JP5294887B2 - One-component thermosetting adhesive composition - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a one-component type thermosetting adhesive composition securing a favorable work environment, excellent in storage stability, having adhesiveness to both flexible and hard films, and providing sufficient adhesion strength even at a process temperature lower than 200&deg;C. <P>SOLUTION: The one-component type thermosetting adhesive composition includes a carboxy-containing macropolyol and a compound having at least two carbodiimide groups in a molecule. This one-component type thermosetting adhesive composition is excellent in storage stability, has adhesion to a soft film as well as adhesion to a hard film, and is excellent in low-temperature curability. Accordingly, the one-component type thermosetting adhesive composition is preferably used as an adhesive for steel sheet lamination. <P>COPYRIGHT: (C)2010,JPO&amp;INPIT

Description

  The present invention relates to a one-component thermosetting adhesive composition, and more particularly to a one-component thermosetting adhesive composition suitably used as an adhesive for steel plate lamination.

  Conventionally, various adhesives containing macro polyols and blocked isocyanate compounds have been proposed as adhesives for steel sheet lamination. For example, for plastic sheet laminated steel sheets containing polyester resin, blocked isocyanate, epoxy compound and catalyst. Adhesives have been proposed (see, for example, Patent Document 1).

JP 2006-31678 A

  However, in an adhesive containing a blocked isocyanate as described in Patent Document 1, a free blocking agent produced by deblocking the blocked isocyanate may generate odor and lower the working environment. is there. Moreover, in the adhesive which mix | blended block isocyanate, when a catalyst is added in order to deblock a blocking agent rapidly, the storage stability of an adhesive agent may fall.

  In recent years, the types of laminate films tend to be diversified, and it has been encouraged to replace vinyl chloride films that have been used in the past with polyolefin films or polyester films. Therefore, an adhesive having both adhesiveness to a flexible film such as a polyolefin film and adhesiveness to a hard film such as a polyester film is desired.

  Furthermore, in recent years, design properties are required in the field of steel sheet lamination. For example, in order to prevent the embossed pattern from being crushed, lowering of the steel sheet processing temperature (less than 200 ° C.) is required. An adhesive having excellent curability below is desired.

  The object of the present invention is to ensure a good working environment, excellent in storage stability, having both adhesiveness to a flexible film and adhesiveness to a hard film, and even at a processing temperature of less than 200 ° C, An object of the present invention is to provide a one-component thermosetting adhesive composition capable of obtaining sufficient adhesive strength.

  In order to achieve the above object, the one-component thermosetting adhesive composition of the present invention contains a carboxy group-containing macropolyol and a compound having at least two carbodiimide groups in one molecule. Yes.

  In addition, the one-component thermosetting adhesive composition of the present invention is preferably obtained by reacting a carboxy group-containing macropolyol with a compound containing at least two carbodiimide groups in one molecule. .

  Moreover, in the one-component thermosetting adhesive composition of the present invention, it is preferable that the carboxy group concentration in the carboxy group-containing macropolyol is less than 0.1 mmol / g.

  The one-component thermosetting adhesive composition of the present invention preferably further contains a derivative of an alicyclic polyisocyanate.

In the one-component thermosetting adhesive composition of the present invention, the carboxy group concentration in the carboxy group-containing macropolyol is 0.05 mmol / g or more and less than 0.1 mmol / g,
In addition, it is preferable that the value of the following formula (1) is less than 0.15.

Formula (1) = (A) × (B) / (C)
(A): Carboxy group concentration (mmol / g) in the carboxy group-containing macropolyol
(B): Number of moles of carbodiimide compound in the one-component thermosetting adhesive composition (mol)
(C): Number of moles of carboxy group in the carboxy group-containing macropolyol (mol)
In addition, the one-component thermosetting adhesive composition of the present invention preferably has a viscosity value of 120% or less of the initial viscosity value after storage at 60 ° C. for 7 days.

  In addition, the one-component thermosetting adhesive composition of the present invention is preferably cured at a temperature of less than 200 ° C.

  In addition, the one-component thermosetting adhesive composition of the present invention is preferably used as an adhesive for laminating steel sheets.

  According to the one-component thermosetting adhesive of the present invention, storage stability can be improved without using blocked isocyanate, and both adhesiveness to a flexible film and adhesiveness to a hard film are combined. Furthermore, sufficient adhesive strength can be obtained at a processing temperature of less than 200 ° C.

  The one-component thermosetting adhesive of the present invention contains, as main components, a carboxy group-containing macropolyol and a compound having at least two carbodiimide groups in one molecule (hereinafter abbreviated as a carbodiimide compound). ing.

  The carboxy group-containing macropolyol is a compound having two or more hydroxyl groups and having a carboxy group in the side chain and having a number average molecular weight of 400 or more, for example, a polyisocyanate, a polyol, and an active hydrogen compound containing a carboxy group Can be obtained by reacting.

  In the present invention, examples of the polyisocyanate include diisocyanates such as aliphatic polyisocyanate, alicyclic polyisocyanate, araliphatic polyisocyanate, and aromatic polyisocyanate.

  Examples of the aliphatic polyisocyanate include hexamethylene diisocyanate (HDI), trimethylene diisocyanate, tetramethylene diisocyanate, pentamethylene diisocyanate, 1,2-, 2,3- or 1,3-butylene diisocyanate, 2,4,4. -Or aliphatic diisocyanates such as 2,2,4-trimethylhexamethylene diisocyanate.

