JP5446153B2 - Latent curing agent and curable resin composition using the same - Google Patents

Description

  The present invention relates to a latent curing agent and a curable resin composition using the same, and more particularly to an oxazolidine compound and a two-component curable polyurethane resin composition using the same.

Polyurethane resins with urethane prepolymer as a curing component are one-component moisture-curing type that is cured by moisture in the air and two-component curing type that is cured by mixing with a curing agent component that reacts with isocyanate such as polyol. It is classified and used.
Of these, the two-component type is less susceptible to foaming than the one-component type, and can be cured in a short time. Therefore, coating materials, sealing materials, waterproofing materials, flooring materials, adhesives, etc. It is used for such as.

  However, in the conventional two-component curable polyurethane resin composition, it is difficult to balance the storage stability (workability) of the base material component and the curability after mixing the base material component and the curing agent component, and foaming. In order to suppress this, there has been a problem that it is necessary to use a highly harmful metal catalyst that can promote the reaction between a lead-based isocyanate and a polyol.

  For such a problem, for example, in Patent Document 1, a main component is a terminal free isocyanate group-containing urethane prepolymer obtained by reacting polyisocyanate, a compound having active hydrogen and N-hydroxyalkyl-oxazolidine. A two-component curable polyurethane resin composition comprising a main component that is composed of water as a curing component and a curing agent that includes 0.1 to 20% by weight of an oxazolidine ring opening accelerator is proposed.

  Further, the present applicant also stated that “a two-component curable polyurethane resin composition comprising a substrate containing a urethane prepolymer and a curing agent containing a compound having two or more active hydrogen groups, A two-component curable polyurethane resin composition containing bismuth organic acid and an oxazolidine compound in the material and / or the curing agent has been proposed (see Patent Document 2).

JP 2001-19734 A JP 2006-282963 A

  However, in the case of the oxazolidine ring-opening accelerator described in Patent Document 1 and the oxazolidine compound described in Patent Document 2, the present inventor may volatilize benzaldehyde etc. outside the system (in the atmosphere) by hydrolysis depending on the type. Therefore, it was made clear that improvement is necessary from the viewpoint of environmental measures.

  Therefore, the present invention has an excellent balance between the storage stability (workability) of the base material component and the curability after mixing the base material component and the curing agent component, has good foam resistance, and volatilizes outside the system. It is an object of the present invention to provide a curable resin composition capable of reducing components and a latent curing agent used therefor.

As a result of diligent research to solve the above problems, the inventor of the present invention uses the oxazolidine-based latent curing agent represented by a specific structural formula, so that the storage stability (workability) of the base component and the base It has been found that a curable resin composition having an excellent balance with curability after mixing of a material component and a curing agent component, having good foam resistance, and capable of reducing volatile components outside the system can be obtained. Completed the invention.
That is, the present invention provides the following (i) to ( iv ).

(I) represented by the following formula (1) or (2), a latent curing agent that contribute to the amino group and hydroxyl curing reaction that occurs by ring opening of the oxazolidine ring by moisture.

In the formula, n represents an integer of 0 to 2, R ¹ is a hydroxyl group or an alkyl group or an alkoxy group having 1 to 12 carbon atoms which may be branched, and R ¹ when n is 2, They may be the same or different. R ² is an alkyl group or an alkoxy group which may have 1 to 6 carbon atoms and may have a hydroxyl group. R ³ and R ⁴ are each independently a hydrogen atom, an alkyl group having 1 to 6 carbon atoms, or a phenyl group.

  (Ii) The latent curing agent according to (i) above, which is a reaction product of a cinnamaldehyde derivative and monoethanolamine or diethanolamine.

  (Iii) The latent curing agent according to (ii), wherein the cinnamaldehyde derivative has a boiling point of 200 ° C. or higher.

( Iv ) A two-component curable polyurethane resin composition comprising a base material component containing a urethane prepolymer having an isocyanate group at the molecular end and a curing agent component containing a compound having two or more active hydrogen groups. ,
A two-component curable polyurethane resin composition containing the latent curing agent according to any one of (i) to (iii) in the base material component and / or the curing agent component.

As described below, according to the present invention, the balance between the storage stability (workability) of the base material component and the curability after mixing the base material component and the curing agent component is excellent, and the foam resistance is also good. Thus, it is possible to provide a curable resin composition that can reduce volatile components to the outside of the system and a latent curing agent used therefor.
The curable resin composition of the present invention is useful because it can be suitably used for various sealing materials, joint materials, adhesives, paints, waterproofing materials, flooring materials and the like.

