JP2023132658A - Sand blast treatment method - Google Patents

Abstract

To provide a sand blast treatment method which can remove a photosensitive resin layer after sand blast treatment from a carbon fiber-reinforced plastic without residues.SOLUTION: A sand blast treatment method includes: stacking a photosensitive resin layer which contains (A) an alkali-soluble cellulose derivative, (B) a photopolymerization initiator and (C) an urethane (meth)acrylate compound, and does not substantially contain (D) a carboxy group-containing acrylic resin, on a treated body made of a carbon fiber-reinforced plastic; imagewise exposing the photosensitive resin layer with light; removing a non-exposure part with an alkali developer and thereby forming a resist pattern on the treated body; and then subjecting the treated body to sand blast treatment through the resist pattern.SELECTED DRAWING: None

Description

The present invention relates to a sandblasting method.

BACKGROUND ART Carbon fiber reinforced plastics have been known as materials having high specific rigidity, low density, and low coefficient of thermal expansion. Carbon fiber reinforced plastic is a composite material that improves strength by putting carbon fibers in resin (polyester resin, vinyl ester resin, epoxy resin, phenolic resin, and thermoplastic resin), and is used in daily necessities, sporting goods, automobiles, and other materials. It is used in a wide range of fields, including the aerospace industry.

Conventionally, laser processing, cutting using a tool such as a drill, and sandblasting have been used as methods for microfabrication of carbon fiber reinforced plastics. Sandblasting is a process in which a resist pattern is provided as a mask material on the object to be processed, and then an abrasive is sprayed to selectively cut the non-mask areas. Processing by sandblasting is advantageous from the viewpoint of productivity. Patent Document 1 describes a method of drilling a workpiece made of carbon fiber reinforced plastic using a resist layer having sandblasting resistance. Further, Patent Document 2 describes a processing method that suppresses fluffing and peeling of a processed object made of carbon fiber reinforced plastic in a sandblasting process by adjusting the opening diameter of a resist layer having sandblasting resistance.

The photosensitive resin layer used as a mask material for this sandblasting process generally contains an alkali-soluble resin, urethane (meth)acrylate, and a photopolymerization initiator. Cellulose derivatives or carboxyl group-containing acrylic resins are known as alkali-soluble resins (see, for example, Patent Document 3).

In processing by sandblasting, it is necessary to remove the resist pattern from the object to be processed after sandblasting. As described in Patent Document 4, a method is known in which an aqueous solution of a basic compound such as an alkali metal hydroxide such as sodium hydroxide, N-methyldiethanolamine, pyridine, or piperidine is used as a stripping solution. .

On the other hand, the adhesiveness of the photosensitive resin layer used as a mask material is high, and the surface layer of the resist pattern is coated with fine abrasive after sandblasting, making it difficult for the stripping solution to penetrate into the photosensitive resin layer. be. In that case, a method of directly removing the resist pattern using hands or adhesive tape, or a method of burning off the resist pattern at high temperature can also be used (see Patent Document 5).

However, carbon fiber-reinforced plastics have a high adhesive strength with the photosensitive resin layer after curing, and even when removed using a stripping solution, resist pattern residues may remain on the object to be processed. Furthermore, even when the resist pattern is directly removed by hand, the resist pattern may break before it is peeled off from the object, making it difficult to peel it off. In addition, a method of burning away that involves high heat is undesirable because the resin constituting the carbon fiber reinforced plastic may deteriorate. For this reason, there has been a need for a method for sandblasting carbon fiber reinforced plastics that can remove the resist pattern from a carbon fiber reinforced plastic object without leaving any residue after sandblasting.

Japanese Patent Application Publication No. 2012-196751 International Publication No. 2018-062101 Japanese Patent Application Publication No. 2012-27357 Japanese Patent Application Publication No. 2006-78868 International Publication No. 2007-091476

An object of the present invention is to provide a sandblasting method capable of removing a resist pattern after sandblasting from carbon fiber reinforced plastic without leaving any residue.

As a result of intensive studies, the present inventors have found that the above problems can be solved by the invention described below.
(A) an alkali-soluble cellulose derivative, (B) a photopolymerization initiator, and (C) a urethane (meth)acrylate compound, and (D) a carboxy group-containing acrylic resin on an object made of carbon fiber reinforced plastic. A resist pattern is formed on the object to be processed by laminating a substantially free photosensitive resin layer, imagewise exposing the photosensitive resin layer, and removing the non-exposed areas with an alkaline developer. After forming the resist pattern, the object to be processed is subjected to sandblasting through the resist pattern.

