JP2019094384A - Curable composition - Google Patents

Abstract

To provide a curable composition containing an isocyanate group-containing urethane prepolymer, the curable composition having excellent foaming resistance and softening resistance at the time of heat curing.SOLUTION: A curable composition contains an isocyanate group-containing urethane prepolymer and an ester compound represented by the following formula (1) (where n is an integer of 1-3, R is an aliphatic hydrocarbon group. Each aliphatic hydrocarbon group may be linear or branched one. If n is 2 or 3, the total number of carbon atoms of each aliphatic hydrocarbon group is 20-60, and each aliphatic hydrocarbon group may be the same or different).SELECTED DRAWING: None

Description

  The present invention relates to a curable composition excellent in foaming resistance and softening resistance at the time of heat curing.

  In production lines for vending machines, vehicles, etc., press-formed steel plates are assembled by partial welding such as spot welding to form a structure, and joints, gaps or edges of the structure are covered with a covering material to form an airtightness. , Water tightness, rust prevention etc. As the coating material, a thermosetting type coating material which is cured in a short time from the viewpoint of the working efficiency of the production line and the like is used. The thermosetting type coating material is required to have good workability at the time of application, to be excellent in rust prevention, to be favorably filled in the gap portion of the steel plate joint, and to form a relatively thick coating film. In addition, it is required to be easily cured by heating, to be excellent in adhesion to a steel plate, and to be excellent in adhesion to a coating material to be performed after application of a covering material. As a thermosetting type covering material, a plastic sol of polyvinyl chloride, a thermosetting type resin composition, etc. have been proposed, and the present applicant has also proposed a one-component type thermosetting composition (Patent Document 1) reference). Although the one-component thermosetting composition of Patent Document 1 is excellent in storage stability, thermosetting property, adhesiveness and the like, if the heat curing temperature at the time of thermosetting is increased to shorten the time of the production process, the thermosetting is achieved. It turned out that it sometimes foamed and softened.

JP, 2010-189541, A

  An object of the present invention is to provide a curable composition excellent in foaming resistance and softening resistance at the time of heat curing.

（式中、ｎは１〜３の整数であり、Ｒは脂肪族炭化水素基である。該脂肪族炭化水素基は、直鎖であってもよく、分岐であってもよい。該脂肪族炭化水素の炭素数の総数は２０〜６０であり、ｎが２または３の場合、該脂肪族炭化水素基はそれぞれ同一であっても異なっていてもよい。）
〔２〕前記式（１）で示すエステル化合物の配合量が前記硬化性組成物全体の３〜４０質量％であることを特徴とする〔１〕に記載の硬化性組成物。
〔３〕さらに、ポリ塩化ビニルを含有することを特徴とする〔１〕または〔２〕に記載の硬化性組成物。
〔４〕さらに、オキサゾリジン化合物を含有することを特徴とする〔１〕〜〔３〕のいずれかに記載の硬化性組成物。
〔５〕さらに、硬化促進触媒、可塑剤、安定剤、充填剤、揺変性付与剤、接着性向上剤、貯蔵安定性向上剤、着色剤および有機溶剤から選択される１種以上の添加剤を含有することを特徴とする〔１〕〜〔４〕のいずれかに記載の硬化性組成物。
〔６〕熱硬化性組成物であることを特徴とする〔１〕〜〔５〕のいずれかに記載の硬化性組成物。 As a result of intensive studies to solve the above-mentioned problems, the present inventors have found that a curable composition containing an isocyanate group-containing urethane prepolymer and a specific ester compound is excellent in foaming resistance and softening resistance at the time of heat curing. The present invention has been completed. That is, the present invention is as shown in [1] to [6].
[1] A curable composition comprising an isocyanate group-containing urethane prepolymer and an ester compound represented by the formula (1).

(Wherein n is an integer of 1 to 3 and R is an aliphatic hydrocarbon group. The aliphatic hydrocarbon group may be linear or branched, and may be branched. Aliphatic The total number of carbon atoms of hydrocarbons is 20 to 60, and when n is 2 or 3, the aliphatic hydrocarbon groups may be the same or different.)
[2] The curable composition according to [1], wherein the compounding amount of the ester compound represented by the formula (1) is 3 to 40% by mass of the whole of the curable composition.
[3] The curable composition as described in [1] or [2], further comprising polyvinyl chloride.
[4] The curable composition according to any one of [1] to [3], further comprising an oxazolidine compound.
[5] Further, one or more additives selected from a curing accelerating catalyst, a plasticizer, a stabilizer, a filler, a thixotropic agent, an adhesion improver, a storage stability improver, a colorant and an organic solvent The curable composition as described in any one of [1]-[4] characterized by containing.
[6] The curable composition according to any one of [1] to [5], which is a thermosetting composition.

  The curable composition of the present invention is excellent in foaming resistance and softening resistance at the time of heat curing.

  Hereinafter, the present invention will be described in detail based on embodiments.

式中、ｎは１〜３の整数であり、Ｒは脂肪族炭化水素基である。該脂肪族炭化水素基は、直鎖であってもよく、分岐であってもよい。該脂肪族炭化水素基の炭素数の総数は２０〜６０であり、ｎが２または３の場合、該脂肪族炭化水素基はそれぞれ同一であっても異なっていてもよい。 The curable composition of the present invention is characterized by containing an isocyanate group-containing urethane prepolymer and an ester compound represented by the formula (1). Each component will be described in detail below.

In the formula, n is an integer of 1 to 3 and R is an aliphatic hydrocarbon group. The aliphatic hydrocarbon group may be linear or branched. The total number of carbon atoms of the aliphatic hydrocarbon group is 20 to 60, and when n is 2 or 3, the aliphatic hydrocarbon groups may be the same or different.

  The isocyanate group-containing urethane prepolymer (hereinafter sometimes simply referred to as "urethane prepolymer") will be described. The isocyanate group-containing urethane prepolymer is a compound having one or more isocyanate groups in the resin. The isocyanate group reacts with an active hydrogen-containing compound (for example, water such as moisture) to form a urea bond or a urethane bond to crosslink and cure, and at the same time the composition after curing has good adhesion with the adherend surface It is given.

  The isocyanate group-containing urethane prepolymer is obtained by combining the organic isocyanate compound and the active hydrogen-containing compound at a molar ratio of isocyanate group / active hydrogen (group) of 1.2 to 10, preferably 1.2 to 5, or It is made to react sequentially and it synthesize | combines so that an isocyanate group may remain in a urethane prepolymer.

  The number average molecular weight of the isocyanate group-containing urethane prepolymer is 1,000 or more, preferably 1,000 to 20,000, more preferably 2,000 to 15,000, and particularly preferably 2,000 to 10,000. . In addition, the number average molecular weight in this invention is a numerical value of polystyrene conversion measured by gel permeation chromatography (GPC).

  The isocyanate group-containing urethane prepolymer can be produced by a conventionally known method. Specifically, an organic isocyanate compound and an active hydrogen-containing compound are charged into a reaction vessel made of glass or stainless steel, and a reaction catalyst and an organic solvent are added as needed, and the reaction is carried out while stirring at 50 to 120 ° C. It can be mentioned. At this time, since the urethane prepolymer thickens when the isocyanate group of the organic isocyanate compound reacts with water such as moisture, it is preferable to replace the inside of the container with nitrogen gas in advance or to perform the reaction under nitrogen gas flow.

  As an organic isocyanate compound, organic polyisocyanate can be mentioned. The organic polyisocyanate is a compound having two or more isocyanate groups in the compound. Specifically, toluene polyisocyanates such as 2,4-toluene diisocyanate and 2,6-toluene diisocyanate, diphenylmethanes such as 4,4'-diphenylmethane diisocyanate, 2,4'-diphenylmethane diisocyanate and 2,2'-diphenylmethane diisocyanate Polyisocyanate, 1,2-phenylene diisocyanate, 1,3-phenylene diisocyanate, 1,4-phenylene diisocyanate, 2,4,6-trimethylphenyl-1,3-diisocyanate, 2,4,6-triisopropylphenyl-1 Phenylene polyisocyanates such as 1,3-diisocyanate, naphthalene polyisocyanates such as 1,4-naphthalene diisocyanate, 1,5-naphthalene diisocyanate, and other aromatic polymers As cyanate, chlorophenylene-2,4-diisocyanate, 4,4'-diphenylether diisocyanate, 3,3'-dimethyldiphenylmethane-4,4'-diisocyanate, 3,3'-dimethoxydiphenyl-4,4'-diisocyanate It can be mentioned. Further, 1,6-hexamethylene diisocyanate, 1,5-pentamethylene diisocyanate, 1,4-tetramethylene diisocyanate, 2,2,4-trimethyl-1,6-hexamethylene diisocyanate, 2,4,4-trimethyl- Aliphatic polyisocyanates such as 1,6-hexamethylene diisocyanate, decamethylene diisocyanate and lysine diisocyanate, aromatic aliphatic polyisocyanates such as o-xylylene diisocyanate, m-xylylene diisocyanate and p-xylylene diisocyanate, 1,4- Alicyclic polyisocyanates such as cyclohexyl diisocyanate, isophorone diisocyanate, hydrogenated toluene diisocyanate, hydrogenated xylylene diisocyanate, hydrogenated diphenylmethane diisocyanate, etc. Door and the like. In addition, polymeric isocyanates such as polymethylene polyphenyl polyisocyanate and crude toluene diisocyanate can be mentioned. Furthermore, modified isocyanates having one or more of uretdione bond, isocyanurate bond, allophanate bond, buret bond, uretonimine bond, carbodiimide bond, urethane bond or urea bond obtained by modifying these organic polyisocyanates can be mentioned. Any of these may be used alone or in combination of two or more.

