JPH0699139A - Precoat coated plate - Google Patents

Abstract

PURPOSE:To provide a precoat coated plate excellent in pollution resistance, acid resistance, and outdoor weather resistance, and for which lustred finishing can be carried out. CONSTITUTION:A paint consisting of [A] (a) copolymer containing vinyl monomer having alkoxysilane and/or silanol and vinyl monomer having oxy-silane as monomer units or (b) polymer having alkoxysilane and/or silanol and either a compound or a polymer mixture having two or more oxysilane in one molecule and [B] a metal chelate setting agent as a vehicle is applied to and cured on a metal plate with or without an undercoat formed between them and thus a precoat coated metal plate is obtained.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a precoated plate which is excellent in stain resistance, acid resistance and outdoor weather resistance and which can have a high gloss finish.

[0002]

2. Description of the Related Art Conventionally, prepainted coated plates have been widely used for building materials such as roofs and walls of buildings, for processing appliances, and for processing household appliances. In recent years, in the market, when the processed pre-coated plate is used outdoors, it has stain resistance against soot and rain stains, deterioration of the coating film due to acid rain, acid resistance against blistering, long-term weather resistance, Further, when used indoors, stain resistance to foods and oil-based inks is often required.

In recent years, polyvinylidene fluoride as a resin component has been used as a pre-coated plate having excellent outdoor durability of 70 to 70%.
A coated plate coated with a fluororesin-based paint containing about 80% is used. However, the above-mentioned fluororesin-based paint coated plate has a low gloss, and a high gloss finish cannot be obtained, and the 60 ° specular reflectance (60 ° gloss) is usually 30 to
It is about 50%. Further, the fluororesin-based paint coating film is generally a thermoplastic coating film, and the elastic modulus of the coating film is likely to largely decrease with increasing temperature, and is easily soiled. Further, as a baking condition for obtaining a coating film, there is a problem that a baking time of about 40 to 70 seconds is required and energy consumption is large under the condition that the maximum temperature reached by the material is 230 ° C. or higher.

Therefore, the present inventors have found that the stain resistance, the acid resistance, and the
We have conducted an earnest study to obtain a pre-coated plate that has excellent outdoor weather resistance, can be finished with a high gloss, and has a coating film that is hardened even by baking at a maximum material temperature of 180 ° C or less for 60 seconds or less. As a result, they have found that a pre-coated plate capable of solving the above problems can be obtained, and completed the present invention.

[0005]

That is, the present invention provides a vinyl monomer containing an alkoxysilane group and / or a silanol group and a vinyl monomer containing an oxirane group on a metal plate with or without an undercoat coating film. A precoat coated plate formed by forming a cured coating film of a coating composition containing a copolymer containing a monomer as a monomer component and a metal chelate curing agent as a vehicle component (hereinafter referred to as "first precoat coated plate"). May be abbreviated as ".").

The present invention further relates to a polymer containing an alkoxysilane group and / or a silanol group on a metal plate with or without an undercoat coating film, and a compound or polymer having two or more oxirane groups in one molecule. , And a pre-coated coated plate formed by forming a cured coating film of a coating material containing a metal chelate curing agent as a vehicle component (hereinafter, may be abbreviated as “second pre-coated coated plate”). .

[0007] In the first pre-coated plate, a paint for obtaining a cured coating film formed on a metal plate with or without an undercoat film (hereinafter referred to as "first top-coat paint"). Is abbreviated.) Is an alkoxysilane group and / or silanol group (hereinafter, these groups may be simply abbreviated as “reactive silane group”)-containing vinyl monomer and oxirane group-containing vinyl monomer. It is a coating composition containing a copolymer (hereinafter, abbreviated as "copolymer A") containing a polymer as a monomer component and a metal chelate curing agent as a vehicle component.

The reactive silane group-containing vinyl monomer used in the copolymer A is a compound containing a polymerizable unsaturated bond and at least one silanol group or alkoxysilane group in one molecule, or It is a siloxane-based macromonomer.

Examples of the compound containing a polymerizable unsaturated bond and at least one reactive silane group include compounds represented by the following general formula [1] (hereinafter, abbreviated as "compound (a)"). be able to.

[0010]

[Chemical 4]

[In the formula, A is —C (O) O— or a phenylene group, R ₁ is a hydrogen atom or a methyl group, R ₂ is an aliphatic hydrocarbon group having 1 to 6 carbon atoms, and R ₃ is Identical or different, phenyl group, C1-6 alkyl group, C1
To 6 are alkoxyl groups or hydroxyl groups, R ₄ is a hydrogen atom or an alkyl group having 1 to 6 carbon atoms, and n is an integer of 1 to 20. ].

In the general formula [1], the aliphatic saturated hydrocarbon group having 1 to 6 carbon atoms represented by R ₂ is a linear or branched alkylene group such as methylene, ethylene, propylene, tetramethylene and ethyl. Examples thereof include ethylene, pentamethylene and hexamethylene groups. Examples of the alkyl group having 1 to 6 carbon atoms represented by R ₃ and R ₄ include linear or branched alkyl groups such as methyl,
Examples thereof include ethyl, n-propyl, isopropyl, n-butyl, isobutyl, sec-butyl, tert-butyl, n-pentyl, isopentyl, neopentyl, n-hexyl and isohexyl groups. As the alkoxy group having 1 to 6 carbon atoms represented by R ₃ , a linear or branched alkoxy group such as methoxy, ethoxy, n-propoxy, isopropoxy, n-butoxy, isobutoxy,
Examples thereof include sec-butoxy, tert-butoxy, n-pentoxy, isopentoxy, n-hexyloxy and isohexyloxy groups.