According to the present invention, it is possible to provide a sandblasting method capable of removing a resist pattern after sandblasting from carbon fiber reinforced plastic without leaving any residue.

Hereinafter, the sandblasting method of the present invention will be explained in detail.

In the present invention, the photosensitive resin layer laminated on the object to be processed made of carbon fiber reinforced plastic contains (A) an alkali-soluble cellulose derivative as an alkali-soluble resin. Examples of the alkali-soluble cellulose derivative (A) include cellulose acetate phthalate, hydroxypropylmethylcellulose phthalate, hydroxypropylmethylcellulose acetate phthalate, and hydroxypropylmethylcellulose acetate succinate.

The acid value of the alkali-soluble cellulose derivative (A) is preferably 30 to 500 mgKOH/g, more preferably 100 to 300 mgKOH/g. If this acid value is less than 30 mgKOH/g, the time for alkaline development tends to be longer, while if it exceeds 500 mgKOH/g, blast resistance may decrease.

Furthermore, the weight average molecular weight of the alkali-soluble cellulose derivative (A) is preferably from 10,000 to 200,000, more preferably from 10,000 to 150,000. If the mass average molecular weight is less than 10,000, it may be difficult to form the photosensitive resin composition used in the present invention into a film, whereas if it exceeds 200,000, the solubility in an alkaline developer may decrease. tends to get worse.

The photosensitive resin layer in the present invention contains (B) a photopolymerization initiator. (B) As the photopolymerization initiator, 2-benzyl-2-dimethylamino-1-(4-morpholinophenyl)butan-1-one, 2-methyl-1-[4-(methylthio)phenyl]-2- Aromatic ketones such as morpholinopropan-1-one; 2-ethylanthraquinone, phenanthrenequinone, 2-tert-butylanthraquinone, octamethylanthraquinone, 1,2-benzanthraquinone, 2,3-benzanthraquinone, 2-phenylanthraquinone , 2,3-diphenylanthraquinone, 1-chloroanthraquinone, 2-methylanthraquinone, 1,4-naphthoquinone, 9,10-phenanthraquinone, 2-methyl-1,4-naphthoquinone, 2,3-dimethylanthraquinone, etc. quinones; benzoin ether compounds such as benzoin methyl ether, benzoin ethyl ether, and benzoin phenyl ether; benzoin compounds such as benzoin, methylbenzoin, and ethylbenzoin; benzyl dimethyl ketal, 1-hydroxycyclohexylphenyl ketone, 2-hydroxy-2- Methyl-1-phenylpropan-1-one, 1-[4-(2-hydroxyethoxy)phenyl]-2-hydroxy-2-methylpropan-1-one, 2-hydroxy-1-{4-[4- (2-hydroxy-2-methyl-propionyl)benzyl]phenyl}-2-methylpropan-1-one, 2-(dimethylamino)-2-[(4-methylphenyl)methyl]-1-[4-( Alkylphenones such as 4-morpholinyl)phenyl]-1-butanone; acylphosphine oxides such as 2,4,6-trimethylbenzoyldiphenylphosphine oxide and bis(2,4,6-trimethylbenzoyl)phenylphosphine oxide Class; 1,2-octanedione, 1-[4-(phenylthio)phenyl-, 2-(o-benzoyloxime)], ethanone, 1-[9-ethyl-6-(2-methylbenzoyl)-9H- 2-(o-chlorophenyl)-4,5-diphenylimidazole dimer, 2-(o-chlorophenyl)-4, 5-bis(methoxyphenyl)imidazole dimer, 2-(o-fluorophenyl)-4,5-diphenylimidazole dimer, 2-(o-methoxyphenyl)-4,5-diphenylimidazole dimer, 2,4,5-triarylimidazole dimers such as 2-(p-methoxyphenyl)-4,5-diphenylimidazole dimer; 9-phenylacridine, 1,7-bis(9,9'-acridinyl) ) Acridine derivatives such as heptane; N-phenylglycine, N-phenylglycine derivatives; Coumarin compounds; benzophenone, benzoylbenzoic acid, methyl benzoylbenzoate, 4-phenylbenzophenone, hydroxybenzophenone, acrylated benzophenone, 4-benzoyl-4 '-Methyldiphenyl sulfide, 3,3',4,4'-tetra(t-butylperoxycarbonyl)benzophenone, 4,4'-bis(dimethylamino)benzophenone, 4,4'-bis(diethylamino)benzophenone, etc. Examples include benzophenone compounds. The substituents on the aryl groups of the two 2,4,5-triarylimidazoles in the above 2,4,5-triarylimidazole dimer may be the same and give a symmetrical compound, or they may be different. Asymmetric compounds may also be provided. Furthermore, a thioxanthone compound and a tertiary amine compound may be combined, such as a combination of diethylthioxanthone and dimethylaminobenzoic acid. These may be used alone or in combination of two or more.