  In addition to organic polyisocyanate, organic monoisocyanate can be used. That is, a mixture of organic polyisocyanate and organic monoisocyanate can be used as the organic isocyanate compound. The organic monoisocyanate is a compound having one isocyanate group in the compound, and specifically, n-butyl monoisocyanate, n-hexyl monoisocyanate, n-hexadecyl monoisocyanate, n-octadecyl monoisocyanate, p -Isopropylphenyl monoisocyanate, p-benzyloxyphenyl monoisocyanate can be mentioned.

  An active hydrogen-containing compound is a compound having one or more active hydrogens (groups) in the compound. Specifically, other than high molecular weight polyol and high molecular weight polyamine, low molecular weight polyol optionally used as chain extender, low molecular weight amino alcohol, low molecular weight polyamine, and high molecular weight or low molecular weight used for modification of urethane prepolymer Monol is mentioned. In the present invention, a polymer compound as an active hydrogen-containing compound means a compound having a number average molecular weight of 500 or more, and a low molecular weight compound means a compound having a number average molecular weight of less than 500.

  Examples of the high molecular weight polyol include polyester polyol, polycarbonate polyol, polyoxyalkylene type polyol, hydrocarbon type polyol, poly (meth) acrylate type polyol, and animal and vegetable type polyol. In the present invention, "(meth) acrylate" means "acrylate and / or methacrylate".

  The number average molecular weight of the high molecular weight polyol is 500 or more, preferably 1,000 to 40,000, more preferably 1,000 to 20,000, particularly preferably 1,2, in terms of polystyrene by gel permeation chromatography (GPC). It is 000-10,000.

  Examples of polyester polyols include succinic acid, adipic acid, sebacic acid, azelaic acid, terephthalic acid, isophthalic acid, orthophthalic acid, hexahydroterephthalic acid, hexahydroisophthalic acid, hexahydroorthophthalic acid, naphthalene dicarboxylic acid, trimellitic acid, etc. Polycarboxylic acids of the following: anhydrides of these acids or one or more of alkyl esters such as methyl ester and ethyl ester, ethylene glycol, 1,2-propanediol, 1,3-propanediol, 1,2-butanediol, 1,3-butanediol, 1,4-butanediol, 1,5-pentanediol, 1,6-hexanediol, 3-methyl-1,5-pentanediol, neopentyl glycol, 1,8-octanediol, 1,9-nonanediol, diethylene Glycol, dipropylene glycol, 1,4-cyclohexanedimethanol, ethylene oxide (EO) or propylene oxide (PO) adduct of bisphenol A, at least one low molecular weight polyol such as trimethylolpropane, glycerin, pentaerythritol and the like And polyester polyols obtained by the reaction of In addition to these polycarboxylic acids, acid anhydrides, alkyl esters and low molecular weight polyols, low molecular weight polyamines such as butylene diamine, hexamethylene diamine, xylylene diamine and isophorone diamine, monoethanolamine, diethanolamine etc. And polyesteramide polyols obtained by the reaction with one or more of low molecular weight amino alcohols of

  Furthermore, lactone-based polyester polyols obtained by ring-opening polymerization of cyclic ester (lactone) monomers such as ε-caprolactone and γ-valerolactone using low molecular weight polyols, low molecular weight polyamines and low molecular weight amino alcohols as an initiator It can be mentioned.

  As polycarbonate polyols, dehydrochlorination reaction of low molecular weight polyols used in the synthesis of the above-mentioned polyester polyols with phosgene, or transesterification reaction of low molecular weight polyols with diethylene carbonate, dimethyl carbonate, diethyl carbonate, diphenyl carbonate, etc. What is obtained is mentioned.

  As the polyoxyalkylene type polyols, low molecular weight polyols, low molecular weight polyamines, low molecular weight amino alcohols, and polycarboxylic acids other than those used in the synthesis of the above-mentioned polyester polyols; sorbitol, mannitol, sucrose ( Sucrose), low-molecular-weight polyhydric alcohols such as glucose; low-molecular-weight polyhydric alcohols such as bisphenol A and bisphenol F as initiators and cyclic ethers such as ethylene oxide, propylene oxide, butylene oxide, and tetrahydrofuran Polyoxyethylene-based polyols, polyoxypropylene-based polyols, polyoxybutylenes obtained by ring-opening addition polymerization or copolymerization (hereinafter, “polymerization or copolymerization” is referred to as “(co) polymerization”) of one or more of the compounds Polyol, Polio Examples include xytetramethylene-based polyols, poly- (oxyethylene)-(oxypropylene) -random or block copolymer-based polyols, and polyester ether polyols and polycarbonate ether polyols using the above-mentioned polyester polyols and polycarbonate polyols as initiators. . Moreover, the polyol which has the hydroxyl group which made these various polyols and an organic isocyanate compound react with the isocyanate group by the hydroxyl group excess is also mentioned.

  The number of alcoholic hydroxyl groups in the polyoxyalkylene polyol is preferably 2 or more in average in one molecule, more preferably 2 to 4 and particularly preferably 2 to 3.

  The polyoxyalkylene type polyol is a cesium alkoxide such as cesium hydride, cesium methoxide, cesium ethoxide or the like, a cesium compound such as cesium hydroxide, diethyl zinc, iron chloride, metal porphyrin, phosphazenium compound, complex metal cyanide at the time of its production. Complexes can be used as catalysts.

  The polyoxyalkylene-based polyol can be obtained by using a complex metal cyanide complex such as a glyme complex of zinc hexacyanocobaltate or a diglyme complex as a catalyst, and the total unsaturation degree is 0.1 meq / g or less, more preferably 0. .08 meq / g or less, particularly preferably 0.04 meq / g or less, molecular weight distribution [ratio of weight average molecular weight (Mw) to number average molecular weight (Mn) as polystyrene conversion by gel permeation chromatography (GPC) = Mw / Polyoxyalkylene-based polyols having a Mn] of 1.6 or less, particularly 1.0 to 1.3 are preferred. By using such a polyoxyalkylene type polyol, the viscosity of the urethane prepolymer can be reduced, and the rubber physical properties after curing of the curable composition become good.

  In addition, polyoxyalkylene-based monools such as polyoxypropylene-based monools obtained by ring-opening addition polymerization of cyclic ether compounds such as propylene oxide described above using low molecular weight monoalcohols such as methyl alcohol, ethyl alcohol and propyl alcohol as an initiator. The urethane prepolymer can be modified by using an oar.

  The “system” of the above-mentioned polyoxyalkylene type polyol or polyoxyalkylene type monool is 50% by mass or more, more preferably 80% by mass or more, particularly preferably the portion excluding the hydroxyl group in 1 mole of the molecule. If 90% by mass or more is composed of polyoxyalkylene, it means that the remaining part may be modified with ester, urethane, polycarbonate, polyamide, poly (meth) acrylate, polyolefin or the like.

  As a poly (meth) acrylate type polyol, (meth) acrylate monomers containing hydroxyl groups such as hydroxyethyl (meth) acrylate, other (meth) acrylic acid alkyl ester monomers, radical polymerization according to need What copolymerized by adding an initiator is mentioned.

  Examples of hydrocarbon-based polyols include polyolefin polyols such as polybutadiene polyol and polyisoprene polyol; polyalkylene polyols such as hydrogenated polybutadiene polyol and hydrogenated polyisoprene polyol; halogenated polyalkylene polyols such as chlorinated polypropylene polyol and chlorinated polyethylene polyol Can be mentioned.

