JPH0463884A - Curable composition - Google Patents

Abstract

PURPOSE:To obtain the title composition which is excellent in storage stability and produces a hardened product excellent in chemical resistance, solvent resistance and appearance by mixing a carboxylic acid anhydride, an alkoxysilylated polymer, a water scavenger and a specific compound. CONSTITUTION:The title composition comprises a carboxylic acid anhydride, such as a compound obtained from styrene, n-butyl (meth)acrylate and maleic anhydride, an alkoxysilylated polymer, such as a polymer obtained from 3- methacryloxypropyltrimethoxysilane, n-butyl acrylate and methyl methacrylate, an oxazolidine compound, such as a compound obtained by reacting diisopropanolamine with isobutyraldehyde to produce a hydroxyoxazolidine compound and further reacting the hydroxyoxazolidine compound with dichlorodimethylsilane, and a water scavenger such as trimethoxymethylsilane.

Description

DETAILED DESCRIPTION OF THE INVENTION (Industrial Application Field) The present invention relates to a curable composition having excellent solvent resistance, chemical resistance and durability, and particularly to a curable composition suitable for paints.

(Prior Art) Conventionally, melamine resins and polyisocyanate compounds have been used as hardening agents for hardening paints, but these have had problems such as chemical resistance and toxicity.

To solve this problem, it has been proposed to use blocked amines. However, nothing with excellent performance has yet been obtained.

For example, JP-A-51-116852 discloses a water-curable composition containing an acid anhydride polymer and a polyoxazolidine. This composition also has chemical resistance,
Weather resistance is not sufficient and, furthermore, an excellent finished appearance cannot be obtained.

(Problems to be Solved by the Invention) An object of the present invention is to use an oxazolidine compound to obtain a curable composition with high storage stability that imparts high chemical resistance, weather resistance, and excellent appearance.

(Means for Solving the Problems) In order to achieve the above object, the present inventors have conducted studies and found that excellent performance can be obtained when a polymer having an alkoxysilyl group is used in combination with a water scavenger. They discovered this and came up with the present invention.

That is, the present invention provides a curable composition containing (A) a compound having a carboxylic anhydride group, (B) an oxazolidine compound, (C) a polymer containing an alkoxysilyl group, and (E) a water scavenger. When this composition is further blended with the epoxy compound (D), it becomes higher in solids content and other performances are improved.

The present invention also provides (X) a polymer containing an alkoxysilyl group and either a carboxylic anhydride group or an epoxy group, and (Y) a polymer containing an alkoxysilyl group and containing either a carboxylic anhydride group or an epoxy group. A curable composition is provided that contains a polymer containing one group that is not present in polymer (X), (B) an oxazolidine compound, and (E) a water scavenger.

The present invention further provides a curable composition containing a polymer containing an (X') alkoxysilyl group, a carboxylic anhydride group, and an epoxy group, (B) an oxazolidine compound, and (E) a water scavenger.

Component (A) Various known compounds having a carboxylic anhydride group used in the present invention include maleic anhydride,
low molecular weight acid anhydrides such as phthalic anhydride, hydrogenated phthalic anhydride, 4-methyl hydrogenated heptalic anhydride, pyromellitic anhydride, pyromellitic anhydride triglyceride, trimellitic anhydride ethylene glycol ester, or mixtures thereof;
Alternatively, high molecular weight acid anhydrides such as copolymers of ethylenic acid anhydrides such as itaconic anhydride and maleic anhydride and other copolymerizable monomers may be mentioned. Other copolymerizable monomers include styrene, α-methylstyrene, acrylic esters (e.g., methyl acrylate, ethyl acrylate, butyl acrylate, or 2-ethylhexyl acrylate, acrylic esters (e.g., methacrylic acid). Methyl, ethyl methacrylate, butyl methacrylate, isobutyl methacrylate, t-butyl methacrylate, 2-ethylhexyl methacrylate or lauryl methacrylate), acrylamide, methacrylamide, etc. Copolymerization can be carried out by known methods, such as radical polymerization. The number average molecular weight of the copolymer is 500 to 40.0.
00, preferably i. ooo~20,000. 4
When it is larger than 0,000, the viscosity of the copolymer becomes high, which has the drawback that it is difficult to form a high solid content thermosetting composition.

