consist of iron, and preferably contain at least one other metal species selected from the group consisting of chromium, nickel, molybdenum, and manganese. The lower limit of the content of the other metal species in the iron alloy is not particularly limited, but it is preferably 10% by mass or more relative to the total iron alloy. The upper limit of the content of the other metal species in the iron alloy is also not particularly limited, but it is preferably 50% by mass or less relative to the total iron alloy.

[0115] The iron alloy is preferably stainless steel. Specific examples of stainless steel include, for example, SUS201, SUS303, 303Se, SUS304, SUS304L, SUS304NI, SUS305, SUS305JI, SUS309S, SUS310S, SUS316, SUS316L, SUS321, SUS347, SUS384, SUSXM7, SUS303F, SUS303C, SUS430, SUS430F, SUS434, SUS410, SUS416, SUS420J1, SUS420J2, SUS420F, SUS420C, SUS631J1, etc., according to the type symbols listed in JIS G4303:2005.

[0116] Titanium alloys are primarily composed of titanium and contain other metal species such as aluminum, iron, and vanadium. The content of these other metal species in the titanium alloy is, for example, between 3.5% and 30% by mass relative to the total weight of the titanium alloy. Examples of titanium alloys include those classified as types 11-23, 50, 60, 61, and 80 in JIS H4600:2012.

[0117] Nickel alloys are primarily composed of nickel and contain at least one other metal species selected from, for example, iron, chromium, molybdenum, and cobalt. The content of the other metal species in the nickel alloy is, for example, 20% to 75% by mass relative to the total nickel alloy. Examples of nickel alloys include NCF600, 601, 625, 750, 800, 800H, 825, NW0276, 4400, 6002, and 6022, according to the alloy numbers listed in JIS H4551:2000.

[0118] Copper alloys primarily consist of copper and contain at least one other metal species selected from, for example, iron, lead, zinc, and tin. The content of the other metal species in the copper alloy is, for example, 3% by mass or more and 50% by mass or less of the total copper alloy. Examples of copper alloys include C2100, 2200, 2300, 2400, 2600, 2680, 2720, 2801, 3560, 3561, 3710, 3713, 4250, 4430, 4621, 4640, 6140, 6161, 6280, 6301, 7060, 7150, 1401, 2051, 6711, and 6712, according to the alloy numbers listed in JIS H3100:2006.

[0119] [Resin materials] The type of resin material is not particularly limited and may be either a thermosetting resin or a thermoplastic resin.

[0120] Examples of thermosetting resins include epoxy resins, polyimide resins, phenolic resins, amino resins, unsaturated polyester resins, thermosetting polyurethane resins, and melamine resins.

[0121] Examples of thermoplastic resins include polystyrene resin, acrylonitrile-butadiene-styrene copolymer resin (ABS resin), (meth)acrylic resin (methacrylic and / or acrylic resin), organic acid vinyl ester resin or its derivatives, vinyl ether resin, halogen-containing resins such as polyvinyl chloride, polyvinylidene chloride, and polyvinylidene fluoride, olefin resins such as polyethylene and polypropylene, polycarbonate resin, saturated polyester resins such as polyethylene terephthalate and polyethylene naphthalate, polyamide resin, thermoplastic polyurethane resin, polysulfone resin (polyethersulfone, polysulfone, etc.), polyphenylene ether resin (polymers of 2,6-xylenol, etc.), cellulose derivatives (cellulose esters, cellulose carbamates, cellulose ethers, etc.), and silicone resins (polydimethylsiloxane, polymethylphenylsiloxane, etc.).

[0122] The above resins can be used individually or in combination of two or more. Among these resins, thermoplastic resins are preferred from the viewpoint of impact resistance and weather resistance, and polycarbonate resins are more preferred.

[0123] The object to be polished, which includes a resin material, may be in the form of a component formed from a resin material (resin component), or a composite material having a resin coating on the surface of a metal substrate, etc., and is not particularly limited. Examples of resins used for the coating include thermosetting polyurethane resin, (meth)acrylic resin, polyester resin, etc. The resin coating may be a transparent clear coating. Furthermore, the polishing composition according to the present invention is preferably used for resin coatings with a pencil hardness of preferably 5H or less, more preferably 3H or less, particularly preferably H or less, and most preferably F or less, as measured by the pencil method described in JIS K 5600-5-4 (1999).

