JP6070128B2 - Curable resin composition - Google Patents

Description

  The present invention relates to a curable resin composition.

  Sealing materials are widely used in buildings and the like for filling joints and gaps between various members to ensure watertightness and airtightness. Typical sealing materials for buildings include sealing materials made of urethane resin, modified silicone resin, silicone resin, polysulfide resin and the like. Due to differences in curing methods, the sealing material has a two-component type (two-component type) that is cured by mixing the main agent and the curing agent, and a one-component type (one-component type) that is cured using moisture and oxygen in the air. )

  Of these, one-component sealants, especially one-component urethane sealants composed of urethane prepolymers containing isocyanate groups at the end, do not require the mixing of the main agent and curing agent, and are easy to work, adhesive and durable. The amount of use is increasing year by year because of its superiority (see, for example, Patent Documents 1 and 2).

  In addition, architectural sealing materials are required to exhibit adhesion to difficult-to-adhere coating surfaces such as acrylic electrodeposition coating surfaces and fluorine coating surfaces.

  Therefore, in order to improve adhesion to a difficult-to-adhere adhesive surface in a one-component urethane resin composition, a method of applying a primer to the adhesive surface as a pretreatment or increasing the isocyanate content in the curable composition There are methods.

  Patent Document 1 discloses a moisture curable polyurethane resin composition containing a polysulfide and having a urethane prepolymer having two or more aliphatic isocyanate groups per molecule and a compound having two or more oxazolidine rings per molecule. It is disclosed that it has excellent weather resistance and good curability.

  Patent Document 2 discloses a hydroxy group-containing polysulfide polymer having a hydroxy group (A) obtained by a reaction between a polysulfide polymer having a thiol group and a hydroxyl-terminated polyalkylene glycol mono (meth) acrylate and / or hydroxyalkyl (meth) acrylate. ) And a polyoxyalkylene polyol (B), the urethane prepolymer mixture containing the urethane prepolymer (D) obtained by reacting the polyisocyanate compound (C) has compatibility, storage stability, and curing. It is disclosed that it is excellent in performance.

Japanese Patent Laid-Open No. 9-241501 JP 2011-127027 A

  However, it is laborious and expensive to apply a primer as a pretreatment to the adhesion surface of a difficult-to-adhere coating surface.

  In addition, when the isocyanate content in the composition is increased in order to improve the adhesion to the difficult-to-adhere coating surface, foaming bulge is liable to occur at the time of curing, resulting in peeling from the adherend.

  An object of this invention is to provide the curable resin composition which can improve adhesiveness with respect to a difficult-to-adhere coating surface, and can suppress foaming swelling in view of the said problem.

The present invention includes the following (1) to (2).
(1) a urethane prepolymer (B) having an isocyanate group at a terminal obtained by reacting a polyisocyanate compound with a mixture of a disulfide-containing polyol compound (A) and a polyoxyalkylene polyol;
An oxazolidine compound (C),
The curable resin composition, wherein the disulfide-containing polyol compound (A) is a secondary alcohol.
(2) The curable resin composition according to claim 1, wherein the disulfide-containing polyol compound (A) is obtained by a reaction between a disulfide-containing terminal thiol compound and an epoxy compound.

  ADVANTAGE OF THE INVENTION According to this invention, adhesiveness can be improved with respect to a difficult-to-adhere coating surface, and foaming can be suppressed.

  The present invention will be described in detail below. The present invention is not limited by the following modes for carrying out the invention (hereinafter referred to as “embodiments”). In addition, constituent elements in the following embodiments include those that can be easily assumed by those skilled in the art, those that are substantially the same, and those in a so-called equivalent range. Furthermore, the constituent elements disclosed in the following embodiments can be appropriately combined.

  The curable resin composition according to the present embodiment (hereinafter referred to as “the composition of the present embodiment”) is a terminal obtained by reacting a polyisocyanate compound with a mixture of a disulfide-containing polyol compound (A) and a polyoxyalkylene polyol. A curable resin composition comprising a urethane prepolymer (B) having an isocyanate group in the oxazolidine compound (C), wherein the disulfide-containing polyol compound (A) is a secondary alcohol. is there.

<Urethane prepolymer (B)>
The urethane prepolymer (B) contained in the composition of the present embodiment is a urethane prepolymer having a disulfide bond in the molecule and containing a plurality of isocyanate groups at the molecular ends. Hereinafter, the urethane prepolymer (B) of the present embodiment is referred to as “isocyanate group-containing urethane prepolymer (B) or urethane prepolymer (B)”. The urethane prepolymer (B) is preferably liquid at room temperature from the viewpoint of handling. In addition, the room temperature in this embodiment is 20 degreeC or more and 30 degrees C or less, Preferably it is the temperature of 25 degreeC vicinity. The method for producing the urethane prepolymer (B) includes, for example, a polyisocyanate compound in a mixture obtained by mixing a disulfide-containing polyol compound (A) described later and a polyol compound, and an isocyanate group (NCO group) as a hydroxy group (OH group). It is a reaction product obtained by making it react so that it may become excess. The urethane prepolymer (B) generally contains 0.5% by mass or more and 10% by mass or less of NCO groups at the molecular ends.

[Disulfide-containing polyol compound (A)]
The disulfide-containing polyol compound (A) used when producing the urethane prepolymer (B) of this embodiment is obtained by reacting a disulfide-containing terminal thiol compound (hereinafter referred to as “polythiol compound”) with an epoxy compound. It will not specifically limit if a disulfide containing polyol compound (A) is obtained. The disulfide-containing polyol compound (A) can have two hydroxy groups and a disulfide bond. The reaction formula that allows the polythiol compound and the epoxy compound to react to obtain the disulfide-containing polyol compound (A) is represented, for example, by the following reaction formula (1). In the following reaction formula (1), a catalyst or the like is added to the polythiol compound represented by the following formula (I) and the epoxy compound represented by the following formula (II) as necessary, and the reaction is carried out by heating. A disulfide-containing polyol compound (A) represented by the formula (III) can be obtained.