  Examples of animal and vegetable polyols include castor oil polyols and silk fibroin.

  Any of the above-mentioned active hydrogen-containing compounds can be used alone or in combination of two or more. Among these, high molecular weight polyols are preferable, and polyoxyalkylene type polyols and poly (meth) acrylate type polyols are more preferable, from the viewpoint of good rubber physical properties such as elongation after curing of the curable composition and adhesiveness. Polyoxyalkylene-based polyols are preferred.

式中、ｎは１〜３の整数であり、Ｒは脂肪族炭化水素基である。該脂肪族炭化水素基は、直鎖であってもよく、分岐であってもよい。該脂肪族炭化水素基の炭素数の総数は２０〜６０であり、ｎが２または３の場合、該脂肪族炭化水素基はそれぞれ同一であっても異なっていてもよい。 The ester compound shown by Formula (1) is demonstrated. The ester compound in the present invention is a compound having 1 to 3 ester groups in the compound represented by the formula (1).

In the formula, n is an integer of 1 to 3 and R is an aliphatic hydrocarbon group. The aliphatic hydrocarbon group may be linear or branched. The total number of carbon atoms of the aliphatic hydrocarbon group is 20 to 60, and when n is 2 or 3, the aliphatic hydrocarbon groups may be the same or different.

  As an aliphatic hydrocarbon group, n-butyl group, isobutyl group, n-hexyl group, n-heptyl group, n-octyl group, 2-ethylhexyl group, isooctyl group, n-nonyl group, isononyl group, n-decyl Groups, isodecyl group, dodecyl group, octadecyl group, icosyl group, docosyl group, tetradocosyl group, hexadocosyl group, octadocosyl group.

  The total number of carbon atoms of the aliphatic hydrocarbon group in the compound represented by the formula (1) is 20 to 60, preferably 20 to 40.

  The ester compound represented by the formula (1) can be obtained by reacting an aromatic carboxylic acid or its anhydride with an alcohol.

  Specific examples of aromatic carboxylic acids include benzoic acid, phthalic acid, isophthalic acid, terephthalic acid, trimellitic acid and acid anhydrides thereof. Any of these may be used alone or in combination of two or more.

  As the alcohol, n-butanol, isobutanol, n-hexanol, n-heptanol, n-octanol, 2-ethylhexanol, isooctyl alcohol, n-nonanol, isononanol, n-decanol, isodecanol, dodecanol, tridecanol, tetradec These include norcol, octadecanol, octacosanol, eicosanol, docosanol, tetracosanol, hexacosanol and octacosanol. Any of these may be used alone or in combination of two or more.

  The ester compound represented by the formula (1) is used to reduce the viscosity of the curable composition to improve the workability and to adjust the rubber physical properties of the composition after curing. Moreover, when mix | blending a polyvinyl chloride and a polyurea compound with a curable composition, it is useful as the dispersion solvent. Furthermore, when the ester compound shown by Formula (1) is mix | blended with a curable composition, it is excellent in foaming resistance and softening resistance when thermosetting a curable composition.

The case where the ester compound shown by Formula (1) is used as a dispersion solvent of a polyvinyl chloride or a polyurea compound is demonstrated. Dispersion of polyvinyl chloride (eg, plastic sol) or dispersion of polyurea compound in which polyvinyl chloride or polyurea compound is dispersed in the ester compound represented by the formula (1) imparts thixotropy of the curable composition of the present invention It can be suitably used for the purpose of When a dispersion of polyvinyl chloride or a dispersion of a polyurea compound is used, the shape retention after casting or application of the curable composition is excellent, and sag and slump can be prevented.
Polyvinyl chloride and polyurea compounds generally have high cohesion, and when these particles (powder) are blended in a curable composition and stirred and dispersed, bumps and bumps are generated in the curable composition and the appearance is deteriorated. There are many things to do. In addition, if the dispersion of the polyvinyl chloride or the polyurea compound is insufficient, the thixotropy of the curable composition may also be reduced. Therefore, it is preferable to prepare a dispersion of polyvinyl chloride or polyurea compound by charging polyvinyl chloride or polyurea compound in the ester compound represented by the formula (1) and stirring and dispersing while heating as required. The dispersion of the polyurea compound may be dispersed simultaneously with the synthesis of the polyurea compound. By blending a dispersion of polyvinyl chloride or a polyurea compound into the curable composition, a curable composition having a good appearance and excellent thixotropy without occurrence of bumps and bumps can be obtained.

  The compounding quantity of the ester compound shown by Formula (1) is 3 mass%-40 mass% with respect to the quantity of the whole curable composition, Preferably 5 mass%-30 mass%.

  The curable composition of the present invention may further contain polyvinyl chloride. Polyvinyl chloride is used for the purpose of imparting heat resistance and thixotropy to the curable composition of the present invention. The form of polyvinyl chloride is preferably in the form of particles or powder in view of ease of blending. As described above, when a dispersion (plastic sol) of polyvinyl chloride is formed using an ester compound represented by the formula (1), the dispersibility in preparing a curable composition becomes easy, and it is possible to be thermally cured or after thermally cured The heat resistance of the cured product of the present invention is improved. In addition, thixotropic modification is imparted to the curable composition.

  The method of forming a plastic sol of polyvinyl chloride can be carried out by a conventionally known method. Specifically, for example, polyvinyl chloride and an ester compound represented by the formula (1) are mixed at room temperature, or heated as necessary, and polyvinyl chloride is dispersed in the ester compound represented by the formula (1) to obtain plastic Make a sol. The plastic sol of polyvinyl chloride may be blended with the curable composition after preparing the plastic sol by mixing the ester compound represented by the formula (1) and polyvinyl chloride in advance. In addition, the urethane prepolymer, the ester compound represented by the formula (1), polyvinyl chloride and other components may be mixed to prepare simultaneously a curable composition. Furthermore, the raw material of the above-mentioned urethane prepolymer, the ester compound shown by Formula (1), and polyvinyl chloride may be mixed, and it may produce simultaneously with the synthesis | combination of a urethane prepolymer.

  The blending amount of polyvinyl chloride is 3% by mass to 30% by mass with respect to the total amount of the curable composition.

  The curable composition of the present invention can further contain an oxazolidine compound. The oxazolidine compound is a compound having one or more, preferably 1 to 6, preferably 1 to 3 oxazolidine rings in the molecule, which is a saturated 5-membered heterocyclic ring containing an oxygen atom and a nitrogen atom. The oxazolidine compound reacts with water such as moisture to be hydrolyzed, and the oxazolidine ring forms (regenerates) a secondary amino group and an alcoholic hydroxyl group to function as a latent curing agent for the isocyanate group-containing urethane prepolymer. It is a thing. When the isocyanate group of the urethane prepolymer reacts with water such as moisture, it forms a urea bond and cures. At this time, carbon dioxide gas is also generated, and bubbles may be generated by the carbon dioxide gas in the cured product to cause problems such as deterioration in appearance, breakage of the cured product, and decrease in adhesiveness. On the other hand, when a curable composition in which an isocyanate group-containing urethane prepolymer and an oxazolidine compound are used in combination is reacted with water, water preferentially reacts with the oxazolidine compound, and the oxazolidine ring of the oxazolidine compound is a secondary amino group and alcohol. Form a reactive hydroxyl group (active hydrogen group). Next, since the generated active hydrogen group (in particular, the secondary amino group) preferentially reacts with the isocyanate group, the generation of carbon dioxide gas by the reaction of water and the isocyanate group is suppressed, and the foaming at the curing of the curable composition is performed. It can be prevented. When the curable composition is thermally cured, bubbles occur easily in the cured product because carbon dioxide gas is generated in a short time by the reaction of water and an isocyanate group, but foaming can be suppressed by blending the oxazolidine compound. . In the case of heat curing, the isocyanate group of the urethane prepolymer preferentially reacts with the secondary amino group generated from the oxazolidine ring and the alcoholic hydroxyl group rather than the reaction with water, thereby increasing the crosslinking in the resin and thereby curing the resin. The heat resistance of the object is improved.

  When an aliphatic polyisocyanate or an alicyclic polyisocyanate is used as the organic polyisocyanate used for the isocyanate group-containing urethane prepolymer, the curing of the curable composition may be delayed. When an isocyanate group-containing urethane prepolymer and an oxazolidine compound are used in combination with the curable composition, the curing of the curable composition can be accelerated, and the amount of the curing promoting catalyst described later can be reduced.