Examples of the alicyclic polyisocyanate include 3-isocyanatomethyl-3,5,5-trimethylcyclohexyl isocyanate (isophorone diisocyanate, IPDI), 4,4'-, 2,4'- or 2,2'-dicyclohexyl. Methane diisocyanate or mixtures thereof (H ₁₂ MDI), 1,3- or 1,4-bis (isocyanatomethyl) cyclohexane or mixtures thereof (H ₆ XDI), 2,5- or 2,6-bis (isocyanatomethyl) ) Norbornane or a mixture thereof (NBDI), 1,3-cyclopentene diisocyanate, 1,4-cyclohexane diisocyanate, 1,3-cyclohexane diisocyanate, methyl-2,4-cyclohexane diisocyanate, methyl-2,6-cyclohexane diisocyanate Examples thereof include alicyclic diisocyanates such as anate.

  Examples of the araliphatic polyisocyanate include 1,3- or 1,4-xylylene diisocyanate or a mixture thereof (XDI), 1,3- or 1,4-tetramethylxylylene diisocyanate or a mixture thereof (TMXDI), Examples thereof include araliphatic diisocyanates such as ω, ω′-diisocyanato-1,4-diethylbenzene.

  Aromatic polyisocyanates include, for example, 4,4'-, 2,4'- or 2,2'-diphenylmethane diisocyanate or mixtures thereof (MDI), 2,4- or 2,6-tolylene diisocyanate or mixtures thereof (TDI), 4,4'-toluidine diisocyanate (TODI), 1,5-naphthalene diisocyanate (NDI), m- or p-phenylene diisocyanate or mixtures thereof, 4,4'-diphenyl diisocyanate, 4,4'-diphenyl ether Aromatic diisocyanates such as diisocyanates are mentioned.

  Examples of the polyisocyanate include multimers of the above polyisocyanates (for example, dimers, trimers (for example, isocyanurate-modified products), pentamers, heptamers, etc.), allophanate-modified products ( For example, modified allophanate produced by reaction of polyisocyanate and alcohol), modified biuret (for example, modified biuret produced by reaction of polyisocyanate with water or amines), modified urea ( For example, urea-modified products produced by reaction of polyisocyanate and diamine, etc.), oxadiazine trione (eg, oxadiazine trione produced by reaction of polyisocyanate and carbon dioxide gas), carbodiimide-modified product (polyisocyanate modified product). Carbodiimi produced by decarboxylation condensation reaction Modified products, etc.) and the like.

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

  As polyisocyanate, Preferably, alicyclic diisocyanate, More preferably, IPDI is mentioned.

  In the present invention, examples of the polyol include a low molecular weight polyol and a high molecular weight polyol (macropolyol).

  The low molecular weight polyol is a compound having two or more hydroxyl groups and a number average molecular weight of less than 400, such as ethylene glycol, propylene glycol, 1,3-propanediol, 1,4-butylene glycol, 1,3-butylene glycol. 1,2-butylene glycol, 1,5-pentanediol, 1,6-hexanediol, neopentyl glycol, alkane (7-22) diol, diethylene glycol, triethylene glycol, dipropylene glycol, 3-methyl-1, 5-pentanediol, 2-ethyl-2-butyl-1,3-propanediol, alkane-1,2-diol (C17-20), 1,3- or 1,4-cyclohexanedimethanol and mixtures thereof; 1,4-cyclohexanediol, bisphenol hydride Dihydric alcohols such as diol A, 1,4-dihydroxy-2-butene, 2,6-dimethyl-1-octene-3,8-diol, bisphenol A, for example, trihydric alcohols such as glycerin and trimethylolpropane, For example, tetravalent alcohols such as tetramethylolmethane (pentaerythritol) and diglycerin, for example, pentahydric alcohols such as xylitol, such as sorbitol, mannitol, allitol, iditol, dulcitol, altritol, inositol, dipentaerythritol, etc. Examples thereof include monohydric alcohols, for example, 7-valent alcohols such as perseitol, and 8-valent alcohols such as sucrose.

  The high molecular weight polyol is a compound having two or more hydroxyl groups and a number average molecular weight of 400 or more, for example, polyether polyol, polyester polyol, polycarbonate polyol, polyurethane polyol, epoxy polyol, vegetable oil polyol, polyolefin polyol, acrylic polyol, and And vinyl monomer-modified polyol.

  Examples of the polyether polyol include polypropylene glycol and polytetramethylene ether glycol.

  Examples of the polypropylene glycol include addition polymers of alkylene oxides such as ethylene oxide and propylene oxide (the random and / or two or more types of alkylene oxides) using the above-described low molecular weight polyols or aromatic / aliphatic polyamines as initiators. A block copolymer).

  Examples of the polytetramethylene ether glycol include a ring-opening polymer obtained by cationic polymerization of tetrahydrofuran, and amorphous polytetramethylene ether glycol obtained by copolymerizing the above-described dihydric alcohol with a polymerization unit of tetrahydrofuran.

  Examples of the polyester polyol include polycondensates obtained by reacting the above-described low molecular weight polyol (preferably a dihydric alcohol) with a polybasic acid under known conditions.

  Examples of the polybasic acid include oxalic acid, malonic acid, succinic acid, methyl succinic acid, glutaric acid, adipic acid, 1,1-dimethyl-1,3-dicarboxypropane, and 3-methyl-3-ethylglutaric acid. , Azelaic acid, sebacic acid, other saturated aliphatic dicarboxylic acids (having 11 to 13 carbon atoms) such as maleic acid, fumaric acid, itaconic acid, other unsaturated aliphatic dicarboxylic acids such as orthophthalic acid, isophthalic acid, Terephthalic acid, toluene dicarboxylic acid, naphthalene dicarboxylic acid, other aromatic dicarboxylic acids such as hexahydrophthalic acid, other alicyclic dicarboxylic acids such as dimer acid, hydrogenated dimer acid, het acid Acids and acid anhydrides derived from these carboxylic acids such as oxalic anhydride, Acid halides derived from succinic acid, maleic anhydride, phthalic anhydride, 2-alkyl (C12-C18) succinic anhydride, tetrahydrophthalic anhydride, trimellitic anhydride, and carboxylic acids thereof, for example, Examples include oxalic acid dichloride, adipic acid dichloride, and sebacic acid dichloride.