The present invention is described in detail below.
The latent curing agent of the present invention is a latent curing agent represented by the following formula (1) or (2).
By using the oxazolidine compound represented by such a structural formula as a latent curing agent, the resulting curable resin composition of the present invention (particularly a two-component curable polyurethane resin composition) can store a base component. It is excellent in balance between stability (workability) and curability after mixing the base material component and the curing agent component, has good foam resistance, and can reduce volatile components outside the system.
This is because the oxazolidine compound traps moisture (water) in the atmosphere to suppress foaming due to the carbon dioxide removal reaction, and the amino group and hydroxyl group generated by the opening of the oxazolidine ring by moisture contribute to the curing reaction. This is thought to be because the cinnamaldehyde derivative produced simultaneously has a high boiling point and remains in the system.

The formula (1), n represents an integer of 0 to 2, R ¹ is branched hydroxyl or 1 to 12 carbon atoms is also alkyl or alkoxy group, when n is 2 R ¹ may be the same or different. Specifically, for example, linear alkyl groups such as a methyl group, an ethyl group, a propyl group, a butyl group, a pentyl group, an octyl group, and a dodecyl group; an isopropyl group, an isobutyl group, a sec-butyl group, and a tert-butyl group Group, isopentyl group, neopentyl group, tert-pentyl group, 1-methylbutyl group, 1-methylheptyl group and other branched alkyl groups; methoxy group, ethoxy group, propoxy group, butoxy group and other alkoxy groups; It is done.
R ² is an alkyl group or an alkoxy group which may have 1 to 6 carbon atoms and may have a hydroxyl group. Specific examples include those having 6 or less carbon atoms among those exemplified above for R ¹ ; hydroxymethyl group, hydroxyethyl group, hydroxypropyl group, and the like.
R ³ is a hydrogen atom, an alkyl group having 1 to 6 carbon atoms which may be branched, or a phenyl group. Specific examples include those having 6 or less carbon atoms among those exemplified for R ¹ in addition to a hydrogen atom and a phenyl group.

Preferred examples of the compound represented by the above formula (1) include compounds represented by the following formula (1a) and the like.

In the above formula (2), n, R ¹ and R ² are the same as those described in the above formula (1).
R ⁴ is a hydrogen atom, an alkyl group having 1 to 6 carbon atoms which may be branched, or a phenyl group. Specific examples include those having 6 or less carbon atoms among those exemplified for R ¹ in addition to a hydrogen atom and a phenyl group.

Preferred examples of the compound represented by the above formula (2) include compounds represented by the following formulas (2a) and (2b).

  In the above formulas (1) and (2), the oxazolidine compound can be synthesized by reacting a cinnamaldehyde derivative with monoethanolamine, diethanolamine or the like using a solvent capable of removing water such as toluene by azeotropic distillation. it can.

  Here, specific examples of the cinnamaldehyde derivative include cinnamaldehyde (boiling point: 251 ° C.), α-methylcinnamaldehyde (boiling point: 260 ° C.), p-tert-butyl-α-methylhydrocinnamic. Aldehyde (boiling point: 290 ° C), p-isopropyl-α-methylhydrocinnamic aldehyde (boiling point: 270 ° C), α-hexylcinnamaldehyde (boiling point: 305 ° C), α-pentylcinnamaldehyde (boiling point: 288 ° C), And 2-methoxycinnamaldehyde (boiling point: 300 ° C.).

In the present invention, among these cinnamaldehyde derivatives, those having a boiling point of 200 ° C. or higher are preferable.
When the boiling point is 200 ° C. or higher, the volatile components to the outside of the curable resin composition containing the resulting oxazolidine compound (latent curing agent) can be more reliably reduced.

The two-part curable polyurethane resin material composition of the present invention (hereinafter simply referred to as “resin composition of the present invention”) is a urethane prepolymer having an isocyanate group at the molecular end (hereinafter simply referred to as “urethane prepolymer”). ) Containing a base material component and a curing agent component containing a compound having two or more active hydrogen groups,
It is a resin composition containing the latent curing agent of the present invention described above in the base material component and / or the curing agent component.
Next, the base material component and the curing agent component will be described in detail.

<Base material component>
The base material component used in the resin composition of the present invention is not particularly limited as long as it contains a urethane prepolymer.

