JP2011068806A - Curable composition - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a curable composition containing an isocyanate group-containing urethane prepolymer and a block amine compound capable of hydrolyzing with a moisture to reproduce active hydrogen significantly excellent in foaming prevention property, which does not generate foaming in a cured product even under severer conditions such as an external wall on the south or west side of a building on a high temperature day of 25°C or higher from spring to summer. <P>SOLUTION: In the curable composition containing the isocyanate group-containing urethane prepolymer obtained by the reaction of an organic isocyanate compound and a hydroxy group-containing compound, and the block amine compound, the content of the organic isocyanate compound having a low molecular weight present in the curable composition is 0.5 mass% or less of the total curable composition. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to a curable composition containing an isocyanate group-containing urethane prepolymer having particularly excellent antifoaming properties.

Conventionally, it contains isocyanate group-containing urethane prepolymers as adhesives or coating floor materials for building exteriors such as ceramics siding and other building exterior waterproof seals, resin sheets such as vinyl chloride sheets, tiles, and wooden boards. 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.
However, when the isocyanate group-containing urethane prepolymer has a high isocyanate group concentration or increases the curing speed, it reacts with moisture (humidity) in the atmosphere and cures, and the amount of carbon dioxide generated increases. When carbon dioxide gas is abruptly generated, bubbles are generated inside the cured product, which causes problems such as deterioration of appearance, deterioration of physical properties of rubber such as elongation, and deterioration of adhesiveness.
As a means for solving this problem, the present applicant has previously proposed a technique of blending an oxazolidine compound as a latent curing agent into an isocyanate group-containing urethane prepolymer (see Patent Documents 1 to 4). And when manufacturing sealing materials for buildings using these technologies and constructing them on the outer wall joints of various buildings, it was possible to form hardened sealing joints that normally do not foam, but in sidings such as detached houses, etc. In the construction to fill the joints of the formed outer wall, there is a problem that the sealing material that is constructed foams on the high temperature of 25 degrees Celsius from spring to summer, especially on the south and west joints. However, it was found that the anti-foaming performance under more severe conditions is still insufficient, and the problem remains.

  In addition, as another technique using an oxazolidine compound, there is a technique in which a compound that does not react with an isocyanate group having a flash point of 250 ° C. or higher is added to a urethane prepolymer obtained by adding an oxazolidine compound to remove a free polyisocyanate compound. It is disclosed (see Patent Document 5). However, this technology relates to a two-pack type urethane sealing material, and the oxazolidine compound used has a hydroxyl group, and when this is added, the isocyanate group in the urethane prepolymer also reacts, so that storage is possible. It has a risk of causing problems such as an increase in viscosity and a change in physical properties of rubber after curing, which is extremely impractical.

  One-component moisture with excellent storage stability without foaming during curing, produced by mixing urethane prepolymer and inorganic filler and then mixing oxazolidine compound represented by a specific chemical formula Moisture-curing urethane that contains a curable polyurethane resin composition, a specific urethane prepolymer, a urethane compound having an oxazolidine group, and terephthalic acid fine particles having a specific particle diameter to prevent swelling of the coating film due to carbon dioxide gas A composition has been proposed, but there is still a problem that the antifoaming effect is still insufficient under severe conditions such as high temperatures and high humidity that cause remarkable foaming (see Patent Documents 6 and 7).

JP-A-2005-206722 JP 2007-63551 A JP 2007-2111040 A JP 2007-291223 A JP 2008-13695 A JP 2004-107370 A Japanese Patent Laying-Open No. 2005-226037

  In view of the above problems, the present invention provides a curable composition comprising an isocyanate group-containing urethane prepolymer and a block amine compound that can be hydrolyzed with water to regenerate active hydrogen. An object of the present invention is to provide a curable composition that is extremely excellent in antifoaming property and does not cause foaming in a cured product even under more severe conditions such as the outer wall of the south surface or west surface of a building on a high temperature day of ℃ or higher. To do.

  First of all, the present inventors made a building with a siding outer wall on the south or west side where the sun is shining on a sunny, hot day of 25 ° C or more from spring to summer. When the surface temperature of the outer wall was measured, it was found that the temperature was severe under a high temperature of 60 to 70 ° C. It was also found that the surface temperature of the outer wall becomes higher as the color of the outer wall becomes darker, such as brown. This is probably because the darker the color, the greater the infrared absorption. Therefore, even when the temperature of such an object to be constructed is severe under a high temperature of 60 to 70 ° C., the cured product does not foam when the curable composition is cured by moisture such as moisture (moisture in the atmosphere). In addition, it is necessary to further improve the anti-foaming performance of the curable composition, and as a result of intensive research, in the curable composition containing the isocyanate group-containing urethane prepolymer (A) and the block amine compound (B), The inventors have found that the above problem can be solved by limiting the amount of the low molecular weight organic isocyanate compound (C) to 0.5% by mass or less of the entire curable composition, and have completed the present invention. This is because when the low molecular weight organic isocyanate compound (C) contained in the curable composition exceeds 0.5% by mass, the organic isocyanate compound (C) is highly reactive due to its low molecular weight. Under the severe conditions as described above, the reaction between the isocyanate group and moisture such as moisture is such that the active hydrogen-containing compound regenerated by hydrolysis of the block amine compound (B) is an isocyanate of the urethane prepolymer (A). It is presumed that foaming occurs due to the generation of carbon dioxide because it occurs simultaneously with or before the reaction with the group.

That is, the present invention
(1) In the curable composition containing the isocyanate group-containing urethane prepolymer (A) obtained by reacting the organic isocyanate compound (a) and the hydroxyl group-containing compound (b), and the block amine compound (B), The curable composition is characterized in that the content of the low molecular weight organic isocyanate compound (C) present in the curable composition is 0.5% by mass or less of the entire curable composition.
And in the present invention,
(2) When the number average molecular weight of the low molecular weight organic isocyanate compound (C) is 500 or less, the adverse effect on foaming is large,
for that reason,
(3) The low molecular weight organic isocyanate compound (C) is an unreacted organic isocyanate compound (a) remaining in the isocyanate group-containing urethane prepolymer (A), and the content thereof is determined as an isocyanate group-containing urethane prepolymer. In (A), it is preferable to reduce the amount to 1.5% by mass or less.
And in said (3) term,
(4) After the unreacted organic isocyanate compound (a) is subjected to a synthesis reaction of the isocyanate group-containing urethane prepolymer (A), the isocyanate is removed without performing an operation for removing the unreacted organic isocyanate compound (a). It is preferably contained in the group-containing urethane prepolymer (A).
And to obtain the conditions of the present invention,
(5) The isocyanate group-containing urethane prepolymer (A) is an organic isocyanate compound (a) and a hydroxyl group-containing compound (b), and the reaction molar ratio of the number of moles of isocyanate groups / the number of moles of hydroxyl groups is 1.2 to 1.2. It is preferable that it is obtained by reacting at 1.8.
In the present invention,
(6) It is preferable to use a polyoxyalkylene polyol having a number average molecular weight of 2,000 or more as the hydroxyl group-containing compound (b).
Also,
(7) The organic isocyanate compound (a) is preferably an aliphatic polyisocyanate monomer,
further,
(8) The aliphatic polyisocyanate monomer is preferably isophorone diisocyanate.
In the present invention,
(9) The block amine compound (B) is preferably an oxazolidine compound.
In the present invention,
(10) Further, one or more kinds selected from the group consisting of a curing accelerator catalyst, a plasticizer, a weather resistance stabilizer, a filler, a thixotropic agent, an adhesion improver, a storage stability improver and a colorant. It is preferable to add an additive (D).
Another aspect of the present invention is as follows:
(11) The organic isocyanate compound (a) and the hydroxyl group-containing compound (b) are reacted at a reaction molar ratio of the number of moles of isocyanate group / the number of moles of hydroxyl group of 1.2 to 1.8, and the unreacted organic isocyanate compound Step (I) for synthesizing an isocyanate group-containing urethane prepolymer (A) having a content of (a) of 1.5% by mass or less, Step (II) for synthesizing a block amine compound (B), and isocyanate group-containing urethane pre The content of the low-molecular-weight organic isocyanate compound (C) is characterized by having a step (III) of blending the block amine compound (B) with the polymer (A), and the total content of the curable composition is 0.5 mass. It is a manufacturing method of the curable composition which is% or less.

