JP5631795B2 - Method for forming coating film containing magnetic flakes - Google Patents

Description

  The present invention relates to a magnetic flake-containing coating film forming method capable of forming a coating film by expressing a desired pattern on the surface of a resin coated article.

  Conventionally, by placing a sheet magnet (plate magnet) on the back side of the painted surface of the product to be coated and applying a paint containing magnetic flakes on the painted surface, the magnetic flakes in the paint are oriented and magnetized. There is known a coating method for expressing a pattern corresponding to the shape of the film (for example, see Patent Document 1). In this coating method, a single-sided magnetic pole magnet is arranged on the back surface of the article to be coated, and a coating containing magnetic flakes is applied to the surface of the article to be coated in a state where a predetermined magnetic field is formed. It is applied by a machine, the paint is cured, and a pattern is developed at the position corresponding to the magnet end surface corresponding to the outline of the magnet. Various paints for pattern formation containing a thermoplastic resin, a low boiling point solvent, a high boiling point solvent, and the like have been proposed as the paint containing the magnetic flakes (for example, Patent Document 2 and Patent Document 3).

JP 2009-154034 A JP 2007-291144 A Japanese Patent Laid-Open No. 2003-176252

  However, in the pattern formation using the above-mentioned conventional paint, there is a contrast that the outline of the pattern is bright and the other portions are dark, but only the outline is bright, so that the three-dimensional effect is insufficient. is there.

  In addition, in the conventional configuration using a single-sided double-sided magnet, when the magnetic flux density at the position corresponding to the magnet end surface is set high, the magnetic flakes stand up and harden over a wide range during coating. There is also a problem that a phenomenon (hereinafter referred to as “brightness”) in which flakes appear from the surface of the coating film and the surface of the coated product is rough occurs.

  The object of the present invention is to overcome the above-mentioned problems and to develop a super-three-dimensional appearance corresponding to the shape of the magnet, while preventing glossiness and improving the texture of the coated product surface. It is providing the containing coating-film formation method, a magnetic substance flake containing coating film, and a coated article.

  In the present invention, a plate-like magnet capable of forming a magnetic field on the surface of a plate-like article to be coated is disposed on the back surface of the article to be coated, and an acrylic resin, nitrocellulose and a magnetic substance are provided on the surface of the article to be coated. It contains flakes, the solid content of nitrocellulose is 50 to 110 parts by mass with respect to 100 parts by mass of the acrylic resin solids, and the content of magnetic flakes is 100 total resin solids of acrylic resin and nitrocellulose. The coating of 3 to 50 parts by mass with respect to parts by mass is diluted with an organic solvent so that the coating solid content is 3 to 25% by mass, and is applied so that the dry film thickness is 3 to 25 μm. The present invention provides a method for forming a coating film containing magnetic flakes, wherein a coating film expressing a pattern corresponding to the shape is formed.

  According to the method for forming a coating film containing magnetic flakes of the present invention, it is possible to improve the texture of the surface of a coated product by preventing glossiness while developing a super three-dimensional effect corresponding to the shape of the magnet.

  Hereinafter, the magnetic flake-containing coating film forming method of the present invention will be described in more detail.

  In the present invention, the article to be coated that can be coated is a plate-like nonmagnetic material. As the article to be coated, for example, a vehicle cover part made of a resin plate having a thickness of 2 to 3 mm can be used. The resin plate may be made of a material such as ABS resin, and may be subjected to pretreatment, base coating, or the like, or a conductive primer layer may be formed. The surface of the article to be coated usually has a color different from the paint color of the finished product, but the surface may be coated with the paint of the finished product color or colored with a pigment blended in the molding material. It may be. The article to be coated may be formed of various resins including rubber, FRP and the like in addition to resins such as ABS resin.

  In the present invention, an acrylic resin, magnetic flakes are formed on the surface of the article to be coated in a state where a plate-like magnet capable of forming a magnetic field on the surface of the article to be coated is disposed on the back surface of the article to be coated. And a paint containing nitrocellulose.