If it is less than 500, the curability is not sufficient. Note that the molecular weight is determined by GPC method. The acid value of high molecular weight acid anhydride is 30
-500, preferably 50-350. Compounds having carboxylic anhydride groups (hereinafter referred to as acid anhydrides) are classified into monovalent, divalent, and trivalent with respect to the acid anhydride group.
In the present invention, polyvalent acid anhydrides of divalent or higher valence are preferred because they provide high curability. Examples of preferred acid anhydrides include trimellitic anhydride ethylene glycol ester, trimellitic anhydride triglyceride, and water additives thereof;
or a high molecular weight acid anhydride.

Component (B) The oxazolidine compound is blocked by a reaction between an alkanolamine compound containing a primary or secondary amine and a hydroxyl group in its molecule and a ketone or aldehyde. The "oxazines" of the present invention include 5-membered ring oxazolidines and 6-membered ring tetrahydro-1,3-oxazines.

This compound can be, for example, mono- or jetanolamine,
Alkanolamines such as mono- or dibrobanolamine, mono- or diisopropanolamine, 1N-methylethanolamine, biterminal amines (e.g. ethylenediamine, hexamethylenediamine, inphorondiamine) and epoxy compounds (e.g. ethylene oxide). , butylene oxide, etc.) and ketones such as acetone, methyl ethyl ketone, methyl isobutyl ketone, cyclohexanone, isophorone, or benzaldehyde, isobutyraldehyde, acetaldehyde, propionaldehyde, n-
It can be obtained by a dehydration reaction with an aldehyde such as butyraldehyde. In addition, polyfunctional oxazolidine compounds are obtained by dehydrating alkanolamines such as jetanolamine and diisopropanolamine with the above-mentioned ketones and aldehydes to obtain oxazolidine compounds having hydroxyl groups, which can be used to form various reactive compounds. , an acid chloride, a metal halide compound, or the like. Examples of the reactive compound include isocyanate compounds, specifically hexamethylene diisocyanate, isophorone diisonate, xylene diisonate, 1,3-(incyanatomethyl)cyclohexane, and the like. Examples of acid chlorides include adipoyl dichloride, sepatic acid dichloride, decanoic acid dichloride, and terephthalic acid dichloride. Using metal halide compounds! As an example of the oxazolidine compound, the oxazolidine compound represented by the above formula [1] is represented by the formula % formula % [wherein R, n and M have the same meanings as above. X represents a halogen atom. ] The compound represented by the formula [wherein R is a hydrogen atom or an alkyl group having 1 to 10 carbon atoms, an aryl group, a vinyl group, a halogenated alkyl group, or an alkoxy group, n is an integer of θ to 3, M represents a silicon or titanium atom, R1 represents an alkyl group having 2 to 5 carbon atoms, R2 and R3 represent a hydrogen atom, an alkyl group or an aryl group having 1 to 10 carbon atoms, and R' represents a hydrogen atom or a methyl group. ] Compounds represented by these can be mentioned.

[In the formula, R1 to R6 have the same meanings as above. It is obtained by reacting the hydroxyoxazolidine compound represented by 1. This synthesis reaction is represented by the following reaction formula.

[I] [wherein R, n, MlX and Rl to R4 have the same meanings as above. ] The compound represented by the above formula [1] is a halogenated silane compound or a halogenated titanium compound. Examples of halogenated silane compounds include methyltrichlorosilane, methyldichlorosilane, dimethylcyclolonane,
Phenyltrichlorosilane, diphenyldig00silane, tetrachloro/ran, vinyltrichlorosilane, chloromethyltrichlorosilane, ethyltrichlorosilane,
Examples include dimethoxymethylchlorosilane, jetoxydichlorosilane, and triethoxychlorosilane.

Examples of the halogenated titanium compound include tetrachlorotitanium.

The hydroxyoxazolidine compound represented by the above formula [II[1] can be obtained by a normal oxazolidine synthesis reaction as described below.

Specific examples of the hydroxyoxazolidine compound [I[[] include 2-isopropyl-3-(2-hydroquinepropyl)-5-methyloxazolidine, 2,2-dimethyl-3-(2-hydroxypropyl)-5- Methyloxazolidine, 2-phenyl3-(2-hydroquinepropyl)-5-methyl(2oxazolidine, 2-isopropyl-3-(2hydroxyethyl)oxazolidine, 2-7
Methyl-2-isobutyl-3-(2-hydroxyethyl)oxazolidine and 3-(2-hydroquinepropyl)
-5-methyloxazolidine and the like.

