TWI758236B - Abrasive material, polishing composition and polishing method - Google Patents

Abstract

The present invention provides a grinding material, a grinding composition and a grinding method which can remove the undulations on the outer surface of the resin coating film by grinding, and are less likely to produce grinding scratches. The polishing composition contains abrasives composed of alumina particles having a specific surface area of 5 m ² /g or more and 50 m ² /g or less and an average secondary particle size of 0.05 μm or more and 4.8 μm or less. The polishing composition is used for polishing the outer surface of the resin coating film.

Description

Abrasive material, polishing composition and polishing method

The present invention relates to a polishing material, a polishing composition, a polishing method, a coated member, and a method for producing the same.

A buffing polishing process is known as a processing method for smoothing the outer surface (hereinafter also referred to as "resin-coated surface") of a resin coating film coated on a surface of an automobile body and the like to generate gloss. The polishing and polishing process is, for example, a method of polishing a surface by pressing a rotating polishing pad against the polishing object while interposing a polishing composition between a cloth polishing pad and the polishing object.

The polishing composition used for polishing and polishing contains abrasives (abrasive grains), and as the abrasives, particles of, for example, alumina are used (see, for example, Patent Documents 1 to 3).

However, buffing and polishing using a polishing composition containing a conventional polishing material may not completely remove the undulations of the resin-coated surface. Furthermore, by using the polishing composition containing conventional abrasives for polishing and polishing, there may be cases where polishing scratches are formed on the resin-coated surface to be polished. Therefore, there is a resin-coated surface that cannot be modified to have a beautiful luster. situation.

[Prior Art Literature] [Patent Literature]

[Patent Document 1] Japanese Patent Laid-Open No. 2008-255232

[Patent Document 2] Japanese Patent Laid-Open No. 2008-127456

[Patent Document 3] Japanese Patent Laid-Open No. 2007-277379

Therefore, the subject of the present invention is to solve the problems of the above-mentioned prior art, and to provide an abrasive material, a polishing composition, and a polishing material that can remove the undulations on the outer surface of the resin coating film by polishing and are less likely to produce polishing scratches. method.

In order to solve the above-mentioned problems, the abrasive material in one form of the present invention is used for polishing the outer surface of a resin coating film, and the gist is that the specific surface area is 5 m ² /g or more and 50 m ² /g or less, and the average secondary particle size is 0.05 μm or more. Made of alumina particles below 4.8μm.

In the above-mentioned abrasives in one form, the alpha rate of alumina is preferably 40% or more.

Furthermore, the requirements of the polishing composition of another aspect of the present invention Intended to contain the above-mentioned abrasive materials.

In the polishing composition of the above-mentioned other aspect, the content of the abrasive is preferably not less than 0.1% by mass and not more than 50% by mass.

Furthermore, the gist of the polishing method in another aspect of the present invention is to polish the outer surface of the resin coating film using the polishing composition in another aspect.

In the above-mentioned other aspect of the polishing method, the polishing is preferably performed while keeping the polishing temperature below the glass transition point of the resin constituting the resin coating film.

Further, in the above-mentioned polishing method of another aspect, it is preferable to perform polishing while keeping the polishing temperature at 50° C. or lower.

Furthermore, in the above-mentioned polishing method of another aspect, the polishing is preferably performed with a polishing pad having a soft polishing surface.

Furthermore, in the above-mentioned other aspect of the polishing method, it is preferable to use a second polishing pad having a harder polishing surface than the polishing surface of the polishing pad with soft polishing The polishing pad is subjected to the second stage of polishing.

In addition, in the above-mentioned polishing method according to another aspect, it is preferable to polish with a constant pressing force on the polishing surface of the outer surface of the resin coating film.

In addition, the coating member of another aspect of the present invention is a coating member obtained by coating the surface of the substrate with a resin coating film, and the gist is to polish the outer surface of the resin coating film using the polishing composition of the other aspect.

Furthermore, another aspect of the present invention is a method for producing a coated member in which the surface of a substrate is coated with a resin coating film, and the gist of the method is to grind using the polishing composition of the other aspect. Painting components The step of coating the outer surface of the resin film.

According to the polishing material, polishing composition and polishing method of the present invention, the undulations on the outer surface of the resin coating film can be removed by polishing, and polishing scratches are not easily generated.

