JP4767076B2 - Curable composition - Google Patents

Description

  The present invention relates to a curable composition containing an isocyanate group-containing urethane prepolymer.

  Conventionally, it contains an isocyanate group-containing urethane prepolymer as a curing component as a waterproofing sealant for exterior wall joints of buildings, resin sheets such as vinyl chloride sheets, adhesives or coating floors for building members such as tiles and wooden boards, etc. Excellent properties such as ease of work, high adhesiveness after curing, and wide range of rubber elastic properties after curing from low modulus to high modulus (high elongation to low elongation) Widely used.

  The curable composition containing the isocyanate group-containing urethane prepolymer includes a two-component curable composition or a multi-component curable composition in which a main agent and a curing agent are mixed and cured at the time of construction, and a curable composition. One-component moisture-curing type curable composition that utilizes the isocyanate group of the isocyanate group-containing urethane prepolymer reacts with moisture and proceeds with curing by exposing it to moisture (humidity) in the atmosphere after construction. There is no need to mix the main agent and curing agent at the time of construction work, and there is no measurement failure due to mismeasurement of the main agent and the curing agent or poor curing due to improper mixing. The amount of sex composition used is increasing year by year.

  However, in a one-component moisture-curing curable composition containing an isocyanate group-containing urethane prepolymer, when the isocyanate group concentration is high or the curing speed is increased, the isocyanate group is separated from moisture (humidity) in the atmosphere. When reacting and curing, the amount of carbon dioxide generated increases or suddenly carbon dioxide is generated, resulting in bubbles of carbon dioxide inside the cured product, resulting in deterioration in appearance and deterioration of rubber tensile properties such as elongation. There are problems that cause problems such as a decrease in adhesive strength.

  As a method for preventing foaming due to this carbon dioxide gas, when the isocyanate group-containing urethane prepolymer is mixed with a compound having an oxazolidine ring in advance as a composition, and the isocyanate group-containing urethane prepolymer is brought into contact with moisture during construction, Before the isocyanate group reacts with moisture to generate carbon dioxide, the active hydrogen group of the secondary amine produced by the reaction of the oxazolidine compound with moisture reacts with the isocyanate group of the isocyanate group-containing urethane prepolymer to react with urea. There is a method of using a compound having an oxazolidine ring as a so-called latent curing agent, which is cured without causing foaming by carbon dioxide gas. As a method of using this compound having an oxazolidine ring, for example, a room temperature at which a desired curing rate is obtained by suppressing foaming in which a urethane prepolymer is blended with a compound having an oxazolidine ring and a ring-opening promoting compound of the oxazolidine ring. A curable polyurethane composition, an isocyanate group-containing urethane prepolymer, a compound having an oxazolidine ring, and an acidic substance having a specific acid dissociation index pKa are not accompanied by foaming, have good curability, and Moisture-curing urethane compositions with excellent heat degradation properties have been proposed (see, for example, Patent Document 1 and Patent Document 2).

  However, when a compound having an oxazolidine ring is blended with an isocyanate group-containing urethane prepolymer to form a composition, the addition of a curing accelerator to increase the curing speed reduces the stability during storage, and the curing accelerator. Is not added, the storage stability is improved, but there is a problem that the curing rate is lowered, and it is extremely difficult to achieve both high curing rate and excellent storage stability. But it is still insufficient.

JP-A-9-169829 JP-A-9-278857

  In view of the above-mentioned conventional problems, the invention of the present invention is a curable composition containing an isocyanate group-containing urethane prepolymer and a compound having an oxazolidine ring, and has excellent storage without causing foaming in the cured product. An object of the present invention is to provide a curable composition having both stability and a high curing rate.

  As a result of intensive studies to solve the above-mentioned problems, the present inventors have added a carbonate ester compound to a curable composition containing an isocyanate group-containing urethane prepolymer, a compound having an oxazolidine ring, and a curing accelerator. It has been found that, by blending, both excellent storage stability and high curing speed can be achieved, and the present invention has been completed.

  That is, the present invention relates to (1) a curable composition containing an isocyanate group-containing urethane prepolymer (A), a compound (B) having an oxazolidine ring, a curing accelerator (C), and a carbonate compound (D). (2) The compound (B) having an oxazolidine ring is preferably a urethane bond-containing oxazolidine compound, and (3) the curing accelerator (C) is a metal catalyst, phosphoric acid One or two or more selected from the group consisting of ester compounds, organic carboxylic acid compounds, p-toluenesulfonyl isocyanate and a reaction product of p-toluenesulfonyl isocyanate and moisture are preferred, and (4) the carbonate ester As the compound (D), dimethyl carbonate is preferred, and the present invention further comprises (5) The curable composition according to any one of (1) to (4) is further blended with an additive (E). (6) The additive (E) is preferably a polymer dilution resin. It is.

  In the present invention, a curable composition comprising an isocyanate group-containing urethane prepolymer (A), a compound (B) having an oxazolidine ring, a curing accelerator (C), and a carbonate compound (D) is provided. More preferred.

  Each component used in the curable composition of the present invention will be described in detail below.

First, the isocyanate group-containing urethane prepolymer (A) component will be described.
The isocyanate group-containing urethane prepolymer (A) is obtained by reacting an organic isocyanate compound and an active hydrogen-containing compound with active hydrogen (group) under an isocyanate group excess condition, and is a curable composition of the present invention. In, it is used as a hardening component.

  Examples of organic isocyanate compounds include organic polyisocyanates and organic monoisocyanates that are optionally used for modifying isocyanate group-containing urethane prepolymers. Further, as organic polyisocyanates, isocyanate groups are bonded to aromatic hydrocarbons. Aromatic organic polyisocyanates and broadly defined aliphatic organic polyisocyanates in which isocyanate groups are bonded to aliphatic hydrocarbons (this includes aromatic aliphatic organic polyisocyanates and narrowly defined aliphatic organic polyisocyanates) Etc.).

  Examples of the aromatic organic polyisocyanate include diphenylmethane diisocyanates (MDIs) such as phenylene diisocyanate, diphenyl diisocyanate, naphthalene diisocyanate, 4,4′-diphenylmethane diisocyanate, 2,4′-diphenylmethane diisocyanate, or a mixture thereof. Examples include toluene diisocyanates (TDIs) such as 2,4-toluene diisocyanate, 2,6-toluene diisocyanate or mixtures thereof, and diphenyl ether diisocyanate.

  Examples of the araliphatic organic polyisocyanate include xylylene diisocyanate, and the narrowly defined aliphatic organic polyisocyanate includes aliphatic polyisocyanate and alicyclic polyisocyanate. Examples include methylene diisocyanate, pentamethylene diisocyanate, propylene diisocyanate, and butylene diisocyanate. Examples of the alicyclic polyisocyanate include cyclohexane diisocyanate, methylene bis (cyclohexyl isocyanate), and isophorone diisocyanate.

  In addition, carbodiimide-modified products, biuret-modified products, allophanate-modified products, dimers, trimers, or polymethylene polyphenyl polyisocyanates (crude MDI, polymeric MDI) and the like of these diisocyanates may be mentioned. A combination of more than one species can be used. Of these, aliphatic organic polyisocyanates in a broad sense are preferable from the viewpoint of excellent antifoaming properties and weather resistance, and xylylene diisocyanate, hexamethylene diisocyanate, and isophorone diisocyanate are more preferable, and isophorone diisocyanate is particularly preferable.

