JPH09328619A - Curable composition - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a composition having excellent curability, scratch resistance, etc., by using a vinyl polymer having siloxy group, a compound containing a group reactive with hydroxyl group, a catalyst promoting the dissociation of siloxy group and a compound having oxazolidine ring as essential components. SOLUTION: This composition contains, as essential components, (A) a vinyl polymer having at least two siloxy groups in one molecule, (B) a compound reactive with hydroxyl group formed from the component A (preferably a polyisocyanate compound), (C) a catalyst for promoting the dissociation of siloxy group (e.g. phosphoric acids, phosphoric acid esters, p-toluenesulfonic acid, etc.) and (D) a compound having oxazolidine ring. The component A preferably has a siloxy group forming hydroxyl group by hydrolysis in combination with a hydrolyzable silyl group bonded to C atom. An extremely unique and useful composition having excellent coating film appearance and long-term storage stability can be produced by this process.

Description

Detailed Description of the Invention

[0001]

The present invention relates to a novel and useful curable composition. More specifically, the present invention provides
From the fact that a vinyl polymer having a plurality of siloxy groups in one molecule contains a compound having reactivity with a hydroxyl group generated from the polymer, a siloxy group dissociation promoting catalyst, and a compound having an oxazolidine ring. Consists of, inter alia,
The present invention relates to a curable composition having excellent storage stability and curability.

[0002]

2. Description of the Related Art In recent years, in applications for automobiles and automobile repairs, plastics, building materials, etc., paint systems in which acrylic resin and melamine resin are combined, acrylic resin and polyisocyanate compound are used. Paint systems that are used in combination are used.

However, although the former is said to have the advantage of being a one-pack type, it cannot be said that the appearance of the coating film is necessarily excellent due to the heat shrinkage during curing. Moreover, due to the poor acid resistance of the melamine resin,
There are also problems such as deterioration of the coating film due to acid rain during exposure.

The latter is a two-component type, so that it has problems of weighing, a problem of pot life, and the like, and has a problem in workability. Because of that
There is also a method of using a polyisocyanate compound in which the isocyanate group is blocked with an appropriate blocking agent to form a one-pack type, but at the present time, the dissociation temperature of the blocking agent is high, and plastic etc. However, it has a drawback that it is not suitable for coating materials having a low heat resistance temperature.

In order to solve these various problems, Japanese Patent Laid-Open No.
JP-A-2-283163 discloses a technique for a composition in which a copolymer having a siloxy group in the form of a block of a hydroxyl group is used. The composition according to the present technology can be cured at a low temperature, and can improve workability as compared with the existing system using a polyol, and further, p-toluenesulfonyl isocyanate is used. By combining water binders such as
It is possible to improve the storage stability.

However, these monoisocyanates
Although the water-based binder has an excellent moisture trapping effect,
By incorporating the monoisocyanate-based water binder, there is a problem that the curability and scratch resistance of the composition are reduced.

[0007]

As described above, as long as the conventional technique is followed, it is inevitably excellent in curability, scratch resistance, coating appearance and long-term storage stability.
It has been extremely difficult to provide a curable composition having extremely high practicality.

[0008] However, the present inventors have solved various problems or drawbacks in the conventional techniques as described above, and in particular, have a form in which storage stability is further improved, and in addition, curability is improved. In the search for a very useful curable composition having excellent coating film properties such as scratch resistance and coating appearance, the inventors have earnestly started research.

Therefore, the problem to be solved by the present invention is that, in particular, it is excellent in various coating film properties such as curability, scratch resistance, and coating appearance, and is also excellent in long-term storage stability. The purpose is to provide a curable composition having extremely high practicality.

[0010]

Means for Solving the Problems Accordingly, the present inventors have:
Focusing on the problems to be solved by the invention as described above, as a result of intensive and repeated studies, a vinyl polymer having at least two siloxy groups in one molecule and a hydroxyl group formed from the polymer. A curable composition containing a compound having reactivity with a compound, a siloxy group dissociation promoting catalyst, and a compound having an oxazolidine ring as essential components,
In particular, we have found a highly practical curable composition that is excellent in various coating film properties such as curability, scratch resistance, and coating appearance, and is also excellent in long-term storage stability. The present invention has been completed here.

That is, the present invention basically comprises a vinyl polymer (A) having at least two siloxy groups in one molecule, and a compound (B) having reactivity with a hydroxyl group produced from the polymer. ) And a siloxy group dissociation promoting catalyst (C)
And a compound (D) having an oxazolidine ring as an essential component,
It is an object of the present invention to provide a novel curable composition capable of forming a coating film excellent in curability, scratch resistance and coating appearance, and more particularly excellent in long-term storage stability.

