JP2002249578A - Heat-curable composition - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a heat-curable composition showing an excellent heat curing rate, containing a compound having an oxetane ring and an acid anhydride. SOLUTION: The purpose is accomplished by using the heat-curable composition comprising a compound having an oxetane ring, an acid anhydride and zinc carboxylate or acetylacetonate, and a heat curing accelerator comprising zinc carboxylate or acetylacetonate.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a thermosetting composition containing a compound having an oxetane ring and an acid anhydride.
The thermosetting composition has excellent mechanical properties (tensile strength, hardness, etc.), electrical properties (insulating properties, etc.), adhesiveness, heat resistance, moisture resistance, chemical resistance, due to the curing reaction (intermolecular crosslinking). It forms a cured product with an insoluble and infusible three-dimensional structure that shows properties, such as paints, coatings, adhesives, electrical insulating materials, sealing materials, laminates, concrete structures as substitutes for epoxy resins It can be expected to be used in fields such as material repair and bonding of reinforcing steel plates.

[0002]

2. Description of the Related Art Thermosetting compositions containing a compound having an oxetane ring and an acid anhydride include a compound (A) having 1 to 4 oxetane rings in the molecule, a functional acid anhydride or a free acid anhydride. Thermosetting composition comprising the product (B) and the quaternary onium salt (C) is known (JP-A-11-607).
02 publication). However, this composition was not satisfactory in terms of heat cure rate.

[0003]

SUMMARY OF THE INVENTION An object of the present invention is to provide a thermosetting composition containing an oxetane ring-containing compound and an acid anhydride, which has an excellent thermosetting rate.

[0004]

An object of the present invention is to provide a compound having an oxetane ring, an acid anhydride, a thermosetting composition comprising a zinc carboxylate or acetylacetonate, and a zinc carboxylate. Alternatively, the problem is solved by a thermosetting accelerator containing acetylacetonate.

[0005]

BEST MODE FOR CARRYING OUT THE INVENTION [Compound Having Oxetane Ring]
In the thermosetting composition of the present invention, the compound having an oxetane ring is preferably a compound having 1 to 4 oxetane rings in the molecule. Compounds having one to four oxetane rings in the molecule include compounds having one oxetane ring in the molecule, compounds having two oxetane rings in the molecule, and three or four oxetane rings in the molecule May be used alone or in combination.

[0006] Of the compounds having one to four oxetane rings in the molecule, the compound having one oxetane ring in the molecule is preferably a compound represented by the chemical formula (1). R ¹ represents a hydrogen atom or a linear or branched alkyl group having 1 to 6 carbon atoms.)

[0007]

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As the compound having one oxetane ring in the molecule, specifically, 3-hydroxymethyloxetane, 3-methyl-3-hydroxymethyloxetane,
3- such as 3-ethyl-3-hydroxymethyloxetane
Alkyl-3-hydroxymethyloxetane is preferable, and among them, 3-methyl-3-hydroxymethyloxetane and 3-ethyl-3-hydroxymethyloxetane are preferable. In addition, as said linear or branched C1-C6 alkyl group, methyl group, ethyl group, n-propyl group, i-propyl group, n-butyl group,
Examples thereof include an i-butyl group and a sec-butyl group.

Among the compounds having two oxetane rings in the molecule, a compound represented by the chemical formula (2) is preferably exemplified (wherein, R ² is the same group as R ¹ ,
R ³ represents a divalent group. ).