The photosensitive resin layer in the present invention contains (C) a urethane (meth)acrylate compound. (C) Urethane (meth)acrylate compound is a reaction product of a compound having a terminal isocyanate group and a (meth)acrylate compound having a hydroxy group, which is the reaction between a compound having a polyvalent hydroxy group and a polyvalent isocyanate compound. means. Examples of the compound having a polyvalent hydroxyl group include polyesters and polyethers having a hydroxyl group at the end; examples of the polyester include polyesters obtained by ring-opening polymerization of lactones, polycarbonates, ethylene glycol, Examples include polyesters obtained by condensation reactions of alkylene glycols such as propylene glycol, diethylene glycol, triethylene glycol, and dipropylene glycol with dicarboxylic acids such as maleic acid, fumaric acid, glutaric acid, and adipic acid. Specifically, the lactones include δ-valerolactone, ε-caprolactone, β-propiolactone, α-methyl-β-propiolactone, β-methyl-β-propiolactone, α,α-dimethyl -β-propiolactone, β,β-dimethyl-β-propiolactone, and the like. Specific examples of the polycarbonates include reaction products of diols such as bisphenol A, hydroquinone, and dihydroxycyclohexanone and carbonyl compounds such as diphenyl carbonate, phosgene, and succinic anhydride. Further, specific examples of the polyethers include polyethylene glycol, polypropylene glycol, polytetramethylene glycol, polypentamethylene glycol, and the like.

Specific examples of the polyvalent isocyanate compound that reacts with the compound having a polyvalent hydroxy group include dimethylene diisocyanate, trimethylene diisocyanate, tetramethylene diisocyanate, pentamethylene diisocyanate, hexamethylene diisocyanate, heptamethylene diisocyanate, 2,2- Dimethylpentane-1,5-diisocyanate, octamethylene diisocyanate, 2,5-dimethylhexane-1,6-diisocyanate, 2,2,4-trimethylpentane-1,5-diisocyanate, nonamethylene diisocyanate, 2,2,4 - Aliphatic or alicyclic diisocyanate compounds such as trimethylhexane diisocyanate, decamethylene diisocyanate, and isophorone diisocyanate can be mentioned, and these compounds can be used alone or in a mixture of two or more types.

Further, as (meth)acrylate compounds having a hydroxy group, specifically, 2-hydroxyethyl acrylate, 2-hydroxyethyl methacrylate, 3-hydroxypropyl acrylate, 3-hydroxypropyl methacrylate, and ε- Compounds containing 1 to 10 mol of caprolactone can be mentioned, and these compounds can be used alone or in combination of two or more.

Component (C) may contain a carboxy group. Containing a carboxyl group tends to improve solubility in an alkaline developer. Component (C) containing a carboxyl group is obtained by first reacting a diisocyanate compound and a diol compound having a carboxyl group so that isocyanate groups remain at both ends, and then adding a hydroxy group to the terminal isocyanate group of the reaction product. It can be obtained by reacting (meth)acrylate compounds that have.

The weight average molecular weight of component (C) is preferably 1,000 to 40,000.

The photosensitive resin layer in the present invention does not substantially contain (D) a carboxy group-containing acrylic resin as an alkali-soluble resin. (D) As the carboxyl group-containing acrylic resin, (meth)acrylates such as methyl (meth)acrylate and ethyl (meth)acrylate are copolymerized with ethylenically unsaturated carboxylic acids such as acrylic acid, methacrylic acid, and crotonic acid. Examples include acrylic polymers. It also contains dicarboxylic acids such as maleic acid, fumaric acid, and itaconic acid, their anhydrides and half esters, and other copolymerizable ethylenically unsaturated groups such as styrene, (meth)acrylonitrile, and (meth)acrylamide. Also included are polymers obtained by copolymerizing monomers. Note that "substantially" as used herein means that the amount of the carboxy group-containing acrylic resin is less than 5% by mass based on the total mass of the photosensitive resin layer, preferably 2% by mass or less, and more preferably 0% by mass. Mass%. This makes it possible to adjust the adhesion between the resist pattern and the carbon fiber reinforced plastic, and to remove the resist pattern after sandblasting from the carbon fiber reinforced plastic without any residue. If the content of the carboxy group-containing acrylic resin is 5% by mass or more based on the total mass of the photosensitive resin layer, phase separation will occur in the coating solution of the photosensitive resin composition used for producing the dry film resist described below. In addition, defects in the shape of the resist pattern and defects in peeling occur.