  Examples of oxazolidine compounds include urethane bond-containing oxazolidine compounds, ester group-containing oxazolidine compounds, oxazolidine silyl ether compounds, and carbonate group-containing oxazolidine compounds. These oxazolidine compounds can be obtained, for example, by reacting the hydroxyl group of a compound having a hydroxyl group and an oxazolidine ring with the isocyanate group of an organic polyisocyanate or the carboxyl group of an organic carboxylic acid compound. Among these oxazolidine compounds, urethane bond-containing oxazolidine compounds are preferable because of easy production.

  Specific examples of the compound having a hydroxyl group and an oxazolidine ring include N-hydroxyalkyl oxazolidine obtained by the dehydration condensation reaction of a secondary amino group of an alkanolamine and a carbonyl group of a ketone compound or an aldehyde compound. As a method for producing the compound having a hydroxyl group and an oxazolidine ring, 1 mole or more, preferably 1 to 1.5 moles, of a carbonyl group of an aldehyde compound or a ketone compound is preferable to 1 mole of a secondary amino group of alkanolamine. The method is carried out by heating and refluxing in a solvent such as toluene and xylene, and conducting a dehydration condensation reaction while removing by-produced water. Excess aldehyde compounds and ketone compounds can be removed by distillation.

  Examples of alkanolamines include diethanolamine, dipropanolamine and N- (2-hydroxyethyl) -N- (2-hydroxypropyl) amine. Examples of the ketone compound include acetone, diethyl ketone, isopropyl ketone, methyl ethyl ketone, methyl propyl ketone, methyl isopropyl ketone, methyl butyl ketone, methyl isobutyl ketone, methyl tert-butyl ketone, diisobutyl ketone, cyclopentanone and cyclohexanone. Examples of aldehyde compounds include acetaldehyde, propionaldehyde, n-butyraldehyde, isobutyraldehyde, valeraldehyde, isovaleraldehyde, 2-methylbutyraldehyde, n-hexylaldehyde, 2-methylpentyl aldehyde, n-octylaldehyde, 3,5 Aliphatic aldehyde compounds such as 5-trimethylhexyl aldehyde; and aromatic aldehyde compounds such as benzaldehyde, methyl benzaldehyde, trimethyl benzaldehyde, ethyl benzaldehyde, isopropyl benzaldehyde, isobutyl benzaldehyde, methoxy benzaldehyde, dimethoxy benzaldehyde, trimethoxy benzaldehyde and the like. Any of these may be used alone or in combination of two or more.

  Among these, diethanolamine is preferable as the alkanolamine in that it is excellent in easiness of production of a compound having a hydroxyl group and an oxazolidine ring and in foaming resistance when the curable composition cures, and ketone compound or aldehyde compound is preferable. Among them, aldehyde compounds are preferable, and isobutyraldehyde, 2-methylpentyl aldehyde and benzaldehyde are more preferable.

  As a compound having a hydroxyl group and an oxazolidine ring, 2-isopropyl-3- (2-hydroxyethyl) oxazolidine, 2- (1-methylbutyl) -3- (2-hydroxyethyl) oxazolidine, 2-phenyl-3- (2) And-hydroxyethyl) oxazolidine.

  As the urethane bond-containing oxazolidine compound, the isocyanate group of the organic polyisocyanate and the hydroxyl group of the compound having a hydroxyl group and an oxazolidine ring have a molar ratio of isocyanate group / hydroxyl group of 0.9 to 1.2, preferably 0.95 to 1. What is obtained by making it use so that it may become 05, adding a reaction catalyst and an organic solvent as needed, and making it react at the temperature of 50-120 degreeC is mentioned.

  As the organic polyisocyanate used for the production of the urethane bond-containing oxazolidine compound, the same one as used for the production of the above-mentioned isocyanate group-containing urethane prepolymer can be mentioned. Among them, aromatic-aliphatic (aralkyl) polyisocyanate, aliphatic polyisocyanate, and alicyclic polyisocyanate are preferable, and particularly, xylylene diisocyanate, hexamethylene diisocyanate, and isophorone diisocyanate are preferable.

  The ester group-containing oxazolidine compound can be obtained by the reaction of the above-described compound having a hydroxyl group and an oxazolidine ring with a lower alkyl ester of a dicarboxylic acid or a polycarboxylic acid.

  The oxazolidine silyl ether compound is a compound having a hydroxyl group and an oxazolidine ring as described above, trimethoxysilane, tetramethoxysilane, triethoxysilane, dimethoxydimethylsilane, vinyltrimethoxysilane, vinyltriethoxysilane, 3-glycidoxypropyltritriol. It is obtained by a dealcoholization reaction with an alkoxysilane such as methoxysilane or 3-glycidoxypropyltriethoxysilane.

  The carbonate group-containing oxazolidine compound can be obtained by reacting the above-described compound having a hydroxyl group and an oxazolidine ring with a carbonate such as diallyl carbonate using a polyhydric alcohol such as diethylene glycol or glycerin.

  Any of these oxazolidine compounds can be used alone or in combination of two or more.

  The oxazolidine compound preferably does not have an active hydrogen-containing functional group such as an amino group or a hydroxyl group which reacts with the isocyanate group of the urethane prepolymer, or an isocyanate group. This is because when the urethane prepolymer and the oxazolidine compound are used in combination, the viscosity increase of the urethane prepolymer and the antifoaming performance of the oxazolidine compound are reduced. However, in the production of the above-mentioned urethane bond-containing oxazolidine compound, a small amount of active hydrogen-containing functional groups or isocyanate groups may remain in the molecule depending on the selection of molar ratio. In this case, the object of the present invention is not impaired. Can be regarded as not having The amount of the active hydrogen-containing functional group or isocyanate group remaining in the molecule is preferably 0.05 mmol or less, more preferably 0.02 mmol or less, per 1 g of the oxazolidine compound.

  The compounding amount of the oxazolidine compound is 0.1 to 1 mole of active hydrogen of the secondary amino group which is generated (hydrolyzed) by the hydrolysis of the oxazolidine compound with respect to 1 mole of the isocyanate group of the urethane prepolymer, and further 0.3. It is preferable that it is 1 mol, particularly 0.5 to 1 mol.

  The curable composition of the present invention can further contain an acrylic compound. The acrylic compound is a compound having one or more acryloyl groups in the compound, and the carbon-carbon double bond reacts with light or heat. By blending with the curable composition of the present invention, the carbon-carbon double bond reacts at the time of heat curing, and the composition after curing becomes excellent in softening resistance.

  As an acrylic compound, bisphenol-type modified polyacrylates such as bisphenol FEO-modified diacrylate and bisphenol-AEO-modified diacrylate, phenol EO-modified acrylate, nonylphenol EO-modified acrylate, 2-ethylhexyl EO-modified acrylate, N-acryloyloxyethyl hexahydrophthalimide Isocyanuric acid EO modified diacrylate, polypropylene glycol diacrylate, polyethylene glycol diacrylate, trimethylolpropane triacrylate, trimethylolpropane PO modified triacrylate, trimethylolpropane EO modified triacrylate, isocyanuric acid EO triacrylate, pentaerythritol triacrylate, Pentaerythritol tetraacry Over DOO, ditrimethylolpropane tetraacrylate, dipentaerythritol pentaacrylate, dipentaerythritol hexaacrylate, diglycerin EO-modified acrylate. Among these, bisphenol-type modified polyacrylate is preferable, and bisphenol FEO-modified diacrylate and bisphenol AEO-modified diacrylate are preferable. Any of these may be used alone or in combination of two or more.

  The blending amount of the acrylic compound is 0.5 to 20% by mass, preferably 1 to 10% by mass, with respect to the total amount of the curable composition.

  The curable composition of the present invention can contain various additives as needed in addition to the above-described components, as long as the object of the present invention is not impaired. The additive is added to the curable composition and used to improve the properties of the curable composition such as viscosity adjustment, curing acceleration, weather resistance, heat resistance, thixotropy, and adhesiveness. Specific examples thereof include a curing promoting catalyst, a plasticizer, a stabilizer, a filler, a thixotropic agent, an adhesion improver, a storage stability improver (dehydrating agent), a colorant and an organic solvent. Any of these may be used alone or in combination of two or more.

  The curing promoting catalyst is used to accelerate the reaction of the isocyanate group-containing urethane prepolymer with water such as moisture to crosslink and cure. Moreover, when an oxazolidine compound is mix | blended with a curable composition, it is used in order to accelerate | stimulate reaction with the secondary amino group and alcoholic hydroxyl group which were produced | generated from the oxazolidine compound, and the isocyanate group of a urethane prepolymer. Furthermore, the curing promoting catalyst can also be used as a reaction catalyst in the production of the above-mentioned urethane prepolymer. In addition, when it uses as a reaction catalyst at the time of manufacture of a urethane prepolymer, the reaction catalyst which remains in a urethane prepolymer may act as a hardening acceleration | stimulation catalyst of a curable composition.