  Moreover, as modification | denaturation of an isocyanate group containing urethane prepolymer, the organic monoisocyanate used depending on the case includes aliphatic monoisocyanates such as n-butyl monoisocyanate, n-hexyl monoisocyanate, and n-octadecyl monoisocyanate.

  As the active hydrogen-containing compound, in addition to a polymer polyol or polymer polyamine, a low molecular polyol, a low molecular amino alcohol, a low molecular polyamine, or a modification of an isocyanate group-containing urethane prepolymer as a chain extender used in some cases. Examples thereof include a high molecular weight polymer and a low molecular weight monool.

  Examples of the polymer polyol include polyester polyol, polycarbonate polyol, polyoxyalkylene-based polyol, hydrocarbon-based polyol, animal and plant-based polyol, these copolyols, or a mixture of two or more thereof.

  The number average molecular weight in terms of polystyrene by gel permeation chromatography of the polymer polyol is 500 or more, more preferably 1,000 to 100,000, even more preferably 1,000 to 30,000, and particularly preferably 1,000 to 20,000. . If the number average molecular weight is less than 500, rubber elastic properties such as elongation after curing of the resulting curable composition deteriorate, and if it exceeds 100,000, the viscosity of the resulting isocyanate group-containing urethane prepolymer becomes too high, Since workability deteriorates, it is not preferable.

  Examples of the polyester polyol include succinic acid, adipic acid, sebacic acid, azelaic acid, terephthalic acid, isophthalic acid, orthophthalic acid, hexahydroterephthalic acid, hexahydroisophthalic acid, hexahydroorthophthalic acid, naphthalenedicarboxylic acid, triphthalic acid, and the like. One or more of polycarboxylic acids such as merit acid, acid esters, or acid anhydrides, 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, , 4-cyclohexanedimethanol, ethylene oxide or propylene oxide adduct of bisphenol A, low molecular polyols such as trimethylolpropane, glycerin, pentaerythritol, butylenediamine, hexamethylenediamine, xylylenediamine, isophoronediamine, etc. Examples thereof include polyester polyols or polyester amide polyols obtained by a dehydration condensation reaction with one or more low molecular amino alcohols such as low molecular polyamines, monoethanolamine, and diethanolamine.

  Also, for example, lactone polyesters obtained by ring-opening polymerization of cyclic ester (lactone) monomers such as ε-caprolactone and γ-valerolactone using low molecular polyols, low molecular polyamines, and low molecular amino alcohols as initiators. A polyol is mentioned.

  Examples of the polycarbonate polyol include dehydrochlorination reaction of low molecular polyols and phosgene used for the synthesis of the above-described polyester polyol, or esters of the low molecular polyols with diethylene carbonate, dimethyl carbonate, diethyl carbonate, diphenyl carbonate, and the like. What is obtained by an exchange reaction is mentioned.

  Examples of the polyoxyalkylene polyol include low molecular polyols, low molecular polyamines, low molecular amino alcohols, polycarboxylic acids, sorbitol, mannitol, sucrose used for the synthesis of the above-described polyester polyols. 1 or more of cyclic ether compounds such as ethylene oxide, propylene oxide, butylene oxide, and tetrahydrofuran using one or more of low molecular weight polyhydric alcohols such as saccharides such as glucose and low molecular weight polyphenols such as bisphenol A and bisphenol F as initiators A polyoxyethylene-based polyol, a polyoxypropylene-based polyol, a polyoxybutylene-based polyol, a polyoxyethylene, which is obtained by ring-opening addition polymerization or copolymerization (hereinafter, “polymerization or copolymerization” is referred to as (co) polymerization). Ramechiren polyols, poly - (oxyethylene) - (oxypropylene) - random or block copolymer polyols, further polyester polyether polyol initiator polyester polyols and polycarbonate polyols described above, such as polycarbonate polyether polyols. Moreover, the polyol which made these various polyols and organic isocyanate react by hydroxyl group excess with respect to an isocyanate group, and made the molecular terminal a hydroxyl group is also mentioned.

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

  Furthermore, the polyoxyalkylene-based polyol is produced at the time of production thereof by cesium hydride, cesium methoxide, cesium alkoxide such as cesium ethoxide, cesium-based compounds such as cesium hydroxide, diethyl zinc, iron chloride, metalloporphyrin, phosphazenium compound, The total unsaturation obtained by using a double metal cyanide complex such as a double metal cyanide complex such as a zinc hexacyanocobaltate glyme complex or diglyme complex as a catalyst is 0.1 meq / g or less. 07 meq / g or less, particularly 0.04 meq / g or less is preferable, and molecular weight distribution [ratio of weight average molecular weight (Mw) and number average molecular weight (Mn) in terms of polystyrene by gel permeation chromatography (GPC) = Mw / Mn] is 1.6 or less, especially 1.0 Having a narrow 1.3, viscosity of the resulting diisocyanate sulfonate group-containing urethane prepolymer can reduce, and rubber elasticity properties after curing of the resulting cured composition is preferable in that is good.

  In addition, for modification of an isocyanate group-containing urethane prepolymer, polyoxyl obtained by ring-opening addition polymerization of a cyclic ether compound such as propylene oxide using a low-molecular monoalcohol such as methyl alcohol, ethyl alcohol or propyl alcohol as an initiator. In some cases, polyoxyalkylene monools such as propylene monools may be used.

  The “system” such as the polyoxyalkylene polyol or polyoxyalkylene monool is 50% by mass or more, more preferably 80% by mass or more, particularly preferably 90% by mass of the portion excluding the hydroxyl group in 1 mol of the molecule. % Or more is composed of polyoxyalkylene, which means that the remaining part may be modified with ester, urethane, polycarbonate, polyamide, poly (meth) acrylate, polyolefin, etc., except for hydroxyl groups. Most preferably, 95% by mass or more of the molecules consist of polyoxyalkylene.

  Examples of the hydrocarbon-based polyol include polyolefin polyols such as polybutadiene polyol and polyisoprene polyol, polyalkylene polyols such as hydrogenated polybutadiene polyol and hydrogenated polyisoprene polyol, and halogenated poly such as chlorinated polypropylene polyol and chlorinated polyethylene polyol. Examples include alkylene polyols.

  As a poly (meth) acrylate-based polyol, a (meth) acrylate monomer containing a hydroxyl group such as hydroxyethyl (meth) acrylate and another (meth) acrylic acid alkyl ester monomer are used as radical polymerization initiators. And those copolymerized in the presence or absence of.

  Examples of animal and plant-based polyols include castor oil-based diols.

  As the chain extender, in addition to the low molecular weight polyols, polyamines and amino alcohols used in the synthesis of the polyester polyol, the polyoxyalkylene polyol described above has a low molecular weight with a number average molecular weight of less than 500, Or the mixture of these 2 or more types is illustrated.

  The compounds mentioned as the active hydrogen-containing compound can be used alone or in combination of two or more, but among these, the rubber elastic properties and adhesiveness of the resulting curable composition are good, High molecular polyols are preferred, polyoxyalkylene polyols are more preferred, and polyoxypropylene polyols are most preferred.