The photosensitive resin layer may contain components other than the above components (A) to (C), if necessary. Such components include photopolymerizable monomers, solvents, thermal polymerization inhibitors, plasticizers, colorants (dyes, pigments), photocoloring agents, photoreducing agents, thermal coloration inhibitors, fillers, and antifoaming agents. agents, flame retardants, adhesion-imparting agents, leveling agents, peel accelerators, antioxidants, fragrances, thermosetting agents, water repellents, oil repellents, etc., each of which is the sum of the above components (A) to (C). It can be contained in an amount of about 0.01 to 20% by mass based on the amount. These components can be used alone or in combination of two or more.

The photopolymerizable monomer is a compound having at least one polymerizable ethylenically unsaturated group in the molecule, other than component (C) urethane (meth)acrylate. For example, a compound obtained by reacting a polyhydric alcohol with an α,β-unsaturated carboxylic acid; a bisphenol A-based (meth)acrylate compound; a compound obtained by reacting a glycidyl group-containing compound with an α,β-unsaturated carboxylic acid. Compound; Nonylphenoxypolyethyleneoxyacrylate; γ-chloro-β-hydroxypropyl-β'-(meth)acryloyloxyethyl-o-phthalate, β-hydroxyalkyl-β'-(meth)acryloyloxyalkyl-o-phthalate, etc. Examples include phthalic acid compounds; (meth)acrylic acid alkyl esters, EO-modified and/or PO-modified nonylphenyl (meth)acrylates, and the like. Here, EO and PO represent ethylene oxide and propylene oxide, and are nonylphenyl (meth)acrylates having an ethylene oxide block structure and/or a propylene oxide block structure. These photopolymerizable monomers can be used alone or in combination of two or more types.

Further, as the photopolymerizable monomer, a compound having three or more polymerizable ethylenically unsaturated groups in the molecule may be used. Examples of photopolymerizable compounds having three or more polymerizable ethylenically unsaturated groups in the molecule include trimethylolpropane tri(meth)acrylate, ditrimethylolpropane tetra(meth)acrylate, and pentaerythritol tri(meth)acrylate. acrylate, pentaerythritol tetra(meth)acrylate, dipentaerythritol penta(meth)acrylate, dipentaerythritol hexa(meth)acrylate, trimethylolpropane triglycidyl ether tri(meth)acrylate, etc., and these may be used alone or Two or more types can be used.

In the photosensitive resin layer of the present invention, the content of (A) is preferably 20 to 50% by mass, and 25 to 35% by mass based on the total amount of (A), (B), and (C). It is more preferable that If the content of (A) is less than 20% by mass, film properties may deteriorate or developability may deteriorate. If the content of (A) exceeds 50% by mass, the resolution of the resist pattern may decrease.

The content of (B) is preferably 0.1 to 10% by mass, more preferably 0.2 to 5% by mass based on the total amount of (A), (B), and (C). preferable. If the content of (B) is less than 0.1% by mass, photopolymerizability may become insufficient. On the other hand, if it exceeds 10% by mass, absorption may increase on the surface of the photosensitive resin layer during exposure, resulting in insufficient photocrosslinking within the photosensitive resin layer.

The content of (C) is preferably 40 to 75% by mass, more preferably 55 to 70% by mass, based on the total amount of (A), (B), and (C). If the content of (C) is less than 40% by mass, crosslinking properties may decrease and photosensitivity may become insufficient. On the other hand, if it exceeds 75% by mass, the tackiness of the film surface of the photosensitive resin layer may increase.

The photosensitive resin layer in the present invention is a layer containing a photosensitive resin composition containing the above-mentioned components (A) to (C) and other components. As a method for laminating the resin layer, it is also possible to directly apply the photosensitive resin composition onto the object to be treated and dry it to laminate the photosensitive resin layer, but from the viewpoint of obtaining a more uniform photosensitive resin layer, A dry film resist (DFR) in which a photosensitive resin layer is formed by coating and drying the photosensitive resin composition on a support (carrier film) is prepared, and the surface of the photosensitive resin layer of the DFR is coated. A method of laminating on a processing body is preferably used. Further, the DFR may have a cover film on the photosensitive resin layer.

