JP2001240805A - Coating composition - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a coating material having good mixing stability and a sufficiently long pot life, giving an excellently finished state, having excellent interlaminar adhesivity, capable of preventing the peeling, blistering and cracking of the coating film, and forming a coating film having excellent stainproofness. SOLUTION: The objective composition contains (A) an organic resin, (B) a compound consisting of a condensation product of a tetraalkoxysilane having an average condensation degree of 4-20, containing 1-3C alkyl groups and 4-12C alkyl groups in mixed state as the alkyl groups of the condensation product at a mixing ratio of the 4-12C alkyl groups of 5-50% based on the total alkyl groups in the condensation product and (C) an organic acid. The amount of the component B is 1.0-50.0 pts.wt. in terms of SiO2 and that of the component C is 0.1-30 pts.wt. based on 100 pts.wt. of the solid resin content of the component A.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a coating composition used for surface finishing of various materials such as metal, glass, porcelain tile, concrete, siding board, extruded plate, plastic and the like.

[0002]

2. Description of the Related Art Conventionally, paint finishing has been carried out to protect the frame of a building, civil engineering structure, etc., to impart designability, and to improve the aesthetic appearance, such as fluorine resin paint, acrylic silicone resin paint or polyurethane resin paint. Highly durable paints are preferred. However, recently, especially in the city center and the suburbs, there are many oily contaminants floating in the air due to exhaust gas from automobiles and the like, and these oily contaminants adhere to the coating film surface, The problem is that significant soot or streak contamination occurs.

[0003] On the other hand, various paints have been disclosed in which the surface of a coating film is made hydrophilic, and adhered oily contaminants are separated and washed away by the action of rainwater during rainfall spreading on the coating film surface. For example, Japanese Patent Application No. 6-506632 (International Publication WO94 / 06870) proposes to mix an organosilicate in a paint.

[0004]

By the way, usually, when paint is applied to a building or the like on site, it is difficult to apply the paint only once because of the unevenness of the base and uneven suction.
It is easy to cause uneven coating and gloss finish, and it is difficult to obtain a highly aesthetic finish. If thick coating is performed to prevent this, problems such as the occurrence of paint dripping will occur. Therefore, in order to obtain a good finished appearance, a method of applying the same paint a plurality of times has been preferred. On the other hand, if a partial scratch, uneven coating, or the like is found after completion of the coating, repair coating with the same coating is performed. As described above, in the case of on-site painting on a building or the like, the same paint is most often applied twice or more.

However, the paint disclosed in the above publication has low stability when the organosilicate is mixed, and has drawbacks such as generation of agglomerates, gelation, and phase separation in a short time. For this reason, a problem is likely to occur in that the second coating cannot be performed even if the second coating is performed, or that even if the coating can be performed, a good finish cannot be obtained due to polishing and the like.

Furthermore, the paint disclosed in the above publication has a drawback that when coating is performed a plurality of times, the adhesion between the layers is significantly reduced when the interval is long. For this reason, a problem which cannot be ignored in practical use, such as peeling of the applied coating film or blistering or cracking of the coating film with time, tends to occur.

[0007]

Means for Solving the Problems In order to solve such a problem, the present inventors have conducted intensive studies and as a result, have made organic resins contain specific amounts of specific alkoxysilane compounds and organic acids. As a result, no agglomerates are generated, the mixing stability is good, the pot life is sufficient, excellent finish (high gloss value in gloss enamel) can be ensured, and the interlayer adhesion is excellent. , Peeling of coating film,
It has been found that blisters and cracks can be prevented, and furthermore, a coating film having excellent stain resistance can be obtained, and the present invention has been completed.

That is, the present invention relates to the following coating composition:
It is. 1. (A) organic resin, (B) tetraalkoxysilane
Is a condensate having an average degree of condensation of 4 to 20;
Alkyl groups having 1 to 3 carbon atoms and 4 to 12 carbon atoms are mixed
And the mixture ratio is 4 to 12 carbon atoms.
The alkyl group accounts for 5 to 50% of the total alkyl groups in the condensate.
Resin containing (C) an organic acid, and a component (A)
The component (B) is SiO ₂Exchange
1.0 to 50.0 parts by weight in total, and 0.1 to 3 parts by weight of component (C).
A coating composition comprising 0 parts by weight. 2. (A) that the component is an amino group-containing organic resin
Features 1. 3. The coating composition according to item 1. 3. Further, (D) the amine compound is added to the resin (A)
0.02-5.0 parts by weight per 100 parts by weight of solids
It is characterized by having 1. 3. The coating composition according to item 1. 4. Further, (E) a polymer having 2 to 40 repeating units.
Weight average molecular weight 1 containing alkylene oxide chain
50 to 3500 alkoxysilane compounds,
Per 100 parts by weight of resin solids per minute
1 to 20 parts by weight. ~ 3. No
A coating composition according to any of the preceding claims. 5. More than 50% by weight of the total solvent in the paint is aliphatic coal
1. Hydrogen hydride ~ 4. Paint composition according to any of the above
object.

[0009]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, the present invention will be described in detail based on its embodiments.

[(A) Organic Resin] The organic resin, which is the component (A) in the composition of the present invention, is used as a binder for paints, and known organic resins can be used.

The type of the resin as the component (A) is not particularly limited, and examples thereof include a polyester resin, an acrylic resin, a fluorine resin, an alkyd resin, or the like, or an alkyd-modified acrylic resin, a silicon-modified acrylic resin, or a polyester. Modified resins such as modified acrylic resins,
One or more of various resins can be used. As the form of the resin, a solution form, a dispersion form, or a mixed form thereof can be used.

