JP2013001803A - Blocking agent dissociation catalyst containing proazaphosphatrane and application of the catalyst - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a blocking agent dissociation catalyst containing proazaphosphatrane as a dissociation catalyst for a blocking agent, the catalyst showing a high dissociation effect at low temperature; and to provide a thermosetting composition comprising the above blocking agent dissociation catalyst, block isocyanate and a compound having an isocyanate reactive group.SOLUTION: The thermosetting composition contains a blocking agent dissociation catalyst, block isocyanate and a compound having an isocyanate reactive group, in which a catalyst containing proazaphosphatrane expressed by formula (1) is used as the blocking agent dissociation catalyst. In the formula, R, Rand Reach independently represent a hydrogen atom, a 1-15C aliphatic hydrocarbon group, a 6-9C aromatic hydrocarbon group or a trialkylsilyl group.

Description

  The present invention relates to a catalyst for dissociating a polyisocyanate blocking agent (hereinafter sometimes referred to as “blocking agent dissociation catalyst”), and a thermosetting composition using the same.

  Polyurethane resin coatings have very good wear resistance, chemical resistance and stain resistance. A general polyurethane resin coating is a two-component type composed of a polyol component and a polyisocyanate component, and each is stored separately and mixed for use during coating. However, since the paint once mixed is cured in a short time, there is a problem in terms of workability at the time of painting because the pot life is short. Further, since the polyisocyanate and water easily react, it is impossible to use in a water-based paint such as an electrodeposition paint. As described above, the conventional two-pack type polyurethane resin paint has many limitations in its use.

  In order to improve the above-mentioned problems, a method is known that uses a blocked isocyanate that is inactivated by reacting a polyisocyanate with an active hydrogen group-containing compound (blocking agent). This blocked isocyanate does not react with the polyol at room temperature, but when heated, the blocking agent dissociates to regenerate the isocyanate group, and the crosslinking reaction with the polyol proceeds. For this reason, the pot life is not limited, and it is possible to preliminarily blend both into a coating material to form a single solution or to apply to a water-based coating material.

  As compounds used as a polyisocyanate blocking agent, for example, ε-caprolactam, methyl ethyl ketone oxime, phenol and the like are known. However, blocked isocyanates using these require a high baking temperature of 140 ° C. or higher to dissociate the blocking agent, which is disadvantageous in terms of energy and cannot be applied to plastic substrates with low heat resistance. there were.

  For this reason, attempts have been conventionally made to lower the baking temperature by using a catalyst (blocking agent dissociation catalyst). As such a catalyst, organic tin such as dibutyltin dilaurate is known (for example, see Non-Patent Document 1), but its use is not preferred because of toxicity problems. In addition, a catalyst mixture of amino acid and bismuth (for example, see Patent Document 1), zinc borate (for example, see Patent Document 2) and the like have been reported as catalysts, but the dissociation temperature is not sufficiently lowered, and the temperature is low. There is a demand for a blocking agent dissociation catalyst having a high dissociation effect.

Japanese Patent No. 3293633 Japanese Patent No. 337536

Progress in Organic Coatings 36, 148-172 (1999)

  The present invention has been made in view of the above-described background art, and an object thereof is to provide a blocking agent dissociation catalyst having a high dissociation effect at a low temperature and its use.

  As a result of intensive studies to solve the above problems, the present inventors have found that proazaphosphatran is a dissociation catalyst for a blocking agent having a high dissociation effect at a low temperature, and has completed the present invention. It was.

  That is, this invention is a blocking agent dissociation catalyst containing proazaphosphatran as shown below, and a thermosetting composition using the same.

  [1] The following formula (1)

［式中、Ｒ^１、Ｒ^２、Ｒ^３は、各々独立して水素原子、炭素数１〜１５の脂肪族炭化水素基、炭素数６〜９の芳香族炭化水素基、又はトリアルキルシリル基を表す。］
で示されるプロアザホスファトランを含有するブロック剤解離触媒。

[Wherein R ¹ , R ² and R ³ are each independently a hydrogen atom, an aliphatic hydrocarbon group having 1 to 15 carbon atoms, an aromatic hydrocarbon group having 6 to 9 carbon atoms, or a trialkylsilyl group. Represents. ]
A blocking agent dissociation catalyst containing proazaphosphatran represented by

  [2] The following formula (1a)

で示されるトリイソブチルプロアザホスファトラン、及び下記式（１ｂ）

And triisobutylproazaphosphatran represented by the following formula (1b)

で示されるトリイソプロピルプロアザホスファトランからなる群より選択される少なくとも１種のプロアザホスファトランを含有するブロック剤解離触媒。

A blocking agent dissociation catalyst containing at least one proazaphosphatran selected from the group consisting of triisopropylproazaphosphatran represented by formula (1).

