JP4872380B2 - Curable resin composition - Google Patents

Description

  The present invention relates to a curable resin composition.

One-pack or two-pack polyurethane curable resin compositions are frequently used for applications such as sealing materials, adhesives, coating materials, primers, and paints.
Regarding such a one-pack type or two-pack type polyurethane curable resin composition, the applicant previously proposed a one-pack curable resin composition and a two-pack curable resin composition in Patent Document 1.

  In the one-component curable resin composition described in Patent Document 1, the isocyanate group of the urethane prepolymer having an isocyanate group bonded to a secondary or tertiary aliphatic carbon atom is substituted with the α-position carbon atom of the nitrogen atom. It is a one-component curable resin composition containing a block urethane formed by blocking with a secondary amine having a substituent and an amine-based latent curing agent.

  In addition, the two-component curable resin composition described in Patent Document 1 is used to convert the isocyanate group of the urethane prepolymer having an isocyanate group bonded to a secondary or tertiary aliphatic carbon atom to an α-position carbon of a nitrogen atom. It is a two-component curable resin composition containing a block urethane formed by blocking with a secondary amine having a substituent at an atom, and an amine curing agent.

JP 2003-048949 A

  However, the present inventor has found that the one-part curable resin composition and the two-part curable resin composition described in Patent Document 1 have room for improvement in the adjustment of the pot life.

  Therefore, an object of this invention is to provide the curable resin composition which can adjust the length of pot life.

As a result of intensive studies to achieve the above-mentioned problems, the present inventor contains a specific urethane prepolymer, a moisture latent curing agent containing ketimine and / or oxazolidine, and a blocking agent containing pyrazole and / or oxime. It was found that the curable resin composition to be adjusted can adjust the length of pot life, and the present invention has been completed.
That is, the present invention provides the following (1) to (3).

(1) A urethane prepolymer having an isocyanate group bonded to a tertiary carbon atom, a moisture latent curing agent containing ketimine and / or oxazolidine, and a blocking agent containing a pyrazole compound and / or oxime. Curable resin composition (hereinafter referred to as “the curable resin composition of the first aspect of the present invention”).

(2) Blocking that can be obtained by reaction of a part or all of the isocyanate group of the urethane prepolymer having an isocyanate group bonded to a tertiary carbon atom with a blocking agent containing a pyrazole compound and / or an oxime. Urethane prepolymer,
A curable resin composition containing a moisture latent curing agent containing ketimine and / or oxazolidine (hereinafter referred to as “the curable resin composition of the second aspect of the present invention”).

(3) The curable resin composition according to (1) or (2), further containing an epoxy resin.

  In the curable resin composition of the present invention, the length of pot life can be adjusted.

The present invention is described in detail below.
First, the curable resin composition of the 1st aspect of this invention is demonstrated.
The first curable resin composition of the present invention comprises a urethane prepolymer having an isocyanate group bonded to a tertiary carbon atom, a moisture latent curing agent containing ketimine and / or oxazolidine, a pyrazole-based compound, and / or A curable resin composition containing an oxime-containing blocking agent.

The urethane prepolymer having an isocyanate group bonded to a tertiary carbon atom will be described below.
The urethane prepolymer used is not particularly limited as long as it has an isocyanate group bonded to a tertiary carbon atom.

  Examples of the urethane prepolymer include polymers that can be obtained by a reaction between a polyisocyanate compound having an isocyanate group bonded to a tertiary carbon atom and a polyol compound.

  The polyisocyanate compound having an isocyanate group bonded to a tertiary carbon atom can be specifically represented by the following formula (1).

In the formula, R ^a , R ^b and R ^c are each independently an organic group optionally containing O, S and N, and p is an integer of 1 or more.

  Examples of the organic group include hydrocarbon groups such as an alkyl group, an alicyclic group, an aromatic ring group, and an alkylaryl group. The organic group can include, for example, a functional group such as a carbonyl group, a urea group (carbamide group) or an isocyanate group; a bond such as an ether bond, an amide bond or a urethane bond.

The organic group represented by R ^a or R ^b is preferably a methyl group.

p is an integer of 1 or more, and is preferably an integer of 2 or more. In addition, when p is 1, the polyisocyanate compound represented by the formula (1) may contain one or more isocyanate groups in at least one organic group of R ^a , R ^b and R ^c. it can.

  The polyisocyanate compound preferably has two or more isocyanate groups bonded to tertiary carbon atoms in the molecule.

  Examples of the polyisocyanate compound include polyisocyanate compounds such as m- or p-tetramethylxylylene diisocyanate (TMXDI) represented by the formula (2); isocyanurate bodies and burette bodies of these polyisocyanate compounds; Examples include adducts of these polyisocyanate compounds and polyhydric alcohols such as 1,1,1-trimethylolpropane.

  As an adduct of a polyisocyanate compound and a polyhydric alcohol, for example, it is represented by the formula (3) that can be obtained from m-tetramethylxylylene diisocyanate (TMXDI) and 1,1,1-trimethylolpropane (TMP). And adducts.

  The adduct may contain an unreacted polyisocyanate compound and / or a polyhydric alcohol.

  The polyisocyanate compound is preferably m- or p-tetramethylxylylene diisocyanate represented by the formula (2) from the viewpoint that the pot life can be adjusted long. A polyisocyanate compound can be used individually or in combination of 2 types or more, respectively.

The polyol compound will be described below.
The polyol compound is not particularly limited. For example, polyether polyol, polyester polyol, acrylic polyol, other polyols, and mixed polyols thereof can be mentioned.

  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, One or more polyhydric alcohols such as 4-butanediol, 4,4'-dihydroxyphenylpropane, 4,4'-dihydroxyphenylmethane, pentaerythritol, propylene oxide, ethylene oxide, butylene oxide, styrene Examples include polyether polyols obtained by adding one or more of oxides and the like; polyether polyols obtained by ring-opening polymerization such as tetrahydrofuran.

  Specific examples of the polyether polyol include polytetramethylene glycol obtained by ring-opening polymerization of polyoxyethylene glycol, polyoxypropylene glycol, polyoxypropylene triol, and tetrahydrofuran.