[0010]

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[0011] The divalent radical ^{R 3} of the ethylene group, trimethylene group, tetramethylene group, pentamethylene group, hexamethylene group, 1,2-propylene group, 1,
C1-C12 linear or branched alkylene groups such as 2-butylene group, 1,3-butylene group, and 2,3-butylene group; and C1-C12 alkyl groups such as propenylene group and butenylene group.
12 linear or branched alkenylene groups,

A divalent aromatic hydrocarbon group represented by the chemical formula (3) (wherein R ⁴ is a hydrogen atom, a linear or branched alkyl group having 1 to 4 carbon atoms, A straight-chain or branched alkoxy group, a halogen atom, a nitro group, a cyano group, a mercapto group, a straight-chain or branched alkoxycarbonyl group having 1 to 4 carbon atoms, a carboxyl group or a straight-chain having 1 to 5 carbon atoms. A chain or branched N-alkylcarbamoyl group);

[0013]

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Or a divalent aromatic hydrocarbon group represented by the chemical formula (4) (wherein R ⁵ represents a —O— group, a —S— group, a —C
H ₂ — group, —NH— group, —SO— group, —SO ₂ — group, —
Represents a C (CF ₃ ) ₃ — group or a —C (CH ₃ ) ₃ — group. )

[0015]

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A carbonyl group or a divalent alkylene group containing a carbonyl group represented by the chemical formula (5)
Represents an integer of 1 to 20. ), A divalent alicyclic hydrocarbon group containing a carbonyl group represented by the chemical formula (6),
A divalent aromatic hydrocarbon group containing a carbonyl group represented by the chemical formula (7),

[0017]

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[0018]

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[0019]

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A divalent group represented by the chemical formula (8) (wherein
Y is an optionally substituted linear or branched C1-C12 alkylene group, or an optionally substituted divalent alicyclic hydrocarbon group represented by the following formula, Or,
It represents any of the optionally substituted divalent arylene groups represented by the following formulas. ) And the like.

[0021]

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[0022]

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[0023]

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Among the compounds having two oxetane rings in the molecule, those in which R ² is a methyl group or an ethyl group in chemical formula (2) are preferable, and R ³ is a compound having 1 to 12 carbon atoms. A linear alkylene group or a divalent aromatic hydrocarbon group represented by the chemical formula (3) wherein R ⁴ is a hydrogen atom is preferable. Specifically, for example, the following compounds are preferred.

[0025]

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As the compound having 3 to 4 oxetane rings in the molecule, a compound represented by the chemical formula (9) is preferably exemplified (wherein, R ⁵ is the same group as R ¹ described above;
R ⁶ is a trivalent or tetravalent hydrocarbon group which may be substituted, a group represented by the formula (10), or a compound represented by the formula (1)
Represents a group represented by 1). m is 3 or 4. ).

[0027]

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[0028]

Embedded image (Wherein, Z ¹ may be substituted, a 3 or 4-valent, an aliphatic, cycloaliphatic, or aromatic hydrocarbon group.
p is 3 or 4. )

[0029]

Embedded image (In the formula, Z ² represents a trivalent or tetravalent aliphatic, alicyclic, or aromatic hydrocarbon group which may be substituted.
q is 3 or 4. )

Examples of the R ⁶ include, for example, any one of a branched alkylene group having 1 to 12 carbon atoms represented by the following formula (wherein R ⁷ is a hydrogen atom or a carbon atom Represents an alkyl group of Formulas 1 to 4).

[0031]

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As Z ¹ , for example, any of trivalent aromatic hydrocarbon groups represented by the following formula can be specifically mentioned.

[0033]

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As Z ² , for example, any of trivalent alicyclic or aromatic hydrocarbon groups represented by the following formula can be specifically mentioned.

[0035]

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[0036]

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Among the compounds having 3 to 4 oxetane rings in the molecule, in the chemical formula (9), R ⁵ is an alkyl group, and R ⁶ is a compound having 1 carbon atom represented by the above formula.
What is a group having a R ⁷ of the 12 branched alkylene group, or a is is preferable group represented by the formula (10). Further, in the above chemical formula (9), R ⁵ is an ethyl group, and R ⁶ is a branched alkylene group having 1 to 12 carbon atoms represented by the above formula, wherein R ⁷ is an ethyl group. Alternatively, it is preferable that in the chemical formula (10), p is 3 and Z ¹ is a group represented by the following formula.