  [3] A thermosetting composition comprising the blocking agent dissociation catalyst according to the above [1] or [2], a blocked isocyanate and a compound having an isocyanate-reactive group.

  [4] The thermosetting composition as described in [3] above, wherein the compound having an isocyanate-reactive group is a polyol.

  Since the blocking agent dissociation catalyst containing proazaphosphatran of the present invention exhibits a blocking agent dissociation catalytic activity that exceeds that of known catalysts such as organic tin, it is extremely useful in industry.

  Moreover, since the thermosetting composition of the present invention uses a blocking agent dissociation catalyst having a high dissociation effect at a low temperature, it is advantageous in terms of energy and can be applied to a substrate having low heat resistance.

  Hereinafter, the present invention will be described in more detail.

  In the present invention, the blocking agent dissociation catalyst contains proazaphosphatran. In the present invention, proazaphosphatran is a compound represented by the above formula (1).

In the above formula (1), when any of R ^{1 to} R ⁴ is an aliphatic hydrocarbon group, the aliphatic hydrocarbon group may be linear or branched, and may be either saturated or unsaturated. Examples of the aliphatic hydrocarbon group having 1 to 15 carbon atoms include methyl group, ethyl group, n-propyl group, isopropyl group, n-butyl group, isobutyl group, sec-butyl group, tert-butyl group, n- Pentyl group, isopentyl group, neopentyl group, t-pentyl group, n-hexyl group, 1-methylpentyl group, 4-methyl-2-pentyl group, 3,3-dimethylbutyl group, 2-ethylbutyl group, n-heptyl Group, 1-methylhexyl group, n-octyl group, tert-octyl group, 1-methylheptyl group, 2-ethylhexyl group, 2-propylpentyl group, n-nonyl group, 2,2-dimethylheptyl group, 2, 6-dimethyl-4-heptyl group, 3,5,5-trimethylhexyl group, n-decyl group, n-undecyl group, 1-methyldecyl group, n-dodecyl group, - tridecyl group, 1-hexyl-heptyl group, n- tetradecyl, n- pentadecyl group, and the like.

In the above formula (1), when any of R ^{1 to} R ⁴ is an aromatic hydrocarbon group, the aromatic hydrocarbon group may have a substituent. Examples of the aromatic hydrocarbon group having 6 to 9 carbon atoms include a phenyl group, (o-, m-, p-) tolyl group, (2,3-, 2,4-, 2,5-, 2, Examples include 6-, 3,4-, 3,5-) xylyl group, (as-, v-, s-) pseudocumyl group, mesityl group, (o-, m-, p-) cumenyl group.

  Furthermore, in the above formula (1), examples of the trialkylsilyl group include those having an alkyl group having 1 to 4 carbon atoms. Specifically, a trimethylsilyl group, a triethylsilyl group, a tert-butyldimethylsilyl group, a triisopropylsilyl group and the like are exemplified as preferable ones.

  Although it does not specifically limit as a preparation method of proazaphosphatran, For example, by the method as described in US Pat. No. 5,051,533, US Pat. No. 5,260,436, US Pat. No. 5,698,737, etc. Can be prepared. Specifically, it can be prepared by reacting trialkyltris (2-aminoethyl) amine and chlorobis (dimethylamino) phosphine in a solvent and reacting the produced phosphatranyl chloride with an organic base. preferable.

  The trialkyltris (2-aminoethyl) amine used here is represented by the following formula (2):

［式中、Ｒ^１、Ｒ^２、Ｒ^３は、上記と同じ定義である。］
で示される化合物である。

[Wherein R ¹ , R ² and R ³ have the same definitions as above. ]
It is a compound shown by these.

  Specific examples of the trialkyltris (2-aminoethyl) amine include tris (2-aminoethyl) amine, trimethyltris (2-aminoethyl) amine, triethyltris (2-aminoethyl) amine, and tri-n- Propyltris (2-aminoethyl) amine, triisopropyltris (2-aminoethyl) amine, tri-n-butyltris (2-aminoethyl) amine, triisobutyltris (2-aminoethyl) amine, trisec-butyltris (2 -Aminoethyl) amine, tritert-butyltris (2-aminoethyl) amine, trimethylsilyltris (2-aminoethyl) amine, triphenyltris (2-aminoethyl) amine and the like.

  Examples of the solvent used here include dichloromethane, dichloroethane, toluene, benzene, diethyl ether and the like.

  Examples of the organic base used here include potassium tert-butoxide, sodium tert-butoxide, lithium tert-butoxide and the like.