  Examples of the polyester polyol include one or more low molecular polyols such as ethylene glycol, propylene glycol, butanediol, pentanediol, hexanediol, cyclohexanedimethanol, glycerin, and 1,1,1-trimethylolpropane. And a condensation polymer of glutaric acid, adipic acid, pimelic acid, suberic acid, sebacic acid, terephthalic acid, isophthalic acid and one or more of low molecular weight carboxylic acids and oligomeric acids; propionlactone, valerolactone , Ring-opening polymers of lactones such as caprolactone.

The acrylic polyol is a preferred embodiment that is a (meth) acrylic homopolymer or (meth) acrylic copolymer having a hydroxy group.
As a monomer used when manufacturing an acrylic polyol, for example, 2-hydroxyethyl (meth) acrylate, 2-hydroxypropyl (meth) acrylate, 4-hydroxybutyl (meth) acrylate for introducing a hydroxy group is introduced. And combinations of hydroxyalkyl (meth) acrylates such as (meth) acrylic acids and (meth) acrylic acid esters.

The molecular weight of the acrylic polyol is not particularly limited, and is preferably 2000 to 20000.
The hydroxyl value of the acrylic polyol is preferably 20 to 150.
Specific products include, for example, ARUFON UH-2000 (molecular weight 11000, hydroxyl value 20) and ARUFUON UH-2130 (molecular weight 5000, hydroxyl value 33) manufactured by Toagosei Co., Ltd.

  Other polyols include, for example, polymer polyols; polycarbonate polyols; polybutadiene polyols; hydrogenated polybutadiene polyols; low molecular polyols such as ethylene glycol, diethylene glycol, propylene glycol, dipropylene glycol, butanediol, pentanediol, and hexanediol. Is mentioned.

  Of these, polyether polyols and acrylic polyols are preferable from the viewpoints of reactivity and stability.

The polyol compound is preferably a polyether polyol having a weight average molecular weight of 1500 to 15000, and more preferably 2000 to 10,000, since the physical properties after curing are excellent.
A polyol compound can be used individually or in combination of 2 types or more, respectively.

  The mixing ratio of the polyol compound and the polyisocyanate compound is preferably such that the molar ratio (NCO / OH) of the isocyanate group in the polyisocyanate compound to the hydroxy group in the polyol compound is 1.3 to 2.5. More preferably, it is 5 to 2.0. When it is in this range, the viscosity of the urethane prepolymer is moderate and the elongation of the cured product is excellent.

  The urethane prepolymer is not particularly limited for its production. For example, it can be produced according to a conventionally known method. Specifically, for example, a method of heating and stirring the polyol compound and the polyisocyanate compound in the above-mentioned quantitative ratio at 50 to 100 ° C. can be mentioned. If necessary, for example, a urethanization catalyst such as an organic tin compound, an organic bismuth, or an amine can be used.

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

Since the isocyanate group bonded to the secondary carbon atom contained in the conventional urethane prepolymer has less steric hindrance than the case of bonding to the tertiary carbon atom, the reactivity with the moisture latent curing agent is high. Therefore, the present inventor has found that in order to sufficiently secure the pot life, the blocking rate must be increased to nearly 100%, and as a result, the length of the pot life cannot be adjusted. It was.
On the other hand, the urethane prepolymer having an isocyanate group bonded to a tertiary carbon atom has a third isocyanate group bonded to the urethane prepolymer having an isocyanate group bonded to a secondary carbon atom. Due to the large steric hindrance around the secondary carbon atom, the reactivity with the moisture latent curing agent is lower. From this, the present inventor found that the curable resin composition contains a urethane prepolymer having an isocyanate group bonded to a tertiary carbon atom, whereby the length of the pot life can be adjusted longer. The invention was completed.

The moisture latent curing agent will be described below.
The moisture latent curing agent is a curing agent that can be hydrolyzed by moisture in the air or water contained in the composition to generate a compound containing an active hydrogen group. The produced compound containing active hydrogen groups acts as a curing agent. The moisture latent curing agent does not function as a curing agent until a compound containing an active hydrogen group is produced by hydrolysis.

Moisture latent curing agents include ketimine and / or oxazolidine.
Ketimine is a compound that generates a primary amine as a compound containing an active hydrogen group by hydrolysis. The ketimine used is not particularly limited. In the present invention, a compound having a C═N bond (ketimine bond) derived from a ketone or aldehyde and an amine is referred to as ketimine. Therefore, in the present invention, ketimine includes aldimine having a —HC═N bond.

  Examples of the ketimine include those having a structure in which a branched carbon atom or a ring member carbon atom is bonded to the α-position of at least one of the carbon atom or nitrogen atom of the ketimine bond. As a ring member carbon atom, the carbon atom which comprises an aromatic ring and the carbon atom which comprises an alicyclic ring are mentioned, for example.

  Specific ketimines include, for example, (1) ketimines that are reaction products of polyamines and carbonyl compounds, and (2) silicon-containing ketimines that are reaction products of aminoalkoxysilanes and carbonyl compounds.

  The carbonyl compound that is a raw material of ketimine is preferably a ketone or aldehyde having a substituent at the α-position carbon atom of the carbonyl carbon atom because of excellent balance between storage stability and curing rate. Examples of such ketones or aldehydes include compounds represented by the following formula (4).

In Formula (4), R ¹ is a hydrogen atom or a methyl group, R ² is an alkyl group having 1 to 6 carbon atoms, R ³ is a methyl group or an ethyl group, and R ⁴ is a hydrogen atom or a methyl group. Or it is an ethyl group.

Examples of the alkyl group having 1 to 6 carbon atoms of R ² include methyl group, ethyl group, n-propyl group, isopropyl group, n-butyl group, isobutyl group, s-butyl group, t-butyl group, n- Examples include pentyl group, isopentyl group, t-pentyl group, neopentyl group, n-hexyl group, and isohexyl group.

R ² can combine with R ¹ or R ³ to form a ring structure. Examples of the ring structure when R ² is bonded to R ³ include cyclopentane, cyclohexane, and cycloheptane. Examples of the ring structure when R ² is bonded to R ¹ include cyclopentanone, cyclohexanone, and cycloheptanone.

Examples of the compound represented by the formula (4) include methyl isopropyl ketone (MIPK), methyl t-butyl ketone (MTBK), methyl cyclohexyl ketone, and methyl cyclohexanone.
A carbonyl compound can be used individually or in combination of 2 types or more, respectively.

