JPH10316663A - Pyrazole-based compound and curing composition - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a new compound capable of crosslinking on heating at a relatively low temperature and being a base for curing compositions which give films excellent in both hardness and appearance when used as coatings. SOLUTION: This pyrazole compound is a compound expressed by formula I [R<1> is H or methyl; R<2> is CO, COOR<3> (R<3> is a 2-6C alkylene), a divalent group of formula II (R<4> and R<5> are H or methyl), COOCH2 CH2 OCONH-R<6> (R<6> is the divalent group derived by removing isocyanate groups in a diisocyanate compound); Q<1> and Q<2> are each H, methyl, RCONH, ROCO (R is an alkyl)]. The compound of formula I can be obtained, e.g. by reacting an isocyanate compound of formula III having a double bond with a pyrazole (derivative). E.g. a curing composition is obtained by using a copolymer, as a base resin, containing the compound of formula I and a polymerizable unsaturated compound having a hydroxyl group in the molecule as monomer components.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a polymerizable pyrazole compound and a curable composition using the compound.
More specifically, (1) a polymerizable pyrazole-based compound represented by the following general formula (I), which is a raw material of a thermosetting resin used for a paint, an adhesive, or the like; (2) a polymerizable pyrazole-based compound represented by the general formula (I) A curable composition containing a polymerizable pyrazole-based compound and a copolymer having a monomer component as a polymerizable unsaturated compound having a hydroxyl group, an amino group, or a carboxyl group in a molecule,
And (3) a curable composition containing a copolymer containing the compound represented by the general formula (I) as a monomer component and a polymer having a hydroxyl group, an amino group, or a carboxyl group in the molecule.

[0002]

[Description of Related Art] Acrylic monomer (co) polymer is widely used in paints, adhesives, etc. because of its excellent appearance, mechanical properties, weather resistance and the like. In this case, a solution obtained by dissolving or dispersing the polymer in a solvent is applied to a substrate,
Since the hardness, strength, durability and the like are insufficient only by evaporating the solvent, crosslinking is usually performed. Although various methods have been developed as a method of cross-linking, usually, a hydroxyl group, an amino group, a carboxyl group, etc. are included in the polymer, and a plurality of epoxy groups, carboxyl groups, isocyanato groups, etc. are included as a cross-linking agent. A method of reacting a compound is often employed.

[0003] Curing compositions containing a polyhydroxy compound and a polyisocyanate in which an active isocyanate group is blocked (protected) are also known. Examples of the blocking agent include 1,2,4-triazole and 3,3,4-triazole. 5-
Dimethylpyrazole, butanone oxime, acetoacetate, malonate diester and the like are used (JP-A-8-225630, JP-A-8-104726, JP-A-7-104726).
No. 304843). Further, the isocyanate group of 2-methacryloyloxyethyl isocyanate is blocked with a compound such as an alcohol, phenol, oxime, or lactam, and a copolymer of the obtained compound and methyl methacrylate or ethyl acrylate is blended with the polyester polyol. Compositions are also known (Ind. E
ng. Chem. Prod. Res. Dev, 1984, 23 , 586-590).

[0004]

However, these known crosslinking reaction systems have poor storage stability in a system in which the reaction easily occurs under mild conditions, so that the main agent and the curing agent (crosslinking agent) are used. ) Must be stored separately and mixed in a predetermined ratio immediately before use. This is troublesome, contradicts recent efforts to save labor, and has the disadvantage that the expected performance cannot be obtained if the mixing ratio is incorrect. On the other hand, a system having good storage stability requires a high temperature for the reaction, and has a problem that it is difficult to use when the substrate is not strong against heat, such as a case where the base material is a plastic such as polyolefin or ABS. Therefore, it cures under relatively mild conditions,
In addition, a cross-linking means having good storage stability without dividing into two liquids is required.

[0005]

Means for Solving the Problems The present inventors have conducted various studies to solve the above-mentioned problems, and as a result, have found that the general formula (I)

Embedded image [Wherein, R ¹ represents a hydrogen atom or a methyl group, R ² represents —CO—, —COOR ³ — (R ³ is an alkylene group having 2 to 6 carbon atoms), and formula (II).