1‧‧‧Automatic grinding device

2‧‧‧Robot arm

4‧‧‧Abrasive Tools

5‧‧‧Pressure pressure detector

7‧‧‧Control Department

10‧‧‧Polishing pads

10a‧‧‧Abrasive surface

20, 21, 22‧‧‧joint

23‧‧‧Front end

90‧‧‧Objects to be ground

FIG. 1 is a diagram showing the configuration of an automatic polishing apparatus used in one embodiment of the polishing method of the present invention.

Embodiments of the present invention will be described in detail. The abrasive material of this embodiment is suitable for grinding (eg, polishing) the outer surface (resin-coated surface) of the resin coating film, and has a specific surface area of 5 m ² /g to 50 m ² /g, and the average secondary particle It consists of alumina (Al ₂ O ₃ ) particles with a diameter of 0.05 μm or more and 4.8 μm or less. If the specific surface area is 5 m ² /g or more and 50 m ² /g or less, the undulations of the resin-coated surface can be removed by grinding using the abrasive material, and grinding flaws are not easily generated on the resin-coated surface. Therefore, it can be modified into a resin-coated surface with a beautiful luster. The specific surface area of alumina is preferably not less than 8 m ² /g and not more than 45 m ² /g, more preferably not less than 10 m ² /g and not more than 400 m ² /g. In addition, the specific surface area of alumina can be measured by, for example, the BET method.

In addition, if the average secondary particle size of the alumina particles is 0.05 μm More than 4.8 μm or less, the surface roughness of the resin-coated surface after grinding is excellent, and the resin-coated surface after grinding is less likely to produce grinding flaws such as scratches. The average secondary particle size of alumina is preferably 0.1 μm or more and 4.0 μm or less, more preferably 0.2 μm or more and 3.5 μm or less. In addition, the average secondary particle size of alumina particles is measured using, for example, a laser diffraction/scattering particle size distribution analyzer LA-950 manufactured by Horiba Manufacturing Co., Ltd.

The alpha rate of the alumina may also be 40% or more. When the α-forming rate is 40% or more, polishing can be performed at a high polishing rate. The alpha rate of alumina is more preferably 45% or more, and still more preferably 50% or more.

The production method of the alumina particles is not particularly limited, but the alumina having the above-mentioned physical properties can be produced by a method of obtaining aluminum hydroxide by the Bayer method (wet method), and then heat-treating it into alumina.

The abrasive can be used as abrasive grains of a polishing composition suitable for polishing (eg, buffing) of a resin-coated surface. That is, the polishing composition of the present embodiment contains the above-mentioned polishing material. When the resin-coated surface is polished with this polishing composition, the undulations of the resin-coated surface can be removed, and polishing scratches are less likely to be generated on the resin-coated surface. Therefore, it can be modified into a resin-coated surface with a beautiful luster.

The content of the abrasive may be 0.1 mass % or more and 50 mass % or less of the entire polishing composition. When the content of the abrasive is 0.1 mass % or more, the resin-coated surface can be polished at a high polishing rate. In addition, when the content of the abrasive is 50 mass % or less, the cost of the polishing composition can be suppressed, and the occurrence of scratches on the resin-coated surface after polishing can be further suppressed. The content of the abrasive is more preferably not less than 0.5% by mass and not more than 40% by mass, and More preferably, it is 1.0 mass % or more and 30 mass % or less.

Although the kind of the resin coating film is not particularly limited, the resin constituting the resin coating film includes, for example, urethane resin and acrylic resin. The resin coating film is preferably a transparent clear coating film. Moreover, the thickness of a resin coating film is not specifically limited, either, It may be 100 micrometers or less, and 10 micrometers or more and 40 micrometers or less may be sufficient as it.

The polishing composition of the present embodiment can be used for the manufacture of a coated member in which the surface of a base material is coated with a resin coating film. If the outer surface of the resin coating film of the coating member is polished using the polishing composition of the present embodiment, a coating member having a resin coating film with few undulations and polishing scratches and having a beautiful gloss can be produced.

The type of the coating member (that is, the use of the resin coating film) is not particularly limited, and examples thereof include automobile bodies, railway carriages, airplanes, and resin-made members. The resin coating film covering the surface of the automobile body has a large area and a curved surface, and the abrasive material and the polishing composition of this embodiment are suitable for the polishing system of the outer surface of the resin coating film.