According to the method of the present invention, the above compound [I! ] and the above compound [111] are reacted in a non-polar solvent in the presence of a base such as pyridine or triethylamine as a trapping agent for the generated hydrochloric acid at a reaction temperature of 30°C or less for 1 to 5 hours to form compound [II]. can get. If the reaction temperature is higher than 30° C., the produced compound [II] may decompose, which is not preferable.

This special oxazolidine compound [II is the above component (A
) can be combined with a compound having a carboxylic anhydride group to form a curable m-acid.

In addition, polymers containing alkoxysilyl groups (C
) can also be used in combination with a curable composition.

The amount of component (B) in the composition is 0.2 to 3 equivalents, preferably 0.5 to 2 equivalents of the amino groups formed per equivalent of carboxylic anhydride group of component (A).

When the amount is less than 0.2 equivalent, good crosslinking density cannot be obtained and solvent resistance is insufficient. If the amount exceeds 3 equivalents, weather resistance will decrease.

Component (C) A polymer containing an alkoxysilyl group can be obtained by various methods. The simplest method is (1) 3-methacryloxypropyldimethoxymethylsilane, a silane compound having a polymerizable double bond and an alkoxy group in the molecule such as 3-methacryloxypropylmethoxysilane, which can be copolymerized with other silane compounds. compounds (e.g. styrene monomer, α-methylstyrene, esters of acrylic or methacrylic acid with various alcohols (e.g. methyl methacrylate, ethyl methacrylate, ethyl acrylate, butyl methacrylate, butyl acrylate 2-ethylhexyl methacrylate, It can be obtained by copolymerization or homopolymerization with 2-ethylhexyl methacrylate).

Another method is (2) a method obtained by modifying a polymer with a silane compound. For example, after copolymerizing allyl methacrylate (or allyl acrylate) with other copolymerizable monomers listed above, a 5i-H group such as dimethoxysilane, trimethoxysilane, triethoxysilane, dimethoxy/methyl heptane, etc. This is a method in which a silane compound containing a silane compound is introduced by silyl hydration under a platinum-based catalyst. Also, as another method, (3)
The compounds having an unsaturated group copolymerizable with an incyanato group are listed above: 3-aminopropyltrimethoxysilane, 3-aminopropyldimethylethoxysilane, 3-allyl after copolymerizing with other copolymerizable monomers. A method of introducing an alkoxyrane compound having -NH- (or -NH,) in the molecule, such as aminoclovirtrimethoxysilane and 3-aminopropyltriethoxysilane compound, with an incyanato group, or mercapto Methyltrimethoxysilane, dimethoxy-
There is a method of introducing an alkoxysilane compound having a --SH group in the molecule, such as 3-mercaptopropylmethylsilane or 3-mercaptopropyltrimethoxysilane, by reacting it with an incyanato group.

Furthermore, (4) unsaturated double bonds are introduced into the polymer by reacting glycidyl methacrylate (or methacrylic acid) with a polymer containing a carboxyl group (or glycidyl group), and one of the above-mentioned double bonds is introduced by a Michael reaction. There is also a method of introducing an alkoxysilyl group having an NH group. Among these methods, methods (1) and (2) are particularly convenient and good.

There is no particular limit to the amount of silyl compound in the copolymer, but 2
0 to 100% is preferred. If it is less than 20%, problems remain in curability. The molecular weight of this polymer is 500-40,000
, preferably 1.000 to 2o, ooo. 500
If it is smaller than this, there will be problems with curing properties, and if it exceeds 40°000, it will be difficult to form a paint with a high solid content, and it will have drawbacks such as poor compatibility.

The amount of alkoxysilyl group in the composition is not more than IO equivalent of alkoxysilyl group in the polymer containing the alkoxysilyl group per equivalent of acid anhydride group, preferably 0.1 to 10.
5 equivalents. If the amount is 5 equivalents or more, water resistance deteriorates.