  Examples of the curing promoting catalyst include metal catalysts and amine catalysts.

  Examples of the metal-based catalyst include salts of metals and organic acids, salts of organic metals and organic acids, and metal chelate compounds. Examples of salts of metals and organic acids include salts of various metals such as tin, bismuth, zirconium, zinc and manganese with organic acids such as octylic acid, neodecanoic acid, stearic acid and naphthenic acid. Specific examples include tin octylate, tin naphthenate, bismuth octylate, and zirconium octylate. As salts of organic metals and organic acids, reactions of dibutyltin dioctoate, dibutyltin dilaurate, dibutyltin diacetate, dibutyltin dimaleate, dibutyltin distearate, dioctyltin dilaurate, dioctyltin diversatate, dibutyltin oxide with phthalic acid ester The thing is mentioned. Examples of metal chelate compounds include dibutyltin bis (acetylacetonate), EXCESTAR C-501 manufactured by Asahi Glass Co., Ltd. which is a tin based chelate compound, zirconium tetrakis (acetylacetonate), titanium tetrakis (acetylacetonate), aluminum tris (acetylacetonate) Nert), aluminum tris (ethylacetoacetate), cobalt acetylacetonate, iron acetylacetonate, copper acetylacetonate, magnesium acetylacetonate, bismuth acetylacetonate, nickel acetylacetonate, zinc acetylacetonate, and manganese acetylacetonate.

  Examples of amine catalysts include tertiary amines. As tertiary amines, triethylamine, tributylamine, triethylenediamine, hexamethylenetetramine, 1,8-diazabicyclo [5,4,0] undecen-7 (DBU), 1,4-diazabicyclo [2,2,2] Examples include octane (DABCO) and salts of these tertiary amines and organic carboxylic acids.

  Any of these curing accelerating catalysts can be used alone or in combination of two or more.

  Among these, salts of metals and organic acids, salts of organic metals and organic acids, metal chelate compounds are preferable, and salts of tin and organic acids, bismuth and the like, because of excellent curability of the curable composition. A salt with an organic acid, a salt of an organic tin and an organic acid, a salt of an organic bismuth and an organic acid, a tin chelate compound, a bismuth chelate compound, and an iron chelate compound are preferable.

  The compounding amount of the curing promoting catalyst is preferably 0.005 to 5 parts by mass, particularly preferably 0.005 to 2 parts by mass with respect to 100 parts by mass of the isocyanate group-containing urethane prepolymer.

  In addition to the above metal-based catalyst and amine-based catalyst, organic carboxylic acid-based catalyst, phosphoric acid ester-based catalyst, p-toluenesulfonyl monoisocyanate, and a reaction product of p-toluenesulfonyl monoisocyanate and water can be used. The reaction product of an organic carboxylic acid catalyst, a phosphoric acid ester catalyst, p-toluenesulfonyl monoisocyanate, a reaction product of p-toluenesulfonyl monoisocyanate and water is an oxazolidine ring of the oxazolidine compound when the oxazolidine compound is added to the curable composition. Promote the hydrolysis of By promoting the hydrolysis of the oxazolidine ring, the generated secondary amino group and the alcoholic hydroxyl group (active hydrogen group) react with the isocyanate group of the urethane prepolymer to accelerate the curing of the curable composition.

  Organic carboxylic acid catalysts include formic acid, acetic acid, propionic acid, caproic acid, oxalic acid, succinic acid, adipic acid, 2-ethylhexanoic acid (octylic acid), octenoic acid, lauric acid, oleic acid, stearic acid and the like Examples thereof include aliphatic carboxylic acids, α, β-unsaturated carboxylic acids such as maleic acid and acrylic acid, and aromatic carboxylic acids such as phthalic acid, benzoic acid and salicylic acid.

  Examples of the phosphoric acid ester type catalyst include a regular phosphoric acid ester compound and a phosphorous acid ester compound. As a regular phosphoric acid ester compound, acidic phosphoric acid ester compounds, such as ethyl acid phosphate, butyl acid phosphate, butoxyethyl acid phosphate, 2-ethylhexyl acid phosphate, oleyl acid phosphate, etc. are mentioned. Examples of phosphorous acid ester compounds include triethyl phosphite, triphenyl phosphite, tris (nonylphenyl) phosphite, tridecyl phosphite, diphenyl mono (2-ethylhexyl) phosphite, triphenyl phosphite such as diphenyl monodecyl phosphite and the like. Ester compounds, phosphorous acid diester compounds such as dilauryl hydrogen phosphite, dioleyl hydrogen phosphite, diphenyl hydrogen phosphite and the like can be mentioned.

  As a reaction product of p-toluenesulfonyl monoisocyanate and water, one prepared by pre-reacting p-toluenesulfonyl monoisocyanate with water before blending into a curable composition, while preparing a curable composition And those reacted with water, and those reacted with water present in the composition after preparation of the curable composition.

  The plasticizer is used to adjust the viscosity of the curable composition and to control the rubber properties of the cured product.

  Resins obtained by etherifying, esterifying, urethanizing hydroxyl groups of polyoxyalkylene-based polyols and polyoxyalkylene-based monools similar to those used for the synthesis of the above-mentioned isocyanate group-containing urethane prepolymer as a plasticizer Examples thereof include hydrocarbon polymers such as butadiene-acrylonitrile copolymer, polychloroprene, polyisoprene or hydrogenated products thereof.

  The stabilizer is used for the purpose of preventing oxidation, photodegradation and thermal degradation of the curable composition to improve weatherability and heat resistance. Examples of the stabilizer include hindered amine light stabilizers, hindered phenol antioxidants, and ultraviolet light absorbers. Moreover, when using polyvinyl chloride for a curable composition, in order to suppress the dehydrochlorination by the heat of polyvinyl chloride, the stabilizer for polyvinyl chloride can be mix | blended. Any of these stabilizers can be used alone or in combination of two or more.

  As the hindered amine light stabilizer, bis (2,2,6,6-tetramethyl-4-piperidyl) sebacate, bis (2,2,6,6-tetramethyl-1 (octyloxy) -4 decanedioate can be used. -Piperidyl) ester, bis (1,2,2,6,6-pentamethyl-4-piperidyl) [[3,5-bis (1,1-dimethylethyl) -4-hydroxyphenyl] methyl] butyl malonate, Methyl 1,2,2,6,6-pentamethyl-4-piperidyl sebacate, bis (1,2,2,6,6-pentamethyl-4-piperidyl) sebacate, 1- [2- [3- (3 ,, 5-di-tert-butyl-4-hydroxyphenyl) propionyloxy] ethyl] -4- [3- (3,5-di-tert-butyl-4-hydroxyphenyl) propionyloxy] Low molecular weight compounds having a molecular weight of less than 1,000 such as 2,2,6,6-tetramethylpiperidine, 4-benzoyloxy-2,2,6,6-tetramethylpiperidine, etc .; dimethyl succinate 1- (2- Hydroxyethyl) -4-hydroxy-2,2,6,6-tetramethylpiperidine polycondensate, poly [{6- (1,1,3,3-tetramethylbutyl) amino-1,3,5-triazine -2,4-diyl} {(2,2,6,6-tetramethyl-4-piperidyl) imino} hexamethylene {(2,2,6,6-tetramethyl-4-piperidyl) imino}], N , N'-bis (3-aminopropyl) ethylenediamine-2,4-bis [N-butyl-N- (1,2,2,6,6-pentamethyl-4-piperidyl) amino] -6-chloro-1 , 3,5-tria Other emissions condensates, ADEKA Corp. STAB LA-63P, molecular weight of 1,000 or more compounds such as LA-68LD and the like.

  As a hindered phenolic antioxidant, pentaerythritol-tetrakis [3- (3,5-di-tert-butyl-4-hydroxyphenyl) propionate], octadecyl-3- (3,5-di-tert-butyl) -4-hydroxyphenyl) propionate, N, N'-hexane-1,6-diylbis [3- (3,5-di-tert-butyl-4-hydroxyphenyl) propioamide], 3,5-di-tert- The C7-C9 alkyl ester of butyl 4-hydroxy benzene propanoic acid, a 2, 4- dimethyl 6- (1-methyl pentadecyl) phenol is mentioned.