Specific examples of the base material include iron alloys such as stainless steel, aluminum alloys, and resins. Ferroalloys are used as, for example, steel sheets for general cabins including automobiles. For example, stainless steel is used in railway carriages. The steel plate can also be surface-coated. In addition, aluminum alloys are used for parts of automobiles, airplanes, and the like. In addition, resin is used for the resin-made member, such as a bumper.

The polishing composition can be produced by mixing a polishing material with a liquid medium such as water and an organic solvent. The liquid medium serves as a component (alumina particles, additives, etc.) for polishing the composition. Dispersing or dissolving dispersion medium or solvent function. The liquid medium is exemplified by water and an organic solvent, and may be used alone or in combination of two or more, but preferably contains water. However, from the viewpoint of preventing the action of each component from being hindered, it is preferable to use water free from impurities as much as possible. Specifically, it is preferably pure water, ultrapure water, or distilled water in which foreign matter is removed by a filter after removing impurity ions by an ion exchange resin.

In addition, pH adjusters, surfactants, polishing accelerators, oxidizing agents, dispersing agents, viscosity adjusting agents, dissolving agents, anti-corrosion agents, anti-corrosion agents, and anti-corrosion agents may be added to the polishing composition of the present embodiment as necessary to improve its performance. Mildew and other additives. Hereinafter, the example of the additive which can be mix|blended with the polishing composition of this embodiment is demonstrated.

(1) pH adjuster

The pH of the polishing composition can be adjusted by adding a pH adjuster. The pH adjuster used as needed to adjust the pH value of the polishing composition to a desired value may be any one of an acid and a base, and may be any one of an inorganic compound and an organic compound.

Specific examples of the acid of the pH adjuster include inorganic acids, and organic acids such as carboxylic acids and organic sulfuric acid. Specific examples of the inorganic acid include sulfuric acid, nitric acid, boric acid, carbonic acid, hypophosphorous acid, phosphorous acid, phosphoric acid, and the like. In addition, specific examples of the carboxylic acid 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 - Methylvaleric acid, n-heptanoic acid, 2-methylhexanoic acid, n-octanoic acid, 2-ethylhexanoic acid, benzoic acid, glycolic acid, salicylic acid, glyceric acid, oxalic acid, malonic acid, succinic acid Acid, glutaric acid, adipic acid, pimelic acid, maleic acid, phthalic acid, malic acid, tartaric acid, citric acid, lactic acid, etc. In addition, specific examples of organic sulfuric acid include methanesulfonic acid, ethanesulfonic acid, isethionic acid, and the like. These acids may be used alone or in combination of two or more.

Specific examples of the base as the pH adjuster include alkali metal hydroxides or their salts, alkaline earth metal hydroxides or their salts, quaternary ammonium hydroxide or their salts, ammonia, amines, and the like.

Specific examples of the alkali metal include potassium, sodium, and the like. In addition, specific examples of alkaline earth metals include calcium, strontium, and the like. Further, specific examples of the salt include carbonates, bicarbonates, sulfates, acetates, and the like. In addition, specific examples of quaternary ammonium include tetramethylammonium, tetraethylammonium, tetrabutylammonium, and the like.

The quaternary ammonium hydroxide compound includes quaternary ammonium hydroxide or a salt thereof, and specific examples thereof include, for example, tetramethylammonium hydroxide, tetraethylammonium hydroxide, and tetrabutylammonium hydroxide.

In addition, specific examples of the amine include methylamine, dimethylamine, trimethylamine, ethylamine, diethylamine, triethylamine, ethylenediamine, monoethanolamine, N-(β-aminoethyl)ethanolamine, hexamethyleneamine Methyldiamine, Diethylenetriamine, Triethylenetetramine, Piperazine Anhydrous, Piperazine Hexahydrate, 1-(2-aminoethyl)piperazine, N-Methylpiperazine, Guanidine Wait.

These bases may be used alone or in combination of two or more.