In the reaction formula (1), each R ₁ independently represents C ₂ H ₄ OCH ₂ OC ₂ H ₄ or an alkylene group having 1 to 12 carbon atoms. R ₂ independently represents an aliphatic group or an aromatic group having 1 or more carbon atoms, preferably 2 to 10 carbon atoms, and may contain an element other than carbon such as oxygen, nitrogen, or halogen in the molecule. A saturated bond may be included. Each x independently represents an integer of 1 to 5, and each n independently represents an integer of 1 to 1500.

In the reaction formula (1), the smaller R ₂ is, the higher the reactivity is. In addition, the larger the R ₂ , the more stable the urethane bond. From the viewpoint of improving the adhesion and weather resistance of the composition of the present embodiment, R ₂ preferably has 4 or more carbon atoms.

  The number average molecular weight of the disulfide-containing polyol compound (A) is 270 or more, preferably 1000 or more and 5000 or less. The adhesiveness of the composition of this embodiment can be improved as the number average molecular weight is within the above range.

  The content of the disulfide-containing polyol compound (A) is preferably larger than 0% by mass and not larger than 20.0% by mass in the total amount of the composition from the viewpoint that it is more excellent in adhesiveness, and more than 5.0% by mass. It is more preferably 0% by mass or less. When the content of the disulfide-containing polyol compound (A) is within the above range, the composition of this embodiment is more excellent in adhesiveness.

  The disulfide-containing polyol compound (A) obtained by the reaction of the polythiol compound and the epoxy compound contained in the composition of the present embodiment is preferably a secondary alcohol. When the disulfide-containing polyol compound (A) is a secondary alcohol, the composition of the present embodiment can improve the adhesion to a difficult-to-adhere coating surface. Also, rather than using the disulfide-containing polyol compound (A) of the primary alcohol, the use of the disulfide-containing polyol compound (A) of the secondary alcohol is more resistant to hydrolysis because the urethane bond is more stable. Can be improved.

  Since the composition of this embodiment can improve the adhesiveness to a difficult-to-adhere coating surface by including the disulfide-containing polyol compound (A), it can be applied to a difficult-to-adhere coating surface without using a primer. Can be glued. Thereby, since it is not necessary to increase the isocyanate content in the composition in order to improve the adhesiveness to the difficult-to-adhere coating surface, it is possible to suppress the expansion of the foam at the time of curing.

(Polythiol compound)
The polythiol compound (disulfide-containing terminal thiol compound) used when the disulfide-containing polyol compound (A) is produced is not particularly limited as long as it is a compound having two or more mercapto groups (thiol groups) in one molecule. Examples of the thiol having two mercapto groups include methanedithiol, ethanedithiol, 1,2-ethanedithiol, propanedithiol, 1,2-propanedithiol, 1,3-propadithiol, butanedithiol, 1,3-butane. Dithiol, 1,4-butanedithiol, 2,3-butanedithiol, pentanedithiol, 1,5-pentanedithiol, hexanedithiol, 1,6-hexanedithiol, 1,8-octanedithiol, 1,9-nonanedithiol, Alkylenedithiols such as 1,10-decanedithiol; benzenedithiol, 1,2-benzenedithiol, 1,3-benzenedithiol, 1,4-benzenedithiol, toluene-3,4-dithiol, 3,6-dichloro- 1,2-benzenedithiol Aromatic dithiols such as 1,5-naphthalenedithiol, 4,4'-thiobisbenzenethiol; benzenedimethanethiol, 1,2-benzenedimethanethiol, 1,3-benzenedimethanethiol, 1,4- Dithiols of aromatic hydrocarbon compounds such as benzenedimethanethiol; 2-di-n-butylamino-4,6-dimercapto-s-triazine, 1,8-dimercapto-3,6-dioxaoctane Such heterocyclic compounds; 2-mercapto-3-thiahexane-1,6-dithiol, 5,5-bis (mercaptomethyl) -3,7-dithianonane-1,9-dithiol, 5- (2-mercaptoethyl) -3,7-dithianonane-1,9-dithiol, 2,5-dimercapto-1,3,4-thiadiazole, 1,5-dimer Thia compounds such as script-3 Chiapentan; dimercaptopropanol, include compounds having a hydroxy group such as dithioerythritol.

  Examples of the thiol having three or more mercapto groups include trithioglycerin, 1,3,5-triazine-2,4,6-trithiol (trimercapto-triazine), trimethylolpropane tristhioglycolate, and trimethylolpropane. Tristhiopropionate, 1,2,4-tris (mercaptomethyl) benzene, 1,3,5-tris (mercaptomethyl) benzene, 2,4,6-tris (mercaptomethyl) mesitylene, tris (mercaptomethyl) Isocyanurates, tris (3-mercaptopropyl) isocyanurate, trithiols such as 2,4,5-tris (mercaptomethyl) -1,3-dithiolane; pentaerythritol tetrakisthioglycolate, pentaerythritol tetrakisthiopropionate, , 2,4,5-tetrakis (mercaptomethyl) benzene, tetra mercaptobutanoic, such as tetra-thiol such as pentaerythritol thiols.

  Further, as the polythiol, a thiol group-terminated polymer (for example, polysulfide polymer “Thioplast polymer: manufactured by ACZO NOBEL Co., Ltd.”, “thiocol LP polymer: manufactured by Toray Fine Chemical Co., Ltd.”) or the like can be suitably used.

  These polythiol compounds may be used alone or in combination of two or more.