[0012]

BEST MODE FOR CARRYING OUT THE INVENTION In the present invention, first, a vinyl polymer (A) having at least two siloxy groups in one molecule.
And a compound (B) having reactivity with a hydroxyl group produced from the polymer, a siloxy group dissociation promoting catalyst (C), and a compound (D) having an oxazolidine ring as essential components. To claim a sex composition,

Further, as the above vinyl polymer (A), at least two siloxy groups in one molecule and a hydrolyzable silyl group bonded to a carbon atom (hereinafter, also referred to as a hydrolyzable silyl group). It is also claimed that a specific curable composition is used, in which a polymer in a form obtained by combining the above is used, and further, as the above-mentioned compound (B) having reactivity with a hydroxyl group, In particular, a specific curable composition, which uses a polyisocyanate compound, is also claimed.

<< Structure >> The present invention will be described in detail below.

First, the vinyl polymer (A), which is one of the essential components constituting the curable composition according to the present invention, will be described. The vinyl polymer (A) has The siloxy group means a compound represented by the following general formula [I]

[0016]

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[Wherein R ₁ has ₁ to 18 carbon atoms]
Or a phenyl group, an aryl group or an aralkyl group, and R ₂ and R ₃ may be the same or different and each represents a hydrogen atom or a halogen atom, or an alkyl group. At least one atomic group selected from the group consisting of a group, a cycloalkyl group, an alkoxyl group, a cycloalkoxy group, an aryl group, an aryloxy group, an alkanoyloxy group, an aralkyl group, an aralkyloxy group, a nitrile group and a halogen atom. Alkyl group, aryl group, cycloalkyl group, aralkyl group, alkanoyl group, alkoxyl group, aryloxy group, cycloalkoxy group, aralkyl, which may or may not be substituted with, having 1 to 18 carbon atoms To represent an oxy group or an alkanoyloxy group I do. ]

It means a group having a structure bonded to a carbon atom represented by

As the siloxy group, only typical ones will be exemplified. A trimethylsiloxy group, a triethylsiloxy group, a triphenylsiloxy group,
Examples thereof include a dimethylethoxysiloxy group and a triethoxysiloxy group. Among them, a trialkylsiloxy group and a trialkoxysiloxy group can be said to have a desirable structure.

To obtain the vinyl polymer (A), for example, a vinyl monomer having a siloxy group (a-
1) and another monomer (a-2) that can be copolymerized, or a method of copolymerizing vinyl polymers having a hydroxyl group prepared in advance with chlorosilane, etc. Such as by reacting with a so-called silylating agent, or by a method such as an alcohol exchange reaction between an alkoxysilane and a hydroxyl group.
Although the vinyl polymer (A) can be prepared in this manner, it is particularly preferable to use the above method because of the ease of preparation.

As the siloxy group-containing vinyl-based monomer (a-1) used for preparing the vinyl-based polymer (A) according to the above-mentioned method, only typical ones are exemplified. If it is limited to, 2-trimethylsiloxyethyl (meth) acrylate, 2-trimethylsiloxypropyl (meth) acrylate, 4-trimethylsiloxybutyl (meth) acrylate, 2-triethylsiloxyethyl (meth) acrylate, 3-tributylsiloxy. Propyl (meth) acrylate, 2-trimethylsiloxyethyl vinyl ether, 4-trimethylsiloxybutyl vinyl ether, 2-trimethylsiloxyethyl allyl ether and the like, the siloxy group-containing monomer (a-1), even when used alone, Or in combination of two or more Good thing is, as a matter of course.

Further, only specific examples of the above-mentioned other copolymerizable monomers (a-2) will be given. Styrene, α-methylstyrene, ter
Various aromatic vinyl monomers such as t-butylstyrene, vinyltoluene or α-chlorostyrene; methyl (meth) acrylate, ethyl (meth) acrylate, n-propyl (meth) acrylate, iso-propyl (meth ) Acrylate, n-butyl (meth) acrylate, iso-butyl (meth) acrylate, ter
t-Butyl (meth) acrylate, 2-ethylhexyl (meth) acrylate, lauryl (meth) acrylate, cyclohexyl (meth) acrylate, benzyl (meth) acrylate, norbornyl (meth) acrylate, isobornyl (meth) acrylate, dibromopropyl (meth) ) Acrylate, tribromophenyl (meth)
Various (meth) acrylates such as acrylates or alkoxyalkyl (meth) acrylates;