  By adopting the above-described configuration, the curable composition of the present invention maintains characteristics such as storage stability, elastic properties of rubber after curing, adhesiveness, and the like, and a high temperature day of 25 ° C. or more from spring to summer. Even if it is constructed under severe conditions where the surface temperature of the construction object is 60 to 70 ° C, such as the outer wall of the south or west surface of the building, the cured product will not foam, and further improved foam prevention performance Excellent effect of having.

The curable composition of the present invention will be described in detail below.
The curable composition of the present invention is cured by blending a block amine compound (B) with an isocyanate group-containing urethane prepolymer (A) (hereinafter referred to as urethane prepolymer (A) for short), which will be described later. In preventing the foaming due to the generation of carbon dioxide gas at the time, as described above, even if it is constructed under severe conditions such as the outer wall of the south surface and the west surface of the building on a high temperature day of 25 ° C or higher from spring to summer In order to prevent foaming in the cured product, the amount (content) of the low molecular weight organic isocyanate compound (C) present in the curable composition is set to 0.5 mass of the entire curable composition. % Or less, more preferably 0.3% by mass or less. When the amount exceeds 0.5 mass, foaming starts to decrease, which is not preferable. Of course, it is most preferable that the content of the low molecular weight organic isocyanate compound (C) is 0% by mass, but this is based on the hydroxyl group during the synthesis of the isocyanate group-containing urethane prepolymer (A) as described later. It is difficult because a small amount of unreacted organic isocyanate compound (a) remains due to the reaction under the condition of excessive isocyanate groups. In the present invention, the content of the low molecular weight organic isocyanate compound (C) is a value approximately obtained from a peak area ratio measured by gel permeation chromatography (GPC) described later.

  Further, as the low molecular weight organic isocyanate compound (C), an unreacted organic isocyanate compound (a) described later remaining in the synthesis of the urethane prepolymer (A) is contained in the curable composition together with the urethane prepolymer (A). Although what is contained in this is mentioned as a typical thing, what was added later with respect to a curable composition is also included besides this.

As a method of making the low molecular weight organic isocyanate compound (C) remaining in the curable composition 0.5% by mass or less,
(A) When synthesizing the urethane prepolymer (A), the reaction molar ratio of the number of moles of isocyanate groups to the number of moles of hydroxyl groups is as small as possible, preferably 1.2 to 1.8. A method of reducing the residual amount in the urethane prepolymer (A) of the organic isocyanate compound (a) of the reaction, that is, the low molecular weight organic isocyanate compound (C) to 1.5% by mass or less as described later,
Alternatively, after synthesizing the urethane prepolymer (A) at a reaction molar ratio exceeding 1.8, an unreacted organic isocyanate compound (a), that is, a low molecular weight organic isocyanate compound (C),
(B) A method of removing by heating under reduced pressure,
(C) A method of extracting and removing with an organic solvent,
(C) A method such as adsorption to a porous material such as zeolite to remove it,
In the present invention, after the synthesis of the urethane prepolymer (A) (A), the unreacted organic isocyanate compound after the reaction is performed without removing the unreacted organic isocyanate compound (a). A method of obtaining the urethane prepolymer (A) in which the residual amount of (a) is 1.5% by mass or less is preferable because it can be produced at low cost.
In addition, as described in the above (b) to (d), after reacting at a reaction molar ratio exceeding 1.8, the method of removing the unreacted organic isocyanate compound (a) is performed by using a raw material organic isocyanate compound ( As the amount of use of a) increases, the number of steps increases and the production cost of the curable composition increases, which is not preferable.

  Examples of the low molecular weight organic isocyanate compound (C) include the same organic isocyanate compounds (a) used in the synthesis of the isocyanate group-containing urethane prepolymer (A) described later, and the number average molecular weight thereof is 500 or less. And in particular aliphatic polyisocyanate monomers are mentioned as having an adverse effect on foaming. Among the aliphatic polyisocyanate monomers, isophorone diisocyanate or hexamethylene diisocyanate, especially isophorone diisocyanate, has an adverse effect on foaming when it is present in the curable composition in the form of a monomer, thus curing its abundance. It is necessary to make it 0.5% by mass or less based on the total composition. In the present invention, the number average molecular weight and the weight average molecular weight are polystyrene-equivalent molecular weights measured by gel permeation chromatography (GPC).

  Next, the urethane prepolymer (A) component and the unreacted organic isocyanate compound (a) remaining therein will be described. The urethane prepolymer (A) is obtained by reacting the organic isocyanate compound (a) and the hydroxyl group-containing compound (b) with an isocyanate group excess condition with respect to the hydroxyl group. In the curable composition of the present invention, It functions as a curing component. In synthesizing this urethane prepolymer (A), an unreacted organic isocyanate compound (a) remains because it is reacted with hydroxyl groups under an excess of isocyanate groups. Therefore, as this unreacted organic isocyanate compound (a) blends the isocyanate group-containing urethane prepolymer (A) into the curable composition, it becomes a curable composition as a low molecular weight organic isocyanate compound (C). Will be contained. That is, since the unreacted organic isocyanate compound (a) corresponds to the low molecular weight organic isocyanate compound (C) and adversely affects foaming properties, the unreacted organic isocyanate compound is used to prevent foaming even under severe conditions. It is necessary to keep the residual amount (content) of the compound (a) as small as possible. The content of the unreacted organic isocyanate compound (a) remaining in the urethane prepolymer (A) is 0.5% by mass or less of the low molecular weight organic isocyanate compound (C) contained in the curable composition. Therefore, the amount is preferably 1.5% by mass or less, and further preferably 1.0% by mass or less, particularly preferably 0.8% by mass or less in order to obtain further excellent antifoaming performance. In addition, when the filler etc. which are mentioned later are mix | blended with a urethane prepolymer (A), the content of the low molecular weight organic isocyanate compound (C) in a curable composition may fall rather than it is diluted with a filler. This is presumably because the low-molecular-weight organic isocyanate compound (C) reacts during the production due to the water content such as the filler.