As the component (A) of the present invention, those having a weight average molecular weight of 5,000 to 200,000 can be used. When the weight average molecular weight is less than 5,000, appropriate viscosity is not obtained as a paint, and the properties of each coating film are inferior. On the contrary, when the weight average molecular weight is more than 200,000, the sharpness and gloss of the coating film are deteriorated, which is preferable. Absent.

The glass transition point of the component (A) is from -10 ° C to 1
The temperature is preferably 50C, more preferably 10C to 100C. When the temperature is lower than -10 ° C, the soil removal property and the soil recovery property are poor. When the temperature is higher than 150 ° C, flexibility and durability are poor.

In the present invention, a compound containing a hydroxyl group as a functional group, that is, a polyol compound is preferably used from the viewpoint that durability can be improved by a crosslinking reaction.

(Polyol compound) Examples of the polyol include polyether polyol, polyester polyol, acrylic polyol, fluorine-containing acrylic polyol, silicone-containing acrylic polyol and the like. Hereinafter, each polyol will be exemplified.

(1) Polyether polyol The polyether polyol is one of polyhydric alcohols such as ethylene glycol, diethylene glycol, propylene glycol, dipropylene glycol, glycerin, trimethylolpropane, pentaerythritol, glucose, sorbitol and sucrose. Or 2
Propylene oxide, ethylene oxide,
Examples thereof include polyols obtained by adding one or more kinds such as butylene oxide and styrene oxide, and polyoxytetramethylene polyols obtained by adding tetrahydrofuran to the polyhydric alcohol by ring-opening polymerization.

(2) Polyester polyol Polyester polyols include ethylene glycol, propylene glycol, butanediol, pentanediol, hexanediol, cyclohexanedimethanol, glycerin, trimethylolpropane, pentaerythritol and other low molecular weight polyhydric alcohols. Species or two or more and one or two of glutaric acid, adipic acid, pimelic acid, speric acid, sebacic acid, terephthalic acid, isophthalic acid, dimer acid, hydrogenated dimer acid or other low molecular dicarboxylic acids or oligomeric acids Condensation polymer with the above, propiolactone, caprolactone,
Examples thereof include polyols such as ring-opening polymers of ring-opening esters such as valerolactone.

(3) Acrylic polyol The acrylic polyol is obtained by copolymerizing a hydroxyl group-containing acrylic monomer and another polymerizable monomer. Examples of the hydroxyl group-containing acrylic monomer include 2-hydroxyethyl (meth) acrylate, 2-hydroxypropyl (meth) acrylate,
Hydroxyalkyl esters of (meth) acrylic acid such as -hydroxypropyl (meth) acrylate, 2-hydroxybutyl (meth) acrylate, 4-hydroxybutyl (meth) acrylate, 2-hydroxypentyl (meth) acrylate, glycerin, trimethylol Examples include (meth) acrylic acid monoesters of polyhydric alcohols such as propane, and N-methylol (meth) acrylamide.

Other polymerizable monomers include methyl (meth) acrylate, ethyl (meth) acrylate,
n-butyl (meth) acrylate, i-butyl (meth)
Alkyl group-containing (meth) acrylic monomers such as acrylate, 2-ethylhexyl (meth) acrylate and cyclohexyl (meth) acrylate; ethylenically unsaturated carboxylic acids such as (meth) acrylic acid; dimethylaminoethyl (meth) acrylate Amino group-containing (meth) acrylic monomers such as dimethylaminopropyl (meth) acrylate; amide-containing (meth) acrylic monomers such as (meth) acrylamide and ethyl (meth) acrylamide; nitrile groups such as acrylonitrile Containing (meth) acrylic monomer; epoxy group-containing (meth) acrylic monomer such as glycidyl (meth) acrylate; aromatic hydrocarbon-based vinyl monomer such as styrene, methylstyrene, chlorostyrene, and vinyltoluene ; Styrene sulfonic acid, vinyls Sulfonic acid-containing vinyl monomers such as acids, vinyl acetate, vinyl propionate, vinyl butyrate, vinyl esters such as vinyl pivalate and the like.

Further, it is possible to modify the acrylic polyol with silicone by copolymerizing a reactive silyl group-containing vinyl monomer. Examples of the reactive silyl group-containing vinyl monomer include vinyltrimethoxysilane, vinyltriethoxysilane, vinyltri-n-butoxysilane, and vinyltris (β-methoxyethoxy).
Silane, allyltrimethoxysilane, trimethoxysilylethyl vinyl ether, triethoxysilylethyl vinyl ether, trimethoxysilylpropyl vinyl ether, triethoxysilylpropyl vinyl ether, γ
-(Meth) acryloyloxypropyltrimethoxysilane, γ- (meth) acryloyloxypropyltriethoxysilane, γ- (meth) acryloyloxypropylmethyldimethoxysilane, vinylmethyldimethoxysilane, methyldimethoxysilylethyl vinyl ether,
Methyl dimethoxysilylpropyl vinyl ether and the like.

(4) Fluorine-containing polyol The fluorine-containing polyol is a fluoroolefin monomer,
It is obtained by copolymerizing a fluorine monomer such as a fluoroalkyl group-containing acrylic monomer, a hydroxyl group-containing vinyl monomer, and another polymerizable monomer as necessary. . As the fluoroolefin monomer, perfluoroolefins such as tetrafluoroethylene, chlorotrifluoroethylene, and hexafluoropropylene,
Examples thereof include vinyl fluoride and vinylidene fluoride. Examples of the fluoroalkyl group-containing acrylic monomer include perfluoromethyl methacrylate, perfluoroisononylmethyl methacrylate, 2-perfluorooctylethyl acrylate, 2-perfluorooctylethyl methacrylate, and the like.