Dimethylaminoethyl (meth) acrylate
Or various kinds of dialkylaminoalkyl (meth) acrylates such as diethylaminoethyl (meth) acrylate; or tert-butylaminoethyl (meth) acrylate, tert-butylaminopropyl (meth) acrylate Various amino group-containing monomers such as: (meth) acrylamide, N-methoxymethyl (meth) acrylamide, N-ethoxymethyl (meth)
Various (meth) acrylamide monomers such as acrylamide, N-butoxymethyl (meth) acrylamide or N-methylol (meth) acrylamide;

Diesters of various unsaturated dicarboxylic acids such as maleic acid, fumaric acid or itaconic acid with monohydric alcohols; vinyl acetate, vinyl benzoate or "Veoba" (branched from Ciel, Netherlands) Of various vinyl esters such as vinyl ester of linear aliphatic monocarboxylic acid); "Viscoat BF, BFM,
3F or 3FM "[trade name of fluorine-containing acrylic monomer manufactured by Osaka Organic Chemical Co., Ltd.], perfluorocyclohexyl (meth) acrylate, diperfluorocyclohexyl fumarate or Ni-propyl perfluorooctanesulfonamidoethyl. Containing various (per) fluoroalkyl groups such as (meth) acrylate,
-Vinyl esters, -Vinyl ethers,
Various fluorine-containing compounds such as-(meth) acrylates or unsaturated carboxylic acid esters;

2,3-carbonate propyl (meth) acrylate, 2-methyl-2,3-carbonate propyl (meth) acrylate, 4-methyl-3,4-carbonate butyl (meth) acrylate, 3-methyl-3,
Vinyl monomers containing cyclocarbonate groups such as 4-carbonate butyl (meth) acrylate and 5-ethyl-5,6-carbonate hexyl (meth) acrylate;

1-methoxyethyl acrylate, 1-ethoxyethyl acrylate, 1-benzyloxyethyl acrylate, 1-cyclohexyloxyethyl acrylate, (1-methoxy-1-methyl) Ethyl acrylate, 2-acryloyloxytetrahydrofuran, 2
-Acryloyloxytetrahydropyran, 1-acryloyloxy-1-methoxycyclohexane, 1-methoxyethyl methacrylate, 1-ethoxyethyl methacrylate, 1-isobutoxyethyl methacrylate,

1-benzyloxyethyl methacrylate
1-cyclohexyloxyethyl methacrylate,
(1-methoxy-1-methyl) ethyl methacrylate,
2-methacryloyloxytetrahydrofuran, 1-
Methacryloyloxy-1-methoxycyclohexane, 1-ethoxyethyl chloride, 2-crotonoyloxytetrahydrofuran, 2-crotonoyloxytetrahydrofuran, vinyl 5- (2-ethoxyethoxy) carbonylpentanoate, 5-vinyloxycarbonylpenta Vinyl monomers containing various hemiacetate ester groups or hemiketal ester groups, such as noyloxytetrahydrofuran or monobutyl-mono-1-ethoxyethyl maleate;

Glycidyl (meth) acrylate, β-methylglycidyl (meth) acrylate or (meth)
Various epoxy group-containing monomers such as allyl glycidyl ether; various unsaturated dicarboxylic acids or unsaturated carboxylic acid anhydrides such as maleic anhydride, fumaric acid, itaconic acid or citraconic acid; or (meth ) Various unsaturated monocarboxylic acids such as acrylic acid;

Dialkyl (meth) acryloyloxyalkyl phosphates, (meth) acryloyloxyalkyl acid phosphates, dialkyl (meth)
Acryloyloxyalkyl phosphites, (meth) acryloyloxyalkyl phosphites; or various nitrogen atom-containing compounds such as (meth) acrylonitrile; or vinyl chloride, vinylidene chloride, vinyl fluoride or vinylidene fluoride , Various halogenated olefins.

Further, the hydroxyl group-containing monomer is also within a range that does not impair the storage stability of the resulting curable composition in consideration of the reactivity with the compound (B) to be combined with the vinyl polymer (A). It can also be used in.

As the above-mentioned hydroxyl group-containing monomers, only typical ones are exemplified. 2-hydroxyethyl (meth) acrylate, 2-hydroxypropyl (meth) acrylate, 3-hydroxypropyl (meth). Acrylate, 2-hydroxybutyl (meth) acrylate, 3-hydroxybutyl (meth) acrylate, 4-hydroxybutyl (meth) acrylate, 3-
Chloro-2-hydroxypropyl (meth) acrylate, di-2-hydroxyethyl fumarate or mono-
2-hydroxyethyl-monobutyl fumarate and the like.