The urethane prepolymer is a port polyol compound with a polyisocyanate compound, an isocyanate group to the hydroxy group (OH group) (NCO group) of Ru with a reaction product obtained by reacting so that excessive.
Moreover, the said urethane prepolymer can contain 0.5-5 mass% NCO group in a molecular terminal.

(Polyisocyanate compound)
The polyisocyanate compound used in the production of the urethane prepolymer is not particularly limited as long as it has two or more isocyanate groups in the molecule.
Specific examples of the polyisocyanate compound include TDI (for example, 2,4-tolylene diisocyanate (2,4-TDI), 2,6-tolylene diisocyanate (2,6-TDI)), MDI ( For example, 4,4'-diphenylmethane diisocyanate (4,4'-MDI), 2,4'-diphenylmethane diisocyanate (2,4'-MDI)), 1,4-phenylene diisocyanate, polymethylene polyphenylene polyisocyanate, xylylene diene Aromatic polyisocyanates such as isocyanate (XDI), tetramethylxylylene diisocyanate (TMXDI), tolidine diisocyanate (TODI), 1,5-naphthalene diisocyanate (NDI), triphenylmethane triisocyanate; Aliphatic polyisocyanates such as socyanate (HDI), trimethylhexamethylene diisocyanate (TMHDI), lysine diisocyanate, norbornane diisocyanate (NBDI); transcyclohexane-1,4-diisocyanate, isophorone diisocyanate (IPDI), bis (isocyanatomethyl) cyclohexane (H ₆ XDI), cycloaliphatic polyisocyanates such as dicyclohexylmethane diisocyanate (H ₁₂ MDI); carbodiimide-modified polyisocyanates; isocyanurate-modified polyisocyanates; and the like.

  Such polyisocyanate compounds can be used alone or in combination of two or more.

(Polyol compound)
The polyol compound used in the production of the urethane prepolymer is not particularly limited as long as it has two or more hydroxyl groups.
Examples of the polyol compound include polyether polyols, polyester polyols, other polyols, and mixed polyols thereof.

  Examples of the polyether polyol include ethylene glycol, diethylene glycol, propylene glycol, dipropylene glycol, glycerin, 1,1,1-trimethylolpropane, 1,2,5-hexanetriol, 1,3-butanediol, 1, Polyols obtained by adding at least one selected from the group consisting of ethylene oxide, propylene oxide, butylene oxide and polyoxytetramethylene oxide to at least one selected from the group consisting of 4-butanediol and pentaerythritol, etc. Is mentioned. Specifically, polyoxyethylene polyol and polyoxypropylene polyol are preferably exemplified.

  Specifically, the polyester polyol is selected from the group consisting of, for example, ethylene glycol, propylene glycol, butanediol, pentanediol, hexanediol, glycerin, 1,1,1-trimethylolpropane, and other low molecular polyols. A condensation polymer of at least one selected from the group consisting of glutaric acid, adipic acid, pimelic acid, suberic acid, sebacic acid, dimer acid, other aliphatic carboxylic acids and oligomeric acids; Ring-opening polymers such as lactone and valerolactone; and the like.

  Specific examples of other polyols include, for example, polymer polyol, polycarbonate polyol; polybutadiene polyol; hydrogenated polybutadiene polyol; acrylic polyol; ethylene glycol, diethylene glycol, propylene glycol, dipropylene glycol, butanediol, pentanediol, And low molecular weight polyols such as hexanediol.

Such polyol compounds can be used alone or in combination of two or more.
Of these, polyoxyethylene polyols and polyoxypropylene polyols are suitable for the viscosity of the urethane prepolymer obtained, and a cured product comprising the resin composition of the present invention obtained using this urethane prepolymer. This is preferable because the elongation and strength of the resin are appropriate.

  In the present invention, the amount of the polyisocyanate compound and the polyol compound when producing the urethane prepolymer is preferably such that the NCO group / OH group (equivalent ratio) is 1.2 to 2.5, More preferably, it is 1.5 to 2.2. When the equivalence ratio is within such a range, the viscosity of the obtained urethane prepolymer becomes appropriate, and the remaining amount of the unreacted polyisocyanate compound in the urethane prepolymer can be reduced.