Embedded image (R ⁴ and R ⁵ each independently represent a hydrogen atom or a methyl group.) Or —COOC
H ₂ CH ₂ OCONH—R ⁶ — (R ⁶ is a divalent group obtained by removing an isocyanato group from a diisocyanate compound), and Q ¹ and Q ² each independently represent a hydrogen atom,
Represents a methyl group, RCONH-, or ROCO- (R is an alkyl group). Or a polymer containing a polymerizable unsaturated compound having a hydroxyl group, an amino group, or a carboxyl group in a molecule as a monomer component, or a polymerizable pyrazole compound represented by the formula: A copolymer containing the compound represented by (I) as a monomer component and a hydroxyl group, an amino group,
Or, when using both polymers having a carboxyl group as a base resin, crosslinking occurs by heating at a relatively low temperature, and when used as a coating, it is found that a coating film excellent in both hardness and appearance is obtained, and the present invention It was completed.

That is, the present invention provides 1) a polymerizable pyrazole compound represented by the general formula (I), 2) a polymerizable pyrazole compound represented by the general formula (I), and a hydroxyl group or an amino group in the molecule. Or a curable composition containing a copolymer containing a polymerizable unsaturated compound having a carboxyl group as a monomer component, and 3) a polymerizable pyrazole compound represented by the general formula (I) as a monomer component. Provided is a curable composition containing a copolymer and a polymer having a hydroxyl group, an amino group, or a carboxyl group in a molecule.

Hereinafter, the present invention will be described in detail. Various methods for producing the polymerizable pyrazole-based compound represented by the general formula (I) used in the curable composition of the present invention can be considered, and are not particularly limited. The following general formula (III)

Embedded image (In the formula, R ¹ and R ² have the same meanings as in the case of the general formula (I).) A method of reacting an isocyanate compound having a double bond with pyrazole or a derivative thereof is convenient.

The compound represented by the general formula (III) includes, for example, 2-methacryloyloxyethyl isocyanate, methacryloyl isocyanate, m-isopropenyl-α, α-dimethylbenzyl isocyanate,
A 1: 1 reaction product of hydroxyethyl (meth) acrylate and a diisocyanate compound can be used.

The diisocyanate compound to be reacted with 2-hydroxyethyl (meth) acrylate includes, for example, 2,4- or 2,6-tolylene diisocyanate (TDI), 4,4'-diphenylmethane diisocyanate (MDI), Hexamethylene diisocyanate, 3,5,5-trimethyl-3-isocyanatomethylcyclohexyl isocyanate (IPDI), m- or p-xylylene diisocyanate (m- or p-X
DI), 4,4'-dicyclohexylmethane diisocyanate (H ₁₂ MDI), 1,3 or 1,4-bis (isocyanatomethyl) cyclohexane, Rijinji (or tri) isocyanate and the like can be used. Among these, from the availability of high-purity products and the ease of handling,
-Methacryloyloxyethyl isocyanate and m-isopropenyl-α, α-dimethylbenzyl isocyanate are particularly preferred, and 2-methacryloyloxyethyl isocyanate is most preferred from the viewpoint of reactivity.

Examples of the pyrazole or a derivative thereof to be reacted with the compound of the general formula (III) include various compounds such as unsubstituted pyrazole, 3,5-dimethylpyrazole, 3-acetylaminopyrazole and pyrazole-3,5-dicarboxylic acid diethyl ester. Can be used. However, in terms of availability (that is, economy), curability when this is used for a curable resin, and properties of the obtained cured product, 3,5-dimethyl Pyrazole is particularly preferred.