  The blocking agent dissociation catalyst of the present invention contains proazaphosphatolane represented by the above formula (1), and among these, triisobutyl proazaphosphatran represented by the above formula (1a), Triisopropylproazaphosphatran represented by the above formula (1b), the following formula (1c)

で示されるトリメチルプロアザホスファトラン等を含有することが好ましい。

It is preferable to contain trimethylproazaphosphatran etc. shown by these.

  Next, the thermosetting composition of the present invention will be described.

  The thermosetting composition of the present invention contains the above-described blocking agent dissociation catalyst of the present invention, a blocked isocyanate, and a compound having an isocyanate-reactive group.

  In the thermosetting composition of the present invention, examples of the block isocyanate include non-aqueous blocked isocyanate and aqueous blocked isocyanate.

  Examples of the non-aqueous blocked isocyanate include known blocking agents (for example, alcohols such as methanol, ethanol, n-propanol, isopropanol, n-butanol, sec-butanol, tert-butanol, phenol, cresol, nitrophenol, chloro). Phenols such as phenol and resorcinol, thiols such as benzenethiol, caprolactams such as ε-caprolactam, carbamates such as ethyl carbamate, ketoenols such as acetylacetone, ketoximes such as methyl ethyl ketone oxime, diisopropylamine, triazole, 3, 5-methylpyrazole and other amines, sodium bisulfite, etc.) are used to list known isocyanate compounds or compounds that block their prepolymers. Rukoto can.

  Here, as a well-known isocyanate compound, aliphatic polyisocyanate, alicyclic polyisocyanate, aromatic polyisocyanate, araliphatic polyisocyanate etc. are mentioned, for example.

  Examples of the aliphatic polyisocyanate include 1,4-tetramethylene diisocyanate, 1,6-hexamethylene diisocyanate, 2,2,4-trimethylhexamethylene diisocyanate, 2,4,4-trimethylhexamethylene diisocyanate, lysine diisocyanate, And dimer acid diisocyanate.

  Examples of the alicyclic polyisocyanate include 1,3-bis (isocyanatomethyl) cyclohexane, 1,4-bis (isocyanatomethyl) cyclohexane, 3-isocyanatomethyl-3,3,5-trimethylcyclohexane (IPDI). , Isophorone diisocyanate), bis- (4-isocyanatocyclohexyl) methane (hydrogenated MDI), norbornane diisocyanate and the like.

  Examples of aromatic polyisocyanates include 2,4′-diphenylmethane diisocyanate, 4,4′-diphenylmethane diisocyanate, crude MDI, 1,4-phenylene diisocyanate, 2,4-tolylene diisocyanate, and 2,6-tolylene diisocyanate. 3,3′-dimethyl-4,4′-diisocyanatobiphenyl, 3,3′-dimethyl-4,4′-diisocyanatodiphenylmethane, 1,5-naphthylene diisocyanate and the like.

  Examples of the araliphatic polyisocyanate include 1,3-xylylene diisocyanate, 1,4-xylylene diisocyanate, α, α, α ′, α′-tetramethylxylylene diisocyanate, and the like.

  Moreover, as isocyanate compounds other than the above, for example, isocyanate group-terminated compounds by reaction of isocyanate compounds with active hydrogen group-containing compounds, reaction products of these compounds (for example, adduct-type polyisocyanates, allophanatization reactions, carbodiimidization reactions, Uretodione reaction, isocyanurate reaction, ureton iminate reaction, isocyanate-modified product by biuret reaction, etc.), or a mixture thereof.

  On the other hand, the aqueous blocked isocyanate can be obtained, for example, by reacting a polyisocyanate with a hydrophilic group having at least one active hydrogen group capable of reacting with an isocyanate group and blocking it with a known blocking agent. . Examples of the hydrophilic group include ionic groups such as cations and anions, and nonionic groups. Examples of the nonionic compound for introducing a nonionic group into the polyisocyanate include polyalkylene ether alcohols and polyoxyalkylene fatty acid esters.

  In the thermosetting composition of the present invention, examples of the compound having an isocyanate-reactive group include a polyol. In the present invention, the polyol refers to a compound containing two or more hydroxyl groups having reactivity with an isocyanate group, and specific examples include non-aqueous polyols and aqueous polyols.

  Examples of the non-aqueous polyol include acrylic polyol, polyester polyol, polyether polyol, and epoxy polyol.

  Examples of the acrylic polyol include a copolymer of a polymerizable monomer having one or more active hydrogens in one molecule and a monomer copolymerizable therewith.