Among the compounds (a) represented by the general formula [1], A
The following compounds can be given as examples of a compound represented by -C (O) O-. γ- (meth) acryloxypropyltrimethoxysilane, γ- (meth) acryloxypropyltriethoxysilane, γ- (meth) acryloxypropyltripropoxysilane, γ- (meth) acryloxypropylmethyldimethoxysilane, γ- (Meth) acryloxypropylmethyldiethoxysilane, γ
-(Meth) acryloxypropylmethyldipropoxysilane, γ- (meth) acryloxybutylphenyldimethoxysilane, γ- (meth) acryloxybutylphenyldiethoxysilane, γ- (meth) acryloxybutylphenyldipropoxysilane, γ- (meth) acryloxypropyldimethylmethoxysilane, γ- (meth) acryloxypropyldimethylethoxysilane, γ- (meth)
Acryloxypropylphenylmethylmethoxysilane,
γ- (meth) acryloxypropylphenylmethylethoxysilane, γ- (meth) acryloxypropyltrisilanol,

[0014]

[Chemical 5]

Further, among the compounds (a) of the general formula (1),
Examples of the compound in which A is a phenylene group include the following compounds.

[0016]

[Chemical 6]

As the siloxane-based macromer, the compound (a) represented by the general formula [1] is reacted with the compound represented by the general formula [2] (hereinafter abbreviated as compound (b)). The thing obtained by this can be mentioned.

[0018]

[Chemical 7]

[In the formula, R ₅ represents an aliphatic hydrocarbon group having 1 to 8 carbon atoms or a phenyl group, and R ₆ is the same or different and represents a hydroxyl group or an alkoxyl group having 1 to 4 carbon atoms. ]

In the general formula [2], the aliphatic hydrocarbon group having 1 to 8 carbon atoms represented by R ₅ is the above R
Besides the group represented by ₂ , for example, a heptyl group, an octyl group and the like can be mentioned. Examples of the alkoxyl group having 1 to 4 carbon atoms represented by R ₆ include linear or branched alkoxyl groups such as methoxy, ethoxy, n-propoxy, isopropoxy, n-butoxy, isobutoxy, sec-butoxy and tert-butoxy. A group etc. can be mentioned. In the general formula [2], R ₅ is particularly preferably a methyl group or a phenyl group. R ₆ is particularly preferably a methoxy group, an ethoxy group, a propoxy group, a butoxy group or a hydroxyl group.

Specific preferred examples of the compound (b) include:
Examples thereof include methyltrimethoxysilane, phenyltrimethoxysilane, butyltrimethoxysilane, methyltriethoxysilane, methyltributoxysilane, phenyltrisilanol and methyltrisilanol.
Of these, methyltrimethoxysilane, phenyltrimethoxysilane, phenyltrisilanol and the like are particularly preferably used. The compound (b) can be used alone or in combination.

The reaction between the compound (a) and the compound (b) is
It is carried out by dehydration condensation of the hydroxyl group contained in both compounds or the hydroxyl group generated by hydrolysis of the alkoxyl group. At this time, not only dehydration condensation but also partial dealcoholization condensation occurs depending on the reaction conditions.

This reaction can be carried out without solvent, but is preferably carried out using an organic solvent capable of dissolving the compound (a) and the compound (b), or water as a solvent. When used in a solution state, the total concentration of the compound (a) and the compound (b) is preferably about 5% by weight or more.

In the reaction between the compound (a) and the compound (b), the reaction temperature is usually about 20 to 180 ° C., and preferably about 50 to 120 ° C. The reaction time is usually about 1 to 40 hours.
Further, in this reaction, a polymerization inhibitor may be added if necessary. The polymerization inhibitor is effective for preventing the unsaturated bond contained in the compound (a) from polymerizing during the reaction with the compound (b), and specifically, for example, hydroquinone or hydroquinone monomethyl ether is used. it can.

Further, the compound (a) and the compound (b) are
When it has an alkoxyl group bonded to Si, it is preferably hydrolyzed prior to the condensation, and the hydrolysis reaction and the condensation reaction can be continuously carried out by heating and stirring in the presence of water and a catalyst.

The amount of water used in this case is not particularly limited, but is preferably about 0.1 mol or more per mol of the alkoxyl group. If the amount is less than about 0.1 mol, the reaction of both compounds may decrease. The most preferable method is to use water as a solvent in a large excess. Also,
In this reaction, if water and a water-soluble organic solvent are used in combination, the reaction system can be homogenized when a sparingly water-soluble alcohol is produced by condensation. As the water-soluble organic solvent, alcohol-based, ester-based, ether-based, and ketone-based solvents can be preferably used.

As the catalyst of this hydrolysis reaction, an acid catalyst or an alkali catalyst can be used, and specifically, as the acid catalyst, hydrochloric acid, sulfuric acid, phosphoric acid, formic acid, acetic acid, propionic acid, acrylic acid, methacrylic acid or the like can be used. Sodium hydroxide, triethylamine, ammonia, etc. can be used as the alkali catalyst. The amount of the catalyst added is the above compound (a)
With respect to the total amount of the compound (b) and the compound (b), a range of about 0.0001 to 5% by weight, preferably about 0.01 to 0.1% by weight is suitable.

The siloxane-based macromonomer thus obtained has a long-chain structure having a polymerizable unsaturated bond, a siloxane bond and an alkoxysilane group in the molecule, a ladder structure or a mixture thereof. Among these siloxane-based macromonomers, an average of 0.2 to 1.9, preferably 0.6 to 1.4, polymerizable unsaturated bonds, an average of 2 in one molecule.
Having a number average molecular weight of about 400 to 100,000 in which at least one alkoxy group and the main skeleton are composed of siloxane bonds
It is preferable to use a polysiloxane macromonomer in the range of 0, preferably about 1,000 to 20,000 because a cured coating film having excellent mechanical strength (especially elongation), weather resistance and stain resistance can be formed.

The polysiloxane-based macromonomer contains the compound (a) and the compound (b) in an amount of 70 to 99.999 mol%, preferably 90 to 99.9 mol% based on the total amount of the both compounds. Mol%, more preferably 95-
99 mol%, the compound (a) is 30 to 0.001 mol%,
Preferably 10 to 0.1 mol%, more preferably 5 to 1
It is within the range of mol%. If the amount of the compound (b) is less than 70 mol%, gelation is likely to occur in the copolymerization reaction, while 99.9.
If it exceeds 99 mol%, the amount of polysiloxane that does not copolymerize increases and the resin liquid becomes turbid, resulting in mechanical strength,
It is not preferable because a cured coating film excellent in gloss and smoothness cannot be formed.