  As a UV absorber, benzotriazole-based UV absorbers such as 2- (3,5-di-tert-butyl-2-hydroxyphenyl) -5-chlorobenzotriazole; 2- (4,6-diphenyl-1, Triazine-based UV absorbers such as 3,5-triazin-2-yl) -5-[(hexyl) oxy] phenol; benzophenone-based UV absorbers such as octabenzone; 2,4-di-tert-butylphenyl-3 Benzoate-based ultraviolet absorbers such as 5-di-tert-butyl-4-hydroxybenzoate can be mentioned.

  The compounding amount of the hindered amine light stabilizer, the hindered phenol antioxidant, and the ultraviolet light absorber is 0.1 to 10 parts by mass in total of 100 parts by mass of the isocyanate group-containing urethane prepolymer.

  Stabilizers for polyvinyl chloride include lithium salts such as stearic acid, lauric acid, ricinoleic acid and naphthenic acid, potassium salts, calcium salts, magnesium salts, strontium salts, cadmium salts, metal salts such as barium salts; cadmium, zinc, barium Metal salt stabilizers containing metal components such as calcium, tin, magnesium, sodium and potassium; organotin stabilizers such as laurate organotins, maleate organotins and mercaptide organotins; antimony organotins; phosphorous Acid esters; phenol derivatives; polyhydric alcohols; nitrogen-containing compounds; and stabilizers such as keto compounds.

  The compounding quantity of the stabilizer for polyvinyl chloride is 0.1-10 mass parts with respect to 100 mass parts of polyvinyl chloride.

  The filler is used for the purpose of increasing the amount of the curable composition and reinforcing the physical properties of the cured product. Specifically, mica, kaolin, zeolite, graphite, diatomaceous earth, clay, clay, talc, slate powder, silicic anhydride, fine quartz powder, aluminum powder, zinc powder, synthetic silica such as precipitated silica, calcium carbonate, carbonate Inorganic powdery fillers such as magnesium, alumina, calcium oxide and magnesium oxide; fibrous fillers such as glass fibers and carbon fibers; inorganic balloon fillers such as glass balloons, shirasu balloons, silica balloons and ceramic balloons; Fillers obtained by treating these surfaces with organic substances such as fatty acids; wood powder, walnut shell powder, rice hull powder, pulp powder, cotton chips, rubber powder, fine powder of thermoplastic or thermosetting resin, powder of polyethylene etc. Hollow body, organic balloon-like filling such as Saran micro balloon; Other, magnesium hydroxide or Flame retardant fillers such as aluminum oxide. The particle size of the filler is 0.01 to 1,000 μm.

  The thixotropic agent imparts thixotropy to the curable composition, and for the purpose of preventing the occurrence of drips and slump when the curable composition is used on a vertical surface or inclined surface, or by applying the curable composition to a bead When applied with a comb eye, etc., it is used for the purpose of holding the application shape. Specific examples thereof include inorganic powder modifiers such as finely divided silica and fatty acid-treated calcium carbonate; and organic powder modifiers such as polyurea compounds, organic bentonite and fatty acid amide. Any of these may be used alone or in combination of two or more.

  As finely divided silica, hydrophilic silica and hydrophobic silica can be mentioned. These can be used 1 type or in combination of 2 types.

  Examples of hydrophilic silica include natural silica obtained by finely pulverizing quartz and silica sand, and synthetic silica such as dry silica and wet silica. Dry silica is obtained by burning a silane compound such as silicon tetrachloride in an oxyhydrogen flame, and may be referred to as fumed silica. In addition, wet silica includes precipitated silica which neutralizes an aqueous solution of sodium silicate with an acid and precipitates the silica in the aqueous solution, which may be referred to as white carbon.

  The hydrophobic silica is obtained by reacting the silanol group of hydrophilic silica with a silicone oil, a silane coupling agent, hexamethyldisilazane, chlorosilanes or the like to make its surface hydrophobic.

The BET specific surface area of the finely divided silica is 10 to 500 m ² / g, preferably 50 to 500 m ² / g. The average primary particle size of the finely divided silica is 1 to 100 nm.

  The polyurea compound is a compound having two or more urea groups (-NHCONH-) in the compound, and can be obtained by the reaction of an organic isocyanate compound and an amine compound.

  As an organic isocyanate compound, the organic isocyanate compound similar to what can be used for manufacture of the above-mentioned isocyanate group containing urethane prepolymer is mentioned. Aromatic polyisocyanates are preferred in view of their excellent thixotropic effect.

  An amine compound is a compound having one or more amino groups in the molecule. As an amine compound, the amine which has a primary amino group, the amine which has a secondary amino group, the amine which has a primary amino group and a secondary amino group is mentioned.

  Examples of the amine having a primary amino group include monoamines, diamines and triamines. As monoamines having a primary amino group, butylamine, isobutylamine, hexylamine, heptylamine, 2-ethylhexylamine, octylamine, 3-methoxypropylamine, tetradecylamine, cetylamine, stearylamine, oleylamine, trimethylcyclohexylamine , Benzylamine and aniline. Ethylenediamine, 1,3-diaminopropane, 1,2-diaminopropane, 1,4-diaminobutane, hexamethylenediamine, 1,7-diaminoheptane, trimethylhexamethylenediamine as the diamine having a primary amino group 1,8-diaminooctane, 1,9-diaminononane, 1,10-diaminodecane, 1,11-diaminoundecane, 1,12-diaminododecane, 1,13-diaminotridecane, 1,14-diaminotetradecane, 1,15-diaminopentadecane, 1,16-diaminohexadecane, 1,17-diaminoheptadecane, 1,18-diaminooctadecane, isophorone diamine, diaminodicyclohexyl methane, 3,9-bis (3-aminopropyl)- 2,4,8,10-tetraoxaspiro 5,5) undecane, xylene diamine, phenylene diamine, diaminodiphenylmethane, diaminodiphenyl diethyl phenyl methane, polyoxyethylene diamine, polyoxypropylene diamine. Examples of triamines having a primary amino group include tri (methylamino) hexane. Examples of monoamines having a secondary amino group include diethylamine, dipropylamine, diisopropylamine, dibutylamine, dihexylamine, di-2-ethylhexylamine, diphenylamine, dilaurylamine, distearylamine and methyllaurylamine. As a diamine having a secondary amino group, N, N'-dilaurylpropyldiamine, N, N'-distearylbutyldiamine, N-butyl-N'-laurylethyldiamine, N-butyl-N'-lauryl Propyl diamine and N-lauryl-N'-stearyl butyl diamine are mentioned. Examples of the amine having a primary amino group and a secondary amino group include diethylenetriamine, triethylenetetramine and methylaminopropylamine.

  Any of these amine compounds can be used alone or in combination of two or more. Among these, amines having a primary amino group are preferable, and monoamines having a primary amino group are more preferable.

  Examples of surface-treated calcium carbonate include fatty acid surface-treated calcium carbonate. The fatty acid surface-treated calcium carbonate is obtained by treating the surface of ground calcium carbonate, light calcium carbonate and colloidal calcium carbonate with fatty acids such as fatty acids, fatty acid alkyl esters, fatty acid metal salts and fatty acid organic salts.

  As fatty acids, lauric acid, myristic acid, palmitic acid, stearic acid, oleic acid, beef tallow stearic acid, palm kernel fatty acid, partially cured palm fatty acid, extremely cured palm fatty acid, coconut fatty acid, partially cured coconut fatty acid, extremely cured coconut fatty acid, Palm fatty acid, palm stearic acid, beef tallow fatty acid, partially hardened beef tallow fatty acid, extremely hardened beef tallow fatty acid, soybean fatty acid, partially hardened soybean fatty acid, extremely hardened soybean fatty acid, naphthenic acid, abietic acid, neoabietic acid. Examples of metal salts include sodium salts, potassium salts, calcium salts and aluminum salts. Organic salts include ammonium salts.

  Commercial products of fatty acid surface-treated calcium carbonate include Sherets 200, Calfine 200, Calfine 200M, Calfine 500, Calfine N-40, Calfine N-350, Maruo Calcium Co., Ltd .; White matted flower CCR, white matted flower CCR-S, white matted flower CCR-B, VIGOT-10, VIGOT-15, Viscolite-SV, Viscolite-OS, Viscolite EL-20; NCC # 3010, NCC # 1010 from Nitto Powder Co., Ltd. . Any of these may be used alone or in combination of two or more. Among these, calcium carbonate surface-treated with a fatty acid or a fatty acid metal salt is preferable in that the thixotropic effect is high.