The polyamine which is a raw material of ketimine is not particularly limited as long as it has two or more amino groups. Of these, aliphatic polyamines are preferred from the viewpoint of excellent curing speed.
Examples of aliphatic polyamines include 2,5-dimethyl-2,5-hexamethylenediamine, mensendiamine, 1,4-bis (2-amino-2-methylpropyl) piperazine, and propylene branches at both molecular ends. Polypropylene glycol (PPG) with an amino group bonded to carbon, ethylenediamine, propylenediamine, butylenediamine, diethylenetriamine, triethylenetetramine, tetraethylenepentamine, pentaethylenehexamine, hexamethylenediamine, trimethylhexamethylenediamine, N-aminoethylpiperazine , 1,2-diaminopropane, iminobispropylamine, polyether methyl iminobispropylamine, a methylene group to an amine nitrogen, such as _{H 2 N (CH 2 CH 2} O) 2 (CH 2) 2 NH 2 was bound Skeletal diamine, 1,5-diamino-2-methylpentane, metaxylylenediamine (MXDA), polyamidoamine, isophoronediamine, 1,3-bisaminomethylcyclohexane (1,3BAC), 1-cyclohexylamino-3- Examples thereof include aminopropane, 3-aminomethyl-3,3,5-trimethyl-cyclohexylamine, and dimethyleneamine (NBDA) having a norbornane skeleton. Among these, since the curing speed is high, 1,3-bisaminomethylcyclohexane, dimethyleneamine having a norbornane skeleton, metaxylylenediamine, H ₂ N (CH ₂ CH ₂ O) ₂ (CH ₂ ) ₂ NH ₂ Polyamide amine is preferred.
Polyamines can be used alone or in combination of two or more.

Examples of ketimines that are a reaction product of a polyamine and a carbonyl compound include those obtained from MIPK or MTBK and H ₂ N (CH ₂ CH ₂ O) ₂ (CH ₂ ) ₂ NH ₂ , MIPK or MTBK and 1, Obtained from 3-bisaminomethylcyclohexane, obtained from MIPK or MTBK and dimethyleneamine (NBDA) of norbornane skeleton, obtained from MIPK or MTBK and MXDA, from MIPK or MTBK and polyamidoamine What is obtained is mentioned.

  Among these ketimines, since they are excellent in curability, those obtained from MIPK or MTBK and dimethyleneamine (NBDA) having a norbornane skeleton, obtained from MIPK or MTBK and 1,3-bisaminomethylcyclohexane. Are preferred. Moreover, since the adhesiveness with respect to a wet surface is excellent, what is obtained from MIPK or MTBK and a polyamidoamine is preferable.

  Ketimine, which is a reaction product of a polyamine and a carbonyl compound, is not particularly limited for its production. For example, it can be obtained by heating a carbonyl compound and a polyamine in the absence of a solvent or in the presence of a solvent such as benzene, toluene, xylene, refluxing, and reacting while removing azeotropically removed water.

As an amino alkoxysilane which is a raw material of a silicon containing ketimine, the compound represented by following formula (5) is mentioned, for example.

In formula (5), R ⁵ represents an alkyl group having 1 to 6 carbon atoms, an alkoxy group having 1 to 6 carbon atoms, or a monovalent siloxane derivative. The alkyl group having 1 to 6 carbon atoms is preferably a methyl group, an ethyl group, or a propyl group. As a C1-C6 alkoxy group, a methoxy group, an ethoxy group, and a propoxy group are preferable. As the monovalent siloxane derivative, a silyloxy group is preferable. Among these, a methoxy group and an ethoxy group are more preferable.

R ⁶ represents a divalent hydrocarbon group which may contain a nitrogen atom. Among these, a divalent hydrocarbon group having 1 to 6 carbon atoms is preferable. The divalent hydrocarbon group not containing a nitrogen atom is preferably a methylene group, an ethylene group or a propylene group. The divalent hydrocarbon group containing a nitrogen atom is preferably a group having an imino group (NH) in a hydrocarbon group exemplified by the divalent hydrocarbon group not containing a nitrogen atom. Among these, as R ⁶ , a methylene group, a propylene group, and —C ₂ H ₄ NHC ₃ H ₆ — are more preferable.

R ⁷ represents an alkoxy group. As an alkoxy group, a C1-C6 alkoxy group is preferable, for example, and a methoxy group and an ethoxy group are more preferable.
m represents any one of 0, 1, 2, and 3.

  Examples of the aminoalkoxysilane represented by the formula (5) include compounds represented by the following formulas (6) to (13). Among these, the compounds represented by the formulas (6) to (9) are preferable.

Examples of the silicon-containing ketimine that is a reaction product of an aminoalkoxysilane and a carbonyl compound include a compound represented by the following formula (14) and a polycondensate having a structure represented by the following formula (15) as a main chain skeleton. Is mentioned.

In the formula (14), R ¹ to R ⁴ are the same as R ¹ to R ⁴ in the formula (4), R ⁵ to R ^7, m is R ⁵ to R ⁷ in formula (5), It is synonymous with m.

In the formula (15), R ¹ to R ⁶ have the same meanings as R ¹ to R ⁶ in the formula (14). n represents an integer of 1 or more, preferably an integer of 1 to 50.

  The main chain terminal of the polycondensate represented by the formula (15) includes, for example, a hydrogen atom, a methyl group, an ethyl group, an alkyl group having 1 to 6 carbon atoms such as a propyl group; An alkoxy group having 1 to 6 carbon atoms such as a group; a monovalent siloxane derivative such as a silyloxy group can be bonded.

  The silicon-containing ketimine is not particularly limited for its production. For example, it can be obtained by dehydrating aminoalkoxysilane and carbonyl compound at room temperature or by heating and stirring. The reaction temperature is preferably 20 to 150 ° C, more preferably 50 to 110 ° C. The reaction time is preferably 2 to 24 hours, more preferably 2 to 5 hours.

  Among these ketimines, a reaction product of the compound represented by the formula (10) and MIPK is preferable from the viewpoint of storage stability.

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

Oxazolidine will be described below.
The oxazolidine is not particularly limited as long as it is a compound having an oxazolidine ring. Specific examples include oxazolidine represented by the following formula (16).