[0124] The composite material having a resin coating is not particularly limited, but one example is a three-dimensional resin material. Examples of applications for three-dimensional resin materials include automobile bodies, railway vehicles, aircraft, and resin components. The resin coating applied to the surface of an automobile body has a large surface area and is curved, and the polishing composition of this embodiment is suitable for polishing the outer surface of such a resin coating.

[0125] [Metals, metalloids, and their oxides, carbides, and nitrides] Examples of metals include aluminum, iron, zirconium, copper, nickel, gold, silver, bismuth, manganese, and zinc.

[0126] Examples of metalloids include group IV semiconductors such as silicon (Si) and germanium (Ge), group II-VI compound semiconductors such as zinc selenide (ZnSe), cadmium sulfide (CdS), and zinc oxide (ZnO), group III-V compound semiconductors such as gallium arsenide (GaAs), indium phosphide (InP), and gallium nitride (GaN), group IV compound semiconductors such as silicon carbide (SiC) and silicon germanium (SiGe), and chalcopyrite semiconductors such as copper-indium-selenium (CuInSe2).

[0127] Furthermore, it can be suitably used for oxides, carbides, and nitrides of these materials.

[0128] [Glass materials] Examples of glass materials include blue plate glass, quartz glass, tempered glass, crystallized glass, aluminosilicate glass, and glassy carbon.

[0129] [Polishing method] As described above, the polishing composition of this embodiment is suitably used for polishing objects containing alloy materials, resin materials, metals, metalloids, metal oxides, metal carbides, metal nitrides, metalloid oxides, metalloid carbides, metalloid nitrides, or glass materials, as well as composite materials of these materials. Therefore, according to one embodiment, the object to be polished includes at least one selected from the group consisting of resin materials, alloy materials, and glass materials.

[0130] The polishing composition of this embodiment is suitable for polishing objects having a curved surface to be polished (for example, the painted surface of an automobile or the like). Therefore, the present invention also provides a polishing method that includes a polishing step of polishing an object to be polished using the polishing composition of this embodiment. Furthermore, according to this polishing method, a polishing method is also provided in which the object to be polished is a painted surface and the painted surface is polished with a wool buff and / or a sponge buff. According to one embodiment, the polishing step includes supplying the polishing composition to the surface of the object to be polished and polishing by bringing a polishing buff into contact with the surface to which the polishing composition has been supplied. According to another embodiment, a polishing method is provided in which the painted surface is polished using the polishing composition of this embodiment, preferably with a wool buff. According to yet another embodiment, a polishing method is provided in which the painted surface is polished using the polishing composition of this embodiment with a sponge buff.

[0131] Below, as an example of the polishing method of this embodiment, a method for polishing a resin-coated surface will be described. The configuration of the polishing apparatus is not particularly limited, and general polishing devices such as handheld polishers, single-sided polishing machines, double-sided polishing machines, and lens polishing machines may be used, as well as the automatic polishing apparatus described in Figure 1 of International Publication No. 2019 / 066014 (the polishing pad 10 in Figure 1 corresponds to the polishing buff).

[0132] For example, the polishing method of this embodiment may be applied when a polishing buff is attached to the tip of a hand polisher and a polishing operator manually moves the hand polisher to polish a resin-coated surface. The driving means of the hand polisher is not particularly limited, but generally single-action, double-action, gear-action, etc. are used, and single-action and double-action are preferred for polishing painted materials.

[0133] When polishing an object to be polished, such as an alloy material, using the polishing composition of this embodiment, the process can be carried out using the same equipment and conditions as those used for ordinary metal polishing. In a single-sided polishing apparatus, the object to be polished (preferably a substrate-shaped object) is held using a holder called a carrier, and one side of the object is polished by supplying the polishing composition while pressing a platen with an abrasive cloth attached to it against one side of the object and rotating the platen. In a double-sided polishing apparatus, the object to be polished is held using a holder called a carrier, and both sides of the object are polished by supplying the polishing composition from above while pressing a platen with an abrasive cloth attached to the opposing side of the object and rotating them in relative directions. At this time, polishing is performed by the physical action of friction between the polishing pad and the polishing composition and the object to be polished, and by the chemical action that the polishing composition has on the object to be polished.