(Epoxy compound)
As an epoxy compound used when manufacturing a disulfide containing polyol compound (A), the compound containing an epoxy group in a molecule | numerator and its prepolymer are mentioned, for example. Examples include condensates of epichlorohydrin with hydroxyl groups and amino groups such as ethylene glycol, polyethylene glycol, glycerin, polyglycerin, and bisphenol A, and polyepoxy compounds, diepoxy compounds, monoepoxy compounds, glycidylamine compounds, and the like. Can be mentioned.

  Examples of the polyepoxy compound include sorbitol, polyglycidyl ether, polyglycerol polyglycidyl ether, pentaerythritol polyglycidyl ether, diglycerol polyglycidyl ether, triglycidyl tris (2-hydroxyethyl) isocyanate, glycerol polyglycidyl ether, trimethylol. Examples include propane polyglycidyl ether.

  Examples of the diepoxy compound include neopentyl glycol diglycidyl ether, 1,6-hexanediol diglycidyl ether, resorcin diglycidyl ether, ethylene glycol diglycidyl ether, polyethylene glycol diglycidyl ether, propylene glycol diglycidyl ether, and polypropylene glycol diester. Examples thereof include glycidyl ether and polytetramethylene glycol diglycidyl ether.

  Examples of the monoepoxy compound include ethylene oxide, styrene oxide, cyclohexene oxide, propylene oxide, octylene oxide, dodecene oxide, allyl glycidyl ether, methyl glycidyl ether, ethyl glycidyl ether, butyl glycidyl ether, hexyl glycidyl ether, 2- Ethylhexyl glycidyl ether, phenyl glycidyl ether, alkylphenyl glycidyl ether, para-tert-butylphenyl glycidyl ether, paraxylyl glycidyl ether, glycidyl acetate, glycidyl butyrate, glycidyl hexoate, glycidyl benzoate, glycidyl benzoate, etc. These homopolymers or copolymers may be mentioned.

  Examples of the glycidylamine compound include N, N, N ′, N ′,-tetraglycidyl-m-xylylenediamine, 1,3-bis (N, N-diglycidylamino) cyclohexane and the like.

  Among these, a monoepoxy compound is preferably used from the viewpoint of improving the adhesiveness of the composition of the present embodiment. As the monoepoxy compound, for example, butyl glycidyl ether, allyl glycidyl ether, phenyl glycidyl ether, 2-ethylhexyl glycidyl ether and the like can be suitably used.

  Said epoxy compound can be used individually or in combination of 2 types or more, respectively.

[Polyoxyalkylene polyol]
The polyoxyalkylene polyol used when producing the urethane prepolymer (B) of the present embodiment has a main chain having an oxyalkylene group as a repeating unit, and has two or more hydroxy groups. Examples of the oxyalkylene group include those having 4 to 400 carbon atoms. Of these, an oxyethylene group and an oxypropylene group are preferred from the viewpoint of excellent compatibility and foam resistance and excellent curability.

  As the polyoxyalkylene polyol (polyether polyol), for example, a polyether which is at least one addition polymer selected from the group consisting of ethylene oxide, propylene oxide, butylene oxide and polyoxytetramethylene oxide, ethylene glycol, From the group consisting of diethylene glycol, propylene glycol, dipropylene glycol, glycerin, 1,1,1-trimethylolpropane, 1,2,5-hexanetriol, 1,3-butanediol, 1,4-butanediol and pentaerythritol Examples include polyols obtained by adding at least one selected polyol. Specifically, polyoxypropylene ether polyols such as polyoxyethylene diol, polyoxyethylene triol, polyoxypropylene diol, polyoxypropylene triol, polyoxypropylene ether triol, and polypropylene ethers such as polypropylene ether diol and polypropylene ether triol. A polyol etc. are mentioned suitably. Said polyoxyalkylene polyol can be used individually or in combination of 2 types or more, respectively.

  The polyoxyalkylene polyol is preferably a polyoxypropylene diol or a polyoxypropylene triol from the viewpoint of excellent compatibility and foam resistance and excellent curability.

  The number average molecular weight of the polyoxyalkylene polyol is preferably 300 or more and 200,000 or less, and more preferably 400 or more and 50000 or less, from the viewpoints of excellent compatibility and foam resistance and excellent curability.

  The content of the polyoxyalkylene polyol is preferably larger than 0% by mass and not more than 50.0% by mass in the total amount of the composition from the viewpoints of better compatibility and foam resistance and excellent curability. More preferably, it is 0 mass% or more and 35.0 mass% or less. When the content of the polyoxyalkylene polyol is within the above range, the composition of this embodiment is excellent in compatibility and foam resistance and excellent in curability.

[Polyisocyanate compound]
The polyisocyanate compound contained in the isocyanate group-containing urethane prepolymer (B), which is a urethane prepolymer, is used when the urethane prepolymer is produced, and is particularly limited as long as it has two or more isocyanate groups in the molecule. Not. Examples of the polyisocyanate compound include an aromatic polyisocyanate in which an isocyanate group is bonded to an aromatic hydrocarbon, an aliphatic polyisocyanate in which an isocyanate group is bonded to an aliphatic hydrocarbon, and an isocyanate group having an alicyclic hydrocarbon. And an alicyclic polyisocyanate bonded to the.

  Examples of the aromatic polyisocyanate include toluene such as TDI (for example, 2,4-tolylene diisocyanate (2,4-TDI), 2,6-tolylene diisocyanate (2,6-TDI), or a mixture thereof. Diisocyanate), MDI (e.g., diphenylmethane diisocyanate such as 4,4'-diphenylmethane diisocyanate (4,4'-MDI), 2,4'-diphenylmethane diisocyanate (2,4'-MDI), or mixtures thereof), 1 , 4-phenylene diisocyanate, diphenyl diisocyanate, polymethylene polyphenylene polyisocyanate, tolidine diisocyanate (TODI), 1,5-naphthalene diisocyanate (1,5-NDI), diphenyl ether diisocyanate, trif Such as methane triisocyanate.