  Further, as the polyester polyol, for example, a hydroxyl group-containing vegetable oil fatty acid (for example, castor oil fatty acid containing ricinoleic acid, hydrogenated castor oil fatty acid containing 12-hydroxystearic acid, etc.) using the above low molecular weight polyol as an initiator, etc. Examples thereof include vegetable oil-based polyester polyols obtained by subjecting hydroxycarboxylic acid to a condensation reaction under known conditions.

  Polyester polyols obtained by ring-opening polymerization of lactones such as ε-caprolactone and γ-valerolactone, for example, using the above-described low molecular weight polyol (preferably dihydric alcohol) as an initiator, Examples include caprolactone polyol, polyvalerolactone polyol, and lactone polyester polyol obtained by copolymerizing the above-described dihydric alcohol.

  As the polycarbonate polyol, for example, a ring-opening polymer of ethylene carbonate using the above-described low molecular weight polyol (preferably a dihydric alcohol) as an initiator, for example, 1,4-butanediol, 1,5-pentanediol, Examples thereof include amorphous or crystalline polycarbonate polyols obtained by copolymerizing a dihydric alcohol such as 3-methyl-1,5-pentanediol or 1,6-hexanediol with a ring-opening polymer.

  Further, the polyurethane polyol is a ratio in which the equivalent ratio (OH / NCO) of the hydroxyl group (OH) to the isocyanate group (NCO) of the polyester polyol, polyether polyol and / or polycarbonate polyol obtained as described above exceeds 1, By making it react with the said polyisocyanate, it can be obtained as a polyester polyurethane polyol, a polyether polyurethane polyol, a polycarbonate polyurethane polyol, or a polyester polyether polyurethane polyol.

  Examples of the epoxy polyol include an epoxy polyol obtained by a reaction of the above-described low molecular weight polyol with a polyfunctional halohydrin such as epichlorohydrin or β-methylepichlorohydrin.

  Examples of the vegetable oil polyol include hydroxyl group-containing vegetable oils such as castor oil and coconut oil. For example, castor oil polyol, or ester-modified castor oil polyol obtained by reaction of castor oil fatty acid and polypropylene polyol can be used.

  Examples of the polyolefin polyol include polybutadiene polyol and partially saponified ethylene-vinyl acetate copolymer.

  Examples of the acrylic polyol include a copolymer obtained by copolymerizing a hydroxyl group-containing acrylate and a copolymerizable vinyl monomer copolymerizable with the hydroxyl group-containing acrylate.

  Examples of the hydroxyl group-containing acrylate include 2-hydroxyethyl (meth) acrylate, hydroxypropyl (meth) acrylate, hydroxybutyl (meth) acrylate, 2,2-dihydroxymethylbutyl (meth) acrylate, polyhydroxyalkyl maleate, Examples thereof include polyhydroxyalkyl fumarate. Preferably, 2-hydroxyethyl (meth) acrylate etc. are mentioned.

  Examples of the copolymerizable vinyl monomer include methyl (meth) acrylate, ethyl (meth) acrylate, propyl (meth) acrylate, isopropyl (meth) acrylate, butyl (meth) acrylate, isobutyl (meth) acrylate, and s-butyl ( Alkyls such as (meth) acrylate, t-butyl (meth) acrylate, pentyl (meth) acrylate, isopentyl (meth) acrylate, hexyl (meth) acrylate, isononyl (meth) acrylate, 2-ethylhexyl (meth) acrylate, cyclohexyl acrylate, etc. (Meth) acrylates (1 to 12 carbon atoms), for example, aromatic vinyl such as styrene, vinyltoluene and α-methylstyrene, for example, vinyl cyanide such as (meth) acrylonitrile, ) Vinyl monomers containing carboxyl groups such as acrylic acid, fumaric acid, maleic acid, itaconic acid, or alkyl esters thereof such as ethylene glycol di (meth) acrylate, butylene glycol di (meth) acrylate, hexanediol di (meth) ) Acrylates, oligoethylene glycol di (meth) acrylates, alkane polyol poly (meth) acrylates such as trimethylolpropane di (meth) acrylate, trimethylolpropane tri (meth) acrylate, such as 3- (2-isocyanate-2- And vinyl monomers containing an isocyanate group such as propyl) -α-methylstyrene.

  The acrylic polyol can be obtained by copolymerizing these hydroxyl group-containing acrylate and copolymerizable vinyl monomer in the presence of a suitable solvent and polymerization initiator.

  The acrylic polyol includes, for example, silicone polyol and fluorine polyol.

  Examples of the silicone polyol include an acrylic polyol in which a silicone compound containing a vinyl group such as γ-methacryloxypropyltrimethoxysilane is blended as the copolymerizable vinyl monomer in the copolymerization of the acrylic polyol described above. .

  As the fluorine polyol, for example, in the copolymerization of the acrylic polyol described above, as the copolymerizable vinyl monomer, for example, an acrylic polyol in which a fluorine compound containing a vinyl group such as tetrafluoroethylene or chlorotrifluoroethylene is blended may be mentioned. .

  The vinyl monomer-modified polyol can be obtained by a reaction between the above-described high molecular weight polyol and a vinyl monomer.

  The high molecular weight polyol is preferably a high molecular weight polyol selected from polyether polyol, polyester polyol and polycarbonate polyol.

  Examples of the vinyl monomer include the above-described alkyl (meth) acrylate, vinyl cyanide, vinylidene cyanide, and the like. These vinyl monomers can be used alone or in combination of two or more. Of these, alkyl (meth) acrylate is preferable.

  The vinyl monomer-modified polyol is obtained by reacting these high molecular weight polyol and vinyl monomer in the presence of a radical polymerization initiator (for example, persulfate, organic peroxide, azo compound, etc.), for example. Can be obtained.

