JP7385253B2 - Method for producing painted objects and coating compositions - Google Patents

Description

The present invention relates to a method for producing a coated article and a coating composition. More specifically, the present invention relates to a method for manufacturing a coated article having a coating film having an uneven pattern, and a coating composition for forming a coating film having an uneven pattern by spray coating.

Several coating compositions and coating methods are known that are capable of forming a coating film (cured film) having an uneven pattern without applying physical force to the substrate or coating film.

As an example, Patent Document 1 states that (1) a slurry paint using water as a medium is undercoated on the object to be coated, (2) the undercoat film is irradiated with an electron beam, etc. to a gel fraction of 7 to 7. Partially dry to a range of 40%. (3) A coating process is described in which a solvent-type top coat using an organic solvent as a medium is applied over a portion or the entire surface of the undercoat to partially swell the undercoat, and then dried to form a film. ing. According to Patent Document 1, by this method, unevenness in a zigzag pattern is formed.

As another example, claim 1 of Patent Document 2 states that the binder is polyester and/or acrylic resin, or a resin modified with a silicone resin and has a weight average molecular weight in the range of 2,000 to 10,000, and has a melting point of 110. A coating composition characterized in that the coating composition contains 0.1 to 5% of amide "aggregate" having a temperature of 170° C. and an average particle size of 15 to 200 microns. There is. The example of Patent Document 2 describes that a coating film having an uneven pattern was obtained by applying a coating composition onto a steel plate using a bar coater and baking it at 220°C.
According to Patent Document 2, by using this coating composition, a decorative metal plate with an uneven feel and a high design quality can be obtained only by a painting process without performing post-processes such as embossing. It is stated that the mechanism by which the unevenness is formed is related to the melting of the amide aggregate when the coating composition is applied to the base material and baked.

As yet another example, Patent Document 3 describes an uneven pattern forming paint in which synthetic resin particles that are insoluble in organic solvents and do not soften at baking temperatures are stably dispersed. Specifically, polyethylene resin particles are mentioned as the synthetic resin particles. These synthetic resin particles form an uneven pattern on the coating film.

Japanese Unexamined Patent Publication No. 56-121664 Japanese Patent Application Publication No. 8-120201 Japanese Unexamined Patent Publication No. 49-007341

The coating method described in Patent Document 1 requires at least two coatings, an undercoat and a topcoat, and has the disadvantage of increasing the number of steps. This is unfavorable from the viewpoint of industrial productivity.
Patent Document 2 does not include any description of forming a coating film having an uneven pattern by spray painting. In addition, since the coating composition of Patent Document 2 contains amide "aggregate", that is, amide "particles", it may be difficult to apply it to spray painting in which the coating composition is applied in the form of a fine mist. There is sex.
Patent Document 3 also has no description of forming a coating film having an uneven pattern by spray painting. Furthermore, since the paint disclosed in Patent Document 3 contains synthetic resin particles, it may be difficult to apply it to spray painting in which the paint composition is applied in the form of a fine mist.

The present inventors have conducted various studies with the aim of forming a coating film (cured film) having an uneven pattern by just one spray coating.

As a result of studies, the present inventors completed the invention provided below and solved the above problem.

According to the invention,
The coating film component includes at least a base agent, a curing agent, and a fatty acid amide, and the content of the fatty acid amide in 100 parts by mass of the coating film component is 2.5 to 15 parts by mass,
Furthermore, it contains organic solvents as volatile components,
The fatty acid amide is dissolved in the organic solvent, or is dispersed in the organic solvent as particles with a particle size of 10 μm or less, and when observed with a microscope, fatty acid amide-derived particles with a particle size of more than 10 μm are found. paint composition that is not observed ,
A method for producing a coated article is provided, which includes spray painting the surface of the coated article using a spray gun to produce a coated article having a coating film having an uneven pattern.

Further, according to the present invention,
A coating composition for forming a coating film having an uneven pattern by spray coating,
Coating film components include at least a base agent, a curing agent, and a fatty acid amide,
The content of the fatty acid amide in 100 parts by mass of the coating film component is 2.5 to 15 parts by mass,
Furthermore, it contains an organic solvent as a volatile component,
The fatty acid amide is dissolved in the organic solvent, or is dispersed in the organic solvent as particles with a particle size of 10 μm or less, and when observed with a microscope, fatty acid amide-derived particles with a particle size of more than 10 μm are found. An unobservable coating composition is provided.

Further, according to the present invention,
Using a spray gun, a coating composition containing at least a base agent, a curing agent, and a fatty acid amide as a coating film component, and in which the content of the fatty acid amide in 100 parts by mass of the coating film component is 2.5 to 15 parts by mass. a spray painting process in which the surface of the object to be coated is sprayed;
A baking process that involves heating at 60 to 180°C;
A method for producing a coated article comprising a coating film having an uneven pattern, including
is provided.

Further, according to the present invention,
Using a spray gun, a coating composition containing at least a base agent, a curing agent, and a fatty acid amide as a coating film component, and in which the content of the fatty acid amide in 100 parts by mass of the coating film component is 2.5 to 15 parts by mass. A method for producing a coated article having a coating film having an uneven pattern, which includes a spray painting process of spray painting the surface of the coated article using a method, but does not include a baking process.
is provided.

According to the present invention, a coating film (cured film) having an uneven pattern can be formed by just one spray coating.

Embodiments of the present invention will be described in detail below.

In the present specification, the notation "X to Y" in the description of numerical ranges refers to not less than X and not more than Y, unless otherwise specified. For example, "1 to 5% by mass" means "1 to 5% by mass".

In the description of a group (atomic group) in this specification, a description that does not indicate whether it is substituted or unsubstituted includes both those without a substituent and those with a substituent. For example, the term "alkyl group" includes not only an alkyl group without a substituent (unsubstituted alkyl group) but also an alkyl group having a substituent (substituted alkyl group).
In this specification, the expression "(meth)acrylic" represents a concept that includes both acrylic and methacrylic. The same applies to similar expressions such as "(meth)acrylate".
The term "organic group" as used herein means an atomic group obtained by removing one or more hydrogen atoms from an organic compound, unless otherwise specified. For example, a "monovalent organic group" refers to an atomic group obtained by removing one hydrogen atom from an arbitrary organic compound.

As used herein, the term "coating film component" refers to components other than volatile components in a coating composition (as commonly used in the technical field of coatings). In addition, unless otherwise specified, descriptions regarding the content and ratio of coating film components such as base agent, curing agent, fatty acid amide, etc. refer to the content and ratio of each coating film component itself (non-volatile content not including solvent). .

<Method for manufacturing painted objects/paint composition>
In the method for producing a coated article of the present embodiment, a coated article having a coating film having an uneven pattern is produced by spray painting a specific coating composition onto the surface of the coated article using a spray gun.
The above-mentioned "specific coating composition" is for forming a coating film having an uneven pattern by spray coating. This coating composition contains at least a base agent, a curing agent, and a fatty acid amide as coating film components. Furthermore, in this coating composition, the content of fatty acid amide in 100 parts by mass of coating film components is 2.5 to 15 parts by mass.

The present inventors have discovered that when coating an object by granulating a paint composition using a spray gun, even after the granular paint composition reaches the surface of the object, the "granular shape" remains to some extent. If this could be maintained, we thought that it would be possible to form a coating film with an uneven pattern in a single spray coating.

The present inventors proceeded with studies based on the above idea. In the course of the study, the present inventors attempted to prepare a coating composition containing "fatty acid amide", which is conventionally known as a thixotropic modifier, in a much larger amount than the usual amount for adjusting thixotropic properties. Thought. Then, when the coating composition is spray-painted onto the surface of the object to be coated, the action of the fatty acid amide suppresses the flow of the coating composition even after the granular coating composition reaches the surface of the object to be coated. I thought that the ``granular shape'' would be maintained to some extent.
(For reference, when fatty acid amide is used to adjust the thixotropic properties of paints, which is its usual use, the amount is usually about 1% by mass in the coating film components (non-volatile components).)

Based on the above idea, the present inventors specifically:
(1) preparing a coating composition containing at least a base agent, a curing agent, and a fatty acid amide as coating film components, the content of fatty acid amide in 100 parts by mass of the coating film component is 2.5 to 15 parts by mass;
(2) The paint composition was spray-painted onto the surface of the object to be coated using a spray gun.
By doing so, the present inventors succeeded in forming a coating film (cured film) having an uneven pattern by just one spray coating.

Additional findings of the present inventors will be described for reference.

(1) Since the content of fatty acid amide in 100 parts by mass of the coating film component is 2.5 to 15 parts by mass, it is easy to form relatively large irregularities. Even if the content of fatty acid amide in 100 parts by mass of the coating film component is less than 2.5 parts by mass, an uneven pattern can be formed in some cases, but the size of the unevenness tends to be small.

(2) In the studies conducted by the present inventors, it is possible to prepare a coating composition that can form an uneven pattern with a single spray coating even by using a relatively large amount of a known thixotropic agent other than fatty acid amide. . However, such coating compositions tend to have large variations in viscosity depending on the amount of solvent. This tendency is an undesirable property in spray painting, where painters often dilute the paint with organic solvents (thinners) immediately before application. By preparing a coating composition using a fatty acid amide, viscosity fluctuations due to dilution can be moderated.