Examples of the hydroxyl group-containing vinyl monomer include hydroxyalkyl vinyl ethers such as hydroxyethyl vinyl ether, hydroxypropyl vinyl ether, hydroxybutyl vinyl ether and hydroxypentyl vinyl ether; ethylene glycol monoallyl ether, diethylene glycol monoallyl ether, and triethylene glycol monoallyl. And hydroxy allyl ethers such as ethers. As the other polymerizable monomer, the monomers shown in the above acrylic polyol and the like can be appropriately used.

(5) Silicone-containing polyol The silicone-containing polyol is obtained by introducing a silicone component into a polyol. The method of introducing such a silicone component is not particularly limited, and various methods can be adopted.For example, a method of copolymerizing a silicone compound having a polymerizable double bond, A method of reacting the functional group with a silicone compound having a functional group capable of reacting; a method of reacting a reactive silyl group-containing compound with a resin obtained by copolymerizing a reactive silyl group-containing vinyl monomer; After reacting the functional group with a coupling agent having a functional group capable of reacting with the functional group, and then reacting a reactive silyl group-containing compound.

Examples of the combination of the functional groups include a hydroxyl group and an isocyanate group, a hydroxyl group and a carboxylic anhydride group, an amino group and an isocyanate group, a carboxyl group and an epoxy group, an amino group and an epoxy group, and an alkoxysilyl group. Can be

As the reactive silyl group in the above,
An alkoxyl group, a phenoxy group, a mercapto group, an amino group, a halogen, etc. are bonded to a silicon atom. As the reactive silyl group-containing compound, those having two or more reactive silyl groups in one molecule are used. For example, tetrafunctional alkoxysilanes such as tetraethoxysilane, tetramethoxysilane and tetrabutoxysilane; Trifunctional alkoxysilanes such as methoxysilane and methyltriethoxysilane; bifunctional alkoxysilanes such as dimethyldimethoxysilane and dimethyldiethoxysilane; chlorosilanes such as tetrachlorosilane and methyltrichlorosilane; tetraacetoxysilane and methyltriacetoxysilane And the like, and one or more of these can be used. Further, a compound having one reactive silyl group in one molecule can be used in combination.

Examples of the reactive silyl group-containing vinyl monomer in the above include the same monomers as those used when modifying the acrylic polyol.

The coupling agent in the above is, for example, a compound having at least one or more alkoxysilyl groups and other substituents in one molecule. Specific examples of the coupling agent include γ-glycidoxypropylmethyldiethoxysilane, γ-aminopropyltrimethoxysilane, isocyanate-functional silane, and γ-methacryloxypropyltrimethoxysilane.

(6) Other polyols In addition, phenolic resin polyols, epoxy polyols, polybutadiene polyols, polyisoprene polyols, polyester-polyether polyols, polymer polyols obtained by adding or dispersing polymers such as acrylonitrile and styrene, and urea dispersion Polyols, carbonate polyols and the like can be used as the polyol of the present invention.

In the present invention, one or more of such polyols can be used. Among them, acrylic polyol, silicon-modified acrylic polyol,
The use of a fluorine-containing polyol or a silicone-containing polyol is preferable because the weather resistance of the coating film can be improved. The use of a silicone-modified acrylic polyol or a silicone-containing polyol is preferable in that the adhesion to various types of substrates can be improved.

When the above polyol is used, it is preferable to use a polyol having a hydroxyl value of 15 to 100 KOH mg / g. Hydroxyl value is 15KOHm
If it is less than g / g, the crosslink density is low, so that various coating film properties and stain resistance are inferior.
When it is larger than g, the crosslink density becomes high, and the surface orientation of the (B) tetraalkoxysilane low-condensate is undesirably hindered.

In the present invention, by using an amino group-containing organic resin as the component (A), the interlayer adhesion of the formed coating film can be further enhanced. The amino group of the component (A) is at least one selected from a primary amino group-containing monomer, a secondary amino group-containing monomer, and a tertiary amino group-containing monomer. Can be provided by copolymerizing

Examples of the primary amino group-containing monomer include aminomethyl (meth) acrylate, aminoethyl (meth) acrylate, aminopropyl (meth) acrylate, aminobutyl (meth) acrylate, p-aminostyrene, Allylamine and the like can be mentioned.

Examples of the secondary amino group-containing monomer include monomethylaminoethyl (meth) acrylate, N
-Methyl (meth) acrylamide, N-ethyl (meth)
Acrylamide, N-methylolacrylamide, N-
(4-anilinophenyl) methacrylamide and the like.

Examples of the tertiary amino group-containing monomer include dimethylaminomethyl (meth) acrylate, dimethylaminoethyl (meth) acrylate, diethylaminoethyl (meth) acrylate and methylethylaminoethyl (meth) acrylate. Esters of acrylic acid or methacrylic acid; dimethylaminomethyl (meth)
(Meth) acrylamide compounds such as acrylamide and dimethylaminoethyl (meth) acrylamide; styrene derivatives such as dimethylaminoethylstyrene; and pyridyl group-containing vinyl compounds such as 2-vinylpyridine.

When the component (A) contains a polyol, a compound containing a tertiary amino group in which three carbon atoms are bonded to a nitrogen atom can be most preferably used as the amino group. This is because the NH group present in the primary amino group and the secondary amino group is changed to the NC of the isocyanate compound.
This is because it easily reacts with the O group and reacts faster than urethane bond formation to form a urea bond, which slightly affects the properties of the coating film. However, even if an NH group is present, there is no practical problem even if an amino group having NH is used if the total content is appropriately adjusted.

[(A ′) Curing agents] When the component (A) contains a polyol, an isocyanate compound (hereinafter referred to as “A”)
A coating film is formed by blending an “(A′-1) component”), an organometallic compound (hereinafter, referred to as a “(A′-2) component”), and crosslinking and curing.