  In this invention, the manufacturing method of a urethane prepolymer is not specifically limited, For example, it can manufacture by heating and stirring the polyol compound and polyisocyanate compound of the above-mentioned equivalent ratio at 50-130 degreeC. Moreover, if necessary, for example, a urethanization catalyst such as an organic tin compound, organic bismuth, or amine can be used.

  Such urethane prepolymers can be used alone or in combination of two or more.

<Curing agent component>
The curing agent component used in the resin composition of the present invention is not particularly limited as long as it contains a compound having two or more active hydrogen groups.

  Here, the compound having two or more active hydrogen groups is a compound having in the molecule two or more substituents selected from the group consisting of a hydroxyl group, a mercapto group, and an amino group (including an imino group, the same shall apply hereinafter). There are no particular restrictions as long as they are present, and examples thereof include a polyol compound having two or more hydroxyl groups, a polythiol compound having two or more mercapto groups, and a polyamine compound having two or more amino groups, and is preferably a polyol compound.

Specific examples of the polyol compound include, for example, polyol compounds used in the production of the urethane prepolymer described above, and these may be used alone or in combination of two or more.
Of these, polyethylene glycol and polypropylene glycol (PPG) are preferable.

  Specific examples of the polythiol compound include methanedithiol, 1,3-butanedithiol, 1,4-butanedithiol, 2,3-butanedithiol, 1,2-benzenedithiol, and 1,3-benzenedithiol. 1,4-benzenedithiol, 1,10-decanedithiol, 1,2-ethanedithiol, 1,6-hexanedithiol, 1,9-nonanedithiol, 1,8-octanedithiol, 1,5-pentanedithiol, 1,2-propanedithiol, 1,3-propadithiol, toluene-3,4-dithiol, 3,6-dichloro-1,2-benzenedithiol, 1,5-naphthalenedithiol, 1,2-benzenedimethanethiol 1,3-benzenedimethanethiol, 1,4-benzenedimethanethiol, 4,4 ′ Thiobisbenzenethiol, 2,5-dimercapto-1,3,4-thiadiazole, 1,8-dimercapto-3,6-dioxaoctane, 1,5-dimercapto-3-thiapentane, 2-di-n-butyl Examples include amino-4,6-dimercapto-s-triazine, thiol group-terminated polymers (for example, polysulfide polymer (thiocol LP, manufactured by Toray Fine Chemical Co., Ltd.), etc.), and these may be used alone. More than one species may be used in combination.

Specific examples of the polyamine compound include methylenediamine, ethylenediamine, tetramethyl-1,6-hexanediamine, xylylenediamine, tetramethylxylylenediamine, diethylenetriamine, diethylaminopropylamine, N-aminoethylpiperazine , DOO triethylene tetramine, N, N'-dimethylethylenediamine, N, N'-diethyl ethylenediamine, N, N'-diisopropylethylenediamine, N, N'-dimethyl-1,3-propanediamine, N, N'-diethyl-l , 3-propanediamine, N, N′-diisopropyl-1,3-propanediamine, N, N′-dimethyl-1,6-hexanediamine, N, N′-diethyl-1,6-hexanediamine, N, N ′, N ″ -trimethylbis ( Kisamechiren) triamine and the like, may be used those either alone, or in combination of two or more.

  In the present invention, the compound having two or more active hydrogen groups has an equivalent ratio (active hydrogen group / isocyanate group) of the active hydrogen group and the isocyanate group of the urethane prepolymer of 0.3 to 1.3. It is preferable to mix | blend so that it may become, and it is more preferable to mix | blend so that it may become 0.3-1.0.

  The curing agent component used in the resin composition of the present invention can contain an organic acid metal salt as required from the viewpoint of curability of the resin composition of the present invention, in addition to the latent curing agent of the present invention. .

  Specific examples of such an organic metal salt include bismuth organic acid; organic carboxylic acids such as octylic acid, 2-ethylhexylic acid, neodecanoic acid, dodecanoic acid, neododecanoic acid, abietic acid, and neoabietic acid; d -Aliphatic organic acids such as pimaric acid, iso-d-pimalic acid, and podocarp acid; Aliphatic organic acids such as benzoic acid, naphthoic acid, cinnamic acid, and p-oxycinnamic acid; , Tin, titanium, zirconium, calcium, zinc, iron, cobalt, etc.).

  In the present invention, the content of the organic acid metal salt is 100 parts by mass with respect to a total amount of the urethane prepolymer and a compound having two or more active hydrogen groups which may be contained as necessary. The amount is preferably 0.01 to 2 parts by mass, more preferably 0.02 to 1 part by mass in terms of metal amount.