[0134] In the polishing method according to this embodiment, the polishing load is one of the polishing conditions. Generally, the higher the load, the greater the frictional force from the abrasive grains, which improves the mechanical processing force and thus increases the polishing speed. The lower limit of the polishing load in the polishing method according to this embodiment is not particularly limited, but is 10 g / cm². 2 Preferably, it is 18 g / cm³ or more. 2 It is more preferable that the above conditions are met. As the polishing load increases, the mechanical processing characteristics improve, and therefore the polishing speed increases. The upper limit of the polishing load is 1000 g / cm². 2 Preferably, it is 500 g / cm³. 2 The following is more preferable: As the polishing load decreases, surface roughness of the polished surface is suppressed.

[0135] Furthermore, the polishing conditions in the polishing method according to this embodiment include the linear velocity during polishing (polishing linear velocity). Generally, the rotation speed of the polishing pad, the rotation speed of the carrier, the size of the object to be polished, the number of objects to be polished, etc., affect the linear velocity. However, when the linear velocity is high, the frictional force applied to the object to be polished increases, making it easier for the object to be polished mechanically. Also, frictional heat is generated due to friction, which can increase the chemical effect of the polishing composition. The lower limit of the polishing linear velocity in the polishing method according to this embodiment is not particularly limited, but it is preferably 10 m / min or more, and more preferably 20 m / min or more. The upper limit of the polishing linear velocity is preferably 1000 m / min or less, and more preferably 500 m / min or less. Within this range, a sufficiently high polishing speed can be obtained, and an appropriate frictional force can be applied to the object to be polished. That is, in this embodiment, the polishing linear velocity is preferably 10 m / min or more and 1000 m / min or less, and more preferably 20 m / min or more and 500 m / min or less.

[0136] The polishing composition of this embodiment may be used in a single-step process, or in one or more steps of a multi-step polishing process. For example, when used in a three-step polishing process, it can be used in one or more of the following steps: the first step (rough polishing), the second step (medium polishing), and the third step (finishing polishing).

[0137] When polishing an object using the polishing composition of this embodiment, the polishing composition used once can be recovered and reused for polishing. One example of a method for reusing the polishing composition is to recover the polishing composition discharged from the polishing device into a tank and recirculate it back into the polishing device for reuse. Reusing the polishing composition is useful because it reduces the environmental burden by decreasing the amount of polishing composition discharged as waste liquid, and it reduces the manufacturing cost of polishing the object by reducing the amount of polishing composition used.

[0138] When the polishing composition of this embodiment is used in a circulating manner, some or all of the abrasive particles and other additives consumed or lost during polishing can be added as a composition adjuster during the circulating use. In this case, the composition adjuster may be a mixture of some or all of the abrasive particles and other additives in any mixing ratio. By adding the composition adjuster, the polishing composition is adjusted to a composition suitable for reuse, and polishing is suitably maintained. The concentration of abrasive particles and other additives contained in the composition adjuster is arbitrary and not particularly limited, but it is preferable to adjust it appropriately according to the size of the circulation tank and polishing conditions.

[0139] The polishing composition of this embodiment may be a one-component type or a multi-component type, including a two-component type. Furthermore, the polishing composition of this embodiment may be prepared by diluting the undiluted polishing composition with a diluent such as water or oil, for example, 10 times or more.

[0140] The polishing buff used in the polishing method using the polishing composition of this embodiment may be made of a material such as wool, polyurethane, foamed polyurethane, nonwoven fabric, or suede.

[0141] While embodiments of the present invention have been described in detail, these are descriptive and illustrative, and not limiting, and it is clear that the scope of the present invention should be interpreted by the appended claims.

[0142] The present invention encompasses the following embodiments and forms.

[0143] [1] comprising abrasive grains, an emulsifier, a polishing accelerator, a hydrophobic dispersion medium, and water, The emulsifier is a polyoxyalkylene alkyl ether. The polishing accelerator is a surfactant (however, it is a surfactant different from the emulsifier) ​​in an abrasive composition.

[0144] [2] The polishing composition according to [1] above, wherein the abrasive grains and the polishing accelerator are added to an emulsion in which micelles are formed by the hydrophobic dispersion medium, the emulsifier and the water.