As the component (A'-1), toluene diisocyanate (TDI), 4,4-diphenylmethane diisocyanate (pure-MDI), polymeric M
DI, xylylene diisocyanate (XDI), hexamethylene diisocyanate (HMDI), isophorone diisocyanate (IPDI), hydrogenated XDI, hydrogenated MDI
Derivatized isocyanate monomers such as allophanate, biuret, dimer (uretidion), trimer (isocyanurate), adduct, carbodiimidation, and the like, and mixtures thereof can be used. . In particular, in consideration of yellowing of a formed coating film, it is preferable to use an aliphatic or alicyclic polyisocyanate or a mixture thereof.

Further, these components (A'-1) can be used in the form of a blocked isocyanate using a blocking agent such as alcohols, phenols, ε-caprolactam, oximes and active methylene compounds.

The components (A'-1) and (A) are mixed in such a ratio that the NCO / OH ratio becomes 0.7 to 2.0, preferably 0.8 to 1.5. Do. At this time, if the NCO / OH ratio is smaller than 0.7, the cross-linking ratio of the coating film becomes low, and the curability and durability are deteriorated. In addition, the contaminants penetrate into the coarse molecules of the coating film. Even if cleaning is performed, it is difficult to remove contaminants, and the recovery from contamination is poor. On the other hand, if it is larger than 2.0, unreacted isocyanate remains, deteriorating the initial drying property, causing tackiness on the surface called tack and contaminants being physically attached, On the contrary, the initial contamination is inferior.

As the component (A'-2), for example, dibutyltin dilaurate, dibutyltin dimalate, dioctyltin dilaurate, dioctyltin dimalate,
Organic tin compounds such as tin octylate; metal chelate compounds such as aluminum tris (acetylacetonate), titanium bis (acetylacetonate) and zirconium bis (butoxy) bis (acetylacetonate).

When the component (A'-2) is blended, the blending amount is usually 0.0
A range of 2 to 10 parts by weight is preferred. When the blending amount of the component (A'-2) exceeds 10 parts by weight, the finish of the obtained coating film tends to decrease.

[(B) Tetraalkoxysilane Low Condensate] In the present invention, a tetraalkoxysilane low condensate having a specific structure (hereinafter, referred to as “component (B)”) is blended. The component (B) is a condensate of tetraalkoxysilane having an average degree of condensation of 4 to 20, wherein the alkyl group in the condensate contains a mixture of alkyl groups having 1 to 3 carbon atoms and 4 to 12 carbon atoms. Wherein the alkyl group having 4 to 12 carbon atoms is 5 to 50% of the total alkyl groups in the condensate.

The component (B) is a low-condensation product of tetraalkoxysilane, but the one having a high degree of condensation (average degree of condensation is greater than 20) and a high molecular weight are difficult to manufacture and are difficult to handle due to an increase in viscosity. It is not preferable because it is inconvenient. Conversely, those having an average degree of condensation of 3 or less and a low molecular weight are not preferred because they have high volatility and are also inconvenient to handle.

In addition, the compatibility of the component (A) with the component (A) is drastically improved because the alkyl group in the component (B) contains one having 1 to 3 carbon atoms and 4 to 12 carbon atoms. A film having excellent surface orientation and excellent film properties can be formed. If the alkyl group is only an alkyl group having 1 to 3 carbon atoms, the compatibility with the component (A) is poor and the surface orientation is poor. Further, when only an alkyl group having 4 to 12 carbon atoms is used, the stain resistance is remarkably deteriorated, which is not preferable. The presence of an alkyl group having 13 or more carbon atoms is not preferred because stain resistance is deteriorated. In addition, as the number of carbon atoms in the alkyl group increases, the hydrolysis reaction tends to be less likely to occur. Therefore, it is not preferable that only alkyl groups having a large number of carbon atoms exist. (B)
The component comprises about 5 to 5 of the total alkyl groups of the low condensate.
The one in which 50% is an alkyl group having 4 to 12 carbon atoms is preferable because it has excellent compatibility with the component (A) and excellent stain resistance of the coating film.

The component (B) of the present invention can be produced by the following method, but is not limited thereto. General formula Si (OR ¹ ) (OR ² ) (OR ³ ) (OR ⁴ ) (wherein, R ^{1 to} R ⁴ are a mixture of an alkyl group having 1 to 3 carbon atoms and an alkyl group having 4 to 12 carbon atoms. Average condensation degree of 4 to 2
0, condensation is performed so that the weight average molecular weight is 500-3500. The condensation method is based on a known method.

In the formula, a part of the alkyl group represented by R ^{1 to} R ⁴ is
By having a mixture of one having 1 to 3 carbon atoms and one having 4 to 12 carbon atoms, the compatibility with the component (A) is dramatically improved, the surface orientation is excellent, and the coating film properties are excellent. A film can be formed. When such a tetraalkoxysilane is condensed to form a low condensate, about 5 to 50% of all alkyl groups are alkyl groups having 4 to 12 carbon atoms (A). It is preferable because it has excellent compatibility with the components and excellent stain resistance of the coating film.
In order to make the alkyl group of about 5 to 50% of the total, at the time of condensation, another alkyl silicate (the alkyl group having 1 to 3 carbon atoms) is mixed and condensed. It is an effective means.

Specific examples include, but are not limited to, low-condensates such as monobutoxytrimethoxysilane, monopentoxytrimethoxysilane, monohexoxytrimethoxysilane, dibutoxydiethoxysilane and the like. .

(A) General formula R ⁵ O (Si (OR ⁵ ) ₂ O) _n R ⁵ (where R ⁵ is an alkyl group having 1 to 3 carbon atoms, and n is 4
An alkyl silicate low-condensate (hereinafter, referred to as “component (a)”) represented by the following general formula: R ⁶ OH (where R ⁶ is a group having 4 to 12 carbon atoms) Using an alcohol represented by the following formula (hereinafter referred to as "component (b)"), about 5 to 50% of the alkyl group portion of component (a) is transesterified.