  As a method for suppressing the content of the unreacted organic isocyanate compound (a) remaining in the urethane prepolymer (A) to 1.5% by mass or less, the organic isocyanate compound (a) and the hydroxyl group-containing compound (b) are used. In the range where the molar ratio of the number of moles of isocyanate groups / the number of moles of hydroxyl groups is 1.2 to 1.8 and 1.4 to 1.7 in terms of a good balance between viscosity and excellent antifoaming performance. A method of reacting simultaneously or sequentially is preferable. When the molar ratio is less than 1.2, the viscosity of the resulting prepolymer (A) increases, the workability of the curable composition decreases, and when it exceeds 1.8, the residual prepolymer (A) remains unreacted. Since the content of the organic isocyanate compound (a) in the reaction exceeds 1.5% by mass, it is not preferable.

  Moreover, 0.1-6.0 mass% is preferable and, as for content of the isocyanate group in a urethane prepolymer (A) molecule | numerator, 0.3-3.0 mass% is preferable. When the isocyanate group content is less than 0.1% by mass, the viscosity of the urethane prepolymer (A) increases, the workability of the curable composition deteriorates, and the isocyanate group content is 6.0% by mass. When it exceeds%, even if the block amine compound (B) described later is used, generation of carbon dioxide gas due to reaction with moisture cannot be suppressed, and the cured product foams, which is not preferable.

  The urethane prepolymer (A) is suitably used as a one-component moisture-curing type because the isocyanate group in the molecule reacts with moisture such as moisture at room temperature.

  As a method for producing this urethane prepolymer (A), an organic isocyanate compound (a) and a hydroxyl group-containing compound (b) are charged into a reaction vessel made of glass or stainless steel, and in the presence of a reaction catalyst or a reaction solvent, Alternatively, there may be mentioned, for example, a method in which a urethane prepolymer (A) having a low content of unreacted organic isocyanate compound (a) is obtained by a synthesis reaction at 50 to 95 ° C. in the absence. At this time, when the isocyanate group reacts with moisture, the resulting urethane prepolymer (A) is thickened. Therefore, the reaction is preferably performed in a state where moisture is blocked, such as nitrogen gas replacement or under a nitrogen gas stream. Examples of the reaction catalyst include known urethanation reaction catalysts such as dibutyltin dilaurate, dibutyltin distearate, and zirconium stearate, and examples of the reaction solvent include the same organic solvents as described below.

  Examples of the organic isocyanate compound (a) include an organic polyisocyanate and an organic monoisocyanate optionally used for modifying the urethane prepolymer (A). Further, as the organic polyisocyanate, an isocyanate group is bonded to an aromatic carbon. And an aromatic polyisocyanate having an isocyanate group bonded to an aliphatic carbon.

Examples of aromatic polyisocyanate monomers include 4,4′-diphenylmethane diisocyanate, 2,4′-diphenylmethane diisocyanate, or mixtures thereof, such as diphenylmethane diisocyanates (MDIs); 2,4-toluene diisocyanate, 2,6 -Toluene diisocyanates (TDIs) such as toluene diisocyanate or a mixture thereof; other examples include phenylene diisocyanate, diphenyl diisocyanate, naphthalene diisocyanate, and diphenyl ether diisocyanate.
As the aliphatic polyisocyanate monomer, an araliphatic polyisocyanate having an aromatic ring in the main chain such as xylylene diisocyanate (XDI); a main chain such as hexamethylene diisocyanate, pentamethylene diisocyanate, propylene diisocyanate, butylene diisocyanate is chained. Aliphatic polyisocyanates made of hydrocarbons such as cyclohexane diisocyanate, methylene bis (cyclohexyl isocyanate), and isophorone diisocyanate (IPDI).

  Further, oligomers such as polymethylene polyphenyl polyisocyanate (also referred to as crude MDI or polymeric MDI) as well as carbodiimide-modified products, biuret-modified products, allophanate-modified products, and isocyanurate-modified products of these diisocyanates may be mentioned. Alternatively, two or more kinds can be used in combination. Among these, the monomers of the above-mentioned various polyisocyanates are preferable in that the viscosity of the urethane prepolymer (A) can be lowered, and further, the aromatic polyisocyanate is excellent in rubber elasticity and weather resistance after curing. Among them, MDIs are preferred, xylylene diisocyanate is preferred among araliphatic polyisocyanates, hexamethylene diisocyanate is preferred among aliphatic polyisocyanates, isophorone diisocyanate is preferred among alicyclic polyisocyanates, and isophorone diisocyanate is preferred. Particularly preferred.

  As the modification of the urethane prepolymer (A), the organic monoisocyanate used in some cases includes aliphatic monoisocyanates such as n-butyl monoisocyanate, n-hexyl monoisocyanate, and n-octadecyl monoisocyanate.

As the hydroxyl group-containing compound (b), in addition to the high molecular polyol, a high molecular chain polyol, a low molecular amino alcohol, or a urethane prepolymer (A) optionally used as a chain extender may be used. Examples include molecules and low molecular monools.
Examples of the polymer polyol include polyester-based polyol, polycarbonate polyol, polyoxyalkylene-based polyol, hydrocarbon-based polyol, poly (meth) acrylate-based polyol, animal and plant-based polyol, these copolyols, or a mixture of two or more thereof. Is mentioned.
The number average molecular weight of the polymer polyol is preferably 1,000 or more, more preferably 2,000 or more, still more preferably 3,000 to 30,000, and particularly preferably 3,000 to 20,000. A number average molecular weight of less than 1,000 is not preferable because rubber elastic properties such as elongation after curing of the resulting curable composition are lowered. In the present invention, “(meth) acrylate” means “acrylate and / or methacrylate”.

  Polyester polyols include succinic acid, adipic acid, sebacic acid, azelaic acid, terephthalic acid, isophthalic acid, orthophthalic acid, hexahydroterephthalic acid, hexahydroisophthalic acid, hexahydroorthophthalic acid, naphthalenedicarboxylic acid, trimellitic acid Such as polycarboxylic acids; anhydrides of these polycarboxylic acids; or one or more lower alkyl esters such as methyl esters and ethyl esters of these polycarboxylic acids, and 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, neo Pentyl glycol, 1,8-octane Low molecular polyols such as all, 1,9-nonanediol, diethylene glycol, dipropylene glycol, 1,4-cyclohexanedimethanol, ethylene oxide or propylene oxide adduct of bisphenol A, trimethylolpropane, glycerin, pentaerythritol; butylenediamine Low molecular weight polyamines such as hexamethylenediamine, xylylenediamine and isophoronediamine; polyester polyols or polyesteramides obtained by dehydration condensation reaction or dealcoholization reaction with one or more low molecular amino alcohols such as monoethanolamine or diethanolamine A polyol is mentioned.

  Further, lactone polyester polyols obtained by ring-opening polymerization of cyclic ester (lactone) monomers such as ε-caprolactone and γ-valerolactone using low molecular polyols, low molecular polyamines or low molecular amino alcohols as initiators are also included.

  As polycarbonate polyol, dehydrochlorination reaction of low molecular polyol and phosgene similar to those used for the synthesis of polyester polyol described above, or transesterification of low molecular polyol with diethylene carbonate, dimethyl carbonate, diethyl carbonate, diphenyl carbonate, etc. What is obtained by reaction is mentioned.