  Aliphatic polyisocyanates include propylene diisocyanate, butylene diisocyanate, hexamethylene diisocyanate (HDI), pentamethylene diisocyanate, trimethylhexamethylene diisocyanate (TMHDI), lysine diisocyanate, norbornane diisocyanate (NBDI), xylylene diisocyanate (XDI), tetramethyl. And xylylene diisocyanate (TMXDI).

Examples of the alicyclic polyisocyanate include cyclohexane diisocyanate, methylene bis (cyclohexyl isocyanate), transcyclohexane-1,4-diisocyanate, isophorone diisocyanate (IPDI), bis (isocyanate methyl) cyclohexane (H ₆ XDI), dicyclohexylmethane diisocyanate (H ₁₂ MDI).

  These aromatic polyisocyanates, aliphatic polyisocyanates, alicyclic polyisocyanate carbodiimide-modified polyisocyanates, biuret-modified polyisocyanates, allophanate-modified polyisocyanates, polymethylene polyphenyl polyisocyanates (crude MDI or polymeric MDI), isocyanurates Examples thereof include modified polyisocyanates.

  Such polyisocyanate compounds can be used alone or in combination of two or more. Among these polyisocyanate compounds, TDI and MDI are preferable among the aromatic polyisocyanates and the aliphatic polyisocyanates are preferable because the viscosity becomes low after the reaction and the composition containing the urethane prepolymer becomes easy to handle. Then, among HDI, XDI and alicyclic polyisocyanate, IPDI is preferable.

  The amount of the polyisocyanate compound and the polyol compound (mixture of the disulfide-containing polyol compound (A) and the polyoxyalkylene polyol) in producing the urethane prepolymer (B) is the equivalent ratio of the isocyanate group and the hydroxyl group (isocyanate). Group (NCO group) / hydrosyl group (OH group)) is preferably from 1.2 to 2.5, and more preferably from 1.5 to 2.0. When the equivalence ratio is in such a range, the viscosity of the urethane prepolymer (B) to be obtained becomes appropriate, and the residual amount of the unreacted polyisocyanate compound in the urethane prepolymer (B) can be reduced.

  The production method of the urethane prepolymer (B) is not particularly limited. For example, the polyisocyanate compound and the polyol compound (disulfide-containing polyol compound (A) and polyoxyalkylene polyol having the above-mentioned equivalent ratio (NCO group / OH group) are used. The mixture is heated and stirred at 50 ° C. or higher and 130 ° C. or lower. Moreover, if necessary, for example, a urethanization catalyst such as an organic tin compound, organic bismuth, or amine can be used.

  A urethane prepolymer (B) can be used individually or in combination of 2 types or more, respectively.

<Oxazolidine compound (C)>
The composition of this embodiment can contain the oxazolidine compound (C) which is a hydrolysis-type latent hardening | curing agent which reacts with a water | moisture content as a hardening component, and produces | generates an active hydrogen group.

  The oxazolidine compound (C) contained in the composition of the present embodiment has at least one, preferably 2 to 6, oxazolidine rings in the molecule, which is a saturated 5-membered heterocyclic ring containing an oxygen atom and a nitrogen atom. If it is a compound which has, it will not specifically limit. The oxazolidine compound (C) undergoes hydrolysis by reacting with moisture (humidity) in the atmosphere, and the oxazolidine ring generates (regenerates) a secondary amino group and an alcoholic hydroxyl group, whereby an isocyanate group-containing prepolymer (B ) As a latent curing agent. When the isocyanate group of the isocyanate group-containing prepolymer (B) reacts with moisture, it forms a urea bond and cures. At this time, carbon dioxide gas is also generated, and bubbles due to carbon dioxide gas are generated in the cured product, resulting in deterioration of the appearance. However, when a mixture of the isocyanate group-containing prepolymer (B) and the oxazolidine compound (C) is exposed to moisture, the moisture reacts with the isocyanate groups. The oxazolidine ring of the oxazolidine compound (C) is hydrolyzed by moisture to regenerate secondary amino groups and alcoholic hydroxyl groups, and these active hydrogens react with isocyanate groups to cure without generating carbon dioxide. By doing so, the foaming by the carbon dioxide gas of the composition of this embodiment can be prevented. From the viewpoint of shortening the curing time and storage stability of the composition of the present embodiment, it is preferable to use the oxazolidine compound (C) as a latent curing agent.

  By using the oxazolidine compound (C) as a latent curing agent, the composition of the present embodiment obtained can be moisture-cured at room temperature, is excellent in storage stability, is excellent in curability, and has a curing rate. It can be adjusted and the curing time can be greatly shortened. Also, the foam resistance can be improved.

  Examples of the oxazolidine compound (C) include a urethane bond-containing oxazolidine compound, an ester group-containing oxazolidine compound, an oxazolidine silyl ether, and a carbonate group-containing oxazolidine. These oxazolidine compounds (C) can be obtained by reacting a hydroxyl group of a compound having a hydroxyl group and an oxazolidine ring with an isocyanate group of a polyisocyanate compound or a carboxyl group of an organic carboxylic acid compound. Of these oxazolidine compounds (C), urethane bond-containing oxazolidine compounds are preferred from the viewpoint of easy production and low viscosity.

  Specific examples of the compound having a hydroxyl group and an oxazolidine ring include N-hydroxyalkyloxazolidine obtained by a dehydration condensation reaction between a secondary amino group of an alkanolamine and a carbonyl group of a ketone compound or an aldehyde compound. As a method for synthesizing the compound having a hydroxyl group and an oxazolidine ring, the carbonyl group of the aldehyde compound or the ketone compound is 1.0 times mol or more, preferably 1.0 times the 1.0 mol of the secondary amino group of the alkanolamine. Used in a solvent such as toluene, xylene, etc., and dehydrated while removing by-product water. The method of performing a condensation reaction is mentioned. Excess aldehyde compounds and ketone compounds may be removed by distillation.