As the component (a), specifically, tetramethyl silicate, tetraethyl silicate, tetra-n
Low-condensates such as -propyl silicate and tetra-i-propyl silicate. In particular, tetramethyl silicate and tetraethyl silicate are generally used. The average degree of condensation is preferably from 4 to 20, and it is not preferable that the average degree of condensation is large or small because handling becomes inconvenient. As the component (b), specifically, n-butyl alcohol, n-amyl alcohol, n-hexyl alcohol, n-heptyl alcohol, n-octyl alcohol, n-nonyl alcohol, n-decyl alcohol, n
-Undecyl alcohol and n-dodecyl alcohol.

When the component (a) is transesterified with the component (b), all the alkyl groups (R ⁵ ) of the component (a)
Is not transesterified to the alkyl group (R ⁶ ) of the component (b), but a transesterification of about 5 to 50% of the total alkyl group of the component (a) is used. As for the exchange ratio, the ester exchange may be performed using 1 to 12 moles of the component (b) with respect to 1 mole of the component (a). The exchange ratio is appropriately adjusted depending on the average degree of condensation of the component (a).
By transesterifying 0%, the compatibility with the component (A) and the stain resistance of the coating film can be made excellent. When the transesterification rate is low, the compatibility becomes poor and the surface orientation becomes insufficient. When the transesterification rate is high, the hydrolysis reaction is less likely to occur, the coating film is less likely to be hydrophilic, and the stain resistance tends to be worse.

The component (B) thus produced is
With respect to 100 parts by weight of the resin solid content of the component (A), SiO
1.0 to 50.0 parts by weight, preferably 2.0 to 3 parts by weight in terms of ₂
0.0 parts by weight can be added. This is because if the amount is less than 1.0 part by weight, the hydrophilicity of the coating film is not sufficient, so that the stain resistance is inferior. If the amount exceeds 50.0 parts by weight, the appearance of the cured coating film deteriorates and cracks occur. Is to come out.

Here, SiO₂Conversion means alkoxysila
Compounds with Si-O bonds, such as
After being completely hydrolyzed, when calcined at 900 ° C, silica
(SiO₂)
You. In general, alkoxysilanes and silicates react with water
In response, a hydrolysis reaction occurs to form silanol,
Condensation reaction between silanols or silanol and alkoxy
It has the nature to respond. Do this reaction to the ultimate
And silica (SiO ₂). These reactions are RO (Si (OR)₂O)_nR + (n + 1) H₂O → n
SiO₂+ (2n + 2) ROH (R represents an alkyl group; n is an integer.)
The amount of silica component remaining based on this reaction formula is
It is converted.

[(C) Organic Acid] The composition of the present invention comprises (C)
An organic acid (hereinafter, referred to as “component (C)”) is blended as an essential component. In the composition of the present invention, by adding the components (B) and (C) in a specific amount to the organic resin (A), aggregates and the like are not generated, mixing stability is good, and sufficient It has a long working time, can secure excellent finish (high gloss value in gloss enamel), has excellent interlayer adhesion, can prevent peeling, blistering, and cracking of the coating film. A coating film having excellent properties can be obtained. The mechanism of action is not clear, but is presumed to be due to the difference in polarity between the components (A), (B) and (C) and the reaction characteristics.

The component (C) is a compound having a carboxyl group, for example, formic acid, acetic acid, propionic acid, lactic acid, butyric acid, butanoic acid, pentanoic acid, hexanoic acid, 2-ethylhexanoic acid, paratoluenesulfonic acid, Chloroacetic acid, dichloroacetic acid, benzoic acid, salicylic acid, oxalic acid,
Examples include malonic acid, maleic acid, adipic acid, azelaic acid, sebacic acid, itaconic acid, citric acid, trimellitic acid, pyromellitic acid, succinic acid, phthalic acid, fumaric acid, and the like, and anhydrides thereof. Of these, acetic acid, propionic acid, lactic acid, oxalic acid, maleic acid, and phthalic acid are particularly preferred.

The mixing ratio of the component (C) is 0.1 to 30 parts by weight, preferably 0.3 to 15 parts by weight, based on 100 parts by weight of the resin solid content of the component (A). By adding the component (C) within such a range, a synergistic effect with the component (B) is exhibited, and the above-described mixing stability, finishability,
A paint excellent in interlayer adhesion and stain resistance can be obtained.

[(D) Amine compound] The coating composition of the present invention can further enhance the interlayer adhesion of the formed coating film by adding the (D) amine compound.
As such amine compounds, water-soluble amines are preferable, and ethylamine, dimethylamine, trimethylamine, triethylamine, diamylamine, ethanolamine, diethanolamine, triethanolamine, cyclohexylamine, aniline, pyridine, morpholine, N-methylmorpholine, Organic amines such as caprolactam, hexamethylenediamine, ethylphenylethanolamine, ethylenediamine, triethylenediamine, aminomethyltriethoxysilane, aminomethyldiethoxysilane, n-trimethoxysilylpropyl-ethylenediamine, γ-phenylaminopropyltrimethoxysilane And aminosilanes such as γ-aminoisobutyltrimethoxysilane and γ-aminopropylmethyldiethoxysilane. .

The mixing ratio of the amine compound (D) is 0.02 to 5.0 parts by weight, preferably 0.05 to 2.0 parts by weight, per 100 parts by weight of the solid content of the component (A). Department.
If the amount of the amine compound is less than 0.02 parts by weight, the effect cannot be obtained, which is not preferable. On the other hand, if it is added in excess of 5.0 parts by weight, the weather resistance of the coating film will be reduced, resulting in lack of practicality.