In the reaction, the pyrazole or a derivative thereof is heated to a melting point or higher to be melted, or dissolved or dispersed in an inert solvent, and the compound represented by the general formula (III) or the inert solvent is added thereto. Add the solution dissolved in. After the addition, the reaction is allowed to proceed for a while to complete the reaction. The ratio of pyrazole or a derivative thereof to the compound represented by the general formula (III) is theoretically 1:
Although it may be 1 (molar ratio), it is better to use pyrazole or a derivative thereof in an excess of 1 to 5% in order to facilitate the completion of the reaction. There is no merit even if it is used more than this, because it is uneconomical. On the other hand, if the amount is too small, it takes time to complete the reaction, or the reaction may not be completed in some cases.

As the inert solvent, those which do not react with the compound represented by the general formula (III) and preferably dissolve the pyrazole derivative are preferable. Examples thereof include toluene, xylene, ethyl acetate, n-butyl acetate, cyclohexanone and methyl isobutyl ketone. Are used. Some of these solvents may be used as a mixture. The reaction temperature varies depending on the type of the compound represented by the general formula (III), the presence or absence of a catalyst, and the like, but is preferably from about room temperature to about 120 ° C. If the temperature is too low, the reaction may be too slow, and if it is too high, gelation may occur due to polymerization of C = C (double bond). Further, since there is an upper limit of the conversion depending on the reaction temperature, when the progress of the reaction is stopped, it is necessary to gradually lower the temperature to complete the reaction.

It is desirable to add a polymerization inhibitor to the reaction system in order to prevent polymerization. Examples of the polymerization inhibitor include phenothiazine, p-methoxyphenol, 2,6
-Ditertiary butyl-4-methylphenol (BH
Commonly used ones such as T) can be used, but phenothiazine and / or BHT are particularly suitable in view of the polymerization inhibitory effect. The compounds of the formula (I) thus obtained are novel per se and are the subject of the present invention.

The compound represented by the general formula (I) obtained above is used as a base resin of a curable composition.
When a polymerization inhibitor is contained, it is not always necessary to remove it, and it can be used as it is.

In the curable composition of the present invention, as a base resin, a compound represented by the general formula (I) and a polymerizable unsaturated compound having a hydroxyl group, an amino group or a carboxyl group in the molecule as one monomer are used as one molecule. A copolymer containing a compound represented by the general formula (I) as a monomer component and a polymer having a hydroxyl group, an amino group or a carboxyl group in the molecule may be used. A thing may be used.

Examples of the polymer or copolymer having a hydroxyl group (hereinafter referred to as (co) polymer) include 2-hydroxyethyl (meth) acrylate, 2-hydroxyethyl vinyl ether, 4-hydroxybutyl vinyl ether and the like as a vinyl monomer component. Or a saponified product of a vinyl acetate (co) polymer, or a component composed of a component other than a vinyl monomer such as a polyester polyol, a polyether polyol, or an epoxy resin. You may.

As the (co) polymer having an amino group, 2
-Aminoethyl (meth) acrylate (co) polymer, polyallylamine, polyethyleneimine and the like. As the (co) polymer having a carboxyl group, a (co) polymer having a polymerizable unsaturated compound having a carboxyl group such as (meth) acrylic acid, crotonic acid, itaconic acid, and maleic acid as one of the monomer components, Examples include a terminal carboxyl group polyester and a polyamic acid.

Of these (co) polymers, vinyl (co)
Compounds belonging to the polymer include one or more vinyl polymerizable monomers in addition to the compound represented by the general formula (I) and a polymerizable unsaturated compound having a hydroxyl group, an amino group, or a carboxyl group in the molecule. Can be contained. Such monomers include (meth) acrylates such as methyl (meth) acrylate, ethyl (meth) acrylate, various butyl (meth) acrylates, 2-ethylhexyl (meth) acrylate, lauryl (meth) acrylate, and styrene. , Ethyl vinyl ether, various butyl vinyl ethers, cyclohexyl vinyl ether, trifluorochloroethylene,
Suitable ones are selected according to the glass transition temperature, solubility parameter value, and other properties of the polymer to be produced.