In the formula, R ⁸ represents a lower alkyl group such as a methyl group or an ethyl group.
R ⁹ and R ¹⁰ represents an aliphatic hydrocarbon group having 1 to 6 carbon atoms which may contain a hetero atom, or an aromatic hydrocarbon group having 6 to 8 carbon atoms.

Examples of the aliphatic hydrocarbon group having 1 to 6 carbon atoms include methyl group, ethyl group, n-propyl group, isopropyl group, n-butyl group, isobutyl group, s-butyl group, t-butyl group, n- Examples include pentyl group, isopentyl group, t-pentyl group, neopentyl group, n-hexyl group, and isohexyl group. Examples of the aromatic hydrocarbon group having 6 to 8 carbon atoms include a phenyl group, a 2,4-dimethylphenyl group, and a p-methoxyphenyl group. R ⁹ and R ¹⁰ can be bonded to each other to form an alicyclic hydrocarbon group having 6 to 8 carbon atoms.

R ¹¹ represents a hydrogen atom, an alkyl group such as a methyl group, or an alkylene group. The alkylene group can be bonded to, for example, an oxygen atom, a nitrogen atom, or a sulfur atom.
The oxazolidine represented by the formula (16) can generate a secondary amine as a compound containing an active hydrogen group by hydrolysis.

  Specific examples of the oxazolidine include oxazolidine represented by the following formulas (17) to (21).

  Among these, from the viewpoint of storage stability, the compound represented by the formula (17) is preferable. Oxazolidine can be used alone or in combination of two or more.

  In the curable resin composition of the first aspect of the present invention, the moisture latent curing agent only needs to contain at least one of ketimine and oxazolidine, and can contain both ketimine and oxazolidine.

  As the moisture latent curing agent, a moisture latent curing agent other than ketimine and oxazolidine can be used as long as the object and effect of the present invention are not impaired. Examples of moisture latent curing agents other than ketimine and oxazolidine include enamines and silyl mercaptans.

The amount of moisture latent curing agent is determined by the molar ratio of total isocyanate groups (NCO) in the urethane prepolymer to imino groups (NH) and / or amino groups (NH ₂ ) in the cured curing agent [NCO / (NH and / or NH ₂ )] is preferably from 0.1 to 10, and more preferably from 0.5 to 1.2. In such a range, it is excellent in storage stability, adjustment of the pot life, curability and physical properties.

The blocking agent will be described below.
Examples of the blocking agent include pyrazole compounds and / or oximes.

Examples of the pyrazole compound include pyrazole represented by the following formula (22) and pyrazole derivatives.

  Examples of the pyrazole derivative include 3,5-dimethylpyrazole, 3-methylpyrazole, 4-methylpyrazole, 3,4-dimethylpyrazole, 3,4,5-trimethylpyrazole represented by the formula (23), 3 -Ethylpyrazole, 4-ethylpyrazole, 3,4-diethylpyrazole, 3,5-diethylpyrazole, 3,4,5-triethylpyrazole, 3-n-propylpyrazole, 4-n-propylpyrazole, 3,4- Di-n-propylpyrazole, 3,5-di-n-propylpyrazole, 3,4,5-tri-n-propylpyrazole, 3-isopropylpyrazole, 4-isopropylpyrazole, 3,4-diisopropylpyrazole, 3, 5-diisopropylpyrazole, 3,4,5-triisopropylpyrazole, 3-n- Tilpyrazole, 4-n-butylpyrazole, 3,4-di-n-butylpyrazole, 3,5-di-n-butylpyrazole, 3,4,5-tri-n-butylpyrazole, 3-isobutylpyrazole, 4-isobutylpyrazole, 3,4-diisobutylpyrazole, 3,5-diisobutylpyrazole, 3-t-butylpyrazole, 4-t-butylpyrazole, 3,5-di-t-butylpyrazole, 3-phenylpyrazole, 4 -Phenylpyrazole, 3,5-diphenylpyrazole are mentioned.

Among these, from the viewpoint of adjusting the pot life, pyrazole represented by the formula (22) and 3,5-dimethylpyrazole represented by the formula (23) are preferable.
The pyrazole compounds can be used alone or in combination of two or more.

The oxime will be described below.
The oxime is not particularly limited. Examples include cyclohexanone oxime represented by formula (24), acetooxime represented by formula (25), butanone oxime represented by formula (26), formamide oxime, acetamide oxime, diacetyl monooxime, and benzophenone oxime. .

Among these, cyclohexanone oxime represented by formula (24), acetooxime represented by formula (25), and butanone oxime represented by formula (26) are preferable.
An oxime can be used individually or in combination of 2 types or more, respectively.

  In the curable resin composition of the first aspect of the present invention, compounds other than pyrazole compounds and oximes can be used as blocking agents. Examples of blocking agents other than pyrazole compounds and oximes include alcohols, phenols, triazoles, and caprolactams.

  Examples of alcohols include methanol, ethanol, propanol, hexanol, lauryl alcohol, t-butanol, and cyclohexanol. Examples of phenols include xylenol, naphthol, and 4-methyl-2,6-di-t-butylphenol. Examples of triazoles include 1,2,4-triazole.

  The blocking agents can be used alone or in combination of two or more.

  The amount of the blocking agent is such that the molar ratio [(NH and / or OH) / NCO] of the imino group of the pyrazole compound and / or the hydroxy group of the oxime to the isocyanate group contained in the urethane prepolymer is 0.03 to 0.03. 1 is preferable, and 0.1 to 1 is preferable. In the case of such a range, it is excellent in adjusting the length of pot life and curability.

  When the blocking agent contains a compound other than a pyrazole compound and an oxime, the amount of the blocking agent is based on the isocyanate group contained in the urethane prepolymer, the imino group of the pyrazole compound and / or the hydroxy group of the oxime, and The molar ratio of the functional group capable of reacting with the isocyanate group in the blocking agent other than the pyrazole compound and / or oxime is preferably 0.03-1, and preferably 0.1-1. In the case of such a range, it is excellent in adjusting the length of pot life and curability.

  The curable resin composition according to the first aspect of the present invention is one of the preferable aspects that further contains an epoxy resin. By adding an epoxy resin, it has excellent adhesion to mortar and metal.