The oxirane group-containing vinyl monomer used in the copolymer A has one or more oxirane groups and one polymerizable unsaturated bond in one molecule.
Examples of the oxirane group-containing vinyl monomer include alicyclic oxirane group-containing vinyl monomers represented by the following general formulas.

[0031]

[Chemical 8]

[0032]

[Chemical 9]

[0033]

[Chemical 10]

[0034]

[Chemical 11]

[In each general formula, R ₇ represents a hydrogen atom or a methyl group. R ₈ represents a divalent aliphatic saturated hydrocarbon group having 1 to 6 carbon atoms. R ₉ represents a divalent hydrocarbon group having 1 to 10 carbon atoms. l shows the integer of 0-20. ]

In the above, the divalent aliphatic saturated hydrocarbon group having 1 to 6 carbon atoms represented by R ₈ is a linear or branched alkylene group such as methylene, ethylene,
Examples thereof include propylene, tetramethylene, ethylethylene, pentamethylene and hexamethylene groups.
Examples of the divalent hydrocarbon group having 1 to 10 carbon atoms represented by R ₉ include methylene, ethylene, propylene, tetramethylene, ethylethylene, pentamethylene, hexamethylene, polymethylene, phenylene, cyclohexylene and xylylene groups. Etc. can be mentioned.

Typical examples of oxirane group-containing vinyl monomers other than alicyclic groups include those represented by the following general formula.

[0038]

[Chemical 12]

[In the formula, R ₇ and R ₈ are the same as defined above. ]

Among the above-mentioned oxirane group-containing vinyl monomers, it is particularly preferable to use alicyclic oxirane group-containing vinyl monomers from the viewpoint of curability and the like. That is, when the alicyclic oxirane group-containing vinyl monomer is used, since the reactivity of the ring-opening polymerization reaction of the oxirane group is high, it is possible to obtain the effect that the curing is quick and the physical properties of the cured coating film are further improved. .

The copolymer A is a vinyl copolymer using the above-mentioned reactive silane group-containing vinyl monomer and oxirane group-containing vinyl monomer as monomer components. In the copolymer A, in addition to the above-mentioned monomer components, other polymerizable vinyl monomer (hereinafter, may be abbreviated as “monomer (c)”) may be used in a unit amount, if necessary. It can also be used as a body component.

The above-mentioned monomer (c) can be widely selected depending on the desired performance. Typical examples of such unsaturated monomers are as follows.

(A) Ester of acrylic acid or methacrylic acid: For example, methyl acrylate, ethyl acrylate,
Propyl acrylate, isopropyl acrylate, butyl acrylate, hexyl acrylate, octyl acrylate, lauryl acrylate, methyl methacrylate, ethyl methacrylate, propyl methacrylate, isopropyl methacrylate, butyl methacrylate, hexyl methacrylate, methacrylic acid C1 to C18 alkyl esters of acrylic acid or methacrylic acid such as octyl and lauryl methacrylate; methoxybutyl acrylate, methoxybutyl methacrylate, methoxyethyl acrylate, methoxyethyl methacrylate, ethoxybutyl acrylate, ethoxy methacrylate. C2-C18 alkoxyalkyl ester of acrylic acid or methacrylic acid such as butyl; acrylic acid or methacrylic acid such as allyl acrylate and allyl methacrylate C2-C8 alkenyl ester; C2-C8 hydroxyalkyl ester of acrylic acid or methacrylic acid such as hydroxyethyl acrylate, hydroxyethyl methacrylate, hydroxypropyl acrylate and hydroxypropyl methacrylate; hydroxyethyl acrylate and hydroxyethyl methacrylate Of acrylic acid or methacrylic acid having 1 to 4 carbon atoms and an adduct of 1 to 10 moles of ε-caprolactone; acrylic acid or methacrylic acid having 3 carbon atoms such as allyloxyethyl acrylate and allyloxymethacrylate. ~ 18 alkenyloxyalkyl esters.

(B) Vinyl aromatic compound: For example, styrene, α-methylstyrene, vinyltoluene, p-chlorostyrene. (C) Polyolefin compound: For example, butadiene, isoprene, chloroprene. (D) Others: acrylonitrile, methacrylonitrile, methyl isopropenyl ketone, vinyl acetate beopa monomer (shell chemical product), vinyl propionate, vinyl pivalate, etc.

The amount of each monomer used in the copolymer A is
It is within the following range. Vinyl monomer containing reactive silane group
0.01 to 98% by weight, preferably 0.1 to 60% by weight, oxirane group-containing vinyl monomer 1 to 99.9% by weight, preferably 3 to 60% by weight, monomer (c) 0 to 9
8.99% by weight, preferably 10-96.9% by weight

When the amount of the reactive silane group-containing vinyl monomer used is less than this range, the mechanical strength, stain resistance and weather resistance of the coating film tend to deteriorate, and when it exceeds this range, the mechanical strength is increased. However, a coating film having an inferior appearance is formed, which is not preferable. If the amount of the oxirane group-containing vinyl monomer used is less than this range, the curability decreases, and if it exceeds this range, the mechanical strength, stain resistance, and weather resistance of the coating film tend to decrease.

The above copolymer A can be easily polymerized by a conventionally known radical polymerization method in a solution. The copolymer A has a number average molecular weight of 3,000 to 20.
Approximately 10,000, preferably 10,000 to 8
It is more preferably about 10,000.

A coating material for obtaining a cured coating film formed on the metal plate of the second precoat coated plate with or without an undercoat coating film (hereinafter, referred to as "second top coating composition"). May be abbreviated as "." Is a reactive silane group-containing polymer (hereinafter abbreviated as "polymer B"), a compound or polymer having two or more oxirane groups in one molecule (hereinafter "oxirane C"). And a metal chelate curing agent as a vehicle component.