  The isocyanate group-containing urethane prepolymer in the present invention can be synthesized by either a batch charge reaction method or a multistage charge reaction method, but it is necessary to leave an isocyanate group in the molecule of the prepolymer. The isocyanate group / active hydrogen (group) equivalent ratio of the isocyanate group of the organic isocyanate compound to the polymer polyol, and optionally the active hydrogen (group) of the chain extender is 1.1 to 5.0 / 1.0. Preferably, 1.3 to 2.5 / 1.0 is more preferable. The isocyanate group-containing urethane prepolymer thus obtained preferably has an isocyanate group content of 0.1 to 15.0% by mass, particularly preferably 0.3 to 10.0% by mass, and most preferably 0.4 to 5.0% by mass. When the isocyanate group content is less than 0.1% by mass, the molecular weight becomes too large, the viscosity increases, and the workability decreases. Moreover, since there are few crosslinking points in a prepolymer, sufficient adhesiveness cannot be obtained. If the isocyanate group content exceeds 15.0% by mass, it is difficult to prevent foaming due to carbon dioxide gas, which is not preferable.

Next, the compound (B) having an oxazolidine ring will be described.
The compound (B) having an oxazolidine ring is a compound having 1 or more, preferably 2 to 6 oxazolidine rings in the molecule, which is a saturated 5-membered heterocyclic ring containing an oxygen atom and a nitrogen atom. Acts as a latent curing agent for isocyanate group-containing urethane prepolymer (A) by reacting with moisture (humidity) and undergoing hydrolysis, and the oxazolidine ring generates (regenerates) secondary amino groups and alcoholic hydroxyl groups. It is. When the isocyanate group of the isocyanate group-containing urethane prepolymer (A) reacts with moisture (humidity) in the atmosphere, it forms a urea bond and cures. At this time, carbon dioxide gas is also generated, and carbon dioxide gas is generated in the cured product. Although air bubbles are generated and defects such as deterioration of appearance, rupture of cured product, and decrease in adhesion occur, a mixture of isocyanate group-containing urethane prepolymer (A) and compound (B) having an oxazolidine ring is exposed to moisture In this case, before the moisture reacts with the isocyanate group, the oxazolidine ring of the compound (B) having an oxazolidine ring is hydrolyzed by moisture to regenerate secondary amino groups and alcoholic hydroxyl groups, and these active hydrogens are One-component moisture-curable curable composition containing these by curing without generating carbon dioxide by reacting with isocyanate groups In which due to carbon dioxide can be prevented foaming.

  In addition, when using the broad meaning aliphatic organic polyisocyanate mentioned as a preferable organic isocyanate raw material of the isocyanate group-containing urethane prepolymer (A), the curing rate is extremely delayed if the reaction is only with water. However, by using the compound (B) having an oxazolidine ring, the reaction between the secondary amino group regenerated by the reaction with water and the isocyanate group derived from the aliphatic organic polyisocyanate is more effective than the reaction with water. Since the reaction rate is high, the curing rate can be increased, and the amount of the curing accelerator (C) described later can be reduced.

  Specifically, the compound (B) having an oxazolidine ring is obtained, for example, by reacting a hydroxyl group of a compound having a hydroxyl group and an oxazolidine ring with an isocyanate group of an organic isocyanate compound or a carboxyl group of an organic carboxylic acid compound. A urethane bond-containing oxazolidine compound, an ester group-containing oxazolidine compound, or an oxazolidine silyl ether, a carbonate group-containing oxazolidine, and the like can be mentioned, and a compound having a urethane bond and an oxazolidine ring is preferable because it is easy to produce and has a low viscosity.

  Examples of the compound having a urethane bond and an oxazolidine ring include a hydroxyl group of a compound having a hydroxyl group and an oxazolidine ring and an isocyanate group of an organic isocyanate compound, and an isocyanate group / hydroxyl group equivalent ratio in the range of 0.9 to 1.2. , Preferably used in a range of 0.95 to 1.05, and obtained by reacting at a temperature of 50 to 100 ° C. in the presence or absence of an organic solvent.

  Examples of the organic isocyanate compound used for the synthesis of the urethane bond-containing oxazolidine compound include the same as those used for the synthesis of the aforementioned isocyanate group-containing urethane prepolymer (A). The aliphatic organic polyisocyanate in a broad sense is preferable, and hexamethylene diisocyanate is particularly preferable from the viewpoint of reducing the degree and improving the workability of the resulting curable composition.

  Specific examples of the compound having a hydroxyl group and an oxazolidine ring include N-hydroxyalkyloxazolidine obtained by a dehydration condensation reaction between a secondary amino group of an alkanolamine and a carbonyl group of a ketone compound or an aldehyde compound. .

  As a method for synthesizing the compound having a hydroxyl group and an oxazolidine ring, for example, the carbonyl group of the aldehyde or ketone is 1.0 equivalent or more, preferably 1.0 to 1 with respect to 1.0 equivalent of the secondary amino group of alkanolamine. .5 equivalents, more preferably 1.0 to 1.2 equivalents, and heating and refluxing in a solvent such as toluene and xylene to perform a dehydration condensation reaction while removing by-product water. It is done.

  Examples of the alkanolamine include diethanolamine, dipropanolamine, N- (2-hydroxyethyl) -N- (2-hydroxypropyl) amine and the like. Examples of the ketone compound include acetone, diethyl ketone, isopropyl ketone, methyl ethyl ketone, methyl propyl ketone, methyl isopropyl ketone, methyl butyl ketone, isobutyl ketone, methyl-t-butyl ketone, diisobutyl ketone, cyclopentanone, and cyclohexanone. Examples of the aldehyde compound include acetaldehyde, propionaldehyde, n-butyraldehyde, isobutyraldehyde, valeraldehyde, isovaleraldehyde, 2-methylbutyraldehyde, n-hexylaldehyde, 2-methylpentylaldehyde, n-octylaldehyde, 3, Aliphatic aldehyde compounds such as 5,5-trimethylhexylaldehyde, benzaldehyde, methylbenzaldehyde, trimethylbenzaldehyde, ethylbenzaldehyde, isopropylbenzaldehyde, isobutylbenzaldehyde, methoxybenzaldehyde, dimethoxybenzaldehyde, trimethoxybenzaldehyde and the like Can be mentioned.

  Among these, diethanolamine is diethanolamine as an alkanolamine in terms of ease of production of a compound having a hydroxyl group and an oxazolidine ring and excellent antifoaming property when the resulting one-component moisture-curable curable composition is cured. Of the ketone compounds or aldehyde compounds, aldehyde compounds are preferable, and isobutyraldehyde, 2-methylpentylaldehyde, and benzaldehyde are more preferable. Specific examples thereof include 2-isopropyl-3- (2-hydroxyethyl) oxazolidine, 2- (1-methylbutyl) -3- (2-hydroxyethyl) oxazolidine, 2-phenyl-3- (2-hydroxy And ethyl) oxazolidine.

  Oxazolidine silyl ether includes, for example, the above-mentioned compound having a hydroxyl group and an oxazolidine ring, trimethoxysilane, tetramethoxysilane, triethoxysilane, dimethoxydimethylsilane, vinyltrimethoxysilane, vinyltriethoxysilane, and 3-glycidoxypropyl. It can be obtained by dealcoholization reaction with alkoxysilane such as trimethoxysilane and 3-glycidoxypropyltriethoxysilane.

  Carbonate oxazolidine can be obtained, for example, 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.