The particle size of the fatty acid surface-treated calcium carbonate is 0.01 to 1 μm, preferably 0.01 to 0.3 μm. The particle size of fatty acid surface-treated calcium carbonate can be determined as the primary particle size measured by an electron microscope. The BET specific surface area of the fatty acid surface-treated calcium carbonate is 5 to 200 m ² / g, preferably 10 to 60 m ² / g. When the particle size is less than 0.01 μm or the BET specific surface area exceeds 200 m ² / g, the viscosity of the curable composition becomes high and the workability is deteriorated. When the particle size is more than 1 μm or the BET specific surface area is less than 5 m ² / g, the thixotropic effect is reduced.

  The compounding amount of the surface-treated calcium carbonate is 1 to 200 parts by mass, preferably 5 to 150 parts by mass with respect to 100 parts by mass of the isocyanate group-containing urethane prepolymer.

  The adhesion improver is used for the purpose of improving the adhesion of the curable composition. Specifically, various coupling agents such as silanes, aluminums and zircoaluminates or partial hydrolytic condensates thereof can be mentioned. Among these, silane coupling agents or partial hydrolytic condensates thereof are preferable because of their excellent adhesion.

  As a silane coupling agent, vinyltrimethoxysilane, vinylmethyldimethoxysilane, 3- (meth) acryloxypropyltrimethoxysilane, 3- (meth) acryloxypropylmethyldimethoxysilane, 3-mercaptopropyltrimethoxysilane, 3-aminopropyltrimethoxysilane, N- (2-aminoethyl) -3-aminopropylmethyldimethoxysilane, N- (2-aminoethyl) -3-aminopropyltrimethoxysilane, N- (2-aminoethyl) Low molecular weight compound having a molecular weight of 500 or less, preferably 400 or less, containing an alkoxysilyl group such as -3-aminopropylmethyldiethoxysilane, 3-glycidoxypropyltrimethoxysilane, 3-glycidoxypropylmethyldiethoxysilane and the like Or these sila Compounds having a molecular weight 200 to 3,000 are exemplified by one or more partially hydrolyzed condensate of the system a coupling agent. Any of these may be used alone or in combination of two or more.

  The storage stability improver (dehydrating agent) is used for the purpose of improving the storage stability of the curable composition. Specific examples thereof include vinyltrimethoxysilane, calcium oxide and p-toluenesulfonyl monoisocyanate which react with water present in the curable composition to act as a dehydrating agent. Any of these may be used alone or in combination of two or more.

  A coloring agent is used for the purpose of coloring a curable composition and providing a design. Specific examples include inorganic pigments such as titanium oxide and iron oxide, organic pigments such as copper phthalocyanine, and carbon black. Any of these may be used alone or in combination of two or more.

  The organic solvent is used to lower the viscosity of the curable composition and to improve the extrusion and coating workability. As the organic solvent, an isocyanate group-containing urethane prepolymer, an ester compound represented by the formula (1), polyvinyl chloride, an oxazolidine compound, and an organic solvent which does not react with the additive can be used without particular limitation. Specifically, ester solvents such as ethyl acetate; ketone solvents such as methyl ethyl ketone; aliphatic solvents such as n-hexane; naphthene solvents such as methyl cyclohexane, ethyl cyclohexane and dimethyl cyclohexane; and aromatic substances such as toluene and xylene Group solvents. Any of these may be used alone or in combination of two or more. The organic solvent may be used in the synthesis of the isocyanate group-containing urethane prepolymer, and may be used in the preparation of the curable composition.

The curable composition of the present invention can be used as a one-component curable composition because it is cured or crosslinked by reaction with water such as moisture or heat. The curable composition of the present invention can also be used as a two-component curable composition having as a main component an active hydrogen-containing compound such as a polyamine or a polyol as a curing agent. It is preferable to use the composition as a one-component curable composition because it does not require time-consuming mixing of the main agent and the curing agent, and there is no occurrence of curing failure due to mixing error, and the workability is excellent.
Furthermore, since the curable composition of the present invention is excellent in foaming resistance and softening resistance at the time of heat curing, it can be used as a thermosetting composition. In the present invention, the thermosetting composition is a composition which can be cured at 100 ° C. or more and does not cause a large decrease in physical properties (foaming or softening) after thermosetting.

  The curable composition of the present invention is also excellent in adhesion to a metal plate (e.g., steel plate) and adhesion to a paint, so metal plate joints of vending machines, home appliances, industrial equipment, automobiles, trains, heavy machinery etc. It can be used for Moreover, it can be used as an undercoat at the time of applying a paint to the surface of metal parts, such as a vending machine, household appliances, industrial equipment, cars, trains, heavy machinery and the like. The curable composition of the present invention can also be cured simultaneously with the step of applying a top coat and heating and drying and curing the paint after being placed or applied to the surface of a metal plate or metal site.

  Hereinafter, the present invention will be described in more detail by way of examples and the like, but the present invention is not construed as being limited thereto.

Synthesis Example 1 Isocyanate Group-Containing Urethane Prepolymer PU-1
47.0 g of an organic solvent (Exsol D110, manufactured by Exxon Mobil) while flowing nitrogen gas into a reaction vessel equipped with a stirrer, thermometer, nitrogen seal tube and heating / cooling device, polyoxypropylene triol (PML-S 3008, Asahi Glass Co., Ltd. Co., Ltd., 800.0 g of a number average molecular weight of 8,370 and a total unsaturation degree of 0.005 meq / g) are charged, and 78.7 g of isophorone diisocyanate (a molecular weight of 222.2, manufactured by Togsa Japan Co., Ltd.) while stirring, and octyl 0.1 g of acid tin (manufactured by Nitto Kasei Co., Ltd.) was charged and reacted at 70 to 80 ° C. for reaction. The reaction was terminated when the isocyanate group content by titration was 1.85 mass% or less of the theoretical value (measured value 1.79 mass%), and cooled to synthesize an isocyanate group-containing urethane prepolymer PU-1. The isocyanate group-containing urethane prepolymer PU-1 had a viscosity of 8,780 mPa · s at 25 ° C., and was liquid at normal temperature.

Synthesis Example 2 Urethane Bond-Containing Oxazolidine Compound O-1
In a reaction vessel equipped with a stirrer, thermometer, nitrogen seal tube, ester tube, heating / cooling device, 435.0 g of diethanolamine (molecular weight 105) and 183.0 g of toluene are charged, and while stirring, isobutyraldehyde (molecular weight 72.1) 328.0 g was charged, heated to 110 to 150 ° C. under a nitrogen gas flow, reflux dehydration reaction was continued, and by-product water (74.5 g) was taken out of the system. After completion of the reaction, the reaction product was further heated under reduced pressure (50 to 70 hPa) to remove toluene and unreacted isobutyraldehyde to obtain an intermediate reaction product N-hydroxyethyl-2-isopropyloxazolidine.
Then, 348.0 g of hexamethylene diisocyanate (molecular weight: 168) is further added to 659.0 g of the obtained N-hydroxyethyl-2-isopropyloxazolidine, and the mixture is heated at 80 ° C. for 8 hours, and the NCO content by titration is 0. When it became 0 mass%, it was considered as the reaction end point to obtain a urethane bond-containing oxazolidine compound O-1 having two oxazolidine rings in the molecule. The urethane bond-containing oxazolidine compound O-1 was liquid at normal temperature.

Preparation Example 1
A solution of 100.0 g of diphenylmethane diisocyanate in 300.0 g of tris (2-ethylhexyl) trimellitate and a solution of 55.0 g of n-butylamine in 320.0 g tris (2-ethylhexyl) trimellitate The reaction was conducted at normal temperature to obtain a dispersion paste P-1 of the polyurea compound. Dispersion paste P-1 is composed of 20% by mass of the polyurea compound and 80% by mass of tris (2-ethylhexyl) trimellitate.
Preparation Example 2
A solution of 100.0 g of diphenylmethane diisocyanate dissolved in 300.0 g of diisodecyl phthalate and a solution of 55.0 g of n-butylamine dissolved in 320.0 g of diisodecyl phthalate are reacted at normal temperature to obtain a dispersion paste of polyurea compound P- I got two. Dispersion paste P-2 is composed of 20% by mass of the polyurea compound and 80% by mass of diisodecyl phthalate.
Preparation Example 3
A solution of 100.0 g of diphenylmethane diisocyanate in 300.0 g of bis (2-ethylhexyl) phthalate and a solution of 55.0 g of n-butylamine in 320.0 g of bis (2-ethylhexyl) phthalate at normal temperature It was made to react and dispersion paste P-3 of a polyurea compound was obtained. Dispersion paste P-3 comprises 20% by mass of the polyurea compound and 80% by mass of bis (2-ethylhexyl) phthalate.
Preparation Example 4
A solution of 100.0 g of diphenylmethane diisocyanate in 300.0 g of diisononyl phthalate and a solution of 55.0 g of n-butylamine in 320.0 g of diisononyl phthalate are reacted at room temperature to obtain a dispersion paste of polyurea compound P- I got four. Dispersion paste P-4 is composed of 20% by mass of the polyurea compound and 80% by mass of diisononyl phthalate.
Preparation Example 5
A solution of a solution of 100.0 g of diphenylmethane diisocyanate in 300.0 g of diisononyl adipate and a solution of 55.0 g of n-butylamine in 320.0 g of diisononyl adipate are reacted at room temperature to obtain a dispersion paste of polyurea compound P- I got five. Dispersion paste P-5 comprises 20% by mass of the polyurea compound and 80% by mass of diisononyl adipate.