  The epoxy resin is not particularly limited. For example, an epoxy resin having a bisphenyl group such as bisphenol A type, bisphenol F type, brominated bisphenol A type, hydrogenated bisphenol A type, bisphenol S type, bisphenol AF type, or biphenyl type. Compound, polyalkylene glycol type, alkylene glycol type epoxy compound, epoxidized resin having naphthalene ring, bifunctional glycidyl ether type epoxy resin such as epoxy compound having fluorene group; phenol novolak type, orthocresol novolak type, Trifunctional or higher glycidyl ether type epoxy resin such as DPP novolac type, trishydroxyphenylmethane type, tetraphenylolethane type; glycidyl ester type epoxy of synthetic fatty acid such as dimer acid Fats; N, N, N ′, N′-tetraglycidyldiaminodiphenylmethane (TGDDM), triglycidyl isocyanurate, tetraglycidyl-m-xylylenediamine, N, N-diglycidylaniline, triglycidyl-p-aminophenol Such a glycidylamino type epoxy resin is mentioned.

Among these, bisphenol A type is preferable.
The epoxy resin is preferably in a liquid state from the viewpoint of handling.
An epoxy resin can be used individually or in combination of 2 types or more, respectively.

  The amount of the epoxy resin is preferably 0.1 to 100 parts by mass and more preferably 0.5 to 10 parts by mass with respect to 100 parts by mass of the urethane prepolymer. In such a range, the curability and physical properties are excellent.

  The curable resin composition of the first aspect of the present invention contains additives in addition to the above-mentioned urethane prepolymer, moisture latent curing agent and blocking agent as long as the object of the present invention is not impaired. Can do. Examples of additives include fillers, plasticizers, antioxidants, anti-aging agents, inorganic pigments, organic pigments, adhesion promoters, flame retardants, dehydrating agents, solvents, silane coupling agents, thixotropic agents, and antistatic agents. Agents. The amount of the additive is not particularly limited, and an amount that can be generally used in a urethane-based composition can be blended.

Examples of the silane coupling agent include epoxy silane such as γ-glycidoxypropyltrimethoxysilane.
From the viewpoint of stability, the amount of the silane coupling agent used is preferably 0.1 to 10 parts by mass, more preferably 0.5 to 3 parts by mass with respect to 100 parts by mass of the urethane prepolymer. preferable.

  Examples of the filler include fumed silica, calcined silica, precipitated silica, ground silica, fused silica; diatomaceous earth; iron oxide, zinc oxide, titanium oxide, barium oxide, magnesium oxide; calcium carbonate, magnesium carbonate, zinc carbonate Waxy clay, kaolin clay, calcined clay; carbon black; and these fatty acids, resin acids, fatty acid esters, and urethane compound treated products.

  Examples of the plasticizer include diisononyl adipate, dioctyl phthalate, dibutyl phthalate, butyl benzyl phthalate, dioctyl adipate, isodecyl succinate, diethylene glycol dibenzoate, pentaerythritol ester, butyl oleate, methyl acetylricinoleate, tricresyl phosphate, phosphorus Examples include trioctyl acid, propylene glycol adipate polyester, and butylene glycol polyester adipate.

Examples of the antioxidant include butylhydroxytoluene, butylhydroxyanisole, and triphenyl phosphite.
Examples of the antiaging agent include hindered phenol compounds, benzotriazole compounds, and hindered amine compounds.

Examples of inorganic pigments include titanium dioxide, zinc oxide, ultramarine, bengara, lithopone, lead, cadmium, iron, cobalt, aluminum, hydrochloride, and sulfate.
Examples of organic pigments include azo pigments and copper phthalocyanine pigments.
Examples of the adhesion imparting agent include terpene resin, phenol resin, terpene-phenol resin, rosin resin, and xylene resin.

Flame retardants include, for example, chloroalkyl phosphate, methylphosphonic acid dimethyl ester, bromine and / or phosphorus atom-containing compounds, ammonium polyphosphate, diethyl bishydroxyethyl aminoethyl phosphate, neopentyl bromide-polyether, brominated poly Ether.
Examples of the dehydrating agent include acyloxysilyl group-containing polysiloxane.

The curable resin composition of the first aspect of the present invention can be used as a one-component or two-component curable resin composition.
As a manufacturing method of the curable resin composition of the 1st aspect of this invention, it is one of the suitable aspects to comprise a mixing process and a heating process, for example.

  When the curable resin composition of the first aspect of the present invention is a one-pack type, the urethane prepolymer, the moisture latent curing agent, and the blocking agent are used as necessary in the mixing step. The epoxy resin and the additive can be thoroughly dried and mixed under the condition of removing moisture to prepare a mixture.

  When the curable resin composition of the first aspect of the present invention is a two-pack type, in the mixing step, for example, a main agent containing a urethane prepolymer and a blocking agent, a moisture latent curing agent, and The epoxy resin and the hardening | curing agent which mixed the additive used according to it are each prepared. One of the preferred embodiments is that the blocking agent is added to at least the main agent. Additives can also be added to the main agent. In the case of a two-component type, a main agent and a curing agent are mixed and used at the time of use.

  In the heating step, the curable resin composition of the first aspect of the present invention is a curable resin composition obtained in the mixing step (the mixture described above in the case of a one-component type. The main agent in the case of a two-component type). Is preferably heated. By heating the mixture or the main agent in the heating step, the isocyanate group in the urethane prepolymer reacts with a blocking agent containing a pyrazole-based compound and / or oxime to block part or all of the isocyanate group, It can be a blocked urethane prepolymer. Thereby, the curable resin composition of the 1st aspect of this invention is excellent in adjustment of the length of pot life, and storage stability.

  In the heating step, the heating temperature is preferably equal to or higher than the melting point of the blocking agent. The pressure is not particularly limited. One of the preferred embodiments is that the heating step is carried out while stirring. The heating step is preferably performed under anhydrous conditions.

After the heating step, a block obtainable by reacting a part or all of the isocyanate groups of the urethane prepolymer having an isocyanate group bonded to a tertiary carbon atom with a blocking agent containing a pyrazole compound and / or an oxime. A curable resin composition containing a fluorinated urethane prepolymer and a moisture latent curing agent containing ketimine and / or oxazolidine can be obtained.
In addition, in the obtained curable resin composition, the unreacted urethane prepolymer which has the isocyanate group couple | bonded with the tertiary carbon atom, and / or the blocking agent may be contained.