[0038]

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[Acid Anhydride] In the thermosetting composition of the present invention, as the acid anhydride, a functional acid anhydride having an acid anhydride group represented by the chemical formula (12) (where k is 1 And R ⁸ represents an optionally substituted hydrocarbon group having a valency of 2, 4, or 6, corresponding to k = 1, 2, or 3, respectively. Hydrocarbon groups are those in which at least one of the carbon atoms in the main chain is replaced by another atom such as an oxygen atom, or at least one of the hydrogen atoms bonded to the carbon atom in the main chain or side chain , Or one or more of a carboxyl group and an acid anhydride group in the molecule. Preferred are free acid anhydrides. These acid anhydrides may be used alone or in combination.

[0040]

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As the functional acid anhydride, k = 1,
A monofunctional anhydride in which R ⁸ is a divalent hydrocarbon group, k =
2, a bifunctional acid anhydride in which R ⁸ is a tetravalent hydrocarbon group, and a trifunctional acid anhydride in which k = 3 and R ⁸ is a hexavalent hydrocarbon group.

Monofunctional acid anhydrides are acid anhydrides derived from dicarboxylic acids, and specifically include succinic anhydride, dodecyl succinic anhydride, maleic anhydride, glutaric anhydride, citraconic anhydride, itaconic anhydride. Acid, glutaconic anhydride, diglycolic anhydride, hexahydrophthalic anhydride, methylhexahydrophthalic anhydride, tetrahydrophthalic anhydride, methyltetrahydrophthalic anhydride, endocis-bicyclo [2,2,1] hept-5-ene-2 ,
3-dicarboxylic anhydride (trade name: nadic anhydride),
Methyl-endocis-bicyclo [2,2,1] hept-
5-ene-2,3-dicarboxylic anhydride (trade name: methylnadic anhydride), endmethylenetetrahydrophthalic anhydride, methylendomethylenetetrahydrophthalic anhydride, chlorendic anhydride, phthalic anhydride,
Examples thereof include nitrophthalic anhydride, diphenic anhydride, and naphthalic anhydride.

The bifunctional acid anhydride is an acid anhydride derived from tetracarboxylic acid, specifically, pyromellitic anhydride, 3,3 ′, 4,4′-benzophenonetetracarboxylic anhydride, Ethylene glycol bis (anhydrotrimate), 5- (2,5-dioxotetrahydro-
3-furanyl) -3-methyl-3-cyclohexene-
1,2-dicarboxylic anhydride and the like. The trifunctional acid anhydride is an acid anhydride derived from hexacarboxylic acid, and specific examples include hexahydromellitic anhydride and melitic anhydride.

The free acid anhydride includes β, γ
-Specific examples include aconitic anhydride, glycolic anhydride, trimellitic anhydride, polyazelain anhydride and the like.

Among the acid anhydrides, monofunctional acid anhydrides (maleic anhydride, phthalic anhydride, nadic anhydride, methylnadic anhydride, etc.) and bifunctional acid anhydrides (pyromellitic anhydride, etc.) are preferred. .

[Zinc carboxylate or acetylacetonate] In the thermosetting composition of the present invention, zinc carboxylate used as a catalyst includes zinc octylate, zinc laurate, zinc stearate, and palmitate. Zinc acid, zinc naphthenate, zinc pt-butyl benzoate, and the like. Examples of zinc acetylacetonate include:
Zinc acetylacetonate and the like can be mentioned. The zinc carboxylate and acetylacetonate may be used alone or in combination. Among them, zinc octylate, zinc laurate, zinc stearate, zinc palmitate, zinc naphthenate, zinc Acetylacetonate is preferred, and zinc octylate and zinc acetylacetonate are more preferred.