In the resin composition of the present invention, the latent curing agent of the present invention is blended with the base material component and / or the curing agent component described above.
Here, an equivalent ratio (active hydrogen group / isocyanate group) of an active hydrogen group such as an amino group generated by opening of the oxazolidine ring, which is a latent curing agent, and an isocyanate group of the urethane prepolymer is 0.03 to 0.03. It is preferable to blend so as to be 0.6.
Further, the isocyanate group of the urethane prepolymer with respect to the sum of the active hydrogen group such as an amino group generated by the opening of the oxazolidine ring, which is a latent curing agent, and the active hydrogen group of the compound having two or more active hydrogen groups described above. It is preferable to blend so that the equivalent ratio of (active hydrogen group / isocyanate group) is 0.3 to 1.3.

The resin composition of the present invention containing the latent curing agent of the present invention in the base component and / or the hardener component is a mixture of the storage stability (workability) of the base component and the base component and the curing agent component. It is excellent in balance with subsequent curability, has good foam resistance, and can reduce volatile components outside the system.
This is because the oxazolidine compound traps moisture (water) in the atmosphere to suppress foaming due to the carbon dioxide removal reaction, and the amino group and hydroxyl group generated by the opening of the oxazolidine ring by moisture contribute to the curing reaction. It is thought that this is because the cinnamaldehyde derivative produced at the same time remains in the system.

  The base component and / or the curing agent component used in the resin composition of the present invention may be added to other additives such as a plasticizer, a filler, a curing catalyst, and the like as long as the purpose of the present invention is not impaired as necessary. Thixotropic imparting agent, silane coupling agent, pigment, dye, anti-aging agent, antioxidant, antistatic agent, flame retardant, drying oil, adhesion imparting agent, dispersing agent, dehydrating agent, UV absorber, solvent, etc. Can be contained.

Examples of the plasticizer include tetrahydrophthalic acid, azelaic acid, benzoic acid, phthalic acid, trimellitic acid, pyromellitic acid, adipic acid, sebacic acid, fumaric acid, maleic acid, itaconic acid, citric acid and derivatives thereof; And polyester, polyether, epoxy, paraffin, naphthene and aromatic process oils.
Of these, ester plasticizers such as phthalic acid plasticizers and adipic acid plasticizers are preferred.

  Examples of the filler include organic or inorganic materials of various shapes, such as calcium carbonate, carbon black, silica (white carbon), clay talc, iron oxide, zinc oxide, titanium oxide, barium oxide, magnesium oxide, quick lime, Carbonates (eg, magnesium carbonate, zinc carbonate, pepper), alumina hydrate (eg, hydrous aluminum hydroxide), diatomaceous earth, barium sulfate (eg, precipitated barium sulfate), mica, alumina sulfate, lithopone, asbestos, Graphite, molybdenum disulfide, pumice powder, glass powder, silica sand, zeolite; surface treated products of these fatty acids, resin acids, fatty acid esters, higher alcohol addition isocyanate compounds, etc .; glass balloons; resin balloons;

Specific examples of the thixotropic agent include aerosil (manufactured by Nippon Aerosil Co., Ltd.), disparon (manufactured by Enomoto Kasei Co., Ltd.), and the like.
Specific examples of the silane coupling agent include trimethoxyvinylsilane, γ-glycidoxypropyltrimethoxysilane, and the like.

Examples of the pigment include inorganic pigments and organic pigments.
Specific examples of inorganic pigments include, for example, zinc white, titanium oxide, dial, chrome oxide, iron black, composite oxides (for example, titanium yellow, zinc-iron brown, titanium / cobalt green, cobalt green). , Cobalt blue, copper-chromium black, copper-iron black), etc .; chromates such as chrome lead, molybdate orange; ferrocyanides such as bitumen; cadmium yellow, cadmium red, zinc sulfide, etc. Sulfides; sulfates such as barium sulfate; hydrochlorides; silicates such as ultramarine blue; carbonates such as calcium carbonate; phosphates such as manganese violet; hydroxides such as yellow iron oxide; carbons such as carbon black; Metal powder such as aluminum powder and bronze powder; titanium-coated mica;