Further, 2-hydroxyethyl (meth) acrylate, 2-hydroxypropyl (meth) acrylate, 3-hydroxypropyl (meth) acrylate,
2-hydroxybutyl (meth) acrylate, 3-hydroxybutyl (meth) acrylate or 4-hydroxybutyl (meth) acrylate or 3-chloro-2
-Hydroxypropyl (meth) acrylate, di-2-
Ethylenoxide, propylene oxide, butylene oxide, or ε-caprolactone is added to hydroxyethyl fumarate or mono-2-hydroxyethyl-monobutyl fumarate, usually in the range of 1 to 6 moles for addition reaction. It is also possible to use a long-chain hydroxyl group-containing monomer having a different shape.

In addition, it is desirable that the siloxy group-containing vinyl polymer (A) described above also has a hydrolyzable silyl group in order to make the present invention more effective.

The above-mentioned hydrolyzable silyl group, which has a siloxy group as described above, has the following general formula [II].

[0035]

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[Wherein R ₄ is a hydrogen atom or a monovalent organic group consisting of an alkyl group, an aryl group or an aralkyl group, and R ₅ is a halogen atom or a (substituted) alkoxy group, an acyloxy group, a phenoxy group, Mercapto group,
It represents an amino group, an iminooxy group or an alkenyloxy group, and a is an integer of 0, 1 or 2. ]

It means a compound represented by:

As only such representative hydrolyzable silyl groups, only halosilyl groups, alkoxysilyl groups, acyloxysilyl groups, phenoxysilyl groups, mercaptosilyl groups, aminosilyl groups,
Among them, an iminooxysilyl group or an alkenyloxysilyl group, but the alkoxysilyl group can be said to be a particularly preferable structure in view of the fact that undesirable volatile components are not generated during curing.

Hydrolyzable silyl group-containing vinyl monomer (a) used when preparing the vinyl polymer (A).
As only -3), only typical ones are exemplified by 3- (meth) acryloyloxypropyltrichlorosilane, 2- (meth) acryloyloxypropyldichlorosilane, allylmethyldichlorosilane;
(Meth) acryloyloxypropyltrimethoxysilane, 3- (meth) acryloyloxypropyltriethoxysilane, 3- (meth) acryloyloxypropylmethyldimethoxysilane, allyltrimethoxysilane,
Examples include vinyltriphenoxysilane, vinyltrimethoxysilane, vinyltriethoxysilane, vinyltripropoxysilane, vinylmethyldiethoxysilane, and bis (dimethylamino) methylvinylsilane, but of course, these are only examples. It is not limited.

Of course, these hydrolyzable silyl group-containing vinyl monomers (a-3) may be used alone or in combination of two or more kinds.

In order to prepare the vinyl-based polymer (A) by polymerizing the various vinyl-based monomers as mentioned above, various known and conventional methods can be applied. However, among others, the solution polymerization method using a radical polymerization initiator, that is, the solution radical polymerization method is the most convenient.

As the radical polymerization initiator used at that time, it is needless to say that any radical polymerization initiator generally used for the polymerization of vinyl monomers can be used. Of these, various azo compounds such as azobisisobutyronitrile, di-tert-butylperoxide or benzoylperoxide, or the like are known, if only representative ones are exemplified. These include various conventional organic peroxides.

Further, only typical solvents are exemplified, and various aromatic hydrocarbons such as toluene or xylene; n-pentane, n-
Various aliphatic hydrocarbons such as hexane or n-octane; Various alicyclic hydrocarbons such as cyclopentane, cyclohexane, methylcyclohexane or ethylcyclohexane; Various mixed hydrocarbons such as mineral spirits; Various esters such as ethyl acetate, butyl acetate, cellosolve acetate, diethylene glycol monomethyl ether acetate or diethylene glycol monoethyl ether acetate; or various ketones such as methyl ethyl ketone, methyl isobutyl ketone or methyl amyl ketone.

Further, although it is possible to use alcoholic solvents, it is considered that the curing reaction may be hindered, and the stability is not preferable, so that the object of the present invention is deviated. Unless otherwise specified, or within the range that does not impair the effects of the present invention, it is necessary to use the compound within the range that does not impair the required performance for each application.

As the vinyl-based polymer (A) prepared by using a vinyl monomer, a polymerization initiator and a solvent as described above, a hydroxyl group is generated by hydrolysis of the siloxy group contained therein. Hydroxyl value is about 3
A suitable range is from 0 to about 200, preferably a range from 30 to 150, and the number average molecular weight of the polymer (A) is from about 1,000 to about 50,000. Is appropriate.