  Examples of the alkanolamine include diethanolamine, dipropanolamine, N- (2-hydroxyethyl) -N- (2-hydroxypropyl) amine and the like. Examples of the ketone compound include acetone, diethyl ketone, isopropyl ketone, methyl ethyl ketone, methyl propyl ketone, methyl isopropyl ketone, methyl butyl ketone, methyl isobutyl ketone, methyl tert-butyl ketone, diisobutyl ketone, cyclopentanone, and cyclohexanone. Examples of the aldehyde compound include acetaldehyde, propionaldehyde, n-butyraldehyde, isobutyraldehyde, valeraldehyde, isovaleraldehyde, 2-methylbutyraldehyde, n-hexylaldehyde, 2-methylpentylaldehyde, n-octylaldehyde, 3, 5 Aliphatic aldehyde compounds such as 1,5-trimethylhexylaldehyde; aromatic aldehyde compounds such as benzaldehyde, methylbenzaldehyde, trimethylbenzaldehyde, ethylbenzaldehyde, isopropylbenzaldehyde, isobutylbenzaldehyde, methoxybenzaldehyde, dimethoxybenzaldehyde, and trimethoxybenzaldehyde. Any of these may be used alone or in admixture of two or more.

  Of these, diethanolamine is preferred as the alkanolamine, in terms of ease of production of the compound having a hydroxyl group and an oxazolidine ring, and excellent antifoaming properties when the resulting curable resin composition is cured. Among the aldehyde compounds, aldehyde compounds are preferable, and isobutyraldehyde, 2-methylpentylaldehyde, and benzaldehyde are more preferable.

  Specific examples of the compound having a hydroxyl group and an oxazolidine ring include, for example, 2-isopropyl-3- (2-hydroxyethyl) oxazolidine, 2- (1-methylbutyl) -3- (2-hydroxyethyl) oxazolidine, 3- (2-hydroxyethyl) -2- (1-methylbutyl) oxazolidine, 2-phenyl-3- (2-hydroxyethyl) oxazolidine, 3-phenyl-3-oxazolidineethanol (PHO, manufactured by Yokohama Rubber Co., Ltd.) and the like. It is done.

  As the urethane bond-containing oxazolidine compound, the hydroxyl group and the hydroxyl group of the compound having an oxazolidine ring and the isocyanate group of the organic isocyanate compound have an isocyanate group / hydroxyl molar ratio in the range of 0.9 to 1.2, preferably 0. Suitable examples include those obtained by reacting at a temperature of 50 ° C. or higher and 120 ° C. or lower in the presence or absence of an organic solvent.

  Examples of the organic isocyanate compound used for the synthesis of the urethane bond-containing oxazolidine compound include those similar to those used for the synthesis of the isocyanate group-containing prepolymer (B) described above. Of these, the crystallinity of the urethane bond-containing oxazolidine compound Is preferable, and an aliphatic polyisocyanate is preferable, and hexamethylene diisocyanate (HDI) is particularly preferable in that the workability of the sealing material can be improved.

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

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

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

  Any of these may be used alone or in admixture of two or more.

  The oxazolidine compound (C) does not have an active hydrogen group-containing functional group such as an amino group or a hydroxyl group that reacts with an isocyanate group of a urethane prepolymer containing an isocyanate group at room temperature or an isocyanate group in the molecule. It is preferable. This is to prevent a rise in viscosity of the urethane-based prepolymer and a reduction in foaming prevention performance of the oxazolidine compound (C). However, in the synthesis of the urethane bond-containing oxazolidine compound described above, a small amount of active hydrogen group-containing functional group or isocyanate group may remain in the molecule depending on the molar ratio selected. In this case, the object of the present invention is achieved. It can be regarded as not having above. The “small amount” means that the amount of the active hydrogen group-containing functional group or isocyanate group remaining in the molecule is preferably 0.05 mmol or less, more preferably 0.02 mmol, per 1 g of the oxazolidine compound (C). It is as follows.

  The amount of the oxazolidine compound (C) used is that the active hydrogen of the secondary amino group regenerated by hydrolysis of the oxazolidine compound (C) with respect to 1.0 mol of the isocyanate group in the isocyanate group-containing prepolymer (B). It is preferable to use it so that it may become 0.3 mol or more and 1.0 mol or less, and it is more preferable to use it so that it may become 0.5 mol or more and 1.0 mol or less.

  The content of the oxazolidine compound (C) is 0.1 parts by mass or more and 10 parts by mass with respect to 100 parts by mass of the isocyanate group-containing prepolymer (B) from the viewpoint of adjusting the curing rate of the isocyanate group-containing prepolymer (B). Part by mass or less, preferably 1 part by mass or more and 10 parts by mass or less. When the content of the oxazolidine compound (C) is within the above range, the composition of the present embodiment can be moisture-cured within a predetermined time, is excellent in storage stability, is excellent in curability, and has foam resistance. Can be good. When the content of the oxazolidine compound (C) is less than 0.1 parts by mass, the cured product of the composition of the present embodiment takes too much time until curing, resulting in poor curability and poor foamability. When the content of the oxazolidine compound (C) exceeds 10 parts by mass, the cured product of the composition of the present embodiment becomes too soft and the strength properties of the cured product are deteriorated.