The polymer B used in the above second top coating composition comprises two or more alkoxysilane groups and // in one molecule.
Alternatively, it is a polymer containing a silanol group, and the reactive silane group-containing vinyl monomer used in the copolymer A is used as an essential monomer component, and the monomer (c) is used in a single amount if necessary. A homopolymer or a copolymer as a body component (hereinafter,
It is abbreviated as "polymer (I)". Or a polysiloxane (hereinafter abbreviated as “polysiloxane (II)”) obtained by reacting a compound represented by the following general formula [3] (hereinafter abbreviated as “compound (d)”). Can be

[0050]

[Chemical 13]

[Wherein R ₆ has the same meaning as described above and R _6
7 represents an aliphatic hydrocarbon group having 1 to 8 carbon atoms, a phenyl group or a 3,4-epoxycyclohexylalkyl group having 7 to 10 carbon atoms. ]

The amount of each monomer used in the polymer (I) is in the following range. Reactive silane group-containing vinyl monomer 0.5 to 100% by weight, preferably 3 to 70% by weight, monomer (c) 0 to 99.5% by weight, preferably 3
0 to 97% by weight.

Polymerization of the polymer (I) can be easily carried out by a conventionally known radical polymerization method in a solution. The polymer (I) has a number average molecular weight of 1,000 to 20.
Approximately 10,000, preferably 2,000-30,
Those of about 000 are more preferable.

To obtain the polysiloxane (II),
The compound (d) represented by the general formula [3] includes the compound (b), and specific examples thereof include those exemplified as the compound (b). Specific examples of the compound (d) include 3,4-epoxycyclohexylmethyltrimethoxysilane and 3,4-epoxycyclohexylethyltrimethoxysilane.

The method for obtaining the polysiloxane (II) by reacting the compound (d) is as follows.
It is possible to use the same method as the method of obtaining a polysiloxane macromonomer by reacting with. The main skeleton of polysiloxane (II) obtained by subjecting compound (d) to a reaction such as a condensation reaction is composed of siloxane bonds, and the structure of the main skeleton is mainly long-chain (linear) or ladder-shaped (ladder). It is preferable to use a resin or a mixed system thereof or a mixed system having a large number of ladder portions from the viewpoint of water resistance, heat resistance, light resistance and the like. These structures can be arbitrarily selected depending on the blending amount of water, acid catalyst, and the like. The polysiloxane (II) has at least two Si-bonded hydroxyl groups and / or alkoxy groups having 1 to 4 carbon atoms per molecule and has a number average molecular weight of about 1,000 to 200,000. Is preferred,
It is more preferably about 2,000 to 30,000.

The oxirane C is a compound or polymer having two or more oxirane groups in one molecule, and the oxirane group is preferably an alicyclic oxirane group. Examples of the oxirane C include compounds represented by the following general formula

[0057]

[Chemical 14]

Addition product of a compound represented by the above general formula with a polybasic acid; Addition product of 3,4-epoxycyclohexylmethanol and the following polyisocyanate compound (Examples of usable polyisocyanate compounds include hexamethylene Aliphatic diisocyanates such as diisocyanate or trimethylhexamethylene diisocyanate; cycloaliphatic diisocyanates such as xylylene diisocyanate or isophorone diisocyanate; organic diisocyanates themselves such as aromatic diisocyanates such as tolylene diisocyanate or 4,4'-diphenylmethane diisocyanate Or an adduct of each of these organic diisocyanates with a polyhydric alcohol, a low molecular weight polyester resin or water, or as described above. Examples include polymers of organic diisocyanates, isocyanates, biurets, etc.); polybasic acids having a tetrahydrophenylene group such as tetrahydrophthalic anhydride, and polyvalents such as trimethylolpropane and 1,4-butanediol. A product obtained by oxidizing an esterification product with alcohol with peracetic acid or the like; an oxirane group-containing vinyl monomer used in the copolymer A as an essential monomer component, and if necessary, the monomer ( A homopolymer or a copolymer (hereinafter abbreviated as "polymer (III)") containing c) as a monomer component can be used.

The amount of each monomer used in the polymer (III) is in the following range. Oxirane group-containing vinyl monomer 3 to 100% by weight, preferably 20 to 100% by weight,
Monomer (c) 0 to 97% by weight, preferably 0 to 80% by weight.

The polymer (III) can be easily produced by a conventionally known polymerization method such as a radical polymerization method in an organic solvent. The polymer (III) has a number average molecular weight of 3,
000 to 200,000 is preferable, and 10,
Those of about 000 to 80,000 are more preferable.

In the second top coating composition, the blending ratio of the polymer B and the oxirane C is generally in the range of 5 to 95% by weight of the polymer B and 95 to 5% by weight of the oxirane C based on the total amount of both.

The metal chelate curing agent compounded as a vehicle component in both the first top coating composition and the second top coating composition used in the present invention is the same as the alkoxysilane group and / or silanol group in the other vehicle component. It promotes the curing reaction based on the oxirane group. Examples of the metal chelate curing agent include aluminum chelate compounds, titanium chelate compounds, zirconium chelate compounds, vanadium chelate compounds, iron chelate compounds, and the like.

Of these, aluminum chelate compounds, titanium chelate compounds and zirconium chelate compounds are preferable. Further, among these chelate compounds, a chelate compound containing a compound capable of forming a keto-enol tautomer as a ligand forming a stable chelate ring is preferable.

Examples of the compound capable of forming the keto / enol tautomer include β-diketones (acetylacetone and the like), acetoacetic acid esters (methyl acetoacetate and the like),
Malonic acid esters (ethyl malonate, etc.), ketones having a hydroxyl group at the β-position (diacetone alcohol, etc.), aldehydes having a hydroxyl group at the β-position (salicylaldehyde, etc.), esters having a hydroxyl group at the β-position ( Methyl salicylate) or the like can be used. Particularly, preferable results are obtained by using acetoacetic acid esters and β-diketones.

The aluminum chelate compound, titanium chelate compound and zirconium chelate compound will be described. The aluminum chelate compound has, for example, the following general formula:

[0066]

[Chemical 15]

[In the formula, R ₁₀ represents an alkyl group or an alkenyl group having 1 to 20 carbon atoms. ] The compound capable of forming the keto / enol tautomer is usually mixed in a molar ratio of about 3 mol or less to 1 mol of an aluminum alcoholate represented by the following formula, and it is suitably prepared by heating if necessary. be able to.

C 1-20, which is R ₁₀ in the general formula [4]
Examples of the alkyl group include, in addition to the alkyl group having 1 to 6 carbon atoms, heptyl, octyl, nonyl, decyl, undecyl, dodecyl, tridecyl, tetradecyl, octadecyl group, etc., and the alkenyl group includes vinyl, allyl group, etc. Can be illustrated respectively.