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

  As the polyol, polyester polyol is preferable.

  In the present invention, an active hydrogen compound containing a carboxy group (hereinafter abbreviated as a carboxy group-containing active hydrogen compound) is a compound having a carboxy group and at least two active hydrogen groups in one molecule.

  The active hydrogen group that the carboxy group-containing active hydrogen compound has is a group that reacts with an isocyanate group, and examples thereof include a hydroxyl group, an amino group, a carboxy group, and an epoxy group.

  Examples of the carboxy group-containing active hydrogen compound include 2,2-dimethylolacetic acid, 2,2-dimethylollactic acid, 2,2-dimethylolpropionic acid, 2,2-dimethylolbutanoic acid, 2,2-dimethylolbutyric acid, Examples include dihydroxycarboxylic acids such as 2,2-dimethylolvaleric acid, diaminocarboxylic acids such as lysine and arginine, or metal salts and ammonium salts thereof.

  These carboxy group-containing active hydrogen compounds can be used alone or in combination of two or more.

  As the carboxy group-containing active hydrogen compound, dihydroxycarboxylic acid is preferable, and 2,2-dimethylolpropionic acid is more preferable.

  In order to obtain a carboxy group-containing macropolyol, the polyisocyanate, the polyol, and the carboxy group-containing active hydrogen compound are mixed with the active hydrogen group (of the polyol and the carboxy group-containing active hydrogen compound with respect to the isocyanate group of the polyisocyanate). The active hydrogen group (hydroxyl group) and the total amount of active hydrogen groups of the carboxy group-containing active hydrogen compound are mixed at a ratio of excess and reacted.

  More specifically, for example, the equivalent ratio of the active hydrogen group of the polyol and the carboxy group-containing active hydrogen compound to the isocyanate group (NCO) of the polyisocyanate, the polyisocyanate, the polyol, and the carboxy group-containing active hydrogen compound ( The active hydrogen group / NCO) is, for example, blended and reacted at a ratio of 1 or more, preferably 1 to 5, more preferably 1.05 to 2.

  In this reaction, for example, a known polymerization method such as bulk polymerization or solution polymerization can be used.

  In bulk polymerization, for example, while stirring a polyisocyanate under a nitrogen stream, a polyol and a carboxy group-containing active hydrogen compound are added thereto, and the reaction temperature is 40 to 150 ° C, more preferably 50 to 120 ° C. Is reacted until the unreacted isocyanate group disappears.

  In solution polymerization, a polyisocyanate, a polyol and a carboxy group-containing active hydrogen compound are added to an organic solvent, and the reaction temperature is 40 to 120 ° C., more preferably 50 to 90 ° C., preferably, the unreacted isocyanate group disappears. React until.

The disappearance of the unreacted isocyanate group is confirmed, for example, by measuring the infrared absorption spectrum using FT-IR and confirming that there is no NCO peak (absorption peak near 2250 cm ⁻¹ ).

  Examples of the organic solvent include ketones such as acetone, methyl ethyl ketone, methyl isobutyl ketone, and cyclohexanone; nitriles such as acetonitrile; alkyl esters such as methyl acetate, ethyl acetate, butyl acetate, and isobutyl acetate; Aliphatic hydrocarbons such as hexane, n-heptane, and octane, for example, alicyclic hydrocarbons such as cyclohexane and methylcyclohexane, for example, aromatic hydrocarbons such as toluene, xylene, and ethylbenzene, such as methyl cellosolve acetate , Ethyl cellosolve acetate, methyl carbitol acetate, ethyl carbitol acetate, ethylene glycol ethyl ether acetate, propylene glycol methyl ether acetate, 3-methyl-3-methoxy Glycol ether esters such as butyl acetate and ethyl-3-ethoxypropionate, for example, ethers such as diethyl ether, tetrahydrofuran and dioxane, such as methyl chloride, methylene chloride, chloroform, carbon tetrachloride, methyl bromide, iodine Halogenated aliphatic hydrocarbons such as methylene chloride and dichloroethane, for example, polar aprotics such as N-methylpyrrolidone, dimethylformamide, N, N′-dimethylacetamide, dimethylsulfoxide, hexamethylphosphonylamide, etc. .

  Furthermore, in the above polymerization reaction, a known urethanization catalyst such as amines and organometallic compounds may be added as necessary.

  Examples of the amines include tertiary amines such as triethylamine, triethylenediamine, bis- (2-dimethylaminoethyl) ether, N-methylmorpholine, and quaternary ammonium salts such as tetraethylhydroxylammonium, such as imidazole, Examples thereof include imidazoles such as 2-ethyl-4-methylimidazole.

  Examples of organometallic compounds include tin acetate, tin octylate, tin oleate, tin laurate, dibutyltin diacetate, dimethyltin dilaurate, dibutyltin dilaurate, dibutyltin dimercaptide, dibutyltin maleate, dibutyltin dilaurate, dibutyltin Organic tin compounds such as dineodecanoate, dioctyltin dimercaptide, dioctyltin dilaurate, dibutyltin dichloride, for example, organic lead compounds such as lead octoate and lead naphthenate, for example, organic nickel compounds such as nickel naphthenate, For example, organic cobalt compounds such as cobalt naphthenate, for example, organic copper compounds such as copper octenoate, for example, organic titanium compounds such as titanium (IV) tetrabutoxide, such as bismuth octylate, bismuth neodecanoate, etc. Organobismuth compounds, and the like.

  Furthermore, examples of the urethanization catalyst include potassium salts such as potassium carbonate, potassium acetate, and potassium octylate.

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

  The preparation of the carboxy group-containing macropolyol is not limited to this. For example, the above-described dihydroxycarboxylic acid, polybasic acid, and other high molecular weight polyol and / or low molecular weight polyol blended as necessary, It can also be prepared as a polyester polyol containing a carboxy group in the side chain by polycondensation under known conditions.