A copolymer containing, as a monomer component, a compound represented by the general formula (I) and a polymerizable unsaturated compound having a hydroxyl group, an amino group, or a carboxyl group in a molecule, or a compound represented by the general formula: In a composition comprising the compound represented by the formula (I) as a monomer component and a polymer having a hydroxyl group, an amino group, or a carboxyl group in the molecule, a compound represented by the general formula (I) and a hydroxyl group , Amino group or carboxyl group "is preferably from 0.1 to 10 in an equivalent ratio of (compound represented by formula (I)) / (total of hydroxyl group, amino group or carboxyl group). The equivalent ratio varies depending on the material of the base material and the properties of the intended paint or adhesive, but is generally 0.5 to 1.5.
Used in equivalent ratios of the order.

The curable composition of the present invention may optionally contain a catalyst. As the catalyst, tertiary amines such as triethylamine and triethylenediamine;
Tin compounds such as dibutyltin dilaurate are preferably used. The amount of catalyst used is 5% by weight of the total composition
The following is good. If it is too much, it is uneconomical and has adverse effects on coloring and other physical properties of the final product. Further, the composition may include a solvent. As the solvent, the above general formula (II
Solvents used in the reaction of the compound of I) with pyrazole or its derivatives are preferred. The composition produced in this manner is one-part, has good storage stability, and can be cured under mild conditions when used as a paint or adhesive. When the curable composition of the present invention is used as a paint or an adhesive, other components usually used as the paint or the adhesive composition can be blended. Such components include, for example, colorants, UV absorbers, antioxidants, leveling agents, and the like.

[0021]

EXAMPLES The present invention will be specifically described below with reference to synthesis examples of the compound represented by the general formula (I), polymerization examples thereof, and examples of the curable composition. It is not limited by.

Synthesis Example 1: Stirrer, thermometer, dropping funnel,
In a 100 ml four-necked round-bottomed flask equipped with a reflux condenser, 19.61 g of 3,5-dimethylpyrazole (100%
(The same, hereinafter the same, 0.204 mol) and 0.3 g of BHT were charged, immersed in an oil bath, the temperature was raised to 110 ° C., and the contents were melted. Here, 31.03 g of 2-methacryloyloxyethyl isocyanate (Karenz MOI, manufactured by Showa Denko KK)
(0.2 mol) was added dropwise over 40 minutes. Since the internal temperature rises due to the dropping, the dropping speed was adjusted so as not to exceed 115 ° C. After the completion of the dropwise addition, the mixture was further heated for 1 hour.
The absorption around 2270 cm ^-1 disappears and 1720 based on C = O group.
Since the absorption at 11750 cm ⁻¹ increased, the reaction was terminated and cooled slowly. A clear, pale yellow liquid product was obtained at room temperature. FIG. 1 shows the IR spectrum and FIG. 2 shows the ¹ H-NMR spectrum.

Synthesis Example 2: m-Isopropenyl-α, instead of 2-methacryloyloxyethyl isocyanate
When the reaction was carried out in the same manner as in Synthesis Example 1 except that 40.2 g of α-dimethylbenzyl isocyanate was used and the heating time after completion of the dropwise addition was 3 hours, the absorption based on the NCO group in the IR spectrum did not change. So 20 per hour
When the temperature was lowered to 50 ° C. at a rate of 50 ° C. and then left to cool to room temperature, the IR spectrum was based on NCO groups.
The absorption around 70 cm ^-1 disappears, and 1720-
A product with increased absorption at 1750 cm ^-1 was obtained.

Synthesis Example 3 In the same experiment as in Synthesis Example 1, instead of 2-methacryloyloxyethyl isocyanate, 22.2 g of methacryloyl isocyanate dissolved in 30 g of dehydrated toluene was added dropwise over 1 hour. When addition was measured for IR spectrum from the end after 10 minutes, stop the reaction absorption around 2200 cm ^-1 based on NCO group disappeared and the absorption of 1720～1750Cm ^-1 based on C = O group is increased Then, the mixture was gradually cooled to obtain a product.