Hereinafter, first, the constituent components and physical properties of the coating composition used in the method for producing a coated article of this embodiment will be specifically explained. After that, the specific method and conditions for spray painting using a spray gun will be explained.

(base agent)
As the base agent contained in the coating composition as a coating component, those known in the field of coatings can be used as appropriate. The base material is typically a resin. There are no particular restrictions on the resin. Examples include (meth)acrylic resins, urethane resins, epoxy resins, polyester resins, and alkyd resins.

As one aspect, it is preferable that the main agent contains a (meth)acrylic resin.
(Meth)acrylic resin is typically a copolymer.
In this specification, "(meth)acrylic resin" refers to structural units in which typically 50% by mass or more, preferably 75% by mass or more of all structural units are derived from (meth)acrylic monomers. Refers to a certain resin. In other words, in addition to structural units derived from (meth)acrylic monomers, (meth)acrylic resins may contain structural units derived from monomers other than (meth)acrylic monomers (for example, structural units derived from styrene monomers). units, etc.).

The (meth)acrylic resin preferably contains a structural unit having a hydroxy group in a side chain for reaction with a curing agent. Examples of this structural unit include structural units derived from hydroxyalkyl (meth)acrylates such as 2-hydroxyethyl (meth)acrylate, hydroxypropyl (meth)acrylate, and hydroxybutyl (meth)acrylate.
When the (meth)acrylic resin contains a structural unit having a hydroxyl group in the side chain, the (meth)acrylic resin may contain only one type of this structural unit, or may contain two or more types of this structural unit.
The amount of this structural unit is, for example, 1 to 50% by weight, more preferably 2 to 30% by weight, and still more preferably 3 to 25% by weight, based on the entire (meth)acrylic resin.

The (meth)acrylic resin may include a structural unit having an amino group in a side chain. The amino group here is preferably a tertiary amino group. Examples of this structural unit include dimethylaminoethyl (meth)acrylate, dimethylaminopropyl (meth)acrylate, dimethylaminobutyl (meth)acrylate, diethylaminoethyl (meth)acrylate, diethylaminopropyl (meth)acrylate, and diethylaminobutyl (meth)acrylate. ) acrylate and other dialkylaminoalkyl (meth)acrylates. In addition, dialkylamino acids such as dimethylaminomethyl (meth)acrylamide, diethylaminomethyl (meth)acrylamide, dimethylaminoethyl (meth)acrylamide, diethylaminoethyl (meth)acrylamide, dimethylaminopropyl (meth)acrylamide, diethylaminopropyl (meth)acrylamide, etc. Structural units derived from alkyl (meth)acrylamide can also be mentioned.
When the (meth)acrylic resin contains a (meth)acrylate structural unit having an amino group in the side chain, the (meth)acrylic resin may contain only one type of this structural unit, or may contain two or more types of this structural unit. good.
The amount of this structural unit is, for example, 1 to 50% by weight, more preferably 2 to 30% by weight, and still more preferably 3 to 25% by weight, based on the entire (meth)acrylic resin.

The (meth)acrylic resin is preferably a monomer represented by the general formula CH ₂ =CR-COO-R' (R is a hydrogen atom or a methyl group, R' is an alkyl group, or a monocyclic or polycyclic cycloalkyl group). group, aryl group, or aralkyl group).
This structural unit includes methyl (meth)acrylate, ethyl (meth)acrylate, n-butyl (meth)acrylate, isobutyl (meth)acrylate, tert-butyl (meth)acrylate, 2-ethylhexyl (meth)acrylate, isodecyl ( Examples include structural units derived from monomers such as meth)acrylate, n-lauryl(meth)acrylate, n-stearyl(meth)acrylate, phenyl(meth)acrylate, and benzyl(meth)acrylate.
When the (meth)acrylic resin contains this structural unit, the (meth)acrylic resin may contain only one type of this structural unit, or may contain two or more types of this structural unit.
The amount of this structural unit is, for example, 1 to 90% by weight, more preferably 10 to 85% by weight, and even more preferably 20 to 80% by weight, based on the entire (meth)acrylic resin.

The (meth)acrylic resin may include a structural unit having an amide group.
Examples of this structural unit include structural units derived from monomers such as (meth)acrylamide, more specifically, (meth)acrylamide and N,N-dialkyl (meth)acrylamide. Among these, N,N-dialkyl (meth)acrylamide is preferred.
Examples of the structural unit having an amide group include structural units derived from monomers such as dimethyl (meth)acrylamide and diethyl (meth)acrylamide.
When the (meth)acrylic resin contains this structural unit, the (meth)acrylic resin may contain only one type of this structural unit, or may contain two or more types of this structural unit.

The (meth)acrylic resin preferably contains a structural unit derived from acrylic acid or methacrylic acid.
When the (meth)acrylic resin contains this structural unit, the (meth)acrylic resin may contain only one type of this structural unit, or may contain two or more types of this structural unit.
The amount of this structural unit is, for example, 0.1 to 30% by mass, more preferably 0.2 to 20% by mass, and even more preferably 0.2 to 10% by mass, based on the entire (meth)acrylic resin. .

The (meth)acrylic resin may include a structural unit derived from a monomer other than the (meth)acrylic monomer that is copolymerizable with the (meth)acrylic monomer. For example, it may contain structural units derived from styrene monomers such as styrene and α-methylstyrene, vinyl monomers such as vinyl acetate and vinyl propionate, and unsaturated carboxylic acid monomers such as itaconic acid, maleic acid, and fumaric acid. good.
When the (meth)acrylic resin contains this structural unit, the (meth)acrylic resin may contain only one type of this structural unit, or may contain two or more types of this structural unit.
From the viewpoints of flexibility, compatibility with other components, solvent solubility, etc., the amount of structural units derived from monomers that are not (meth)acrylic monomers in the (meth)acrylic resin is preferably The amount is 0 to 50% by weight, more preferably 3 to 30% by weight based on the total resin.

As another point of view, it is preferable that the main agent contains a resin having a branched structure and/or a crosslinked structure. It is thought that because the base material contains such a resin, the degree of freedom of movement of the base material itself is restricted. It is thought that the unevenness will be less likely to collapse between painting and curing, making it easier to control the uneven pattern. Further, even when a large amount of organic solvent is used, it tends to be easy to obtain a sufficiently uneven pattern.

As an example, when the main resin contains a (meth)acrylic resin, a resin having a crosslinked structure can be obtained by using a poly(meth)acrylate monomer in the synthesis of the (meth)acrylic resin.
Examples of the poly(meth)acrylate monomer include di- to hexafunctional poly(meth)acrylate monomers. Among these, di(meth)acrylate monomers are preferred from the viewpoint of suppressing gelation of the main ingredient.

Examples of di(meth)acrylate monomers include lyethylene glycol di(meth)acrylate, tetraethylene glycol di(meth)acrylate, polyethylene glycol di(meth)acrylate, tripropylene glycol di(meth)acrylate, and polypropylene glycol di(meth)acrylate. Acrylate, 1,4-butanediol di(meth)acrylate, 1,6-hexanediol di(meth)acrylate, 1,9-nonanediol di(meth)acrylate, neopentyl glycol di(meth)acrylate, dimethylol-triacrylate Examples include cyclodecane di(meth)acrylate, PO adduct di(meth)acrylate of bisphenol A, neopentyl hydroxypivalate glycol di(meth)acrylate, polytetramethylene glycol di(meth)acrylate, and the like.
Di(meth)acrylate monomers are sold, for example, by Kyoeisha Kagaku Co., Ltd. under the trade name "Light Acrylate."

As another example, when the main resin contains a (meth)acrylic resin, a resin having a branched structure can be obtained by using a macromonomer during synthesis of the (meth)acrylic resin.
Naturally, a resin having a branched structure may be obtained by graft polymerization using a chain resin as a raw material.

When the resin includes a branched structure and/or a crosslinked structure, the amount thereof in the entire resin is determined from the viewpoint of suppressing excessive changes in viscosity while sufficiently obtaining the effects of including the branched structure and/or crosslinked structure, for example. The amount is 0.1 to 5% by weight, more preferably 0.1 to 3% by weight, and even more preferably 0.1 to 1% by weight. This amount can be estimated from the amount of monomer blended during resin synthesis.

The hydroxyl value of the main ingredient is preferably 10 to 200 mgKOH/g, more preferably 15 to 150 mgKOH/g, even more preferably 20 to 120 mgKOH/g. By having a hydroxyl value of 10 mgKOH/g or more, the curing speed can be made appropriate, especially when the hydroxyl group in the base resin reacts with the curing agent. Further, by having a hydroxyl value of 200 mgKOH/g or less, excessive curing can be suppressed and it is easy to obtain a suitably flexible coating film. In addition, unintended hardening is suppressed, making it easier to extend pot life.
The hydroxyl value is determined by the method specified in ``7.1 Neutralization titration method'' of JIS K 0070 ``Testing methods for acid value, saponification value, ester value, iodine value, hydroxyl value, and unsaponifiable substances of chemical products.'' Required according to. In addition, when calculating the hydroxyl value, the value of the acid value is also required, but the value of the acid value is also determined according to the method specified in "3.1 Neutralization titration method" of the same JIS standard.