  The acrylic resin is an acrylic copolymer obtained by copolymerizing a monomer mixture containing an acrylate monomer and / or a methacrylate monomer according to a conventional method. Examples of monomers that can be used include methyl (meth) acrylate, ethyl (meth) acrylate, n-propyl (meth) acrylate, isopropyl (meth) acrylate, n-butyl (meth) acrylate, isobutyl (meth) acrylate, tert -Butyl (meth) acrylate, 2-ethylhexyl acrylate, n-octyl (meth) acrylate, lauryl (meth) acrylate, cyclohexyl (meth) acrylate, isobornyl (meth) acrylate, tridecyl (meth) acrylate, stearyl (meth) acrylate, etc. C1-C24 alkyl (meth) acrylate; 2-hydroxyethyl (meth) acrylate, hydroxypropyl (meth) acrylate, 2,3-dihydroxybutyl (meth) acrylate A monoesterified product of polyhydric alcohol such as 4-hydroxybutyl (meth) acrylate and polyethylene glycol mono (meth) acrylate and acrylic acid or methacrylic acid, or ring-opening polymerization of ε-caprolactone to the monoesterified product Hydroxyl group-containing polymerizable unsaturated monomers such as compounds; carboxyl group-containing polymerizable unsaturated monomers such as acrylic acid, methacrylic acid, maleic acid, and maleic anhydride; epoxy group-containing polymerizable unsaturated monomers such as glycidyl (meth) acrylate; Acrylonitrile, methacrylonitrile, vinyl acetate, Veova monomer (manufactured by Shell Chemical Co., Ltd.), styrene, vinyl toluene, α-methylstyrene; 2- (2′-hydroxy-5′-methacryloyloxyethylphenyl) -2H-benzotriazole, 4 -(Meta) Roiruokishi 1,2,2,6,6 ultraviolet absorbing property such as pentamethylpiperidine or UV stability polymerizable unsaturated monomer. These compounds can be used alone or in combination of two or more. Here, “(meth) acrylate” means “acrylate or methacrylate”.

  In the case where a polyisocyanate compound is blended in the coating material as a curing agent, or when an isocyanate-curing clear coating material is applied on the coating film made of the coating material, the acrylic resin desirably has a hydroxyl group.

  The polymerization method for polymerizing the monomer components to obtain a copolymer is not particularly limited, and is a polymerization method known per se, for example, using a solution polymerization method in the presence of a radical polymerization initiator. Can do.

  The resulting acrylic resin generally has a glass transition temperature of 20 to 90 ° C, preferably 30 to 70 ° C; generally a weight average molecular weight of 3,000 to 100,000, preferably 5,000 to 50,000 and generally 160 mg KOH / g. Hereinafter, it preferably has a hydroxyl value of 30 to 150 mgKOH / g.

  The magnetic flakes are fine powders in the form of scales or thin plates that are oriented (change direction) by a magnetic force when mixed in a liquid and subjected to a magnetic field, and have a high content of iron, nickel, iron, for example. Examples include powders of metals or metal oxides such as stainless steel, cobalt, chromium, and iron oxide; and resin powders coated or contained with these metals or metal oxides. These may be used alone or in combination of two or more. be able to.

  Content of the said magnetic body flakes can be 3-50 mass parts with respect to 100 mass parts of total resin solid content of an acrylic resin and nitrocellulose, Preferably it can be 10-35 mass parts. If the content is out of this range, the expression of the three-dimensional pattern becomes insufficient, which is not desirable.

  The nitrocellulose is not particularly limited, and a known nitrocellulose conventionally used in the paint field can be used.

  The content of the nitrocellulose is 50 to 110 parts by mass, preferably 60 to 100 parts by mass with respect to 100 parts by mass of the acrylic resin as a solid content. If the content is out of this range, the expression of the three-dimensional pattern becomes insufficient, which is not desirable.

  The coating material further contains an organic solvent, and can be used to dilute to a coating solid content described later. As the organic solvent, a solvent known per se can be used without any particular limitation. For example, aromatic hydrocarbons, aliphatic hydrocarbons, alcohols, ketones, esters, ethers, glycol ethers, etc. These may be used alone or in combination of two or more.

  Other paint components and curing agents can be blended with the paint as necessary. Examples of other resin components include polyester resin, cellulose acetate butyrate, ethylene-vinyl acetate resin, and examples of the curing agent include polyisocyanate compounds.

  If necessary, the coating material further includes pigments such as resin particles, colored pigments, bright pigments, extender pigments; ultraviolet absorbers, light stabilizers, antioxidants, surface conditioners, pigment dispersants, curing catalysts, etc. These paint additives can be combined in an appropriate combination.

  In the present invention, the paint is diluted with an organic solvent so that the coating solid content is 3 to 25% by mass, preferably 5 to 15% by mass, and the dry film thickness is 3 to 25 μm, preferably 7 to 15 μm. Is applied to form a coating film expressing a pattern corresponding to the contour shape of the magnet. When the coating solid content is lower than 3% by mass, the productivity is lowered. On the other hand, when the coating solid content is higher than 25% by mass, the film thickness distribution is generated and the pattern expression becomes unstable. On the other hand, if the dry film thickness is less than 3 μm, the masking is insufficient and the pattern is not stable.