  As polyoxyalkylene-based polyols, the same low-molecular polyols, low-molecular polyamines, low-molecular amino alcohols, polycarboxylic acids, sorbitol, mannitol, sucrose used for the synthesis of the aforementioned polyester-based 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 Polyoxyethylene-based polyols, polyoxypropylene-based polyols, polyoxybutylene-based polyols, polyoxytetramethylene-based polyols, poly- (oxyethylene)-( Carboxy propylene) - 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. Those having a molecular weight distribution (ratio of weight average molecular weight (Mw) and number average molecular weight (Mn) = Mw / Mn) are preferably 1.6 or less, particularly preferably 1.7 meq / g or less, particularly 0.04 meq / g or less. An isocyanate group-containing urethane prepolymer (0 to 1.3 narrow) is obtained. ) Viscosity can decrease the, and the rubber elastic properties after curing of the resulting cured composition is preferable in that is good.

  In addition, for modification of the urethane prepolymer (A), polyoxypropylene 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 monools can be used.

  Examples of hydrocarbon 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 Etc.

  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 above polyoxyalkylene polyol has a low average molecular weight of less than 1,000. Or a mixture of two or more of these.

  Although the compound quoted as said hydroxyl-containing compound (b) can be used individually or in combination of 2 or more types, among these, the rubber elastic physical property and adhesiveness of the curable composition obtained are favorable. In this respect, a polymer polyol is preferable, a polyoxyalkylene-based polyol is more preferable, and a polyoxypropylene-based polyol is most preferable.

  Next, the block amine compound (B) in this invention is demonstrated. The blocked amine compound (B) is a compound obtained by dehydrating an active hydrogen bonded to a nitrogen atom of a compound having a primary and / or secondary amino group with a compound having a carbonyl group such as a ketone or an aldehyde, thereby blocking the compound. The curable composition obtained by blending this with the urethane prepolymer (A) does not react while being sealed and stored in a container, but it is opened and applied to the construction object and moisture. When contacted with moisture, the block amine compound (B) is hydrolyzed to regenerate the active hydrogen bonded to the nitrogen atom, and the regenerated active hydrogen reacts with the isocyanate group of the urethane prepolymer (A) to cause crosslinking / Since it cures, it functions as a so-called latent curing agent.

  This is because when the curable composition is cured in contact with moisture, the isocyanate group in the urethane prepolymer (A) reacts with the moisture and cures while generating carbon dioxide gas before the block amine compound (B). Hydrolyzes with water, regenerates active hydrogens of primary and / or secondary amino groups, and the rate at which these active hydrogens from amino groups react with isocyanate groups Since it is faster than the rate of reaction with the group, it does not generate carbon dioxide, but forms a urea bond and cures. Therefore, the resulting cured product is not foamed by carbon dioxide.

  Specific examples of the block amine compound (B) include a ketimine compound, an aldimine compound, an oxazolidine compound, or any mixture thereof, which is a compound having a primary and / or secondary amino group, and a ketimine compound. Is a dehydration reaction between a compound having a primary amino group and a ketone, an aldimine compound is a dehydration reaction between a compound having a primary amino group and an aldehyde, and the oxazolidine compound is a first such as monoethanolamine or diethanolamine. It can be obtained by a dehydration reaction between an amino alcohol having a secondary amino group or a secondary amino group and an aldehyde.

  Examples of the compound having a primary and / or secondary amino group include polyamines and amino alcohols, and these can be used alone or in admixture of two or more. Examples of the polyamine include ethylenediamine, phenylenediamine, diethylenetriamine, triethylenetetraamine, methylaminopropylamine, 3,3′-diaminodipropylamine, and the like. Examples of amino alcohols include monoethanolamine and diethanolamine.

  Examples of the ketones include methyl ethyl ketone, methyl isopropyl ketone, methyl isobutyl ketone, 2-pentanone, 3-pentanone, 2-hexanone, 4-methyl-2-pentanone, 2-heptanone, 4-heptanone, diisopropyl ketone, diisobutyl ketone, and the like. Aliphatic ketones; aromatic ketones such as propiophenone and benzophenone; cyclic ketones such as cyclopentanone, cyclohexane and methylcyclohexane; 6-dicarbonyl compounds such as ethyl acetoacetate, or any mixture thereof. Can be mentioned.

  Examples of the aldehydes include propionaldehyde, n-butyraldehyde, isobutyraldehyde, n-pentylaldehyde, 2-methylbutyraldehyde, n-hexyl alkyd, 2-methylpentanal, n-heptyl alkyd, n-octyl aldehyde. Hydride, benzaldehyde, cuminaldehyde, or any mixture thereof.

  Of the compounds mentioned as the block amine compound (B), an oxazolidine compound is preferred because it is excellent in storage stability and antifoaming performance of the resulting curable composition, and moreover, by dehydration reaction between diethanolamine and isobutyraldehyde. The resulting oxazolidine compound is preferred. Furthermore, the hydroxyl group remaining in the molecule of the compound having an oxazolidine group obtained by dehydration reaction of diethanolamine and aldehydes is the same as the isocyanate group of the organic polyisocyanate mentioned in the synthesis of the urethane prepolymer (A). Particularly preferred are urethane bond-containing oxazolidine compounds obtained by urethanization with benzene. In this case, the organic polyisocyanate to be used is preferably an aliphatic polyisocyanate, particularly hexamethylene diisocyanate, in view of the low viscosity of the resulting latent curing agent.

  Next, the additive (D) that is preferably added to the curable composition of the present invention will be described. The additive (D) is blended into the curable composition and used for improving various performances such as acceleration of curing and improvement of adhesiveness, specifically, a curing accelerating catalyst, a plasticizer, Examples include weathering stabilizers, fillers, thixotropic agents, adhesion improvers, storage stability improvers (dehydrating agents), colorants, etc., selected from these groups depending on the use of the curable composition. These can be used alone or in combination of two or more.

  The curing accelerator includes a hydrolysis reaction rate at which the block amine compound (B) hydrolyzes with moisture to generate active hydrogen, and the generated active hydrogen reacts with the isocyanate group of the urethane prepolymer (A) to cure. In order to increase the curing speed of the curable composition of the present invention.

Examples of the curing accelerating catalyst include tin octylate, tin naphthenate, zinc octylate, bismuth octylate, zirconium octylate and the like, metals such as bismuth, zinc, zirconium, tin, lead, octyl acid, neodecanoic acid, stearin. Salts with organic acids such as acids and naphthenic acids; organic tins such as dibutyltin dilaurate, dibutyltin diacetate, dibutyltin dineodecanate, dibutyltin distearate, dibutyltin dioctoate, dioctyltin dilaurate, dioctyltin distearate, and dioctyltin diacetate Examples include salts with organic acids.
The amount of the curing accelerating catalyst used is preferably 5 parts by mass or less, particularly 0.1 to 5 parts by mass, based on 100 parts by mass of the urethane prepolymer (A). If the amount used exceeds 5 parts by mass, the storage stability decreases, such being undesirable.