Among these bases, ammonia, ammonium salts, alkali metal hydroxides, alkali metal salts, quaternary ammonium hydroxide compounds, and amines are preferred, and ammonia, potassium compounds, sodium hydroxide, and tetrahydroxide are more suitable. grade ammonium compounds, ammonium bicarbonate, Ammonium carbonate, sodium bicarbonate and sodium carbonate.

In addition, the polishing composition preferably contains a potassium compound as the base from the viewpoint of preventing metal contamination. The potassium compound is exemplified by potassium hydroxide or potassium salt, specifically potassium hydroxide, potassium carbonate, potassium hydrogencarbonate, potassium sulfate, potassium acetate, potassium chloride and the like.

Moreover, instead of the aforementioned acid or in combination with the aforementioned acid, a salt such as an ammonium salt or an alkali metal salt of the aforementioned acid may be used as a pH adjuster serving as a buffer. In particular, when the combination of the aforementioned acid and buffer is a combination of a weak acid and a strong base, a strong acid and a weak base, or a weak acid and a weak base, a pH buffering effect can be expected.

(2) Surfactant

A surfactant may be added to the polishing composition. Since the surfactant has the function of imparting hydrophilicity to the polished surface of the polished resin-coated surface, the cleaning efficiency of the polished resin-coated surface can be improved, and the adhesion of dirt and the like can be suppressed. The surfactant may be any one of anionic surfactants, cationic surfactants, amphoteric surfactants and nonionic surfactants.

Specific examples of the anionic surfactant include polyoxyethylene alkyl ether acetic acid, polyoxyethylene alkyl sulfate, alkyl sulfate, polyoxyethylene alkyl sulfate, alkyl sulfate, alkyl sulfate Benzene Sulfonic Acid, Alkyl Phosphate, Polyoxyethylene Alkyl Phosphate, Polyoxyethylene Sulfosuccinic Acid, Alkyl Sulfosuccinic Acid, Alkyl Naphthalene Sulfonic Acid, Alkyl Diphenyl Ether Disulfonic Acid acid, or a salt thereof.

In addition, a specific example of the cationic surfactant includes an alkyl group Trimethylammonium salt, alkyldimethylammonium salt, alkylbenzyldimethylammonium salt, alkylamine salt, etc.

Further, specific examples of the amphoteric surfactant include alkylbetaines and alkylamine oxides.

Further, specific examples of the nonionic surfactant include polyoxyethylene alkyl ethers, polyoxyalkylene alkyl ethers, sorbitan fatty acid esters, glycerin fatty acid esters, and polyoxyethylene fatty acids. acid esters, polyoxyethylidene alkylamines, alkyl alkanolamides, etc.

These surfactants may be used alone or in combination of two or more.

(3) About polishing accelerators (oxidizing agents)

A polishing accelerator may also be added to the polishing composition. The polishing accelerator plays the role of chemical polishing of the polishing object, and can significantly improve the processing efficiency by acting on the outer surface of the resin coating film.

Specific examples of the polishing accelerator include at least one salt selected from the group consisting of metal salts of inorganic acids, metal salts of organic acids, ammonium salts of inorganic acids, and ammonium salts of organic acids.

The inorganic acid may be any of nitric acid, sulfuric acid and hydrochloric acid. The organic acid may be any one of oxalic acid, lactic acid, acetic acid, formic acid, citric acid, tartaric acid, malic acid, gluconic acid, glycolic acid, and malonic acid. The metal salt may be any one of aluminum salt, nickel salt, lithium salt, magnesium salt, sodium salt, and potassium salt.

These polishing accelerators may be used alone or in combination of two or more.

In addition, an oxidizing agent may be added as a polishing accelerator. Specific examples of the oxidizing agent include hydrogen peroxide, peroxide, nitrate, iodate, periodate, hypochlorite, chlorite, chlorate, perchlorate, persulfate, hydrogen peroxide Chromate, permanganate, ozone water, silver (II) salt, iron (III) salt, etc.

(4) About dispersants/viscosity modifiers (tackifiers)

A dispersant or a viscosity modifier (tackifier) may also be added to the polishing composition. The abrasive material is uniformly dispersed in the liquid by the effect of the dispersing agent or the tackifier, so that the abrasive material can effectively act on the object to be polished. Moreover, by making a dispersing agent or a tackifier exist between abrasives, the effect of suppressing the caking of abrasive grains can also be expected. Thereby, the occurrence of scratches due to the aggregated abrasive is suppressed.