  In the present invention, the carboxy group-containing macropolyol has a carboxy group concentration (the number of moles of carboxy groups in 1 g of the carboxy group-containing macropolyol), for example, less than 0.12 mmol / g, preferably less than 0.09 mmol / g. For example, 0.005 mmol / g or more, preferably 0.05 mmol / g or more.

  The viscosity (25 ° C.) of the carboxy group-containing macropolyol is, for example, 1000 to 1000000 mPa · s, preferably 2000 to 500000 mPa · s, and the acid value is, for example, 0.28 to 5.61 mgKOH / g, Preferably, it is 2.8 to 5.05 mg KOH / g, and the hydroxyl value is, for example, 2.8 to 224 mg KOH / g, preferably 11.2 to 112 mg KOH / g.

  In addition, the carboxy group-containing macropolyol can be prepared, for example, as a carboxy group-containing macropolyol solution by dissolving it in the organic solvent described above. In such a case, the solid content concentration of the carboxy group-containing macropolyol in the carboxy group-containing macropolyol solution is, for example, 10 to 90% by weight, preferably 20 to 85% by weight.

  In the present invention, a carbodiimide compound can be prepared, for example, by partially reacting a polyisocyanate with a hydrophobic active hydrogen-containing compound and carbodiimidizing the polyisocyanate.

Examples of the polyisocyanate include polyisocyanates similar to the polyisocyanates used in the preparation of the carboxy group-containing macropolyol. For example, aromatic polyisocyanates such as MDI, TDI, TODI, and NDI, for example, aromatics such as XDI and TMXDI. Aliphatic polyisocyanates, for example, alicyclic polyisocyanates such as IPDI, H ₁₂ MDI, H ₆ XDI, and NBDI, for example, aliphatic polyisocyanates such as HDI, and the like.

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

  As the polyisocyanate, an aromatic polyisocyanate is preferable, and TDI is more preferable.

  The hydrophobic active hydrogen-containing compound is a hydrophobic compound containing an active hydrogen group capable of reacting with an isocyanate group, for example, a hydroxyl group, an amino group, a mercapto group, a carboxyl group, and the like, for example, butyl alcohol, hexyl alcohol, Cyclohexyl alcohol, heptanol, octanol, 2-ethylhexanol (2-ethylhexyl alcohol) (carbon number 8), nonyl alcohol, isononyl alcohol, decanol (carbon number 10), lauryl alcohol (carbon number 12), myristyl alcohol (carbon number) 14), cetyl alcohol (16 carbon atoms), stearyl alcohol (18 carbon atoms), oleyl alcohol (18 carbon atoms), eicosanol (20 carbon atoms), phenol and its derivatives, benzyl alcohol and its derivatives, phene Alcohols such as butyl alcohol and derivatives thereof, naphthol and derivatives thereof, such as butylamine, hexylamine, cyclohexylamine, octylamine, 2-ethylhexylamine, nonylamine, isononylamine, decylamine (carbon number 10), laurylamine (carbon 12), myristylamine (14 carbon atoms), cetylamine (16 carbon atoms), stearylamine (18 carbon atoms), oleylamine (18 carbon atoms), eicosamine (20 carbon atoms), dipropylamine, diisopropylamine, dibutylamine , Dicyclohexylamine, dioctylamine, aniline and its derivatives, monoamines such as benzylamine and its derivatives, such as butyl mercaptan, cyclohexyl mercaptan, octyl mercap Mercaptans, such as butanoic acid, hexanoic acid, cyclohexane acid, octanoic acid, nonanoic acid, decanoic acid, dodecanoic acid, benzoic acid and derivatives thereof And carboxylic acids.

  These hydrophobic active hydrogen-containing compounds can be used alone or in combination of two or more.

  The hydrophobic active hydrogen-containing compound is preferably an alcohol, more preferably an alcohol having 4 to 18 carbon atoms, and particularly preferably an alcohol having 6 to 18 carbon atoms.

  The carbodiimide compound is obtained by first partially reacting a polyisocyanate with a hydrophobic active hydrogen-containing compound and then carbodiimidizing the polyisocyanate reacted with the hydrophobic active hydrogen-containing compound, or First, after the polyisocyanate is carbodiimidized, the remaining isocyanate groups of the carbodiimidized polyisocyanate are reacted with a hydrophobic active hydrogen-containing compound.

  In the former method, the proportion (modification rate) at which the hydrophobic active hydrogen-containing compound is partially reacted with the polyisocyanate is the ratio of the hydrophobic active hydrogen-containing compound reacted to the whole carbodiimide compound. Is, for example, a ratio of 5 to 80% by weight, preferably 7 to 50% by weight.

  Further, in the former method, in order to partially react the polyisocyanate with the hydrophobic active hydrogen-containing compound, the reaction temperature of the polyisocyanate and the hydrophobic active hydrogen-containing compound is set at the above-described ratio. For example, the reaction may be carried out at 20 to 150 ° C., preferably 70 to 120 ° C., and the reaction time is, for example, 1 to 10 hours, preferably 1 to 5 hours. As a result, the hydrophobic active hydrogen-containing compound is partially introduced into the isocyanate compound.

  In the former method, in order to carbodiimidize the isocyanate compound reacted with the hydrophobic active hydrogen-containing compound, a known method may be used, and the isocyanate group is decarbonized using a carbodiimidization catalyst.

  The carbodiimidization catalyst is not particularly limited, but an organic phosphorus compound is preferably used, and a phospholene oxide compound is more preferably used from the viewpoint of catalytic activity.

  Examples of such phospholene oxide compounds include 3-methyl-1-phenyl-2-phospholene-1-oxide, 3-methyl-1-ethyl-2-phospholene-1-oxide, and 1,3-dimethyl. 2-phospholene-1-oxide, 1-phenyl-2-phospholene-1-oxide, 1-ethyl-2-phospholene-1-oxide, 1-methyl-2-phospholene-1-oxide and their double bonds Examples include isomers.