Component (D) The epoxy compound used is a compound having at least one oxirane group in one molecule. Such epoxy compounds include glycidyl ethers such as ethylene glycol diglycidyl ether, propylene glycol diglycidyl ether, 1,6-hexanesiol glycidyl ether, trimethylolpropane triglycidyl ether, bisphenol A-diglycidyl ether and hydrogenated Glycidyl esters such as bisphenol A-diglycidyl ether, such as adipic acid, diglycidyl ester, hydrogenated phthalic acid diglycidyl ester,
Phthalic acid diglycidyl ester and trimellitic acid triglycidyl ester, etc., and cycloaliphatic epoxies, such as 3,4-epoxycyclohexylmethyl-3,4-
Epoxycyclohexane carboxylate, bis-(3
Examples include 4-epoxycyclohexyl adipate and vinylcyclohexene dioxide.

Furthermore, commercial products such as ERL-4221 (manufactured by UCC),
ERL-4299 (manufactured by UCC), Epolite 1600
(manufactured by Kyoeisha Yushi) and Evolite 4000 (manufactured by Kyoeisha Yushi) may also be used. The epoxy compound may be a polymer. Examples of such polymers include high molecular weight epoxy compounds such as copolymers of ethylenic epoxies such as glycidyl methacrylate and glycidyl acrylate with other copolymerizable heptamers. Other copolymerizable heptamers used here include styrene,
α-methylstyrene, acrylic esters (e.g.
Methyl acrylate, ethyl acrylate, butyl acrylate, or 2-ethylhexyl acrylate), methacrylic esters (e.g., methyl methacrylate, ethyl methacrylate, butyl methacrylate, isobutyl methacrylate, t-butynomethacrylate, methacrylic acid 2) -ethylhexyl or lauryl methacrylate), acrylamide, methacrylamide, and the like. Copolymerization is carried out by a known method such as radical polymerization. The number average molecular weight of the copolymer is 500 to 40°000, preferably 1
,000 to 20,000. When it is larger than 40,000, the viscosity of the copolymer becomes high, which has the drawback that it is difficult to form a high solid content thermosetting composition. If it is less than 500, the curability is not sufficient. Note that the molecular weight is determined by GPC method.

The amount of component (D) in the composition is 0.2 to 3 equivalents of epoxy group per equivalent of carboxylic anhydride group of component (A),
Preferably it is 0.5 to 1.0 equivalent.

If the amount is less than 0.2 equivalent, sufficient curability cannot be obtained;
If the amount is more than the equivalent amount, weather resistance decreases, which is not preferable.

Component (E) Used for the purpose of removing moisture present in paint. In the present invention, a water scavenger is added to improve storage stability. Examples of water scavengers include orthoesters such as trimethyl orthoformate, triethyl orthoformate, trimethyl orthoacetate, triethyl orthoacetate, trimethyl orthoborate and triethyl orthoborate; silicones;
For example, dimethyldimethoxysilane, trimethylmethoxysilane, methyltrimethoxysilane, tetramethoxylane, tetraethquinsilane and tetraphenoquinsilane, etc.; Isocyanates, such as phenyl isocyanate, butyl isocyanate and hexamethylene diisocyanate, etc.; Metals, such as sodium , potassium, aluminum, lithium, etc.: Inorganic salts such as potassium chloride, sodium chloride, calcium chloride, etc. The water scavenger is 0.1 to (0) based on the solid content of the paint.
It is blended in an amount of 0.5 to 5% by weight, preferably 0.5 to 5% by weight. 0.5
If it is less than % by weight, the storage stability of the paint will decrease. Components (X, X' and Y) whose curability deteriorates when the amount exceeds 5% by weight Components (A), (C) and (D) are one or two polymers containing groups corresponding to each component. You can. Specifically, a polymer (X) containing an alkoxysilyl group and either a carboxylic anhydride group or an Epoquine group, and a polymer (Y) containing an alkoxysilyl group and a group not found in the polymer (X). or a polymer (X') in which all of these groups are contained in one molecule. Polymer (x, x' and Y
) are described in the preparation of components (A), (C) and (D); the heptamers containing the respective groups and, if necessary, other copolymerizable heptamers (as described in components A, C and D). It can be obtained by copolymerizing the following:

The amount of each group present is preferably within the ranges described for components (A), (C) and (D).