A specific example of the dispersing agent is a colloidal substance containing a substance containing fine particles. Colloidal substances are exemplified by, for example, colloidal alumina, colloidal silica, colloidal zirconia, colloidal titania, alumina sol, silica sol, zirconia sol, titania sol, fumed alumina, fumed silica , fumed zirconia, fumed titanium oxide, etc. Sodium phosphate, sodium hexametaphosphate, sodium pyrophosphate, etc., which are generally used as dispersants, can also be used.

Specific examples of the tackifier include glycols such as propylene glycol polymers and ethylene glycol polymers, or polymer compounds. More specifically, the glycols include propylene glycol, ethylene glycol, dipropylene glycol, polypropylene glycol, diethylene glycol, polyethylene glycol, and the like. The polymer compound is exemplified by sodium polyacrylate, polyvinyl alcohol, hydroxyethyl cellulose, and the like.

(5) About chelating agent

A chemical (combination agent) having a chelating effect may be added to the polishing composition. Since the chelating agent locks the metal ions or the like from the polishing apparatus or the object to be polished, metal contamination of the polished surface due to metal ions is suppressed, and a favorable polished surface can be expected.

Examples of the chelating agent include organic acids, amino acids, nitrile compounds, and chelating agents other than these. Specific examples of the organic acid include, for example, oxalic acid, malonic acid, succinic acid, glutaric acid, adipic acid, pimelic acid, maleic acid, phthalic acid, malic acid, tartaric acid, citric acid, and the like. Instead of an organic acid or in combination with an organic acid, a salt such as an alkali metal salt of an organic acid may be used.

Specific examples of the amino acid include glycine, α-alanine, β-alanine, N-methylglycine, N,N-dimethylglycine, 2-aminobutyric acid, norvaline amino acid, valine, leucine, norleucine, isoleucine, phenylalanine, proline, sarcosine, ornithine, lysine, taurine, serine, Threonine, homoserine, tyrosine, N,N-dihydroxyethylglycine (bicine), N-parahydroxymethylglycine (tricin), 3,5-diiodotyramine Acid, β-(3,4-dihydroxyphenyl)-alanine, thyroxin, 4-hydroxy-proline, cysteine, methionine, ethionine, lanthiamine Lanthionine, cystathionine, cystine, cysteic acid, aspartic acid, glutamic acid, S-(carboxymethyl)-cysteine, 4-amine Butyric acid, asparagine, glutamine, azaserine, arginine, canavanine, citrulline acid, delta-hydroxylysine, creatine, histidine, 1-methylhistidine, 3-methylhistidine, tryptophan, etc.

Specific examples of the nitrile compound include, for example, acetonitrile, aminoacetonitrile, propionitrile, butyronitrile, isobutyronitrile, benzonitrile, glutaronitrile, methoxyacetonitrile, and the like.

Specific examples of chelating agents other than these include iminodiacetic acid, nitrotriacetic acid, diethylenetriaminepentaacetic acid, ethylenediaminetetraacetic acid, N,N,N-trimethylenephosphonic acid, ethyl acetate Diamine-N,N,N',N'-tetramethylenesulfonic acid, trans-cyclohexanediaminetetraacetic acid, 1,2-diaminopropanetetraacetic acid, glycol ether diaminetetraacetic acid, ethyl acetate Diamine o-hydroxyphenylacetic acid, ethylenediamine disuccinic acid (SS form), N-(2-carboxylate ethyl)-L-aspartic acid, β-alanine diacetic acid, 2-phosphonobutane -1,2,4-Tricarboxylic acid, 1-Hydroxyethylene-1,1-diphosphonic acid, N,N'-bis(2-hydroxybenzyl)ethylenediamine-N,N'-diacetic acid , 1,2-dihydroxybenzene-4,6-disulfonic acid, etc.

These dissolving agents may be used alone or in combination of two or more.

(6) About anti-corrosion agent

A corrosion inhibitor may be added to the polishing composition. Since the corrosion inhibitor forms a protective film on the metal surface, it can be expected to prevent corrosion of polishing equipment, polishing objects, fixtures, and the like.

The anticorrosion agent that can be used is not particularly limited, such as a heterocyclic compound or a surfactant. The number of members of the heterocycle in the heterocyclic compound is not particularly limited.