  Examples of the polymerizable monomer having one or more active hydrogens in one molecule include acrylic acid hydroxy esters such as 2-hydroxyethyl acrylate, 2-hydroxypropyl acrylate, and 2-hydroxybutyl acrylate. , Methacrylic acid hydroxyesters such as methacrylic acid-2-hydroxyethyl, methacrylic acid-2-hydroxypropyl, methacrylic acid-2-hydroxybutyl, glycerin acrylic acid monoester or methacrylic acid monoester, trimethylolpropane acrylic acid Monoester or methacrylic acid monoester, or a monomer obtained by ring-opening polymerization of ε-caprolactone with these active hydrogens.

  Examples of monomers copolymerizable with the polymerizable monomer include, for example, acrylic esters such as methyl acrylate, ethyl acrylate, isopropyl acrylate, -n-butyl acrylate, and 2-ethylhexyl acrylate, and methyl methacrylate. , Methacrylates such as ethyl methacrylate, isopropyl methacrylate, n-butyl methacrylate, isobutyl methacrylate, n-hexyl methacrylate, cyclohexyl methacrylate, lauryl methacrylate, glycidyl methacrylate, acrylic acid, methacrylic acid , Unsaturated carboxylic acids such as maleic acid and itaconic acid, unsaturated amides such as acrylamide, N-methylol acrylamide and diacetone acrylamide, styrene, vinyl toluene, vinyl acetate, acrylonitrile, etc. It is.

  Examples of polyester polyols include condensed polyester polyols, polycarbonate polyols, and polylactone polyols.

  Examples of the condensed polyester polyol include ethylene glycol, propylene glycol, 1,3-propanediol, 1,4-butanediol, 1,5-pentanediol, 3-methyl-1,5-pentanediol, 1,6- Dioxanes such as hexanediol, neopentyl glycol, butylethylpropane diol, diethylene glycol, triethylene glycol, tetraethylene glycol, polyethylene glycol, dipropylene glycol, tripropylene glycol, and succinic acid, adipic acid, azelaic acid, sebacic acid, Dodecanedicarboxylic acid, maleic anhydride, fumaric acid, 1,3-cyclopentanedicarboxylic acid, 1,4-cyclohexanedicarboxylic acid, terephthalic acid, isophthalic acid, phthalic acid, naphthalenedicarbo Reaction products of dicarboxylic acids such as acid.

  Specifically, polyethylene adipate diol, polybutylene adipate diol, polyhexamethylene adipate diol, polyneopentylene adipate diol, polyethylene propylene adipate diol, polyethylene butylene adipate diol, polybutylene hexamethylene adipate diol, poly (polytetramethylene ether) ) Adipate-type condensed polyester diols such as adipate diol, and azelate-type condensed polyester diols such as polyethylene azelate diol and polybutylene azelate diol.

  Examples of the polycarbonate polyol include ethylene glycol, propylene glycol, 1,3-propanediol, 1,4-butanediol, 1,5-pentanediol, 3-methyl-1,5-pentanediol, and 1,6-hexane. Examples include diols, neopentyl glycol, butyl ethyl propane diol, diethylene glycol, triethylene glycol, tetraethylene glycol, polyethylene glycol, dipropylene glycol, tripropylene glycol and other diols and dimethyl carbonate and other dialkyl carbonates. It is done. Specifically, polytetramethylene carbonate diol, poly 3-methylpentamethylene carbonate diol, polyhexamethylene carbonate diol and the like are exemplified.

  Examples of polylactone polyols include ring-opening polymers of ε-caprolactone, γ-butyrolactone, γ-valerolactone, and mixtures of two or more thereof. Specific examples include polycaprolactone diol.

  Examples of the polyether polyol include ethylene glycol, propylene glycol, 1,3-butylene glycol, 1,4-butanediol, 1,6-hexanediol, diethylene glycol, neopentyl glycol, catechol, hydroquinone, bisphenol A, and the like. Examples include a reaction product obtained by addition polymerization of monomers such as ethylene oxide, propylene oxide, butylene oxide, styrene oxide, epichlorohydrin, tetrahydrofuran, and cyclohexylene, using a compound containing two or more hydrogen atoms as an initiator. In the case of a reaction product obtained by addition polymerization of two or more monomers, block addition, random addition, or a mixed system of both may be used. Specific examples include polyethylene glycol, polypropylene glycol, polytetramethylene ether glycol and the like.

  Examples of the epoxy polyol include novolak type, β-methyl epichloro type, cyclic oxirane type, glycidyl ether type, glycol ether type, aliphatic unsaturated compound epoxy type, epoxidized fatty acid ester type, polyvalent carboxylic acid ester type, amino acid Examples include glycidyl type, halogenated type, and resorcin type epoxy polyols.

  Moreover, as non-aqueous polyols other than those described above, for example, OH-terminated prepolymers produced by reacting these polyols with isocyanate compounds can also be used.