If the vinyl polymer is out of the above range, the curability and scratch resistance are inevitably deteriorated, and the coating film appearance and storage stability are remarkably deteriorated. Therefore, either case is not preferable.

That is, when the hydroxyl value is less than about 30, the curability and scratch resistance tend to deteriorate, and when it exceeds about 200 and becomes too high. However, in any case, the dilutability with respect to the solvent is likely to decrease, and in any case, it is not practical.

When the number average molecular weight of the polymer is less than about 1,000, the curability and scratch resistance are apt to decrease, and on the other hand,
If it exceeds about 50,000 and becomes too large,
In any case, the dilutability with respect to the solvents, the storage stability, the appearance of the coating film, and the like are likely to be deteriorated, and in any case, it is not practical.

Then, the above-mentioned compound (B) having reactivity with a hydroxyl group, which is one essential component constituting the curable composition according to the present invention, is at least 2 in one molecule.
It refers to a compound having a group that reacts with individual hydroxyl groups (hydroxyl-reactive group).

To cite only typical examples of the hydroxyl group-reactive group-containing compound (B), so-called hydroxyl group-reactive groups such as an isocyanate group, an acid anhydride group or an epoxy group can be used. It is a compound having at least two in the molecule, and any compound according to such a definition can be used, but in particular, a coating excellent in curability and appearance of a coating film can be used. From the viewpoint of various properties of such a coating film that a film is formed, use of a polyisocyanate compound is particularly desirable.

Of the compounds (B), only typical ones of the above polyisocyanate compounds are exemplified, and examples thereof include tolylene diisocyanate and diphenylmethane diisocyanate.
Various aromatic diisocyanate compounds; various aliphatic diisocyanate compounds such as hexamethylene diisocyanate or trimethylhexane diisocyanate; or isophorone diisocyanate, methylcyclohexane-2,4 (2,6) -diisocyanate,
Various alicyclic diisocyanate compounds such as 4,4-methylenebis (cyclohexylisocyanate) or 1,3- (isocyanatomethyl) cyclohexane;

Various diisocyanates as listed above, various polyhydric alcohols including ethylene glycol, trimethylolethane or trimethylolpropane, and various polyether polyols such as polyethylene glycol or polypropylene glycol. Or an adduct with a relatively low molecular weight polyester resin (including oil-modified type) or an acrylic copolymer such as polycaprolactone polyol having a functional group that reacts with an isocyanate group;

Alternatively, polyisocyanates having a so-called buret structure obtained by reacting various diisocyanates such as those listed above with water; or obtained by cyclopolymerization of various diisocyanates such as those listed above. So-called isocyanurate ring-containing polyisocyanates; or various resins such as vinyl-based polymers, polyester-based polymers, polyether-based polymers or epoxy resins, and further, such as those listed above. Examples include various modified compounds in which isocyanate groups are present in various polymers or resins.

Needless to say, these polyisocyanate compounds may be used alone or in combination of two or more kinds.

The compounding ratio of the compound (B) and the vinyl polymer (A) described above is equivalent to the equivalent ratio of the functional groups (reactive groups) present in the respective components. However, of course, the present invention is by no means limited to only one of these points, and as long as it does not deviate from the object of the present invention and impairs the effects of the present invention, such a blending ratio is appropriately selected. You can

Next, the above-mentioned dissociation accelerating catalyst (C), which is one essential component constituting the curable composition of the present invention, is the water-soluble vinyl polymer (A) as described above. From the siloxy groups it has, it refers to compounds that promote the regeneration of hydroxyl groups,
Further, it also refers to a compound or the like that promotes the reaction between the regenerated hydroxyl group and the above-mentioned hydroxyl group-reactive group-containing compound (B).

As the dissociation accelerating catalyst (C), only typical ones are exemplified, and phosphoric acid, phosphoric acid ester, phosphorous acid ester, unsaturated group-containing phosphoric acid ester and the like are further included. , P-toluenesulfonic acid or an amine salt thereof; various acidic catalysts such as benzoic acid, trichloroacetic acid, naphthalenedisulphonic acid or an amine salt thereof;

Furthermore, ethylenediamine, N-β-aminoethyl-γ-aminopropyltrimethoxysilane,
Such as butylamine, dibutylamine, tert-butylamine, hexylamine or triethylamine,
Various amines; various alkali catalysts such as potassium hydroxide, lithium hydroxide or sodium hydroxide;
Metal salts of various carboxylic acids such as alkyl titanates, dibutyltin dilaurate, dibutyltin diacetate or lead octylate; various sulfides such as monobutyltin sulfide or dioctyltin mercaptide.