When the main ingredient contains a resin, the number average molecular weight (Mn) of the resin is preferably 1,000 to 50,000, more preferably 2,000 to 30,000, and still more preferably 3,000 to 20,000.
When the main ingredient contains a resin, the weight average molecular weight (Mw) of the resin is preferably 2,000 to 100,000, more preferably 4,000 to 60,000, and still more preferably 6,000 to 40,000.
When the base material contains a resin, the polydispersity (Mw/Mn) of the resin is preferably 1 to 6, more preferably 1 to 5, and still more preferably 1 to 4.
The number average molecular weight and weight average molecular weight can be measured as standard polystyrene equivalent values by gel permeation chromatography (GPC).

When the main ingredient contains a resin, the glass transition temperature of the resin is preferably -20 to 100°C, more preferably -5 to 80°C. By setting it as this range, the spreadability and scratch resistance of the cured film obtained by curing the composition can be further improved.
Glass transition temperature can be determined by various methods. For example, it can be determined based on the following formula (known as Fox's formula).
1/Tg=(W ₁ /Tg ₁ )+(W ₂ /Tg ₂ )+(W ₃ /Tg ₃ )+...+(W _n /Tg _n )

In the formula, Tg is the glass transition temperature (K) of the resin, W ₁ , W ₂ , W ₃ ...W _n is the mass fraction of each monomer, Tg ₁ , Tg ₂ , Tg ₃ ...Tg _n represents the glass transition temperature (K) of a homopolymer made of monomers corresponding to the mass fraction of each monomer. For monomers whose glass transition temperatures are unknown, such as special monomers and polyfunctional monomers, the glass transition temperature can be determined using only monomers whose glass transition temperatures are known.

The method for producing the main ingredient is not particularly limited. When the main ingredient contains a (meth)acrylic resin, the (meth)acrylic resin can be obtained by a known polymerization method (for example, a radical polymerization method). For specific polymerization methods, please refer to the Examples below, for example.

A commercially available product can also be used as the main ingredient. For example, commercially available isocyanate-curing acrylic resins, normal temperature/forced drying (one-liquid) acrylic resins, melamine baking acrylic resins, moisture-curing silicone acrylic resins, and the like may be used. Examples of the base resin that fall under these categories include (meth)acrylic resin sold by DIC Corporation under the trade name "Acridic".

The coating composition may contain only one type of base agent, or may contain two or more types of base ingredients.
The content of the base agent in the coating composition is, for example, 10 to 80% by mass, preferably 30 to 70% by mass, and more preferably 40 to 60% by mass, based on the entire coating film component (i.e., the entire nonvolatile content). .

(hardening agent)
The curing agent contained in the coating composition as a coating component may be any curing agent as long as it is capable of curing the coating composition by reacting with the base agent (typically a resin) by heating or the like. Something can happen.

Preferred examples of the curing agent include isocyanate compounds (including blocked isocyanate compounds). Isocyanate compounds are particularly preferably used when the resin has a hydroxyl group. In terms of storage stability, blocked isocyanate compounds are more preferred.
The isocyanate compound is preferably a polyfunctional isocyanate. The polyfunctional isocyanate is preferably 2-6 functional (ie, has 2-6 reactive isocyanate groups per molecule), more preferably 2-4 functional.

Isocyanate compounds include aliphatic diisocyanates such as lysine diisocyanate, hexamethylene diisocyanate and trimethylhexane diisocyanate, hydrogenated xylylene diisocyanate, isophorone diisocyanate, methylcyclohexane-2,4-(or 2,6)-diisocyanate, 4,4' Cycloaliphatic diisocyanates such as -methylenebis(cyclohexyl isocyanate) and 1,3-(isocyanatomethyl)cyclohexane, and trifunctional or higher functional isocyanates such as lysine triisocyanate can be mentioned.
Isocyanurate and biuret type adducts, which are multimers of isocyanate compounds, as well as isocyanate compounds added to polyhydric alcohols or low molecular weight polyester resins, etc. can also be used as the isocyanate compound.

Incidentally, as isocyanate compounds, biuret type, isocyanurate type, adduct type, allophanate type, etc. are known. Any of these can be used in this embodiment. Among these, it is preferable to use an isocyanurate type isocyanate compound, that is, a polyfunctional isocyanate having a cyclic skeleton of isocyanuric acid.

The isocyanate compound may be a so-called blocked isocyanate. In other words, part or all of the isocyanate groups of the isocyanate compound may be in the form of blocked isocyanate groups blocked with a protecting group. For example, isocyanate groups are blocked by active hydrogen compounds such as alcohols, phenols, lactams, oximes, and active methylenes to form blocked isocyanate groups.

The amount of isocyanate groups that an isocyanate compound has can be expressed as a mass ratio of isocyanate groups (-NCO) to the entire isocyanate compound. The mass ratio (NCO%) of isocyanate groups to the total isocyanate compound is preferably 5 to 50%, more preferably 5 to 30%, and even more preferably 10 to 25%.

Commercially available isocyanate compounds include, for example, the Duranate (product name) series manufactured by Asahi Kasei Corporation, the Takenate (product name) series manufactured by Mitsui Chemicals, and the Desmodur (product name) series manufactured by Sumika Bayer Urethane Co., Ltd. etc. can be used.

Examples of curing agents other than isocyanate compounds include melamine compounds and compounds containing hydrolyzable silyl groups and epoxy groups.

Examples of melamine compounds include known or commercially available melamine resins. More specifically, publicly known or commercially available butylated melamine resins, methylated melamine resins, and the like can be mentioned. Commercial products of melamine resin include Amidia (registered trademark) L-117-60, L-109-65, J-820-60, L-125-60, L-127-60, and L- manufactured by DIC Corporation. Examples include 150-60, L-166-60B, and L-105-60.

Compounds containing a hydrolyzable silyl group and an epoxy group are preferably used especially when the base resin (resin) contains an amino group.
Compounds containing hydrolyzable silyl groups and epoxy groups include γ-glycidoxypropyltrimethoxysilane, γ-glycidoxypropyltriethoxysilane, γ-glycidoxypropylmethyldiethoxysilane, γ-glycid Examples include xypropyltriisopropenyloxysilane and γ-glycidoxypropyltriiminooxysilane. There are also hydrolyzed condensates of these compounds and tetramethoxysilane and tetraethoxysilane.
In addition, compounds such as γ-isocyanatepropyltriisopropenyloxysilane and γ-isocyanatepropyltrimethoxysilane (compounds that have both an isocyanate group and a hydrolyzable silyl group) and glycidol (compounds that have both an epoxy group and a hydroxyl group) and addition reaction products of γ-aminopropyltrimethoxysilane (a compound having both an amino group and a hydrolyzable silyl group) and a diepoxy compound.
Furthermore, a (meth)acrylic copolymer consisting of a vinyl monomer containing an epoxy group, such as glycidyl methacrylate, and a vinyl monomer containing a hydrolyzable silyl group, such as 3-methacryloxypropyltrimethoxysilane. There are also high molecular weight compounds such as
Compounds containing hydrolyzable silyl groups and epoxy groups include Acridic A-9585, Acridic A-9585-BA (a product in which only the solvent of A-9585 is changed), and Acridic FZ-521 manufactured by DIC Corporation. Commercially available products such as Acridic FZ-523 and the like can also be mentioned.

The coating composition may contain only one type of curing agent, or may contain two or more types of curing agent.
The content of the curing agent in the coating composition is preferably 5 to 55% by mass, more preferably 10 to 50% by mass, and even more preferably 15 to 45% by mass based on the entire coating film component (that is, the entire nonvolatile content). %.

(fatty acid amide)
Regarding fatty acid amide, it is thought that a network structure is formed in the coating composition due to the polarity of the amide group in the fatty acid amide. In this embodiment, in particular, since the coating composition contains a relatively large amount of fatty acid amide, a relatively strong network structure is formed, and flow is sufficiently suppressed when no shear force is applied to the coating composition. it is conceivable that. As a result, even after the granular paint composition reaches the surface of the object to be coated, the "granular shape" is likely to be maintained, making it possible to form a coating film with an uneven pattern in a single spray application. It will be done.

Fatty acid amides themselves are known in the paint art as thixotropic agents. In this embodiment, a known or commercially available fatty acid amide can be used as a thixotropic agent.
The fatty acid amide preferably has two or more amide bonds in one molecule. The fatty acid amide may be a low-molecular compound, an oligomer, or a polymer.

Fatty acid amide can typically be obtained by a condensation reaction between a fatty acid (for example, an aliphatic monocarboxylic acid having 2 to 22 carbon atoms) and an amine. If a diamine is used as the amine and the equivalent ratio of fatty acids is appropriately adjusted, a diamide compound, which is a compound containing two amide bonds in one molecule, can be obtained.
As a preferred example, by using hydrogenated castor oil fatty acid (main component: 12-hydroxystearic acid) as the fatty acid and a diamine such as ethylenediamine, 1,4-diaminobutane, hexamethylenediamine or xylylenediamine as the amine, A fatty acid amide (diamide compound) suitable for addition to paints can be obtained. That is, the fatty acid amide preferably contains a structure derived from 12-hydroxystearic acid.
When producing fatty acid amide, dicarboxylic acids such as azelaic acid and sebacic acid may be used. It is thought that when a dicarboxylic acid and a diamine are subjected to a condensation reaction, a fatty acid amide, which is an oligomer or a polymer, is obtained.