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

  In addition, the compound (B) which has an oxazolidine ring has substantially no functional group which reacts with the isocyanate group of an isocyanate group containing urethane prepolymer (A) at normal temperature of 5-35 degreeC in a molecule | numerator. For example, in the synthesis of a compound having a urethane group and an oxazolidine ring, a small amount of active hydrogen may remain in the molecule due to the selection of the equivalent ratio. It means that it does not matter if it does not have to achieve.

  The amount of the compound (B) having an oxazolidine ring is such that the compound (B) having an oxazolidine ring is hydrolyzed with respect to 1.0 equivalent of the isocyanate group content in the isocyanate group-containing urethane prepolymer (A). It is preferable to use so that the active hydrogen equivalent of the secondary amino group to be regenerated is 0.3 equivalent or more, and further 0.5 to 1.0 equivalent. If it is less than 0.3 equivalent, foaming prevention is insufficient, which is not preferable.

  Next, the curing accelerator (C) used in the present invention will be described. The curing accelerator (C) accelerates the compound (B) having an oxazolidine ring to react with moisture to hydrolyze and regenerate active hydrogen, or the regenerated active hydrogen and the isocyanate It is added to promote the reaction with the isocyanate group of the group-containing urethane prepolymer (A) and improve the curing rate of the curable composition of the present invention. For example, a metal-based catalyst, an amine-based catalyst, Examples thereof include organic carboxylic acid compounds, phosphate ester compounds, p-toluenesulfonyl isocyanate, and a reaction product of p-toluenesulfonyl isocyanate and moisture.

  Examples of the metal catalyst include metal alkoxides such as tetra-n-butyl titanate, stannous octylate and tin octenoate, and metals such as zinc, tin, lead, zirconium, bismuth, cobalt, manganese and iron. Salts with organic carboxylic acid compounds similar to those described later, such as octylic acid and octenoic acid, dibutyltin bis (acetylacetonate), zirconium tetrakis (acetylacetonate), titanium tetrakis (acetylacetonate) And a salt of an organic metal such as dibutyltin dilaurate and dioctyltin dilaurate with an organic carboxylic acid compound similar to the organic carboxylic acid compound described below.

  Examples of amine catalysts include triethylenediamine, triethylamine, tri-n-butylamine, hexamethylenetetramine, 1,8-diazabicyclo [5,4,0] undecene-7 (DBU), 1,4-diazabicyclo [2,2, 2] Tertiary amines such as octane (DABCO), N-methylmorpholine, N-ethylmorpholine, and salts of these amines with organic carboxylic acids.

  Organic carboxylic acid compounds 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, etc. Examples thereof include α, β-unsaturated carboxylic acids such as aliphatic carboxylic acid, maleic acid and acrylic acid, aromatic carboxylic acids such as phthalic acid, benzoic acid and salicylic acid, and acid anhydrides thereof.

  Examples of phosphoric acid ester compounds include orthophosphoric acid ester compounds and phosphorous acid ester compounds. Examples of orthophosphoric acid ester compounds include ethyl acid phosphate, butyl acid phosphate, butoxyethyl acid phosphate, 2-ethylhexyl acid phosphate, and oleyl acid phosphate. Examples of the phosphite compound include triethyl phosphite, triphenyl phosphite, tris (nonylphenyl) phosphite, tridecyl phosphite, diphenyl mono (2-ethylhexyl) phosphite, and the like. Phosphite triester compounds such as diphenyl monodecyl phosphite, dilauryl hydrogen phosphite, dioleyl hydrogen phosphite, diphenyl hydrogen Such as phosphorous acid diester compounds such as phosphite and the like.

  The reaction product of p-toluenesulfonyl isocyanate and moisture may be obtained by reacting p-toluenesulfonyl isocyanate and moisture in advance before blending with the curable composition, or p-toluene. The sulfonyl isocyanate may be reacted by adding moisture while blended with the curable composition, or may be reacted with moisture present in the curable composition, or may be curable. After blending into the composition, it may be produced by reacting with moisture contained in an additive to be described later during storage.

  These can be used alone or in combination of two or more thereof. Among them, a metal catalyst, a phosphate ester compound, an organic carboxylic acid compound, p-toluenesulfonyl isocyanate is excellent in the effect of promoting curing. And one or more selected from the group consisting of a reaction product of p-toluenesulfonyl isocyanate and water is preferred.

  0.001-10 mass parts is preferable with respect to 100 mass parts of isocyanate group containing urethane prepolymer (A), and, as for the compounding quantity of the said hardening accelerator (C), 0.1-5 mass parts is more preferable. If the amount is less than 0.001 part by mass, the effect of accelerating the curing is small, and if it exceeds 10 parts by mass, the storage stability of the curable composition and the water resistance and heat resistance of the cured product are deteriorated.

Next, the carbonate ester compound (D) will be described.
In this invention, a carbonic acid ester compound (D) is mix | blended with the curable composition containing the isocyanate group containing urethane prepolymer (A), the compound (B) which has an oxazolidine ring, and a hardening accelerator (C). Even if the curing rate is increased, it has the effect of improving the storage stability. Moreover, since the carbonate compound (D) has good solubility of the isocyanate group-containing urethane prepolymer (A) and lowers the viscosity, it also has an effect of improving the workability of the curable composition. Examples of the carbonic acid ester compound (D) include dimethyl carbonate, diethyl carbonate, ethyl methyl carbonate, propylene carbonate and the like, and dimethyl carbonate and diethyl carbonate are preferable in terms of good storage stability and low viscosity. preferable. These may be used alone or in combination of any two or more.

  0.1-50 mass parts is preferable with respect to 100 mass parts of isocyanate group containing urethane prepolymer (A), and, as for the compounding quantity of a carbonic acid ester compound (D), 1-20 mass parts is more preferable. If it is less than 0.1 parts by mass, there is no effect of improving the storage stability, and if it exceeds 50 parts by mass, the shrinkage after curing of the curable composition is unfavorable.

Next, the additive (E) that can be further blended in the curable composition of the present invention will be described.
Additives (E) include low molecular weight plasticizers, high molecular weight diluent resins, weathering stabilizers, fillers, thixotropic agents, adhesion improvers, storage stability improvers (dehydrating agents), colorants Etc.

  Low molecular weight plasticizers and high molecular weight diluent resins are used to lower the viscosity of the resulting curable composition to improve workability and to adjust rubber elastic properties such as modulus and elongation after curing. Is.

  Specific examples of low molecular weight plasticizers include phthalates such as dioctyl phthalate, dibutyl phthalate, and butyl benzyl phthalate, dioctyl adipate, diisodecyl succinate, dibutyl sebacate, and butyl oleate. Low molecular weight compounds having a molecular weight of less than 500, such as carboxylic acid esters, alcohol esters such as pentaerythritol ester, phosphate esters such as trioctyl phosphate, tricresyl phosphate, and chlorinated paraffin. As the dilution resin, a low-viscosity resin compound having a high molecular weight having a number average molecular weight of 500 or more and having or not having a polar group in the molecule can be preferably exemplified. Examples of the polar group include an ester group, an ether group (oxyalkylene group), a urethane group, and the like and the number and the number of these groups may be included in the molecule alone or in combination. Also good. Furthermore, the dilution resin is preferably a compound that has substantially no hydroxyl group or isocyanate group in the molecule. A high molecular weight diluting resin is more preferable because it does not easily migrate (bleed) to the surface of the cured product after curing, so that the surface of the cured product is not adhered and contamination due to adhesion of dust or the like does not occur.