Synthesis Example 4: Stirrer, thermometer, dropping funnel,
In a 500 ml four-necked round bottom flask equipped with a reflux condenser, 6,6.6 g of 3,5,5-trimethyl-3-isocyanatomethylcyclohexyl isocyanate (IPDI), BH
0.5 g of T and 100 g of cyclohexanone
After the temperature was raised to 100 ° C., 39 g of 2-hydroxyethyl methacrylate was added dropwise over 2 hours. 1 more after dropping
Stirring was continued at that temperature for an hour, and then 7.8 g of 2-hydroxyethyl methacrylate was added dropwise over a further 25 minutes.
Next, 23.5 g of 3,5-dimethylpyrazole was charged into a 300 ml four-necked round bottom flask equipped with a stirrer, a thermometer, a dropping funnel, and a reflux condenser.
The temperature was raised to 0 ° C. to melt the contents. To this, 178 g of the product solution obtained above was dropped over 40 minutes. After completion of the dropwise addition was continued for 2 hours as it warmed, the absorption disappeared in the vicinity of 2270 cm ^-1 based on the NCO group in the IR spectrum, the absorption of 1720～1750Cm ^-1 based on C = O group is increased, the reaction Was completed, and the mixture was gradually cooled to obtain a product.

Synthesis Example 5 Reaction was carried out in the same manner as in Synthesis Example 1 except that pyrazole-3,5-dicarboxylic acid diethyl ester 43.3 g was used in place of 3,5-dimethylpyrazole, and was around 2270 cm ^-1 based on NCO groups. Absorption disappears,
A pale yellow, clear liquid product having an increased absorption at 1720-1750 cm ^-1 based on the C ＝ O group was obtained.

Polymerization Example 1: Copolymerization of compound represented by formula (I) Cyclohexanone 7 was placed in a 300 ml four-necked round bottom flask equipped with a stirrer, thermometer, dropping funnel and reflux condenser.
After charging 0 g and replacing the inside of the system with nitrogen, the system was placed in an oil bath and the temperature was raised to 70 ° C. Here, 20 g of the product obtained in Synthesis Example 1, 8 g of styrene, and methyl methacrylate 20
g, n-butyl acrylate 40 g, 2-hydroxyethyl methacrylate 10 g, 2,2'-azobis (4-
A monomer mixture of 8 g of (methoxy-2,4-dimethylvaleronitrile) was added dropwise over 3 hours, and after completion, what had adhered to the inner wall of the dropping funnel was washed into the flask with 2 g of cyclohexanone. Then, a solution prepared by dissolving 0.5 g of 2,2'-azobis (4-methoxy-2,4-dimethylvaleronitrile) in 6 g of cyclohexanone was added dropwise, and the substance attached to the inner wall of the dropping funnel was washed into the flask with 1.5 g of cyclohexanone. . After continuing heating for 1 hour as it was, it was cooled to room temperature to obtain a copolymer solution (A).

Polymerization Example 2: Copolymerization of the compound represented by the general formula (I) 40 g of the compound obtained by the method of Synthesis Example 1, 40 g of methyl methacrylate, 40 g of n-butyl acrylate, The same operation as in Polymerization Example 1 was carried out except that the mixed solution was composed of 8 g of 2'-azobis (4-methoxy-2,4-dimethylvaleronitrile) to obtain a copolymer solution (B).

Polymerization Example 3: Preparation of a polymer having a hydroxyl group and a carboxyl group A monomer mixture to be dropped was mixed with 16 g of styrene, 40 g of n-butyl acrylate, 20 g of 2-hydroxyethyl methacrylate, 10 g of acrylic acid, 2,2'-azobis. (4-methoxy-2,4-dimethylvaleronitrile) 8
The same operation as in Polymerization Example 1 was performed except that the mixed solution was made of g, to obtain a copolymer solution (C).

Example 1 Formation of Coating Film Copolymer solution (A) was coated with an applicator to 50 μm.
m on a glass plate and air-dried for 10 minutes.
It was baked for 20 minutes in a hot air drier at ℃. Then, it was taken out, cooled to room temperature, and scratched with a HB pencil. No scratch was found. Further, rubbing was performed 100 times with absorbent cotton containing methyl ethyl ketone, but the coating film was not peeled off.