A preferred viewpoint for selecting a fatty acid amide is the peak top temperature of the melting peak when the fatty acid amide (nonvolatile content) is subjected to DSC measurement (differential scanning calorimetry).
Specifically, a fatty acid amide whose melting peak top temperature is preferably 130° C. or higher, more preferably 130 to 150° C. when the fatty acid amide (nonvolatile content) is measured by DSC is selected. In addition, when two or more melting peaks are recognized in DSC measurement, the peak top temperature of the peak with the lowest temperature is adopted.
By using a fatty acid amide whose melting peak temperature is 130° C. or higher, it is possible to improve the adhesion, water resistance, etc. of the final coating film. This is particularly important when relatively large amounts of fatty acid amide are used.

Specific examples of fatty acid amides include the following.
Monoamides: Saturated fatty acid monoamides such as lauric acid amide, palmitic acid amide, stearic acid amide, behenic acid amide, hydroxystearic acid amide, etc., oleic acid amide, erucic acid amide, ricinoleic acid amide, etc.
Substituted amides: N-lauryl lauryl amide, N-palmityl palmitic acid mimide, N-stearyl stearamide, N-oleyl oleic acid amide, N-stearyl oleic acid amide, N-oleyl stearic acid amide N-stearyl Erucic acid amide, N-oleyl palmitic acid amide, N-12 hydroxystearyl stearic acid amide, N-12 hydroxystearyl oleic acid amide, etc.
Methylolamides: Methylolstearamide, methylolbehenic acid amide.
Bisamides: methylene bisstearamide, methylene bislauric acid amide, methylene bishydroxystearic acid amide, methylene bisolenic acid amide, ethylene biscaprylic acid amide, ethylene bislauric acid amide, ethylene bis stearic acid amide, ethylene bis isostearic acid amide, ethylenebishydroxystearamide, ethylenebisbehenamide, hexamethylenebisbehenamide, hexamethylenebisstearamide, hexamethylenebishydroxystearamide, butylenebishydroxystearamide, N,N'-di Saturated fatty acid bisamides such as stearyl adipic acid amide, N,N'-distearyl sebacic acid amide, ethylene bis oleic acid amide, ethylene bis erucic acid amide, hexamethylene bis oleic acid amide, N,N'-dioleyl adipic acid amide (melting point 119°C), unsaturated fatty acid bisamides such as N,N'-dioleylsebacic acid amide (melting point 115°C), m-xylylene bisstearamide (melting point 123°C), N,N'-dioleylsebacin Aromatic bisamides such as acid amides, fatty acid ester amides such as ethanolamine distearate.

Commercial products of fatty acid amide include Disparon 6900-20X, Disparon 6900-10X, Disparon A603-20X, Disparon A603-10X, Disparon A670-20M, Disparon A671-EZ, Disparon F-9050, manufactured by Kusumoto Kasei Co., Ltd. Disparon PFA-220, Disparon PFA-231, Disparon PFA-131, Disparon 6810-20X, Disparon 6850-20X, Disparon 6820-20M, Disparon 6820-10M, Disparon FS-6010, Disparon 3900EF, Disparon 6500, Disparon 6300, Disparon 6650, Disparon 6700, etc.

Furthermore, fatty acid amides from the "Turen" series sold by Kyoeisha Kagaku Co., Ltd. as an anti-sagging agent for paints can also be used. Specifically, examples include Talen 7200-20, Talen 8200-20, Talen 8300-20, Talen 8700-20, Talen BA-600, Talen M-1020XFS, Talen M-1021B, Talen VA-750B, etc. .

In the coating composition, the fatty acid amide is preferably dissolved in the organic solvent described below, or even if not completely dissolved in the organic solvent, it is preferably dispersed in the organic solvent as particles with a particle size of 10 μm or less. This prevents "clogging" during spray painting. In other words, in this embodiment, the fatty acid amide does not exist as an "aggregate" as described in Patent Document 2.

The coating composition may contain only one fatty acid amide, or may contain two or more fatty acid amides.
The content of fatty acid amide in 100 parts by mass of coating film components (ie, non-volatile components) may be 2.5 to 15 parts by mass as described above. In one embodiment, this amount is preferably 2.75 to 10 parts by weight, more preferably 3 to 8 parts by weight. In another embodiment, this amount is preferably from 2.55 to 10 parts by weight, more preferably from 2.5 to 8 parts by weight.
By adjusting this amount, the size of the uneven pattern can be adjusted. Furthermore, by not using too much fatty acid amide, it is possible to improve the adhesion and water resistance of the final coating film. Furthermore, since the amount of fatty acid amide is not too large, painting workability (spray workability) can be improved.
Just to be clear, the content of fatty acid amide is the content of fatty acid amide "only" (active ingredient only) (commercially available fatty acid amide contains solvent, etc., so it is not 100% active ingredient). There are some things that aren't there).

(pigment)
The coating composition may include a pigment as a coating component. A coating film with a desired color can be obtained by using pigments. From the viewpoint of suppressing discoloration in the baking step described later, it is preferable that the pigment contains an inorganic pigment.
The pigment can include, for example, known colored pigments such as organic pigments and inorganic pigments.

Specific pigments include white pigments such as titanium dioxide (titanium white), zinc white, lead white, basic lead sulfate, lead sulfate, lithopone, zinc sulfide, and antimony white; carbon black, acetylene black, lamp black, and graphite. Black pigments such as , iron black (black iron oxide), aniline black; yellow pigments such as naphthol yellow S, Hansa yellow, pigment yellow L, benzidine yellow, permanent yellow, yellow iron (yellow iron oxide); chrome orange, chrome vermilion , orange pigments such as permanent orange; brown pigments such as iron oxide and amber; red pigments such as red iron oxide (red iron oxide), red lead, permanent red, quinacridone red pigments, and diketopyrrolopyrrole red pigments; cobalt purple, Examples include purple pigments such as fast violet and methyl violet lake; blue pigments such as ultramarine blue, navy blue, cobalt blue, phthalocyanine blue, and indigo; and green pigments such as chrome green, pigment green B, and phthalocyanine green. Of course, usable pigments are not limited to these.

The pigment may include an extender pigment.
Extender pigments include, for example, barita powder, barium sulfate, barium carbonate, calcium carbonate, gypsum, clay, silica, white carbon, diatomaceous earth, talc, magnesium carbonate, hydrated magnesium silicate, alumina white, gloss white, mica powder, etc. be able to.

When the coating composition contains a pigment, it may contain only one pigment, or it may contain two or more pigments.
When the coating composition contains a pigment, the amount thereof is preferably 1 to 70 parts by mass, more preferably 5 to 60 parts by mass, based on 100 parts by mass of coating film components (i.e., non-volatile components), although it depends on the color of the pigment. Department.

(Organic solvent)
The coating composition may contain an organic solvent as a volatile component. Organic solvents make the coating composition easier to apply for spray coating. The organic solvent that can be used is not particularly limited. One or more solvents known in the paint art can be used. Specifically, organic solvents include alcohol solvents, ketone solvents, ester solvents, ether solvents, glycol ether solvents, aliphatic hydrocarbon solvents (chain, branched, or cyclic), and carbonate solvents. One or more of these can be used.

Examples of alcoholic solvents include methanol, ethanol, isopropanol, 1-butanol, tertiary butanol, isobutanol, diacetone alcohol, 3-methoxy-3-methyl-1-butanol, and the like.
Examples of the ketone solvent include acetone, methyl ethyl ketone, diethyl ketone, methyl isobutyl ketone, cyclopentanone, cyclohexanone, diisobutyl ketone, and the like.
Examples of the ester solvent include ethyl acetate, methyl acetate, butyl acetate, methoxybutyl acetate, cellosolve acetate, amyl acetate, n-propyl acetate, isopropyl acetate, methyl lactate, ethyl lactate, butyl lactate, and the like.
Examples of the ether solvent include dibutyl ether, tetrahydrofuran, and dioxane.
Examples of glycol ether solvents include ethylene glycol monomethyl ether, diethylene glycol monomethyl ether, diethylene glycol monoethyl ether, diethylene glycol diethyl ether, diethylene glycol dibutyl ether, butyl cellosolve (ethylene glycol monobutyl ether), and the like.
Examples of the aliphatic hydrocarbon solvent include normal pentane, cyclopentane, methylcyclopentane, n-hexane, isohexane, normal heptane, normal octane, cyclohexane, methylcyclohexane, and ethylcyclohexane.
Examples of carbonate solvents include propylene carbonate, ethylene carbonate, dimethyl carbonate, diethyl carbonate, and methyl ethyl carbonate.
Mention may also be made of the various petroleum solvents known in the coatings field.

Part or all of the organic solvent is preferably a low boiling point organic solvent having a boiling point of 150°C or less (more specifically, 50 to 150°C).
Specifically, the proportion of the low-boiling organic solvent in the organic solvent is preferably 25% by mass or more, more preferably 40% by mass or more, still more preferably 50% by mass or more, particularly preferably 60% by mass or more. All of the organic solvents may be low boiling point organic solvents.
Since part or all of the organic solvent is a low boiling point organic solvent, the granular coating composition sprayed from the spray gun and reaching the surface of the object to be coated tends to dry quickly while maintaining its shape. Therefore, it is thought that it becomes easier to form a desired uneven pattern, and it becomes easier to reduce variations in the size of the unevenness due to changes in coating conditions.