Tetramethylammonium fluoride, tetraethylammonium chloride, tetramethylammonium bromide, trimethylbenzylammonium hydroxide, 2-hydroxypyridine, trimethylammonium methoxide, phenyltrimethylammonium chloride, phenyltrimethylammonium bromide, phenyltrimethylammonium hydroxide. Side, phenyltrimethylammonium iodide, phenyltrimethylammonium bromide or phosphocholine chloride sodium salt,

Further, stearyl ammonium bromide, tetra-n-butylammonium hydroxide, tetra-n-butylammonium phosphate,
Tetra-n-dodecyl ammonium trichloride, tetraethyl ammonium hydroxide, tetraethyl ammonium tetrafluoroborate, acetylcholine bromide, alkyldimethylbenzyl ammonium chloride, benzylcholine bromide, benzyl-n
-Butyl ammonium bromide, betaine, butyryl chloride, bis (tetra-n-butyl ammonium)
Various quaternary ammonium salts such as dichromate or trimethylvinyl ammonium bromide;

Alternatively, allyltriphenylphosphonium chloride, n-amyltriphenylphosphonium bromide, benzyltriphenylphosphonium chloride, bromomethyltriphenylphosphonium bromide, 2-dimethylaminoethyltriphenylphosphonium bromide , Various phosphonium salts such as ethoxycarbonylphosphonium bromide, n-heptyltriphenylphosphonium bromide, methyltriphenylphosphonium bromide, tetrakis (hydroxymethyl) phosphonium sulfate or tetraphenylphosphonium bromide;

Furthermore, 1,8-diazabicyclo (5,5
4,0) undecene-7 or various basic catalysts such as 1,4-diazabicyclo (2,2,2) octane; or various carbonates such as calcium carbonate, but addition of the catalyst The amount is appropriately within the range of about 0.001 to about 10%, preferably within the range of 0.002 to 6% with respect to the above vinyl polymer (A).

Next, the above-mentioned compound (D) having an oxazolidine ring, which is one essential component constituting the curable composition of the present invention, is at least 1 in one molecule.
It refers to a compound having one oxoxazolidine ring and having reactivity with water.

As the compound (D) having an oxazolidine ring, only typical ones are exemplified. 3-ethyl-2-methyl-2,2-dimethyl-
1,3-oxazolidine, 3-ethyl-2-methyl-2
-(3-Methylbutyl) -1,3-oxazolidine, 4
-Methyl-3-ethyl-2-methyl-2- (3-methylbutyl) -1,3 oxazolidine or 4-ethyl-2
Various oxazolidine compounds such as -methyl-2- (3-methylbutyl) 1,3 oxazolidine; or aldimine-oxazolidine compounds, and the amount of the compound (D) added is the curable composition of the present invention. About 0.05 to about 20 relative to the total amount of resin solids in the product
%, Preferably 0.1 to 10%.

In the curable composition of the present invention, the compound (D) as described above may be used as long as it does not deviate from the object of the present invention or in an amount within the range that does not impair the effects of the present invention. Other than the so-called water-binding agent can be used in combination.

Of the compounds which can be used as such a water-binding agent, only typical ones are exemplified, and various trialkyl orthoformates such as trimethyl orthoformate, triethyl orthoformate or tributyl orthoformate; ortho Various trialkyl orthoacetates such as trimethyl acetate, triethyl orthoacetate or tributyl orthoacetate; such as tetramethyl silicate, tetraethyl silicate, tetrabutyl silicate, tetra (2-methoxyethyl) silicate or tetra (2-chloroethyl) silicate , Various tetra (substituted) alkyl silicates alone; or various same-effect substances of the above-mentioned tetra (substituted) alkyl silicates such as tetraphenyl silicate or tetrabenzyl silicate. Referred to as non-consolidated).;

Alternatively, various types of the above-listed compounds, such as tetraethyl silicate dimer, trimer, tetramer or hexamer, or "ethyl silicate 40" (a mixture of tetraethyl silicate tetramers, pentamers or hexamers manufactured by Colcoat, USA). Hydrolyzable ester compounds such as tetra (substituted) alkyl silicates simple substance and condensates of same-effect simple substance of the silicates; further, phenyl isocyanate, p-chlorophenyl isocyanate, benzene sulfonyl isocyanate, p-toluene sulfonate And various isocyanate group-containing compounds such as isocyanate or isocyanate ethyl methacrylate.