  Specific examples of organic pigments include monoazo lakes (for example, Lake Red C, Permanen Red 2B, Brilliant Carmine 6B), monoazo (for example, Toluidine Red, Naphthol Red, Fast Yellow G, Benzimidazole Bordeaux). Benzimidazolone brown), disazo series (for example, disazo yellow AAA, disazo yellow HR, pyrazolone red), condensed azo series (for example, condensed azo yellow, condensed azo red, condensed azo brown), metal complex azo series (for example, nickel azo yellow) Azo pigments such as: copper phthalocyanine blue, copper phthalocyanine green, brominated copper phthalocyanine green, and other phthalocyanine pigments; dyes such as basic dye lakes (for example, rhodamine 6 lake); anthraquinone (examples) For example, flavanthrone yellow, dianslaquinolyl red, indanthrene blue), thioindigo (eg, thioindigo Bordeaux), perinone (eg, perinone orange), perylene (eg, perylene scarlet, perylene red, perylene) Maroon), quinacridone series (eg, quinacridone red, quinacridone magenta, quinacridone scarlet), dioxazine series (eg, dioxazine violet), isoindolinone series (eg, isoindolinone yellow), quinophthalone series (eg, quinophthalone yellow), Condensed polycyclic pigments such as isoindoline (for example, isoindoline yellow) and pyrrole (for example, pyrrole red); metal complex azomethine such as copper azomethine yellow; aniline black; daylight fluorescence Fee; and the like.

Specific examples of the dye include direct dyes, vat dyes, sulfur dyes, naphthol dyes, acid dyes, and disperse dyes.
Specific examples of the antioxidant include N, N′-diphenyl-p-phenylenediamine (DPPD), N, N′-dinaphthyl-p-phenylenediamine (DNPD), 2,2,4-trimethyl- Examples include 1,3-dihydroquinoline (TMDQ), N-phenyl-1-naphthylamine (PAN), and hindered phenol compounds.
Specific examples of the antioxidant include hindered phenol compounds such as butylhydroxytoluene (BHT) and butylhydroxyanisole (BHA); triphenyl phosphite: and the like.
Specific examples of the antistatic agent include ionic compounds such as quaternary ammonium salts and amines; hydrophilic compounds such as polyglycols and ethylene oxide derivatives; and the like.
Specific examples of the flame retardant include chloroalkyl phosphate, dimethylmethylphosphonate, bromine / phosphorus compound, ammonium polyphosphate, diethylbishydroxyethylaminophosphate, neopentyl bromide polyether, brominated polyether, and the like. It is done.
Specific examples of the drying oil include linseed oil, soybean oil, dehydrated castor oil, and tung oil.

Specific examples of the adhesion-imparting agent include terpene resins, phenol resins, terpene-phenol resins, rosin resins, xylene resins, and various silane coupling agents.
Specific examples of the dispersant include fatty acid metal salts such as calcium stearate, magnesium stearate, lithium stearate, zinc stearate, aluminum stearate, calcium linoleate, magnesium hydroxystearate; ethyl stearate, lauric acid And fatty acid esters such as ethyl, butyl oleate, dioctyl adipate, and monoglyceride stearate;
Specific examples of the dehydrating agent include methyl stearoxypolysiloxane.
Specific examples of ultraviolet absorbers include, for example, benzophenone ultraviolet absorbers, benzotriazole ultraviolet absorbers, hindered phenol ultraviolet absorbers, salicylate ultraviolet absorbers, cyanoacrylate ultraviolet absorbers, and oxalic acid. Examples include anilide ultraviolet absorbers, formamidine ultraviolet absorbers, triazine ring ultraviolet absorbers, and nickel complex ultraviolet absorbers.
Specific examples of the solvent include hydrocarbons such as hexane and toluene; halogenated hydrocarbons such as tetrachloromethane; ketones such as acetone and methyl ethyl ketone; ethers such as diethyl ether and tetrahydrofuran; ethyl acetate. And ester systems such as

The method for producing the resin composition of the present invention is not particularly limited. For example, the base material component and the curing agent component are mixed, and are used at room temperature or under heating using a roll, kneader, extruder, universal stirrer, and the like ( It can be manufactured at the time of use by sufficiently mixing at 40 to 60 ° C., for example, 40 ° C., and uniformly dispersing (kneading).
In addition, various additives, such as a plasticizer, can also be mix | blended at the time of mixing the said base material component and the said hardening | curing agent component.

  Hereinafter, the present invention will be specifically described with reference to examples. However, the present invention is not limited to these.