In addition, the heterocyclic compound may be a monocyclic compound or a polycyclic compound having a condensed ring. The anticorrosion agent may be used alone or in combination of two or more.

Specific examples of the heterocyclic compound that can be used as an anticorrosion agent include, for example, pyrrole compounds, pyrazole compounds, imidazole compounds, triazole compounds, tetrazole compounds, pyridine compounds, piperidine compounds, pyrazine compounds, pyrazine compounds, indole compounds Indolizine compounds, indole compounds, isoindole compounds, indazole compounds, purine compounds, quinolizine compounds, quinoline compounds, isoquinoline compounds, naphthyridine compounds, phthalazine compounds, quinoxaline compounds , quinazoline compounds, cinnoline compounds, pteridine compounds, thiazole compounds, isothiazole compounds, oxazole compounds, isoxazole compounds, furzan compounds and other nitrogen-containing heterocyclic compounds.

(7) About antifungal agents and preservatives

Antifungal agents and preservatives may be added to the polishing composition. Specific examples of antifungal agents and antiseptics include isothiazoline-based antiseptics (for example, 2-methyl-4-isothiazolin-3-one, 5-chloro-2-methyl-4-isothiazoline-3 - ketones), parabens, phenoxyethanol. These antifungal agents and preservatives may be used alone or in combination of two or more.

The polishing composition of the present embodiment can be used for polishing a resin-coated surface. Here, an example of the grinding|polishing method of the resin-coated surface is demonstrated. The structure of the grinding apparatus for grinding is not particularly limited, and a general grinding apparatus can be used, for example, the automatic grinding apparatus 1 in FIG. 1 can be used.

The automatic polishing apparatus 1 of FIG. 1 includes a robot arm 2 , a polishing pad 10 , a polishing tool 4 , a pressing force detection unit 5 , and a controller 7 . Since the robot arm 2 has a plurality of joints 20 , 21 , and 22 , the polishing pad 10 , the polishing tool 4 , and the front end portion 23 to which the pressing force detection portion 5 is attached can be moved in plural directions. The object to be polished 90 (corresponding to the "coated member" of the constituent elements of the present invention) is preferably, for example, a vehicle body such as an automobile whose surface is coated with a resin coating film. The resin-coated surface of the body of an automobile or the like has a large area and a curved surface.

The polishing tool 4 is mounted on the front end portion 23 through the pressing force detecting portion 5 , and the polishing pad 10 is rotated by a direction perpendicular to the polishing surface 10 a of the polishing pad 10 as a rotation axis by a built-in driving means. The controller 7 controls the movement of the robot arm 2 and the rotation of the polishing pad 10 by the polishing tool 4 . The polishing composition is supplied between the polishing surface 10 a of the polishing pad 10 and the resin-coated surface of the polishing object 90 from a polishing composition supply mechanism (not shown).

The controller 7 polishes the resin-coated surface of the polishing object 90 by pressing the polishing surface 10 a of the polishing pad 10 against the resin-coated surface of the polishing object 90 with the robot arm 2 and rotating the polishing pad 10 . The pressing force detection unit 5 detects the pressing force of the polishing surface 10 a of the polishing pad 10 with respect to the resin-coated surface of the polishing object 90 . The controller 7 adjusts the force with which the polishing surface 10 a is pressed against the resin-coated surface of the polishing object 90 based on the detection result of the pressing force by the pressing force detecting unit 5 . Then, the controller 7 keeps the pressing force of the polishing surface 10a on the resin-coated surface of the object to be polished 90 constant based on the detection result of the pressing force by the pressing force detection unit 5 so that the polishing pad 10 is pressed against the resin of the object to be polished 90 . The way the painted surface moves, controls Robotic arm 2.

However, the polishing method of the present embodiment is not limited to the above-mentioned automatic polishing apparatus 1 . For example, the polishing method of this embodiment is also applicable to a case where a polishing pad is attached to the front end of a hand-held polisher, and a polishing operator moves the hand-held polisher by hand to polish a resin-coated surface.