  Specific examples of the high molecular weight dilution resin include, for example, polar group-containing resins such as polyester resins from dicarboxylic acids and glycols, and polyoxyalkylene glycol alkyls such as polyoxyethylene glycol and polyoxypropylene glycol. Etherified derivatives, alkylesterified derivatives, saccharide-based polyhydric alcohol polyetherized resins, liquid polyoxyalkylene-based urethane resins and other polyoxyalkylene-based resins, low-viscosity (meth) acrylic acid alkyl ester-based (co) heavy Examples include coalesced resins. Examples of the resin having no polar group include hydrocarbon resins such as polyolefin resins such as polybutadiene and polyisoprene, and polyalkylene resins such as hydrogenated polybutadiene and hydrogenated polyisoprene.

  These can be used alone or in combination of two or more. Among these, the viscosity is low, the compatibility with the isocyanate group-containing urethane prepolymer (A) is good, and the workability of the resulting curable composition is good, the liquid polyoxyalkylene urethane resin, the low viscosity A (meth) acrylic acid alkyl ester (co) polymer resin is preferred.

  The number average molecular weight of the high molecular weight dilution resin is preferably 500 to 50,000, more preferably 1,000 to 30,000, particularly preferably 1,000 to 20,000, and most preferably 1,000 to 10,000. A number average molecular weight of less than 500 is not preferable because it easily migrates (bleeds) to the surface of the cured product, adheres to the surface of the cured product, and causes contamination due to adhesion of dust and the like. When the number average molecular weight exceeds 50,000, the viscosity of the dilution resin is increased, and the workability of the resulting curable composition is deteriorated.

  As the polyether-based (polyoxyalkylenated) resin of the saccharide polyhydric alcohol, ethylene oxide, propylene oxide or the like can be used with respect to the hydroxyl group of the saccharide polyhydric alcohol such as sucrose (sucrose), glucose, mannitol, sorbitol. Examples include addition (co) polymerization of alkylene oxide, alkyl etherification or alkyl esterification, and capping at the end with an alkyl group, and a resin having substantially no hydroxyl group in the molecule. As a general commercial product of the polyether resin, SPX-80 manufactured by Sanyo Chemical Industries, Ltd. can be mentioned.

  The liquid polyoxyalkylene urethane resin contains a polyoxyalkylene group and a urethane group in the molecule obtained by reacting a polyoxyalkylene alcohol and an organic isocyanate, and has substantially a hydroxyl group or an isocyanate group. High molecular weight resins are preferred. The most molecular distribution of liquid polyoxyalkylene urethane resin [ratio of weight average molecular weight (Mw) and number average molecular weight (Mn) in terms of polystyrene by gel permeation chromatography (GPC) = Mw / Mn] = 1. By making the width 6 or less, particularly preferably as narrow as 1.0 to 1.3, even if the wavy polyoxyalkylene urethane resin has a high molecular weight, the viscosity can be kept low, and the resulting curable composition Workability can be improved.

  Specifically, a polyoxyalkylene alcohol and an organic isocyanate (preferably a polyoxyalkylene monool and an organic isocyanate, or a polyoxyalkylene polyol and an organic monoisocyanate) have an isocyanate group / hydroxyl group equivalent ratio. In the range of 0.9 to 1.1 / 1.0, the reaction can be preferably carried out by preferably reacting 1/1. When the equivalent ratio is less than 0.9 / 1.0, the maximum hydroxyl group content is increased, so that it reacts with the isocyanate group of the isocyanate group-containing urethane prepolymer (A) to increase the viscosity and deteriorate the workability. If it exceeds /1.0, the content of isocyanate groups increases, which is not preferable in that the influence of the cured product on the rubber elastic properties cannot be ignored.

  The above-mentioned “substantially free of hydroxyl group or isocyanate group in the molecule” means that when synthesizing a polyether-based resin of saccharide-based polyhydric alcohol or a liquid polyoxyalkylene-based urethane resin, it depends on the molar ratio of raw materials. Although a small amount of hydroxyl group or isocyanate group may remain in the molecule, this means that there is no inconvenience even if it is assumed that no hydroxyl group or isocyanate group is contained in achieving the present invention.

  Specific examples of the polyoxyalkylene alcohol include polyoxyalkylene monools, polyoxyalkylene polyols, and mixtures thereof.

  Examples of the polyoxyalkylene monool include those obtained by ring-opening addition (co) polymerization of a cyclic ether compound to an initiator.

  Specific examples of the initiator include low-molecular alkyl monoalcohols such as methanol, ethanol, n-propanol, iso-propanol, n-butanol, iso-butanol, tert-butanol, cyclohexanol, phenol, cresol and the like. Phenols, and mixtures of two or more of these. Of these, low molecular alkyl monoalcohols having 5 or less carbon atoms such as methanol and ethanol are preferred.

  Examples of the cyclic ether compound include ethylene oxide, propylene oxide, butylene oxide, tetrahydrofuran, and a mixture of two or more thereof. Of these, propylene oxide is preferred.

  Further, the polyoxyalkylene monool is produced using the same catalyst as that used as the catalyst used for producing the polyoxyalkylene polyol used for the synthesis of the isocyanate group-containing urethane prepolymer (A). The total degree of unsaturation is preferably 0.1 meq / g or less, more preferably 0.07 meq / g or less, particularly preferably 0.04 meq / g or less, and the molecular weight distribution (Mw / Mn) is 1.6 or less, particularly 1 A narrow one of 0.0 to 1.3 is preferable in that the viscosity of the obtained liquid polyoxyalkylene urethane resin can be reduced, and the workability of the resulting curable composition is improved.

  The “system” of the polyoxyalkylene monool has the same meaning as the “system” of the polyoxyalkylene polyol used for the synthesis of the isocyanate group-containing urethane prepolymer (A) described above. .

  Examples of the polyoxyalkylene-based polyol include the same compounds as those used in the synthesis of the isocyanate group-containing urethane prepolymer.

  These can be used alone or in combination of two or more. Of these, the polyoxyalkylene monool is preferred, and the polyoxypropylene monool is particularly preferred because the viscosity of the liquid polyoxyalkylene urethane resin obtained can be lowered and the workability of the resulting curable composition is improved. Is preferred.

  As said organic isocyanate compound, the compound similar to what is used for the synthesis | combination of the above-mentioned isocyanate group containing urethane prepolymer (A) is mentioned, These can be used individually or in combination of 2 or more types. Among these, the aliphatic polyisocyanate and the aliphatic monoisocyanate in a broad sense are the point that the viscosity of the liquid polyoxyalkylene-based urethane resin obtained at a relatively low cost can be lowered and the workability of the resulting curable composition is improved. Hexamethylene diisocyanate, isophorone diisocyanate, and n-octadecyl monoisocyanate are more preferable.

  In synthesizing the liquid polyoxyalkylene urethane resin, a compound similar to the effect promoting catalyst described later can be used as a reaction catalyst. Furthermore, a well-known organic solvent can also be used.