When the coating composition contains an organic solvent, the amount used is usually such that the proportion of the coating film components (nonvolatile component concentration) in the entire coating composition is 20 to 80% by mass.
The concentration and viscosity of the coating composition may be adjusted by adding an organic solvent (thinner) to the coating composition immediately before spray painting.

(Other ingredients)
The coating composition can contain various optional components in addition to those mentioned above. For example, antifoaming agents, anti-wrinkle agents, curing accelerators (curing catalysts, etc.), surfactants, ultraviolet absorbers, dispersants, light stabilizers, antioxidants, antistatic agents, light stabilizers, etc. , one or more may be included. These are usually classified as "coating film components."
Incidentally, as mentioned above, the coating composition of this embodiment can form an uneven pattern without using particles for forming an uneven pattern (for example, organic particles such as polyethylene particles) due to the presence of a relatively large amount of fatty acid amide. Formable. That is, the coating composition preferably does not contain organic particles such as polyethylene particles, or even if it does, the amount is 1% by mass or less based on the total coating film components.

(Viscosity of paint composition)
By having an appropriate viscosity of the coating composition, it is possible to prevent clogging when using a general-purpose spray gun and to adjust the size of the uneven pattern. The viscosity can be adjusted, for example, by adjusting the type and amount of fatty acid amide, or by adjusting the type and amount of organic solvent.
Specifically, the viscosity η _{6 rpm} of the coating composition measured using a B-type viscometer at 25° C. and a rotation speed of 6 rpm is preferably 0.2 to 50 Pa·s, more preferably 1.0. ~20 Pa·s, more preferably 5.0~15 Pa·s.
In addition, the viscosity η _{60 rpm} of the coating composition measured using a B-type viscometer at 25° C. and 60 rpm is preferably 0.03 to 25 Pa·s, more preferably 0.10 to 10 Pa·s. s, more preferably 0.50 to 5 Pa·s.

(About preparation of paint composition)
The method and timing of preparing the coating composition are not particularly limited as long as a coating film having an uneven pattern can be formed by spray coating.
As an example, a coating composition can be prepared by separately storing the base agent, curing agent, fatty acid amide, organic solvent, etc. in separate containers, and mixing these immediately before spray coating.
As another example, the paint composition may be prepared by separately storing the mixture of the base agent and fatty acid amide, the curing agent, the organic solvent, etc. in separate containers, and mixing these immediately before spray painting. .
As yet another example, a paint composition is prepared by preparing a mixture in advance that includes a base agent, a curing agent, and a fatty acid amide but does not contain or contains a small amount of an organic solvent, and dilutes it with an organic solvent immediately before spray painting. You may.

In preparing the coating composition, various apparatuses commonly used in the preparation of coating compositions, such as a paint shaker, may be used for the purpose of increasing the dispersibility and uniformity of each component.

(Specific conditions for spray painting, etc.)
In this embodiment, the coating composition described above is spray-coated onto the surface of an object to be coated using a spray gun to produce a coated object having a coating film having an uneven pattern. Spray guns are available, for example, from Anest Iwata Co., Ltd.
Spray painting is usually performed at room temperature (in an environment of about 10 to 40 degrees Celsius).

The specific conditions for spray painting may be set as appropriate depending on the size of the desired uneven pattern, but in particular, as conditions that facilitate the formation of an uneven pattern of an appropriate size, the air pressure during spray painting is as follows: For example, it is 0.05 to 1.0 MPa, preferably 0.15 to 0.35 MPa. Further, the distance between the object to be coated and the discharge part of the spray gun is, for example, 10 to 100 cm, preferably 15 to 50 cm, and more preferably 20 to 30 cm.
Ejecting the paint composition from the spray gun with appropriate pressure and appropriately adjusting the distance between the object to be coated and the discharge part of the spray gun are important in order to form a coating film with a highly designed uneven pattern. is important.

As another aspect, the amount of paint composition ejected from the spray gun is preferably 50 to 1000 mL/min, more preferably 100 to 800 mL/min, and even more preferably 150 to 600 mL/min. Painting efficiency can be increased by appropriately increasing the amount of spray per unit time. It is thought that by not ejecting too much amount per unit time, "overlapping" of the granular coating compositions is suppressed, making it easier to obtain an uneven pattern with high design quality.

A baking process may be performed after spray painting. The temperature and time of the baking process may be set appropriately. As an example, the temperature and time are about 60 to 180° C. and about 1 to 120 minutes. The baking step can be performed by a known method using equipment known in the painting field.

The size of the uneven pattern can be changed as appropriate by adjusting the composition of the coating composition and the spray coating conditions. As just one example, the size of the uneven pattern is approximately 0.1 to 3 mm. The "size of the uneven pattern" herein refers to the value obtained by observing the surface of the coating film using a stereomicroscope, measuring the sizes of 100 uneven patterns (dots), and calculating the arithmetic average of the measurements.

The object to be coated is not particularly limited. A preferable example is one having a metal base. Specifically, light and heavy electrical equipment, agricultural machinery, steel furniture, machine tools, construction machinery (for example, bulldozers, scrapers, hydraulic excavators, excavators, transportation machines (trucks, trailers, etc.), cranes and cargo handling machines) , foundation construction machines (diesel hammers, hydraulic hammers, etc.), tunnel construction machines (boring machines, etc.), road rollers, etc.), road materials, housing-related materials, home appliances, and automobile products.
In addition, those having a plastic base can also be mentioned. For example, the housings of electronic devices such as mobile phones, smartphones, tablet terminals, personal computers, digital cameras, and game consoles, the housings of home appliances such as televisions, refrigerators, washing machines, and air conditioners, and the housings of various vehicles such as automobiles and railway cars. Examples include interior materials.

Although the embodiments of the present invention have been described above, these are merely examples of the present invention, and various configurations other than those described above can be adopted. Furthermore, the present invention is not limited to the above-described embodiments, and the present invention includes modifications, improvements, etc. within a range that can achieve the purpose of the present invention.
Below, examples of reference forms will be added.
1.
A coating composition containing at least a base agent, a curing agent, and a fatty acid amide as a coating film component, and a content of the fatty acid amide in 100 parts by mass of the coating film component is 2.5 to 15 parts by mass,
A method for producing a coated article, which includes spray painting the surface of the coated article using a spray gun to produce a coated article having a coating film having an uneven pattern.
2.
1. The method for manufacturing a coated article according to
The spray painting is a method for manufacturing a coated object, in which the spray painting is performed under the following conditions.
[conditions]
・Blowing air pressure: 0.05-1.0MPa
・Distance between the object to be coated and the spray gun discharge part: 10 to 100 cm
3.
1. or 2. The method for manufacturing a coated article according to
The coating composition further includes an organic solvent as a volatile component.
4.
3. The method for manufacturing a coated article according to
The method for producing a coated article, wherein the organic solvent includes a low boiling point organic solvent having a boiling point of 150°C or less.
5.
4. The method for manufacturing a coated article according to
A method for producing a coated article, wherein the proportion of the low boiling point organic solvent in the organic solvent is 25% by mass or more.
6.
3. ~5. A method for producing a coated article according to any one of
A method for producing a coated article, wherein the fatty acid amide is dissolved in the organic solvent or dispersed in the organic solvent as particles with a particle size of 10 μm or less.
7.
1. ~6. A method for producing a coated article according to any one of
A method for producing a coated article, wherein the coating composition has a viscosity η _{6 rpm} of 0.2 to 50 Pa·s as measured using a B-type viscometer at 25° C. and a rotation speed of 6 rpm .
8.
1. ~7. A method for producing a coated article according to any one of
A method for producing a coated article, wherein the coating composition has a viscosity η _{60 rpm} of 0.03 to 25 Pa·s as measured using a B-type viscometer at 25° C. and a rotation speed of 60 rpm .
9.
1. ~8. A method for producing a coated article according to any one of
The coating composition further includes a pigment as a coating film component.
10.
1. ~9. A method for producing a coated article according to any one of
The method for producing a coated article, wherein the main agent includes a (meth)acrylic resin.
11.
1. ~10. A method for producing a coated article according to any one of
A method for producing a coated article, wherein the main agent includes a polymer having a branched structure and/or a crosslinked structure.
12.
A coating composition for forming a coating film having an uneven pattern by spray coating,
Coating film components include at least a base agent, a curing agent, and a fatty acid amide,
A coating composition in which the content of the fatty acid amide in 100 parts by mass of the coating film component is 2.5 to 15 parts by mass.
13.
12. The coating composition according to
Furthermore, a coating composition containing an organic solvent as a volatile component.
14.
13. The coating composition according to
The organic solvent is a coating composition containing a low boiling point organic solvent having a boiling point of 150° C. or lower.
15.
14. The coating composition according to
A coating composition wherein the proportion of the low boiling point organic solvent in the organic solvent is 25% by mass or more.
16.
13. ~15. The coating composition according to any one of
A coating composition in which the fatty acid amide is dissolved in the organic solvent or dispersed in the organic solvent as particles having a particle size of 10 μm or less.
17.
12. ~16. The coating composition according to any one of
A coating composition in which η _{6 rpm} is 0.2 to 50 Pa·s.
18.
12. ~17. The coating composition according to any one of
A coating composition in which η _{60 rpm} is 0.03 to 25 Pa·s.
19.
12. ~18. The coating composition according to any one of
A coating composition further containing a pigment as a coating component.
20.
12. ~19. The coating composition according to any one of
The main agent is a coating composition containing a (meth)acrylic resin.
21.
12. ~20. The coating composition according to any one of
A coating composition in which the main agent includes a polymer having a branched structure and/or a crosslinked structure.

