JP2006104215A - Pyrazole-based compound and curable composition - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a curable composition containing an acrylic (co)polymer as a base resin which cures under relatively mild conditions and has good storage stability without being divided into two packs, and a compound which comes to its base resin raw material. <P>SOLUTION: The novel polymerizable pyrazole-based compound is represented by formula (I). The curable composition comprises a copolymer comprising the compound represented by formula (I) and a polymerizable unsaturated compound having a hydroxy group, an amino group or a carboxy group in the molecule as monomer components. The curable composition comprises a copolymer having the compound represented by formula (I) as a monomer component and a polymer having a hydroxy group, an amino group or a carboxy group in the molecule. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a polymerizable pyrazole compound and a curable composition using the compound. More specifically, (1) a polymerizable pyrazole compound represented by the following general formula (I) used as a raw material for a thermosetting resin used in paints, adhesives, etc., (2) represented by general formula (I) A curable composition comprising a copolymer comprising a polymerizable pyrazole compound and a polymerizable unsaturated compound having a hydroxyl group, an amino group, or a carboxyl group in the molecule as monomer components; and (3) the general formula (I) And a polymer having a hydroxyl group, an amino group, or a carboxyl group in the molecule.

  Since (co) polymers of acrylic monomers are excellent in appearance, mechanical properties, weather resistance, etc., they are widely used in paints, adhesives and the like. In this case, it is usual to crosslink because a solution in which a polymer is dissolved or dispersed in a solvent is applied to a substrate and the solvent is evaporated, resulting in insufficient hardness, strength, durability and the like. Various methods of crosslinking have been developed. Usually, a polymer contains a hydroxyl group, an amino group, a carboxyl group, etc., and a crosslinking agent contains a plurality of epoxy groups, carboxyl groups, isocyanate groups, etc. A method of reacting a compound is often employed.

Moreover, the hardening composition which mix | blended the polyhydroxy compound and the polyisocyanate which blocked the active isocyanate group (protection) is known, As a blocking agent, for example, 1,2,4-triazole, 3,5-dimethyl is known. Pyrazole, butanone oxime, acetoacetic acid ester, malonic acid diester and the like are used (Japanese Patent Laid-Open No. 8-225630; Japanese Patent Laid-Open No. 8-104726; Japanese Patent Laid-Open No. 7-304843). Patent document 3 etc.). Furthermore, the isocyanate group of 2-methacryloyloxyethyl isocyanate is blocked with a compound such as alcohol, phenol, oxime, or lactam, and a copolymer of the resulting compound and methyl methacrylate or ethyl acrylate is blended with polyester polyol. Such a composition is also known (Ind. Eng. Chem. Prod. Res. Dev, 1984, 23 , 586-590; Non-Patent Document 1).
JP-A-8-225630 Japanese Patent Laid-Open No. 8-104726 Japanese Unexamined Patent Publication No. 7-304843 Ind.Eng.Chem.Prod.Res.Dev, 1984,23,586-590

  However, in these conventionally known crosslinking reaction systems, since the storage stability is poor in a system in which a reaction easily occurs under mild conditions, the main agent and the curing agent (crosslinking agent) are stored separately, It must be mixed in a certain proportion immediately before use. This is time consuming and contrary to the recent labor-saving trend, and has the disadvantages that the performance expected when the mixing ratio is wrong is not achieved. On the other hand, in a system with good storage stability, a high temperature is required for the reaction, and there is a problem that it is difficult to use if the substrate is not resistant to heat, such as a plastic such as polyolefin or ABS. Therefore, there is a need for a crosslinking means that cures under relatively mild conditions and has good storage stability without being divided into two liquids.