When polishing the resin-coated surface, it is preferable to perform polishing while keeping the polishing temperature below the glass transition point of the resin constituting the resin coating film. Resin coatings (especially self-healing coatings) are weak to temperature changes, making it difficult to polish well. However, if the polishing temperature is kept below the glass transition point of the resin constituting the resin coating, it is easy to polish well. of grinding. That is, it is easier to remove the undulations of the resin-coated surface, and it is less likely that the resin-coated surface is scratched by grinding. Therefore, it becomes easier to modify the resin-coated surface with a beautiful gloss. Specifically, it is preferable to perform polishing while keeping the polishing temperature at 50°C or lower (more preferably 30°C or lower).

The method of measuring the polishing temperature is not particularly limited. For example, the polishing temperature can be obtained by measuring the temperature of the polishing surface 10a of the polishing pad 10 using, for example, an infrared radiation thermometer at the end of polishing.

In addition, the material of the polishing pad 10 is not particularly limited, and general non-woven fabrics, wool felts, polyurethane foams, polyethylene foams, porous fluororesins, and the like can be used without particular limitations. The polishing pad 10 can be used for providing grooves on the polishing surface 10a for storing the liquid polishing composition.

In addition, when polishing the resin-coated surface, it is preferable to polish with a polishing pad having a soft polishing surface. The hardness of the soft abrasive surface is preferably less than 50, more preferably 40 or less, according to the A hardness of JIS K 6253. Also, soft research The hardness of the grinding surface is preferably 30 or more in terms of A hardness. Within this range, the surface roughness of the resin-coated surface can be made more favorable.

The material of the polishing pad having a soft polishing surface is not particularly limited, as long as it is a material having the above-mentioned hardness, for example, non-woven fabric or wool felt.

Alternatively, when the resin-coated surface is polished, the second polishing pad with a hard polishing surface that is harder than the polishing surface of the first polishing pad with a soft polishing surface can be subjected to the first-stage polishing, and the second polishing pad with a soft polishing surface can be used for the first-stage polishing. A polishing pad is used for the second stage of polishing.

The hardness of the soft polishing surface of the first polishing pad is preferably, for example, less than 50, more preferably 40 or less, in terms of A hardness in accordance with JIS K 6253. Moreover, it is preferable that the hardness of the soft polishing surface which the 1st polishing pad has is A hardness, for example, 30 or more. Within this range, the surface roughness of the resin-coated surface is more favorable.

Furthermore, the hardness of the hard polishing surface of the second polishing pad is higher than the hardness of the soft polishing surface of the first polishing pad, according to A hardness of JIS K 6253, preferably 50 or more, more preferably 60 above. Moreover, the hardness of the hard grinding|polishing surface which a 2nd polishing pad has is A hardness, for example, Preferably it is 95 or less, More preferably, it is 80 or less. Within this range, it is easier to remove the undulations on the resin-coated surface.

The material of the first polishing pad is not particularly limited, as long as it is a material having the above-mentioned hardness, for example, non-woven fabric or wool felt. In addition, the material of the second polishing pad is not particularly limited, as long as it has the above-mentioned hardness, for example, polyurethane foam or non-woven cloth.

In addition, when grinding|polishing a resin-coated surface, it is preferable to grind|polish with the pressing force of the grinding|polishing surface 10a of the polishing pad 10 with respect to the resin-coated surface always being constant. Thereby, the whole resin-coated surface can be grind|polished uniformly.

In addition, the method of supplying the polishing composition between the polishing surface 10a of the polishing pad 10 and the resin-coated surface of the polishing object 90 is not particularly limited, and a continuous supply method such as a pump can be used. The supply amount of the polishing composition is not limited, but the polishing surface 10a of the polishing pad 10 is preferably always covered with the polishing composition. In addition, the polishing of the resin-coated surface of the object to be polished 90 may be performed directly using the stock solution of the polishing composition of the present embodiment, but a polishing agent obtained by diluting the stock solution with a diluent such as water by 2 times or more may also be used. A dilution of the composition is ground.

[Example]

The following examples and comparative examples are given to illustrate the present invention in more detail. 10 mass % of abrasives and 90 mass % of water were mixed to prepare the polishing compositions of Examples 1 to 8 and Comparative Examples 1 to 5, and the resin-coated surfaces were polished using these polishing compositions. All abrasives are alumina particles, and their average secondary particle size, specific surface area and alpha rate are shown in Table 1.