As the support for supporting the photosensitive resin layer, a transparent film that transmits actinic rays is preferable. The thickness of the support is preferably 10 to 100 μm because the thinner it is, the less light is refracted, and the thicker it is, the better the coating stability is. Examples of such films include films of polyethylene terephthalate, polycarbonate, and the like.

The cover film only needs to be able to peel off the uncured photosensitive resin layer, and a resin film with high mold releasability is used. Examples include polyethylene film, polypropylene film, and polyethylene film coated with a release agent such as silicone.

The surface processing method for a workpiece made of carbon fiber-reinforced plastic according to the present embodiment includes a step of pasting the above-mentioned photosensitive resin layer on the workpiece using a laminator, A process of exposing the resin layer to light through a mask pattern to form cured parts at predetermined locations, a process of removing the uncured photosensitive resin layer with a developer to form a resist pattern, and a process of spraying an abrasive to form a resist pattern. A sandblasting process in which the part of the carbon fiber-reinforced plastic object where no pattern is formed is cut; and a peeling process in which the resist pattern is removed from the cut carbon fiber-reinforced plastic object after the sandblasting process. including.

In the step of laminating the photosensitive resin layer on the object to be processed, the photosensitive resin layer and the support are laminated on the object to be processed in this order from the side of the object to be processed.

Examples of the lamination method include a method of laminating the photosensitive resin layer by pressing it onto the object to be processed while heating it using a laminator or the like.

The heating temperature of the photosensitive resin layer during the above-mentioned lamination is preferably 70 to 130° C., and the compression pressure is preferably 0.1 to 1.0 MPa, but these conditions are not particularly limited. In addition, if the photosensitive resin layer is heated to 70 to 130°C as described above, it is not necessary to preheat the object to be processed, but in order to further improve the adhesion, preheating the object to be processed is necessary. You can also do

After forming the photosensitive resin layer on the object to be processed in this manner, the pasted photosensitive resin layer is exposed to light through a mask material to form photocured portions at predetermined locations. At this time, if the support present on the photosensitive resin layer is transparent, the active light can be irradiated as is, but if it is opaque, the active light can be applied to the photosensitive resin layer after removing the support. It is preferable to irradiate.

As a light source for exposure, a known light source that effectively emits ultraviolet rays can be used, such as a carbon arc lamp, a mercury vapor arc lamp, an ultra-high pressure mercury lamp, a high pressure mercury lamp, a xenon lamp, etc. The irradiation amount and irradiation time of ultraviolet rays can be appropriately set depending on the photosensitive resin layer. Examples of the exposure method include a contact exposure method in which the mask pattern is exposed to light by bringing it into close contact with the dry film, and a non-contact exposure method in which the mask pattern is exposed using parallel light without being brought into close contact with the dry film.

After exposure, if a support exists on the photosensitive resin layer, after removing the support, in the development step, remove the photosensitive resin layer other than the cured part by wet development, dry development, etc. A resist pattern is formed. In the present invention, wet development is preferred because it is cost effective.

In the case of wet development, development is performed using a developer such as an alkaline aqueous solution by a known method such as spraying, oscillating immersion, brushing, or scraping. As the developer, one that is safe, stable, and has good operability is used, such as a dilute solution (0.2% by mass aqueous solution) of sodium carbonate at 20 to 50°C.

In the sandblasting process, the obtained resist pattern is used as a mask material, and an abrasive is sprayed to cut the part of the object made of carbon fiber reinforced plastic where the resist pattern is not formed. Various known abrasives (blasting materials) are used for sandblasting, such as inorganic compounds such as silica and glass; metal compounds such as steel, stainless steel, zinc, and copper; garnet, zirconia, silicon carbide, Ceramics such as alumina and boron carbide; particles having an average particle size of about 2 to 100 μm, such as particles mainly composed of dry ice, etc., are used.

After cutting the object to be processed using an abrasive, a stripping process is performed in which the resist pattern is removed from the object to be processed made of carbon fiber reinforced plastic using a stripping liquid. Examples of the stripping solution used in the stripping step include aqueous solutions of alkali metal hydroxides such as sodium hydroxide, basic compounds such as N-methyldiethanolamine, pyridine, and piperidine, and the like. Note that instead of using a stripping solution, there is also a method of directly removing the photosensitive resin layer by hand or using an adhesive tape, or a method of burning off the photosensitive resin layer at high temperature.