Embodiments of the present invention will be described in detail while showing examples and the like. It should be noted that the present invention is not limited only to the embodiments.
<Preparation of main ingredient>
(Synthesis of resin (A-1))
100 parts by mass of butyl acetate was charged into a flask equipped with a stirrer, a thermometer, a reflux condenser, and a nitrogen gas introduction tube, and the temperature was raised to reflux temperature.
Next, while stirring the butyl acetate in the flask with a stirrer, 40 parts by mass of methyl methacrylate, 29.5 parts by mass of butyl acrylate, 20 parts by mass of styrene, 8 parts by mass of 2-hydroxyethyl methacrylate, and 0.0 parts by mass of acrylic acid were added. A mixed solution consisting of 5 parts by mass and 2 parts by mass of 1,1-azobis-1-cyclohexanecarbonitrile (manufactured by Wako Pure Chemical Industries, Ltd., V-40) was added dropwise over 2 hours.
After the dropwise addition was completed, the mixture was further stirred at 130° C. for 4 hours to react the remaining monomers. Thereafter, the heating was stopped and the mixture was cooled to room temperature to obtain a resin composition (base resin solution with a solid content ratio of 50% by mass) containing the (meth)acrylic resin (A-1).

The number average molecular weight of the obtained resin (A-1) was 6,000, and the weight average molecular weight was 15,000. Furthermore, the glass transition temperature of the (meth)acrylic resin (A-1) was 34° C., which was theoretically calculated from the blending ratio of the monomers used based on the above-mentioned Fox equation. Furthermore, the hydroxyl value was 35 mgKOH/g.
The above number average molecular weight and weight average molecular weight were measured and calculated by gel permeation chromatography (GPC). The equipment and conditions used are as follows.

・Equipment used: HLC8220GPC (manufactured by Tosoh Corporation)
・Column used: TSKgelSuperHZM-M, TSKgelGMHXL-H, TSKgelG2500HXL, TSKgelG5000HXL (manufactured by Tosoh Corporation)
・Column temperature: 40℃
・Standard material: TSKgel standard polystyrene A1000, A2500, A5000, F1, F2, F4, F10 (manufactured by Tosoh Corporation)
・Detector: RI (differential refraction) detector ・Eluent: Tetrahydrofuran ・Flow rate: 1ml/min

(Synthesis of resin (A-2))
Contains (meth)acrylic resin (A-2) in the same manner as resin (A-1) except that the composition of the liquid mixture dropped into the flask was as described in Table 1 below. A resin composition (base resin solution with a solid content ratio of 50% by mass) was obtained.

Information regarding resins (A-1) and (A-2) is summarized in Table 1.

<Preparation of other materials>
I prepared the following.

(Commercially available solution containing base ingredient)
Acridic WMG-521: Manufactured by DIC Corporation, acrylic resin solution for baking (non-volatile content 59-61% by mass, acid value 5.5-7.5mgKOH/g)
Acridic A-9510: Manufactured by DIC Corporation, moisture-curable silicone acrylic resin solution (non-volatile content 49-51% by mass, acid value 3.0mgKOH/g (MAX))

(pigment)
CR-97: Manufactured by Ishihara Sangyo Co., Ltd., chlorinated titanium oxide (rutile type, TiO ₂ 93%, average particle size 0.25 μm, oil absorption 17 g/100 g), product name “Tipake CR-97”
Carbon black #47: manufactured by Mitsubishi Chemical Corporation, carbon black (particle size 23 nm), product grade "#47"

(hardening agent or hardening agent-containing solution)
TKA-100: Manufactured by Asahi Kasei Corporation, isocyanurate modified form of hexamethylene diisocyanate (active ingredient 100%), product name "Duranate TKA-100"
Amidia L-125-60: Manufactured by DIC Corporation, isobutylated melamine (nonvolatile content 58-62% by mass), product name "Amidia L-125-60"
Acridic A-9585: Manufactured by DIC Corporation, moisture-curable silicone acrylic resin solution (non-volatile content 80% by mass), product name: “Acridic A-9585 (curing agent)”

(fatty acid amide or other thixotropic modifier)
The materials listed in Table 2 below were prepared.

In the above table, the peak top temperature of the melting peak of fatty acid amide is the peak top temperature of the melting peak at the time of first scan by DSC measurement under the following conditions. In this measurement, regarding fatty acid amide containing an organic solvent, the measurement was performed after the contained organic solvent was sufficiently volatilized.
・Measuring device: Heat flux differential scanning calorimeter, EXSTAR DSC 7020 manufactured by SII Nano Technology Co., Ltd.
・Weight: 5mg
・Heating rate: 10℃/min ・Measurement temperature range: -20 to 190℃
・Data analysis (identifying peak top temperature, setting baseline, etc.): Thermal analysis software Muse

(Organic solvent (thinner))
The items listed in the tables below were prepared.
"Suclean 150" in Table 8 is a petroleum hydrocarbon (mixture of C9 alkylcyclohexane) manufactured by Maruzen Petrochemical Co., Ltd.

<Manufacture of coating composition>
(Example 1)
Titanium oxide (manufactured by Ishihara Sangyo Co., Ltd., 40 parts by mass of Typeke CR-97) and 10 parts by mass of butyl acetate were added.
The mixture obtained above was sealed in a polyethylene container together with titania beads, and dispersed for 2 hours using a paint shaker, and then the titania beads were removed. In this way, a mixture of the base agent and the pigment was prepared.

Separately from the main agent-pigment mixture, a curing agent solution was added to 20 parts by mass of an isocyanate compound (isocyanurate modified product of hexamethylene diisocyanate: Duranate (trademark) TKA-100, manufactured by Asahi Kasei Corporation), and 20 parts by mass of butyl acetate. A mixture of parts by mass was prepared.

Next, a curing agent solution (20 parts by mass) was added to the main ingredient-pigment dispersion (150 parts by mass), and 30 parts by mass of butyl acetate and fatty acid amide wax (manufactured by Kusumoto Kasei Co., Ltd., Disparon PFA) were added as a diluting organic solvent. -220) were mixed together to obtain a coating composition.

Incidentally, the fatty acid amide mentioned above can be used as it is, but this time it was used as follows.
First, a product that originally had a solid content of 20% was dried using a vibration dryer (manufactured by Chuo Kakoki Co., Ltd., trade name VU-35) to form a powder with a solid content of 100%. This powder was made into a paste again using a portion of the 30 parts by mass of butyl acetate, and then mixed with other components. In this way, the influence of the organic solvent contained in the fatty acid amide wax at the time of purchase was eliminated. The same is true for all examples using PFA-220.

(Examples 2 to 36)
A coating composition was obtained in the same manner as in Example 1, except that the formulation was changed as shown in Tables 3 to 6 below.

(Supplementary information regarding fatty acid amide)
In the examples using M-1020XFS or 4401-25M (solid content not 100%) in Table 2, as in Example 1, they were first dried and made into a powder, and then made into a paste again with butyl acetate. Then, it was mixed with other ingredients.
Further, in the case of using Talen VA-750B or Disparon 308, the thixotropic agent was mixed at the time of preparation of the base agent-pigment mixture. More specifically, a specified amount of thixotropic agent was added to a polyethylene container along with other mixtures during paint shaker dispersion. At this time, heating was performed as necessary to ensure sufficient dispersion.

<Checking the dissolution state of fatty acid amide>
Each coating composition was observed using a digital microscope (manufactured by Keyence Corporation, VHX-1000) at a magnification of 100 times. In this observation, fatty acid amide-derived particles exceeding 10 μm were not observed. In other words, it was confirmed that the fatty acid amide was dissolved in the organic solvent in the coating composition or dispersed in the form of extremely small particles of 10 μm or less.

<Viscosity measurement>
The viscosity of each coating composition was measured using a B-type viscometer (model name TVB-10M) manufactured by Toki Sangyo Co., Ltd. at 25° C. and at a rotation speed of 6 rpm or 60 rpm. At each rotation speed, the viscosity was read 60 seconds after the start of rotation of the rotor (start of stirring), and η _{6 rpm} and η _{60 rpm} were determined.

<Performance evaluation>
(Painting workability (spray painting performance))
Using a gravity spray gun "W-200-201G" (nozzle diameter: 2.0 mm) manufactured by Anest Iwata Co., Ltd., each paint composition was applied to a commercially available zinc phosphate-treated steel plate (Japan Test Panel Co., Ltd.) under the following conditions. Co., Ltd., PB-144: 70 mm width x 150 mm length x 0.8 mm thickness). At this time, the state of paint ejected from the gun nozzle was observed.

[Painting conditions]
・Blow air pressure: 0.29MPa
・Cap internal pressure: 0.2MPa
・Distance between the gun and the object to be coated (length of the perpendicular line drawn from the tip of the gun nozzle to the cold-rolled steel plate): 300 mm
・Temperature: 20℃
・Spray volume: Adjust around 410mL/min ・Relative humidity: 65%

Paint workability was evaluated according to the following criteria. If the evaluation is 3 or more, it is at a practically usable level.
5: The fluidity of the paint is good and the paint is sprayed uniformly from the gun nozzle.
4: The fluidity of the paint is good, but uneven ejection may occur in rare cases.
3: The fluidity of the paint is good, but uneven ejection is occasionally observed.
2: Paint is difficult to eject from the gun nozzle, and the ejection may be interrupted.
1: Paint does not spray out from the gun nozzle and cannot be painted.

