JP2006070169A - Active energy beam-curing type aqueous undercoating composition for metal vapor deposition - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an active energy beam-curing type aqueous undercoat composition excellent in close adherence with an FRP base material, surface smoothness and heat resistance for forming a mirror plane by vacuum deposition on the surface of the FRP base material. <P>SOLUTION: This active energy beam-curing type aqueous undercoat composition for FRP metal vapor deposition is characterized by containing (A) water-soluble or dispersible alkyd resin having 10-50% oil length and 10-100 acid value, (B1) a monomer having (meth)acryloyl group and carboxy group in its molecule, (B2) a monomer having ≥2 (meth)acryloyl groups and without having carboxy group in its molecule and (C) a photopolymerization initiator. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to an active energy curable aqueous undercoat composition for FRP metal vapor deposition that is excellent in adhesion and heat resistance.

  In a reflector such as an automobile, a molded body is formed using FRP, and a target object is produced by vacuum-depositing a metal such as aluminum on the surface thereof. However, the surface of the FRP material is poor in smoothness and also has insufficient adhesion to a vapor deposition layer such as aluminum, and it is difficult to directly vacuum deposit with aluminum or the like.

  Therefore, an undercoat agent having excellent adhesion to the FRP surface and adhesion to aluminum is required. First, the undercoat agent is required to have smoothness and specularity on the surface of the coating film, and further, heat resistance is also required.

  As a composition for undercoat, a (meth) acrylic monomer having a solvent-type amino group, a polyfunctional monomer having three or more (meth) acryloyloxy groups in one molecule, and a photopolymerization initiator A composition comprising a solvent-type alkyd resin, a monomer having at least two (meth) acryloyl groups, and a photopolymerization initiator and, if necessary, an amino resin. A thing (for example, refer patent document 2) etc. is proposed.

  In recent years, interest from solvent-based paints to water-based paints has increased due to the strengthening of VOC regulations and the trend of improving the working environment.

Japanese Patent No. 3266705 WO 1995/032250 publication

  An object of the present invention is to provide an active energy ray-curable aqueous undercoat composition that is excellent in adhesion to the FRP material, smoothness of the surface, and heat resistance for forming a mirror surface on the surface of the FRP material by vacuum deposition. It is in.

  As a result of intensive studies to solve the above problems, the present inventors have found an active energy ray-curable aqueous undercoat composition containing the alkyd resin, monomer and photopolymerization initiator specified in the present invention as essential components. Has been found to be advantageously achieved, and the present invention has been completed.

  That is, the present invention is primarily a water-soluble or water-dispersible alkyd resin (A) having an oil length of 10 to 50% and an acid value of 10 to 100, and a monomer having a (meth) acryloyl group and a carboxyl group in the molecule. (B1), a monomer (B2) having two or more (meth) acryloyl groups in the molecule and no carboxyl group, and a photopolymerization initiator (C), the alkyd resin (A) described above And the ratio (A) :( B1 + B2) of the sum (B1 + B2) of the monomers (B1) and (B2) described above is 30:70 to 70:30, and the monomer (B1) described above, A ratio of monomer (B2), (B1) :( B2) is 10:90 to 60:40, a curable aqueous undercoat composition selected from active energy rays for metal deposition of FRP, provide.

  Secondly, the present invention relates to a water-soluble or water-dispersible alkyd resin (A) having an oil length of 10 to 50% and an acid value of 10 to 100, a monomer (B1) having a (meth) acryloyl group and a carboxyl group in the molecule. ), A monomer (B2) having two or more (meth) acryloyl groups in the molecule and no carboxyl group, and a photopolymerization initiator (C) are mixed and water is gradually added to emulsify the phase. The manufacturing method of the active energy ray hardening-type aqueous undercoat composition for FRP metal vapor deposition characterized by having a process is provided.

  Thirdly, the present invention provides a cured coating layer of the active energy ray-curable aqueous undercoat composition for FRP metal deposition, a metal thin film layer obtained by vacuum deposition, and a clear coating layer on the surface of an FRP molded body for an automobile reflector. Are provided in this order.

ADVANTAGE OF THE INVENTION According to this invention, the active energy ray which is excellent in the adhesiveness to the FRP raw material surface, a cured coating film has smoothness, can form the mirror surface excellent in the external appearance at the time of aluminum vapor deposition, and is excellent also in heat resistance. A curable aqueous undercoat composition can be provided.