Plasticizers are used to reduce the viscosity of curable compositions and improve workability, and to adjust the rubber elastic properties of cured products. Phthalate esters such as dioctyl phthalate, dibutyl phthalate, and butyl benzyl phthalate Low molecular weight plasticizers such as aliphatic carboxylic acid esters such as dioctyl adipate, diisodecyl succinate, dibutyl sebacate, butyl oleate, etc .; similar to those used for the synthesis of the above urethane group-containing urethane prepolymers A compound obtained by etherification or esterification of a polyether polyol or polyether monool; a high molecular weight plasticizer having a molecular weight of 1,000 or more which does not react with isocyanate groups such as poly-α-methylstyrene and polystyrenes such as polystyrene; It is done. These can be used alone or in combination of two or more.
The plasticizer is preferably blended in an amount of 1 to 200 parts by mass and further 2 to 50 parts by mass with respect to 100 parts by mass of the urethane prepolymer (A).

  Weathering stabilizers are used for the purpose of further improving heat resistance as well as weather resistance by preventing oxidation, photodegradation, and thermal degradation of cured products, hindered amine light stabilizers, hindered phenolic antioxidants, UV absorption Examples of hindered amine light stabilizers include bis (2,2,6,6-tetramethyl-4-piperidyl) sebacate and bis (2,2,6,6-tetramethyl-1) decanedioate. (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) sebake 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 and other low molecular weight compounds having a molecular weight of less than 1,000; Dimethyl 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) Mino}], N, N′-bis (3-aminopropyl) ethylenediamine-2,4-bis [N-butyl-N- (1,2,2,6,6-pentamethyl-4-piperidyl) amino]- In addition to 6-chloro-1,3,5-triazine condensate and the like, high molecular weight compounds having a molecular weight of 1,000 or more, such as trade names ADK STAB LA-63P and LA-68LD manufactured by ADEKA, and the like can be mentioned.

  As the hindered phenol-based 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-bisbenzenepropanoate (1,1-dimethylethyl) -4-hydroxy C7-C9 side chain alkyl ester, 2,4-dimethyl-6- (1-methylpentadecyl) phenol and the like.

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-1, 3,5-triazin-2-yl) -5-[(hexyl) oxy] -phenol and other triazine ultraviolet absorbers; benzophenone ultraviolet absorbers such as octabenzone; 2,4-di-tert-butylphenyl-3 Benzoate-based ultraviolet absorbers such as 5-di-tert-butyl-4-hydroxybenzoate.

Although these can be used individually or in combination of 2 or more types, a hindered amine type light stabilizer and / or a hindered phenol type antioxidant are preferable at the point which the effect of a weather resistance improvement is high among these. It is preferable that the weathering stabilizer is blended in an amount of 0.01 to 30 parts by mass, and further 0.1 to 10 parts by mass with respect to 100 parts by mass of the urethane prepolymer (A).

  The filler is used for the purpose of increasing the amount of the curable composition and reinforcing the physical properties of the cured product.Mica, kaolin, zeolite, graphite, diatomaceous earth, white clay, clay, talc, slate powder, silicic anhydride, quartz fine powder, aluminum Powder, zinc powder, synthetic silica such as precipitated silica, inorganic powder filler such as calcium carbonate, magnesium carbonate, alumina, calcium oxide, magnesium oxide; fiber filler such as glass fiber, carbon fiber; glass balloon, shirasu Inorganic fillers such as inorganic balloon fillers such as balloons, silica balloons and ceramic balloons; or fillers whose surfaces are treated with organic substances such as fatty acids; wood powder, walnut shell powder, rice husk powder, pulp powder Cotton chips, rubber powder, thermoplastic or thermosetting resin fine powder, polyethylene powder, etc. In addition to organic fillers such as organic balloon-like fillers such as body and saran microballoons, flame retardant imparting fillers such as magnesium hydroxide and aluminum hydroxide, etc. are also included, and the particle size is 0.01 to 1 1,000 μm is preferred.

  The thixotropic agent is used for the purpose of preventing sagging (slump) of the curable composition, and imparts inorganic thixotropic agents such as fine powder silica and fatty acid-treated calcium carbonate; organic thixotropic properties such as organic bentonite and fatty acid amide. These can be used singly or in combination of two or more, but among these, even if a highly polar compound such as the block amine compound (B) is used, stable thixotropy can be imparted without causing dripping. In this respect, fatty acid-treated calcium carbonate is preferable.

  Adhesion improvers are used for the purpose of improving the adhesiveness of cured products, and can include various coupling agents such as silane-based, aluminum-based and zircoaluminate-based compounds or partially hydrolyzed condensates thereof. A silane coupling agent or a partially hydrolyzed condensate thereof is preferable because of its excellent adhesiveness.

  As this 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-amino) Ethyl) -3-aminopropylmethyldiethoxysilane, 3-glycidoxypropyltrimethoxysilane, 3-glycidoxypropylmethyldiethoxysilane and other alkoxysilyl group-containing molecular weights of 500 or less, preferably 400 or less. Molecular compound or this Examples of the silane coupling agent include one or two or more partially hydrolyzed condensates of a molecular weight of 200 to 3,000. These can be used alone or in combination of two or more.

  A storage stability improver (dehydrating agent) is used for the purpose of improving the storage stability of a curable composition, and reacts with moisture present in the curable composition to act as a dehydrating agent. , Calcium oxide, p-toluenesulfonyl isocyanate and the like. In addition, although p-toluenesulfonyl isocyanate corresponds to the low molecular weight organic isocyanate compound (C) as it is, it reacts with moisture present in the composition during the production or storage of the curable composition, Most of them are p-toluenesulfonylamide and do not adversely affect foaming, so they are not included in the low molecular weight organic isocyanate compound (C) in the present invention.

  The colorant is used for the purpose of coloring the curable composition and imparting design properties to the cured product, and includes 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 blending amount of the filler, thixotropic agent, adhesion improver, storage stability improver, and colorant is 0 to 500 parts by mass, particularly 5 to 100 parts by mass of the urethane prepolymer (A). It is preferable that it is 300 mass parts.

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

  An organic solvent can also be used for the purpose of reducing the viscosity of the curable composition of the present invention and improving the workability of extrusion and coating. Examples of organic solvents include ester solvents such as ethyl acetate; ketone solvents such as methyl ethyl ketone; aliphatic solvents such as n-hexane; naphthene solvents such as methylcyclohexane, ethylcyclohexane, dimethylcyclohexane, and mixtures thereof; The solvent which does not react with the isocyanate group of urethane prepolymer (A), such as aromatic solvents, such as xylene, is mentioned. Examples of suitable commercially available naphthenic solvents include Exon Mobil's Exol series D30, D40, D80, Shell Japan's Shellsol series D40, D60, D70, and the like. These can be used alone or in combination of two or more. Of these, naphthenic solvents are preferred in that they are less toxic and have less adverse effects on the environment. However, among naphthenic solvents, cyclohexane is preferably not used because its boiling point is too low and there is a high risk of ignition. In addition, in order to suppress the emission of volatile substances and have no adverse effect on the environment, the amount of the organic solvent used is preferably as small as possible, and is 10% by mass or less, further 5% by mass of the entire curable composition. It is preferable to make it below, and it is most preferable not to use 0 mass%.

  The curable composition of the present invention is particularly preferable to be used as a one-component moisture-curing type because there is no need to mix the main agent and the curing agent, and there is no occurrence of curing failure due to a mixing error and excellent workability. However, it can also be used as a two-component curable type having a curable composition as a main component and an active hydrogen-containing compound such as amine or polyol as a curing agent.