[0145] [3] The polishing composition according to [1] or [2] above, wherein the polishing accelerator is contained in an amount of 0.01% by mass or more and 3.0% by mass or less based on the total mass of the composition.

[0146] [4] The polishing accelerator is an abrasive composition according to any one of [1] to [3] above, comprising an ionic surfactant.

[0147] [5] The polishing composition according to any one of [1] to [4] above, wherein the polishing accelerator is a quaternary ammonium salt or an amine salt.

[0148] [6] The polishing composition according to any one of [1] to [5] above, wherein the polishing accelerator is one or more selected from the group consisting of carboxylates, sulfonates, sulfates, and phosphates.

[0149] [7] The polishing composition according to any one of [1] to [6] above, wherein the polishing accelerator is contained in an amount of 0.01% by mass or more and 0.6% by mass or less based on the total mass of the composition.

[0150] [8] The polishing composition according to any one of [1] to [7] above, wherein the mass ratio of the emulsifier to the polishing accelerator (mass content of emulsifier / mass content of polishing accelerator) is 2 or more and 35 or less.

[0151] [9] The emulsifier is a polyoxyethylene alkyl ether having an alkyl group with 8 to 12 carbon atoms, The abrasive composition according to any one of [1] to [8] above, wherein the emulsifier is present in an amount of 2.0 mol% or more when the molar content of the hydrophobic dispersion medium is 100 mol%.

[0152]

[10] The hydrophobic dispersion medium is the polishing composition according to any one of [1] to [9] above, wherein the vapor pressure at 20°C is 0.0001 kPa or more and 2 kPa or less.

[0153]

[11] The hydrophobic dispersion medium comprises at least one selected from the group consisting of normal paraffinic hydrocarbons, isoparaffinic hydrocarbons, naphthenic hydrocarbons, and terpene hydrocarbons. The polishing composition according to any one of [1] to

[10] above, wherein the vapor pressure of the hydrophobic dispersion medium at 20°C is 0.0001 kPa or more and 2 kPa or less.

[0154]

[12] The abrasive composition according to any one of [1] to

[11] above, wherein the hydrophobic dispersion medium comprises at least two selected from the group consisting of normal paraffinic hydrocarbons, isoparaffinic hydrocarbons, naphthenic hydrocarbons, and terpene hydrocarbons.

[0155]

[13] The polishing composition according to any one of [1] to

[12] above, wherein the flash point of the hydrophobic dispersion medium is 50°C or higher and 120°C or lower.

[0156]

[14] The abrasive composition according to any one of [1] to

[13] above, wherein the hydrophobic dispersion medium is contained in an amount of 15% by mass or more and 40% by mass or less based on the total mass of the abrasive composition.

[0157]

[15] The polishing composition according to any one of [1] to

[14] above, wherein the abrasive grains are aluminum oxide.

[0158]

[16] The abrasive grains are contained in an amount of 5% by mass or more and 45% by mass or less based on the total mass of the abrasive composition, as described in any of [1] to

[15] above.

[0159]

[17] A step of mixing a hydrophobic dispersion medium, an emulsifier, and water to emulsify and obtain an emulsion; The process involves mixing an abrasive accelerator and abrasive particles into the aforementioned emulsion to obtain an abrasive composition; A method for producing an abrasive composition containing [the specified ingredient].

[0160]

[18] A polishing method for polishing an object to be polished using any of the polishing compositions described in [1] to

[16] above.

[0161]

[19] The polishing method according to

[18] above, wherein the object to be polished includes at least one selected from the group consisting of resin material, alloy material, and glass material.

[0162]

[20] The polishing method according to

[18] or

[19] above, wherein the object to be polished is a painted surface, and the painted surface is polished with a wool buff and / or a sponge buff. [Examples]

[0163] The present invention will be described in more detail using the following examples and comparative examples. However, the technical scope of the present invention is not limited to the following examples. Unless otherwise specified, "%" and "parts" mean "mass%" and "parts by mass," respectively. In addition, in the following examples, unless otherwise specified, the operations were carried out under conditions of room temperature (20°C to 25°C) and relative humidity of 30%RH to 50%RH.

[0164] <About each ingredient> The abrasive particles, hydrophobic dispersion medium, emulsifier (polyoxyalkylene alkyl ether), and polishing accelerator used in the following examples and comparative examples were as follows.