  The paint can be applied by a normal method, for example, air spray coating, airless spray coating, brush coating, etc., and in spray coating, rotary atomization coating, etc., by applying electrostatic force. You can also.

The coating film is formed from the center part to the end part of the plate-shaped magnet along the back surface of the article to be coated. In general, it has an orientation angle of 60 ° or less, and more than 90% of the magnetic flakes preferably have an orientation angle of 45 ° or less with respect to the coating surface (as 0 °) . By aligning the magnetic flakes so as to be in such an orientation state, it is possible to obtain a coating film that expresses a super three-dimensional effect.

  Furthermore, in the present invention, the plate-shaped magnets along the back surface of the article to be coated are a first magnet having N and S poles or S and N poles on the front and back, and the back surface of the first magnet. By using a magnet having a second magnet along the contours thereof so that the N and S poles are reversed, the pattern corresponding to the shape of the magnet is clarified and glossy. Can be prevented.

  A plate-like magnet is usually a magnet sheet having a plate thickness of about 0.1 to 2.0 mm, and a large number of fine magnetic particles are kneaded into a molding material such as rubber to form a sheet. This is a known magnetic sheet obtained by magnetizing particles.

  In the present invention, a clear paint may be further applied onto the coating film as necessary, and the magnets may be attached, or the magnets may be removed and dried at the same time.

  The clear paint contains a known resin component and an organic solvent, and further contains a color pigment, a matting agent, an ultraviolet absorber, a light stabilizer, etc. as necessary. The thing which has a transparency which can permeate | transmit a coating film and can visually recognize the magnetic pattern feeling of a lower layer coating film can be used. Examples of the resin component include acrylic resins, polyester resins, alkyd resins, fluororesins, urethane resins, and silicon-containing resins containing a crosslinkable functional group such as a hydroxyl group, a carboxyl group, a silanol group, and an epoxy group. Can be used in combination with crosslinkers such as melamine resin, urea resin, (block) polyisocyanate compound, epoxy compound, carboxyl group-containing compound, acid anhydride, alkoxysilane group-containing compound that can react with these functional groups Can do.

  The clear coating can be applied by a method known per se, for example, air spray coating, airless spray coating, brush coating, etc., and electrostatic coating is applied in coating such as spray coating or rotary atomization coating. Can also be done. The resulting clear coating film has a dry film thickness of usually 5 to 100 μm, preferably 20 to 50 μm.

  Hereinafter, the present invention will be described more specifically with reference to examples. “Part” and “%” indicate “part by mass” and “% by mass” unless otherwise specified.

Preparation of paint containing magnetic flakes Preparation examples 1-10
Each component was sequentially blended according to the blending composition shown in Table 1 below, mixed and stirred, and dispersed for 30 minutes to obtain each paint (main agent) having a nonvolatile content of 18%. Dilution solvent shown in Table 1 was added to this, and it adjusted to each coating solid content, and produced each coating material (1)-(10) before coating. (Note 1) to (Note 8) in Table 1 are as follows.
(Note 1) Acrylic resin solution A: A 55% solid solution of acrylic resin having a glass transition temperature of 33 ° C., a weight average molecular weight of 10,000, and a hydroxyl value of 82.
(Note 2) Acrylic resin solution B: 60% solid solution of acrylic resin having a glass transition temperature of 60 ° C., a weight average molecular weight of 20,000, and a hydroxyl value of 73.
(Note 3) Nitrocellulose A: “HIG 1 / 2A”, trade name, manufactured by SNP Japan, industrial nitrified cotton.
(Note 4) Nitrocellulose B: “HIG 20”, trade name, manufactured by SNP Japan, industrial nitrified cotton.
(Note 5) Cellulose acetate butyrate: “CAB551”, trade name, manufactured by Eastman Chemical Company.
(Note 6) Iron flakes: “Stapa TA Ferricon 200”, trade name, manufactured by ECKART, 70% solid content paste.
(Note 7) Stainless steel flake: “Stainless steel paste”, trade name, manufactured by Toyo Aluminum Co., Ltd., solid content 90% paste.
(Note 8) Curing agent: “Desmodule N3300”, trade name, manufactured by Sumika Bayer Urethane Co., Ltd., polyisocyanate curing agent.

Examples and comparative examples Example 1
A 0.4 mm thick magnet sheet (A) with a character pattern formed on the back surface of a 2.5 mm thick ABS resin plate, and “Shelltron PR450” (5 μm in dry film thickness on the surface) The product name, manufactured by Kawakami Paint Co., Ltd., solvent-type conductive primer) was applied by air spray and allowed to stand for 30 seconds. On top of that, the paint (1) obtained in Production Example 1 was spray-coated so as to have a dry film thickness as shown in Table 2 below. Next, after drying the surface of the coating film with a finger, “Letane PG2K Clear M” (trade name, manufactured by Kansai Paint Co., Ltd., acrylic urethane resin-based clear paint) is spray-coated to a dry film thickness of 30 μm. And heated at 75 ° C. for 30 minutes after standing for 5 to 10 minutes. After heating and drying, the ABS plate was cooled to room temperature, and the magnet sheet on the back surface was removed to obtain a painted plate.