  Further, 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 property after curing is low hardness and high elongation to high hardness and low 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, the materials to which the curable composition of the present invention is applied include cement-based materials such as mortar and concrete; natural stone materials such as marble; ceramic materials such as siding and tiles; various materials such as polypropylene and vinyl chloride A sheet-like or plate-like material made of a synthetic resin; a wood-based material such as wood or plywood is preferable because of its good adhesion. Among these, it is particularly preferable that the outer wall joint formed by siding is an object of construction because the effects of the present invention can be exhibited to the maximum.

Although it does not specifically limit as a manufacturing method of the curable composition of this invention, First, using a stainless steel or glass-made reaction apparatus, as above-mentioned, an organic isocyanate compound (a) and a hydroxyl-containing compound (b) are made. Isocyanate group-containing urethane in which the reaction molar ratio of the number of moles of isocyanate groups / the number of moles of hydroxyl groups is 1.2 to 1.8, and the content of the unreacted organic isocyanate compound (a) is 1.5% by mass or less. Step (I) for synthesizing the prepolymer (A) is carried out. Then, step (II) for synthesizing the block amine compound (B) is carried out as described above separately from step (I). These reactions may be performed in the presence of the additive (D) or in the absence. Next, as a preferred method, a method in which the components (A) and (B) are charged into a stirring and mixing apparatus, and more preferably the additive component (D) is added and kneaded and then degassed under reduced pressure at 30 to 100 hPa. It is done.
Hereinafter, the present invention will be described in more detail with reference to examples and the like using a one-component moisture-curing sealing material as an example of the curable composition, but the present invention is not limited thereto.

Synthesis Example 1 Synthesis of Urethane Prepolymer Solution P-1 A polyoxypropylene diol (produced by Asahi Glass Co., Ltd., Exenol-2020, number) while flowing nitrogen gas into a reactor equipped with a stirrer, thermometer, nitrogen seal tube and heating / cooling device. 1,990 g of average molecular weight 1,990) and 331 g of polyoxypropylene triol (Asahi Glass Co., Ltd., Exenol-5030, number average molecular weight 5,100) and naphthenic solvent (Exxon Mobil Co., Exol D40) as a reaction solvent While stirring, 86 g of isophorone diisocyanate (Evonik Degussa Japan, VESTANAT IPDI, molecular weight 222) was charged while stirring, and 0.8 g of dibutyltin dilaurate (Nitto Kasei, Neostan U-100) was added as a reaction catalyst. At 80 ° C., after which the isocyanate group content by titration was stirred for 2 hours until less than the theoretical value (1.34 wt%), to synthesize a urethane prepolymer solution P-1 and the reaction was terminated by cooling. The reaction molar ratio (number of moles of isocyanate group / number of moles of hydroxyl group) at this time is 1.4.
The obtained urethane prepolymer solution P-1 had an isocyanate group content of 1.28 mass% by titration, a viscosity of 28,600 mPa · s at 25 ° C. by a B-type rotational viscometer, and a urethane prepolymer resin content of 97 mass. % Clear transparent liquid at room temperature.

Synthesis Example 2 Synthesis of Urethane Prepolymer Solution P-2 In Synthesis Example 1, 365 g of isophorone diisocyanate (IPDI) was used and stirred for 2 hours until the isocyanate group content by titration was less than the theoretical value (1.66% by mass). A urethane prepolymer solution P-2 was synthesized in the same manner except that. The reaction molar ratio at this time is 1.5.
The obtained urethane prepolymer solution P-2 was viscous at room temperature with an isocyanate group content of 1.63% by mass, a viscosity at 25 ° C. of 17,000 mPa · s, and a urethane prepolymer resin content of 97% by mass. It was a clear liquid.

Synthesis Example 3 Synthesis of Urethane Prepolymer Solution P-3 In Synthesis Example 1, 390 g of isophorone diisocyanate (IPDI) was used and stirred for 2 hours until the isocyanate group content by titration was less than the theoretical value (1.98% by mass). A urethane prepolymer solution P-3 was synthesized in the same manner except that. The reaction molar ratio at this time is 1.6.
The obtained urethane prepolymer solution P-3 was viscous at room temperature with an isocyanate group content of 1.94 mass% by titration, a viscosity of 10,800 mPa · s at 25 ° C., and a urethane prepolymer resin content of 97 mass%. It was a clear liquid.

Synthesis Example 4 Synthesis of Urethane Prepolymer Solution P-4 In Synthesis Example 1, 330 g of xylylene diisocyanate (XDI) (manufactured by Mitsui Chemicals, Takenate 500, molecular weight 188) was used instead of IPDI. A urethane prepolymer solution P-4 was synthesized in the same manner except that the amount was stirred for 2 hours until the amount became less than the theoretical value (2.02% by mass). The reaction molar ratio at this time is 1.6.
The obtained urethane prepolymer solution P-4 was viscous at room temperature with an isocyanate group content of 1.98 mass% by titration, a viscosity of 15,900 mPa · s at 25 ° C., and a urethane prepolymer resin content of 97 mass%. It was a clear liquid.

Synthesis Example 5 Synthesis of Urethane Prepolymer Solution P-5 Polyoxypropylenediol (Asahi Glass Co., Ltd., Exenol-3021, number average molecular weight 3,270) was added to the same reaction vessel as in Synthesis Example 1 while flowing nitrogen gas. , 635 g and polyoxypropylene triol (Mitsui Chemicals, Actol MN-4000, number average molecular weight 3, 970) 272 g and 68 g of Exol D40 as a reaction solvent were stirred and stirred with isophorone diisocyanate (Evonik Degussa Japan, 227 g of VESTANAT IPDI, molecular weight 222) was added, and 0.6 g of dibutyltin dilaurate (Nitto Kasei Co., Ltd., Neostan U-100) was added as a reaction catalyst, and the content of isocyanate groups by titration at 70 to 80 ° C. was theoretical (1 .60 mass%) or less After stirring for 2 hours until, to synthesize a urethane prepolymer solution P-5 and reaction was terminated by cooling. The reaction molar ratio (number of moles of isocyanate group / number of moles of hydroxyl group) at this time is 1.7.
The obtained urethane prepolymer solution P-5 has an isocyanate group content of 1.55% by mass by titration, a viscosity of 12,000 mPa · s at 25 ° C. by a B-type rotational viscometer, and a content of 97% by mass of the urethane prepolymer resin. % Clear transparent liquid at room temperature.

Synthesis Example 6 Synthesis of Urethane Prepolymer Solution P-6 In Synthesis Example 1, 439 g of isophorone diisocyanate (IPDI) was used and stirred for 2 hours until the isocyanate group content by titration was less than the theoretical value (2.60% by mass). A urethane prepolymer solution P-6 was synthesized in the same manner except that. In this case, the reaction molar ratio is 1.8.
The obtained urethane prepolymer solution P-6 was viscous at room temperature with an isocyanate group content of 2.55 mass% by titration, a viscosity of 5,400 mPa · s at 25 ° C., and a urethane prepolymer resin content of 97 mass%. It was a clear liquid.