[0165] [Abrasive grains] The following abrasive materials were used: Aluminum oxide: 96% gelatinization rate, average primary particle size 0.18 μm.

[0166] The alpha-gelatinization rate of aluminum oxide particles was measured using an X-ray analyzer (Ultima-IV, manufactured by Rigaku Corporation), with alpha-alumina particles, which had undergone sufficient alpha-gelatinization at a sufficiently high firing temperature, used as the reference material. The integrated intensity of the (113) plane diffraction lines obtained by X-ray diffraction measurements of the reference material and the target abrasive grains (aluminum oxide particles) was measured, and the alpha-gelatinization rate of the target abrasive grains (aluminum oxide particles) was calculated from the ratio of the integrated intensity of the (113) plane diffraction lines of the target abrasive grains to that of the reference material.

[0167] The average primary particle size of the abrasive grains was calculated from the specific surface area of ​​the abrasive grains and the density of the abrasive grains, measured using the BET method with "Macsorb HM Model-1201" manufactured by Mountec Co., Ltd.

[0168] The average secondary particle size (D50) of the abrasive grains was measured using the laser diffraction and scattering method with a MicrotracMT3300EXII (manufactured by Microtrac-Bell Co., Ltd.).

[0169] Particle size was measured using laser diffraction and scattering methods under the following equipment and conditions, following the measurement procedures (1) and (2) below.

[0170] Measuring instrument: Laser diffraction / scattering particle size distribution analyzer "MicrotracMT3300EXII" (manufactured by Microtrac-Bell Co., Ltd.) Measurement conditions: Circulation flow rate "0.42 L / min or more and 0.84 L / min or less" The refractive index of water is 1.33. The refractive index of abrasive grains (alumina) is "1.77". Sample circulator: "USVR" (manufactured by Microtrac-Bell Corporation) Ultrasonic disperser: "Ultrasonic homogenizer US-50E" (manufactured by Nippon Seiki Seisakusho Co., Ltd.).

[0171] Measurement procedure: (1) Measure out 0.5 mL of the polishing composition and dilute it 100 times with pure water. (2) Using the diluted sample described above, the sample is introduced into a circulator to reach the optimal concentration range. After circulating the sample for 1 minute while it is subjected to ultrasonic dispersion treatment (oscillation frequency: 28 kHz) using an ultrasonic disperser, the measurement is performed, and the obtained value is defined as the average secondary particle diameter D50.

[0172] [Hydrophobic dispersion medium] Naphthenic hydrocarbons: Vapor pressure (25°C): 0.001 kPa, Flash point: 115°C (closed method), Total content of benzene-based organic solvents and halogen-based organic solvents: 0.5% by mass or less Isoparaffinic hydrocarbons: Vapor pressure (25°C): 0.006 kPa, Flash point: 86°C (closed method), Total content of benzene-based organic solvents and halogen-based organic solvents: 0.5% by mass or less [emulsifier] • POA1 • Polyoxyethylene decyl ether (HLB: 13.2) POA2 - Polyoxyalkylene alkyl ether (HLB: 13.3) [Polishing accelerator] The following polishing accelerators were used.

[0173] [Table 1]

[0174] (Preparation of the polishing composition of Example 1) A hydrophobic mixture was prepared by adding 2.5 parts by mass of POA1 (emulsifier) ​​to 20 parts by mass of naphthenic hydrocarbon (hydrophobic dispersion medium).

[0175] Next, water (the remaining amount of components other than water when the total composition is 100 parts by mass) was mixed with 1.3 parts by mass of a polyacrylic acid polymer (thickener), an alkali-soluble thickener, and 2.0 parts by mass of glycerin (emulsifying stabilizer). The resulting hydrophilic mixture was added to the hydrophobic mixture and stirred at 5,000 rpm for 10 minutes at room temperature (25°C) using a homomixer to perform emulsification and obtain an emulsion. Then, 10 parts by mass of abrasive grains and 0.09 parts by mass of tetraalkylammonium chloride (polishing accelerator), a quaternary ammonium salt, were added and stirred. A preservative was added to the resulting dispersion, and sodium hydroxide was added as an alkali to adjust the pH to 9.0, thus preparing the polishing composition of Example 1.