  The composition which concerns on this embodiment can contain various additives other than each component mentioned above as needed in the range which does not impair the objective of this invention. Examples of the additive include a filler, a plasticizer, a pigment, a dye, an anti-aging agent, an antioxidant, an antistatic agent, a flame retardant, an adhesion imparting agent, a stabilizer, a dispersant, and a solvent. Two or more of these may be contained. The additives and the like can be kneaded by a general method to obtain a composition, which can be used for vulcanization or crosslinking. The blending amounts of these additives can be conventional conventional blending amounts as long as the object of the present embodiment is not violated.

  Examples of the filler include organic or inorganic materials having various shapes. For example, wax clay, kaolin clay, calcined clay; silica sand, fumed silica, calcined silica, precipitated silica, ground silica, fused silica; diatomaceous earth; calcium carbonate, heavy calcium carbonate, precipitated calcium carbonate (light calcium carbonate) Colloidal calcium carbonate, iron oxide, zinc oxide, titanium oxide, barium oxide, magnesium oxide; magnesium carbonate, zinc carbonate; organic or inorganic filler such as carbon black; surface treatment with these fatty acids, resin acids, fatty acid esters, etc. Treated products, treated products surface-treated with a fatty acid ester urethane compound, and the like. These may be used alone or in combination of two or more.

  Examples of the plasticizer include polypropylene glycol, diisononyl phthalate (DINP), dioctyl phthalate (DOP), dibutyl phthalate (DBP); dioctyl adipate, isodecyl succinate; diethylene glycol dibenzoate, pentaerythritol ester; butyl oleate And methyl acetylricinoleate; tricresyl phosphate, trioctyl phosphate; propylene glycol adipate polyester, butylene glycol adipate polyester; alkylsulfonic acid phenyl ester (for example, mezamol manufactured by Bayer) and the like. These may be used alone or in combination of two or more.

  The pigment may be either an inorganic pigment or an organic pigment. For example, organic pigments such as titanium dioxide, zinc oxide, ultramarine blue, bengara, lithopone, lead, cadmium, iron, cobalt, aluminum, hydrochloride, sulfate inorganic pigments, azo pigments, copper phthalocyanine pigments, and the like can be used.

  The dye is not particularly limited, and conventionally known dyes can be used. For example, black dye, yellow dye, red dye, blue dye, and brown dye can be mentioned.

  Examples of the antiaging agent include hindered phenol compounds, hindered amine compounds, and benzotriazole compounds.

  Examples of the antioxidant include butylhydroxytoluene (BHT) and butylhydroxyanisole (BHA).

  Examples of the antistatic agent include quaternary ammonium salts; hydrophilic compounds such as polyglycols and ethylene oxide derivatives.

  Examples of the flame retardant include chloroalkyl phosphate, dimethyl / methylphosphonate, bromine / phosphorus compound, ammonium polyphosphate, neopentyl bromide-polyether, and brominated polyether.

  Examples of the adhesion imparting agent include terpene resins, phenol resins, terpene-phenol resins, rosin resins, xylene resins, and various silane coupling agents.

  Examples of the stabilizer include fatty acid silyl esters and fatty acid amide trimethylsilyl compounds.

  The dispersant refers to a substance that makes a solid into fine particles and disperses it in a liquid. Examples thereof include sodium hexametaphosphate, condensed sodium naphthalene sulfonate, and a surfactant.

  The solvent preferably has good compatibility with the solvent contained in the synthesis of other components in the composition of the present embodiment. Examples include methyl ethyl ketone (MEK), ethyl acetate, butyl acetate, cellosolve acetate, mineral spirit, toluene, xylene, and acetone. A solvent can be used individually or in combination of 2 or more types. The solvent is preferably used after sufficiently dehydrated and dried.

  The various additives described above can be used in appropriate combination.

  The method for producing the composition according to the present embodiment is not particularly limited. For example, the above essential components and optional components are rolled, kneader, extruder, universal stirrer under reduced pressure or in an inert gas atmosphere such as nitrogen. And a method of mixing by sufficiently kneading and uniformly dispersing using a stirring device such as a mixing mixer.

  Thus, the composition according to this embodiment includes a urethane prepolymer (B) having an isocyanate group at the terminal obtained by reacting a polyisocyanate compound with a mixture of a disulfide-containing polyol compound (A) and a polyoxyalkylene polyol; By containing the oxazolidine compound (C), it is possible to improve the adhesiveness to the difficult-to-adhere coating surface and to suppress foaming. Also, rather than using the disulfide-containing polyol compound (A) of the primary alcohol, the use of the disulfide-containing polyol compound (A) of the secondary alcohol is more resistant to hydrolysis because the urethane bond is more stable. Can be improved.

  The composition according to the present embodiment is a moisture-curable type, and can be used as a one-component curable composition that is prepared by pre-mixing and storing all of the compounding components in advance and curing with moisture in the air after construction. Further, as a curing agent, components such as a curing catalyst, a filler, a plasticizer, and water are blended in advance and used as a two-component type in which the blending agent (material) and the polymer composition are mixed before use. You can also

  The composition according to the present embodiment is a one-component type, and since all the blending components are blended in advance, the blending components containing moisture are used after being dehydrated and dried in advance, or by reducing the pressure during blending and kneading. It is preferable to dehydrate. When the composition according to this embodiment is exposed to moisture, the oxazolidine compound (C) (latent curing agent) undergoes a curing reaction due to hydrolysis to generate an amino group, and thus has excellent curability. Therefore, the obtained composition according to the present embodiment is stored in a closed container, and a cured product can be obtained at room temperature due to moisture in the air at the time of use. In addition, the curing reaction can be advanced by appropriately supplying water.

  Although the use of the composition according to the present embodiment is not particularly limited, the composition according to the present embodiment has the excellent characteristics as described above, so that it is for civil engineering, concrete, wood, metal, glass It is suitably used for applications such as sealing materials for plastics, adhesives, sealing agents, potting agents, elastic adhesives, coating materials, lining materials, structural adhesives in concrete and mortar, and cracking injection materials.