Example 2: Coating film formation The copolymer solution (B) and the copolymer solution (C) were mixed at a ratio of 1.2: 1.
(Weight ratio). When the same treatment as in Example 1 was performed using the obtained mixed solution, no scratch was found even when scratched with a HB pencil. In addition, the coating film was not peeled off by rubbing 100 times with absorbent cotton containing methyl ethyl ketone. On the other hand, the mixed solution remained liquid even after being left for one month.

Comparative Example 1 Polymerization was carried out in the same manner as in Polymerization Example 1 except that the product obtained in Synthesis Example 1 was not used. The same treatment as in Example 1 was performed using the obtained copolymer solution, but the coating film was soft and scratched with HB pencil. When rubbed with absorbent cotton containing methyl ethyl ketone, the coating film was melted.

Comparative Example 2: The monomer solution to be dropped was 2-
20 g of methacryloyloxyethyl isocyanate, 8 g of styrene, 20 g of methyl methacrylate, 40 g of n-butyl acrylate, 10 g of 2-hydroxyethyl methacrylate, 2,2′-azobis (4-methoxy-2,
The same operation as in Polymerization Example 1 was carried out except that the mixed solution was composed of 8 g of 4-dimethylvaleronitrile). As a result, a gel was formed and a copolymer solution was not obtained.

[0034]

The present invention relates to a novel polymerizable pyrazole compound represented by the general formula (I), a polymerizable pyrazole compound represented by the general formula (I) and a hydroxyl group, an amino group or a carboxyl group in the molecule. A curable composition containing a copolymer containing a polymerizable unsaturated compound having a group as a monomer component, and a copolymer containing a compound represented by the general formula (I) as a monomer component and a hydroxyl group or an amino group in the molecule Or a curable composition containing a polymer having a carboxyl group. The curable composition according to the present invention has good storage stability even without being divided into two liquids, causes crosslinking by heating at a relatively low temperature, and has excellent hardness and appearance when used as a paint or an adhesive. Give the membrane.

[Brief description of the drawings]

FIG. 1 is an IR spectrum of the compound obtained in Synthesis Example 1.

FIG. 2 is a ¹ H-NMR spectrum of the compound obtained in Synthesis Example 1.

Continued on the front page (51) Int.Cl. ⁶ Identification code FI C08F 290/00 C08F 290/00 299/00 299/00 (72) Inventor Masashi Hatanaka 5-1 Ogimachi, Kawasaki-ku, Kawasaki-shi, Kanagawa Prefecture Showa Denko shares (72) Inventor Muneyo Kihara 5-1 Ogimachi, Kawasaki-ku, Kawasaki-shi, Kanagawa Prefecture, Japan Showa Denko Co., Ltd.

Claims (4)

[Claims] 1. A compound of the general formula (I) [Wherein, R ¹ represents a hydrogen atom or a methyl group, R ² represents —CO—, —COOR ³ — (R ³ is an alkylene group having 2 to 6 carbon atoms), and the formula (II): Formula 2 (R ⁴ and R ⁵ each independently represent a hydrogen atom or a methyl group.) Or —COOC
H ₂ CH ₂ OCONH—R ⁶ — (R ⁶ is a divalent group obtained by removing an isocyanato group from a diisocyanate compound), and Q ¹ and Q ² each independently represent a hydrogen atom,
Represents a methyl group, RCONH-, or ROCO- (R is an alkyl group). ] The compound shown by these. 2. The compound according to claim 1, wherein Q ¹ and Q ² are both methyl groups. 3. A copolymer comprising a compound represented by the formula (I) according to claim 1 and a polymerizable unsaturated compound having a hydroxyl group, an amino group or a carboxyl group in a molecule as a monomer component. Curable composition containing. 4. A curing method comprising a copolymer containing the compound represented by the general formula (I) according to claim 1 as a monomer component and a polymer having a hydroxyl group, an amino group, or a carboxyl group in the molecule. Composition.