〔式中、Ｒ¹は水素原子またはメチル基を表わし、Ｒ²は−ＣＯ−、−ＣＯＯＲ³−（Ｒ³は、炭素原子数２〜６のアルキレン基である。）、式（II）

（Ｒ⁴およびＲ⁵は、各々独立して水素原子またはメチル基を表わす。）で示される二価の基、または−ＣＯＯＣＨ₂ＣＨ₂ＯＣＯＮＨ−Ｒ⁶−（Ｒ⁶はジイソシアネート化合物からイソシアナト基を除いた二価の基である。）を表わし、Ｑ¹およびＱ²はそれぞれ独立して、水素原子、メチル基、ＲＣＯＮＨ−、またはＲＯＣＯ−（Ｒはアルキル基である。）を表わす。〕で示される新規な重合性ピラゾール系化合物と、分子内に水酸基、アミノ基、またはカルボキシル基を持つ重合性不飽和化合物とをモノマー成分として含む共重合体をベース樹脂として用いるか、あるいは一般式（Ｉ）で示される化合物をモノマー成分として含む共重合体と分子内に水酸基、アミノ基、またはカルボキシル基を持つ重合体の両方をベース樹脂として用いると、比較的低温で加熱することにより架橋が起こり、塗料として用いるときは硬度、外観共に優れた塗膜を与えることを見出し、本発明を完成させるに至った。 As a result of various studies to solve the above problems, the present inventors have found that the compounds of the general formula (I)

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

(R ⁴ and R ⁵ each independently represents a hydrogen atom or a methyl group), or —COOCH ₂ CH ₂ OCONH—R ⁶ — (R ⁶ represents an isocyanate group from a diisocyanate compound. Q ¹ and Q ² each independently represents a hydrogen atom, a methyl group, RCONH—, or ROCO— (wherein R is an alkyl group). Or a copolymer containing a polymerizable unsaturated compound having a hydroxyl group, an amino group, or a carboxyl group in the molecule as a monomer component, or a general formula When both a copolymer containing the compound represented by (I) as a monomer component and a polymer having a hydroxyl group, an amino group, or a carboxyl group in the molecule are used as a base resin, crosslinking is caused by heating at a relatively low temperature. As a result, it was found that when used as a paint, a coating film excellent in both hardness and appearance was obtained, and the present invention was completed.

That is, the present invention relates to 1) a polymerizable pyrazole compound represented by the general formula (I),
2) Curability containing a copolymer containing a polymerizable pyrazole 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 monomer components. And a curable composition comprising 3) a copolymer having the polymerizable pyrazole 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. A composition is provided.

  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 polymerizable compound having a hydroxyl group, an amino group, or a carboxyl group in the molecule. A curable composition containing a copolymer containing an unsaturated compound as a monomer component, and a copolymer containing a compound represented by formula (I) as a monomer component and a hydroxyl group, amino group, or carboxyl group in the molecule The present invention provides a curable composition containing a polymer having the same. The curable composition according to the present invention has good storage stability even if it is not divided into two liquids, and crosslinking occurs when heated at a relatively low temperature. When used as a paint or an adhesive, it has excellent hardness and appearance. Give a membrane.

（式中、Ｒ¹およびＲ²は一般式（Ｉ）の場合と同じ意味を表わす。）で示される二重結合を有するイソシアネート化合物とピラゾールまたはその誘導体を反応させる方法が便利である。 The present invention will be described in detail below. Various methods for producing the polymerizable pyrazole compound represented by the general formula (I) used in the curable composition of the present invention are conceivable and are not particularly limited, but are produced industrially, for example. The following general formula (III)

(Wherein R ¹ and R ² represent the same meaning as in the general formula (I).) A method of reacting an isocyanate compound having a double bond with pyrazole or a derivative thereof is convenient.

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

Here, as the diisocyanate compound to be reacted with 2-hydroxyethyl (meth) acrylate, 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-XDI), 4,4′-dicyclohexylmethane diisocyanate (H ₁₂ MDI) 1,3- or 1,4-bis (isocyanatomethyl) cyclohexane, lysine di (or tri) isocyanate and the like can be used. Among these, 2-methacryloyloxyethyl isocyanate and m-isopropenyl-α, α-dimethylbenzyl isocyanate are particularly preferred from the viewpoint of easy availability and handling of high-purity products, and 2-methacryloyl from the viewpoint of reactivity. Most preferred is oxyethyl isocyanate.

  Examples of pyrazole or derivatives thereof to be reacted with the compound of the general formula (III) include various types such as unsubstituted pyrazole, 3,5-dimethylpyrazole, 3-acetylaminopyrazole, pyrazole-3,5-dicarboxylic acid diethyl ester. Although it can be used, 3,5-dimethylpyrazole is particularly preferable in terms of easy availability (that is, economy), curability when used for a curable resin, properties of the obtained cured product, and the like. preferable.