[Thermosetting Composition] The thermosetting composition of the present invention comprises the compound having an oxetane ring, an acid anhydride, and a carboxylate of zinc. In this composition, the acid anhydride is used in an amount of 0.4 to 2 times, particularly 0.7 to 1.5 times the stoichiometric amount represented by the following formula with respect to the compound having an oxetane ring. Is preferred.
The zinc carboxylate or acetylacetonate is preferably used in a proportion of 30% by weight or less, particularly 2 to 30% by weight, based on the compound having an oxetane ring.

When a compound having one oxetane ring in the molecule is used as the compound having an oxetane ring, the relationship represented by the formula (1) is satisfied, and 2 to 2 in the molecule.
When a compound having four oxetane rings is used,
Equation (2) holds.

N ₁ = (3 / 2k)-[(4k-3) / 2k] (1) (where k represents the number of acid anhydride groups contained in the acid anhydride, and the chemical formula (1) It has the same meaning as k in 12) .N ₁ represents the stoichiometric amount of the acid anhydride with respect to the compound having one oxetane ring in the molecule.)

N ₂ = (k ₀ / k) − [k ₀ (k−1) / k] = k ₀ (2−k) / k (2) (where k is the same as above and N ₂ Represents the stoichiometric amount of the acid anhydride with respect to the compound having 2 to 4 oxetane rings in the molecule, and k ₀ is contained in the compound having 2 to 4 oxetane rings in the molecule. Represents the number of oxetane rings, 2, 3, or 4.)

The thermosetting composition of the present invention may further contain a hydroxyl group-containing compound. In particular, when the compound having an oxetane ring does not contain a free hydroxyl group (not a compound having one oxetane ring in the molecule), it preferably contains a compound having a hydroxyl group. The content of the hydroxyl group-containing compound is such that the hydroxyl group is 0.05 to 5 with respect to the total amount of the compound having an oxetane ring and the acid anhydride.
% By weight, especially 0.1 to 3% by weight.
The hydroxyl group-containing compound may be used alone or in combination.

Examples of the hydroxyl group-containing compound include aliphatic monohydric alcohols having 3 to 20 carbon atoms such as propanol, butanol, hexanol, octanol and dodecanol; alicyclic monohydric alcohols such as cyclopentanol and cyclohexanol; Araliphatic monohydric alcohols such as benzyl alcohol, aromatic monohydric alcohols such as phenol, cresol, xylenol, and naphthol; and heterocyclic monohydric alcohols such as furfuryl alcohol;

Ethylene glycol, propylene glycol, 1,4-butanediol, 1,5-pentanediol, 1,6-hexanediol, 1,12-dodecanediol, diethylene glycol, triethylene glycol, dipropylene glycol, polyethylene glycol, Aliphatic dihydric alcohols such as polypropylene glycol, alicyclic dihydric alcohols such as 1,4-cyclohexanediol and 1,4-cyclohexanedimethanol,
Aromatic dihydric alcohols such as phthalyl alcohol and 1,4-dihydroxyethylbenzene, and aromatic dihydric alcohols such as resorcinol, catechol, hydroquinone and bisphenol A;

Examples include aliphatic polyhydric alcohols such as glycerin, trimethylolethane, trimethylolpropane, and pentaerythritol; aromatic polyhydric alcohols such as pyrogallol and phloroglucin; thioglycol; and water. Among the hydroxyl group-containing compounds, 1,5-pentanediol, 1,6-hexanediol, ethylene glycol, diethylene glycol, and phenol are preferred.

In the present invention, a compound that causes ring opening of an acid anhydride group and formation of a carboxyl group is used in place of the above-mentioned hydroxyl group-containing compound in the same ratio as the above-mentioned hydroxyl group-containing compound.
It can be used alone or in combination.