  On the other hand, examples of the aqueous polyol include compounds obtained by emulsifying, dispersing, or dissolving the above-described non-aqueous polyol in water. Examples of the method of emulsifying, dispersing or dissolving in water include a method of neutralizing by introducing a carboxyl group, a sulfone group or the like. Examples of neutralizers include ammonia and water-soluble amino compounds such as monoethanolamine, ethylamine, dimethylamine, diethylamine, triethylamine, propylamine, dipropylamine, isopropylamine, diisopropylamine, triethanolamine, and butylamine. , Dibutylamine, 2-ethylhexylamine, methylethanolamine, dimethylethanolamine, diethylethanolamine, morpholine and the like. Among these, tertiary amines such as triethylamine and dimethylethanolamine are preferably used.

  In the thermosetting composition of the present invention, the hydroxyl value of the polyol is not particularly limited, but is preferably in the range of 10 to 300 mgKOH / g, more preferably in the range of 20 to 250 mgKOH / g per solid content. . By setting the hydroxyl value to 10 mgKOH / g or more, the strength of the obtained resin is improved, and by setting it to 300 mgKOH / g or less, the plasticity of the obtained resin is improved.

  In the thermosetting composition of the present invention, the polyol component is a composition containing a polyol (a compound containing two or more hydroxyl groups having reactivity with an isocyanate group), a neutralizing agent, an antioxidant, and water. Usually used, the solid content means a polyol, a neutralizing agent, and an antioxidant.

  The hydroxyl value of the polyol can be measured by the method defined in JIS-K0070. That is, it can be measured by adding and dissolving acetic anhydride and pyridine to a sample, allowing to cool, and then neutralizing titrating a sample solution prepared by adding water and toluene with an ethanol solution of potassium hydroxide. The hydroxyl value is represented by the number of mg of potassium hydroxide required to neutralize acetic acid consumed to acetylate the hydroxyl group contained in a 1 g sample.

  The equivalent ratio ([hydroxyl group] / [isocyanate group]) of the hydroxyl group and isocyanate group of the polyol in the thermosetting composition of the present invention is determined by the required coating film properties and is not particularly limited. It is in the range of 0.2-2.

  The amount of the blocking agent dissociation catalyst of the present invention used in the thermosetting composition of the present invention is the amount of the above-mentioned proazaphosphatran used relative to the amount of blocked isocyanate ([the amount of proazaphosphatran used] / [ The use amount of the blocked isocyanate]) is usually 0.1 to 15% by weight, preferably 0.5 to 10% by weight, more preferably 1 to 5% by weight. Sufficient low-temperature curability can be obtained by setting the amount of proazaphosphatran used to be 0.1% by weight or more based on the amount of blocked isocyanate used. On the other hand, even if the amount of proazaphosphatran used exceeds 15% by weight based on the amount of blocked isocyanate, no further improvement in low-temperature curability is observed, which is economically disadvantageous.

  The amount of the blocking agent dissociation catalyst of the present invention used in the thermosetting composition of the present invention is the amount of the above-mentioned proazaphosphatran used relative to the solid content ([the amount of proazaphosphatran used] / [solid Min]) is usually in the range of 0.05 to 10% by weight, preferably 0.25 to 5% by weight, more preferably 0.5 to 3% by weight. In the present invention, the “solid content” represents a component other than the solvent in the thermosetting composition. For example, in the case of a non-aqueous thermosetting composition, other than the solvent such as butyl acetate and methyl ethyl ketone in the non-aqueous polyol. And the components other than the solvent such as methyl ethyl ketone in the non-aqueous blocked isocyanate, and in the case of the aqueous thermosetting composition, the components other than the solvent such as water in the aqueous polyol and the aqueous blocked isocyanate The total with components other than solvents, such as water, is represented. Sufficient low-temperature curability can be obtained by setting the use amount of proazaphosphatran to 0.05% by weight or more based on the solid content. On the other hand, even if the amount of proazaphosphatran used exceeds 10% by weight based on the solid content, no further improvement in low-temperature curability is observed, which is economically disadvantageous.

  In the thermosetting composition of the present invention, additives, pigments, solvents and the like commonly used in the technical field can be used as necessary.

  Additives are not particularly limited, for example, hindered amine-based, benzotriazole-based, benzophenone-based ultraviolet absorbers, perchlorate-based, hydroxylamine-based coloring inhibitors, hindered phenol-based, Examples thereof include phosphorus-based, sulfur-based and hydrazide-based antioxidants, tin-based, zinc-based and amine-based urethanization catalysts, leveling agents, rheology control agents, pigment dispersants and the like.