For coating compositions that were judged to have an evaluation of 3 or higher, the work was continued as is, and coating was performed so that the thickness of the coating film after drying was about 60 μm. The obtained coated product (coated cold-rolled steel sheet) was allowed to stand at room temperature (25°C) for 6 hours, and then heated at 60°C for 30 minutes. After this heating, the test plate was naturally cooled to room temperature, and the following evaluations (pattern evaluation, glossiness, and physical properties of the coating film) were performed.

However, among the physical properties of the coating film, adhesion was evaluated using a test plate (unpatterned) prepared as follows instead of the test plate (patterned) prepared as described above.

[Preparation of test plate (no pattern) for adhesion evaluation]
Approximately 100 parts by mass of toluene was added to each coating composition, and coating was performed in the same manner as in the evaluation of coating workability so that the film thickness after drying was approximately 60 μm. The obtained coated product (coated cold-rolled steel sheet) was dried at room temperature for 7 days. As a result, a test plate (patternless) with a leveled (flattened) coating surface was obtained.

(Uneven feeling (three-dimensional feeling))
Each of the test plates obtained was observed by 20 engineers with 5 years or more of experience in paint development. Specifically, when the painted surface was visually observed from a distance of 1 m from the test board, a questionnaire was conducted to determine whether or not an uneven feeling (three-dimensional effect) was felt.
The questionnaire was compiled and evaluated on a five-point scale as shown below, depending on the number of people who answered that they felt a sense of unevenness. For coating compositions with an evaluation of 3 or higher, the following (size of uneven pattern) and (uniformity of uneven pattern) were also evaluated.

5: 16 to 20 people answered that there is a feeling of unevenness (three-dimensional effect) 4: 11 to 15 people answered that there is a feeling of unevenness (three-dimensional feeling) 3: Answer that there is a feeling of unevenness (three-dimensional feeling) 6-10 people answered that it had an uneven feel (three-dimensional effect) 2: 1-5 people answered that it had an uneven feeling (three-dimensional effect) 1: 0 people answered that there was an uneven feeling (three-dimensional effect)

(size of uneven pattern)
The painted surface of each test plate was observed using a stereomicroscope with a measurement function. 100 uneven patterns (dots) were measured and arithmetic averaged to calculate the average size of the uneven patterns. They were classified as follows from A to E.

A: An extremely fine particulate uneven pattern (average size less than 0.5 mm) is formed.
B: An uneven pattern of particles having an average size of about 0.5 mm or more and less than 1.0 mm is formed.
C: An uneven pattern of particles having an average size of 1.0 mm or more and less than 1.5 mm is formed.
D: An uneven pattern of particles having an average size of 1.5 mm or more and less than 2.0 mm is formed.
E: An uneven pattern of particles having an average size of 2.0 mm or more and less than 2.5 mm is formed.

I would like to add some additional information about the size of the uneven pattern.
The preferred average size of the unevenness depends on the application of the coating film and the user's preference, so there is no general rule that any of A to E is good and which is bad.
However, the fact that it is possible to form irregularities with a relatively large average size (specifically, irregularities with sizes classified as B to E) only by spray painting is a very surprising technical effect. By using a coating composition that has such unexpected effects, it is now possible to form a coating film with a simple spray coating that previously had to be formed using a complicated method other than spray coating. Become.

(Uniformity of uneven pattern)
The painted surface of each test plate was visually observed and classified as follows. The classification was determined by discussion among three representatives of the 20 engineers mentioned above.
As a supplementary note, in the following classifications, it does not necessarily mean that X is good and Y is bad. Depending on the desired design, an uneven pattern like Y may be preferable.

X: The size of the uneven pattern is uniform throughout, with little variation.
Y: Relatively large-sized uneven patterns and small-sized uneven patterns are mixed, and the overall variation is large.

(Glossiness)
The painted surface of each test plate was visually observed, and the degree of gloss was evaluated according to the following criteria. The evaluation was determined by discussion among three representatives of the 20 engineers mentioned above.

5: The painted surface as a whole has a very high gloss.
4: Although there is some variation depending on the location, the painted surface as a whole has a high gloss.
3: Although the level of gloss is slightly low, a sense of gloss can be felt.
2: The gloss is low, and the overall gloss appears to have faded.
1: Lack of gloss, no sense of gloss at all.

(Coating film physical properties: adhesion)
A test was conducted using a test plate (unpatterned) based on JIS K5600-5-6 (1999) "Mechanical properties of coating film - Adhesion (crosscut method)". Then, the adhesion of the coating film to the substrate was evaluated based on the following criteria.

5: The edges of the cut are completely smooth, and there are no peelings on any of the grids.
4: There is small peeling of the coating film at the intersection of cuts, and the area of the peeled part is less than 5%.
3: The area of the peeled portion is 5% or more and less than 15%.
2: The area of the peeled portion is 15% or more and less than 35%.
1: The area of the peeled part is 35% or more.

(Coating film physical properties: water resistance)
The test plate was immersed in warm water at 40° C. for 10 days according to a method based on JIS K 5600-6-2 “Chemical properties of coating films - Liquid resistance (water immersion method)”. After 10 days, the test plate was removed from the hot water and dried at room temperature for 24 hours. The state of the coating film while immersed in warm water and the state of the coating film after drying were each visually observed and evaluated using the following criteria.

5: No change in the appearance of the coating film was observed both during immersion and after drying.
4: Slight whitening is observed in the coating film during dipping, but no change is observed after drying.
3: Slight whitening is observed both during soaking and after drying.
2: During dipping, the coating film significantly whitened, and after drying, slight changes such as decreased gloss and whitening were observed.
1: In addition to significant whitening of the paint film during immersion, significant changes such as decreased gloss and whitening are observed even after drying of the paint film.

Information regarding the composition, viscosity, and performance evaluation of each coating composition is summarized in Tables 3 to 6.

As shown in Examples 3 to 7, 9, and 11 in Table 3, and Examples 12 to 18 in Table 4, it contains a base agent, a curing agent, and a fatty acid amide, and the content of fatty acid amide in 100 parts by mass of the coating film component is To obtain a coated object having a coating film with an uneven feeling (three-dimensional effect) without requiring any special additional steps by spray painting a coating composition of 2.5 to 15 parts by mass on a substrate. was completed.
On the other hand, as shown in Tables 5 and 6, a coating composition that does not contain fatty acid amide, a coating composition that contains fatty acid amide but in a very small amount, or a coating composition that contains a thixotropic modifier different from fatty acid amide. Even when spray-painted on a base material, it was not possible to form a coating film with sufficient unevenness (three-dimensional effect) (the unevenness (three-dimensional effect) was 2 or less).

A closer look at Tables 3 to 6 reveals the following.
- In the coating compositions of Examples 1, 2, 8, and 10 described as "Reference" in Table 3, the amount of fatty acid amide in 100 parts by mass of the coating film component is 2.5 parts by mass or less. In the evaluation of these coating compositions, the unevenness was rated "3", and compared to Example 3, the unevenness was somewhat lacking. Furthermore, when the amount of amide is small, the size of the uneven pattern tends to become smaller.
- In each of the examples in Tables 3 and 4, the evaluation results of "glossiness" were also good.
- In Examples 17 and 18, the evaluation results of the unevenness and the size of the uneven pattern were good. However, the evaluation results of the physical properties of the coating film are inferior to the evaluation results of the physical properties of the coating film of other examples. It is considered that by appropriately reducing the amount of fatty acid amide, it is possible to form a coating film having an uneven pattern and to improve the physical properties of the coating film.

<Additional example: Change of organic solvent (thinner)>
Based on the coating composition of Example 14, coating compositions (Examples 2-1 to 2-15) were prepared in which the organic solvent (thinner) was changed. Then, various evaluations similar to those described above were performed.
Information regarding the composition, viscosity, and performance evaluation of the coating composition is summarized in Tables 7 and 8.

Tables 7 and 8 show that as long as the coating composition contains a base agent, a curing agent, and a fatty acid amide, and the content of the fatty acid amide is appropriately high, the coating film having an uneven pattern ( It is understood that it is possible to form a cured film).
However, considering that in Example 2-5, in which only cyclohexanone (boiling point 155°C) was used as the thinner, the unevenness (three-dimensional effect) was evaluated as "3", it is considered that the relatively low boiling point (boiling point 150°C It is thought that by using a relatively large amount of thinner (described below), a better unevenness (three-dimensional effect) can be obtained.

<Additional example: Use of resin with crosslinked structure>
Based on the coating composition of Example 2-11, coating compositions (Examples 3-1 to 3-3) were prepared using a resin (A-2) having a crosslinked structure as a part of the main component. Then, various evaluations similar to those described above were performed.
Information regarding the composition, viscosity, and performance evaluation of the coating composition is summarized in Table 9.

In Example 2-11 (reposted), the size of the uneven pattern was "B", but in Examples 3-1 to 3-3 containing resin (A-2), the size of the uneven pattern was "D". Or it was "E". In other words, it is understood that a larger uneven pattern can be formed by using a coating composition containing resin (A-2).