Synthesis Example 7 Synthesis of Urethane Prepolymer Solution P-7 In Synthesis Example 5, 204 g of xylylene diisocyanate (XDI) was used instead of IPDI, and the isocyanate group content by titration was less than the theoretical value (1.86% by mass). A urethane prepolymer solution P-7 was synthesized in the same manner except that the mixture was stirred for 2 hours until. In this case, the reaction molar ratio is 1.8.
The obtained urethane prepolymer solution P-7 was viscous at room temperature with an isocyanate group content of 1.82% by mass, a viscosity at 25 ° C. of 8,600 mPa · s, and a urethane prepolymer resin content of 97% by mass. It was a clear liquid.

Comparative Synthesis Example 1 Synthesis of Urethane Prepolymer Solution Comparison P-1 In Synthesis Example 1, except that 463 g of IPDI was used and stirring was performed for 2 hours until the isocyanate group content by titration was less than the theoretical value (2.89% by mass). In the same manner, urethane prepolymer solution comparison P-1 was synthesized. The reaction molar ratio at this time is 1.9.
The obtained urethane prepolymer solution comparison P-1 has a viscosity of 2.85 mass% by titration, a viscosity of 4,500 mPa · s at 25 ° C., and a urethane prepolymer resin content of 97 mass% at room temperature. It was a thick transparent liquid.

Comparative Synthesis Example 2 Synthesis of Urethane Prepolymer Solution Comparison P-2 In Synthesis Example 5, except that 254 g of IPDI was used and stirring was performed for 2 hours until the isocyanate group content by titration was less than the theoretical value (2.04% by mass). In the same manner, urethane prepolymer solution comparison P-2 was synthesized. The reaction molar ratio at this time is 1.9.
The obtained urethane prepolymer solution comparison P-1 has an isocyanate group content of 2.01 mass% by titration, a viscosity of 5,100 mPa · s at 25 ° C., and a urethane prepolymer resin content of 97 mass%. It was a thick transparent liquid.

Comparative Synthesis Example 3 Synthesis of Urethane Prepolymer Solution Comparison P-3 In Synthesis Example 4, 413 g of XDI was used, and the mixture was stirred for 2 hours until the isocyanate group content by titration was less than the theoretical value (3.27% by mass). In the same manner, urethane prepolymer solution comparison P-3 was synthesized. The reaction molar ratio at this time is 2.0.
The obtained urethane prepolymer solution comparison P-3 had an isocyanate group content of 3.22 mass% by titration, a viscosity of 3,800 mPa · s at 25 ° C., and a urethane prepolymer resin content of 97 mass%. It was a thick transparent liquid.

Synthesis Example 8 Synthesis of Urethane Bond-Containing Oxazolidine Compound O-1 435 g of diethanolamine (molecular weight 105), 183 g of toluene, and isobutyl while flowing nitrogen gas into a reactor equipped with a stirrer, thermometer, nitrogen seal tube and heating / cooling device 328 g of aldehyde (molecular weight 72.1) was charged, heated with stirring, and reflux dehydration reaction was continued at 110 to 150 ° C., and by-product water (74.5 g) 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 N-hydroxydiethyl-2-isopropyloxazolidine as an intermediate reaction product. Next, 348 g of hexamethylene diisocyanate (molecular weight 168) was further added to 659 g of the obtained N-hydroxydiethyl-2-isopropyloxazolidine, heated at 80 ° C. for 8 hours, and the NCO content actually measured by titration was reduced to 0.0 mass%. At this point, the reaction was terminated, and a urethane bond-containing oxazolidine compound O-1 having two oxazolidine rings in the molecule was obtained. The obtained urethane bond-containing oxazolidine compound O-1 was liquid at room temperature.

Example 1
1,000 g of urethane prepolymer solution P-1 obtained in Synthesis Example 1, 250 g of dioctyl phthalate (DOP), and a naphthenic solvent (flowing) while flowing nitrogen gas into a kneading vessel equipped with a heating and cooling device and a nitrogen seal tube 60 g of Exxon Mobil Exol D40), 300 g of heavy calcium carbonate with a water content of 0.05% by mass or less and the surface of the fatty acid were previously dried in a drier at 100 to 110 ° C. while stirring. 700 g of treated calcium carbonate (manufactured by Shiraishi Kogyo Co., Ltd., Shiruka Hana CCR) was sequentially charged, and stirred and kneaded at 30 to 50 ° C. until the contents became uniform. Next, 3 g of p-toluenesulfonyl isocyanate, 37 g of urethane bond-containing oxazolidine compound O-1 obtained in Synthesis Example 8, hindered amine light stabilizer (Ciba Japan, CHIMASSORB 944LD, molecular weight 2000 to 3100, 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}]))) and hindered phenol antioxidant (Ciba Japan, IRGANOX 1010, molecular weight 1178, pentaerythritol-tetrakis [3- (3,5-di-tert-butyl-4-hydroxyphenyl) propione 10 g) was stirred and kneaded until it became more uniform. Subsequently, it was degassed under reduced pressure at 50 to 100 hPa, filled and sealed in a paper cartridge-like container, and a paste-like one-component moisture-curable urethane-based sealing material S-1 was produced.

Examples 2-7
In Example 1, instead of the urethane prepolymer solution P-1, 1,000 g of the urethane prepolymer solution P-2 obtained in Synthesis Example 2 and 47 g of the urethane bond-containing oxazolidine compound O-1 obtained in Synthesis Example 8 were used. 1,000 g of urethane prepolymer solution P-3 obtained in Synthesis Example 3 and 56 g of urethane bond-containing oxazolidine compound O-1 and 1,000 g of urethane prepolymer solution P-4 obtained in Synthesis Example 4 Containing oxazolidine compound O-1 57 g, urethane prepolymer solution P-5 obtained in Synthesis Example 5 1,000 g, urethane bond-containing oxazolidine compound O-1 45 g, urethane prepolymer solution P- obtained Synthesis Example 6 1,000 g of urethane 6 and 74 g of urethane bond-containing oxazolidine compound O-1, urethane prepolymer obtained in Synthesis Example 7 In the same manner, except that 1,000 g of solution P-7 and 53 g of urethane bond-containing oxazolidine compound O-1 were used, paste-like one-component moisture-curable urethane-based sealing materials S-2 to S-7 were produced. did.

Comparative Examples 1-3
In Example 1, instead of the urethane prepolymer solution P-1, 1,000 g of the urethane prepolymer solution comparison P-1 obtained in Comparative Synthesis Example 1 and the urethane bond-containing oxazolidine compound O-1 obtained in Synthesis Example 8 were used. 82 g, 1,000 g of urethane prepolymer solution comparison P-2 obtained in Comparative Synthesis Example 2, 58 g of urethane bond-containing oxazolidine compound O-1, and urethane prepolymer solution comparison P-3 obtained in Comparative Synthesis Example 3 In the same manner except that 1,000 g and 93 g of urethane bond-containing oxazolidine compound O-1 were used, paste-like one-component moisture-curing urethane-based sealing material comparison S-1 to comparison S-3 were produced.