The aluminum alcoholates represented by the general formula [4] include aluminum trimethoxide,
Aluminum triethoxide, aluminum tri-n-
Propoxide, aluminum triisopropoxide, aluminum tri-n-butoxide, aluminum triisobutoxide, aluminum tri-sec-butoxide,
Aluminum tri-tert-butoxide and the like, particularly aluminum triisopropoxide, aluminum tri-
It is preferable to use sec-butoxide, aluminum tri-n-butoxide and the like.

The titanium chelate compound is, for example, one of the following general formulas:

[0071]

[Chemical 16]

[In the formula, m is an integer of 0 to ₁₀ and R ₁₀ has the same meaning as described above. ] In the titanates represented by
The compound capable of forming the keto-enol tautomer is mixed with i1 mol in a molar ratio of usually about 4 mol or less,
It can be suitably prepared by heating if necessary.

Typical examples of the titanates represented by the general formula [5] include tetraisopropyl titanate, tetra-n-butyl titanate, tetraisobutyl titanate, tetra-t-butyl titanate, and dimers of these titanates. To 11-mer.

The zirconium chelate compound has, for example, the following general formula:

[0075]

[Chemical 17]

[In the formula, m and R ₁₀ have the same meanings as described above. ] It is preferably prepared by mixing 1 mol of Zr in the zirconates represented by the above with the compound capable of forming the keto-enol tautomer in a molar ratio of usually about 4 mol or less, and heating if necessary. can do.

Typical examples of the zirconates represented by the general formula [6] include tetraisopropyl zirconate,
Tetra-n-propyl zirconate, tetraisobutyl zirconate, tetra-n-butyl zirconate, tetra-sec-butyl zirconate, tetra-tert-butyl zirconate, and dimers to dimers of these zirconates And so on.

Particularly preferable examples of the above metal chelate curing agent include diisopropylate ethylacetoacetate aluminum, tris (ethylacetoacetate) aluminum, tris (n-propylacetoacetate) aluminum, tris (isopropylacetoacetate) aluminum, tris (n). -Butylacetoacetate) aluminum, isopropoxybis (ethylacetoacetate) aluminum, diisopropoxyethylacetoacetate aluminum, tris (acetylacetonato)
Aluminum, tris (ethylacetonato) aluminum, diisopropylate ethylacetonato aluminum, monoacetylacetonato bis (ethylacetonato) aluminum, monoethylacetoacetate bis (acetylacetonato) aluminum, tris (isopropylate) aluminum, Aluminum chelate compounds such as tri (sec-butyrate) aluminum and diisopropylate mono-sec-butoxy aluminum;

Titanium chelate compounds such as diisopropoxy bis (ethylacetoacetate) titanate, diisopropoxy bis (acetylacetate) titanate and diisopropoxy bis (acetylacetonato) titanate;

Tetrakis (n-propylacetoacetate) zirconium, tetrakis (acetylacetonato)
Zirconium, tetrakis (ethyl acetoacetate)
Examples thereof include zirconium chelate compounds such as zirconium.

As the metal chelate curing agent, one kind may be used, or two or more kinds may be appropriately used in combination. The compounding amount of the metal chelate curing agent is 100 parts by weight of the copolymer A in the first top coating composition, and 100 parts by weight of the total amount of the polymer B and oxirane C in the second top coating composition. It is suitable that the amount is about 0.01 to 30 parts by weight, respectively.

Each of the first top coating composition and the second top coating composition used in the present invention, if necessary,
An extender pigment, a coloring pigment, a dye or the like can be added.
In addition, if necessary, a monofunctional or polyfunctional epoxy compound, a low molecular weight silane compound such as triphenylmethoxysilane, diphenyldimethoxysilane, or the like, a silicone resin having a general alkoxysilane group, a hydroxyl group-containing acrylic Resin etc. can also be added.

The above-mentioned hydroxyl group-containing acrylic resin is a polysiloxane (I
When I) is used, it is effective to improve the mechanical properties of the coating film. The hydroxyl group-containing acrylic resin contains the monomer (c) as a monomer component and usually has a hydroxyl value of 50 to 50.
It can be easily produced by a conventionally known polymerization method such as a radical polymerization method in an organic solvent using a hydroxyl group-containing monomer as an essential monomer component so as to be in the range of 400 mgKOH / g resin. The hydroxyl group-containing acrylic resin preferably has a number average molecular weight of about 2,000 to 100,000, more preferably about 5,000 to 40,000.

In the precoated coated plate of the present invention, as the metal plate, a cold rolled steel plate, a hot dip galvanized steel plate, an electrogalvanized steel plate, an alloy plated steel plate of zinc-aluminum, iron-zinc, nickel-zinc or the like, an aluminum plate, an aluminum plate. Examples thereof include plated steel plate, stainless steel plate, copper plate, copper-plated steel plate and tin-plated steel plate. Further, the metal plate in the present invention includes those obtained by subjecting the surface of these metal plates to a known metal surface treatment such as phosphate treatment or chromate treatment in order to improve the adhesion to a coating film and the corrosion resistance.

The coated plate of the present invention has a coating film of the first topcoat paint or the second topcoat paint formed on the metal plate with or without an undercoat film. Is.

The above-mentioned undercoating film is provided for the purpose of improving the adhesion between the metal plate and the topcoating paint film, improving the corrosion resistance, and the like. In some cases, it is aimed at improving the sex. As the undercoat paint used for forming the undercoat coating film, epoxy resin system, epoxy modified polyester resin system, acrylic-aminoplast resin system, acrylic-urethane resin system, polyester resin system, polyvinyl chloride system, vinyl acetate-vinyl chloride A paint such as a copolymer system is used. The undercoat paint may contain an extender pigment, a rust preventive pigment, a coloring pigment, and other paint additives which are usually used in paints. The thickness of the undercoat coating film is not particularly limited, but is usually 30 μm or less, preferably about 2 to 10 μm.