The curable composition of the present invention thus obtained can be used as it is as a clear paint, or can be used in combination with an ordinary colored base paint as a 2 coat 1 bake clear paint. You can

Further, it is possible to add a metallic powder and / or a coloring pigment to obtain a so-called colored paint. As the metallic powder, only typical ones are exemplified by aluminum powder, copper powder, mica powder, titanium oxide-coated mica powder, and mica-like iron oxide. Also,
As the above-mentioned coloring pigments, only typical ones are exemplified, so-called inorganic pigments such as titanium oxide, red pearl or oxide yellow, phthalocyanine pigments, quinacridone pigments or azo pigments. The so-called organic ones.

The curable composition according to the present invention may further contain various fibrous resin such as nitrocellulose or cellulose acetate butyrate, if necessary;
Vinyl chloride / vinyl acetate copolymer resin, ketone resin or petroleum resin; various acrylic polymers, oil-free alkyd resins other than the vinyl polymer (A) and the compound (B), respectively, as described above. An alkyd resin or an epoxy resin can also be blended.

The curable composition according to the present invention further comprises
For example, leveling agents, rheology control agents,
Various known and conventional additives such as a light stabilizer and an ultraviolet absorber can also be incorporated.

The curable composition of the present invention thus obtained is suitable for spray coating, and the drying condition after coating may be room temperature or heat drying. Depending on the type and characteristics of
Just decide.

Needless to say, the curable composition according to the present invention obtained as described above is particularly excellent in curability, scratch resistance and coating film appearance.
It is also excellent in long-term storage stability.

Therefore, as detailed above,
The curable composition according to the present invention is extremely highly practical especially for various coatings such as automobiles and automobile repairs, plastics and building materials.

The curable composition of the present invention is very effectively used and applied for applications other than those described above, and mainly for coating, for example, for building exteriors or for heavy corrosion protection. You can do it.

Here, to exemplify only a particularly representative base material to be coated, aluminum,
Materials or products of ferrous or non-ferrous metals, such as stainless steel, chrome-plated, galvanized steel or tin plate, or as described above;
Various materials or products, which are used for various woodworking, construction, building materials, glass, or various plastic products, which are publicly known and commonly used.

[0077]

Now, the present invention will be described in further detail with reference to Reference Examples, Examples and Comparative Examples. However, the present invention is in no way limited to only these illustrative examples. Not like that. In the following, all parts and percentages are by weight unless otherwise specified.

Reference Example 1 [Preparation Example of Vinyl Polymer (A)] 300 parts of xylene was placed in a reaction vessel equipped with a stirrer, a nitrogen gas inlet tube, a thermometer and a reflux condenser, and the temperature inside the vessel was adjusted to 110. The temperature was raised to ℃.

Next, 180 parts of styrene, 180 parts of trimethylsiloxyethyl methacrylate, tert-
From a monomer mixture consisting of 180 parts of butyl methacrylate and 60 parts of n-butyl methacrylate, 12 parts of azobisisobutyronitrile, 2 parts of tert-butyl perbenzoate and 100 parts of butyl acetate. Was added dropwise over 5 hours.

After the dropping is completed, the non-volatile content is reduced to 60 by keeping the same temperature for 10 hours.
%, To obtain a solution of the target polymer (A). Hereinafter, the solution of the vinyl polymer (A) is abbreviated as (A-1).

Reference Example 2 (Same as above), except that the monomers to be used were 240 parts of styrene, 18 parts of isobutyl methacrylate, 174 parts of n-butyl methacrylate and 168 parts of trimethylsiloxyethyl methacrylate. The reaction was carried out in the same manner as in Reference Example 1 to obtain a solution of the objective vinyl polymer (A) having a nonvolatile content of 60%. Hereinafter, the solution of the vinyl polymer (A) is (A-
Abbreviated as 2).

Reference Example 3 (same as above) The monomers to be used were changed to 120 parts of styrene, 252 parts of n-butyl methacrylate, 18 parts of 2-ethylhexyl acrylate and 210 parts of trimethylsiloxyethyl methacrylate. By performing the reaction in the same manner as in Reference Example 1 except that
A solution of the objective vinyl polymer (A) having a nonvolatile content of 60% was obtained. Hereinafter, the solution of the vinyl polymer (A) is abbreviated as (A-3).

Reference Example 4 (same as above) The monomer to be used was 180 parts of styrene, tert-
In the same manner as in Reference Example 1, except that 156 parts of butyl methacrylate, 54 parts of n-butyl methacrylate, 180 parts of trimethylsiloxyethyl methacrylate and 30 parts of 3-methacryloyloxypropyltrimethoxysilane were used. By carrying out the reaction, a solution of the objective vinyl polymer (A) having a nonvolatile content of 60% was obtained. Hereinafter, the vinyl polymer (A)
The solution of is abbreviated as (A-4).