Other Components The curable compositions of the present invention may be used as coating compositions. The above components may be formulated into a clear coating composition, or they may be combined with pigments to form a paint. As a side effect, when this acid anhydride group modified polymer is modified with dimethylamine ethanol, for example, it has an acid and an amine in the molecule and becomes amphoteric, resulting in excellent pigment dispersibility. . Pigments may be of any conventional type, such as iron oxide, lead oxide, strontium chromate, carbon black, cold dust, titanium dioxide, talc, barium sulfate, cadmium yellow, cadmium red, chrome yellow and metals. It may also be a pigment, such as aluminum flakes.

It may also be an organic pigment, such as phthalocyanine blue and Shinkasha red.

Also, pearl mica and the like can be used. Pigment content in paints is usually expressed as a pigment to nonvolatile weight ratio of the coating composition. In the practice of this invention, the pigment to coating composition non-volatile weight ratio may be as high as 2:l, often in the range of 0.05 to 1:l, to achieve the desired brightness and appearance. can be determined by

In coating compositions, a liquid diluent is usually present in the composition. A liquid diluent is a solvent or non-solvent that is volatile, is removed after application, and is capable of applying a film to a desired uniform and controllable thickness by a simple application method, i.e. by spraying. It is necessary to reduce the viscosity. The liquid diluent also aids in substrate wetting, polymer component compatibility, pancage stability and coalescence or film forming properties. Examples of suitable diluents include aromatic hydrogen dihydrides such as toluene and xylene, ketones such as methyl ethyl ketone and methyl isobutylethyl ketone, monoether glycol acetates such as 2-ethoxyethyl acetate, or compatible mixtures thereof. Can be mentioned.

In addition to the above ingredients, various fillers, plasticizers, antioxidants,
Ultraviolet absorbers, flow control agents, surfactants, and other formulation additives may be used as desired. These materials may be optionally present, typically up to about 10% by weight based on the non-volatile content of the coating composition.

The coating composition may be applied by spray coating, brush coating, dip coating, roll coating, flow coating, and the like. The coating composition may be applied to essentially any substrate, such as wood, metal, glass, cloth, plastic, foam, etc., or to a variety of primer surfaces. The paints are particularly advantageous for plastic and metal surfaces, such as steel and aluminum.

Generally, the film thickness will vary depending on the desired application. Often 0.5 to 3 mils are useful.

After coating the base material, the coating film is cured. Curing is 1°0-20
A cured coating film with a degree of crosslinking as high as 0°C, preferably 120-180°c-c' is obtained. The curing time varies depending on the curing temperature, etc., but curing for 10 to 30 minutes at 120 to 180°C is appropriate.

The curable composition of the present invention may be used for molding and other purposes.

- (Effect of the invention) In the present invention, by adding a polymer having an alkoxysilyl group to a compound having an acid anhydride group or an oxazolidine compound, higher solvent resistance, chemical resistance, and durability are imparted to the cured product. . In addition, the water scavenger suppresses hydrolysis of oxazolidine and improves storage stability.

Furthermore, when formed into a coating film, excellent smoothness can be obtained. The reason why such excellent effects are obtained is thought to be that the hydroxyl group formed by hydrolysis of oxazolidine reacts with the polymer containing the alkoxysilyl group and the acid anhydride group, resulting in crosslinking. When the epoxy compound (D) is included, this epoxy compound is considered to further participate in crosslinking.

(Example) The present invention will be explained in more detail with reference to Examples. The present invention is not limited to these examples.

Production Example 1 Synthesis of a compound containing a carboxylic anhydride group 300 g of butyl acetate was charged into a 2Q reaction vessel equipped with a thermometer, a stirrer, a cooling tube, and a nitrogen introduction tube, and the temperature was raised to 120°C, and 300 g of styrene and n- Butyl acrylate 270
A monomer and initiator solution consisting of 21 og of n-butyl methacrylate, 220 g of maleic anhydride, 400 g of propylene glycol monomethyl ether acetate, and 100 g of t-butyl peroxyhexanony) was
The mixture was added dropwise over an hour and stirring was continued for an additional 2 hours.
%, an acrylic resin having a number average molecular weight of 3,000 was obtained.

Production Example 2 Synthesis of Polymer Containing Alkoxysilyl Groups 720 g of xylene was placed in the same reaction vessel as in Production Example 1, heated to 120°C, and 750 g of 3-methacryloxypropyltrimethoxysilane, n-butyl acrylate long, and methyl methacrylate were added. A 7-mer initiator solution consisting of 50 g of L-N and 80 g of t-butyl peroxyhexanoate was added dropwise over 3 hours, and the reaction was continued for an additional 2 hours.
A polymer containing an alkoxysilyl group with a number average molecular weight of 2.000 was obtained.