  As the low-viscosity (meth) acrylic acid alkyl ester-based (co) polymer resin, specifically, a (meth) acrylic acid alkyl ester-based monomer and, if necessary, other ethylenically unsaturated compounds In the presence or absence of a polymerization initiator and in the presence or absence of an organic solvent at 50 to 350 ° C. by a known radical polymerization reaction such as batch or continuous polymerization (co-polymerization). ) Polymer resin, preferably obtained by high-temperature continuous polymerization reaction at 100 to 300 ° C., Tg of 0 ° C. or less, more preferably −100 to −20 ° C., viscosity at 25 ° C. of 50,000 mPa · s or less Preferably, it is a (co) polymer resin having a narrow molecular weight distribution of 100 to 10,000 mPa · s, particularly preferably 200 to 5,000 mPa · s and having a low viscosity. Or include those having no isocyanate group. If the Tg exceeds 0 ° C. and the viscosity exceeds 50,000 mPa · s, the workability of the curable composition is deteriorated.

  The (meth) acrylic acid alkyl ester (co) polymer resin may be obtained by polymerizing a (meth) acrylic acid alkyl ester monomer alone, or a (meth) acrylic acid alkyl ester monomer. Two or more kinds of the copolymer may be copolymerized, or a (meth) acrylic acid alkyl ester monomer and another ethylenically unsaturated compound may be copolymerized. Of these, (meth) acrylic acid alkyl ester copolymer resins are preferred because the resulting resin has low crystallinity and low viscosity.

  Examples of the (meth) acrylic acid alkyl ester monomer include, for example, methyl (meth) acrylate, ethyl (meth) acrylate, propyl (meth) acrylate, butyl (meth) acrylate, and (meth) acrylic acid. Isobutyl, 2-ethylhexyl (meth) acrylate, isooctyl (meth) acrylate, lauryl (meth) acrylate, tridecyl (meth) acrylate, isodecyl (meth) acrylate, stearyl (meth) acrylate, (meth) acrylic Cyclohexyl acid, cetyl (meth) acrylate, behenyl (meth) acrylate, benzyl (meth) acrylate, glycidyl (meth) acrylate, ethoxylated phenol (meth) acrylate, ethoxylated paracumylphenol (meth) acrylate, ethoxylated Nonylphenol (meth) a Mono (meth) acrylic acid esters such as relate, propoxylated nonylphenol (meth) acrylate, methoxydiethylene glycol (meth) acrylate, ethoxydiethylene glycol (meth) acrylate, tetrahydrofurfuryl (meth) acrylate, 2-phenoxy (meth) acrylate, etc. , Ethoxylated bisphenol F di (meth) acrylate, ethoxylated bisphenol A di (meth) acrylate, tripropylene glycol di (meth) acrylate, 1,6-hexanediol di (meth) acrylate, caprolactone di (meth) acrylate , Neopentyl glycol di (meth) acrylate, 1,3-butanediol di (meth) acrylate, 1,4-butanediol di (meth) acrylate, ethylene glycol Cold di (meth) acrylate, diethylene glycol di (meth) acrylate, triethylene glycol di (meth) acrylate, tetraethylene glycol di (meth) acrylate, propoxylated neopentyl glycol di (meth) acrylate, polyethylene glycol di (meth) acrylate, Poly (meth) acrylic acid ester monomers such as polypropylene glycol di (meth) acrylate, etc. can be used, and these can be used alone or in combination of two or more, but among these, a low viscosity dilution resin Is a low molecular weight mono (meth) acrylic acid alkyl ester monomer having a molecular weight of less than 500 and a molecular weight of less than 300, preferably methyl (meth) acrylate, ethyl (meth) acrylate, (meth) acrylic acid. Propyl, ( More preferred are butyl (meth) acrylate and 2-ethylhexyl (meth) acrylate.

  Examples of the ethylenically unsaturated monomer other than the (meth) acrylic acid ester monomer that can be used as needed include, for example, ethylene, propylene, isobutylene, butadiene, chloroprene, vinyl chloride, and vinylidene chloride. , Vinyl acetate, acrylonitrile, styrene, chlorostyrene, 2-methylstyrene, divinylbenzene, (meth) acrylamide, N-vinyl-pyrrolidone, etc., and these can be used alone or in combination of two or more. Of these, styrene is preferred in the same manner as described above.

  The high molecular weight dilution resin is preferably blended in an amount of 1 to 200 parts by weight, particularly 5 to 50 parts by weight, per 100 parts by weight of the isocyanate group-containing urethane prepolymer (A). If it is less than 1 part by mass, the effect of reducing the viscosity of the cured composition is lost, and if it exceeds 200 parts by mass, the durability of the cured product, such as heat resistance and water resistance, is decreased.

  The weather resistance stabilizer is used to prevent oxidation, light degradation, thermal degradation, etc. of the cured product, and to further improve not only the weather resistance but also the heat resistance, for example, an antioxidant, an ultraviolet absorption Agents and the like.

  Examples of the antioxidant include hindered amine-based and hindered phenol-based antioxidants. Examples of the hindered amine-based antioxidant include bis (2,2,6,6-tetramethyl-4-piperidyl) sebacate, Decanic acid bis (2,2,6,6-tetramethyl-1 (octyloxy) -4-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] -2,2,6,6-tetramethylpiperidine, 4-benzoyloxy-2,2,6 , 6-tetramethylpiperidine, 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-piperi (Zyl) amino] -6-chloro-1,3,5-triazine condensate. In addition, high molecular weight hindered amine antioxidants such as those manufactured by Asahi Denka Kogyo Co., Ltd. and trade names Adeka tabs LA-63P and LA-68LD are also included.

  Examples of the hindered phenol antioxidant include 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-hydroxyphenylpropioamide], benzenepropanoic acid 3, Examples include 5-bis (1,1-dimethylethyl) -4-hydroxy C7-C9 side chain alkyl ester and 2,4-dimethyl-6- (1-methylpentadecyl) phenol.

  Examples of the ultraviolet absorber include benzotriazole-based ultraviolet absorbers such as 2- (3,5-di-tert-butyl-2-hydroxyphenyl) -5-chlorobenzotriazole, 2- (4,6-diphenyl- Triazine ultraviolet absorbers such as 1,3,5-triazin-2-yl) -5-[(hexyl) oxy] -phenol, benzophenone ultraviolet absorbers such as octabenzone, 2,4-di-tert-butyl Examples thereof include benzoate ultraviolet absorbers such as phenyl-3,5-di-tert-butyl-4-hydroxybenzoate.

  These can be used alone or in combination of two or more.

  The weathering stabilizer is preferably blended in an amount of 0.01 to 30 parts by weight, particularly 0.1 to 10 parts by weight, based on 100 parts by weight of the isocyanate group-containing urethane prepolymer (A).

  Fillers, thixotropic agents, adhesion improvers, storage stability improvers (dehydrating agents), and colorants reinforce and increase physical properties, prevent sagging (slump), improve adhesion, and improve storage stability. For coloring, etc., it can be used by blending with the curable composition of the present invention.