Reference Examples 5 to 12 (Preparation Examples of Clear Paint) Each of the vinyl polymers (A-1) to (A-4) obtained in Reference Examples 1 to 4 and a commercially available polyisocyanate. Compounds and the like were used and blended separately according to the blending ratio shown in Table 1.

Then, each of the mixed paints was treated with xylene / toluene / n-butyl acetate / ethyl acetate = 50/10.
Ford Cup No. Various clear paints were prepared by adjusting the viscosity in Step 4 to 15 seconds. Hereinafter, these are sequentially (A
It is abbreviated as C-1) to (AC-8).

[0086]

[Table 1]

<< Footnote of Table 1 >> (Note 1) "DN-901S" ..... "Barnock D
N-901S "(trade name of polyisocyanate compound manufactured by Dainippon Ink and Chemicals, Inc .; isocyanate content = 23.5%)

(Note 2) As the oxazolidine compound, 3-ethyl-2-methyl-2- (3-methylbutyl) -1,3-oxazolidine was used.

[0089]

[Table 2]

<< Footnote of Table 1 (2) >> (Note 3) “PTSI” ……………… abbreviation of p-toluenesulfonyl isocyanate

[0091]

[Table 3]

The clear paints obtained in Examples 1 to 5 and Comparative Examples 1 to 3 and Reference Examples 5 to 9 and Reference Examples 10 to 12 were measured on a zinc phosphate-treated steel sheet, and the gel fraction was measured. On the polypropylene plate for
A coating film for various tests was obtained by applying a coating so that the dry film thickness was 50 micrometers (μm) and heating and drying at 60 ° C. for 30 minutes.

After that, each of the thus obtained test pieces was subjected to various evaluation tests for evaluation of coating film performance. The results are summarized in Table 2.

Test Method and Evaluation Judgment Method

The evaluation of the performance of each coating film shown in Table 2 was carried out according to the following procedure, that is, according to the following method.

Appearance of coating film: After heating and drying, at room temperature, 1
Mainly the smoothness and the sharpness of the coated surface after being left for a week were visually inspected comprehensively and displayed according to the following criteria.

◯: Very excellent Δ: Slightly inferior ×: Remarkably inferior

Curability: After heating and drying, the temperature is kept at room temperature for 2 hours.
The coating film was peeled off from the polypropylene test piece after being left for 0 minutes, and the coating film was immersed in acetone for 2 minutes.
It was soaked for 4 hours. The ratio of the change in weight of the coating film before and after such immersion was expressed as a gel fraction (%).

Coating hardness: After heating and drying, bring to room temperature for 2
The König hardness of the coating film which had been left for 0 minutes was measured by using a pendulum type hardness meter manufactured by Erichsen, Germany. The larger this value is, the harder it is.

Scratch resistance: After heating and drying, at room temperature, 1
For the coating film after leaving it for a week, on the felt,
Impregnated with 5% by weight of cleanser water dispersion, and
The state of the coated surface after applying a load of 00 g and reciprocating 30 times was visually inspected comprehensively and displayed according to the following criteria.

◯: Very excellent Δ: Slightly inferior ×: Remarkably inferior

Storage stability: The clear paint was stored at 40 ° C.
After being stored for 3 months in the atmosphere, the thickened state of the paint was observed and evaluated.

○: No abnormalities △: Slightly thickened ×: Remarkably thickened or gelled

[0104]

[Table 4]

[0105]

[Table 5]

[0106]

As described above in detail, the curable composition according to the present invention is particularly excellent in various coating film properties such as curability and scratch resistance, as well as the coating film appearance. It is said that it has excellent storage stability and is extremely highly practical, and therefore the present invention can provide a curable composition that is extremely novel and useful.

Claims (3)

[Claims] 1. A vinyl polymer (A) having at least two siloxy groups in one molecule, a compound (B) having reactivity with a hydroxyl group produced from the polymer (A), and a siloxy group A curable composition comprising a dissociation promoting catalyst (C) and a compound (D) having an oxazolidine ring as essential components. 2. The vinyl polymer (A) has both a siloxy group which forms a hydroxyl group by hydrolysis and a hydrolyzable silyl group bonded to a carbon atom.
The curable composition according to claim 1. 3. The curable composition according to claim 1, wherein the compound (B) having reactivity with the hydroxyl group is a polyisocyanate compound.