The first top coating composition or the second top coating composition can be easily crosslinked and cured in the presence of water at a low temperature of 100 ° C. or lower. Water can be applied to the coating composition after the application, or the composition can be exposed to the air after the application, and can be sufficiently cured in about 8 hours to 7 days without any heating. Further, for example, when heated to 40 to 100 ° C., 5
It can be sufficiently cured in about 3 minutes to 3 hours. Also, a small amount of water, such as moisture in the air, is sufficient for the moisture required for curing. If water is added before coating, it is usually 0.1
An addition amount of about 1% by weight is sufficient.

The reason why the top coating composition is easily crosslinked and cured at a low temperature in the presence of a small amount of water is considered as follows. Taking the case of using an organoaluminum chelate compound as a metal chelate curing agent, as a first step reaction, an alkoxy group is hydrolyzed in the presence of water using the aluminum chelate compound as a catalyst to produce a silanol group. Next, as a second step reaction, crosslinking occurs by dehydration condensation of silanol groups or by reacting with an aluminum chelate compound to form the following bond.

[0089]

[Chemical 18]

Further, as a reaction in the third step, the bond is coordinated to another silanol group to polarize the silanol group, and the polarized silanol group causes ring-opening polymerization of the oxirane group to cause crosslinking. Since the second-step reaction and the third-step reaction occur in a chain parallel manner and are crosslinked and hardened, they can be hardened even at a low temperature with a small amount of water.

The coating of the top coating composition is usually carried out by adjusting the viscosity of the coating composition with a diluting solvent and then applying a coating method such as spraying, roll coating, curtain flow coating, dip coating, flow coating or brush coating to a dry film thickness of about 2 ~ 100μ, preferably 10
It can be carried out by applying 50 μm and drying. Drying is usually performed at room temperature for 8 hours to 7 days for about 40 minutes.
Approximately 5 minutes to 3 hours when heated to -100 ° C, approximately 130 to 20
The heating at 0 ° C can be performed for 15 to 60 seconds, whereby a cured coating film can be obtained.

[0092]

The precoated plate of the present invention has a cured coating film based on the reaction of an alkoxysilane group and / or a silanol group, an oxirane group and a metal chelate curing agent as a top coating cured coating film, and therefore has a stain resistant property. It has excellent properties, acid resistance, and outdoor durability, and is capable of high gloss finish. Also, this coated plate has a topcoat baking condition of 200 ° C.
It can be obtained even at a baking temperature of 60 seconds or less at the following material reaching temperature.

[0093]

EXAMPLES The present invention will be described in more detail below with reference to examples. Hereinafter, "parts" and "%" are based on weight unless otherwise specified.

Synthesis Example of Polysiloxane Macromonomer Synthesis Example 1 Methyltrimethoxysilane 2,720 g (20 mol) γ-methacryloyloxypropyltrimethoxysilane 256 g (1 mol) deionized water 1,134 g 60% hydrochloric acid 2 g Hydroquinone 1 g The mixture was reacted at 80 ° C. for 5 hours. The number average molecular weight of the obtained polysiloxane macromonomer is 2,
000, on average, had 1 vinyl group (polymerizable unsaturated bond) and 4 hydroxyl groups per molecule.

Synthesis Example 2 Phenyltrisilanol 7,800 g (50 mol) γ-acryloxypropyltrisilanol 200 g (1 mol) Toluene 4,500 g These mixtures were reacted at 117 ° C. for 3 hours for dehydration. The obtained polysiloxane macromonomer had a number average molecular weight of 7,000, and had one vinyl group and 5 to 10 hydroxyl groups per molecule on average.

Synthetic Example of Copolymer A Synthetic Example 3 The following mixture was added dropwise to a mixed solvent of 70 parts of xylene and 15 parts of isobutyl acetate heated to 120 ° C., polymerized, and 15 parts of isobutanol was added to give a solid. A 50% transparent copolymer A1 solution was obtained. The number average molecular weight of this product was about 20,000. Macromonomer obtained in Synthesis Example 1 10 parts 3,4-epoxycyclohexylmethyl methacrylate 20 parts n-butyl methacrylate 20 parts 2-ethylhexyl methacrylate 30 parts FM-3X monomer (Note 1) 20 parts 2,2'-azobisiso Butyronitrile 2 parts (Note 1): Ring-opening polymer of ε-caprolactone having a polymerizable unsaturated group and a hydroxyl group, manufactured by Daicel Chemical Industries, Ltd.

Synthesis Example 4 The following mixture was added dropwise to a mixed solvent of 70 parts of xylene and 15 parts of isobutyl acetate heated to 120 ° C., polymerized, 15 parts of isobutanol was added, and a transparent copolymer having a solid content of 50% was added. A combined A2 solution was obtained. The number average molecular weight of this product was about 40,000. Macromonomer obtained in Synthesis Example 10 10 parts 2-hydroxyethyl acrylate 10 parts 3,4-epoxycyclohexylmethyl methacrylate 20 parts 2-ethylhexyl methacrylate 60 parts 2,2'-azobisisobutyronitrile 1 part

Synthesis Example 5 The following mixture was added dropwise to a mixed solvent of 70 parts of xylene and 15 parts of isobutyl acetate heated to 120 ° C., and the mixture was polymerized.
15 parts of isobutanol was added to obtain a transparent copolymer A3 solution having a solid content of 50%. The number average molecular weight of the obtained copolymer was about 10,000. γ-methacryloyloxypropyltrimethoxysilane 10 parts 3,4-epoxycyclohexylmethyl methacrylate 20 parts n-butyl methacrylate 20 parts 2-ethylhexyl methacrylate 30 parts FM-3X monomer 20 parts 2,2′-azobisisobutyronitrile 4 Department

Synthesis Example of Polymer B Synthesis Example 6 Macromonomer obtained in Synthesis Example 1 30 parts 2-Ethylhexyl Methacrylate 45 parts n-Butyl Methacrylate 20 parts 2-Hydroxyethyl Methacrylate 5 parts 2,2'-Azobisisobutyi Ronitrile 2 parts The above mixture was added dropwise to a mixed solvent of 70 parts of xylene and 15 parts of isobutyl acetate heated at 120 ° C., and the mixture was polymerized.
15 parts of isobutanol was added to obtain a transparent polymer B1 solution having a solid content of 50%. The number average molecular weight of this polymer was about 20,000.