The active energy ray-curable aqueous undercoat composition for FRP metal deposition of the present invention will be described in detail.

The alkyd resin (A) used in the active energy ray-curable aqueous undercoat composition for FRP metal deposition according to the present invention is a water-soluble or water-dispersible alkyd resin having an oil length of 10 to 50% and an acid value of 10 to 100. is there.

The production method of the alkyd resin (A) used in the present invention is not particularly limited, and known methods such as a transesterification method using oil as a raw material and a fatty acid method using fatty acid as a raw material can be used.

Examples of the oil component of the alkyd resin (A) used in the present invention include sesame oil, (dehydrated) castor oil, tung oil, soybean oil, safflower oil, sunflower oil, rice bran oil, tall oil, coconut oil, palm kernel oil, and the like. There is. These oils are used alone or in combination of two or more.

In addition, as the fatty acid component of the alkyd resin (A) used in the present invention, the above-mentioned oil component fatty acid, caprylic acid, capric acid, lauric acid, myristic acid, palmitic acid, stearic acid, oleic acid, ricinoleic acid, linoleum There are acids, linolenic acid, eleostearic acid and the like. These fatty acids are used alone or in combination of two or more. Furthermore, methyl ester compounds of these fatty acids can also be used.

As other monobasic acids, benzoic acid, pt-butylbenzoic acid, abietic acid, hydrogenated abietic acid, and the like can also be used.

Polybasic acids include (anhydrous) phthalic acid, isophthalic acid, terephthalic acid, 2,6-naphthalenedicarboxylic acid, aromatic dibasic acids such as 5-sodium sulfoisophthalic acid, (anhydrous) succinic acid, alkenyl (anhydrous) Aliphatic dibasic acids such as succinic acid, fumaric acid, (anhydrous) maleic acid, itaconic acid, adipic acid, sebacic acid, azelaic acid, (anhydrous) hymic acid, (anhydrous) trimellitic acid, (anhydrous) pyromellitic acid , (Anhydrous) methylcyclohexene carboxylic acid, benzophenone tetracarboxylic acid and the like. These polybasic acids are used alone or in combination of two or more.

Examples of the polyhydric alcohol used in the alkyd resin (A) used in the present invention include ethylene glycol, propylene glycol, 1,3-butanediol, 1,5-pentanediol, 1,6-hexanediol, and 1,9-nonane. Diol, 2-methyl-1,8-octanediol, neopentyl glycol, diethylene glycol, triethylene glycol, dipropylene glycol, tripropylene glycol, (poly) tetramethylene glycol, 1,4-cyclohexanediol, 1,4-cyclohexane Dihydric alcohols such as dimethanol, hydrogenated bisphenol A, spiroglycol, tricyclodecane dimethanol, trihydric alcohols such as glycerin, trimethylolpropane, trimethylolethane, pentaerythritol, diglycol Phosphorus, ditrimethylolpropane, di-trimethylol ethane, there is a tetravalent or more alcohols such as dipentaerythritol. These may be used alone or in combination of two or more.

The oil length of the alkyd resin (A) used in the present invention is in the range of 10 to 50%, preferably in the range of 15 to 40%. When the oil length is less than 10%, the smoothness is lowered, and when the oil length exceeds 50%, the curability tends to be lowered.

The acid value of alkyd resin (A) used for this invention is the range of 10-100, Preferably it is the range of 20-70. If the acid value is less than 10, it is difficult to make it water-based, and if it exceeds 100, the water resistance tends to be inferior.

The number average molecular weight of the alkyd resin (A) used in the present invention is usually in the range of 1,000 to 10,000, preferably 2,000 to 8,000. If it is out of this range, it may be difficult to obtain a predetermined effect.

The monomer (B1) having a (meth) acryloyl group and a carboxyl group in the molecule used in the present invention is an active energy ray-curable component and improves the stability of the paint.

For example, as this monomer (B1), 2- (meth) acryloyloxyethyl succinic acid, 2- (meth) acryloyloxypropyl succinic acid, 2- (meth) acryloyloxyethylphthalic acid, 2- (Meth) acryloyloxyethyl hexahydrophthalic acid, 2- (meth) acryloyloxypropyl phthalic acid, ω-carboxy-polycaprolactone mono (meth) acrylate, monohydroxyethyl phthalate (meth) acrylate, 2- (meta ) Acryloyloxypropylphthalic acid, EO-modified succinic acid (meth) acrylate, β-carboxyethyl (meth) acrylate, acrylic acid dimer, and the like. These may be used alone or in combination of two or more.