Such compounds include, for example, n-
Primary amines (monoamines) such as butylamine, n-hexylamine, n-octylamine, n-dodecylamine, cyclohexylamine, aniline, benzylamine, p-toluidine, di-n-propylamine, diisopropylamine, diisopropylamine -N-butylamine, piperidine,
Methyl aniline, ethyl aniline, dibenzylamine,
Secondary amines (monoamines) such as diphenylamine,

Diamines such as hydrazine, ethylenediamine, propylenediamine, tetramethylenediamine, hexamethylenediamine, 1,8-diaminooctane, 1,10-diaminododecane, piperazine, 4,4'-diaminodicyclohexylmethane and p-phenylenediamine And polyamines such as diethylenetriamine and triethylenetetramine; 1-aminoethanol, 2-aminoethanol, N-methylethanolamine, N-ethylethanolamine, N-methyldiethanolamine, N
Alkanolamines such as ethyldiethanolamine,

Methanesulfonic acid, benzenesulfonic acid,
p-Toluenesulfonic acid, naphthalene-α (or β)-
Sulfonic acid such as sulfonic acid, primary or secondary phosphine such as diisopropylphosphine, diisoamylphosphine, phenylphosphine, diphenylphosphine, glycolic acid, lactic acid, α-oxybutyric acid, glyceric acid, malic acid, tartaric acid, citric acid And oxyacids such as salicylic acid and p-oxybenzoic acid.

The thermosetting composition of the present invention can be cured by heating and thermosetting (reacting) the composition according to a conventional method. This thermosetting (reaction)
Is preferably carried out while maintaining a compound having an oxetane ring, an acid anhydride, a polycarboxylic acid generated from the acid anhydride, etc. in a dissolved state in a reaction solvent or in a molten state without a solvent. Therefore, the thermosetting temperature is preferably from 50 to 300 ° C. in the case of thermosetting in a molten state, and in the case of thermosetting in a molten state, either the melting point of a compound having an oxetane ring or the melting point of an acid anhydride. Preferably, the temperature is not lower than the lower melting point and not higher than 300 ° C.

In the heat curing, the pressure is not particularly limited, and may be any of reduced pressure, normal pressure, and pressurized pressure. The heat curing time varies depending on the type of the compound in the composition and the heat curing conditions, but may be 1 to 70 hours, preferably about 2 to 50 hours. Note that the thermal curing is preferably performed in an atmosphere of an inert gas such as nitrogen, argon, and helium.

The reaction solvent has an action of dissolving or swelling a compound having an oxetane ring, an acid anhydride, a polycarboxylic acid formed from the acid anhydride, and the like, and has no reactivity with these compounds. Is preferred. The amount of the reaction solvent used may be an amount capable of dissolving or swelling these compounds. For example, DMF, DMAC, HMP
When a polar solvent such as A, DMSO, NMP is used,
It may be about 1 to 10 times by volume with respect to 1 weight of the compound having an oxetane ring

Examples of such a reaction solvent include amide compounds such as N, N-dimethylformamide (DMF), N, N-dimethylacetamide (DMAC), hexamethylphosphoric triamide (HMPA), diethylene glycol dimethyl ether, Ether compounds such as diethylene glycol diethyl ether, triethylene glycol dimethyl ether, anisole, and phenetole; aromatic halogenated hydrocarbons such as o-dichlorobenzene and 3,4-dichlorotoluene; nitrobenzene; dimethyl sulfoxide (DMSO); Sulfolane, tetramethylurea, N-methyl-2-pyrrolidone (NMP) and the like. Among them, DMF, DMAC, HMP
A, DMSO, NMP are preferred.

After the thermosetting composition is thermally cured as described above, the reactant is cooled to room temperature by a conventional method such as air cooling or water cooling, and the resulting cured product is taken out of the reactor (if necessary). Then, by subsequently drying by a known method such as hot air drying, vacuum drying, or freeze drying at 100 ° C. or lower for 2 to 10 hours, a cured product having an insoluble and infusible three-dimensional structure can be obtained. When the thermosetting composition is heat-cured in a reaction solvent, a cured product may be obtained by evaporating the reaction solvent before cooling the reaction product, or a cured product obtained by cooling the reaction product May be a flexible cured product containing the reaction solvent.