Example 1
In 200 g of toluene, 87.7 g (0.6 mol) of α-methylcinnamaldehyde having a boiling point of 260 ° C. and 63.06 g (0.6 mol) of diethanolamine were heated to reflux at 135 ° C., and the desorbed water was azeotroped. The reaction was allowed to proceed for 4 hours.
After the reaction, toluene was removed by reducing the pressure at 110 ° C. to obtain 134.2 g (yield 95.9%) of a compound represented by the following formula (1a). The analysis result of ¹ H-NMR (400 MHz, deuterated chloroform) is shown below.

¹ H-NMR (400 MHz, deuterated chloroform) δ (ppm): 1.91 (3H, CH ₃ ); 2.49, 2.62, 2.90, 3.39 (4H, CH ₂ -N); 3 _{.68 (2H, CH 2 -OH)} ; 4.06 (2H, CH 2 -O); 4.39 (1H, N-CH-O); 6.58 (1H, H-vinyl); 7.24 ~ 7.37 (5H, Ph)

(Example 2)
In 300 g of toluene, 204.3 g (1 mol) of p-tert-butyl-α-methylhydrocinnamic aldehyde having a boiling point of 290 ° C. and 105.1 g (1 mol) of diethanolamine are heated to reflux at 135 ° C. to desorb water. Were removed by azeotropic distillation, but reacted for 2 hours.
After the reaction, toluene was removed by reducing the pressure at 110 ° C. to obtain 290.3 g (yield 99.6%) of a compound represented by the following formula (2a). The analysis result of ¹ H-NMR (400 MHz, deuterated chloroform) is shown below.

¹ H-NMR (400 MHz, deuterated chloroform) δ (ppm): 0.92 (3H, CH ₃ ); 1.31 (9H, CH ₃ ); 1.91 (1H, CH); 2.37 (2H, _{CH 2 Ph); 2.45~3.01,3.23 (4H} , CH 2 -N); 3.68 (2H, CH 2 -OH); 3.90 (2H, CH 2 -O); 4 .12 (1H, N—CH—O); 7.11-7.27 (4H, Ph)

(Example 3)
In 250 g of toluene, 190.28 g (1 mol) of p-isopropyl-α-methylhydrocinnamic aldehyde having a boiling point of 270 ° C. and 105.1 g (1 mol) of diethanolamine were heated to reflux at 135 ° C., and the desorbed water was combined. If removed by boiling, the reaction was allowed to proceed for 2 hours.
After the reaction, toluene was removed by reducing the pressure at 100 ° C. to obtain 272.5 g (yield 98.2%) of a compound represented by the following formula (2b). The analysis result of ¹ H-NMR (400 MHz, deuterated chloroform) is shown below.

¹ H-NMR (400 MHz, deuterated chloroform) δ (ppm): 0.92 (3H, CH ₃ ); 1.32 (6H, CH ₃ ); 1.91 (1H, CH); 2.37 (2H, _{CH 2 Ph); 2.45 (1H} , CHPh); 2.51~3.05,3.26 (4H, CH 2 -N); 3.68 (2H, CH 2 -OH); 3.90 ( 2H, CH ₂ —O); 4.08 (1H, N—CH—O); 7.11 to 7.32 (4H, Ph)

<Manufacture of urethane prepolymer 1>
Polyether polyol (average hydrogen group value 44), which is a mixture of 1000 g of polyoxypropylene diol (hydroxyl value 56.1) having a number average molecular weight of 2,000 and 1000 g of polyoxypropylene triol (hydroxyl value 33.7) having a number average molecular weight of 5,000. .9) was added 952 g of a phthalate ester plasticizer (trade name: DIDP, manufactured by Shin Nippon Rika Co., Ltd.), and 380.3 g of MDI was reacted so that the ratio of NCO / OH = 1.9. thing. The final NCO% was 1.82%.

<Manufacture of latent curing agent>
Latent curing agent 1: Compound (1a) prepared in Example 1
Latent curing agent 2: Compound (2a) prepared in Example 2
Latent curing agent 3: Compound (2b) prepared in Example 3

  Latent curing agent 4: In 250 g of toluene, p-benzaldehyde (1 mol) having a boiling point of 179 ° C. and diethanolamine (1 mol) are heated to reflux at 135 ° C., and the reaction is performed for 2 hours while removing desorbed water by azeotropic distillation. Oxazolidine compound obtained by

  -Latent curing agent 5: obtained by reacting 2-methylpentanal and diethanolamine having a boiling point of 118 ° C in toluene at 250 ° C under reflux at 135 ° C for 2 hours while removing the detaching water by azeotropic distillation. Oxazolidine compounds

(Examples 4-6 and Comparative Examples 1-3)
The base material component containing the obtained urethane prepolymer 1 and any of the latent curing agents 1 to 5 and the curing agent component having the composition shown in Table 1 below were mixed at a mass ratio shown in Table 1 below. Thus, each resin composition was obtained.