The monomer (B2) having two or more (meth) acryloyl groups in the molecule used in the present invention is an active energy ray-curable component and increases the crosslink density of the coating film.

As this monomer (B2), 1,3-butanediol di (meth) acrylate, 1,4-butanediol di (meth) acrylate, neopentyl glycol di (meth) acrylate, EO-modified neopentyl glycol di ( (Meth) acrylate, PO-modified neopentyl glycol di (meth) acrylate, 1,6-hexanediol di (meth) acrylate, EO-modified 1,6-hexanediol di (meth) acrylate, 1,4-heptanediol di (meth) ) Acrylates, alkyl-type (meth) acrylates such as 1,9-nonanediol di (meth) acrylate, spiroglycol di (meth) acrylate; ethylene glycol di (meth) acrylate, diethylene glycol di (meth) acrylate, triethylene glycol Di (meta) Chryrate, tetraethylene glycol di (meth) acrylate, polyethylene glycol di (meth) acrylate, propylene glycol di (meth) acrylate, dipropylene glycol di (meth) acrylate, tripropylene glycol di (meth) acrylate, 1,3-butylene Alkylene glycol type (meth) acrylates such as glycol di (meth) acrylate; hydroxypivalate ester neopentyl glycol di (meth) acrylate, caprolactone-modified hydroxypivalate ester neopentyl glycol di (meth) acrylate and other ester types (meta ) Acrylates; trimethylolpropane di (meth) acrylate, EO-modified trimethylolpropane di (meth) acrylate, PO-modified trimethylo Propane di (meth) acrylate, caprolactone modified trimethylolpropane di (meth) acrylate, trimethylolpropane tri (meth) acrylate, EO modified trimethylolpropane tri (meth) acrylate, PO modified trimethylolpropane tri (meth) acrylate, caprolactone modified Trimethylolpropane type (meth) acrylates such as trimethylolpropane tri (meth) acrylate, hydroxypropylated trimethylolpropane tri (meth) acrylate, HPA-modified trimethylolpropane tri (meth) acrylate, ditrimethylolpropane tetraacrylate, etc .; penta Erythritol tri (meth) acrylate, pentaerythritol tetra (meth) acrylate, dipentaerythritol hexa ( Pentaerythritol type (meth) acrylates such as (meth) acrylate, monohydroxypentaerythritol tri (meth) acrylate, caprolactone-modified dipentaerythritol hexaacrylate; isocyanuric acid EO-modified di (meth) acrylate, isocyanuric acid PO-modified type Isocyanuric acid type (meth) acrylates such as tri (meth) acrylate; alicyclic di (meth) acrylates such as dicyclopentanyl di (meth) acrylate and ethoxylated hydrogenated bisphenol A di (meth) acrylate; Examples include hydroxyl group-containing (meth) acrylates such as 2-hydroxyethyl di (meth) acrylate, hydroxypropyl di (meth) acrylate, and diethylene glycol bis (hydroxypropyl di (meth) acrylate). That. These may be used alone or in combination of two or more.

  From the viewpoint of curability of the coating film, it is preferable to use at least one or more of the above-mentioned monomers (B2) having 3 or more (meth) acryloyl groups in the molecule.

  Examples of the photopolymerization initiator (C) used in the present invention include ketoxyacetophenone, 2-hydroxy-2-methyl-1-phenylpropan-1-one from heat resistance, adhesion, curability, and yellowing resistance. 1- (4-isopropylphenyl) -2-hydroxy-2-methylpropan-1-one, 1- (4-dodecylphenyl) -2-hydroxy-2-methylpropan-1-one, 4- (2- Acetophenones such as hydroxy-2-propyl) ketone, 1-hydroxycyclohexyl phenylketone, 2-methyl-1- [4- (methylthio) phenyl] -2-morpholinopropane-1; benzoin, benzoin methyl ether, benzoin ethyl ether Benzoin isopropyl ether, benzoin isobutyl ether, benzyl dimethyl ketal, etc. Zoins; benzophenones such as benzophenone, benzoylbenzoic acid, 4-phenylbenzophenone, hydroxybenzophenone, acrylated benzophenone, 4-benzoyl-4'-methyldiphenyl sulfide; thioxanthone, 2-methylthioxanthone, 2,4-dimethylthioxanthone, Thioxanthones such as 2,4-diethylthioxanthone and 2,4-diisopropylthioxanthone; Acylphosphine oxides such as 2,4,6-trimethylbenzoyldiphenylphosphine oxide; Glyoxyesters such as methylphenylglyoxylate It is done. These may be used alone or in combination of two or more.