・Production Example 3 Synthesis of a polymer containing an Epoquine group 700 g of xylene was charged into a container similar to Production Example 1, and 1
Raise the temperature to 30°C and add 500g of Grindyl methacrylate.
, styrene 50g1 methyl methacrylate) 120g%
A 7-mer initiator solution consisting of 330 g of n-butyl acrylate and 100 g of t-butyl peroxyhexanoate was added dropwise over 3 hours, and stirring was continued for 2 hours to obtain a solution with a non-volatile content of 61% and a number average molecular weight of 2,500. of acrylic resin was obtained.

Production Example 4 Synthesis of a polymer containing a carboxylic anhydride group and an alkoxysilyl group Using the same conditions as Production Example 1, 100 g of styrene was added.

2-ethylhexyl methacrylate 520g, isobutyl methacrylate 12C1g, maleic anhydride 200g
g13-methacryloxypropyltrimethquine silane 5
0g1 propylene glycol monomethyl ether acetate 280g and t-butyl peroxyhexanony
Using a monomer initiator solution containing NOOg, the non-volatile content is 5.
An acrylic resin having a number average molecular weight of 8% and a number average molecular weight of 3.500 was obtained.

Production Example 5 Synthesis of Polymer Containing Alcoquinnoryl Group and Evoquino Group Under the same conditions as Production Example 3, butyl acetate 4 was used as the pre-added solvent.
70 g and 7-mer initiator solution (500 g of glyc/dyl methacrylate, 220 g of 3-methacryloxypropyltrimethacrylate, 280 g of
g and t-butylbaoquine hexanoate), nonvolatile content 66%, number average molecular weight 3.40.
0 acrylic resin was obtained.

Production Example 6 Synthesis of a polymer containing an alkoxynoryl group and 7 epoxy groups Under the same conditions as Production Example 3, butyl acetate 4 was used as a pre-added solvent.
70 g and 7mer initiator solution (500 g glycidyl methacrylate, 50 g 3-methacryloxypropyltrimethoxysilane, 362 g n-butyl methacrylate)
(containing 88 g of ethyl methacrylate and 100 g of t-butyl baroquine hexanoate), an acrylic resin having a nonvolatile content of 66% and a number average molecular weight of 3,200 was obtained.

Production Example 7 Synthesis of a polymer containing a carboxylic anhydride group, an alkoxynolyl group, and an epoxy group Under the same conditions as Production Example 1, 195 g of styrene, 298 g of 2-ethylhequinyl acrylate, 102 g of inbutyl methacrylate, and 3-methacryloxypropyl trime were synthesized. Using a 7-mer initiator solution containing 94 g of quinsilane, 184 g of glycidyl methacrylate, 127 g of maleic anhydride, 177 g of propylene glycol monomethyl acetate, and 177 g of t-butylperoxyhexanoe HOO, the non-volatile content was 67%, and the number average molecular weight was 3,600. of acrylic resin was obtained.

Production Example 8 Synthesis of Oxazolidine Compound 200 g of benzene and 133 g of diisopropazuramine in a reactor equipped with a stirrer, condenser, thermometer, and water separator.
and 90g of isobutyraldehyde at room temperature.
It dripped in minutes. Further, the generated water was separated and removed under heating under reflux, and the reaction was carried out for 5 hours, and benzene was removed under reduced pressure to obtain a hydroxyoxazolidine compound.

The water separator was blocked, 1000 g of hexane and 103 g of triethylamine were charged, and 64.6 g of dichlorodimethylsilane was added dropwise in OOC over 2 hours. The mixture was further stirred at room temperature for 2 hours, and the solid precipitated in the reaction solution was filtered. The filtrate was concentrated to obtain an oxazolidine compound.

Production Example 9 Synthesis of Oxazolidine Compound An oxazolidine compound was obtained in the same manner as in Production Example 8 using 108 g of benzaldehyde instead of 75 g of isobutyraldehyde.