  In the reaction, pyrazole or a derivative thereof is heated to a melting point or higher and melted, or dissolved or dispersed in an inert solvent, and this is dissolved in a compound represented by the general formula (III) or an inert solvent. Add the solution. After the addition is complete, react for a while to complete the reaction. The ratio of pyrazole or a derivative thereof to the compound represented by the general formula (III) may theoretically be 1: 1 (molar ratio). However, in order to facilitate the completion of the reaction, pyrazole or a derivative thereof is 1 to 5 It is better to use in% excess. Even if it is used in excess, it is uneconomical and has no merit. On the other hand, if the amount is too small, it may take time to complete the reaction or 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. For example, toluene, xylene, ethyl acetate, n-butyl acetate, cyclohexanone, methyl isobutyl ketone and the like are used. It is done. Further, some of these solvents may be mixed and used. The reaction temperature varies depending on the type of the compound represented by the general formula (III) and the presence or absence of a catalyst, but is preferably from room temperature to about 120 ° C. If the temperature is too low, the reaction will 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 rate depending on the reaction temperature, when the progress of the reaction stops, it is necessary to gradually lower the temperature to complete it.

  It is desirable to add a polymerization inhibitor to the reaction system in order to prevent polymerization. As the polymerization inhibitor, commonly used ones such as phenothiazine, p-methoxyphenol, 2,6-ditertiarybutyl-4-methylphenol (BHT) can be used, and in particular, phenothiazine and / or BHT is used. Suitable for preventing polymerization. The compound represented by the general formula (I) thus obtained is novel per se and is 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. Even when a polymerization inhibitor is included, it is not always necessary to remove it, and it can be used as it is.

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

  As a polymer or copolymer having a hydroxyl group (hereinafter referred to as (co) polymer), 2-hydroxyethyl (meth) acrylate, 2-hydroxyethyl vinyl ether, 4-hydroxybutyl vinyl ether or the like is one of the vinyl monomer components. May be used, or a saponified product of vinyl acetate (co) polymer, and further comprising components other than vinyl monomers such as polyester polyol, polyether polyol, epoxy resin, etc. .

  Examples of the (co) polymer having an amino group include 2-aminoethyl (meth) acrylate (co) polymer, polyallylamine, and polyethyleneimine. 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 terminal carboxyl group polyester and polyamic acid.

  Among these (co) polymers, those belonging to the vinyl (co) polymer are compounds represented by the general formula (I) and polymerizable unsaturated compounds having a hydroxyl group, an amino group, or a carboxyl group in the molecule. In addition, one or more kinds of vinyl polymerizable monomers can be contained as a monomer component. Such monomers include methyl (meth) acrylate, ethyl (meth) acrylate, various butyl (meth) acrylates, 2-ethylhexyl (meth) acrylate, (meth) acrylic esters such as lauryl (meth) acrylate, styrene , Ethyl vinyl ether, various butyl vinyl ethers, cyclohexyl vinyl ether, trifluorochloroethylene, vinyl acetate, etc., and the appropriate one is selected depending on the glass transition temperature, solubility parameter value, and other properties of the polymer to be produced. The

  In a copolymer containing 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 a monomer component, or the general formula (I) In the composition used in combination with the monomer component as a monomer component and a polymer having a hydroxyl group, amino group, or carboxyl group in the molecule, “a compound represented by the general formula (I)” and “hydroxyl group, amino group” The “or carboxyl group” is an equivalent ratio of (compound represented by the general formula (I)) / (total of hydroxyl group, amino group, or carboxyl group), preferably 0.1 to 10. The equivalent ratio varies depending on the material of the base material and the properties of the target paint or adhesive, but is generally used at an equivalent ratio of about 0.5 to 1.5.