Synthesis Example 7 Macromonomer obtained in Synthesis Example 2 10 parts 2-hydroxyethyl acrylate 10 parts n-butyl methacrylate 20 parts 2-ethylhexyl methacrylate 60 parts 2,2'-azobisisobutyronitrile 1 part The mixture was added dropwise to a mixed solvent of 70 parts of xylene and 15 parts of isobutyl acetate heated to 120 ° C., and the mixture was polymerized.
15 parts of isobutanol was added to obtain a transparent polymer B2 solution having a solid content of 50%. The number average molecular weight of this polymer was about 40,000.

Synthesis Example 8 Phenyltrisilanol 780 g (5 mol) 3,4-epoxycyclohexylethyltrisilanol 204 g (1 mol) Toluene 850 g The above mixture was reacted at 117 ° C. for 3 hours for dehydration to obtain a polymer B3 solution. The obtained polymer B3, polysiloxane, had a number average molecular weight of about 20,000 and had an average of 20 epoxy groups and 4 hydroxyl groups per molecule.

Synthesis Example 9 Phenyltrisilanol 156 parts Toluene 130 parts The above mixture was reacted at 117 ° C. for 3 hours and dehydrated to obtain a polymer B4 liquid. The number average molecular weight of the obtained polymer B4, polysiloxane, was about 20,000, and it had 4 hydroxyl groups per molecule on average.

Synthesis Example of Oxirane C Synthesis Example 10 3,4-Epoxycyclohexylmethyl acrylate 70 parts n-Butyl Methacrylate 30 parts 2,2'-Azobisisobutyronitrile 5 parts Xylene obtained by heating the above mixture to 120 ° C. After adding 70 parts and 15 parts of isobutyl acetate dropwise to a mixed solvent over 3 hours and maintaining at the same temperature for 5 hours for polymerization, 15 parts of isobutanol was added and a transparent oxirane C1 solution with a solid content of 50% was added. Got The number average molecular weight of this product was about 7,500.

Synthesis Example 11

[0105]

[Chemical 19]

2-Hydroxyethyl methacrylate 25 parts Styrene 10 parts n-Butyl methacrylate 15 parts 2,2'-Azobisisobutyronitrile 3 parts A mixture of xylene heated to 100 ° C. 70 parts, isobutyl acetate 15 parts and iso The mixture was added dropwise to a mixed solvent of 15 parts of butanol over 3 hours, and further maintained at the same temperature for 5 hours to carry out polymerization to obtain a transparent oxirane C2 solution having a solid content of 50%. The number average molecular weight was about 20,000.

Synthesis Example of Hydroxyl Group-Containing Acrylic Resin Synthesis Example 12 n-Butyl Methacrylate 60 parts FM-3X Monomer 40 parts 2,2′-Azobisisobutyronitrile 4 parts Xylene 70 parts obtained by heating the above mixture to 120 ° C. And 15 parts of isobutyl acetate were added dropwise to the mixed solvent over 3 hours, and the mixture was kept at the same temperature for 5 hours. Then, 15 parts of isobutanol was added to the transparent acrylic resin D1 having a solid content of 50%.
A solution was obtained. The obtained resin had a hydroxyl value of 47 and a number average molecular weight of 10,000.

Manufacture of Paint A paint was manufactured using the resins obtained in Synthesis Examples 3 to 12 above. Production Example 1 Copolymer A1 solution 200 having a solid content of 50% obtained in Synthesis Example 3
90 parts of rutile titanium white per 100 parts of solid content
After mixing and dispersing parts, 1 part of tris (n-propylacetoacetate) aluminum, which is a metal chelate curing agent, was mixed with this and uniformly stirred to obtain a coating material.

Production Examples 2 to 10 Each coating material was obtained in the same manner as in Production Example 1 except that the formulations shown in Table 1 below were used. The amounts of raw materials in Table 1 are parts by weight based on the solid content (the metal chelate curing agent is the amount of active ingredient).

(Note) in Table 1 is as follows. (Note 2) Rika Resin 1000: manufactured by Shin Nippon Rika Co., Ltd.
Aliphatic epoxy group-containing polyester oligomer has about 4 alicyclic epoxy groups in one molecule. (Note 3) Oxirane compound: An alicyclic oxirane group-containing compound represented by the following chemical formula.

[0111]

[Chemical 20]

[0112]

[Table 1]

Example 1 An electrogalvanized steel sheet having a thickness of 0.5 m / m and KP color 84
16 primer (Kansai Paint Co., Ltd., epoxy resin type primer for precoat metal) dry film thickness of about 4 μm
The maximum temperature (MT) reached by the material is 2
A primer-coated plate was obtained by baking for 30 seconds under the condition of 00 ° C. This primer-coated plate was coated with the coating material obtained in Production Example 1 to a dry film thickness of about 18 μm, and baked for 30 seconds under the condition that the maximum temperature reached by the material was 150 ° C. to obtain a top-coated plate.

Examples 2 to 10 The same procedure as in Example 1 was repeated, except that the type of paint to be applied on the primer-coated plate and the baking conditions for this paint were as shown in Table 2 below. A top coated plate was obtained.

Example 11 An upper coated plate was obtained in the same manner as in Example 1 except that an untreated aluminum plate having a thickness of 0.5 m / m was used instead of the primer coated plate.

Example 12 An overcoated plate was obtained in the same manner as in Example 4, except that an untreated aluminum plate having a thickness of 0.5 m / m was used in place of the primer coated plate.

Comparative Example 1 In Example 1, instead of the coating material obtained in Production Example 1, KP was used.
Color 7516 White (manufactured by Kansai Paint Co., Ltd., silicone polyester top coating, white, in Table 2 "KP751"
6 ”is abbreviated. ) Is used and the baking conditions for this paint are M.
T. Was 230 ° C. and the baking was performed for 45 seconds to obtain a top coated plate in the same manner as in Example 1.

Comparative Example 2 In Example 1, instead of the coating material obtained in Production Example 1, KP was used.
Color 1573 White (Kansai Paint Co., Ltd., polyester resin-based top coating, white, "KP1573" in Table 2)
Abbreviated. ) Is used and the baking conditions for this paint are M. T. Was 210 ° C. and baking was performed for 45 seconds to obtain a top-coated plate in the same manner as in Example 1.