  As the phospholene oxide-based compound, preferably, 3-methyl-1-phenyl-2-phospholene-1-oxide, which is industrially easily available, can be mentioned.

  These carbodiimidization catalysts can be used alone or in combination of two or more. The ratio of using the carbodiimidization catalyst is preferably 0.01 to 20 parts by weight, more preferably 0.05 to 100 parts by weight with respect to 100 parts by weight of the isocyanate compound reacted with the hydrophobic active hydrogen-containing compound. 10 parts by weight.

  The carbodiimidization is performed using the above-described carbodiimidization catalyst, for example, in an inert gas atmosphere, the reaction temperature is, for example, 30 to 200 ° C., preferably 60 to 180 ° C., and the reaction time is, for example, The reaction is performed for 1 to 50 hours, preferably 3 to 40 hours. Thereby, a carbodiimide compound having a hydrophobic group at the molecular end can be obtained.

  And in such carbodiimidization, the above-mentioned reaction conditions are set such that the average degree of polymerization of the obtained carbodiimide compound, that is, the average number of carbodiimide groups (the number of carbodiimide groups contained in one molecule of carbodiimide compound) is 2 or more, for example It controls so that it may become 2-10, Preferably it is 2-5.

  In the latter method, in order to carbodiimidize the polyisocyanate, a reaction similar to the above may be performed using the same carbodiimidization catalyst as described above. Moreover, the average degree of polymerization of the carbodiimide compound obtained by this is controlled so that it may become 2 or more, for example, 2-10, preferably 2-5 similarly to the above.

  In the latter method, in order to react a hydrophobic active hydrogen-containing compound with the remaining isocyanate group of the carbodiimidized polyisocyanate, the carbodiimidized polyisocyanate and the hydrophobic active hydrogen-containing compound are mixed with the remaining active group. The reaction temperature is, for example, 20 to 150 ° C., preferably 70 to 120 ° C., and the reaction time is, for example, 1 to 10 hours, React in 2-5 hours. Thereby, a carbodiimide compound having a hydrophobic group at the molecular end can be obtained.

  In both the former method and the latter method, an organic solvent such as toluene, xylene, ethyl acetate, 2-butanone, acetone or the like can be used as a reaction medium in carbodiimidization.

  In such a case, the solid content concentration of the carbodiimide compound is, for example, 10 to 90% by weight, and preferably 20 to 85% by weight.

  Moreover, the number average molecular weights of the obtained carbodiimide compound are 300-10000, for example.

  Furthermore, in the preparation of the one-component thermosetting adhesive composition, together with the carboxy group-containing macropolyol obtained above and the carbodiimide compound obtained above, as optional components, for example, a polyisocyanate derivative, etc. Can be blended.

  By blending the polyisocyanate derivative, the adhesiveness of the one-component thermosetting adhesive composition can be further strengthened.

Polyisocyanate derivatives include polyisocyanates similar to the polyisocyanates used in the preparation of the carboxy group-containing macropolyol (for example, aromatic polyisocyanates such as MDI, TDI, TODI, and NDI, for example, aromatic fats such as XDI and TMXDI). Derivatives of aliphatic polyisocyanates, for example, alicyclic polyisocyanates such as IPDI, H ₁₂ MDI, H ₆ XDI, NBDI, and the like, for example, aliphatic polyisocyanates such as HDI, and the like. Modified body, biuret modified body, urea modified body, oxadiazine trione, etc. are mentioned. Preferred optional components include derivatives of aliphatic polyisocyanates and alicyclic polyisocyanates, and more preferably derivatives of alicyclic polyisocyanates.

  Then, the one-component thermosetting adhesive composition of the present invention is blended with each of the above components (that is, a carboxy group-containing macropolyol, a carbodiimide compound, an optional component, a polyisocyanate derivative), for example, 0 to 80 ° C., preferably 15 to 40 ° C., by stirring until uniform.

  In the preparation of the one-component thermosetting adhesive composition, the blending ratio of each component is, for example, 0.1 to 100 parts by weight, preferably 0.1 to 100 parts by weight, preferably 100 parts by weight of the carboxy group-containing macropolyol. 1 to 50 parts by weight.

  In addition, when a polyisocyanate derivative is blended in the one-component thermosetting adhesive composition, the blending ratio of the polyisocyanate derivative is, for example, 5 wt. Parts or less, preferably 2 parts by weight or less, usually 0.1 parts by weight or more.

  The one-component thermosetting adhesive composition of the present invention can also be obtained, for example, by blending and reacting a carboxy group-containing macropolyol and a carbodiimide compound.

  In such a reaction, for example, a known polymerization method such as the above-described bulk polymerization or the above-described solution polymerization can be used.

  When each of the above components is reacted, the equivalent ratio of the carbodiimide group (N = C = N) of the carbodiimide compound to the carboxy group (COOH) of the carboxy group-containing macropolyol is determined by reacting the carboxy group-containing macropolyol and the carbodiimide compound ( (N = C = N / COOH) is, for example, 0.3 to 100, preferably 0.5 to 50.

  As for the reaction conditions in such a reaction, the reaction temperature is, for example, 40 to 100 ° C., preferably 50 to 80 ° C., and the reaction time is, for example, 1 to 24 hours, preferably 2 to 12 hours. .

  Further, when a one-component thermosetting adhesive composition is obtained by a reaction of a carboxy group-containing macropolyol and a carbodiimide compound, for example, the one obtained by reacting the carboxy group-containing macropolyol with a carbodiimide compound is arbitrarily selected. As a component, the above-described polyisocyanate derivatives can be blended at the blending ratio described above.