In addition, the average secondary particle size in Table 1 was measured using the laser diffraction/scattering particle size distribution analyzer LA-950 manufactured by Horiba Corporation. In addition, the specific surface area was measured using Flow SorbII 2300 manufactured by Micro Meritics. In addition, the alpha conversion rate is calculated|required from the integral intensity ratio of the (113) plane diffraction measured by X-ray diffraction.

The object to be polished is a metal plate whose surface is coated with a resin coating film (film thickness: 20 μm) made of a urethane resin with a clear coating. In addition, the polishing device used was AL-2 manufactured by Udagawa Iron & Steel Co., Ltd., the polishing pad used was polishing pad SURFIN 001-02 manufactured by Fujimi Incorporated Co., Ltd., and the hardness of the polishing surface was 44 in A hardness. Other grinding conditions are as follows. In addition, the polishing temperature is the temperature of the polishing surface of the polishing pad at the end of polishing measured using an infrared radiation thermometer.

Grinding pressure: 11.3kPa

Rotation speed of grinding platen: 130min ^-1

Supply amount of grinding composition: 5mL/min

Grinding time: 5 minutes

Grinding temperature: 23℃

After the polishing of the resin-coated surface of the object to be polished was completed, the polishing speed, the surface roughness Ra of the resin-coated surface, and the number of scratches generated on the resin-coated surface were evaluated. The results are shown in Table 1.

In addition, the polishing rate was calculated from the change in the mass of the object to be polished before and after polishing. In Table 1, when the polishing rate is 1.3 μm/min or more, it is represented by ⊚, when it is 0.3 μm/min or more and less than 1.3 μm/min, it is represented by ○, and when it is less than 0.3 μm/min, it is represented by ×.

In addition, in Table 1, when the surface roughness Ra of the resin-coated surface is 90 nm or less, it is represented by ⊚, when it exceeds 90 nm and less than 150 nm, it is represented by ○, and when it is 150 nm or more, it is represented by ×. The surface roughness Ra of the resin-coated surface was measured using a shape analysis laser microscope VK-X200 manufactured by KYENCE Co., Ltd.

In addition, in Table 1, when the number of scratches is 10 or less per 100 cm ² , it is indicated by ⊚, when the number of scratches is 11 or more and 50 or less, it is indicated by ○, and when 51 or more is indicated by ×. In addition, the scratches are linear grinding scratches, which are measured by visual observation under white light irradiation (illuminance 100001x) with a halogen lamp.

Claims (9)

A grinding method, which uses a grinding composition containing grinding materials to grind the outer surface of a resin coating film, the grinding material is used for grinding the outer surface of the urethane resin and/or acrylic resin coating film, and is determined by the specific surface area. It is composed of alumina particles having an average secondary particle size of 5 m ² /g or more and 50 m ² /g or less, and an average secondary particle size of 0.05 μm or more and 4.8 μm or less, and the alpha rate of the alumina is 40% or more. The grinding method of claim 1, wherein the content of the above-mentioned grinding material is 0.1 mass % or more and 50 mass % or less. The polishing method according to claim 1 or 2, wherein the polishing is performed while keeping the polishing temperature below the glass transition point of the resin constituting the resin coating film. The polishing method according to claim 1 or 2, wherein the polishing is performed while keeping the polishing temperature at 50°C or lower. According to the polishing method of claim 1 or 2, the polishing is performed with a polishing pad having a soft polishing surface. The polishing method of claim 5, wherein after the first-stage polishing is performed with a second polishing pad having a harder polishing surface than the polishing surface of the aforementioned polishing pad having a soft polishing surface, the aforementioned polishing pad having a soft polishing surface The polishing pad is subjected to the second stage of polishing. The grinding|polishing method of Claim 5 which grind|polishes with the pressing force with respect to the said grinding|polishing surface of the said resin coating film outer surface constant. A coating member, which is a coating member formed by coating the surface of a substrate with a resin coating film, and before being ground by the grinding method as claimed in claim 1 or 2 The outer surface of the resin coating film. A method of manufacturing a coated member, which is a method of manufacturing a coated member obtained by coating the surface of a base material with a resin coating film, and has the resin coating for grinding the aforementioned coated member by the grinding method as claimed in claim 1 or 2. step on the outer surface of the membrane.

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