  Fillers include mica, kaolin, zeolite, graphite, diatomaceous earth, white clay, clay, talc, slate powder, anhydrous silicic acid, quartz fine powder, aluminum powder, zinc powder, precipitated silica, synthetic silica, calcium carbonate, carbonic acid Inorganic powder fillers such as magnesium, alumina, calcium oxide, magnesium oxide, fibrous fillers such as glass fibers and carbon fibers, inorganic balloon fillers such as glass balloons, shirasu balloons, silica balloons, ceramic balloons, etc. Inorganic fillers, or fillers whose surfaces are treated with organic substances such as fatty acids, wood flour, walnut flour, rice husk flour, pulp flour, cotton chips, rubber powder, thermoplastic or thermosetting resin fine powder, Powders such as polyethylene, hollow bodies, organic balloons such as Saran microballoons Other organic fillers such as Jo fillers, also listed and flame retardant fillers such as magnesium hydroxide and aluminum hydroxide, the particle diameter 0.01~1,000μm is preferred.

  Examples of the thixotropic agent include inorganic thixotropic agents such as colloidal silica, asbestos powder and fatty acid-treated calcium carbonate, and organic thixotropic agents such as organic bentonite and fatty acid amide. Can be added.

  Examples of the adhesion improver include a coupling agent. In addition to the coupling agent, epoxy resin, phenol resin, organic polyisocyanate, and the like can be given.

  Examples of the coupling agent include various coupling agents such as silane-based, aluminum-based, and zircoaluminate-based compounds, or partial hydrolysis condensates thereof. Among these, silane-based coupling agents or partial hydrolysis-condensation products thereof. Is preferable because of its excellent adhesiveness.

  Specific examples of the silane coupling agent include methyl silicate, methyltrimethoxysilane, ethyltrimethoxysilane, butyltrimethoxysilane, octyltrimethoxysilane, dodecyltrimethoxysilane, phenyltrimethoxysilane, vinyltrimethoxy. Silane, 3-methacryloxypropyltrimethoxysilane, 3-acryloxypropyltrimethoxysilane, 3-mercaptopropyltrimethoxysilane, 3-aminopropyltrimethoxysilane, dimethyldimethoxysilane, diethyldimethoxysilane, dibutyldimethoxysilane, diphenyldimethoxy Silane, vinylmethyldimethoxysilane, 3-methacryloxypropylmethyldimethoxysilane, trimethylmethoxysilane, triethylmethoxysilane, tri Phenylmethoxysilane, N- (2-aminoethyl) -3-aminopropylmethyldimethoxysilane, N- (2-aminoethyl) -3-aminopropyltrimethoxysilane, N- (2-aminoethyl) -3-amino Low molecular weight compounds containing alkoxysilyl groups such as propylmethyldimethoxysilane, 3-glycidoxypropyltrimethoxysilane, 3-glycidoxypropylmethyldiethoxysilane, etc., having a molecular weight of 500 or less, preferably 400 or less, or these silane-based cups A compound having a molecular weight of 200 to 3,000 may be mentioned as one or two or more partially hydrolyzed condensates of the ring agent. These can be used alone or in combination of two or more.

  Examples of the storage stability improver include vinyltrimethoxysilane and calcium oxide that react with moisture present in the composition.

  Examples of the colorant include inorganic pigments such as titanium oxide and iron oxide, organic pigments such as copper phthalocyanine, and carbon black.

  These can be used alone or in admixture of two or more.

  The total amount of the filler, thixotropic agent, adhesion improver, storage stability improver, and colorant is 0 to 500 parts by mass with respect to 100 parts by mass of the isocyanate group-containing urethane prepolymer (A). In particular, the amount is preferably 5 to 300 parts by mass.

  In the curable composition of the present invention, each of the additive components can be used alone or in combination of two or more.

  In addition, the curable composition of the present invention does not foam even under severe conditions of high temperature and high humidity assuming the summer season, and the rubber elastic properties after curing are low hardness and high elongation. Can be adjusted over a wide range, and it also has excellent adhesion, water resistance, weather resistance, and other durability, so it can be used for building and civil engineering paints, waterproofing coatings, adhesives, and sealing materials. It can be used for various applications such as, but is particularly preferably used as a sealing material for construction or civil engineering.

  In addition, as the material to which the curable composition of the present invention is applied, inorganic materials such as mortar and concrete, natural stone materials such as marble, ceramic materials such as siding and tiles, polypropylene and vinyl chloride, etc. The various synthetic resin sheet-like and plate-like materials, wood-based materials such as wood and plywood, and the like are preferable because of their good adhesiveness.

  Moreover, it does not specifically limit as a manufacturing method of the curable composition of this invention, For example, the compound (B) which has an isocyanate group containing urethane prepolymer (A) component and an oxazoline ring using the reaction apparatus made from stainless steel or iron. ) Reactively synthesize the components separately. These reactions may be performed in the presence of an additive component or in the absence. Next, a method of preparing by mixing (A) component, (B) component, (C) component and (D) component in a stirring and mixing apparatus, adding an additive component as necessary, kneading, and degassing under reduced pressure. Is mentioned. Component (A) and component (B) react when exposed to moisture, causing thickening and hydrolysis. Therefore, reactive synthesis, stirring, and mixing should be carried out in a sealed state or under a nitrogen gas atmosphere so as not to contact moisture. It is preferably performed in a state where moisture is cut off. Examples of the agitation and mixing apparatus include a stainless steel and iron planetary mixer, a kneader, an agitator, a nauta mixer, a line mixer, and the like. Since the produced curable composition also reacts when exposed to moisture and thickens and hardens, it is preferably stored in a container that can block moisture, and sealed and stored. The container is not particularly limited. For example, a metal drum can made of stainless steel or iron, a pail can or bag container made of metal or synthetic resin, a laminated paper cartridge or container made of synthetic resin, etc. There are various types.

  Although the Example of this invention is shown below, it cannot be overemphasized that it is not limited to this.

[Synthesis Example 1] Synthesis of Isocyanate Group-Containing Urethane Prepolymer P-1 A polyoxypropylene diol (produced by Asahi Glass Co., Ltd., product) Name: Exenol-510, number average molecular weight: 4,000, molecular weight distribution: 1.0 to 1.2) 421.5 g and polyoxypropylene triol (Asahi Glass Co., Ltd., trade name: Exenol-5030, number average molecular weight: 5,100, molecular weight distribution: 1.0 to 1.2) 421.5 g was charged, and 156.7 g of isophorone diisocyanate (manufactured by Degussa Japan, trade name: IPDI Mw = 22.3) was added while stirring. Furthermore, after adding 0.1 g of tin octylate as a reaction catalyst, a heating (70 ° C. to 80 ° C.) reaction was performed for 4 hours with stirring to synthesize an isocyanate group-containing urethane prepolymer P-1. The reaction was terminated at an NCO concentration of 3.9% measured by titration when the NCO concentration reached the theoretical value (3.97%) or less. The reaction product was a liquid having a transparent viscosity of 4,200 mPa · s / 25 ° C. at room temperature.

Synthesis Example 2 Synthesis of Compound O-1 Having Oxazolidine Ring In a reaction vessel equipped with a stirrer, thermometer, nitrogen seal tube, reflux condenser and heating / cooling device, 435.0 g of diethanolamine (molecular weight 105) and 183 of toluene .3 g was charged and 328.3 g of isobutyraldehyde (molecular weight 72.1) was added while stirring, and reflux dehydration reaction was performed in a nitrogen gas atmosphere. Water (74.5 g) generated in the dehydration reaction was taken out of the system. After completion of the reaction, the mixture was further heated under reduced pressure (50 to 70 hPa) to remove toluene and unreacted isobutyraldehyde to obtain 2-isopropyl-3- (hydroxyethyl) oxazolidine as an intermediate reaction product.