  As mentioned above, although the curable resin composition of this invention was demonstrated in detail, this invention is not limited to said example, You may perform various change and improvement in the range which does not deviate from the summary of this invention.

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

<Preparation of disulfide-containing polyol compound (A1)>
Disulfide content by adding 0.5 g of triethylamine to 500 g of polythiol (Thioplast polymer G44: manufactured by ACZO NOBEL) and 130.1 g of butyl glycidyl ether (BGE) in a 1 L glass container and reacting at 100 ° C. for 4 hours. A polyol compound (A1) was obtained.

<Preparation of disulfide-containing polyol compound (A2)>
Compound by adding 0.5 g of triethylamine to 500 g of polythiol (thiocol polymer LP282: manufactured by Toray Fine Chemical Co., Ltd.) and 130.1 g of butyl glycidyl ether (BGE) in a 1 L glass container and reacting at 100 ° C. for 4 hours. (A2) was obtained.

<Preparation of disulfide-containing polyol compound (A3)>
A compound (by adding 0.5 g of triethylamine to 500 g of polythiol (Thioplast polymer G44: manufactured by ACZO NOBEL) and 114.1 g of allyl glycidyl ether (AGE) in a 1 L glass container and reacting at 100 ° C. for 4 hours. A3) was obtained.

<Preparation of disulfide-containing polyol compound (A4)>
A compound (by adding 0.5 g of triethylamine to 500 g of polythiol (Thioplast polymer G44: manufactured by ACZO NOBEL) and 150.1 g of phenylglycidyl ether (PGE) in a 1 L glass container and reacting at 100 ° C. for 4 hours. A4) was obtained.

<Preparation of disulfide-containing polyol compound (A5)>
By adding 0.5 g of triethylamine to 500 g of polythiol (Thioplast polymer G44: manufactured by ACZO NOBEL) and 186.3 g of 2-ethylhexyl glycidyl ether (EHGE) in a 1 L glass container, and reacting at 100 ° C. for 4 hours. Compound (A5) was obtained.

<Preparation of urethane prepolymer (B)>
The disulfide-containing polyol compounds (A1 to A6) prepared above as shown in Table 1, polyol compound 1 (polyoxypropylene diol, hydroxyl value 56.1) and polyol compound 2 (polyoxypropylene triol, hydroxyl value 33.7). And a polyether polyol (average hydroxyl value 44.9), which is a mixture thereof, in a mass ratio (parts by mass) shown in the same table and mixed, then the polyisocyanate compound is mass ratio (parts by mass) shown in the same table ) And after dehydration at 120 ° C. under reduced pressure, the polyisocyanate compound was added in an amount such that the NCO group / OH group equivalent ratio was 1.9, and mixed and stirred at 95 ° C. for 24 hours during nitrogen substitution. The indicated urethane prepolymer (B) was prepared. Table 1 shows the amount of each component.

<Preparation of oxazolidine compound (C)>
A reaction vessel equipped with a stirrer, thermometer, ester tube and heating / cooling device was charged with 435 g of diethanolamine (molecular weight 105) and 183 g of toluene, and 328 g of isobutyraldehyde (molecular weight 72.1) was added while stirring. The mixture was heated to 110 ° C. to 150 ° C. for 3 hours, and by-product water was removed from the system to perform reflux dehydration reaction. The amount of water removed was 74.5 g. Subsequently, heating was performed while reducing the pressure from 50 hPa to 70 hPa to remove toluene and unreacted isobutyraldehyde, thereby obtaining 2-isopropyl-3- (2-hydroxyethyl) oxazolidine as an intermediate reaction product. 348 g of hexamethylene diisocyanate (molecular weight 168) was further added to 659 g of the obtained 2-isopropyl-3- (2-hydroxyethyl) oxazolidine, and reacted at 80 ° C. for 8 hours. The time when the measured NCO content by titration was 0.0% by mass was determined as the reaction end point, and a urethane bond-containing oxazolidine compound having a urethane bond and two oxazolidine rings in the molecule was obtained. The obtained urethane bond-containing oxazolidine compound was a translucent liquid at room temperature.

<Preparation of curable resin composition>
The urethane prepolymer (B) obtained above and each component shown in Table 1 below were blended in the mass ratio (parts by mass) shown in Table 1, and these were mixed thoroughly using an electric stirrer or the like. Each composition of Examples 1-5 and Comparative Examples 1-5 was prepared.

  About each composition obtained above, foamability, adhesiveness, and a weather resistance were evaluated by the method shown below. The results are shown in Table 1.

<Foaming properties>
Each composition obtained was cured at 40 ° C. for 3 days, and the surface of the cured composition was visually observed to confirm the presence or absence of foaming. The case where foaming was not confirmed visually was evaluated as “◯”. The case where foaming was confirmed visually was evaluated as “x”. In addition, since it did not harden | cure about Comparative Examples 3 and 4, it described as "hardening failure." The evaluation results are shown in Table 1 below.

<Adhesiveness (peel test)>
Each composition obtained was applied to a melamine resin-coated super-weather-resistant acrylic electrodeposition coated plate (aluminum plate) to prepare an H-type tensile test body (hereinafter referred to as a test body). The specimen was cured under conditions.
(Curing and curing conditions)
Adhesion: Cured for 7 days under conditions of 23 ° C. and 50% RH.

About each obtained test body, the 90 degree peeling test (peel test) of each composition was done by the method shown below, and the destruction state was evaluated. The composition was peeled off at 90 degrees with respect to the adherend. The evaluation results are shown in Table 1 below. In addition, since it did not harden | cure about Comparative Examples 3 and 4, it described as "hardening failure." In Table 1, the evaluation criteria for CF and AF are as follows.
(Evaluation criteria)
-CF: What caused the cohesive failure of the sealing material-AF: What caused the interface failure between the adherend and the sealing material CF was evaluated to be superior in adhesiveness.