  In the active energy ray-curable aqueous undercoat composition for FRP metal deposition of the present invention, the ratio of the alkyd resin (A) and the sum of the monomers (B1) and (B2) (B1 + B2), (A): (B1 + B2) Is in the range of 30:70 to 70:30, preferably 40:60 to 60:40. When the amount of alkyd resin (A) is larger than this range, the curability tends to decrease, and when the amount of alkyd resin (A) is smaller than this range, the smoothness of the coating film tends to decrease.

  The ratio of the monomer (B1) having a (meth) acryloyl group and a carboxyl group in the molecule and the monomer (B2) having two or more (meth) acryloyl groups in the molecule, (B1) :( B2) is in the range of 10:90 to 60:40, more preferably in the range of 20:80 to 40:60. If the monomer (B1) is more than this range, sufficient curability may not be obtained, and if it is less, the coating stability tends to be inferior.

  The active energy ray-curable aqueous undercoat composition for vapor deposition of FRP metal of the present invention can be used by mixing other various known and conventional resins within the scope of achieving the object of the present invention. For example, it is used in the present invention. Vinyl resins other than alkyd resins (A), polyester resins, polyurethane resins, epoxy resins, epoxy ester resins, acrylic resins, benzoguanamine resins, urea resins, phenol resins, petroleum resins, ketone resins, or modified resins thereof Can be mentioned.

  The active energy ray-curable aqueous undercoat composition for FRP metal vapor deposition according to the present invention can be used by mixing other commonly known solvents other than water within the scope of achieving the object of the present invention. Preferably, it is a water-soluble or water-soluble solvent, for example, alcohols such as methanol, ethanol, n-propyl alcohol, iso-propyl alcohol, n-butanol, iso-butanol, tert-butanol; ethylene glycol monomethyl Examples thereof include cellosolves such as ether and ethylene glycol monobutyl ether; propylene glycol ethers such as propylene glycol monomethyl ether and propylene glycol monopropyl ether. These compounds may be used alone or in combination of two or more.

  In the active energy ray-curable aqueous undercoat composition for FRP metal deposition according to the present invention, a known coating additive can be used as necessary. For example, inorganic pigments, organic pigments, extender pigments, clay minerals, surface conditioners, lubricants, thickeners, surfactants, antifoaming agents, leveling agents, antifungal agents, antibacterial agents, antistatic agents, ultraviolet absorbers, etc. Can be added.

  As a method for producing an active energy ray-curable aqueous undercoat composition for FRP metal deposition according to the present invention, a water-soluble or water-dispersible alkyd resin (A), and a single molecule containing a (meth) acryloyl group and a carboxyl group in the molecule described above. Water is gradually added after mixing the monomer (B1), the monomer (B2) having two or more (meth) acryloyl groups in the molecule and no carboxyl group, and the photopolymerization initiator (C). It can manufacture by carrying out phase inversion emulsification.

  The substrate may be subjected to a known surface treatment for further improving the adhesion of the active energy ray-curable aqueous undercoat composition for FRP metal deposition of the present invention. For example, degreasing with a solvent, corona discharge treatment, plasma treatment, flame treatment, electron beam irradiation treatment, ultraviolet ray irradiation treatment and the like may be mentioned, and a treatment combining one or more of these may be performed.

  The method of applying the active energy ray-curable aqueous undercoat composition for FRP metal deposition of the present invention to the FRP substrate is not particularly limited as long as the object of the present invention is not impaired, for example, dip coating, spray coating, A known method such as an electrostatic coating method can be used. Of these, the spray coating method is preferred. The application may be performed once, or may be performed in multiple stages of application twice or more.