Examples 2-5 and Comparative Examples 1-5
In Example 1, each coated plate was obtained in the same manner as in Example 1 except that the paint shown in Table 2 below was used as the magnetic substance-containing paint.

Examples 6-10
In the first embodiment, instead of the magnet sheet (A), the first magnet sheet having the N pole and the S pole, and the second along the contour so that the N pole and the S pole are reversed with respect to the back surface thereof. Each coated plate was obtained in the same manner as in Example 1 except that the magnetic sheet (B) combined with the magnetic sheet was used.

Evaluation test The three-dimensional effect of the magnetic pattern was visually evaluated according to the following criteria for each of the obtained coated plates. Further, the orientation angle of the magnetic material in the magnetic flake-containing coating was measured by cutting the cross section of the coating and using an optical microscope. Further, the initial adhesion and water resistance of each coated plate were evaluated as follows. The results are shown in Table 2 below.
(* 1) Three-dimensional effect of magnetic pattern:
(Visual evaluation criteria)
◎: The pattern can be confirmed from a place 5 m away from the room, and the angle at which the board is viewed is the front (90
Level that feels the three-dimensionality and depth of the pattern when it is changed from (degree) to diagonal (15 degrees).
○: The pattern can be confirmed from a location 2 m away from the room, and the angle at which the board is viewed is the front (90
Level that feels the three-dimensionality and depth of the pattern when it is changed from (degree) to diagonal (15 degrees).
△: It is difficult to see the pattern from a place 2m away in the room, but the pattern can be confirmed when it approaches 50cm, and when the angle of viewing the board is changed from the front (90 degrees) to the diagonal (15 degrees),
A level where you can feel the three-dimensionality and depth of the pattern.
×: Level at which the pattern can be confirmed from a location 2 m away in the room, but the contour of the pattern is too clear and the stereoscopic effect is poor.
(Measurement method of orientation angle)
Cut the coated plate with a cutter so that the edge is obtained from the central part of the magnet pattern of each painted plate, and the cross section is magnified 100 times with an optical microscope so that the magnetic flakes are oriented horizontally. As an angle, the orientation angle of the magnetic flakes from the center to the end of the pattern was measured.
(* 2) Initial adhesion:
Cut a cut line with a cutter to reach the substrate in the magnet pattern part and general part of each test paint, make 100 squares with a size of 1 mm x 1 mm, stick adhesive cellophane tape on the surface, 20 The number of residual coatings on the pattern portion and the general portion of the grid after the rapid peeling at 0 ° C. was examined.
○: 100 (no peeling)
Δ: 99-50 pieces ×: 49 pieces or less.
(* 3) Water resistance:
Each test coating is dipped in warm water at 40 ° C. for 10 days, pulled up and dried, and then an adhesion test is performed in the same manner as the initial adhesion test described above. Each film number was examined and evaluated in the same manner as described above.

Claims (4)

A plate-like magnet capable of forming a magnetic field on the surface of the plate-like article to be coated is disposed on the back surface of the article to be coated, and the surface of the article to be coated contains acrylic resin, nitrocellulose and magnetic flakes. The solid content of nitrocellulose is 50 to 110 parts by mass with respect to 100 parts by mass of the solids of acrylic resin, and the content of magnetic substance flakes is 100 parts by mass of the total resin solids of acrylic resin and nitrocellulose. The paint which is 13 to 35 parts by mass was diluted with an organic solvent so that the coating solid content would be 3 to 25% by mass and applied to a dry film thickness of 3 to 25 μm, corresponding to the contour shape of the magnet. A method for forming a coating film containing magnetic flakes, which comprises forming a coating film expressing a pattern.   A plate-shaped magnet is a plate-shaped magnet along the back surface of the article to be coated, the first magnet having N and S poles, or S and N poles on the front and back, and the back surface of the first magnet On the other hand, the method according to claim 1, further comprising: a second magnet along which the contours match so that the N pole and the S pole are reversed.   From the center part to the end part of the plate-shaped magnet along the back surface of the article to be coated, substantially all of the magnetic flakes present in the dry coating film have an orientation angle of 60 ° or less with respect to the coating surface. A magnetic flake-containing coating film obtained by the method according to claim 1 or 2.   The coated article obtained by the method of Claim 1 or 2.