Production Example 10 Synthesis of Oxazolidine Compound 133 g of diisopropanolamine and 70 g of toluene in a reactor equipped with a stirrer, condenser, thermometer, and water separator.
was charged, and 76 g of isobutyraldehyde was added dropwise over 1 hour while cooling with water. Furthermore, the water generated under heating under reflux was separated and removed, the reaction was carried out for 5 hours, the water separator was removed, and 1.
6-hexane dinitrate 84g, quince 20g
was added dropwise to the above reaction mixture over 1 hour, and the reaction was carried out at 70 to 80°C for 8 hours to obtain an oxazolidine compound.

Production Example 11 Synthesis of Oxazolidine Compound An oxazolidine compound was obtained in the same manner as in Production Example 8, using dodecanoic acid dichloride instead of 64.6 g of dichlorodimethylsilane.

Example 1 A clear paint was prepared with the following formulation, and the performance of the resulting paint film was evaluated.

Prescription manufacturing example 4 100g manufacturing example 5
50.9g Production example 8
25.4g water-trapping IL) lime) Ki/methyl/
Rano 5.0g additive solution
54.6g additive solution Tinuvin 900" 28.0g Tinuvin 1.44*2 21.0g Rubesoso 15
0*3 185.1g diethylene glycol monoethyl ether acetate 92.6
g*1 Ultraviolet absorber manufactured by Ciba Geigy *2 Antioxidant *3 manufactured by Esso Co., Ltd. Butyl acetate/xylene = 1/l
Diluted to paint viscosity with thinner consisting of.

A process test board made of phosphoric acid treated steel plate coated with Nippon Paint Co., Ltd.'s Power Top U-30 and Olga P-2 was coated with Nippon Paint Co., Ltd.'s Super Lac H-90 metallic paste, and then the above clear was applied wet-on-wet. was applied and baked at 140°C for 30 minutes. The coating film evaluation results are shown in Table-2.

Examples 2 to 12 Clear paints were obtained in the same manner as in Example 1 using the formulations shown in Table 1. The coating film evaluation results are shown in Table-2.

Comparative Example A paint was prepared in the same manner as in Example 1 except that Oxazolidine Compound Production Example 8 was omitted.

Table 2 XL Rubbing: Soak gauze in xylene and rub the coating 8 times back and forth to observe changes.

Storage stability: Store the paint at 40°C and observe changes after 10 days.

○ No change △ Shiny pockets, discoloration × Peeling, or dissolution Patent applicant Nippon Paint Co., Ltd. Representative Patent attorney Aoyama Aoyama and 2 others Acid resistance;
Put 6 drops of 6% sulfite water on the paint film and observe the change after 24 hours.

Alkali resistance: Q. Place 6 drops of 1N NaOH aqueous solution on the coating film and observe the change after 24 hours.

Claims (1)

[Claims] 1. A curable composition containing (A) a compound having a carboxylic anhydride group, (B) an oxazolidine compound, (C) a polymer containing an alkoxysilyl group, and (E) a water scavenger. 2. A curable composition containing (A) a compound having a carboxylic anhydride group, (B) an oxazolidine compound, (C) a polymer containing an alkoxysilyl group, (D) an epoxy compound, and (E) a water scavenger. 3. (A) A compound having a carboxylic anhydride group, (B') Formula ▲ Numerical formula, chemical formula, table, etc. ▼ [I] [In the formula, R is a hydrogen atom, an alkyl group having 1 to 10 carbon atoms, or an aryl group. group, vinyl group, halogenated alkyl group, or alkoxy group, n is an integer of 0 to 3, M is a silicon or titanium atom, R^1 is an alkyl group having 2 to 5 carbon atoms, R^2 and R^3 are Hydrogen atom or carbon number 1-1
0 represents an alkyl group or an aryl group, and R^4 represents a hydrogen atom or a methyl group. ] A curable composition containing an oxazolidine compound represented by (C) a compound containing an alkoxysilyl group, (D) an epoxy compound, and (E) a water scavenger. 4. (X) a polymer containing an alkoxysilyl group and either a carboxylic anhydride group or an epoxy group, (Y) a polymer containing an alkoxysilyl group and either a carboxylic anhydride group or an epoxy group A curable composition comprising: (B) an oxazolidine compound; and (E) a water scavenger. 5. A curable composition containing (X') a polymer containing an alkoxysilyl group, a carboxylic anhydride group, and an epoxy group, (B) an oxazolidine compound, and (E) a water scavenger.