Further, the thermosetting composition of the present invention comprises a metal,
After being applied to a base material such as rubber, plastic, molded parts, film, paper, wood, glass cloth, concrete, and ceramic, it can be cured by heating at a predetermined temperature for a predetermined time. That is, a substrate having the cured product as a film can be obtained.

As described above, the zinc carboxylate or acetylacetonate is used as a heat-curing accelerator (namely, zinc) for a thermosetting composition (particularly a thermosetting composition containing a compound having an oxetane ring). As a thermosetting accelerator containing a carboxylate or acetylacetonate.

When the thermosetting composition of the present invention is used, various known additives such as an inorganic filler, a reinforcing material, a coloring agent, and a stabilizer can be used as long as the effects of the present invention are not impaired. Agents (heat stabilizers, weather resistance improvers, etc.), extenders, viscosity modifiers, flame retardants, ultraviolet absorbers, antioxidants, discoloration inhibitors, antibacterial agents, antifungal agents, antioxidants, antistatic agents, Plasticizers, lubricants, foaming agents, mold release agents, etc. can be added and mixed.

[0067]

Next, the present invention will be described specifically with reference to examples and comparative examples. Example 1 As a compound having an oxetane ring, terephthalic acid (3-
100 parts by weight of ethyl-3-oxetanyl) methyl ester, 74 parts by weight of phthalic anhydride as an acid anhydride, 2 parts by weight of ethylene glycol as a hydroxyl group-containing compound with respect to a compound having an oxetane ring, as an organic acid salt of zinc A thermosetting composition containing 2 parts by weight of zinc octylate based on a compound having an oxetane ring was prepared at 130 ° C. for 5 hours.
Heated for a time to thermally cure. After a lapse of a predetermined time, the cured product obtained by cooling the reaction product to room temperature was observed and found to have a hardness equivalent to the pencil hardness HB.

Example 2 The same heat curing as in Example 1 was carried out except that the heating temperature was changed to 150 ° C. and the heating time was changed to 2 hours. The obtained cured product had a hardness corresponding to the pencil hardness HB.

Example 3 Thermal curing was carried out in the same manner as in Example 1 except that the zinc organic acid salt was replaced with zinc acetylacetonate (2 parts by weight based on the compound having an oxetane ring). The obtained cured product had a hardness corresponding to the pencil hardness HB.

Example 4 A thermosetting was performed in the same manner as in Example 3 except that the heating temperature was changed to 150 ° C. and the heating time was changed to 1 hour. The obtained cured product had a hardness corresponding to the pencil hardness HB.

[0071]

According to the present invention, a thermosetting composition containing a compound having an oxetane ring and an acid anhydride, which has an excellent thermosetting rate, can be provided. The thermosetting composition has excellent mechanical properties (tensile strength, hardness, etc.), electrical properties (insulating properties, etc.), adhesiveness, heat resistance, moisture resistance, chemical resistance, due to the curing reaction (intermolecular crosslinking). Showing sex, etc.
It forms a cured product of an insoluble and infusible three-dimensional structure,
Paints, coatings,
The use in adhesives, electrical insulating materials, sealing materials, laminates, concrete structure repair, reinforcing steel plate bonding, etc. can be greatly expected.

Claims (5)

[Claims] 1. A thermosetting composition comprising a compound having an oxetane ring, an acid anhydride, and a zinc carboxylate or acetylacetonate. 2. The thermosetting composition according to claim 1, further comprising a hydroxyl group-containing compound. 3. The thermosetting composition according to claim 1, wherein the compound having an oxetane ring is a compound having two oxetane rings in a molecule. 4. The thermosetting composition according to claim 1, wherein the acid anhydride is a monofunctional acid anhydride or a bifunctional acid anhydride. 5. A thermosetting accelerator containing a zinc carboxylate or acetylacetonate.