  The dry film thickness of the active energy ray-curable aqueous undercoat composition for FRP metal deposition of the present invention on the FRP substrate is not particularly limited, but is usually in the range of 5 to 50 μm, preferably in the range of 10 to 40 μm. is there. After application, in order to evaporate moisture and the like, it is dried at room temperature or by heating. The heat drying is usually performed in the range of 50 to 150 ° C., preferably in the range of 80 to 120 ° C., for 30 seconds to 30 minutes, preferably 3 to 15 minutes.

  As described above, the coating film is dried and then cured with active energy rays. For example, in the case of ultraviolet curing, the composition of the present invention is cured with a total irradiation amount of about 300 to 5000 mJ using a high-pressure mercury lamp, a metal halide lamp or the like that is a known irradiation lamp.

  After being cured by the above method, a metal such as aluminum is usually vacuum-deposited to a thickness of 100 to 1000 (angstrom), and a thermosetting clear coating composed of an acrylic resin or the like is further dried to a thickness of 5 to 10 μm. Then, after painting by spray coating or the like, it is baked and dried at 80 to 140 ° C. for 10 to 30 minutes.

  As described above, a cured coating layer of the active energy ray-curable aqueous undercoat composition for FRP metal deposition specified in the present invention on the surface of an FRP molded body for an automobile reflector, a metal thin film layer and a clear coating layer obtained by vacuum deposition. By having it in this order, an FRP molded body for an automobile reflector can be obtained.

  Hereinafter, in order to facilitate understanding of the present invention, the present invention will be specifically described by way of examples. However, the present invention is not limited to the examples. In addition, the part and% in each example are based on a mass reference | standard.

Example 1
10 parts of monofunctional monomer (B1-1) (ω-carboxy-polycaprolactone monoacrylate; trade name Aronix M-5300, manufactured by Toagosei Co., Ltd.) and 3.7 parts of triethylamine for neutralization of acid value are mixed with stirring. 40 parts of monomer (B2-1) (pentaerythritol triacrylate; trade name Aronix M-305, manufactured by Toagosei Co., Ltd.) having a trifunctional group is added to the obtained liquid and stirred and mixed with a dispersion stirrer until uniform. To do. 4 parts of the photopolymerization initiator (C-1) (1-hydroxy-cyclohexyl-phenyl-ketone; trade name Irgacure 184, manufactured by Ciba Specialty Chemicals Co., Ltd.) is added thereto, and the mixture is stirred until uniform. Further, 50 parts of alkyd resin (A-1) (soybean oil-modified alkyd resin, solid content: 60%, oil length: 25%, acid value: 40 mgKOH / g) are mixed and stirred until uniform. Next, ion-exchanged water is gradually added until the solid content becomes 30%, and phase inversion emulsification is performed. Further, 0.1 part of a perfluoroalkyl group-containing nonionic oligomer (trade name; Megafac F470, manufactured by Dainippon Ink & Chemicals, Inc.) was added as a surface conditioner, and the mixture was sufficiently stirred, and an active energy ray for FRP metal deposition A curable aqueous undercoat composition was obtained.

(Examples 2-22, Comparative Examples 1-6)
In the same manner as in Example 1, an active energy ray-curable aqueous undercoat composition for FRP metal deposition was prepared with the compositions shown in Tables 1 to 4.

Mn shown in Table 1 represents the number average molecular weight. The following monomers were used for Tables 2-5. In the table, the formulation indicates the solid content ratio.
(B1-2): Acrylic acid dimer (trade name Aronix M-5600 manufactured by Toa Gosei Co., Ltd.)
(B1-3): 2-acryloyloxyethyl phthalate (trade name, Aronix M-5400, manufactured by Toagosei Co., Ltd.),
(B2-2): Ditrimethylolpropane tetraacrylate (trade name; Aronix M-408, manufactured by Toagosei Co., Ltd.),
(B2-3): Dipentaerythritol hexaacrylate (trade name; LUMICURE DPA-620, manufactured by Dainippon Ink & Chemicals, Inc.)
(C-2): 2-methyl-1 [4-methylthiophenyl] -2-morpholinopropan-1-one (trade name; Irgacure 907 manufactured by Ciba Specialty Chemicals),
(Y-1): Polyester resin (water-dispersed polyester dispersion, nonvolatile content 30%, molecular weight 15,000, acid value 3 mgKOH / g),
(Y-2): Acrylic resin (water-dispersed acrylic dispersion, nonvolatile content 35%, molecular weight 10,000, acid value 10 mgKOH / g)

(Evaluation)
About the active energy ray hardening-type aqueous undercoat composition for FRP metal vapor deposition obtained in Examples 1-22 and Comparative Examples 1-6, the coating-film external appearance, adhesiveness, and heat resistance were tested. The test film preparation and test method are as follows.