[(E) Alkoxysilane Compound Containing Polyalkylene Oxide Chain] In the present invention, (E) an alkoxysilane compound containing a polyalkylene oxide chain (hereinafter referred to as “component (E)”) is further added. In addition, it becomes possible to make the coating film surface more hydrophilic than the initial stage, and it is possible to obtain a stain resistance superior to the initial stage. The component (E) is a compound having an alkylene oxide repeating unit and at least one or more alkoxysilyl groups. In the polyalkylene oxide repeating unit of the component (E), the alkylene moiety has 2 to 4 carbon atoms, and the number of repeating units is 2 to 40, preferably 2 to 20.

In such a component (E), both ends of the polyalkylene oxide chain may be alkoxysilyl groups, and one end may be an alkoxysilyl group and the other end may be another functional group. Good. Examples of such a functional group that can be present at one end include a vinyl group,
Examples include a hydroxyl group, an epoxy group, an amino group, an isocyanate group, and a mercapto group. Particularly, the use of a hydroxyl group (hydroxyl group) is preferred. Further, the functional group may be bonded to an alkoxysilyl group via a urethane bond, a urea bond, a siloxane bond, an amide bond, an ether bond, or the like.

As the component (E), for example, those synthesized by reacting a compound containing a polyalkylene oxide chain with a compound containing an alkoxysilyl group (hereinafter, referred to as a coupling agent) can be used.

The polyalkylene oxide chain-containing compound preferably has a weight average molecular weight of 150 to 3500,
200 to 1500 are more preferred. When the weight-average molecular weight is less than 150, the cured film finally obtained is inferior in hydrophilicity, and a cleaning effect of contaminants due to rainfall cannot be obtained. When the weight-average molecular weight exceeds 3500, the water resistance of the cured product and Hardness decreases.

Examples of such polyalkylene oxide chain-containing compounds include polyethylene glycol, polyethylene-propylene glycol, polyethylene-tetramethylene glycol, polyethylene glycol diglycidyl ether, polypropylene glycol diglycidyl ether, polyoxyethylene diglycolic acid, and polyethylene glycol. Examples include vinyl ether, polyethylene glycol divinyl ether, polyethylene glycol allyl ether, and polyethylene glycol diallyl ether. The polyalkylene oxide chain-containing compound can be selected from one kind or a combination of two or more kinds. When two or more types of monomers are used, they may be random copolymers or block copolymers.

On the other hand, the coupling agent is, for example, a compound having at least one or more alkoxysilyl groups and other substituents in one molecule. Specific examples of the coupling agent include β- (3,4 epoxycyclohexyl) ethyltrimethoxysilane, γ-glycidoxypropylmethyldiethoxysilane, γ-glycidoxypropyltriethoxysilane, and N- ( β-aminoethyl) -γ-aminopropylmethyldimethoxysilane, N
-(Β-aminoethyl) -γ-aminopropyltrimethoxysilane, γ-aminopropyltrimethoxysilane,
γ-aminopropyltriethoxysilane, isocyanate-functional silane, γ-methacryloxypropyltrimethoxysilane, γ-methacryloxypropylmethyldiethoxysilane, γ-methacryloxypropyltriethoxysilane, and the like.

The synthesis of the component (E) is not particularly limited, but a polyalkylene oxide chain-containing compound and a coupling agent are separately prepared. For example, for each compound having a polymerizable double bond, a radical polymerization initiator is used. In addition to copolymerization using an amino group, it can be synthesized by a known method such as an addition reaction of an amino group / epoxy group, an isocyanate group / hydroxyl group or an isocyanate group / amino group. It can also be synthesized by a method in which ethylene oxide is ring-opened to an alkoxysilyl compound having an active hydrogen group such as a primary or secondary amino group.

Among these components (E), those having an alkylene oxide chain of an ethylene oxide chain and a hydroxyl group at one end are the most preferred because they have a high anti-staining effect of the present invention, ie, high anti-staining property and permeation resistance. preferable.

The proportion of the component (E) is 0.1 to 20 parts by weight, preferably 0.2 to 10 parts by weight, based on 100 parts by weight of the resin solids of the component (A). If the amount is less than 0.1 part by weight, no effect can be seen.
This results in poor compatibility with the resin and poor water resistance of the cured product.

[Solvent] The coating composition of the present invention uses a non-aqueous solvent as a solvent. Such non-aqueous solvents include, for example, aromatic hydrocarbon solvents such as toluene, xylene, and solvent naphtha, n-hexane, n-hexane and the like.
Pentane, n-octane, n-nonane, n-decane, n
-Undecane, n-dodecane, aliphatic hydrocarbon solvents such as terpin oil and mineral spirit, ethyl acetate, butyl acetate, methyl ethyl ketone, methyl isobutyl ketone, and the like. One or more of these may be used in combination. Can be used.

In the composition of the present invention, it is particularly preferable that at least 50% by weight of the solvent in the coating material is an aliphatic hydrocarbon. This is because the occurrence of a so-called lifting phenomenon of the existing coating film does not occur and the suitability for recoating is excellent. Aliphatic hydrocarbons are also preferred in that they have relatively low toxicity, are high in work safety, and have little effect on air pollution.

[Others] In the coating composition of the present invention, the components (A), (B) and (C) (and (D)
In addition to the transparent (clear) coating film of the component (the component (E) may be added), a coloring pigment may be blended to form a colored (enamel) coating film.
Titanium oxide, zinc oxide, carbon black, ferric oxide (Bengara), lead chromate (molybdate orange),
Inorganic pigments such as graphite, yellow iron oxide, ocher, ultramarine, cobalt green, azo, naphthol, pyrazolone, anthraquinone, perylene, quinacridone,
Organic pigments such as disazo-based, isoindolinone-based, benzimidazole-based, phthalocyanine-based, and quinophthalone-based organic pigments can be used.