<Additional example: Change of pigment>
Based on the coating composition of Example 2-11, coating compositions (Examples 4-1 and 4-2) using carbon black as part or all of the pigment were prepared. Then, various evaluations similar to those described above were performed.
Information regarding the composition, viscosity, and performance evaluation of the coating composition is summarized in Table 10.

Examples 4-1 and 4-2 show that it is possible to form a coating film (cured film) having an uneven pattern not only when using a titanium oxide pigment but also when using a carbon black pigment.

<Additional example: Coating composition different from isocyanate curing system>
All of the above examples were curing systems that were cured by reaction of hydroxy groups in the resin with an isocyanate curing agent. We show that it is possible to form a coating film (cured film) with an uneven pattern in other curing systems as well, by containing a base agent, a curing agent, and a fatty acid amide, and by containing a suitably large amount of fatty acid amide. .

First, a pigment and an organic solvent were added to a base solution according to the formulation shown in Table 11 below to form a mixture. The mixture was sealed in a polyethylene container together with titania beads, and dispersed for 2 hours using a paint shaker. Thereafter, the titania beads were removed. In this way, a base agent-pigment dispersion was prepared.
In addition, apart from the base pigment-pigment dispersion, a curing agent solution having the formulation shown in Table 11 below was prepared.

Next, a curing agent solution was added to the base pigment-pigment dispersion, and an organic solvent (thinner, 3 types listed in Table 11) and fatty acid amide were mixed respectively to form coating compositions (Examples 5-1 and 5- 2) was obtained.
Using the obtained coating composition, various evaluations similar to those for other coating compositions were performed. However, the curing conditions were as follows.
Example 5-1: After standing at room temperature (25°C) for 6 hours, heat at 80°C for 30 minutes.
Example 5-2: Leave at room temperature (25°C) for one week.

Information regarding the composition, viscosity, and performance evaluation of the coating composition is summarized in Table 11.

From Examples 5-1 and 5-2, even in a curing system that is not a hydroxy group-isocyanate curing system, a coating composition containing a base agent, a curing agent, and a fatty acid amide and containing a moderately large amount of fatty acid amide has an uneven pattern. It is understood that a coating film (cured film) can be formed.

<Additional example: Change of painting conditions>
A cold-rolled steel sheet was spray coated in the same manner as in Example 3, except that the blowing air pressure was changed at several points between 0.05 and 1.0 MPa. In this case as well, a coating film having an uneven pattern could be formed.
In addition, a cold rolled steel plate was spray coated in the same manner as in Example 3, except that the distance between the object to be coated and the discharge part of the spray gun was changed in several points between 10 and 100 cm. In this case as well, a coating film having an uneven pattern could be formed.

Claims (30)

The coating film component includes at least a base agent, a curing agent, and a fatty acid amide, and the content of the fatty acid amide in 100 parts by mass of the coating film component is 2.5 to 15 parts by mass,
Furthermore, it contains organic solvents as volatile components,
The fatty acid amide is dissolved in the organic solvent, or is dispersed in the organic solvent as particles with a particle size of 10 μm or less, and when observed with a microscope, fatty acid amide-derived particles with a particle size of more than 10 μm are found. paint composition that is not observed,
A method for producing a coated article, which includes spray painting the surface of the coated article using a spray gun to produce a coated article having a coating film having an uneven pattern. A method for manufacturing a coated article according to claim 1, comprising:
The spray painting is a method for manufacturing a coated object, in which the spray painting is performed under the following conditions.
[conditions]
・Blowing air pressure: 0.05-1.0MPa
・Distance between the object to be coated and the spray gun discharge part: 10 to 100 cm A method for manufacturing a coated article according to claim 1 or 2, comprising:
The method for producing a coated article, wherein the organic solvent includes a low boiling point organic solvent having a boiling point of 150°C or less. The method for manufacturing a coated article according to claim 3 ,
A method for producing a coated article, wherein the proportion of the low boiling point organic solvent in the organic solvent is 25% by mass or more. A method for producing a coated article according to any one of claims 1 to 4, comprising:
A method for producing a coated article, wherein the coating composition has a viscosity η _{6 rpm} of 0.2 to 50 Pa·s as measured using a B-type viscometer at 25° C. and a rotation speed of 6 rpm. A method for producing a coated article according to any one of claims 1 to 5, comprising:
A method for producing a coated article, wherein the coating composition has a viscosity η _{60 rpm} of 0.03 to 25 Pa·s as measured using a B-type viscometer at 25° C. and a rotation speed of 60 rpm. A method for producing a coated article according to any one of claims 1 to 6, comprising:
The coating composition further includes a pigment as a coating film component. The method for producing a coated article according to any one of claims 1 to 7,
The method for producing a coated article, wherein the main agent includes a (meth)acrylic resin. The method for producing a coated article according to any one of claims 1 to 8,
A method for producing a coated article, wherein the main agent includes a polymer having a branched structure and/or a crosslinked structure. A coating composition for forming a coating film having an uneven pattern by spray coating,
Coating film components include at least a base agent, a curing agent, and a fatty acid amide,
The content of the fatty acid amide in 100 parts by mass of the coating film component is 2.5 to 15 parts by mass,
Furthermore, it contains an organic solvent as a volatile component,
The fatty acid amide is dissolved in the organic solvent, or is dispersed in the organic solvent as particles with a particle size of 10 μm or less, and when observed with a microscope, fatty acid amide-derived particles with a particle size of more than 10 μm are found. Paint composition not observed. The coating composition according to claim 10,
The organic solvent is a coating composition containing a low boiling point organic solvent having a boiling point of 150° C. or lower. The coating composition according to claim 11 ,
A coating composition wherein the proportion of the low boiling point organic solvent in the organic solvent is 25% by mass or more. The coating composition according to any one of claims 10 to 12,
A coating composition whose viscosity η 6 rpm measured using a B-type viscometer at 25° C. and a rotation speed of 6 rpm _is 0.2 to 50 Pa·s. The coating composition according to any one of claims 10 to 13,
A coating composition having a viscosity η _{60 rpm} of 0.03 to 25 Pa·s as measured using a B-type viscometer at 25° C. and a rotation speed of 60 rpm . The coating composition according to any one of claims 10 to 14,
A coating composition further containing a pigment as a coating component. The coating composition according to any one of claims 10 to 15,
The main agent is a coating composition containing a (meth)acrylic resin. The coating composition according to any one of claims 10 to 16,
A coating composition in which the main agent includes a polymer having a branched structure and/or a crosslinked structure. Using a spray gun, a coating composition containing at least a base agent, a curing agent, and a fatty acid amide as a coating film component, and in which the content of the fatty acid amide in 100 parts by mass of the coating film component is 2.5 to 15 parts by mass. a spray painting process in which the surface of the object to be coated is sprayed;
A baking process that involves heating at 60 to 180°C;
A method for producing a coated object comprising a coating film having an uneven pattern. Using a spray gun, a coating composition containing at least a base agent, a curing agent, and a fatty acid amide as a coating film component, and in which the content of the fatty acid amide in 100 parts by mass of the coating film component is 2.5 to 15 parts by mass. A method for manufacturing a coated article having a coating film having an uneven pattern, which includes a spray coating step of spraying the surface of the article to be coated, but does not include a baking step. The method for manufacturing a coated article according to claim 19,
A method for producing a coated article, which comprises, after the spray coating step, a room temperature drying step of drying the painted coating composition at room temperature. The method for producing a coated article according to any one of claims 18 to 20,
The spray painting is a method for manufacturing a coated object, in which the spray painting is performed under the following conditions.
[conditions]
・Blowing air pressure: 0.05-1.0MPa
・Distance between the object to be coated and the spray gun discharge part: 10 to 100 cm The method for producing a coated article according to any one of claims 18 to 21,
The coating composition further includes an organic solvent as a volatile component. 23. The method for manufacturing a coated article according to claim 22,
The method for producing a coated article, wherein the organic solvent includes a low boiling point organic solvent having a boiling point of 150°C or less. 24. The method for manufacturing a coated article according to claim 23,
A method for producing a coated article, wherein the proportion of the low boiling point organic solvent in the organic solvent is 25% by mass or more. The method for producing a coated article according to any one of claims 22 to 24,
A method for producing a coated article, wherein the fatty acid amide is dissolved in the organic solvent or dispersed in the organic solvent as particles with a particle size of 10 μm or less. The method for producing a coated article according to any one of claims 18 to 25,
A method for producing a coated article, wherein the viscosity η 6 rpm of the coating composition measured using a B-type viscometer at 25° C. and a rotation speed of _{6 rpm} is 0.2 to 50 Pa·s. The method for producing a coated article according to any one of claims 18 to 26,
A method for producing a coated article, wherein the coating composition has a viscosity η _{60 rpm} of 0.03 to 25 Pa·s as measured using a B-type viscometer at 25° C. and a rotation speed of 60 rpm. The method for producing a coated article according to any one of claims 18 to 27,
The coating composition further includes a pigment as a coating film component. The method for producing a coated article according to any one of claims 18 to 28,
The method for producing a coated article, wherein the main agent includes a (meth)acrylic resin. The method for producing a coated article according to any one of claims 18 to 29,
A method for producing a coated article, wherein the main agent contains a polymer having a branched structure and/or a crosslinked structure.