  Examples of the pigment include, but are not limited to, organic pigments such as quinacridone, azo, and phthalocyanine, inorganic pigments such as titanium oxide, barium sulfate, calcium carbonate, and silica, other carbon pigments, and metal foils. And pigments such as pigments and rust preventive pigments.

  Examples of the solvent include, but are not limited to, hydrocarbons such as benzene, toluene, xylene, cyclohexane, mineral spirit, naphtha, ketones such as acetone, methyl ethyl ketone, and methyl isobutyl ketone, ethyl acetate, and acetic acid-n. -Esters, such as butyl and cellosolve acetate, are mentioned, These solvents may be used independently and may use 2 or more types together.

  The thermosetting composition of the present invention is a precoat metal / rust preventive for metal products such as top and middle coatings for automobiles, chipping-resistant coatings, electrodeposition coatings, automotive parts coatings, automotive repair coatings, home appliances and office equipment. It can be used as a steel sheet, a paint for building materials, a paint for plastics, an adhesive, an adhesiveness imparting agent, a sealing agent and the like.

  The following examples further illustrate the present invention, but the present invention is not limited to these examples.

  In the following examples, baking of the thermosetting composition and measurement of solvent resistance were carried out as shown below.

<Baking of thermosetting composition>
The thermosetting composition was applied to an aluminum plate (A1050 made by Partec Co., Ltd.), preliminarily dried in an oven at 50 ° C. for 30 minutes, and then baked in an oven at a predetermined temperature for 30 minutes.

<Measurement of solvent resistance>
The above-mentioned baked coating film was cooled to room temperature, then rubbed with absorbent cotton soaked with methyl ethyl ketone, and the number of round trips until the coating film surface was scratched was measured to evaluate the solvent resistance.

Production Example 1
(Preparation of non-aqueous blocked isocyanate)
A stirring blade was attached to a four-necked flask equipped with a nitrogen blowing tube, and the inside of the vessel was made into a nitrogen atmosphere. Then, Coronate HX (manufactured by Nippon Polyurethane Co., Ltd., hexamethylene diisocyanate trimer, NCO 21.3 wt% ) 50.2 g and dehydrated methyl ethyl ketone 114 g were charged and stirred at 40 ° C. for 5 minutes. Thereafter, a dropping funnel was attached to the container, and 22.2 g of methyl ethyl ketone oxime was dropped into the container over 1 hour while maintaining the temperature at 40 ° C. Then, a reflux condenser was attached to the container and reacted at 70 ° C. for 1 hour. When isocyanate was no longer detected, the reaction was stopped by cooling to room temperature to obtain a non-aqueous blocked isocyanate. The obtained non-aqueous blocked isocyanate had a solid concentration of 40.0% by weight and an effective NCO of 1.36 mmol / g.

  Here, the effective NCO means the amount of isocyanate groups (NCO) that can be reacted by heating the blocked isocyanate to dissociate the blocking agent. An effective NCO of 1.36 mmol / g means that 1.36 mmol of isocyanate groups are potentially contained in 1 g of blocked isocyanate (regenerated by dissociation of the blocking agent).

Production Example 2
(Preparation of aqueous blocked isocyanate)
A stirring blade and a reflux condenser were attached to a four-necked flask equipped with a nitrogen blowing tube, and the inside of the vessel was made a nitrogen atmosphere. Then, 41.7 g of Coronate HX (manufactured by Nippon Polyurethane, Hexamethylene diisocyanate trimer, NCO 21.3% by weight) and 37.5 g of polyethylene glycol monomethyl ether (Aldrich, average molecular weight 550) were charged in the container, The reaction was carried out at 110 ° C. for 7 hours. Thereafter, 11.9 g of methyl ethyl ketone oxime and 22.0 g of methyl ethyl ketone were added to the container and reacted at 80 ° C. for 2 hours. When no isocyanate was detected, the reaction was stopped by cooling to room temperature.

  137 g of water was gradually added to 113 g of the obtained composition while stirring, and emulsified and dispersed in water. Residual methyl ethyl ketone was removed from the obtained emulsified dispersion with an evaporator. The obtained aqueous blocked isocyanate was a stable dispersion having a solid concentration of 40.0% by weight and an effective NCO of 0.905 mmol / g.

Production Example 3
(Preparation of proazaphosphatran-containing aqueous blocked isocyanate)
A stirring blade and a reflux condenser were attached to a four-necked flask equipped with a nitrogen blowing tube, and the inside of the vessel was made a nitrogen atmosphere. Subsequently, 20.9 g of Coronate HX (manufactured by Nippon Polyurethane Co., Ltd., hexamethylene diisocyanate trimer, NCO 21.3% by weight) and 18.8 g of polyethylene glycol monomethyl ether (manufactured by Aldrich, average molecular weight 550) were placed in the container, The reaction was carried out at 110 ° C. for 7 hours. Thereafter, 5.95 g of methyl ethyl ketone oxime and 11.0 g of methyl ethyl ketone were added to the container and reacted at 80 ° C. for 2 hours. When no isocyanate was detected, the reaction was stopped by cooling to room temperature.