It is also possible to use extenders such as heavy calcium carbonate, clay, kaolin, talc, precipitated barium sulfate, barium carbonate, white carbon, and diatomaceous earth. In particular, when a matte coating film is formed, it is optimal to use white carbon or diatomaceous earth which least impairs the stain resistance effect on the coating film surface.
When these inorganic substances are added to the paint, it is preferable to treat the powder surface with a coupling agent or to add the coupling agent to the paint.

In the coating composition of the present invention, it is possible to mix various additives which can be generally added to the coating so as not to affect the effects of the present invention. Such additives include plasticizers, preservatives, fungicides, anti-algal agents, defoamers,
Leveling agents, pigment dispersants, anti-settling agents, anti-sagging agents,
Matting agents, ultraviolet absorbers and the like.

[Applied Surface / Coating Method] The coating composition of the present invention can be used for surface finishing of various materials such as metal, glass, porcelain tile, concrete, siding board, extruded plate and plastic. It is used to protect buildings such as buildings and civil engineering structures. At this time, the coating composition of the present invention is applied to the final finished surface, and can be applied directly to the base material or applied after some surface treatment (base treatment, etc.). Although it is also possible, there is no particular limitation.

The coating composition of the present invention is prepared by adding various additives to form a coating, and then, usually, is diluted with a non-aqueous solvent for coating. As a coating method, for example, various methods such as brush coating, roller coating, spray coating, a roll coater, and a flow coater can be used.

[0074]

EXAMPLES Examples and comparative examples are shown below to further clarify the features of the present invention.

(Synthesis Example 1) Synthesis Example of Alkoxysilane Compound 1 Weight average molecular weight: 500, average condensation degree: about 4, nonvolatile content: 10
To 100% by weight of 0% methyl silicate (hereinafter referred to as "methyl silicate A"), 44.4 parts by weight of n-butyl alcohol and 0.03 part by weight of dibutyltin dilaurate as a catalyst were added, and after mixing, 75 parts by weight were added. The methanol removal reaction was carried out for 8 hours at
Was synthesized. The transesterification rate of this alkoxysilane compound 1 was about 30%, and the residual silica ratio obtained by calcining at 900 ° C. was 40.7% by weight.

(Synthesis Example 2) Synthesis Example of Alkoxysilane Compound 2 Weight average molecular weight: 1000, average degree of condensation: about 8, nonvolatile content: 1
100% by weight of 00% methyl silicate (hereinafter referred to as "methyl silicate B"), 58.0 parts by weight of n-heptyl alcohol, and 0.0% of dibutyltin dilaurate
3 parts by weight were mixed, and an alkoxysilane compound 2 was synthesized in the same manner as in Synthesis Example 1. The transesterification rate of this alkoxysilane compound 2 was about 27%, and the residual silica ratio was 39.4% by weight.

Synthesis Example 3 Synthesis Example of Alkoxysilane Compound Containing Polyalkylene Oxide Chain Polyethylene glycol 200 (average molecular weight: 200; Wako Pure Chemical Industries, Ltd.) was placed in a reaction vessel equipped with a heating device, stirrer, reflux device, dehydration device, and thermometer. 20 parts by weight), 54.3 parts by weight of Y-9030 (manufactured by Nippon Unicar Co., Ltd.), which is an isocyanate-containing silane, and 0.05 part by weight of dibutyltin dilaurate were charged and reacted at 50 ° C. for 8 hours. Thus, a pale yellow polyethylene oxide chain-containing alkoxysilane compound was obtained. The weight average molecular weight of this alkoxysilane compound having a polyethylene oxide chain was 800 as measured by gel permeation chromatography (hereinafter referred to as GPC) in terms of polystyrene.

[0078]

[Table 1]

[0079]

[Table 2]

[0080]

[Table 3]

(Test method)

1. Compatibility Using the resins shown in Table 1 and the raw materials shown in Table 2, the components shown in Table 3 were mixed with the components except for the pigments to prepare coatings. After sufficiently stirring the prepared paint, 15
40μ dry film thickness on a transparent glass plate of 0 × 50 × 3mm
m, spray at a temperature of 20 ° C and humidity of 65
% (Hereinafter referred to as "standard state"), and after 24 hours of dry curing, the transparency of the film was visually evaluated. Evaluation,
As follows. ：: completely transparent state △: slightly opaque state ×: opaque and opaque state

2. Pot life A resin was prepared as shown in Table 1, and a raw material as shown in Table 2 was used to prepare a coating material having the composition shown in Table 3. The prepared paint was put in a container, covered, and allowed to stand in a standard state, and the state after 4 to 8 hours was examined. The evaluation is as follows. ：: No increase in viscosity and no generation of aggregates. ×: A state in which the viscosity has increased or aggregates have been generated.

3. Gloss The paint prepared with the composition shown in Table 3 was 150 × 120 × 3 mm.
An applicator was drawn on a transparent glass plate so that the WET film thickness became 150 μm, and after drying and curing under standard conditions for 72 hours, the glossiness was measured at an angle of 60 degrees according to JIS K5400 (1990) 7.6. did.