  In some cases, the curable composition of the present invention may contain a catalyst. As the catalyst, tertiary amines such as triethylamine and triethylenediamine and tin compounds such as dibutyltin dilaurate are preferably used. The amount of the catalyst used is preferably 5% by weight or less of the entire composition. Excessive amounts are not economical and can adversely affect the color and other physical properties of the final product. The composition may contain a solvent. As the solvent, a solvent used in the reaction of the compound of the above general formula (III) with pyrazole or a derivative thereof is preferable. The composition produced in this way is one-part and has good storage stability and can be cured under mild conditions when used as a paint or adhesive. When using the curable composition of this invention as a coating material or an adhesive agent, the other component normally used can be mix | blended as a coating material or an adhesive composition. Examples of such components include colorants, UV absorbers, antioxidants, leveling agents and the like.

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

Synthesis example 1:
In a 100 ml four-necked round bottom flask equipped with a stirrer, thermometer, dropping funnel and reflux condenser, 19.61 g of 3,5-dimethylpyrazole (100% conversion, the same applies below, 0.204 mol) and 0.3 g of BHT were added. The contents were charged and immersed in an oil bath, the temperature was raised to 110 ° C., and the contents were melted. To this, 31.03 g (0.2 mol) of 2-methacryloyloxyethyl isocyanate (Karenz MOI, Showa Denko KK) was added dropwise over 40 minutes. Since the internal temperature increased due to the dropping, the dropping speed was adjusted so as not to exceed 115 ° C. When the heating was continued for 1 hour after the completion of the dropping, the absorption near 2270 cm ⁻¹ based on the NCO group disappeared in the IR spectrum, and the absorption at 1720 to 1750 cm ⁻¹ based on the C═O group increased. Finished and gradually cooled. A light yellow transparent liquid product was obtained at room temperature. The IR spectrum is shown in FIG. 1, and the ¹ H-NMR spectrum is shown in FIG.

Synthesis example 2:
The reaction was conducted in the same manner as in Synthesis Example 1 except that 40.2 g of m-isopropenyl-α, α-dimethylbenzyl isocyanate was used instead of 2-methacryloyloxyethyl isocyanate, and the heating time after completion of dropping was changed to 3 hours. However, the absorption based on the NCO group no longer changes in the IR spectrum. Therefore, when the temperature was lowered to 50 ° C. at a rate of 20 ° C. per hour and then left to lower to room temperature, absorption near 2270 cm ⁻¹ based on the NCO group disappeared in the IR spectrum, and based on the C═O group A product with increased absorption between 1720 and 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 the IR spectrum was measured 10 minutes after the completion of the dropping, the absorption near 2200 cm ⁻¹ based on the NCO group disappeared, and the absorption at 1720 to 1750 cm ⁻¹ based on the C═O group increased, so the reaction was terminated. The product was obtained by slow cooling.

Synthesis Example 4:
A 500 ml four-necked round bottom flask equipped with a stirrer, thermometer, dropping funnel and reflux condenser was charged with 6,6.6 g of 3,5,5-trimethyl-3-isocyanatomethylcyclohexyl isocyanate (IPDI) and 0.5 g of BHT. , And 100 g of cyclohexanone were added, and after raising the temperature to 100 ° C., 39 g of 2-hydroxyethyl methacrylate was added dropwise over 2 hours. Stirring was continued at that temperature for 1 hour after the completion of the dropping, and then 7.8 g of 2-hydroxyethyl methacrylate was further added dropwise over 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, and placed in an oil bath to raise the temperature to 110 ° C. Thawed. The product solution 178g obtained above was dripped here over 40 minutes. When heating was continued for 2 hours after completion of the dropping, the absorption near 2270 cm ⁻¹ based on the NCO group disappeared in the IR spectrum, and the absorption at 1720 to 1750 cm ⁻¹ based on the C═O group increased. And the product was obtained by slow cooling.

Synthesis Example 5:
The reaction was carried out in the same manner as in Synthesis Example 1 except that 43.3 g of pyrazole-3,5-dicarboxylic acid diethyl ester was used instead of 3,5-dimethylpyrazole, and absorption near 2270 cm ⁻¹ based on the NCO group disappeared. A pale yellow transparent liquid product with increased absorption of 1720-1750 cm ⁻¹ based on ═O groups was obtained.