  1.45 g of triisobutylproazaphosphatran (manufactured by Aldrich) represented by the above formula (1a) was gradually added to 56.6 g of the obtained composition while stirring, and then 67.9 g of water was stirred. The mixture was gradually added and emulsified and dispersed in water. Residual methyl ethyl ketone was removed from the obtained emulsified dispersion with an evaporator. The obtained proazaphosphatran-containing aqueous blocked isocyanate was a stable dispersion having a solid content concentration of 40.0% by weight and an effective NCO of 0.905 mmol / g.

Example 1.
(Evaluation of catalytic activity of proazaphosphatran in non-aqueous thermosetting composition)
Non-aqueous acrylic polyol (produced by DIC, Acrydic A-801, solid content concentration 50.2 wt%, hydroxyl value 102 mg KOH / g based on solid content) with composition shown in Table 1, non-aqueous obtained in Production Example 1 After mixing the blocked isocyanate, an 8% by weight propylene glycol monomethyl ether acetate solution of triisobutyl proazaphosphatran (manufactured by Aldrich) represented by the above formula (1a) was added with stirring, and triisobutyl proazaphosphater was added. A non-aqueous thermosetting composition containing Trang was obtained.

  The obtained non-aqueous thermosetting composition was baked at 90 ° C., 100 ° C., 110 ° C., 120 ° C., and 130 ° C., and the results of measuring the solvent resistance are shown in Table 1.

実施例２．
表１に示す組成で、非水性アクリルポリオール（ＤＩＣ社製、アクリディックＡ−８０１、固形分濃度５０．２重量％、固形分に対する水酸基価１０２ｍｇＫＯＨ／ｇ）、製造例１で得られた非水性ブロックイソシアネートを混合した後、上記式（１ｂ）で示されるトリイソプロピルプロアザホスファトラン（アルドリッチ社製）の８重量％プロピレングリコールモノメチルエーテルアセテート溶液を攪拌しながら添加し、トリイソプロピルプロアザホスファトランを含有する非水性熱硬化性組成物を得た。

Example 2
Non-aqueous acrylic polyol (produced by DIC, Acrydic A-801, solid content concentration 50.2 wt%, hydroxyl value 102 mg KOH / g based on solid content) with composition shown in Table 1, non-aqueous obtained in Production Example 1 After mixing the blocked isocyanate, an 8 wt% propylene glycol monomethyl ether acetate solution of triisopropylproazaphosphatran (Aldrich) represented by the above formula (1b) was added with stirring, and triisopropylproazaphosphater was added. A non-aqueous thermosetting composition containing Trang was obtained.

  The obtained non-aqueous thermosetting composition was baked at 90 ° C., 100 ° C., 110 ° C., 120 ° C., and 130 ° C., and the results of measuring the solvent resistance are shown in Table 1.

Comparative Example 1
(Curability evaluation without addition of catalyst in non-aqueous thermosetting composition)
Non-aqueous acrylic polyol (made by DIC, ACRICID A-801, solid content concentration of 50.2 wt%, hydroxyl value of 102 mg KOH / g based on solid content) with composition shown in Table 2, non-aqueous obtained in Production Example 1 Block isocyanate was mixed to obtain a non-aqueous thermosetting composition containing no catalyst.

  The obtained non-aqueous thermosetting composition was baked at 90 ° C., 100 ° C., 110 ° C., 120 ° C., and 130 ° C., and the results of solvent resistance measurement are also shown in Table 1.

  As is clear from Table 1, in Comparative Example 1, the number of rubbing was less than 5 at 130 ° C. and the coating film was not cured, whereas in Examples 1 and 2, the number of rubbing reached 100 times at 100 ° C. Since the film is cured, it can be seen that the dissociation temperature of the blocking agent was lowered by the addition of proazaphosphatran.

Comparative Example 2
(Curability evaluation of known catalysts in non-aqueous thermosetting compositions)
Non-aqueous acrylic polyol (made by DIC, ACRICID A-801, solid content concentration of 50.2 wt%, hydroxyl value of 102 mg KOH / g based on solid content) with composition shown in Table 2, non-aqueous obtained in Production Example 1 After mixing the blocked isocyanate, an 8 wt% propylene glycol monomethyl ether acetate solution of dibutyltin dilaurate was added with stirring to obtain a non-aqueous thermosetting composition containing a known catalyst.