  By blending the polyisocyanate derivative with the reaction of the carboxy group-containing macropolyol and the carbodiimide compound, the adhesiveness of the one-component thermosetting adhesive composition can be further strengthened.

  The one-component thermosetting adhesive composition of the present invention is prepared so that the value of the following formula (1) is, for example, less than 0.15, preferably less than 0.14. When the value of the following formula (1) is 0.15 or more, the storage stability of the one-component thermosetting adhesive composition may be lowered.

Formula (1) = (A) × (B) / (C)
(A): Carboxy group concentration (mmol / g) in the carboxy group-containing macropolyol
(B): Number of moles of carbodiimide compound in the one-component thermosetting adhesive composition (mol)
(C): Number of moles of carboxy group in the carboxy group-containing macropolyol (mol)
In the one-pack type thermosetting adhesive composition, for example, a rust preventive agent (rust preventive pigment), an antioxidant, and an ultraviolet absorber as long as they do not impair the excellent effects of the present invention. , Light stabilizer, silane coupling agent, epoxy resin, catalyst, coatability improver, leveling agent, nucleating agent, lubricant, mold release agent, antifoaming agent, plasticizer, surfactant, pigment, dye, organic or Additives such as inorganic fine particles, antifungal agents, flame retardants, and fillers can be added as appropriate.

  These additives may be added, for example, when preparing a carboxy group-containing macropolyol, may be added when preparing a carbodiimide compound, or may be added when mixing each component, You may add after preparation of a one-pack type thermosetting adhesive composition.

  And since the one-pack type thermosetting adhesive composition obtained in this way does not use blocked isocyanate as a raw material component, it is possible to suppress the generation of odor and keep the working environment in good condition. it can.

  Further, the one-component thermosetting adhesive composition thus obtained has excellent storage stability. Specifically, the viscosity value after storage at 60 ° C. for 7 days is the initial viscosity. For example, the value is 120% or less, preferably 115% or less.

  In addition, the one-component thermosetting adhesive composition thus obtained has both adhesiveness to a flexible film such as a polyolefin film and adhesiveness to a hard film such as a polyester film. .

  Furthermore, the one-component thermosetting adhesive composition thus obtained is excellent in low-temperature curability, and can be cured at a processing temperature of, for example, less than 200 ° C., preferably 180 ° C. or less.

  Therefore, the one-component thermosetting adhesive of the present invention can be suitably used as, for example, an adhesive for steel plate lamination.

  More specifically, the one-component thermosetting adhesive of the present invention can be used, for example, in the construction field (eg, exterior, interior, equipment, etc.), electrical equipment field (eg, home appliances, kitchen equipment, air conditioning, etc.), transportation, etc. Used in various industrial fields such as equipment field (for example, ships, automobiles, etc.), furniture field, miscellaneous goods field, for example, wall materials, door materials, outer plates, panels, decorative plates, cases, covers, steel plates, etc. It can be suitably used for attaching various films and imparting design properties.

  Hereinafter, the present invention will be described in detail with reference to Examples and Comparative Examples, but the present invention is not limited thereto.

Preparation Example 1 (Preparation of polyester polyol A)
Isophthalic acid 330.68 g, ethylene glycol 71.38 g, and neopentyl glycol 353.31 g were esterified at 180 to 220 ° C. in a nitrogen stream. Next, a predetermined amount of water was distilled, and then 402.57 g of sebacic acid was added, and further esterification was performed at 180 to 220 ° C. to obtain a polyester polyol A having a number average molecular weight of about 2,500.

Preparation Example 2 (Preparation of carbodiimide compound B)
To 435.5 g of tolylene diisocyanate (Mitsui Chemicals Polyurethane Co., Ltd., Cosmonate T-80), 162.8 g of 2-ethylhexyl alcohol was dropped and mixed so that the liquid temperature did not exceed 90 ° C., and then reacted for 1 hour. It was.

Thereafter, 258.3 g of ethyl acetate and 4.4 g of 3-methyl-1-phenyl-2-phospholene-1-oxide were further added, and the mixture was stirred at 80 ° C. for 20 hours under a nitrogen stream to be reacted. It was. After completion of the reaction, it was confirmed by infrared absorption spectrum measurement that the peak of the isocyanate group having an absorption wavelength of 2000 to 2300 cm ⁻¹ disappeared, and carbodiimide compound B having a solid content of 70% by weight was obtained. The carbodiimide compound B contained an average of about 3 carbodiimide groups in one molecule, and the molecular weight was 787.

Synthesis Example 1 (Synthesis of carboxy group-containing macropolyol C)
Polyester polyol A 474.36 g, dimethylolpropionic acid 1.37 g, 3-isocyanatomethyl-3,5,5-trimethylcyclohexyl isocyanate 38.68 g were stirred at 110 to 120 ° C. in a nitrogen stream, and urethane It was made to react. After confirming the disappearance of the NCO peak by infrared absorption spectrum measurement, 514.41 g of ethyl acetate was added and completely dissolved to synthesize a carboxy group-containing macropolyol C having a solid content of 50% by weight.

Synthesis Examples 2-7
Carboxy group-containing macropolyols D to H and polyester polyurethane polyol I were prepared in the same manner as in Synthesis Example 1, except that each component was blended in the blending formulation shown in Table 1.

  Table 1 shows the formulation of each synthesis example.

  In addition, the carboxy group concentration of each carboxy group-containing macropolyol and polyester polyurethane polyol, the viscosity at 25 ° C. (measured with an SB type viscometer in accordance with JIS K 7117), and the acid value (in terms of solid content, JIS K) Measured according to 6901). The results are shown in Table 1.

  The carboxy group concentration was calculated by the following formula (2).