<Weather resistance>
About each obtained test body, according to JISD0205, the acceleration test (black panel temperature 63 degreeC, 1 cycle 60 minutes (water spray cycle 12 minutes, spray stop 48 minutes) of each composition by 1 in accordance with JIS D0205 A spray cycle was performed for 500 hours), and the weather resistance was evaluated. The surface of the specimen after the acceleration test was visually observed to check for cracks or choking. The case where no crack or choking was confirmed by visual observation was evaluated as “◯”. The case where cracking or choking was confirmed by visual observation was evaluated as “x”. In addition, since it did not harden | cure about Comparative Examples 3 and 4, it described as "hardening failure." The evaluation results are shown in Table 1 below.

Each component shown in Table 1 is as follows.
Disulfide-containing polyol compound (A1 to A5): Disulfide-containing polyol compound prepared as described above, manufactured by Yokohama Rubber Co., Ltd. Disulfide-containing polyol compound (A6): molecular weight 1000-3000 having primary hydroxyl groups at both ends Disulfide-containing polyol compound, manufactured by Yokohama Rubber Co., Ltd. Urethane prepolymer (B): urethane prepolymer prepared above, manufactured by Yokohama Rubber Co., Ltd. Polysulfide polymer 1: Thioplast polymer, trade name “G44”, ACZO NOBEL Co., Ltd. ・ Polysulfide polymer 2: thiocol polymer, trade name “LP-282”, manufactured by Toray Fine Chemical Co., Ltd. ・ Polyol compound 1: polyoxypropylene diol, number of functional groups 2, number average molecular weight 3200, quotient Name “Exenol 3020”, manufactured by Asahi Glass Co., Ltd. ・ Polyol compound 2: polyoxypropylene triol, functional group number 3, number average molecular weight 5100, trade name “Excenol 5030”, manufactured by Asahi Glass Co., Ltd. ・ Polyisocyanate compound: diphenylmethane diisocyanate (MDI) Manufactured by Nippon Polyurethane Industry Co., Ltd. ・ Oxazolidine compound (C): the oxazolidine compound prepared above, 3- (2-hydroxyethyl) -2- (1-methylbutyl) oxazolidine, trade name “PHO”, Yokohama Made by Rubber Co., Ltd. ・ Calcium carbonate: Surface treated calcium carbonate, trade name “Sealet 200”, made by Maruo Calcium Co., Ltd. ・ Solvent: Mineral Spirit, trade name “A Solvent”, made by Nippon Oil Corporation ・ Plasticizer: Phthalic acid Diisononyl ( INP), New Japan Chemical Co., Ltd.

<Foaming properties>
From the results shown in Table 1, in Examples 1 to 5, it was confirmed that all of the foaming properties were “◯” and excellent in foaming properties. On the other hand, Comparative Examples 1 and 5 were “◯” and the foamability was good, but Comparative Example 2 was “x” and it was confirmed that the foamability was poor. In Comparative Examples 3 and 4, it was not possible to evaluate because it was not cured. From this, it was found that the composition not containing the oxazolidine compound (C) (see Comparative Example 2) was inferior in foamability.

<Adhesiveness>
From the results shown in Table 1, it was confirmed that in Examples 1 to 5, the adhesiveness was CF (cohesive failure), and all were excellent in adhesiveness. On the other hand, in Comparative Examples 1 and 2, it was AF (interface fracture), and it was confirmed that the adhesiveness was inferior. In Comparative Examples 3 and 4, it was not possible to evaluate because it was not cured. In Comparative Example 5, it was CF and it was confirmed that the adhesiveness was excellent.

<Weather resistance>
From the results shown in Table 1, it was confirmed that Examples 1 to 5 each had a weather resistance of “◯” and were excellent in weather resistance. On the other hand, Comparative Examples 1 and 2 were “◯”, and it was confirmed that the weather resistance was excellent. In Comparative Examples 3 and 4, it was not possible to evaluate because it was not cured. Comparative Example 5 was “x”, and it was confirmed that the weather resistance was poor.

  From the above, it was confirmed that Comparative Example 1 containing no disulfide-containing polyol compound and Comparative Example 2 containing no oxazolidine compound were inferior in adhesiveness. It was confirmed that Comparative Examples 3 and 4 in which the disulfide-containing terminal thiol compound (polythiol compound) and the epoxy compound were not reacted and the disulfide-containing terminal thiol compound (polysulfide polymer) were used as they were did not cure, so that the curability was inferior. It was. In Comparative Example 5, the disulfide-containing polyol compound was a primary alcohol, and it was confirmed that the weather resistance was poor as compared with the secondary alcohols of Examples 1 to 5.

  Accordingly, the mixture of the disulfide-containing polyol compound (A) and the polyoxyalkylene polyol contains the urethane prepolymer (B) having an isocyanate group at the terminal obtained by reacting the polyisocyanate compound and the oxazolidine compound (C), and the disulfide. The curable resin composition in which the contained polyol compound (A) is a secondary alcohol can improve adhesion to a difficult-to-adhere coating surface as compared with conventional compositions and suppress foaming. And excellent weather resistance. Therefore, since the composition of this example is excellent in foamability, adhesiveness, and weather resistance, it has been found that a highly reliable curable resin composition can be obtained as a composition such as a sealing material and an adhesive. .

Claims (1)

A urethane prepolymer (B) having an isocyanate group at a terminal obtained by reacting a polyisocyanate compound with a mixture of a disulfide-containing polyol compound (A) and a polyoxyalkylene polyol;
An oxazolidine compound (C),
The disulfide-containing polyol compound (A) is a secondary alcohol, a curable resin composition characterized and this obtained by the reaction of the disulfide-containing terminal thiol compound and an epoxy compound.