  The obtained non-aqueous thermosetting composition was baked at 90 ° C., 100 ° C., 110 ° C., 120 ° C., and 130 ° C., and the results of solvent resistance measurement are shown in Table 2.

表１、２から明らかなとおり、比較例２では１３０℃においてラビング回数が１００回に達するのに対し、実施例１〜３では１００℃においてラビング回数が１００回に達することから、プロアザホスファトランはジブチル錫ジラウレートより優れたブロック剤低温解離活性を持つことがわかる。

As is clear from Tables 1 and 2, in Comparative Example 2, the number of rubbing reached 100 times at 130 ° C., whereas in Examples 1 to 3, the number of rubbing reached 100 times at 100 ° C. It can be seen that tolan has a blocking agent low-temperature dissociation activity superior to that of dibutyltin dilaurate.

Comparative Example 3 to Comparative Example 6
With the composition shown in Table 2, a non-aqueous thermosetting composition containing a known catalyst was obtained in the same manner as in Comparative Example 2.

  The obtained non-aqueous thermosetting composition was baked at 90 ° C., 100 ° C., 110 ° C., 120 ° C., and 130 ° C., and the results of solvent resistance measurement are also shown in Table 2.

  As is clear from Tables 1 and 2, the number of rubbing reaches 100 times at 120 ° C. in Comparative Example 3 and 130 ° C. in Comparative Example 4, and the number of rubbing times at 130 ° C. in Comparative Examples 4 and 5 is less than 5 times. In contrast, in Examples 1 and 2, the number of rubbing reaches 100 times at 100 ° C., so proazaphosphatran is zinc 2-ethylhexanoate, triphenylbismuth, 1,8-diazabicyclo [5.4.0]. It can be seen that the blocking agent has a low-temperature dissociation activity superior to that of -7-undecene (DBU) and 1,5-diazabicyclo [4.3.0] -5-nonene (DBN).

Example 4
(Evaluation of catalytic activity of proazaphosphatran in aqueous thermosetting composition)
Proaza obtained in Production Example 3 with a composition shown in Table 3 and an aqueous acrylic polyol (manufactured by Asia, WAP-768, solid content concentration 40.0% by weight, hydroxyl value with respect to solid content 57.5 mgKOH / g) Aqueous thermosetting composition containing proazaphosphatolan was obtained by mixing phosphatolan-containing aqueous blocked isocyanate.

  Table 3 shows the results of measuring the solvent resistance after baking the obtained aqueous thermosetting composition at 120 ° C, 130 ° C, 140 ° C and 150 ° C.

比較例７．
（水性熱硬化性組成物における触媒無添加の硬化性評価）
表３に示す組成で、水性アクリルポリオール（亜細亜工業社製、ＷＡＰ−７６８、固形分濃度４０．０重量％、固形分に対する水酸基価５７．５ｍｇＫＯＨ／ｇ）、製造例２で得られた水性ブロックイソシアネートを混合し、触媒を含有しない水性熱硬化性組成物を得た。

Comparative Example 7
(Curability evaluation without addition of catalyst in aqueous thermosetting composition)
An aqueous acrylic polyol (manufactured by Asia, WAP-768, solid content concentration 40.0% by weight, hydroxyl value 57.5 mgKOH / g based on solid content) having the composition shown in Table 3 and the aqueous block obtained in Production Example 2. Isocyanate was mixed to obtain an aqueous thermosetting composition containing no catalyst.

  Table 3 shows the results of measuring the solvent resistance after baking the obtained aqueous thermosetting composition at 120 ° C, 130 ° C, 140 ° C and 150 ° C.

  As is clear from Table 3, the number of rubbing reaches 100 times at 150 ° C. in Comparative Example 7, whereas the number of rubbing reaches 100 times at 130 ° C. in Example 4, so that by adding proazaphosphatran It can be seen that the dissociation temperature of the blocking agent has decreased.

Claims (4)

Following formula (1)

[Wherein R ¹ , R ² and R ³ are each independently a hydrogen atom, an aliphatic hydrocarbon group having 1 to 15 carbon atoms, an aromatic hydrocarbon group having 6 to 9 carbon atoms, or a trialkylsilyl group. Represents. ]
A blocking agent dissociation catalyst containing proazaphosphatran represented by The following formula (1a)

And triisobutylproazaphosphatran represented by the following formula (1b)

A blocking agent dissociation catalyst containing at least one proazaphosphatran selected from the group consisting of triisopropylproazaphosphatran represented by formula (1). A thermosetting composition comprising the blocking agent dissociation catalyst according to claim 1 or 2, a blocked isocyanate, and a compound having an isocyanate-reactive group. The thermosetting composition according to claim 3, wherein the compound having an isocyanate-reactive group is a polyol.