The present invention will be explained in more detail below with reference to Examples, but the present invention is not limited to these Examples.

(Examples 1 to 4, Comparative Examples 1 to 3)
Each component shown in Table 1 was mixed to prepare a coating solution for a photosensitive resin layer. The unit of the amount of each component in Table 1 represents parts by mass. The obtained coating liquid was applied onto a polyethylene terephthalate (PET) film (trade name: R310, 25 μm thick, manufactured by Mitsubishi Chemical Corporation, support) using an applicator, and dried at 80°C for 8 minutes. Then, the solvent component was evaporated, a photosensitive resin layer (dry film thickness: 70 μm) was provided on one side of the PET film, and a polyethylene film (trade name: GF1, 30 μm thick, Tamapoly) was placed on the photosensitive resin layer as a cover film. DFRs of Examples 1 to 4 and Comparative Examples 1 to 3 were obtained by laminating the DFRs of Examples 1 to 4 and Comparative Examples 1 to 3. In addition, in Comparative Example 1, the coating liquid phase-separated and could not be mixed uniformly, so that DFR with good surface quality could not be obtained.

In Table 1, each component is as follows.
(A-1); Cellulose acetate phthalate (mass average molecular weight 61000, acid value 200mgKOH/g)
(A-2); Hydroxypropyl methyl cellulose phthalate (manufactured by Shin-Etsu Chemical Co., Ltd., mass average molecular weight 45,000, acid value 120 mgKOH/g)
(B-1) 2-(o-chlorophenyl)-4,5-diphenylimidazole dimer (B-2) 4,4'-bis(diethylamino)benzophenone (C-1) Shiko (registered trademark) UV-3000B (Urethane acrylate manufactured by Mitsubishi Chemical Corporation)
(C-2) DURA-167 (carboxy group-containing urethane acrylate manufactured by Kyoeisha Chemical Co., Ltd.)
(D-1); Copolymer resin obtained by copolymerizing methyl methacrylate/n-butyl acrylate/methacrylic acid at a mass ratio of 58/15/27 (mass average molecular weight 30,000)

Next, a dry carbon plate made of pitch-based carbon fibers with a thickness of 3 mm and a size of 15 cm x 15 cm was prepared as a target object made of carbon fiber reinforced plastic to be subjected to sandblasting. The DFR cover film obtained in Examples 1 to 4 and Comparative Examples 2 and 3 was peeled off from one side of this dry carbon, and the surface of the photosensitive resin layer was coated with a laminator at a temperature of 100°C and a pressure of 0.2 MPa. Laminated. Next, the DFR attached to the dry carbon was exposed to light using a high-pressure mercury lamp (85 mJ/cm ² ) through a photomask having nine circular patterns each having a diameter of 1 mm. Next, the DFR PET film was peeled off, and alkaline development was performed using a 0.2% sodium carbonate aqueous solution to remove the photosensitive resin layer in the non-exposed areas. Next, using 100 mesh silicon carbide, the plate-shaped dry carbons of Examples 1 to 4 and Comparative Examples 2 and 3 were sandblasted to make holes from above the resist pattern at a cutting speed of 1 second/mm ( sandblasting) and drilling at 9 points.

OPP adhesive tape (manufactured by Nitto Denko CS System Co., Ltd., trade name "EA-3925") was attached to the dry carbon plates of Examples 1 to 4 and Comparative Examples 2 and 3 after sandblasting, and a resist was applied. I tried peeling off the pattern. As a result, in Examples 1 to 4, the resist pattern could be peeled off, but in Comparative Examples 2 and 3, it was very difficult to peel off, and the resist pattern was broken before being peeled off from the dry carbon, causing the resist pattern to peel off. could not be completely removed.

The present invention can provide a method for processing an object made of carbon fiber reinforced plastic by sandblasting without leaving any residue.

Claims (1)

(A) an alkali-soluble cellulose derivative, (B) a photopolymerization initiator, and (C) a urethane (meth)acrylate compound, and (D) a carboxy group-containing acrylic resin on an object made of carbon fiber reinforced plastic. A resist pattern is formed on the object to be processed by laminating a substantially free photosensitive resin layer, imagewise exposing the photosensitive resin layer, and removing the non-exposed areas with an alkaline developer. After forming the resist pattern, the object to be processed is subjected to sandblasting through the resist pattern.