[0176] In the polishing composition obtained in Example 1, the average primary particle diameter of the abrasive grains was 0.18 μm, and the average secondary particle diameter D50 was 2.4 μm.

[0177] (Preparation of polishing compositions for Examples 2-18) Polishing compositions for Examples 2 to 18 were prepared in the same manner as in Example 1, except that the types and amounts of the hydrophobic dispersion medium, emulsifier, and polishing accelerator were changed to those listed in Tables 2 and 3.

[0178] In the polishing compositions obtained in Examples 2 to 18, the average primary particle size of the abrasive grains was 0.18 μm, and the average secondary particle size D50 was 2.4 μm.

[0179] (Preparation of polishing compositions for Comparative Examples 1-3) The polishing compositions of Comparative Examples 1 to 3 were prepared in the same manner as in Example 1, except that the hydrophobic dispersion medium and emulsifier were used in the types and amounts listed in Table 3, and no polishing accelerator was used.

[0180] In the obtained comparative examples 1 to 3 of abrasive compositions, the average primary particle diameter of the abrasive grains was 0.18 μm, and the average secondary particle diameter D50 was 2.4 μm.

[0181] <Evaluation of abrasive compositions> The obtained polishing compositions were subjected to viscosity measurement, processing force (polishing time) evaluation, and color evaluation according to the following procedure. The results of these evaluations are shown in Tables 2 and 3.

[0182] [Viscosity measurement] The viscosity of the polishing composition was measured at 25°C using a Type B viscometer (model number: TVB-10, rotor No. H5, rotor rotation speed: 20 rpm) manufactured by Toki Sangyo Co., Ltd.

[0183] [Evaluation of processing force (polishing time)] Polishing was performed using the polishing compositions of the examples and comparative examples under the following polishing conditions, and the processing force (polishing time) was evaluated according to the method described below. As mentioned above, the shorter the polishing time required to remove (eliminate) the scratches, the better the processing force.

[0184] (polishing conditions) The polishing machine used was a single-action polisher FLEX PE-14-2 (manufactured by FLEX), and the specific polishing conditions were as follows:

[0185] (Testing with wool buffs) Buff: Wool buff (hair length: approximately 10mm) Pressing force: 4kg Polisher rotation speed: 1200 rpm Flow rate of polishing composition: 0.4g / 20 seconds Polishing time: The time it took to visually confirm the removal of polishing marks (scratches) by dry sanding the clear coat with #1500 grit sandpaper. Polishing area: 600×400mm The material used for polishing was a composite material with a clear coating applied to the surface of a steel plate using synthetic resin paint, and the pencil hardness of the clear coating was F.

[0186] [Evaluation of color tone (color difference △E)] The state of the finished surface of the object to be polished can be evaluated by measuring the color difference ΔE. The smaller the color difference ΔE, that is, the closer it is to 0 (zero), the better the state of the finished surface can be said to be. Here, the color difference ΔE is a quantification of the color difference (the difference in roughness of the surface state) between the two measured coating film surfaces, and is calculated by the following formula (ii). Color difference ΔE = [(L2 - Ll) 2 +(a2 - al) 2 +(b2 - bl) 2 1 / 2 … Formula (ii) In formula (ii), L represents lightness, and a and b represent hue and chroma.

[0187] Using formula (ii), based on the coating film surface after painting (that is, the new painted surface), the color difference ΔE of the coating film surface after polishing is calculated. The closer the value of the color difference ΔE is to 0, the fewer or shallower the processing scratches are, and the coating film surface after painting and the coating film surface after polishing have the same appearance. On the other hand, when the value of the color difference ΔE is large, there are many or deep processing scratches, and there is a difference in the appearance between the coating film surface after painting and the coating film surface after polishing.

[0188] The evaluation device and measurement conditions of the color difference ΔE are as follows. · Evaluation device: Multi-angle type spectrocolorimeter CM-512m3A (manufactured by Konica Minolta Co., Ltd.) · Measurement conditions: Field of view 2° / Light source: Standard illuminant D65 (daylight, correlated color temperature 6504 K) / Light source 25°.

[0189] (Evaluation results) The evaluation results of the viscosity, processing force (polishing time), and color tone of the polishing compositions of Examples 1 to 18 and Comparative Examples 1 to 3 are shown in Tables 2 and 3.