Example 1
In a heating / cooling apparatus and a mixing vessel with a nitrogen seal pipe, under nitrogen flow, 100.0 g of the isocyanate group-containing urethane prepolymer PU-1 obtained in Synthesis Example 1 and 16.1 g of tris (2-ethylhexyl) trimellitate Obtained in Preparation Example 1 of 108.0 g of ground calcium carbonate (Whiteton B, manufactured by Shiroishi Calcium Co., Ltd.) dried in advance at 90 to 100 ° C. to a moisture content of 0.05% by mass or less 105.6 g of dispersion paste P-1 of the polyurea compound, 48.3 g of polyvinyl chloride (VESTOLIT E 7031, manufactured by VESTOLIT), and 1.4 g of a stabilizer for polyvinyl chloride (ADEKA STAB SC-308 E, manufactured by ADEKA) The mixture was stirred and mixed until the contents became uniform. At this point polyvinyl chloride has become a plastic sol. Next, 13.2 g of an acrylic compound (ALONIX M 211 B, bisphenol AEO modified (n is about 2) diacrylate, manufactured by Toagosei Co., Ltd.), a hindered phenolic antioxidant (IRGANOX 1010, manufactured by BASF AG), 4 g, 1.4 g of a hindered amine light stabilizer (Sanol LS-292, manufactured by Sanko), 8.6 g of the urethane bond-containing oxazolidine compound O-1 obtained in Synthesis Example 2 are charged, and the contents become uniform Stir until mixed. Then, 0.02 g of iron (III) acetylacetonate and 0.5 g of p-toluenesulfonyl isocyanate are charged, and the contents are stirred, mixed until uniform, degassed under reduced pressure, filled and sealed in a container, and cured Sex composition (sealing material composition) was prepared.
Example 2
In Example 1, 16.1 g of diisodecyl phthalate is introduced instead of tris (2-ethylhexyl) trimellitate, and 105.6 g of dispersion paste P-2 of polyurea compound is introduced instead of dispersion paste P-1 of polyurea compound. A curable composition (sealing material composition) was prepared in the same manner as described above.
Comparative Example 1
In Example 1, 16.1 g of bis (2-ethylhexyl) phthalate in place of tris (2-ethylhexyl) trimellitate, and dispersion paste P-3 of polyurea compound in place of dispersion paste P-1 of polyurea compound. The same operation was carried out except that 105.6 g was charged, to prepare a curable composition (sealant composition).
Comparative Example 2
In Example 1, 16.1 g of diisononyl phthalate was used instead of tris (2-ethylhexyl) trimellitate, and 105.6 g of polyurea compound dispersion paste P-4 was used instead of polyurea compound dispersion paste P-1. A similar operation was performed except for the preparation of a curable composition (sealant composition).
Comparative Example 3
In Example 1, instead of tris (2-ethylhexyl) trimellitate, 16.1 g of diisononyl adipate and 105.6 g of dispersion paste P-5 of a polyurea compound instead of dispersion paste P-1 of a polyurea compound were charged. A similar operation was performed except for the preparation of a curable composition (sealant composition).

  The compositions of the curable compositions of Examples 1 to 2 and Comparative Examples 1 to 3 are shown in Table 1.

  The following performance test was done using the curable composition of Examples 1-2 and Comparative Examples 1-3. The performance test results of the curable composition are shown in Table 2.

Performance test [foam resistance]
After placing the curable composition on the surface of alumite aluminum in a bead shape (semi-elliptical cross section) of width 5 mm × height 3 mm × length 100 mm, 0.5 hour, 24 hours or at 23 ° C. and 50% RH It was cured for 72 hours and used as a test body. After each aging, the specimen was placed in an oven set at 180 ° C. for 45 minutes to be thermally cured. After heat curing, the test body was allowed to stand at 23 ° C. and 50% RH for 24 hours. The appearance of the cured product and the foaming state inside were visually observed and the following evaluation was performed. The observation of the foaming state inside was cut in the longitudinal direction so as to be sliced with a cutter from the position of height 1.5 mm of the cured product, and the cross section of the cured product was visually observed.
○: There is no blistering in the appearance of the cured product, no foaming is observed inside. Δ: There is no blistering in the appearance of the cured material, but a lot of foaming is observed inside. ×: There is blistering in the appearance of the cured material. There is a lot of foaming in the [hardness]
After placing the curable composition on the surface of alumite aluminum in a bead shape (semi-elliptical cross section) of width 5 mm × height 3 mm × length 100 mm, 0.5 hour, 24 hours or at 23 ° C. and 50% RH It was cured for 72 hours and used as a test body. After each aging, the specimen was placed in an oven set at 180 ° C. for 45 minutes to be thermally cured. After heat curing, the test body was allowed to stand at 23 ° C. and 50% RH for 24 hours. The hardness of the cured product (3 mm in height) was measured with a type A durometer.

表２に示すように、実施例１〜２の硬化性組成物は、１８０℃の加熱養生において、発泡や軟化は認められず、熱硬化時の耐発泡性や耐軟化性に優れていることが分かる。一方、比較例１〜３の硬化性組成物は、１８０℃の加熱養生において、発泡や硬度低下（軟化）が認められ、熱硬化時の耐発泡性や耐軟化性が悪いことが分かる。
常態養生を行い加熱養生しない場合、実施例１〜２および比較例１〜３の硬化性組成物の耐発泡性や耐軟化性は良好である。比較例１〜３の硬化性組成物は、１８０℃の加熱養生（熱硬化時）において、熱の影響により発泡や硬度低下（軟化）が生じたと考えられる。

As shown in Table 2, in the heat curing at 180 ° C., the curable compositions of Examples 1 to 2 were found to be neither foam nor softening, and excellent in foaming resistance and softening resistance at the time of heat curing. I understand. On the other hand, in the curable compositions of Comparative Examples 1 to 3, foaming and a decrease in hardness (softening) are recognized during heat curing at 180 ° C., and it is found that the foam resistance and softening resistance at the time of heat curing are poor.
When normal curing is not performed and heat curing is not performed, the foaming resistance and the softening resistance of the curable compositions of Examples 1 to 2 and Comparative Examples 1 to 3 are good. It is considered that the curable compositions of Comparative Examples 1 to 3 caused foaming and hardness reduction (softening) due to the influence of heat during heat curing (at the time of heat curing) at 180 ° C.

  The curable composition of the present invention is useful as a thermosetting composition because it is excellent in foaming resistance and softening resistance at the time of heat curing. Moreover, the curable composition of this invention can be used as a sealing material composition, a waterproof material composition, an adhesive composition, and a coating material composition.

Claims (6)

A curable composition comprising an isocyanate group-containing urethane prepolymer and an ester compound represented by the formula (1).

(Wherein n is an integer of 1 to 3 and R is an aliphatic hydrocarbon group. The aliphatic hydrocarbon group may be linear or branched, and may be branched. Aliphatic The total number of carbon atoms in the hydrocarbon group is 20 to 60, and when n is 2 or 3, the aliphatic hydrocarbon groups may be the same or different.)   The curable composition according to claim 1, wherein the compounding amount of the ester compound represented by the formula (1) is 3 to 40% by mass of the whole of the curable composition.   The curable composition according to claim 1, further comprising polyvinyl chloride.   Furthermore, the curable composition as described in any one of Claims 1-3 containing an oxazolidine compound.   Furthermore, it contains one or more additives selected from a curing accelerating catalyst, a plasticizer, a stabilizer, a filler, a thixotropic agent, an adhesion improver, a storage stability improver, a colorant and an organic solvent. The curable composition as described in any one of the Claims 1-4 characterized by these.   It is a thermosetting composition, The curable composition as described in any one of Claims 1-5 characterized by the above-mentioned.