Polymerization Example 1: Copolymerization of compound represented by general formula (I) 70 g of cyclohexanone was charged into a 300 ml four-necked round bottom flask equipped with a stirrer, thermometer, dropping funnel and reflux condenser, and the system was filled with nitrogen. Was replaced with 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, 20 g of methyl methacrylate, 40 g of n-butyl acrylate, 10 g of 2-hydroxyethyl methacrylate, 2,2′-azobis (4-methoxy-2,4-dimethyl) (Valeronitrile) 8 g of monomer mixture was dropped over 3 hours, and after the completion, the one adhering to the inner wall of the dropping funnel was washed into the flask with 2 g of cyclohexanone. Next, 0.5 g of 2,2′-azobis (4-methoxy-2,4-dimethylvaleronitrile) dissolved in 6 g of cyclohexanone was dropped, and the one adhering to the inner wall of the dropping funnel was washed into the flask with 1.5 g of cyclohexanone. . The mixture was further heated for 1 hour and then cooled to room temperature to obtain a copolymer solution (A).

Polymerization Example 2: Copolymerization of the compound represented by the general formula (I) The monomer mixture liquid to be added dropwise was prepared by the method of Synthesis Example 1 with 40 g of the compound, 40 g of methyl methacrylate, 40 g of n-butyl acrylate, 2,2′- A copolymer solution (B) was obtained in the same manner as in Polymerization Example 1 except that the mixture was composed of 8 g of azobis (4-methoxy-2,4-dimethylvaleronitrile).

Polymerization Example 3: Preparation of a polymer having a hydroxyl group and a carboxyl group A monomer mixture solution to be dropped was prepared by adding 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- A copolymer solution (C) was obtained in the same manner as in Polymerization Example 1 except that the mixture was composed of 8 g of methoxy-2,4-dimethylvaleronitrile).

Example 1: Formation of coating film Copolymer solution (A) was applied to a glass plate with a thickness of 50 µm using an applicator, air-dried for 10 minutes, and baked in a hot air dryer at 120 ° C for 20 minutes. Next, it was taken out, cooled to room temperature, and scratched with an HB pencil. Moreover, although it rubbed 100 times with the absorbent cotton containing methyl ethyl ketone, the coating film did not peel off.

Example 2: Formation of coating film Copolymer solution (B) and copolymer solution (C) were mixed at a ratio of 1.2: 1 (weight ratio). When the same process as Example 1 was performed using the obtained liquid mixture, even if it scratched with the pencil of HB, it was not damaged. Moreover, although it rubbed 100 times with the absorbent cotton containing methyl ethyl ketone, the coating film did not peel off. On the other hand, the mixed solution remained liquid even after being left for one month.

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

Comparative Example 2:
The monomer solution to be added dropwise was 20 g of 2-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-2,4-dimethyl). Except for using a mixed solution consisting of 8 g of valeronitrile), the same operation as in Polymerization Example 1 was performed.

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

Claims (7)

Formula (I)

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

(R ⁴ and R ⁵ each independently represents a hydrogen atom or a methyl group) or —COOCH ₂ CH ₂ OCONH—R ⁶ — (R ⁶ is a group represented by the formula (IV)

Is a divalent group selected from the group represented by: Q ¹ and Q ² each independently represent a hydrogen atom, a methyl group, RCONH—, or ROCO— (wherein R is an alkyl group), except when each is a hydrogen atom. . ] The compound shown. The compound according to claim 1, wherein Q ¹ and Q ² are both methyl groups. The compound according to claim 2, wherein R ² is —COO (CH ₂ ) ₂ —.   Copolymer comprising the compound represented by the general formula (I) according to any one of claims 1 to 3 and a polymerizable unsaturated compound having a hydroxyl group, an amino group, or a carboxyl group in a molecule as monomer components. A curable composition containing a coalescence.   Hardened | cured material obtained by hardening | curing the curable composition of Claim 4. General formula (III)

(In the formula, R ¹ and R ² represent the same meaning as in the general formula (I).) A method of reacting an isocyanate compound having a double bond and a pyrazole derivative, wherein an inert solvent is used. The method for producing a compound according to claim 1, wherein the pyrazole derivative is heated to a melting point or higher without being used, and the isocyanate compound is added and reacted with stirring. The method for producing a compound according to claim 6, wherein the pyrazole derivative is 3,5-dimethylpyrazole.

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