4. Interlayer adhesion SK # 100 on a slate plate of 300 × 150 × 3mm
No. 0 primer (epoxy resin-based primer; manufactured by SK Chemical Co., Ltd.) was spray-coated so that the dry coating film thickness was 30 μm, and dried for 16 hours under standard conditions. next,
The paint prepared with the composition shown in Table 3 was dried to a thickness of 25 μm.
It was painted by spraying so that After curing and drying in a standard state for 1 to 7 days, the same paint is further spray-coated thereon so that the dry coating thickness becomes 25 μm, that is, the total coating thickness of the coating becomes 50 μm, It was a test body. The prepared test specimen was cured for 7 days in a standard state, and a grid test (JIS K5400 (19)
90) The adhesion was evaluated in accordance with 8.5.1.
The evaluation is as follows. ：: No defective part ○: Area of defective part is within 5% △: Area of defective part is 5-35% ×: Area of defective part is 35% or more

5. SK # 100 on 150 × 75 × 0.8mm aluminum plate
The No. 0 primer was spray-coated so as to have a dry film thickness of 30 μm, and was dried under standard conditions for 16 hours. Next, the prepared coating composition was spray-coated so as to have a dry film thickness of 40 μm to prepare a test body. The prepared test body was dried and cured in a standard state for 24-168 hours, and then subjected to JIS K5
400 (1990) 8.10 According to the stain resistance test, a 15% by weight aqueous dispersion of carbon black was applied to the coating surface.
The solution was dropped so as to have a diameter of 20 mm and a height of 5 mm, and was allowed to stand in a standard state for 12 hours. Thereafter, the film was washed in running water, and the degree of contamination of the coating film surface was visually evaluated. The evaluation is as follows. ○: No trace △: There is a trace ×: There is a remarkable trace

[0087]

[Table 4]

(Results) Table 4 shows the results of each test. In Examples 1 to 8, which are the compositions of the present invention, excellent results were obtained in all the tests. On the other hand, in Comparative Examples 1 to 3 in which methyl silicate was blended, the results were inferior in the pot life, interlayer adhesion, and stain penetration resistance.

6. Lifting test (Paint P) 100 parts by weight of xylene was further added to the white paint composition formulated in Example 2 to dilute (outside weight 30% by weight)
), And mixed and stirred to produce a spray white paint P. At this time, the content of the aliphatic hydrocarbon in all the solvents was 3
It was 6% by weight. (Paint Q) In addition to the white paint composition of Example 2, LAWS (mineral spirit manufactured by Shell Sekiyu KK)
100 parts by weight were added and diluted (diluted with an outer weight of 30% by weight), mixed and stirred to prepare a white paint Q for spraying. At this time, the content of the aliphatic hydrocarbon in all the solvents was 65% by weight.

(Test Method) A 200 × 300 × 4 mm slate plate was coated with Milk Sealer ES (one-pack epoxy resin sealer; manufactured by SK Kaken Co., Ltd.) at an amount of 0.1 k.
g / m ² , spray-coated to ² g
Dried for hours. Next, the paints P and Q were spray-coated so as to have a coating amount of 0.15 kg / m ² , respectively, and cured and dried under standard conditions for 72 hours. ^The composition was spray-coated so as to obtain a composition No. ^2, and the composition was applied again.

(Results) Observation of the state of the coating film surface at this time revealed that the slate plate sprayed with the paint P had spots on the surface, and a lifting phenomenon was observed. The slate plate sprayed with the paint Q had a good surface condition, and no lifting phenomenon was observed.

[0092]

According to the present invention, no aggregates or the like are generated,
Good mixing stability, sufficient pot life, excellent finish (high gloss value for gloss enamel), excellent interlayer adhesion, and prevents peeling, blistering and cracking of the coating And a coating film having excellent stain resistance can be obtained. Furthermore, by using an amino group-containing resin or by adding an amine compound, interlayer adhesion can be further improved, and by adding a polyalkylene oxide chain-containing alkoxysilane compound, contamination resistance in the initial stage can be improved. Can be improved. Further, in the present invention, when 50% by weight or more of the solvent in the coating material is an aliphatic hydrocarbon, the lifting phenomenon of the coating film at the time of coating, particularly at the time of coating a plurality of times, can be sufficiently prevented.

 ──────────────────────────────────────────────────続 き Continued on the front page F term (reference) 4J038 CD101 CD102 CD112 CE022 CG001 CG042 CG182 DA001 DD001 DD042 DF022 DL022 GA03 GA04 GA05 GA07 GA09 GA11 GA12 GA15 JA21 JA37 JA39 JA41 JA69 JB03 JB04 JB06 JB09 JC30 KA03 LA03 MA06 NA01 PC03

Claims (5)

[Claims] (1) an organic resin, (B) tetraalkoxy
A condensate of silane having an average degree of condensation of 4 to 20;
The alkyl group in the product has 1 to 3 carbon atoms and 4 to 12 carbon atoms.
Are mixed, and the mixing ratio is from 4 to 4 carbon atoms.
12 alkyl groups are 5 to 5 of all alkyl groups in the condensate.
0% of a compound, (C) an organic acid,
(B) component to 100 parts by weight of resin solids
iO ₂1.0 to 50.0 parts by weight in conversion, the component (C)
A coating composition characterized by containing 0.1 to 30 parts by weight.
object. 2. The coating composition according to claim 1, wherein the component (A) is an amino group-containing organic resin. (3) The amine compound (D) is further added in an amount of 0.02 to 5.0 based on 100 parts by weight of the resin solid content of the component (A).
The coating composition according to claim 1, wherein the coating composition is contained in parts by weight. 4. The method according to claim 1, wherein (E) the number of repeating units is 2 to 4.
A polyalkylene oxide chain of 0, an alkoxysilane compound having a weight average molecular weight of 150 to 3500,
The coating composition according to any one of claims 1 to 3, wherein the coating composition is contained in an amount of 0.1 to 20 parts by weight based on 100 parts by weight of the resin solid content of the component (A). 5. The coating composition according to claim 1, wherein at least 50% by weight of the total solvent in the coating is an aliphatic hydrocarbon.