  The blocking ratio of the blocked urethane prepolymer is preferably 1 to 100%, and more preferably 5 to 60%. In such a range, it is excellent by adjusting the length of pot life.

Isocyanate groups bonded to secondary carbon atoms contained in conventional urethane prepolymers are highly reactive, and the blocking rate had to be increased to nearly 100% in order to ensure sufficient pot life. This is as described above.
On the other hand, the present inventor found that the isocyanate group bonded to the tertiary carbon atom is less reactive than the isocyanate group bonded to the secondary carbon atom, and further bonded to the tertiary carbon atom. It was discovered that the length of pot life could be adjusted by adjusting the blocking ratio of the urethane prepolymer having an isocyanate group, and the present invention was completed.

The moisture latent curing agent containing ketimine and / or oxazolidine is contained in the curable resin composition as it is without hydrolysis when it is under anhydrous conditions.
The obtained curable resin composition is preferably stored in a container that does not receive moisture.

  As a method of using the curable resin composition of the first aspect of the present invention, for example, it is preferable to include a moisture heating step of heating the curable resin composition of the first aspect of the present invention in the presence of moisture. . When the curable resin composition of the first aspect of the present invention is heated in the presence of moisture, the moisture latent curing agent contained in the curable resin composition is hydrolyzed to produce an amine and react with an isocyanate group. . In the curable resin composition according to the first aspect of the present invention, the isocyanate group is bonded to the tertiary carbon atom, so that the reactivity with the amine is low and the pot life can be extended.

Further, the blocked isocyanate group is heated in the presence of moisture, whereby the blocking agent is removed and an isocyanate group is generated. The produced isocyanate groups react with the amine produced from the moisture latent curing agent and cure.
Further, in the urethane prepolymer, the isocyanate group is partially or wholly blocked, so that the length of pot life can be adjusted by the blocking rate.

  In the moisture heating step, the heating temperature is preferably 50 ° C. or higher, and more preferably 60 to 80 ° C. In such a temperature range, the deblocking reaction tends to proceed. In the moisture heating step, the humidity in the air may be 30% RH or more, or water may be added to the system. In the moisture heating step, for example, it is one of preferred modes that the mixture is stirred with an electric stirrer while heating in a hot tub.

The curable resin composition of the 1st aspect of this invention can be constructed in a construction process after a moisture heating process.
Examples of the adherend include mortar, earthenware, and metal. A construction method in particular is not restrict | limited, For example, it can construct using a brush, a iron, and a roller.

  Applications of the curable resin composition of the first aspect of the present invention include, for example, a sealing material, an adhesive, a coating material, a primer, and a paint.

Next, the curable resin composition of the 2nd aspect of this invention is demonstrated.
The curable resin composition of the second aspect of the present invention is
Blocked urethane prepolymer obtainable by reaction of a part or all of the isocyanate group of the urethane prepolymer having an isocyanate group bonded to a tertiary carbon atom with a blocking agent containing a pyrazole compound and / or oxime When,
A curable resin composition containing a moisture latent curing agent containing ketimine and / or oxazolidine.

The blocked urethane prepolymer will be described below.
The blocked urethane prepolymer is obtained by reacting a part or all of the isocyanate groups of the urethane prepolymer having an isocyanate group bonded to a tertiary carbon atom with a blocking agent containing a pyrazole compound and / or an oxime. Which can be obtained.

  The urethane prepolymer having an isocyanate group bonded to a tertiary carbon atom and the blocking agent containing a pyrazole compound and / or oxime are the same as those of the curable resin composition of the first aspect of the present invention. .

  The amount of the blocking agent is such that the molar ratio [(NH and / or OH) / NCO] of the imino group and / or the oxime hydroxy group of the pyrazole compound in the blocking agent to the isocyanate group contained in the urethane prepolymer. 0.03-1 is preferable, and 0.1-1 is preferable. In such a range, it is excellent in the adjustment of the pot life.

  When the blocking agent contains a compound other than the pyrazole compound and the oxime, the amount of the blocking agent is based on the isocyanate group contained in the urethane prepolymer and the imino group and / or oxime of the pyrazole compound in the blocking agent. The molar ratio of the hydroxyl group and the functional group capable of reacting with the isocyanate group in the blocking agent other than the pyrazole compound and / or oxime is preferably 0.03 to 1, preferably 0.1 to 1. Is preferred. In such a range, it is excellent in the adjustment of the pot life.

  The reaction of the urethane prepolymer having an isocyanate group bonded to a tertiary carbon atom and the blocking agent containing a pyrazole compound and / or oxime is not particularly limited. For example, the urethane prepolymer and the blocking agent may be heated and stirred in the absence of solvent or in a solvent. The reaction temperature is preferably equal to or higher than the melting point of the pyrazole compound. The pressure is not particularly limited.

  The blocking ratio of the obtained blocked urethane prepolymer is preferably 1 to 100%, more preferably 5 to 60%. In such a range, it is excellent by adjusting the length of pot life. In the obtained blocked urethane prepolymer, an unreacted urethane prepolymer having an isocyanate group bonded to a tertiary carbon atom and / or a blocking agent may be contained.

  The blocked urethane prepolymers can be used alone or in combination of two or more. For example, the blocking ratio can be adjusted by blending blocked urethane prepolymers having different blocking ratios.

  The moisture latent curing agent containing ketimine and / or oxazolidine is the same as the curable resin composition of the first aspect of the present invention.

The amount of moisture latent curing agent is determined based on the total isocyanate groups (NCO, blocked isocyanate groups in the urethane prepolymer relative to imino groups (NH) and / or amino groups (NH ₂ ) in the cured curing agent. The molar ratio [including NCO / (NH and / or NH ₂ )] is preferably 0.1 to 10, and more preferably 0.5 to 1.2. In such a range, it is excellent in storage stability, curability, and physical properties.

The curable resin composition of the 2nd aspect of this invention is mentioned as one of the aspects with preferable containing an epoxy resin further. The specific epoxy resin is the same as the above-mentioned epoxy resin.
The amount of the epoxy resin is preferably 0.1 to 100 parts by mass and more preferably 1 to 10 parts by mass with respect to 100 parts by mass of the urethane prepolymer. In such a range, the curability and physical properties are excellent.