(Create coating film for test)
The FRP molded product for automobile that has been degreased is spray-coated with an air-type hand gun so that the dry film thickness is 15 to 20 μm, and dried at 100 ° C. for 10 minutes to remove moisture and the like. Next, using a 120 W / cm high-pressure mercury lamp, the coating film was cured by irradiating with ultraviolet rays at an irradiation amount of 500 mJ / cm ² . Thereafter, aluminum is vacuum-deposited on the surface of this undercoat coating film, and finally, a thermosetting solvent-type acrylic melamine paint is spray-coated to a dry film thickness of 3 to 5 μm and dried at 120 ° C. for 10 minutes in a dryer. I let you.

(Appearance of coating film)
Visually determine the appearance and inspect for defects such as cracks, blisters, whitening, and rainbows. ◎ if there is no defect and glossy, ○ if there is no defect, △ if there is a slight defect, △ Some were marked with x.

(Adhesion)
Make 100 grids with cuts at 1mm intervals on the painted surface. The cellophane adhesive tape 24 mm width was applied to the cut part from above, and it was evaluated by the number of grids remaining without peeling by abruptly peeling in the direction perpendicular to the painted surface.
A: The number of remaining grids is 100/100
○: The number of remaining grids is 99/100 to 91/100
Δ: The number of remaining grids is 51/100 to 90/100
X: The number of remaining grids is 50/100 or less

(Heat-resistant)
After leaving in a hot air circulating drying oven at 180 ° C. for 96 hours, the appearance and adhesion were evaluated by the above methods.

(water resistant)
The test panel was immersed in a constant temperature water bath at 40 ° C. for 30 hours, and after taking out, the appearance and adhesion were evaluated in the same manner as described above.

  About the said Example and a comparative example, the evaluation result of each coating film is shown in Tables 6-8.

The active energy ray-curable aqueous undercoat composition for FRP metal deposition of the present invention has excellent smoothness, adhesion, heat resistance and the like.

Claims (5)

Water-soluble or water-dispersible alkyd resin (A) having an oil length of 10 to 50% and an acid value of 10 to 100, a monomer (B1) having a (meth) acryloyl group and a carboxyl group in the molecule, ) A monomer (B2) having two or more acryloyl groups and having no carboxyl group, and a photopolymerization initiator (C), the alkyd resin (A) and the monomer (B1) ) And (B2), the ratio of the sum (B1 + B2), (A) :( B1 + B2) is 30:70 to 70:30, and the ratio of the monomer (B1) and the monomer (B2) described above (B1): (B2) is 10: 90-60: 40, The active energy ray hardening-type aqueous undercoat composition for FRP metal vapor deposition characterized by the above-mentioned. The active energy ray-curable aqueous underlayer for FRP metal deposition according to claim 1, wherein the monomer (B2) contains at least one monomer having 3 or more (meth) acryloyl groups in the molecule. Coat composition. 2. The active energy ray-curable aqueous undercoat composition for FRP metal deposition according to claim 1, wherein the alkyd resin (A) has a number average molecular weight of 1,000 to 10,000. Water-soluble or water-dispersible alkyd resin (A) having an oil length of 10 to 50% and an acid value of 10 to 100, a monomer (B1) having a (meth) acryloyl group and a carboxyl group in the molecule, ) Having a step of phase-emulsifying by gradually adding water after mixing the monomer (B2) having two or more acryloyl groups and not having a carboxyl group and the photopolymerization initiator (C). A method for producing an active energy ray-curable aqueous undercoat composition for FRP metal deposition. A cured coating layer of the active energy ray-curable aqueous undercoat composition for FRP metal deposition according to any one of claims 1 to 3, a metal thin film layer obtained by vacuum deposition, and a clear coat on a surface of an FRP molded body for an automobile reflector The FRP molded object for motor vehicle reflectors which has a layer in this order.