Using the urethane prepolymer solutions obtained in Synthesis Examples 1 to 7 and Comparative Synthesis Examples 1 to 3, the following “A. Measurement of Unreacted Organic Diisocyanate (IPDI Monomer or XDI Monomer) Content in Urethane Prepolymer Resin Component” The value of the content obtained by “Method” is shown in Tables 1 to 3 as the test result of the urethane prepolymer solution together with the viscosity of the urethane prepolymer solution and the isocyanate group content.
And using the 1 liquid moisture hardening type sealing material obtained in Examples 1-7 and Comparative Examples 1-3, the result tested by the following "B. Test method of sealing material" with a compounding composition is shown in Tables 4-6. To

A. Method for Measuring Content of Unreacted Organic Diisocyanate (IPDI Monomer or XDI Monomer) in Urethane Prepolymer Resin Component Using the obtained urethane prepolymer solution as a sample, 0.2 g of this sample was sampled into 10 ml of tetrahydrofuran (THF). It melt | dissolved and it was set as the sample solution. The sample solution was subjected to gel permeation chromatography (GPC) under the following conditions. From the peak area of the urethane prepolymer and the peak area of unreacted organic diisocyanate (IPDI monomer or XDI monomer) in the obtained chromatogram, The content a (% by mass) of the unreacted organic diisocyanate in the urethane prepolymer resin component was determined by the following calculation formula (1).

計算式（１）において、
ａ：ウレタンプレポリマー樹脂分中の未反応有機ジイソシアネート（ＩＰＤＩモノマーまたはＸＤＩモノマー）の含有量（質量％）
Ｓ１：未反応有機ジイソシアネートモノマーのピーク面積
Ｓ２：ウレタンプレポリマーのピーク面積の合計 GPC conditions Equipment: HLC-8220 GPC manufactured by Tosoh Corporation
Column: TSKgelSuperHM-M and Super2000
Eluent: THF
Detector: RI

In the calculation formula (1),
a: Content (% by mass) of unreacted organic diisocyanate (IPDI monomer or XDI monomer) in the urethane prepolymer resin component
S1: Peak area of unreacted organic diisocyanate monomer S2: Total peak area of urethane prepolymer

B. Sealing material test method 1) Slump JIS A 1439 (2004) “Building sealing material test method” “5.1 Slump test”, using a grooved container with a width of 10 mm, slump (vertical) at 23 ° C. It was measured.

計算式（２）において、
ｂ：シーリング材中の未反応有機ジイソシアネート（ＩＰＤＩモノマーまたはＸＤＩモノマー）の含有量（質量％）
Ｓ１：未反応有機ジイソシアネートモノマーのピーク面積
Ｓ２：ウレタンプレポリマーのピーク面積の合計
Ｍ：シーリング材の総仕込み量（ｇ）
Ｈ：ウレタンプレポリマー溶液の仕込み量（ｇ）（表４〜６においては１，０００ｇ）
ｄ：ウレタンプレポリマー溶液中の樹脂分含有量（質量％）（表４〜６においては９７質量％＝０．９７） 2) Measurement of the content of unreacted organic diisocyanate (IPDI monomer or XDI monomer) in the sealing material Using the obtained one-component moisture-curing sealing material as a sample, 0.2 g of this sample was sampled and 10 ml of tetrahydrofuran (THF). Then, the supernatant obtained by centrifuging was used as a sample solution. The sample solution was subjected to GPC under the same conditions as the measurement of the content of unreacted organic diisocyanate in the urethane prepolymer, and the peak area of the urethane prepolymer in the obtained chromatogram and the unreacted organic diisocyanate (IPDI monomer or XDI From the peak area of the monomer, the content b (mass%) of the unreacted organic diisocyanate in the sealing material was determined by the following calculation formula (2).

In the calculation formula (2),
b: Content (mass%) of unreacted organic diisocyanate (IPDI monomer or XDI monomer) in the sealing material
S1: Peak area of unreacted organic diisocyanate monomer S2: Total peak area of urethane prepolymer M: Total amount of sealant charged (g)
H: Charge amount of urethane prepolymer solution (g) (1,000 g in Tables 4 to 6)
d: Resin content (% by mass) in the urethane prepolymer solution (97% by mass = 0.97 in Tables 4 to 6)

3) Anti-foaming property On the surface of a 3mm thick lauan plywood, a 14mm square x 100mm long lauan square bar is placed in parallel with a 20mm width, bonded, 20mm wide x 14mm deep x 100mm long This joint was filled with a sealing material, and an excess sealing material was scraped off with a spatula to make a flat surface, which was used as a test specimen.
This specimen was cured and cured for 3 days in a constant temperature and humidity chamber at 70 ° C. and 80% relative humidity, and then taken out. The cured sealing material was cut out with a cutter, and the vicinity of the center was cut in the length direction. The presence or absence of foaming was visually observed. A case where foaming or cracking was not recognized or very little was evaluated as ◯, and a case where many foaming was observed was evaluated as ×.

Claims (11)

In the curable composition containing the isocyanate group-containing urethane prepolymer (A) obtained by reacting the organic isocyanate compound (a) and the hydroxyl group-containing compound (b), and the block amine compound (B),
A curable composition, wherein the content of the low molecular weight organic isocyanate compound (C) present in the curable composition is 0.5% by mass or less of the entire curable composition.   The curable composition of Claim 1 whose number average molecular weights of the said low molecular weight organic isocyanate compound (C) are 500 or less.   The low-molecular weight organic isocyanate compound (C) is an unreacted organic isocyanate compound (a) remaining in an amount of 1.5% by mass or less in the isocyanate group-containing urethane prepolymer (A). Or the curable composition of 2.   The said unreacted organic isocyanate compound (a) is the isocyanate group-containing urethane without performing an operation of removing the unreacted organic isocyanate compound (a) after the synthesis reaction of the isocyanate group-containing urethane prepolymer (A). The curable composition according to claim 3, which is contained in the prepolymer (A).   When the isocyanate group-containing urethane prepolymer (A) is an organic isocyanate compound (a) and a hydroxyl group-containing compound (b), the reaction molar ratio of the number of moles of isocyanate groups to the number of moles of hydroxyl groups is 1.2 to 1.8. The curable composition as described in any one of Claims 1-4 which is a thing obtained by reacting by.   The curable composition according to any one of claims 1 to 5, wherein the hydroxyl group-containing compound (b) is a polyoxyalkylene polyol having a number average molecular weight of 2,000 or more.   The curable composition according to any one of claims 1 to 6, wherein the organic isocyanate compound (a) is an aliphatic polyisocyanate monomer.   The curable composition according to claim 7, wherein the aliphatic polyisocyanate monomer is isophorone diisocyanate.   The curable composition according to any one of claims 1 to 8, wherein the block amine compound (B) is an oxazolidine compound.   Further, one or more additives selected from the group consisting of curing accelerators, plasticizers, weathering stabilizers, fillers, thixotropic agents, adhesion improvers, storage stability improvers and colorants ( The curable composition as described in any one of Claims 1-9 which mix | blends D).   The organic isocyanate compound (a) and the hydroxyl group-containing compound (b) are reacted at a reaction molar ratio of the number of moles of isocyanate groups / the number of moles of hydroxyl groups of 1.2 to 1.8, and the unreacted organic isocyanate compound (a) Step (I) for synthesizing an isocyanate group-containing urethane prepolymer (A) having a content of 1.5% by mass or less, Step (II) for synthesizing a block amine compound (B), and an isocyanate group-containing urethane prepolymer (A The content of the low molecular weight organic isocyanate compound (C) is characterized by having a step (III) of blending the block amine compound (B) with the curable composition in an amount of 0.5% by mass or less. A method for producing a curable composition.