  The curable resin composition according to the second aspect of the present invention contains additives other than the above-mentioned blocked urethane prepolymer and moisture latent curing agent, as long as the object of the present invention is not impaired. Can do. Specific additives are the same as those of the curable resin composition of the first aspect of the present invention.

The curable resin composition of the second aspect of the present invention can be used as a one-component or two-component curable resin composition.
When the curable resin composition of the second aspect of the present invention is a one-pack type, a blocked urethane prepolymer, a moisture latent curing agent, and an epoxy resin and additives used as necessary Can be prepared under conditions where the moisture is thoroughly dried and moisture is removed, and may be stored in a container free from moisture.

  When the curable resin composition of the second aspect of the present invention is a two-component type, for example, an epoxy resin that is used as necessary, a main agent containing a blocked urethane prepolymer, a moisture latent curing agent, and the like. , And a curing agent mixed with additives can be prepared and mixed for use. In addition, an additive can also be added to a main ingredient.

As a method for using the curable resin composition of the second aspect of the present invention, for example, it is preferable to include a moisture heating step of heating the curable resin composition of the second aspect of the present invention in the presence of moisture. .
When the curable resin composition of the second aspect of the present invention is heated in the presence of moisture, the moisture latent curing agent contained in the curable resin composition is hydrolyzed to produce an amine and react with an isocyanate group. . In the curable resin composition according to the second aspect of the present invention, the isocyanate group is bonded to the tertiary carbon atom, so that the reactivity with the amine is low and the pot life can be extended.

Further, the blocked isocyanate group is heated in the presence of moisture, whereby the blocking agent is removed and an isocyanate group is generated. The produced isocyanate groups react with the amine produced from the moisture latent curing agent and cure.
Further, in the urethane prepolymer, the isocyanate group is partially or wholly blocked, so that the length of pot life can be adjusted by the blocking rate.

In the moisture heating step, the heating temperature is preferably 50 ° C. or higher, and more preferably 60 to 80 ° C. In such a temperature range, the deblocking reaction tends to proceed. In the moisture heating step, the humidity in the air may be 30% RH or more, or water may be added to the system. A moisture heating process is mentioned as one of the aspects with preferable stirring with an electric stirrer, for example, heating in a warm bath.

The curable resin composition of the 2nd aspect of this invention can be constructed in a construction process after a moisture heating process.
Examples of the adherend include mortar, earthenware, and metal. A construction method in particular is not restrict | limited, For example, it can construct using a brush, a iron, and a roller.

  Applications of the curable resin composition of the second aspect of the present invention include, for example, sealing materials, adhesives, coating materials, primers, and paints.

  As described above, the curable resin composition of the present invention can adjust the length of pot life and is excellent in storage stability. This is because (1) an isocyanate group bonded to a tertiary carbon atom has a larger steric hindrance around the tertiary carbon atom than an isocyanate group bonded to a secondary carbon atom. The urethane prepolymer having an isocyanate group bonded to the urethane has a low reactivity with the moisture latent curing agent, and (2) the isocyanate group bonded to the tertiary carbon atom has a low reactivity. This is because the block ratio of the prepolymer can be adjusted, and (3) the blocked urethane prepolymer blocked with a moisture latent curing agent is deblocked by heating in the presence of moisture. The inventor guesses. Note that such a mechanism is only an estimation of the present inventor, and even if the mechanism is different, it is within the scope of the present invention.

  EXAMPLES Next, although an Example demonstrates this invention concretely, this invention is not limited to these Examples.

1. Preparation of urethane prepolymer The components shown in Table 1 were mixed in the amounts shown in Table 1 (units are parts by mass), and reacted in the presence of tin catalyst at 80 ° C for 8 hours with stirring. TMXDI-based urethane prepolymers 1 to 3 were prepared. In Table 1, the polyol and the polyisocyanate are prepared so that NCO / OH is 2.0 in terms of molar ratio.

The details of each component in Table 1 are as follows.
Acrylic polyol: ARUFON UH-2000, manufactured by Toagosei Co., Ltd. PPG polyol: EXL5030 (polypropylene glycol), manufactured by Asahi Glass Co., Ltd. Plasticizer: ARUFON UP-1000 (acrylic plasticizer), manufactured by Toagosei Co., Ltd. Xylylene diisocyanate, manufactured by Cytec Co., Ltd. OHV in Table 1 represents a hydroxyl value, and the unit is mgKOH / g.

2. Preparation of blocking agent modified urethane prepolymer The components shown in Table 2 were mixed in the amounts shown in Table 2 (units are parts by mass), reacted at 100 ° C. for 5 hours with stirring, and then PP0 to PP12. Each block agent modified urethane prepolymer was prepared. Table 2 shows the NCO group blocking rate of each block agent-modified urethane prepolymer.

The details of each component in Table 2 are as follows.
Urethane prepolymer 1: Urethane prepolymer 1 prepared as described above
Urethane prepolymer 2: Urethane prepolymer 2 prepared as described above
Urethane prepolymer 3: urethane prepolymer 3 prepared as described above
3,5-dimethylpyrazole (MW 96.13): manufactured by Otsuka Chemical Co., Ltd., cyclohexanone oxime (MW 113.16): reagent, acetooxime (MW 73.09): reagent, butanone oxime (MW 87.12): reagent

  Storage stability (viscosity, thixo index value, rate of increase), pot life (tack) of each composition obtained by mixing each component shown in Table 3 in the amount shown in Table 3 (unit is part by mass) Free time), adhesiveness, and tensile test (maximum strength, elongation) were evaluated as follows. The results are shown in Table 3.

3. Evaluation (1) Storage stability Viscosity immediately after preparation of the obtained composition (initial) was measured at 20 ° C. using a BS viscometer at rotation speeds of 1 rpm and 10 rpm, and the thixo index value (TI) was determined. Asked. The thixo index value is a viscosity ratio measured at a rotational speed of 1 rpm and 10 rpm [T. I. = (Viscosity at 1 rpm) / (viscosity at 10 rpm)]. The higher the thixo index value, the higher the thixotropy.
The viscosity after curing for 3 days at 60 ° C. for each of these compositions was measured in the same manner to obtain a thixo index value.