Examples 1 to 12 and Comparative Examples 1 and 2
All of the top-coated coated plates obtained in 1. had good coated surface appearance. Various tests were performed on the top-coated plate obtained in each example. The test results are shown in Table 2 below. The tests in Table 2 were performed according to the following test method.

Coating surface gloss: JIS K 5400 7.6
According to the 60 degree specular gloss of (1990), the reflectance (%) was measured when the incident angle and the light receiving angle were each 60 degrees. Pencil hardness: A pencil scratching test specified in JIS K5400 8.4.2 was performed to evaluate the scratches.

Workability: In a room at 20 ° C., the test plate was bent 180 ° with the coated surface facing outward, and the T number at which cracks did not occur at the bent portion was displayed. The T number is 0T when 180 ° bending is performed without sandwiching anything inside the bent portion, and 1T when 1 plate having the same thickness as the test plate is bent and 1T, 2 The number of sheets was 2T, and the number of sheets was 8T.

Oil resistant ink stain resistance: A line was drawn on the coated surface with magic ink red (oil based ink) in a room at 20 ° C., left for 1 hour, and then wiped off with a gauze soaked with ethanol. The appearance of the traces of the red and red magic ink wiped off was evaluated. The appearance was visually evaluated according to the following criteria. A: No trace is observed. ○: A trace is slightly recognized. Δ: A considerable mark remains. X: The trace remains thick.

Carbon stain resistance: 1 cc of a dispersion of carbon black / water = 2/98 (weight ratio) was placed on the coated surface, left standing in a thermostatic chamber at 150 ° C. for 8 hours, and then washed with water to obtain a dispersion. The degree of discoloration of the coated surface of the portion on which was placed was visually determined. A: No trace is observed. ○: A trace is slightly recognized. Δ: A considerable mark remains. X: The trace remains thick.

Solvent resistance: About 1 kg / cm ^{2 on the} coated surface with gauze soaked with methyl ethyl ketone in a room at 20 ° C.
The load was applied to and reciprocated between lengths of about 5 cm. The number of times of reciprocation until the primer coating film is visible is described. When the primer coating film was not visible after 50 round trips, it was indicated as 50 <.

Acid resistance: A test piece was immersed in a 5% aqueous solution of sulfuric acid at 60 ° C. for 3 hours, and the coated surface was visually evaluated. Those with no abnormalities were marked with ◎, and those with blisters were marked with blisters.

Adhesion to bent parts: When the test plate is bent 180 ° with the coated surface facing outward, three plates having the same thickness as the test plate are sandwiched and bent for 3T bending. The degree of remaining of the coating film when the tape was attached to the bent portion and immediately peeled off was evaluated. Further, the coated plate after the test plate was immersed in boiling water for 2 hours was subjected to 3T bending in the same manner as above, and a tape peeling test was performed on the processed portion to evaluate the degree of remaining coating film. When there was no or almost no peeling of the coating film, it was rated as O.

Accelerated weather resistance: The gloss retention rate (%) of the coating film was examined by a sunshine weatherometer until the irradiation time reached 2,000 hours.

[0128]

[Table 2]

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁵ Identification code Internal reference number FI Technical display location C09D 163/00 PKB 8830-4J 183/04 PMS 8319-4J // C08F 299/08 MRY 7442-4J

Claims (8)

[Claims] 1. An alkoxysilane group- and / or silanol group-containing vinyl monomer and an oxirane group-containing vinyl monomer are used as monomer components on a metal plate with or without an undercoat coating film interposed therebetween. A precoated coated plate formed by forming a cured coating film of a coating composition containing a copolymer and a metal chelate curing agent as vehicle components. 2. A vinyl monomer containing an alkoxysilane group and / or a silanol group is represented by the following general formula [1]: [In the formula, A represents -C (O) O- or a phenylene group;
₁ is a hydrogen atom or a methyl group, R ₂ is an aliphatic hydrocarbon group having 1 to 6 carbon atoms, R ₃ is the same or different and is a phenyl group, an alkyl group having 1 to 6 carbon atoms, or an alkyl group having 1 to 6 carbon atoms. An alkoxyl group or a hydroxyl group, R ₄ represents a hydrogen atom or an alkyl group having 1 to 6 carbon atoms, and n represents an integer of 1 to 20. ]
The precoated sheet according to claim 1, which is a compound represented by 3. An alkoxysilane group- and / or silanol group-containing vinyl monomer is a compound represented by the above general formula [1] and the following general formula [2]: [In the formula, R ₅ represents an aliphatic hydrocarbon group having 1 to 8 carbon atoms or a phenyl group, and R ₆ is the same or different and represents a hydroxyl group or an alkoxyl group having 1 to 4 carbon atoms. ] The precoated coated plate according to claim 1, which is a polysiloxane macromonomer obtained by reacting with a compound represented by the formula [1]. 4. An alkoxysilane group- and / or silanol group-containing polymer, a compound or polymer having two or more oxirane groups in one molecule, and a metal with or without an undercoat coating film on a metal plate. A pre-coated plate formed by forming a cured coating film of a coating material containing a chelate curing agent as a vehicle component. 5. The precoat coating according to claim 4, wherein the alkoxysilane group- and / or silanol group-containing polymer is a copolymer containing an alkoxysilane group- and / or silanol group-containing vinyl monomer as a monomer component. Board. 6. The vinyl monomer containing an alkoxysilane group and / or a silanol group is represented by the general formula [1] in claim 2.
5. A compound represented by the above formula or a polysiloxane macromonomer according to claim 3.
Prepainted coated plate as described. 7. A polymer containing an alkoxysilane group and / or a silanol group is represented by the following general formula [3]: Wherein, R ₆ has the same meaning as R ₆ in the formula [2], R ₇ is an aliphatic hydrocarbon group having 1 to 8 carbon atoms, a phenyl group or a C 7-10 3,4 Indicates an epoxycyclohexylalkyl group. ] The precoated coated plate according to claim 4, which is a polysiloxane obtained by reacting a compound represented by the formula: 8. The precoated coated plate according to claim 7, which contains a hydroxyl group-containing acrylic resin as a vehicle component.