The storage stability (workability) of each obtained base material component, and the curability and foam resistance after mixing of each base material component and each curing agent component were measured and evaluated by the following measuring methods. The results are shown in Table 1 below.
Moreover, about the aldehyde compound produced by hydrolysis of the used latent hardening | curing agent, the boiling point and the presence or absence of an aldehyde regulation are shown in following Table 1.

<Storage stability (workability)>
The viscosity (initial viscosity) at a rotation speed of 1 rpm at 20 ° C. and 55% RH (relative humidity) immediately after the preparation of each base material component was measured using a BS viscometer. Measurements were made using a 7 rotor.
In addition, the viscosity after curing for 1 day at 70 ° C. (viscosity after curing) of each obtained base material component was measured by the same method.
And the viscosity increase rate (after curing / immediately after preparation × 100) was calculated from the initial viscosity and the viscosity after curing.
As a result, if the thickening rate is 130% or less, it can be evaluated that the storage stability (workability) as a base material component is excellent.

<Curing property>
Each of the obtained resin compositions was measured for tack-free time (minutes) in accordance with the tack-free test described in JIS A1439: 2004 “Testing method for building sealing material”.

<Foaming resistance>
50 g of each obtained resin composition was filled in a cylindrical paper cup (diameter: 50 mm, capacity: 100 ml) so as not to entrain bubbles, and placed in a constant temperature and humidity chamber at 40 ° C. and 90% RH (relative humidity). It was left to cure for 3 days.
After curing, the cured product was taken out from the constant temperature and humidity chamber, and the foamed state was observed visually.
The confirmation of the foaming state is performed by cutting the cured product in the vertical direction and confirming the presence or absence of bubbles present inside, evaluating what is found to be a lot of foaming as `` x '', whether foaming is not observed, Very few were evaluated as “◯”.

From the results shown in Table 1 above, the two-component curable polyurethane resin compositions (Examples 4 to 6) containing the latent curing agents obtained in Examples 1 to 3 are the storage stability of the base material (working) It was found that the balance between the property and the curability after mixing the base material component and the curing agent component is excellent, the foaming resistance is good, and the volatile components outside the system can be reduced.
In contrast, the two-component curable polyurethane resin compositions (Comparative Examples 1 and 2) containing a conventionally known oxazolidine compound as a latent curing agent are more stable in storage (workability) than Examples 4-6. It was found that Comparative Example 1 has a large amount of volatile components outside the system of aldehydes that are regulated by the aldehyde law.
Moreover, it turned out that the two-component curable polyurethane resin composition containing no oxazolidine compound (Comparative Example 3) is inferior in curability and inferior in foamability.

Claims (4)

Represented by the following formula (1) or (2), a latent curing agent that contribute to the amino group and hydroxyl curing reaction that occurs by ring opening of the oxazolidine ring by moisture.
(In the formula, n represents an integer of 0 to 2, R ¹ is a hydroxyl group or an alkyl group or an alkoxy group having 1 to 12 carbon atoms which may be branched, and R ¹ when n is 2, optionally be the same or different, respectively .R ² is, .R ³ and R ⁴ may be branched having 1 to 6 carbon atoms, an alkyl group or alkoxy group which may have a hydroxyl group Are each independently a hydrogen atom, an alkyl group having 1 to 6 carbon atoms, or a phenyl group.)   The latent curing agent according to claim 1, which is a reaction product of a cinnamaldehyde derivative and monoethanolamine or diethanolamine.   The latent curing agent according to claim 2, wherein the cinnamaldehyde derivative has a boiling point of 200 ° C. or higher. A two-component curable polyurethane resin composition comprising a base material component containing a urethane prepolymer having an isocyanate group at a molecular terminal and a curing agent component containing a compound having two or more active hydrogen groups,
The two-component curable polyurethane resin composition containing the latent curing agent according to any one of claims 1 to 3 in the base material component and / or the curing agent component.