  The rate of increase is the ratio of the viscosity measured at a rotational speed of 1 rpm after curing at 60 ° C. for 3 days to the viscosity of the composition measured at an initial rotational speed of 1 rpm [Increase rate = (after curing at 60 ° C. for 3 days. Viscosity measured at a rotational speed of 1 rpm) / (viscosity of these compositions measured at an initial rotational speed of 1 rpm)]. The higher the rate of increase, the better the storage stability.

(2) Pot life time The obtained composition was allowed to stand in an atmosphere of 20 ° C. and 55% RH and in an atmosphere of 40 ° C. and 60% RH, and the surface of the composition according to JIS A 5758: 1997. The time until tack disappears (tack free time) was measured. The unit of pot life is basically indicated as “minutes”, and h indicates “hours”.

(3) Adhesiveness The adhesiveness of the obtained composition to mortar was tested.
A mortar plate having a length of 7 cm and a width of 7 cm was used as the adherend.
A test specimen was prepared by applying the obtained composition to a mortar plate with a thickness of 4 mm. This specimen was left for 14 days in an atmosphere of 20 ° C. and 55% RH.
Next, the specimen after standing was subjected to a hand peeling test by knife cutting, and the state of the adhesive interface was observed. For the adhesiveness, a case where the state of failure was a cohesive failure of the composition was evaluated as ◯, and a case where the interface was broken was evaluated as x.

(4) Tensile test The obtained composition was cured for 28 days in an atmosphere of 20 ° C. and 55% RH. From this cured product, a test of dumbbell No. 3 was performed according to JIS K 6251-1993. A piece was collected, and the obtained test piece was pulled at a tensile speed of 100 mm / min to conduct a tensile test, and the maximum strength and elongation were measured.

The details of each component shown in Table 3 are as follows.
PP0 to PP12: Each block agent modified urethane prepolymer prepared as described above. Liquid epoxy resin: YD128, manufactured by Tohto Kasei Co., Ltd. Colloidal calcium carbonate: Viscolite MBP, manufactured by Shiroishi Kogyo Co., Ltd. Heavy calcium carbonate: Super S, manufactured by Maruo Calcium Co., Ltd., titanium oxide: R-820, manufactured by Takehara Chemical Industry Co., Ltd., carbon black: Asahi Thermal, manufactured by Asahi Carbon Co., Ltd., epoxy silane: (γ-glycidoxypropyltrimethoxysilane) A187, Nihon Unicar Company Product: Ketimine: HOK01 (Ketimine in combination with NBDA and MIPK. MW: 290), manufactured by Japan Epoxy Resin Co., Ltd.

  As is apparent from Table 3, the curable resin compositions of the examples can be set to have a longer pot life than the comparative examples. Moreover, the curable resin composition of an Example has shown the favorable result in storage stability and adhesiveness.

It turns out that the curable resin composition of an Example can adjust the length of pot life by changing the block formation rate of a urethane prepolymer. For example, when Example 1, Example 2 and Comparative Example 1 are compared, the pot life is increased by increasing the blocking rate. In Examples 5-6, as in the reference example 7 to 10, to adjust the blocking rate of the entire urethane prepolymer by blending different urethane prepolymer having blocked rate of this a curable resin composition It is possible to adjust the length of pot life.

Comparing Example 7 with Example 5, by the addition of further epoxy resin as in Example 5, it can be seen that it is possible to shorten the pot life of a curable resin composition.

Claims (12)

  A curable resin composition comprising a urethane prepolymer having an isocyanate group bonded to a tertiary carbon atom, a moisture latent curing agent containing ketimine and / or oxazolidine, and a blocking agent containing a pyrazole compound. A blocked urethane prepolymer obtainable by a reaction of a part or all of the isocyanate group of the urethane prepolymer having an isocyanate group bonded to a tertiary carbon atom with a blocking agent containing a pyrazole compound;
A curable resin composition containing a moisture latent curing agent comprising ketimine and / or oxazolidine.   The urethane prepolymer is obtained by reaction of a polyisocyanate compound having an isocyanate group bonded to a tertiary carbon atom and a polyol compound, and the polyol compound is a polyether polyol, a polyester polyol, an acrylic polyol, a polymer polyol, or a polycarbonate polyol. The polybutadiene polyol, hydrogenated polybutadiene polyol, ethylene glycol, diethylene glycol, propylene glycol, dipropylene glycol, butanediol, pentanediol, and hexanediol are at least one selected from the group consisting of Curable resin composition.   The curable resin composition according to claim 3, wherein the acrylic polyol has a molecular weight of 2000 to 20000.   The curable resin composition according to claim 3 or 4, wherein the acrylic polyol has a hydroxyl value of 20 to 150. The ketimine is obtained from methyl isopropyl ketone or methyl t-butyl ketone and H ₂ N (CH ₂ CH ₂ O) ₂ (CH ₂ ) ₂ NH ₂ , methyl isopropyl ketone or methyl t-butyl ketone and 1,3- One obtained from bisaminomethylcyclohexane, one obtained from methyl isopropyl ketone or methyl t-butyl ketone and dimethylene amine of norbornane skeleton, one obtained from methyl isopropyl ketone or methyl t-butyl ketone and metaxylylene diamine, The curable resin composition according to claim 1, which is at least one selected from the group consisting of methyl isopropyl ketone or methyl t-butyl ketone and polyamidoamine.   The amount of the blocking agent is such that the molar ratio [NH / NCO] of the imino group of the pyrazole compound to the isocyanate group contained in the urethane prepolymer is 0.03 to 1. A curable resin composition according to claim 1. The amount of the moisture latent curing agent is the molar ratio of all isocyanate groups (NCO) in the urethane prepolymer to imino groups (NH) and / or amino groups (NH ₂ ) in the cured curing agent [ NCO / (NH and / or NH _2)] the curable resin composition according to any one of claims 1 to 7 is from 0.1 to 10.   The curable resin composition according to claim 2, wherein a blocking ratio of the blocked urethane prepolymer is 1 to 100%.   Furthermore, the curable resin composition in any one of Claims 1-9 containing an epoxy resin.   The amount of the said epoxy resin is 0.1-100 mass parts with respect to 100 mass parts of said urethane prepolymers, The curable resin composition of Claim 10. The curable resin composition according to claim 1, which is used for a sealing material, an adhesive, a coating material, a primer, or a paint.