Carboxy group concentration [mmol / g] = 1000 ra {(Mixed weight of carboxyl group-containing active hydrogen compound [g]) / (Molecular weight of carboxyl group-containing active hydrogen compound [g / mol])} / (Carboxy group-containing macropolyol Ingredient solids weight [g]) (2)
Example 1
Carboxyimide compound B 5.7 parts by weight is added to 1000 parts by weight of carboxy group-containing macropolyol C, and the mixture is stirred at 50 to 70 ° C. for 3 hours to react the carboxy group-containing macropolyol with the carbodiimide compound. A thermosetting adhesive composition was obtained.

Examples 2-37 and Comparative Examples 1-11
A one-component thermosetting adhesive composition of each example and each comparative example was obtained in the same manner as in Example 1 except that each component was blended according to the formulation shown in Tables 2-7.

  The one-component thermosetting adhesive compositions of Examples 20 and 21 were produced by uniformly mixing and stirring at room temperature without reacting the carboxy group-containing macropolyol and the carbodiimide compound.

  In addition, the one-component thermosetting adhesive compositions of Examples 36 and 37 were reacted with a carboxy group-containing macropolyol and a carbodiimide compound in the same manner as in Example 1, and then the alicyclic polyisocyanate derivative was converted to room temperature. The mixture was uniformly mixed and stirred.

  Tables 2 to 7 show the formulation of each example.

  The details of the abbreviations in Tables 2 to 7 are shown below.

Macropolyol C to H: Carboxy group-containing macropolyol, solid content 50% by weight
Macropolyol I: Polyester polyurethane polyol, solid content 50% by weight
Carbodiimide compound B: molecular weight 787, containing 3 carbodiimide groups in one molecule, solid content 70% by weight
Block isocyanate: Takenate B830 (manufactured by Mitsui Chemicals Polyurethanes, TDI adduct block, NV (solid content concentration) 55% by weight)
Derivatives of alicyclic polyisocyanate: VESTANAT T1890 / 100 (Degussa, isocyanurate modified form of isophorone diisocyanate)
Catalyst: Dioctyltin dilaurate Evaluation <Storage stability>
The one-component thermosetting adhesive composition of each Example and each Comparative Example was put in a glass bottle, and the viscosity at 25 ° C. was measured with an SB type viscometer in accordance with JIS K 7117. Furthermore, after storing this one-component thermosetting adhesive composition at 60 ° C. for 7 days, the viscosity at 25 ° C. was similarly measured. Further, the value obtained by dividing the value of the viscosity after storage by the value of the viscosity before storage was expressed as a percentage, which was used as an index of increase in the viscosity of the one-component thermosetting adhesive composition. The results are shown in Tables 2-7.

  In the one-component thermosetting adhesive compositions of Examples 20 and 21 (one-component thermosetting adhesive compositions prepared without reacting a carboxy group-containing macropolyol and a carbodiimide compound), the temperature is 60 ° C. When 3 to 5 hours passed, the carboxy group-containing macropolyol and the carbodiimide compound reacted, and thus the storage stability was not evaluated.

<Adhesive strength>
In each example and each comparative example, the one-component thermosetting adhesive composition was a steel plate (manufactured by Nippon Test Panel Co., Ltd., Parkerizing Palbond 3100) so that the coating amount after drying the organic solvent was 5 g / m ^2. It was applied to a treated chemical film coating plate (corresponding to JIS G 3141), and after drying the organic solvent, it was heated at 180 ° C. for 90 seconds, and immediately an untreated surface of the PET film (P- 60, 40 microns) or a treated surface of a CPP film (Toray Film Processing Co., Ltd., Treffan NO ZK-99, 60 microns). Subsequently, after press-bonding with a hot roll (roll temperature 90 ° C., linear pressure 7 N / cm, speed 1 mm / min), it is immersed in a bucket containing water for 30 seconds, and then dried at 60 ° C. for 30 minutes. Got. A peel test of this laminated steel sheet (manufactured by Intesco, Intesco precision universal material testing machine 201B, under 25 ° C., test piece width 25 mm, tensile speed 50 mm / min) was performed to measure peel strength. The results are shown in Tables 2-7.

  In Tables 2 to 7, IF indicates that the fracture mode was interfacial peeling (peeling between the film and the adhesive layer, or peeling between the adhesive layer and the steel plate).

Claims (8)

A carboxy group-containing macropolyol obtained by reacting a polyisocyanate, a polyol, and an active hydrogen compound containing a carboxy group;
A one-component thermosetting adhesive composition comprising a compound having at least two carbodiimide groups in one molecule. A carboxy group-containing macropolyol;
The one-component thermosetting adhesive composition according to claim 1, which is obtained by reacting a compound containing at least two carbodiimide groups in one molecule.   The one-pack type thermosetting adhesive composition according to claim 1 or 2, wherein the carboxy group concentration in the carboxy group-containing macropolyol is less than 0.1 mmol / g.   The one-component thermosetting adhesive composition according to any one of claims 1 to 3, further comprising a derivative of an alicyclic polyisocyanate. The carboxy group concentration in the carboxy group-containing macropolyol is 0.05 mmol / g or more and less than 0.1 mmol / g,
And the value of following formula (1) is less than 0.15, The one-pack type thermosetting adhesive composition in any one of Claims 1-4 characterized by the above-mentioned.
Formula (1) = (A) × (B) / (C)
(A): Carboxy group concentration (mmol / g) in the carboxy group-containing macropolyol
(B): Number of moles of carbodiimide compound in the one-component thermosetting adhesive composition (mol)
(C): Number of moles of carboxy group in the carboxy group-containing macropolyol (mol)   The one-component thermosetting adhesive composition according to any one of claims 1 to 5, wherein the viscosity value after storage at 60 ° C for 7 days is 120% or less of the initial viscosity value. object.   The one-component thermosetting adhesive composition according to any one of claims 1 to 6, which is cured at a temperature of less than 200 ° C.   The one-component thermosetting adhesive composition according to any one of claims 1 to 7, which is used as an adhesive for steel plate lamination.