[0190]

Table 2

[0191]

Table 3

[0192] As shown in Tables 2 and 3, when using the polishing compositions of Examples 1 to 18, the scratch removal time was shortened, and there were no problems in terms of scratches, etc., as measured by color difference, indicating that the polishing compositions of Examples 1 to 18 have good processing power in rough polishing.

[0193] This indicates that including polyoxyalkylene alkyl ether and a polishing accelerator in the polishing composition results in superior processing power.

Claims

1. It contains abrasive particles, an emulsifier, a polishing accelerator, a hydrophobic dispersion medium, and water. The emulsifier is a polyoxyalkylene alkyl ether. The polishing agent is a surfactant (however, it is a surfactant different from the emulsifier) ​​in the polishing composition.

2. The polishing composition according to claim 1, comprising adding the abrasive particles and the polishing accelerator to an emulsion in which micelles are formed with the hydrophobic dispersion medium, the emulsifier, and the water.

3. The polishing composition according to claim 1 or 2, wherein the polishing accelerator is contained in an amount of 0.01% by mass or more and 3.0% by mass or less based on the total mass of the composition.

4. The polishing composition according to claim 1 or 2, wherein the polishing accelerator comprises an ionic surfactant.

5. The polishing composition according to claim 1 or 2, wherein the polishing accelerator is a quaternary ammonium salt or an amine salt.

6. The polishing composition according to claim 1 or 2, wherein the polishing accelerator is one or more selected from the group consisting of carboxylates, sulfonates, sulfates, and phosphates.

7. The polishing composition according to claim 1 or 2, wherein the polishing accelerator is contained in an amount of 0.01% by mass or more and 0.6% by mass or less based on the total mass of the composition.

8. The polishing composition according to claim 1 or 2, wherein the mass ratio of the emulsifier to the polishing accelerator (mass content of emulsifier / mass content of polishing accelerator) is 2 or more and 35 or less.

9. The emulsifier is a polyoxyethylene alkyl ether having an alkyl group with 8 to 12 carbon atoms. The polishing composition according to claim 1 or 2, wherein the emulsifier is present in an amount of 2.0 mol% or more when the molar content of the hydrophobic dispersion medium is 100 mol%.

10. The abrasive composition according to claim 1 or 2, wherein the hydrophobic dispersion medium has a vapor pressure of 0.0001 kPa or more and 2 kPa or less at 20°C.

11. The hydrophobic dispersion medium comprises at least one selected from the group consisting of normal paraffinic hydrocarbons, isoparaffinic hydrocarbons, naphthenic hydrocarbons, and terpene hydrocarbons. The polishing composition according to claim 1 or 2, wherein the vapor pressure of the hydrophobic dispersion medium at 20°C is 0.0001 kPa or more and 2 kPa or less.

12. The abrasive composition according to claim 1 or 2, wherein the hydrophobic dispersion medium comprises at least two selected from the group consisting of normal paraffinic hydrocarbons, isoparaffinic hydrocarbons, naphthenic hydrocarbons, and terpene hydrocarbons.

13. The polishing composition according to claim 1 or 2, wherein the flash point of the hydrophobic dispersion medium is 50°C or higher and 120°C or lower.

14. The abrasive composition according to claim 1 or 2, wherein the hydrophobic dispersion medium is contained in an amount of 15% by mass or more and 40% by mass or less based on the total mass of the abrasive composition.

15. The polishing composition according to claim 1 or 2, wherein the abrasive grains are aluminum oxide.

16. The abrasive composition according to claim 1 or 2, wherein the abrasive grains are contained in an amount of 5% by mass or more and 45% by mass or less based on the total mass of the abrasive composition.

17. A process of mixing a hydrophobic dispersion medium, an emulsifier, and water to emulsify and obtain an emulsion; The process involves mixing an abrasive accelerator and abrasive particles into the aforementioned emulsion to obtain an abrasive composition; A method for producing an abrasive composition containing [the specified ingredient].

18. A polishing method for polishing an object to be polished using the polishing composition described in claim 1 or 2.

19. The polishing method according to claim 18, wherein the object to be polished includes at least one selected from the group consisting of resin material, alloy material, and glass material.

20. The polishing method according to claim 19, wherein the object to be polished is a painted surface, and the painted surface is polished with a wool buff and / or a sponge buff.

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