  Next, 348.0 g of hexamethylene diisocyanate (molecular weight 168) was added to 658.9 g of the obtained 2-isopropyl-3- (hydroxyethyl) oxazolidine, and the mixture was heated at 80 ° C. for 8 hours. The time when the measured NCO content by titration was 0.0% was determined as the reaction end point, and Compound O-1 having two oxazolidine rings in the molecule through urethane bonds was obtained. The obtained reaction product was liquid at room temperature.

[Synthesis Example 3] Synthesis of Urethane Polymer Dilution Resin U-1 In a reaction vessel similar to Synthesis Example 1, while flowing nitrogen gas, polyoxypropylene diol (PML-4010 manufactured by Asahi Glass Co., Ltd., number average molecular weight 9, 930, molecular weight distribution (Mw / Mn) 1.0 to 1.1) 800 g (OH equivalent: 0.161) was charged, and n-octadecyl monoisocyanate (Millionate O, molecular weight 295, Hodogaya Chemical Co., Ltd.) 49 with stirring. .9 g (NCO equivalent: 0.169) (R value (NCO equivalent / OH equivalent) = 1.05) and 0.1 g of dibutyltin dilaurate were added, followed by heating and stirring at 70-80 ° C. for 4 hours. The reaction was terminated when the isocyanate group content became the theoretical value (0.04% by mass) or less, and a liquid urethane-based polymer dilution resin U-1 was produced.

  This liquid urethane-based polymer dilution resin U-1 has a measured isocyanate group content of 0.03% by mass by titration, a viscosity of 6,800 mPa · s / 25 ° C., and a molecular weight distribution (Mw / Mn) of 1.0 to 1. 1. It was a translucent liquid at room temperature.

[Example 1]
100 g of the isocyanate group-containing urethane prepolymer P-1 obtained in Synthesis Example 1 while flowing nitrogen gas into a kneading vessel equipped with a heating / cooling device and a nitrogen seal tube, and the compound O- having an oxazolidine ring obtained in Synthesis Example 2 19 g of 1 and 30 g of the urethane-based polymer dilution resin U-1 obtained in Synthesis Example 3 were added and dried in a dryer at 100 to 110 ° C. in advance with stirring to a water content of 0.1% by mass. 50 g of the organic fatty acid surface-treated calcium carbonate (Shiraishi Kogyo Co., Ltd., Shiruka Hana CCR) as described below and 70 g of heavy calcium carbonate were charged and mixed for 1 hour until the contents were uniform. Next, 5 g of dimethyl carbonate, 0.5 g of dibutyltin dilaurate, 0.3 g of a hindered amine light stabilizer (manufactured by Ciba Specialty Chemicals, TINUVIN765), and a hindered phenol antioxidant (manufactured by Ciba Specialty Chemicals) , IRGANOX 1010) 1 g were sequentially charged and further mixed for 1 hour until the contents were uniform. Next, after degassing under reduced pressure at 50 to 70 hPa for 30 minutes, the container was filled and sealed to prepare a paste-like one-component moisture-curable sealant composition.

[Example 2]
In Example 1, instead of using 2 g of dimethyl carbonate and not using dibutyltin dilaurate, 0.5 g of p-toluenesulfonyl isocyanate was used, and a hindered amine light stabilizer (manufactured by Ciba Specialty Chemicals, TINUVIN765) was used. A paste-like one-component moisture-curable sealant composition was prepared in the same manner except that 1.0 g was used and no hindered phenol-based antioxidant was used.

[Example 3]
In Example 1, instead of using 3 g of dimethyl carbonate and not using dibutyltin dilaurate, 0.9 g of water was added to 2 g of p-toluenesulfonyl isocyanate in advance and reacted with p-toluenesulfonyl isocyanate and water. A paste-like one-component moisture-curable sealant composition was prepared in the same manner except that 1.0 g of the reaction product was used.

[Example 4]
In Example 1, instead of using 10 g of dimethyl carbonate and not using dibutyltin dilaurate, 0.5 g of benzoic acid anhydride and 1.0 g of butyl acid phosphate were used, and no hindered amine light stabilizer was used. A paste-like one-component moisture-curable sealant composition was prepared in the same manner except that 2.0 g of a hindered phenol-based antioxidant was used.

[Comparative Example 1]
In Example 1, a paste-like one-component moisture-curing sealing was carried out in the same manner except that the compound O-1 having an oxazolidine ring obtained in Synthesis Example 2 and dimethyl carbonate were not used, but 5 g of toluene was used instead. A material composition was prepared.

[Comparative Example 2]
A paste-like one-component moisture-curable sealant composition was prepared in the same manner as in Example 1 except that 5 g of toluene was used instead of dimethyl carbonate.

  Table 1 shows the results of testing by the following test methods using the one-component moisture-curable sealant compositions obtained in Examples 1 to 4 and Comparative Examples 1 and 2.

Test Method (1) Storage Stability JIS K 6833 (1994) “General test method for adhesives”, 6.3 viscosity, the viscosity immediately after production was measured using a B-type rotational viscosity type. The viscosity value at this time is V0 (mPa · s / 23 ° C.). Separately from this, the adhesive composition filled and sealed in a container, and stored for 10 days in an accelerated condition atmosphere at 50 ° C. was left at 23 ° C. and 50% relative humidity for 1 day, Similarly, the viscosity was measured. The viscosity value at this time is V1 (mPa · s / 23 ° C.). The ratio of V1 to V0 (V1 / V0) was defined as a viscosity increase ratio, and those having a viscosity increase ratio of 2 or less were evaluated as x when the storage stability was.

(2) Tack-free Measured according to JIS A1439 (1997, revised 2002) “4.19 Tack-free test” in “Testing method for building sealing material” (measurement temperature: 23 ° C.). Tack free was evaluated as “good” when it was within 10 hours, and “x” when it was longer than 10 hours.

(3) Anti-foaming property A one-component moisture-curing sealant composition is applied in the form of a bead with a width of 20 mm, a height of 10 mm, and a length of 100 mm on the surface of a lauan plywood having a thickness of 3 mm. Cured for 14 days at relative humidity. After curing, the vicinity of the center of the width of the cured product was cut vertically in the length direction using a cutter, and the presence or absence of foaming inside the cured product was visually observed. The case where foaming was not recognized or extremely small was evaluated as “◯”, and the case where many foams were observed was evaluated as “X”.

Claims (5)

A curable composition comprising an isocyanate group-containing urethane prepolymer (A), a compound (B) having an oxazolidine ring, a curing accelerator (C), and a carbonate ester compound (D) , the carbonate ester A curable composition wherein the compound (D) is dimethyl carbonate .   The curable composition of Claim 1 whose compound (B) which has the said oxazolidine ring is a urethane bond containing oxazolidine compound.   The curing accelerator (C) is selected from the group consisting of a metal catalyst, a phosphate ester compound, an organic carboxylic acid compound, p-toluenesulfonyl isocyanate, and a reaction product of p-toluenesulfonyl isocyanate and moisture. The curable composition of Claim 1 which is a seed | species or 2 or more types. Furthermore, an additive (E) is mix | blended, The curable composition as described in any one of Claims 1-3 characterized by the above-mentioned. The curable composition according to claim 4 , wherein the additive (E) is a high molecular weight diluent resin.